O
Oatmeal
Using a lauryl sulfate-irritation model, Boyer and coworkers (1998) demonstrated the anti-inflammatory and healing properties of several processed oatmeal extracts from Avena Rheala and Avena Sativa. Incorporating 20 percent of each oatmeal extract in a petrolatum ointment resulted in a similar 60 percent inhibition of perfusion blood flow, a measure of inflammation following application of 50 μl of 1 percent solution of lauryl sulfate to the forearm of 12 healthy volunteers, compared to the control. Oatmeal is recommended by veterinarians for treating skin allergies in pets.
References
Boyer, F., Dane, G.S., Borrel, M.T., Dupuy, P., and Gall, Y., Anti-inflammatory properties of oatmeal extracts using a lauryl-sulfate irritation model, J. Dermatol. Sci., 16 (Suppl. 1):S217, 1998.
Oats
The first health claim permitted by the Food and Drug Administration (FDA) in the U.S.A. under the Nutrition Labelling and Education Act (1990) for a specific food was made for diets high in oatmeal, oat bran, or oat flour. These diets were associated with a reduction in coronary heart disease. Food and feed oats belong to the species Avena sativa. Katz et al. (2001a) was the first to report the beneficial effects of daily supplementing the diet of 50 healthy subjects with whole-grain oats or wheat cereal by ameliorating the fat-induced impairment of vascular reactivity. The results observed were comparable to that of vitamin E. In fact, endothelial dysfunction following acute fat ingestion was shown by Katz et al. (2001b) to be concomitant with ingestion of vitamin E and oats, but not wheat.
The reduction in blood-cholesterol levels by oats was attributed to the presence of high levels of soluble fiber in the bran. This proved to be a linear, high-molecular-weight β-glucan, composed of β-1,4-linked glucose units separated by a single β-1,3-linked glucose every two or three units (Braaten et al., 1999).
Behall and coworkers (1997) examined the hypolipidemic effects of this soluble fiber by incorporating it into a typical diet of 7 men and 16 women. They found that β-glucan reduced total and LDL cholesterol, particularly in subjects maintained on a high β-glucan diet (Table O.49). No changes in triacylglycerol levels were observed.
Using a randomized, blind, placebo-controlled crossover design, Braaten et al. (1999) further established the relationship between oat-bran consumption and reduction in blood cholesterol in hypercholesterolemic individuals. Davy et al. (2002) showed that the addition of two large servings of oats also significantly reduced total and LDL cholesterol, thereby reducing the risk of cardiovascular disease.
Oat mixed-linkage β-glucan [(163)(164)-β-D-glucan. (From Colleoni- Sirghie et al., Carbohydr. Polym., 54:237–249, 2003. With permission.)
TABLE O.49
Mean Plasma Lipids in Subjects on Controlled Diets
References
Behall, K., Schofield, D., and Hallfrisch, J., Effect of β-glucan in oat fiber extracts on blood lipids in men and women, J. Am. Coll. Nutr., 16:46–51, 1997.
Braaten, J.T., Wood, P.J., Scott, F.W., Wolneytz, M.S., Lowe, M.K., Bradley-White, P. and Collins, M.W., Oats β-glucan reduces blood cholesterol concentration in hypercholesterlemic subjects, Eur. J. Clin Nutr., 48:465–475, 1994.
Colleoni-Sirghie, M., Fulton, D.B., and White, P.J., Structural features of water soluble (1,3) (1,4)- b-D-glucans from high-b-glucan and traditional oat lines, Carbohydr. Polym., 54:237–249, 2003.
Davy, B.M., Davin, K.P., Ho, R.C., Beske, S.D., Davrath, L.R., and Melby, C.L., High-fiber oat cereal compared with wheat cereal consumption favorably alters LDL-cholesterol subclass and particle numbers in middle-aged and older men, Am. J. Clin. Nutr., 76: 351–358, 2002.
Katz, D.L., Nawaz, H., Boukhalil, J., Chan, W., Ahmadi, R., Giannamore, V., and Sarrel, P.M., Effects of oats and wheat cereals on endothelial responses, Prev. Med., 33:476–484, 2001a.
Katz, D.L., Nawaz, H., Boukhalil, J., Giannamore, C.V.T., Chan, W., Ahmadi, R., and Sarrel, P.M., Acute effects of oats and vitamin E on endothelial responses to ingested fat, Am. J. Prev. Med., 20:124–129, 2001b.
Oat avenanthramides
A group of novel alkaloids containing phenolic groups was identified by Collins (1989) in oat groats and hulls and identified as avenanthramides. They are substituted hydroxycinnamic-acid conjugates, with more than 25 types identified. The three most abundant avenanthramides, N-(4′-hydroxy-3′-cinnamoyl)-5-hydroxy-anthranilic acid (Bf), N-(4′-hydroxycinnamoyl)-5-hydroxy-anthranilic acid (Bp), and N-(3′,4′-dihydroxycinnamoyl)-5-hydroxyanthranilic acid (Bc), were shown to exhibit antioxidant activity using two in vitro systems (Scheme O.40) (Peterson et al, 2002). The levels of avenanthramides in oat groats were shown by Emmons and Peterson (2001) to be affected by genotype and growing conditions. Further breeding or growing in a particular environment could enhance the antioxidant capacity. Ji et al. (2003) showed for the first time that a diet supplemented with 0.1 percent synthetic Bc was tissue specific by only attenuating exerciseinduced ROS in the soleus muscle and lipid peroxidation in the heart of female SpragueDawley rats compared to the control. A recent study by Liu and coworkers (2004) provided further evidence for the anti-inflammatory and antiatherogenic properties of oat avenanthramides.
Avenanthramide R
Bp H
Bf OCH3
Bc OH
SCHEME O.40 Oat aventhramides Bc, Bp, and Bf structures. (Peterson et al., Food Chem., 79:473–478, 2002. With permission.)
References
Collins, F.W., Oat phenolics: Avenanthramides, novel substituted N-cinnamoylanthranilate alkaloids from oat groats and hulls, J. Agric. Food Chem., 37: 60–66, 1989.
Emmons, C.L. and Peterson, D.M., Antioxidant activity and phenolic contents of oat as affected by cultivar and location, Crop Sci., 41:1676–1681, 1999.
Ji, L.L., Lay, D., Chung, E., Fu, Y., and Peterson, D.M., Effects of avenanthramides on oxidant generation and antioxidant enzyme activity in exercised rats, Nutr. Res., 23:1579–1590, 2003.
Liu, L., Zubik, L., Collins, W.F., Marko, M.G., and Meydani, M., The antiatherogenic potential of oat phenolic compounds, Atherosclerosis, 175:39–49, 2004.
Peterson, D.M., Hahn, M.J., and Emmons, C.L., Oat avenanthamides exhibit antioxidant activities in vitro, Food Chem., 19:413–418, 2002.
Ocimum sanctum
Ocimum sanctum, an annual herb grown throughout India, is considered sacred by the Hindus as tulsi, or “holy basil” in English. It has been reported to possess therapeutic properties, such as anticarcinogenic, antiseptic, antirheumatic, antistress, antihelmintic, and antibacterial activities (Bhargava and Singh 1981; Singh et al., 1996; Singh and Majumdar, 1999; Godhwani et al., 1987, 1988). Singh and Majumdar (1997) attributed the antiinflammatory activity of O. sanctum to the ability of linolenic acid present in the fixed oil to block both the cyclooxygenase and lipoxygenase pathways of arachidonate metabolism. In addition to anti-inflammatory properties, Singh and Majumdar (1999) also reported O. sanctum-fixed oil had antiulcer activity. A recent study by Dharmani et al. (2004) confirmed the antiulcer and ulcer-healing properties of O. sanctum. Using acetic acid-induced chronic gastric-ulcer animal models, they found the ulcers were completely healed within 20 days of treatment. They attributed this effect to the cytoprotective properties of O. sanctum, which has considerable potential for treating peptic ulcers.
Using an anaesthetized dog, Singh et al. (2001) showed the oil from O. sanctum exhibited hypotensive and anticoagulant activities comparable to that of aspirin. The ability of the oil to increase the pentobarbitone-induced sleeping time in rats was attributed to its possible inhibition of the cytochrome system involved in the hepatic metabolism of this drug.
The potential of O. sanctum for treating diabetes mellitus was examined by Vats and coworkers (2002), using an ethanolic extract from its leaves. They found a small but significant hypoglycemic effect in normal rats, as a single administration of 100, 200, and 400 mg/kg of the extract decreased glucose levels by 7.64 percent, 17.18 percent, and 19.78 percent, respectively. A significant reduction in plasma glucose levels was also observed in alloxanized rats. Recent work by Vats et al. (2004) showed O. sanctum significantly increased the activity of glucokinase, hexokinase, and phospho-fructokinase, the three key enzymes of carbohydrate metabolism, in streptozotocin-induced rats. The increase in these glycolytic enzymes observed in animals treated with O. sanctum could be secondary to the release of insulin. Since streptozotocin diabetes is an insulin-deficient model, it is likely that the component in O. sanctum exerts insulinomimetic activity. Further clinical studies are needed, however, to more conclusively establish O. sanctum as an antidiabetic herb. An earlier in vitro study by Halder et al. (2003) showed that the anticataract properties of an aqueous extract from O. sanctum was a significant inhibitor of aldose reductase in the rat lens. The latter enzyme plays a key role in sugar-induced cataract formation.
References
Bhargava, K.P. and Singh, N., Antistress activity of Ocimum sanctum Linn, Ind. J. Med. Res., 73:443–451, 1981.
Dharmani, P., Kuchibhotla, V.K., Maurya, R., Srivastava, S., Sharma, S., and Palit, G., Evaluation of antiulcerogenic and ulcer-healing properties of Ocimum sanctum Linn, J. Ethnopharmacol., 99:361–366, 2004.
Godhwani, S., Godhwani, J.L., and Was, D.S., Ocimum sanctum—an experimental study evaluating its anti-inflammatory, analgesic and antipyretic activity in animals, J. Ethnopharmacol., 21:153–163, 1987.
Godhwani, S., Godhwani, J.L., and Vyas, D.S., Ocimum sanctum—a preliminary study evaluating its immunoregulatory profile in albino rats, J. Ethnopharmacol., 24:193–198, 1998.
Halder, N., Joshi, S., and Gupta, S.K., Lens aldose reductase inhibiting potential of some indigenous plants, J. Ethnopharmacol., 86:113–116, 2003.
Singh, S. and Majumdar, D.K., Evaluation of antiinflammatory activity of fatty acids of Ocimum sanctum fixed oil, Ind. J. Exp. Biol., 35:380–383, 1997.
Singh, S. and Majumdar, D.K., Evaluation of the gastric antiulcer activity of fixed oil of Ocimum sanctum (Holy Basil), J. Ethnopharmacol., 65:13–19, 1999.
Singh, S., Majumdar, D.K., and Rehan, H.M.S., Evaluation of anti-inflammatory potential of fixed oil of O. sanctum and its possible mechanism of action, J. Ethnopharmacol., 54:19–26, 1996.
Singh, S., Rehan, H.M.S., and Majumdar, D.K., Effect of Ocimum sanctum fixed oil on blood pressure, blood clotting time and pentobarbitone-induced sleeping time, J. Ethnopharmacol., 78:139–143, 2001.
Vats, V., Grover, J.K., and Rathi, S.S., Evaluation of anti-hyperglycemic and hypoglycemic effect of Trigonella foenum-graecum Lnn, Ocimum sanctum Linn and Pterocarpus marsupium Linn in normal and alloxanized diabetic rats, J. Ethnopharmacol., 79: 95–100, 2002.
Vats, V., Yadav, S.P., and Grover, J.K., Ethanolic extract of Ocimum sanctum leaves partially attenuates stroptozotocin-induced alterations in glycogen content and carbohydrate metabolism in rats. J. Ethnopharmacol., 90:155–160, 2004.
Oleuropein
Oleuropein is a polyphenolic glycoside constituent in the leaves, fruit, and oil of olives (Olea europaea) responsible for the bitter taste of olives (Panizzi et al., 1960). Its ability to inhibit platelet aggregation induced by arachidonic acid and adenosine diphosphate was first reported by Petroni et al. (1995). The effect of Oleuropein on the platelet-activating factor (PAF), the third and most potent pathway causing platelet aggregation, was investigated by Andrikopoulos and coworkers (2002). Addition of 10 μM oleuropein, a level equivalent to the average intake of olive oil or olive pieces in the Mediterranean diet, reduced in vitro oxidation of LDL cholesterol by total polar compounds formed during oil frying by approximately 50 percent. Oleuropein also inhibited human-plasma aggregation irrespective of its induction by arachidonic acid, adenosine diphosphate, or PAF. These results suggested oleuropein could play a role in the prevention of atherogenic plaques and thus reduce the risk for cardiovascular disease. The first experimental evidence for the direct cardioprotective effect of oleuropein following coronary occlusion was reported recently by Manna and coworkers (2004). The antioxidant properties of oleuropein appeared to prevent postischemic oxidative burst by reducing the amount of oxidized glutathione, a sensitive marker of the heart’s exposure to oxidative stress. The presence of oleuropein also reduced lipid-membrane peroxidation by reducing thiobarbituricacid reactive substances in cardiac tissue after ischemia/reperfusion of isolated rat hearts (Figure O.70).
Oleuropein. (From Furneri et al., Int. J. Antimicrob. Agents, 20:293– 296, 2002. With permission.)
Oleuropein also inhibited or delayed the growth of a number of bacteria and microfungi (Tranter et al., 1993; Capasso et al., 1995; Tassou et al., 1995). Bisignano et al. (1999) reported oleuropein exhibited antimicrobial activity against the human pathogenic bacteria ATTC and clinically isolated Gram-positive and Gram-negative strains of Salmonella spp., Vibrio spp., and Staphylococcus aureus. Further work by Furneri et al. (2002) confirmed the in vitro antimycoplasmal activity of oleuropein by its inhibition of Mycoplasma fermentans and Microplasma hominis strains. The latter are normally resistant to erythromycin and very often to tetracyclines. However, further research is needed to determine whether oleuropein retains its antimycoplasmal properties in vivo.
>FIGURE O.70 Effect of oleuropein (OE) on thiobarbituric-reactive substance (TBARS) formation in the cardiac tissue after ischemia/reperfusion of isolated rat hearts. Isolated hearts were subjected to 30 min of global ischemia and then reperfused. After 1 h of reperfusion, hearts were removed from the perfusion apparatus and TBARS measured. Data (mean±SD; n=6) were analyzed by the Student t test. *p<0.05 compared to SHAM samples. (Manna et al., J. Nutr. Biochem., 15:461–466, 2004. With permission.)
References
Andrikopoulos, N.K., Antonopoulou, S., and Kaliora, A.C., Oleuropein inhibits LDL oxidation induced by cooking oil frying by-products and platelet aggregation induced by plateletactivating factor, Lebensm-Wiss u-Technol., 35:479–484, 2002.
Bisignano, G., Tomaino, A., Lo Cascio, R., Crisafi, G., Uccella, N., and Saija, A., On the in-vitro antimicrobial activity of oleuropein and hydroxytyrosol, J. Pharm. Pharmacol., 51:253–259, 1999.
Capasso, R., Evidente, A., Schivo, L., Orru, G., Marcialis, M.A., and Cristinzio, G., Antibacterial polyphenols from olive oil mill waste waters, J. Appl. Bacterial, 79:393–398, 1995.
Furneri, P.M., Marino, A., Saija, A., Uccella, N., and Bisignano, G., In vitro antimycoplasmal activity of oleuropein, Int. J. Antimicrob. Agents, 20:293–296, 2002.
Manna, C., Migliardi, V., Golino, P., Scognamiglio, A., Galletti, P., Chiariello, M., and Zappia, V., Oleuropein prevents oxidative myocardial injury induced by ischemia and reperfusion, J. Nutr. Biochem., 15:461–466, 2004.
Panizzi, A., Scarpati, M.L., and Oriente, G., Chemical structure of oleuropein, bitter glycoside of olive with hypotensive activity, Gaz. Chim. Ital., 90:1449–1485, 1960.
Petroni, A., Blasevich, M., Salami, M., Papini, N., Montedoro, G.F., and Galli, C., Inhibition of platelet aggregation and eicosanoid production by phenolic components of olive oil, Thrombosis Res., 78:151–160, 1995.
Tassou, C.C. and Nychas, G.J.E., Inhibition of Salmonella enteridis by oleuropein in broth and in a model system, Lett. Appl. Microbiol., 20:120–124, 1995.
Tranter, H.S., Tassou, C.C., and Nychas, G.J.E., The effect of the olive phenolic compound, oleuropin, on growth and enterotoxin B production by Staphylococcus aureus, J. Appl. Bact., 74:253–259, 1995.
Oligofructose
see also Inulin, Prebiotics Oligofructose, a nondigestible carbohydrate composed of fructose units, including inulin, provide a number of benefits, such as constipation relief (Den Hond et al., 2000), prebiotics (Gibson et al, 1995), stimulation of calcium absorption from food (Van den Heuvel et al., 1999), and cancer prevention (Taper et al., 1998; Reddy et al., 1997).
The prebiotic nature of Oligofructose was demonstrated by Rao (2001), who fed eight healthy subjects 5 g/day of Oligofructose over three weeks compared to an equivalent amount of sucrose. Consumption of this low dose of oligosaccharides caused a one-log cycle increase in bifidobacterium after 11 days, indicative of an improved fecal-bacteria composition. A quantitative approach by Vulevic et al. (2004) derived an equation for measuring the prebiotic effect (MPE) of dietary fructooligosaccharides that included the production of lactic acid, as well as short-chain fatty acids (SCFA), acetic, proprionic, and butyric acids. The production of SCFA, such as the proprionate/acetate ratios, was reported to affect plasma glucose and lipid metabolism (Todesco et al., 1991; Boillot et al., 1995). Giacco and coworkers (2004) found that a moderate intake of short-chain fructooligosaccharides (10.6 g/day) by subjects with mild hypercholesterolemia, had no clinically relevant effect on either glucose or cholesterol levels, both at fasting or in the postprandial period. However, a small but significant increase was observed for Lp(a) levels, together with a reduction in postprandial insulin response.
Kelly-Quagliana and coworkers (2003) found that Oligofructose and inulin both modulated immune function in mice by increasing the level of natural killer (NK) cell activity of splenocytes and phagocytic activity of peritoneal macrophages. Both upregulated the macrophage-dependent immune responses in a dose-dependent manner.
References
Boillot, J., Alamowitch, C., and Berger, A.M., Effects of dietary proprionate on hepatic glucose production, whole-body glucose utilization, carbohydrate and lipid metabolism in normal rats, Br. J. Nutr., 73:241–251, 1995.
Den Hond, E., Geypens, B., and Ghoos, Y., Effects of long chain chicory inulin on constipation, Nutr. Res., 20:731–736, 2000.
Giacco, R., Clemente, G., Luongo, D., Lasorella, G., Fiume, I., Brouns, F., Bornet, F., Patti, L., Cipriano, P., Rivellese, A.A., and Riccardi, G., Effects of shortchain fructo-oligosaccharides on glucose and lipid metabolism in mild hypercholesterolaemic individuals, Clin. Nutr., 23:331– 340, 2004.
Gibson, G.R., Beatty, E.R., Wang, X., and Cummings, J.H., Selective stimulation of bifidobacteria in the human colon by Oligofructose and insulin, Gasteroenterol., 108:975–982, 1995.
Kelly-Quagliana, K.A., Nelson, P.D., and Buddington, R.K., Dietary Oligofructose and inulin modulate immune functions in mice, Nutr. Res., 23:257–267, 2003.
Rao, V.A., The prebiotic properties of Oligofructose at low intake levels, Nutr. Res., 21:843–848, 2001.
Reddy, B.S., Hamid, R., and Rao, C.V., Effect of dietary Oligofructose and inulin on colonic preneoplastic aberrant crypt foci inhibition, Carcinogenesis, 18:1371–1374, 1997.
Taper, H.S., Lemort, C., and Roberfroid, M.B., Inhibitory effect of dietary inulin and Oligofructose on the growth of transplantable mouse tumor, Anticancer Res., 18:4123–4126, 1998.
Todesco, T., Rao, A.V., Bosello, A., and Jenkins, D.J.A., Proprionate lowers blood glucose and alters lipid metabolism in healthy subjects, Am. J. Clin. Nutr., 54:860–865, 1991.
van den Heuvel, E.G.H., Muys, Th., van Dokkum, W., and Schaafsma, G., Oligofructose stimulates calcium absorption in adolescents, Am. J. Clin. Nutr., 69:544–548, 1999.
Vulevic, J., Rastall, R.A., and Gibson, G.R., Developing a quantitative approach for determining the in vitro prebiotic potential of dietary oligosaccharides, FEMS Microbiol. Lett., 236:153–159, 2004.
Oligosaccharides
see Oligofructose and Inulin
Olives
see also Hydroxytyrosol and Oleuropein Olives are oval fruits composed of water, oil, sugar, protein, organic acids, and cellulose. The oil, which accounts for around 20 percent of the olive, is located mainly in the pulp. In addition to being a rich source of the monounsaturated fatty acid oleic acid, olives also contain large amounts of polyphenols, of which the secoiridoid glycoside oleuropein is the most abundant. The latter is composed of elenolic acid (oleoside-11-methylester) and hydroxytyrosol (3,4-dihydroxyphenyl ethanol) (Blekas et al., 2002). Oleuropein is responsible for the very bitter taste of unprocessed olives and is normally eliminated prior to human consumption by lye treatment or fermentation. Nevertheless, oleuropein has been shown to enhance nitric-oxide production in mouse macrophages, considered beneficial for the protection of the organism (Visioli et al. 1998). During ripening, oleuropein is hydrolyzed to smaller molecules, such as hydroxytyrosol, which gives extra-virgin oil its rich and complex flavor. Other phenolics reported in unprocessed olives include ligstroside (ester of elenolic acid with 4-hydroxyphenyl ethanol or tyrosol) and hydroxycinnamic acids, caffeic and ferulic.
The beneficial effects of olive oil are not only due the presence of monounsaturated fatty acids but also to the antioxidant properties of polyphenols in the oil. Hydroxytyrosol (3,4-dihydroxyphenyl) ethanol (DHPE), which accounts for 70–80 percent of total phenols in extra-virgin olive oil, was shown to be a very effective scavenger of peroxy radicals, protecting human erythrocytes from oxidative damage (Manna et al., 1998). In addition to tyrosol and hydroxytyrosol, Bonoli et al. (2003) identified a number of other phenolic compounds in olive oil by capillary-zone electrophoresis, including 2,3-dihydroxyphenylethanol. The lower incidence of cardiovascular disease was attributed to their contribution in the Mediterranean diet. Olive polyphenols have also been associated with a lower incidence of some cancers (Trichopoulou, 1995; Trichopoulou et al., 2000). Visioli and Galli (2003) recently reviewed the waste products of olives as sources of bioactive compounds for the treatment of chronic diseases.
References
Blekas, G., Vassilakis, C., Harizanis, C., Tsimidou, M., and Boskou, D.G., Biophenols in table olives, J. Agric. Food Chem., 50:3688–3692, 2002.
Bonoli, M., Montanucci, M., Toschi, T.G., and Lerker, G., Fat separation and determination of tyrosol, hydroxytyrosol and other phenolic compounds in extra-virgin olive oil by capillary zone electrophoresis with ultraviolet-diode array detection, J. Chromatogr. A, 1011:163–172, 2003.
Manna, C., Galled, P., Cucciolla, V., Montedoro, G., and Zappia, V., Olive oil hydroxytyrosol protects human erythrocytes against oxidative damages, J. Nutr. Biochem., 10:159–169, 1999.
Trichopoulou, A., Olive oil and breast cancer, Cancer Causes Contrl., 6:475–476, 1995.
Trichopoulou, A., Lagiou, P., Kuper, H., and Trichopoulos, D., Cancer and Mediterranean dietary traditions, Cancer Epidemiol. Biomarkers Prev., 9:869–873, 2000.
Visioli, F., Bellosta, S., and Galli, C., Oleuropein, the bitter principle of olives, enhances nitric oxide production by mouse macrophages, Life Sci., 62: 541–546, 1998.
Visioli, F. and Galli, C., Olives and their production waste products as sources of bioactive compounds, Curr. Topics Nutraceutical Res., 1:85–88, 2003.
Omega-3 fatty acids
see also Eicosapentaenoic and Docosahexaenoic acids Omega3 fatty acids belong to the family of long-chain polyunsaturated fatty acids with the first double bond located at the third carbon from the terminal methyl end of the molecule between carbons three and four. They are the precursors of prostaglandins, thromboxanes, and leukotrienes, chemical messengers that control a number of important biochemical processes, including cell growth and division, blood pressure and clotting, immune reactions, and inflammation. The essential fatty acid, α-linolenic acid (C18:3ω3), is the precursor of eicosapentaenoic acid (EPA) (C20:5 ω-3) and docosahexaenoic acid (DHA) (C22:6 ω-3). It has been suggested that 1.5 percent of the daily total calories should be derived from omega-3 fatty acids (3 g for men and 2 g for women) or EPA and DHA (1.4 g for men and 1.2 g for women). The richest sources of omega-3 are fish oils, such as herring, mackerel, sardines, and salmon (Eskin, 2002). To meet these levels requires eating three (200–300 g) portions per week of these fatty fish. Increasing omega-3 intake is important for individuals with a family history of heart or circulatory problems. Omega-3 fatty acids reduce the risk of heart attacks by reestablishing a more normal lipid profile among people with hypertriglyceridemia. Eritsland et al. (1995) reported a 19 percent reduction in triglyceride levels when fed 4 g of fish. Epidemiological studies suggest that in societies where diets are high in fish, heart attacks, strokes, and circulatory problems are relatively rare. A 20-year study in the Netherlands by Simon (1994) showed that men who ate 30 g of fish daily were half as likely to die from coronary heart disease. Lau et al. (1993) also found that treating rheumatoid arthritis sufferers with supplements containing EPA (171 mg) and DHA (114 mg) reduced the amount of nonsteroidal, anti-inflammatory drugs (NSAIDs) needed. A marked improvement was observed after a year, in which there was a significant reduction in tender-joint counts and morning stiffness compared to the control group. This was confirmed in a later study by Kremer et al. (1995). The level of interleukin1 β decreased significantly in patients consuming fish oils, suggesting omega-3 fatty acids reduced the underlying disease process. Other areas in which omega-3 fatty acids appear to play a beneficial role include possible protection to smokers against chronic obstructive pulmonary disease (COPD). Britton (1995) postulated that omega-3 fatty acids reduce prostaglandin and leukotriene synthesis, inhibit migration of proinflammatory neutrophils into the lung, and reduce the lung’s response to allergens. The importance of omega-3 fatty acids in the synthesis of prostaglandins and other inflammatory mediators led to their role in other inflammatory disease. For example, fish oils have been shown to lessen itching and inflammation in psoriasis, while essential fatty acids exert anti-inflammatory action in infantile seborrheic dermatisis and diaper dermatitis. A recent application is the possible use of omega-3 fatty acids for reducing the relapse in the inflammatory disease of the GI tract, Crohn’s disease.
Epidemiological and experimental evidence suggests that omega-3 fatty acids exert a protective effect against common cancers, most notably breast and colon (Rose and Connolly, 1999; Klein et al., 2000; Maillard et al., 2002). Animal studies provided convincing evidence that omega-3 fatty acids inhibited mammary-tumor growth and metastasis. Hardman (2002) reviewed the evidence for omega-3 fatty acids as an anticancer agent, suggesting it may augment cancer therapy. Kato and coworkers (2002) showed dietary omega-3 fatty acids exerted significant tumorsuppressing activities on the growth of human colon carcinoma xenograft in athymic nude mice. The primary tumor-suppressing acid was found to be docosahexaenoic acid.
References
Britton, J., Dietary fish oil and airways obstruction, Thorax., 50 (Suppl. 1): s11–s15, 1995.
Eristland, I., Arnesen, H., Seljefolt, I. and Hostmark, A.T., Long-term metabolic effects of n-3 polyunsaturated fatty acids in patients with coronary heart disease, Am. J. Clin. Nutr., 61:831– 836, 1995.
Eskin, N.A.M., Authentication of borage, evening primrose and fish oils, in Authentication of Fats and Oils, Jee, T., Ed., CRC Press, U.S.A., and Blackman Pub., U.K., 2002, pp. 95–114.
Hardman, W.E., Omega-3 fatty acids to augment cancer therapy, J. Nutr., 132:3508–3512, 2002.
Kato, T., Hancock, R.L., Mohammadpour, H., McGregor, B., Manalo, P., Khaiboullina, S., Hall, M.R., Pardini, L., and Pardini, R.S., Influence of omega-3 fatty acids on the growth of human colon carcinoma in nude mice, Cancer Lett., 187:169–177, 2002.
Klein, V., Chajes, V., Germain, E., Schulgen, G., Pinault, M., Malvy, D., Lefrancq, T., Fignon, A., Le Floch, O., Lhuillery, C., and Bognoux, P., Low alpha linolenic acid content of adipose tissue is associated with an increased risk of breast cancer, Eur. J. Cancer, 36:335–340, 2000.
Kremer, J.M., Lawrence, D.A., Petrillo, G.F., Litts, L.L., Mullaly, P.M., Rynes, R.I., Stocker, R.P., Parhami, N., Greenstein, N.S., and Fuchs, B.R., Effects of high-dose fish oil on rheumatoid arthritis after stopping nonsteroidal anti-inflammatory drugs: Clinical and immune correlates, Arthritis Rheum., 38: 1107–1114, 1995.
Lau, C.S., Morley, K.D., and Belch, J.J., Effects of fish oil supplementation on non-steroidal antiinflammatory drug requirement in patients with mild rheumatoid arthritis—a double blind placebo controlled study, Br. J. Rheumatol., 32:982–989, 1993.
Maillard, V., Bougnoux, P. Ferrari, P., Jourdan, M-L., Pinault, M., Lavillonniere, F., Body, G., Le Floch, O., and Chajes, V., N-3 and N-6 fatty acids in breast adipose tissue and relative risk of breast cancer in a case control study in Tours, France, Int. J. Cancer, 98:78–83, 2002.
Rose, D.P. and Connolly, J.M., Omega-3 fatty acids as cancer chemopreventative agents, Pharmacol. Ther., 83:217–244, 1999.
Simon, H.B., Patient-directed, non-prescription approaches to cardiovascular disease, Arch. Int. Med., 154:2283–2296, 1994.
Onions (Allium cepa Liliacae)
Onions are one of the major sources of flavonoids in the Western diet (Knekt et al., 1996). They are particularly rich in quercetin, and its glycosides have been used in traditional medicine for their antiasthmatic, antithrombotic, antihypertensive, antihyperglycemic, antihyperlipidemic, and antitumor properties (Bordia et al., 1975, 1977; Belman, 1983; Dorsch et al., 1985; Kleijnen et al., 1990; Wagner et al., 1990). These health benefits are attributed to the presence of flavonoids and alk(en)yl cysteine sulphoxides in onions (Griffiths et al., 2002).
In vitro studies by Glasser et al. (2002) showed quercetin, a flavonoid in onion, inhibited hepatic cholesterol biosynthesis. Kumari and Augusti (2002) found (+)-S-methyl-L-cysteine sulfoxide in onion exhibited antidiabetic and antioxidant activities comparable to standard drugs. However, Ali and coworkers (2000) found onion extracts ineffective in lowering serum cholesterol in rabbits kept on a cholesterol-supplemented diet compared to garlic.
The presence of quercetin, alkyl sulfides, and diallyl disulfide in onions suggested it had strong anticancer properties. Seki et al. (2000) found that both onions and garlic equally suppressed the growth of leukemia HL-60 cells. Hu and coworkers (1999) reported an inverse relationship between onions in the diet and the risk of brain cancer. Shon and coworkers (2004) found the antioxidant and antimutagenic activities of ethyl-acetate extracts from red, yellow, and white onion extracts could be attributed to the presence of phenols and flavonoids.
References
Ali, M., Thomson, M., and Afzal, M., Garlic and onions: Their effect on eicosanoid mretabolism and its clinical relevance, Prost. Leuk. Essent. Fatty Acids, 62:55–73, 2000.
Belman, S., Onion and garlic oils inhibit tumor promotion, Carcinogenesis, 4:1063–1065, 1983.
Bordia, A., Bansal, H.C., Arora, S.K., and Singh, S.V., Effect of essential oils of garlic and onion on alimentary hyperlipemia, Atherosclerosis, 21:15–19, 1975.
Bordia, A., Verma, S.K., Vyas, A.K., Khabya, B.L., Rathore, A.S., Bhu, N., and Bedi, H.K., Effect of essential oil of onion and garlic on experimental atherosclerosis in rabbits, Atherosclerosis, 26:379–386, 1977.
Dorsch, W.V., W., Adam, H.O., Weber, J., and Ziegeltrum, T., Antiasthmatic effects of onion extracts—detection of benzyl- and other isothiocyanates (mustard oils) as antiasthmatic compounds of plant origin, Eur. J. Pharmacol., 107:17–24, 1984.
Glasser, G., Graefe, E.U., Struck, F., Veit, M., and Gebhardt, R., Comparison of antioxidative capacities and inhibitory effects on cholesterol biosynthesis of quercetin and potential metabolites, Phytomedicine, 9:33–40, 2002.
Griffiths, G., Trueman, L., Crowther, T., Thomas, B., and Smith, B., Onions—a global benefit to health, Phytother. Res., 16:603–615, 2002.
Hu, J., La Vecchia, C., Nigri, E., Chatenoid, L., Bosetti, C., Jia, X., Liu, R., Huang, G., Bi, D., and Wang, C., Diet and brain cancer in adults: a case controlled study in Northeat China, Inst. J. Cancer, 81:2–23, 1999.
Kleijnen, J., Knipschild, P., and Terriet, G., Garlic, onions and cardiovascular risk factors: A review of the evidence from human experiments with emphasis on commercially available preparations, Br. J. Clin. Pharmacol., 28:535–544, 1989.
Knekt, P., Jarvinen, R., Reunanen, A., and Maatela, J., Flavonoid intake and coronary mortality in Finland: A cohort study, Br. Med. J., 312:478–481, 1996.
Kumari, K. and Augusti, K.T., Antidiabetic and antioxidant effects of S-methyl cysteine sulfoxide from onions (Allium cepa Linn) as compared to standard drugs in alloxan diabetic rats, Ind. J. Exp. Biol., 40: 1005–1009, 2002.
Seki, T., Tsuji, K., Hayato, Y., Moritomo, T., and Ariga, T., Garlic and onion oils inhibit proliferation and induce proliferation and induce differentiation of HL60 cells, Cancer Lett., 160:29–35, 2000.
Shon. M.-Y., Choi, S.-D., Kahng, G.-G., Nam, S.-H., and Sung, N.-J., Antimutagenic, antioxidant and free radical scavenging activity of ethyl acetate extracts from white, yellow and red onions, Food Chem. Toxicol., 42:659–666, 2004.
Thomson, M., Alnaqeeb, M.A., Bordia, T., Al-Hassan, J., Afzal, M., and Ali, M., Effects of aqueous extract of onion on the liver and lung of rats, J. Ethnopharmacol., 61:91–99, 1998.
Wagner, H., Dorsch, W., Bayer, Th., Breu, W., and Wilier, F., Antiasthmatic effects of onions: Inhibition of 5-lipoxygenase and cyclooxygenase in vitro by thiosulfinates and cepaenes, Prostagland. Leuk. Essent. Fatty Acids, 39:59–62, 1990.
Oolong tea (Camelia sinensis)
Oolong tea, one of three types of tea manufactured from tea leaves, is considered a functional food because of its antioxidant, hypocholesterolemic, and antiobesity properties (Yang and Koo, 1997; Benzie and Szeto, 1999; Han et al, 1999). It is produced from green tea by heating and fermentation and contains more than 70 different compounds, such as oolonghomobisflavan A, B1, and theasinensin, formed from epigallocatechin gallate. Mihara and coworkers (2004) recently identified a novel acylated quercetin tetraglycoside in oolong tea extracts, 3-O-(2G-p-coumaroyl-3G-O-β-L-arabinosyl- 3R-O-D-glucosylrutinoside (compound 1). These researchers also found that compound 1 was a good antioxidant but not quite as strong as quercetin (Table O.50). Unlike quercetin, the acylated quercetin tetraglycoside (compound 1) was soluble in water, which suggested it might be a better antioxidant, as it would be absorbed more easily.
Yang and coworkers (2001) compared green-, oolong-, and black-tea extracts for their ability to modulate lipid metabolism in hyperlipidemia rats maintained on a high-sucrose diet. Oolong tea reduced food intake, while both oolong and black teas significantly decreased body weight gain and food efficiency. Although green and oolong teas had similar catechins, green tea still exerted a greater antihyperlipidemic effect. Kuihara et al. (2002) showed oolong tea alleviated the stress-induced decrease in the rate of blood-lipid metabolism in mice. Reduction in plasmatriacylglycerol levels by oolong tea in the stressed mice was attributed to the antistress and antioxidant properties of its polyphenols and saponins, theasaponins E1 and E2 (Okuda and Han, 2001).
TABLE O.50 Antioxidant Activity of Compound 1
Compound 1. (From Mihara et al., Tetrahedron Lett., 45:5077–5080, 2004. With permission.)
Shimada et al. (2004) demonstrated, for the first time, that long-term intake of oolong tea (one month) significantly (p<0.05) increased plasma adiponectin levels from 6.26±3.26 μg/mL to 6.88 ± 3.28 μg/mL in patients suffering from coronary artery disease. Adiponectin, a collagen-like plasma protein produced by adipose tissue normally abundant in circulation, is reduced in patients suffering from obesity, type 2 diabetes mellitus, and coronary artery disease (Matsuzawa et al., 1999; Ouchi et al., 1999; Hotta et al., 2000). A significant (p< 0.01) increase in LDL particle-size plasma levels from 25.02±0.67 nm to 25.31±0.60 nm was also observed. These effects could slow down the progression of atherosclerosis, as plasmalevel LDL particle sizes were shown previously to be lower in patients with coronary artery disease and associated with the etiology of the disease (Lamarche et al., 1998).
References
Benzie, I.F.F. and Szeto, Y.T., Total antioxidant capacity of teas by the ferric reducing/antioxidant power assay, J. Agric. Food Chem., 47:633–636, 1999.
Han, L.K., Takaku, T., Li, J., Kimura, Y., and Okuda, H., Anti-obesity action of Oolong tea, Int. J. Obes. Real. Metab. Disord., 23:98–115, 1999.
Hotta, K., Funahashi, T., and Arita, Y., et al., Plasma concentrations of a novel, adipose-specific protein, adiponectin, in type 2 diabetic patients, Arterioscler. Thromb. Vasc. Biol., 20:1595– 1599, 2000.
Kurihara, H., Fukami, H., Koda, H., Tsuruoka, N., Suguira, N., Shibata, H., and Tanaka, T., Effects of oolong tea on metabolism of plasma fat in mice under restraint stress, Biosci. Biotechnol. Biochem., 66:1955–1958, 2002.
Lamarche, B., Tchernof, A., and Mauriege, P., Fasting insulin and apolipoprotein B levels and low-density lipoprotein particle size as risk factors for ischemic heart disease, JAMA, 279:1955– 1961, 1998.
Matsuzawa, Y., Funahashi, T., and Nakamura, T., Molecular mechanism of metabolic syndrome X: Contribution of adipocytokines adipocyte-derived bioactive substances, Ann. N.Y. Acad. Sci., 892:146–154, 1999.
Mihara, R., Mitsunaga, T., Fukui, Y., Nakai, M., Yamaji, N., and Shibata, H., A novel acylated quercetin tetraglycoside from oolong tea (Camelia sinensis) extracts, Tetrahedron Lett., 45:5077–5080, 2004.
Okuda, H. and Han, L.K., Medicinal plant and its related metabolic modulators, Nippon Yakurigaku Zasshi, 118:347–352, 2001.
Ouchi, N., Kihara, S., Arita, Y., et al., Novel modulator for endothelial adhesion molecules: Adipocytederived plasma protein adiponectin, Circulation, 100:2473–2476, 1999.
Shimada, K., Kawarabayashi, T., Tanaka, A., Fukuda, D., Nakamura, Y., Yoshiyama, M., Takeuchi, K., Sawaki, T., Hosoda, K., and Yoshikawa, J., Oolong tea increases plasma adiponectin levels and low-density lipoprotein particle size in patients with coronary artery disease, Diab. Res. Clin. Practice, 65:227–234, 2004.
Yang, M.-H., Wang, C.-H., and Chen, H.-L., Green, oolong and black tea extracts modulate lipid metabolism in hyperlipidemia rats fed high-sucrose diet, J. Nutr. Biochem., 12:14–20, 2001.
Yang, T.T. and Koo, M.W.L., Hypercholesterolemic effects of Chinese tea, Pharmacol. Res., 35:505–512, 1997.
Oranges
see Orange Juice
Orange juice
see also Hesperidin, Nobiletin, and Tangeretin Besides being an excellent source of provitamin A carotenoids, orange juice is rich in antioxidant carotenoids. Many of these carotenoids appear to play a role in the reduction of degenerative diseases, such as cancer and heart disease. These include β-carotene, α-carotene, and β-cryptoxanthin, as well as zeaxanthin and lutein. Using the 2,2-diphenyl1-picrylhydrazyl stable radical-scavenging method, Sanchez-Moreno et al. (2003) found vitamin C was the largest contributor to the antioxidant potential of orange juice, followed by flavonoids and carotenoids.
TABLE O.51 Effect of Orange Juice on Plasma Lipids
The hypocholesterolemic effect of soybean was attributed to the flavonoid genistein (Anthony et al., 1996). The similarity in structure between genistein and hesperetin in oranges may also make orange juice hypocholesterolemic. This was confirmed by Kurowska and coworkers (2000), who showed a daily minimum consumption of 750 mL of orange juice by hypercholesterolemic individuals significantly increased HDL-cholesterol concentrations by 21 percent and the LDL-HDL cholesterol ratio by 16 percent. No change was observed for LDL-cholesterol and homocysteine levels, while triacylglycerol levels increased 30 percent from 1.6 to 2.0 mmol/L (Table O.51).
Ikegawa et al. (2000) also demonstrated the ability of orange-juice components to inhibit P-glycoprotein in adriamiacyin-resistant human myelogenous leukemia (K562/ADM) cells. P-glycoprotein acts as an energy-dependent drug efflux pump, decreasing the intracellular drug accumulation and the therapeutic effect of many chemotherapeutic agents. All three orange-juice components, tangeretin, nobiletin, and heptamethoxyflavone (HMF), were found to reverse the multidrug resistance (MDR) without inhibiting CYP-3A4.
Sprecher and coworkers (2002) reported a positive effect of dietary intervention of not-from-concentrate orange juice to 24 nondiabetic patients with angiographic CAD on vascular regulation, which could affect health strategies for reducing blood pressure. A study by Lilja and coworkers (2004) noted that orange juice reduced the bioavailability of celiprolol, a β-adrenergic-blocking agent with vasodilating properties. The negative impact of orange juice with celiprolol must be avoided by patients on this drug.
References
Anthony, M.S., Clarkson, T.B., Hughes, Ch., Jr., Morgan, T.M.. and Burke, C.L., Soybean isoflavones improve cardiovascular risk without affecting the reproductive system of prebuteral Rhesus monkeys, J. Nutr., 126:43–70, 1996.
de Ancos, B., Sgroppo, S., Plaza, L. and Cano, M.P., Possible nutritional and health-related value by highpressure treatment, J. Sci Food Agric., 82:790–792, 2002.
Ikegawa, T., Ushigome, F., Kobayu, N., Morimoto, S., Shoyama, Y., Naito, M., Tsuruo, T., Ohtani, H., and Sawada, Y., Inhibition of P-glycoprotein by orange juice components, polymemoxyflavones in adriamycin-resistant human myelegenous leukemia (K562/ADM) cells, Cancer Lett., 160:21–28, 2000.
Kurowska, E.M., Spence, J.D., Jordan, J., Wetmore, S., Freeman, D.J., Piche, L.A., and Serratore, P., HDL-cholesterol-raising effect of orange juice in subjects with hypercholesterolemia, Am. J. Clin. Nutr., 72:1095–1100, 2000.
Lilja, J.J., Juntti-Patinen, L., and Neuvonen, P.J., Orange juice substantially reduces the bioavailability of the β-adrenergic-blocking agent celiprolol, Clin. Pharmacol. Then, 75:184– 190, 2004.
Sanchez-Moreno, C., Plaza, L., de Ancos, B., and Cano, M.P., Quantitative bioactive compounds assessment and their relative contribution to theantioxidant capacity of commercial orange juices, J. Sci. Food Agric., 83:430–439, 2003.
Sprecher, D.L., Foody, J.M., Acevedo, M., Scafidi, K.M., Aronow, H., and Pearce, G.L., Dietary intervention with orange juice lowers blood pressure: Pilot study, JACC, 39:254–258, 2002.
Oregano (Origanum vulgare L.)
Or egano, an aromatic perennial herb, is a member of the Labiatae family. The oil from oregano is used for its fragrance in perfumes and for its flavor in seasonings. Health benefits associated with oregano have been attributed to antioxidants in its essential oil and soluble phenols (Engleberger et al., 1988; Peak et al., 1991; Eguchi et al., 1996). Kikuzaki and Nakatani (1988) identified rosmarinic acid as one of the major phenolic compounds in the methanolic extract of oregano leaves. The latter has been reported to exert both antioxidant and anti-inflammatory properties. The variability in the phenolic content of oregano, however, has limited it as a functional food. To overcome the problem of genetic heterogeneity of oregano, clonal selection has been used to ensure consistency in phenolic quantity and quality. Chun et al. (2005) compared a high phenolic clonal line of oregano developed at the University of Massachusetts with a purchased commercial heterogenous line. The clonal line was much higher in total phenolic s and antioxidant activity, as well as improved antimicrobial activity against Helicobacter pylori, an organism associated with ulcers. The development of high phenolic clonal oregano lines could provide useful functional-food sources of oregano for combating chronic bacterial infections.
References
Chun, S.-S., Vattem, D.A., Lin, Y.-T., and Shetty, K., Phenolic antioxidants from clonal oregano (Origanum vulgare) with antimicrobial activity against Helicobacter pylori, Process Biochem., 40:809–816, 2005.
Eguchi, Y., Curtis, O.F., and Shetty, K., Interaction of hyperhydricity-preventing Pseudomonas sp. with oregano (Origanum vulgare) and selection of high phenolics and rosmarinic acidproducing lines, Food Biotechnol., 10:191–202, 1996.
Engleberger, W., Hadding, U., Etschenber, E., Graf, E., Leyck, S., and Winkelmann, J., Rosmarinic acid. A new inhibitor of complement C3-covertase with anti-inflammatory activity, Int. J. Immunopharmacol., 10:721–737, 1988.
Kikuzaki, H. and Nakatani, N., Structure of a new antioxidative phenolic acid from oregano (Origanum vulgare L.), Agric. Biol. Chem., 53:519–524, 1988.
Peak, P.W., Pussel, B.A., Martyn, P., Timmermans, V., and Charles worth, J.A., The inhibitory effect of rosmarinic acid on complement involves the C5 convertase, Int. J. Immunopharmacol., 13:853–857, 1991.
γ-Oryzanol
γ-Oryzanol is a mixture of sterol esters of ferulic acid, found in rice-bran oil (Rogers et al., 1993).
The highest concentration of γ-oryzanol was recently extracted from the rice bran during the shorter milling duration (Rohrer and Siebenmorgen, 2004). Studies showed it lowered blood cholesterol in rats and that the addition of 0.5 percent γ-oryzanol to a cholesterolenriched diet effectively reduced triacylglycerols, LDL cholesterol, and VLDL cholesterol in the serum, and cholesterol in the liver (Nicolosi et al., 1993; Seetharamaiah and Chandrasekhara, 1993). In addition, γ-oryzanol was also an effective antioxidant, protecting ricebran oil from oxidation by iron or UV radiation (Jariwalla et al., 2001). Of the three major γ-oryzanol derivatives in rice bran, 24-methylenecycloartanyl ferulate exhibited the highest antioxidant activity compared to cycloartanyl ferulate or campestryl ferulate.
All three compounds were much stronger antioxidants than any of the vitamin E isomers (Xu et al., 2001). Earlier in vitro tests showed γ-oryzanol had superoxide dismutase-like antioxidant activity (Kim et al., 1995). A review by Cicero and Gaddi (2001) discusses some of the health claims made for γ-oryzanol, as well as the pharmacology and toxicology of rice-bran oil.
Three major γ-oryzanol derivatives in oats. (From Xu et al., 2001. With permission.)
References
Cicero, A.F.G. and Gaddi, A., Rice bran oil and γ-oryzanol in the treatment of hyperlipoproteinaemias and other conditions, Phytother. Res., 15:277–289, 2001.
Jariwalla, R.J., Rice-bran products: Phytonutrients with potential applications in preventive and clinical medicine, Drugs Under Exp. Clin. Res., 217:17–26, 2001.
Kim, S.J., Han, D., Moon, K.D., and Rhee, J.S., Measurement of superoxide-like activity of natural antioxidants, Biosci. Biotech. Biochem., 59:822–826, 1995.
Nicolosi, R.J., Rogers, E.J., Ausman, L.M., and Ormoefer, F.T., Rice bran oil and its health effects, in Rice Science and Technology, Marshall, W.E. and Wadsworth, J.I., Eds., Marcel Dekker, New York, 1993, pp. 421–437.
Rogers, E.J., Rice, S.M., Nicolosi, R.J., Carpenter, D.R., McClelland, C.A., and Romanczyk, L.R., Identification and quantitation of gamma-oryzanol components and simultaneous assessment of tocols in rice oil bran, J. Am. Oil Chem. Soc., 70:301–307, 1993.
Rohrer, C.A. and Siebenmorgen, T.J., Nutraceutical concentrations within the bran of various rice kernel thickness fractions, Biosyst. Eng., 88:453–460, 2004.
Seetharamaiah, G.S. and Chandrasekhara, N., Comparative hypocholesterolemic activities of oryzanol, curcumin and ferulic acid in rats, J. Food Sci. Technol., 30:249–252, 1993.
Xu, Z., Hua, N., and Godber, J.S., Antioxidant activity of tocopherols, tocotrienols, and γ-oryzanol components from rice bran against cholesterol oxidation accelerated by 2,2′-azobis(2- methylpropionamide) dihydrochloride, J. Agric. Food Chem., 49:2077–2081, 2001.
Ovakinin
Ovakinin (2–7) is a novel, antihypertensive peptide produced from ovalbumin by chymotryptic digestion (Matoba et al., 2000). Yamada and coworkers (2002) showed that replacing the C-terminal Phe residue with Tryp improved the antihypertensive activity of ovakinin.
References
Matoba, N., Usui, H., Fujita, H., and Yoshikawa, M., A novel anti-hypertensive peptide derived from ovalbumin induces nitric oxide-mediated vasorelaxation in an isolated SHR mesenteric artery, FEBS Lett., 452:181–184, 1999.
Yamada, Y., Matoba, N., Usui, H., and Onishi, K., Design of a highly potent anti-hypertensive peptide based on ovakinin (2–7), Biosci. Biotechnol. Biochem., 66:1213–1217, 2002.
Oyster mushroom (Pleurotus ostreatus)
Oyster mushroom is a wood-rotting fungus produced industrially for the food industry on lignocellulose substrates. A pilot study by Bobek and coworkers (1993) showed that oyster mushroms suppressed diet-induced hypercholesterolemia in rats. The mechanisms responsible were shown to be reduced cholesterol absorption and increased excretion of plasma cholesterol (Bobek et al., 1994), reduced activity of 3-hydroxy-3-methylglutaryl CoA reductase, a key enzyme in cholesterol biosynthesis (Bobek et al., 1995), and a reduction in the production and secretion of verylow-density lipoproteins (VLDL) in hypercholesterolemic rats (Bobek and Ozdin, 1996). Long-term feeding of 5 percent oyster mushrooms to rats by Bobek et al. (1998) significantly reduced serum (31–46 percent) and liver (25–30 percent) cholesterol during the eighth and 28 weeks of feeding. In addition to lowering VLDL, there was a decrease in conjugated dienes in erythrocytes and an increase in reduced glutathione in the liver, accompanied by enhanced catalase and glutathione-peroxidase activity during the last period of the study.
TABLE O.52 Inhibition of Sarcoma 180 or Hepatoma 22 Growth by POL
Wang et al. (2000), using a simple procedure, isolated a lectin (POL) from the freshfruiting bodies of the edible oyster mushroom (Pleurotus ostreatum) that exhibited strong antitumor activity. It proved to be a dimeric lectin composed of two subunits with molecular weights of 40 and 41 kDa, respectively. It was a potent inhibitor of sarcoma S-180 and hepatoma H-22 growth, as evident in Table O.52.
References
Bobek, P. and Galbavy, S., Hypocholesterolemic and antitherogenic effect of oyster mushroom (Pleurotus ostreatus) in rabbit, Nahrung, 43:339–342, 1999.
Bobek, P., Hromadova, M., and Ozdin, L., Oyster mushroom (Pleurotus ostreatus) reduces the activity of 3-hydroxy-3-methylglutaryl Co A reductase in rat liver microsomes, Experentia., 51:589–, 1995.
Bobek, P., Kuniak, L., and Ozdin, L., The mushroom Pleurotus ostreatus reduces secretion and accelerates the fractional turnover rate of very low density lipoproteins in rat, Ann. Nutr. Metab., 37:142–145, 1993.
Bobek, P., Ozdin, L, and Galbavy, S., Dose- and time-dependent hypocholesterolemic effect of oyster mushroom (Pleurotus ostreatus) in rats, Nutrition, 14:282–286, 1998.
Bobek, P. and Ozdin, L., Oyster mushroom (Pleurotus ostreatus) reduces the production and secretion of very-low-density lipoproteins in hypercholesterolemic rats, Z. Ernahrungswiss., 35:249, 1996.
Bobek, P., Ozdin, L., and Kuniak, L., Mechanism of hypocholesterolemic effect of oyster mushroom (Pleurotus ostreatus) in rats: Reduction of cholesterol absorption and increase of plasma cholesterol removal, Z. Ernahrungswiss., 33:44–50, 1994.
Wang, H., Gao, J., and Ng, T.B., A new lectin with highly potent antihepatoma and antisarcoma activities from the oyster mushroom Pleurotus ostreatus, Biochem. Biophys. Res. Commun., 275:810–816, 2000.