BLACK GRAM ( Vigna mungo ) - A hypolipidemic pulse

Cardiovascular problems have been haunting human populations for a long time with no specific cure. It is believed that a shift in the eating, and physical habits might have paved the way for the alarming increase in cardiovascular diseases. Increase in the lipid level has been pinpointed as an important risk factor. Hence epidemiological and clinical studies were undertaken throughout the world to find an answer to this. We also attempted in a small way to find out whether the commonly consumed pulses have any correlation with the lipid profile (Devi & Kurup, 1970). Black Gram [Vigna mungo (Linn.) Hepper syn. Phaseolus mungo Linn., non Roxb. & auct; Phaseolus radiatus Roxb., Hindi-Urd] is a highly prized pulse. The main areas of production are Madhya Pradesh, Uttar Pradesh, Punjab, Maharashtra, West Bengal, Andhra Pradesh and Karnataka. It is mostly consumed as pulse and in the preparation of typical Indian dishes like pappad, idli, dosa and vada. It is a good source of phosphorus. Our investigations led to the conclusion that black gram has significant lipid lowering action. So, further studies were focussed to find out the active principles present in black gram responsible for that effect. A protein and a polysaccharide fraction were isolated from black gram. The globulin fraction at 5% level brought down the cholesterol and triglycerides in the serum, liver and aorta of rats fed high fat, high cholesterol diet to normal levels. Limited numbers of human studies were also carried out which indicated the hypocholesterolemic and hypotriglycerdemic effects of the protein. The polysaccharide fraction at 56% had a similar action, but to a lesser extent. The protein fraction contained carbohydrate residues and SDS PAGE electrophoresis showed that it was a heterogeneous mixture. Studies on the mechanism of hypolipidemic action revealed that even though the protein fraction increased cholesterol absorption, caused more hepatic degradation of cholesterol to bile acids and their fecal excretion (Devi & Kurup, 1972, 1973; Menon & Kurup, 1976). Regression of the experimentally induced atherosclerosis has also been studied with this fraction. Both biochemically and histochemically significant regression of atherosclerotic plaques were observed (Jayakumari et al, 1978). The proteolysis of this protein was also done and the action of this enzymatic hydrolysate was also studied. But these studies showed that the intact protein was more effective indicating the role of carbohydrates bound to the protein and its intact three dimensional structure (Kurup & Kurup, 1982). Impact of this protein fraction on glycoaminoglycans (GG) was also studied. Heparin sulphate and chondroitin sulphate decreased while other GG fractions were unaffected (Menon & Kurup, 1974, 1975). The implications of this observation have to be viewed in the light of the accumulation of GG reported in the coronary or cerebral arteries in heart attacked /stroke patients. At this time role of dietary fiber in reducing atherosclerosis is gaining importance. Trowell (1975) suggested that natural carbohydrates, especially those rich in dietary fiber might protect against atherosclerosis and might reduce hypercholesterolemia. We estimated the fibre content of various purified starches and Abstract