Therapeutic Effects of Glycine Max (Soybean): a Summary
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International Journal of Research in Pharmacy and Biosciences Volume 2, Issue 1, January 2015, PP 22-27 ISSN 2394-5885 (Print) & ISSN 2394-5893 (Online) Therapeutic Effects of Glycine Max (Soybean): A Summary 1Dr Amit Sharma, 2Dr Zenis Baluja 1Assistant Professor, 2Demonstrator Department of Forensic Medicine, Hamdard Institute of Medical Sciences & Research, Jamia Hamdard, New Delhi-62 Abstract: The present generation is going through a major change in their approach to the idea of disease prevention where traditional medicine and medicinal foods are fastly replacing the conventional allopathic medicines. Soy rich food is one such example which is catching the attention of a common man as well as researchers due to its numerous health benefits.Soybeans is a rich source of isoflavones. Soy rich food and isoflavones are of great interest when it comes to medicinal foods .The various health benefits which are claimed by soybean consumption in any form includes as a Cholesterol lowering agent, as an Anticancer agent, for Prevention of bone loss in menopausal women, as an Antioxidant and chelating agent and prevention of Type 2 DM. Among all these beneficial effect, the most extensively researched upon properties are its cholesterol lowering effect ,its role in prevention of osteoporosis and its role as an anticancer agent .Other than this its role in cognition is also appreciated. This article provides a summary of various health benefits of soy consumption in diet while stressing upon the crucial ones in detail. Keywords: Soy diet; isoflavones; flavanoids; medicinal food; phytosterols 1. INTRODUCTION Glycine Max first originated in Southeast Asia around 1100BC in China. In 1904, George Washington Carver from America discovered that soybeans are a rich source of Protein and oil. In 1921, William Morse found out more than 10,000 different varieties of soybean. Earlier it was used for crop rotation and production of hay. During World War 2, soybeans were consumed as a high protein food and as edible oil. Soy is consumed in forms like soy flour, soy grits, soy proteins isolated, textured soy protein etc. Its flavoured and more popular forms includes soy based milk, curds, cheese, cereals, tofu, edamame, tempeh etc. are whole food forms of soy while the earlier are processed forms. Table1. Nutrional values of soybeans(per 100g): Water 8.5 g Energy 416 kcal Energy 1741 kJ Protein 36.5 g Fat (total lipid) 19.9 g Fatty acids, saturated 2.9 g Fatty acids, mono-unsaturated 4.4 g Fatty acids, poly-unsaturated 11.3 g Carbohydrates 30.2 g Fiber 9.3 g Ash 4.9 g Isoflavones 200 mg Calcium, Ca 277 mg Iron, Fe 15.7 mg Magnesium, Mg 280 mg Phosphorus, Mg 704 mg Potassium, K 1797 mg Sodium, Na 2.0 mg Zinc, Zn 4.9 mg Copper, Cu 1.7 mg ©IJRPB www.ijrpb.org 22 Dr Amit Sharma & Dr Zenis Baluja Manganese, Mn 2.52 mg Selenium, Se 17.8 µg Vitamin C (ascorbic acid) 6.0 mg Thiamin (vitamin B1) 0.874 mg Riboflavin (vitamin B2) 0.87 mg Niacin (vitamin B3) 1.62 mg Panthotenic acid (vitamin B5) 0.79 mg Vitamin B6 0.38 mg Folic acid 375 µg Vitamin B12 0.0 µg Vitamin A 2.0 µg Vitamin E 1.95 mg [Source: USDA Nutrient Database for Standard Reference] Recently the soy rich diet is being observed for its medicinal value and its incorporation as a integral part of diet on daily basis, for long term health benefits. Among all these health benefits reported and studied upon, its cholesterol lowering action is most vital in terming soy as a cardio -friendly food item. 2. CHOLESTEROL LOWERING EFFECT Several studies corroborate that the regular intake of legumes significantly decreases CVD.1 Specific studies on soybean remark that the substitution in the diet of animal protein for soybean protein, reduces the concentration of total and low-density lipoprotein (LDL) cholesterol in plasma and decreases triglycerides; high-density lipoprotein (HDL) cholesterol concentrations are not affected significantly.2 Soybean protein, as well as reducing cholesterol and triglycerides levels, may produce an increase of Lipoprotein A, which is potentially detrimental in antiatherogenic therapy. 3 Nevertheless, consumption of soybean protein helps to reduce cardiovascular disease risk,4,5 but the mechanisms responsible for the hypo cholesterolemic effect have not been identified. The lack of understanding of this mechanism remains an obstacle for a better acceptance of soybean protein by clinical community. There are different hypothesis to explain these mechanisms. One of these hypothesis is that amino acid composition or distribution in soybean change the cholesterol metabolism, possibly, due to changes in endocrine status, because there are alterations in insulin:glucagon ratio and thyroid hormone concentrations,6 as well as an increase in plasma thyroxin concentrations which is related with a reduction in plasma cholesterol.7 Another hypothesis proposes that non-protein components such as saponins, fibre, phytic acid, minerals and isoflavones associated with soybean protein affect cholesterol metabolism. The metabolic changes observed when soybean is introduced in the diet consist in an increased cholesterol synthesis, an increased bile acid synthesis or a faecal bile acid excretion, increased apolipoprotein B or E receptor activity and a decreased hepatic lipoprotein secretion and cholesterol from the blood.6 Early epidemiologic researches on dietary fibre from cereals and legumes indicated an inverse relationship between dietary fibre intake and coronary disease risk. Legumes constitute a source of dietary fibre, relatively rich in soluble fibre, which may play an important role in the prevention of heart disease.5 The major effects of soybean soluble fibres on serum lipoproteins appear to be related with bile acid binding and with a decrease in the reabsorption of bile acid.1 Therefore, there is an increase in the cholesterol used to synthesize bile acids. But also, the fermentation of soluble fibres in the colon produces short-chain fatty acids that contribute to reduce hepatic cholesterol synthesis.8 It has been shown that propionic acid, one of the short-chain fatty acids, decreases the hepatic cholesterol.9 Moreover, the diminution in the synthesis of cholesterol in the liver is due to a reduction in serum insulin concentrations because insulin is responsible of activating an enzyme that participates in cholesterol synthesis and, on the other hand, it might be due to an alteration of the bile acid profile in the liver.10 There is also a hypothesis that isoflavones ingested within a soybean containing diet may inhibit atherosclerotic development, because they have antioxidant properties against LDL oxidation, which generates a cascade of events producing atherosclerotic plaques. In addition, isoflavones possess a hypocholesterolemic effect, although this effect is still under investigation. It might be due to the interaction of isoflavones with estrogenic receptors, because of the structural similitude between these International Journal of Research in Pharmacy and Biosciences 23 Therapeutic Effects of Glycine Max (Soybean): A Summary compounds and their metabolites and estrogens. Serum cholesterol concentrations may decrease by similar mechanism.4 Different clinical researches indicate that to achieve a cholesterol-lowering effect,11 it is important to consume soybean protein with its natural isoflavones fraction.12 The hydrolysis of fibres to be used as supplements may also alter their physiological effects. Furthermore, although fibre-rich food is related with protection from CVD and has hypocholesterolemic effects, the separation of its natural compounds such as protein or isoflavones may reduce the cardiovascular and cholesterol effects.13 3. ANTICANCER EFFECT Another property of soybean which is of great clinical interest is its anti-cancer properties. It is very fascinating to learn how a mere legume can be useful in a condition as grave as cancer. It was for the first time reported that soybean agglutinin was capable of inhibiting the growth of tumor in rats.14 Pattern of lectin binding on the ell surface suggests about the type of malignancy of the tumor.15 These are also versatile markers, help in studies of various histochemical, biochemical, and functional methods for cancer cell classification.16 The exact mechanism is still not clear but lots of pathways are proposed for this. This has been found that targeting the surface lectins present on the tumor cells can be helpful for the treatment of cancer. Treatment with anti-lectin antibodies can help in suppressing the tumor growth and colonization.17 These can be used for studying the metastatic spreading pattern and the prediction of lymphatic attack.18 These can also be used as the carrier for targeted drug delivery. Soybean lectin is useful for analytical indicator of stomach cancer.19 Soybean agglutinin related with the recognition of the human lymphoma cells where sialylation of particular carbohydrate residues is associated with the spontaneously metastatic capacity of human lymphoma cell lines.20 The number of macrophages increase with the SBL treated cells over the control. 21 Another study focuses on the human bone marrow cells which were mixed with the neuroblastoma cells from different cell line and then mixtures are separated by the SBL where all the neuroblastoma cells expressed the presence of receptor for SBL. By targeting SBA bound toxins, improved purging of neuroblastoma cells was achieved in another test Burkitt’s lymphoma cells were purged where it showed the similar results.22 It shows its effect upon the transplants of leukemia patients 23 another mechanism called the Cytoagglutination or aggregation by which the interaction of cancer cells can be detected.24 There are many bioactive peptides which can be derived from soybean protein which are having many effects on health and can be used for age-related chronic disorders, such as cardiovascular disease, obesity, decrease immune function and cancer. In contrast to most small-molecule drugs, peptides have high affinity, strong specificity for targets, low toxicity and good penetration of tissues.