Health Benefits of SoybeanIsoflavonoids and Related

Phenolic

• Soybeans are a well-known dietary staple of Asian countries such as Japan and are now consumed worldwide.

• Soybeans cannot be eaten raw, because they contain trypsin inhibitors, which can disrupt digestion activities in the stomach, leading to cramping and associated discomfort.

• Soybeans are usually fermented to produce distinct cultural or ethnic foods or food ingredients.

• East Asian populations that regularly consume soybeans as a part of their dietary intake seem to have lower incidences of cancers and oxidation linked diseases of old age than are prevalent in Western populations.

• The Japanese are estimated to consume 25–100 mg of

isoflavonoids per day. Chinese women are estimated to consume 39 mg of isoflavonoids per day.

• The consumption of isoflavonoids in Western diets is much lower, at less than 1 mg/day in the U.S. and U.K.

• Numerous epidemiological studies have demonstrated an association between the consumption of soybeans and improved health, particularly as a reduced risk for cancers or diseases, such as breast cancer, cardiovascular disease, and atherosclerosis.

• Consumption of soy foods has also been associated with a reduced risk of prostate cancer.

• Although soybean protein was first suspected to potentiate the health-promoting benefits of soybean consumption, these properties have more recently been linked to the biological activities of a specific group of phenolic compounds, found mainly in soybeans, known as isoflavonoids.

• While the chemopreventive properties of purified and synthetic isoflavonoids have been heavily investigated, a fermented soybean extract was recently shown to perform better at reducing the incidence of mammary tumor risk than a similar mixture of its constituent isoflavonoids, suggesting that the food background may play a positive role in the chemopreventive actions associated with soybean consumption, in addition to that of isoflavonoids.

Soybean Isoflavonoids

• Isoflavonoids are found mainly in soybeans, and possess a chemical structure that is similar to the hormone estrogen.

• The chief isoflavonoids found in soybeans are

genistein and daidzein.

• Because their structures resemble estrogen and they can interact with the estrogen receptor, soybean isoflavonoids are sometimes referred to as phytoestrogens.

• Phenolic compounds normally occur as glucoside bound moieties called glycones. However, it is the aglycone (glucoside free) form that is metabolically active.

• After consumption, microbial enzymes in the intestine cleave the glycoside moieties from glycone isoflavonoids and release the biologically active health-promoting aglycone isoflavonoids.

• Aglycone phenolic compounds possess higher antioxidant activity and are absorbed faster in the intestines than glucoside bound forms. Interestingly, fermented soy foods are rich in phenolic aglycones due to microbial bioprocessing during fermentation.

• However, once inside the bloodstream, biologically active aglycone genistein travels to the liver were it is converted back into an inactive glycone (b-glucuronide). Cellular glucuronidases must remove the glycone moiety before genistein can exert its biological activity.

• Isoflavonoids have been well studied and possess numerous biological activities. For example, genistein possesses inhibitory activity against topoisomerase II, tyrosine kinase, NF-κB, cancer cell proliferation, and nonoxidative pentose–phosphate pathway ribose synthesis in cancer cells.

• Many of the health-promoting benefits of isoflavonoids have been linked to the ability of phenolics to serve as antioxidants.

Health benefits of soybean isoflavonoids

• Soybean isoflavonoids may be useful for the treatment of somatic, mood, and cognitive disturbances associated with the onset of menopause.

• Soybean isoflavonoids may also have potential in natural chemoprevention therapies against long term health problems associated with menopause, particularly for osteoporosis.

• Estrogen positively affects the metabolism of calcium, lack of sufficient estrogen can lead to bone loss and osteoporosis.

• Soybean isoflavonoids also possess various biological activities that may help to explain the cancer chemopreventive properties associated with the consumption of soybean foods.

• In in vitro studies, daidzein was reported to stimulate the apoptosis, Genistein can stimulate antioxidant enzyme activities.

• Soybean consumption has also been linked to a reduced risk for cardiovascular disease.

• Addition of soybean into diets has been shown to result in reduced cholesterol isoflavonoid rich soybean in diets was also reported to protect against coronary heart disease by causing reductions in blood lipids, oxidized LDL, homocysteine, and blood pressure.

Probiotics

• Probiotics are feed and food supplements that beneficially affect the host’s health.

• Strain identity is important in order to link a strain to a specific health effect and to enable accurate surveillance and epidemiological studies.

• The term “probiotic” includes a large range of microorganisms, mainly bacteria but also yeasts.

• Because they can stay alive until the intestine and provide beneficial effects on the host health, lactic acid bacteria (LAB), non-lactic acid bacteria and yeasts can be considered as probiotics.

• LAB are the most important probiotic known to have beneficial effects on the human Gastro-Intestinal (GI) tract. These bacteria are Gram-positive and usually live in a non-aerobic environment but they also can support aerobic conditions.

• Bifidobacteria are also Gram-positive and can grow at a pH range of 4.5 – 8.5 but the most important characteristic is the fact that they are strictly anaerobic.

• Each species covers various strains with varied benefits for health. The probiotic health benefits may be due to the production of acid and/or bacteriocins, competition with pathogens and an enhancement of theimmune system.

• Dose levels of probiotics depend on the considered strain, but 106 – 107 CFU/g of product per day is generally accepted.

• Probiotics have been reported to play a therapeutic role by modulating immunity, lowering cholesterol, improving lactose tolerance and preventing some cancers.– Probiotics may influence the immune system

by means of products such as metabolites, cell wall components or DNA.

– The second mechanism of action can be described by a direct effect on other microorganisms which can be commensal and/or pathogenic.

– Probiotics have the ability to affect some microbial products such as toxins and host products like bile salts and food ingredients.

Synbiotics

a combination of the probiotics and prebiotics positives effects

• Prebiotics can be defined as ‘non-digestible food ingredients that, when consumed in sufficient amounts, selectively stimulate the growth and/or activity of one or a limited number of microbes in the colon resulting in documented health benefits.

• When considering probiotics, viability and dose level are important parameters for their efficacy and prebiotics have the potential to improve probiotic’s viability and vitality, its survival in the GI tract and its further attachment and growth in the intestine.

• Inulin and fructo-oligosaccharides are the most common prebiotics used, because of their resistance against gastric acid and pancreatic enzymes.

• The synbiotic concept can be defined as ‘a mixture of probiotics and prebiotics that beneficially affects the host by improving the survival and implantation of live microbial dietary supplements in the GI tract, by selectively stimulating the growth and/or activating the metabolism of one or a limited number of health promoting bacteria, and thus improving host welfare’.

Rice bran oil

• Interest in rice bran oil has been growing from the nutritional point of view.

• Rice Bran Oil contains three different kinds of natural antioxidants -- namely Tocopherol, Tocotrienol, and Oryzanol --.

• The unique components, such as oryzanol or tocotrienol, have been drawing people's attention.

• Numerous studies show rice bran oil reduces the harmful cholesterol (LDL) without reducing good cholesterol (HDL).

• In those studies, Oryzanol is reported as the key element responsible for that function.

• Tocotrienol, on the other hand, is highlighted as the most precious and powerful vitamin E existing in nature and is said to have an anti-cancer effect, too. As a Vitamin-E source, rice bran oil is rich not only in alpha Tocopherol but also has the highest amount of Tocotrienol in liquid form vegetable oils.

Oryzanol

• Oryzanol is one of the several minor components found in the unsaponifiable fraction of rice bran oil. It is a mixture of two or more ferulic acid ester of triterpene alcohols, cycloartenyl ferulate, -methylene cycloartanyl ferulate, b-sitosteryl ferulate and campesteryl ferulate. The ferulic acid is 4-hydroxy-3-methoxy cinnamic acid.

• Most of the biological activities of oryzanol are because of its excellent antioxidant property. Studies indicate that this phenolic antioxidant scavenges free radicals and prevent their formation inside our body metabolic process. The benefits resulting from this antioxidant activity are prevention against cancer, protection against heart disease by maintaining optimum cholesterol level and other factors like combating respiratory problems, diabetic health etc.

• This particular unsaponifiable material is considered to be an important factor in hypocholesterolemic and hypolipidemic action of rice bran oil.

• Studies indicated that oryzanol fed to humans and animals reduced LDL cholesterol and increased HDL cholesterol.

• It has been reported that hypertriglyceridaemia induced by fructose was significantly lower in animals which had been maintained on a diet containing 0.5% of this compound.