[The cholesterol-lowering effect of black beans (Phaseolus vulgaris, L.) without hulls in hypercholesterolemic rats]. / Efeito do feijão preto (Phaseolus vulgaris, L.) sem casca na redução do colesterol sangüíneo de ratos hipercolesterolêmicos.

The cholesterol-lowering property of beans has been shown in several studies. The propose of the present work was to investigate the effect of black beans (Phaseolus vulgaris, L.) without hulls on blood cholesterol of hypercholesterolemic rats. Four groups of 8 male rats, Wistar strain, initial body weight of 200 g were kept at +/- 25 degrees C in a light-dark cycle of 12 h, for 28 days. The group Standard received a basal casein diet. Group Control received the basal diet added of 1% cholesterol plus 0.1% cholic acid. The group BB received a diet similar to the Control, substituted by 30% black beans, on dry-weight. The group SBB received black beans without hulls, equivalent to 30% of whole beans. The addition of cholesterol and cholic acid raised blood cholesterol levels of rats on Control diet by 58%, in relation to the Standard. BB diet reduced blood cholesterol by 15% (non-significant-NS) and SBB diet reduced (p < 0.05) by 35%, in relation to the Control diet. The levels of HDL-cholesterol were reduced (p < 0.05) by both bean diets. SBB diet promoted a higher excretion of fecal cholesterol, compared to the Control. This suggests that beans without hulls promote a higher cholesterol output and that the whole beans, although had lowered blood cholesterol (NS), kept it in the enterohepatic circulation. The hypocholesterolemic compounds of beans seem to be located in the inner part of the grain. Further studies are necessary to identify these compounds and to elucidate their mechanisms of action.

[The cholesterol-lowering effect of black, carioquinha and red beans (Phaseolus vulgaris, L.) in hypercholesterolemic rats]. / Efeito dos feijões (Phaseolus vulgaris, L.) preto, carioquinha e vermelho na redução do colesterol sangüíneo de ratos hipercolesterolêmicos.

The propose of the present work was to investigate the cholesterol-lowering effect of black carioquinha and red beans (Phaseolus vulgaris, L.), widely consumed in Brazil, in hypercholesterolemic rats. Five groups of 8 male rats, Wistar strain, initial body weight of 200 g were kept at 25 degrees in a light-dark cycle of 12 h, for 28 days. The group Standard received a basal casein diet. Group Control was formulated by the addition of 1% cholesterol to the basal diet to produce hypercholesterolemia in the rats. The other groups received similar diets to the Control, substituted by 30% black (BB), carioquinha (CB) or red (RB) beans, on dry-weight. The addition of 1% cholesterol promoted an increase of 49% in the levels of total blood cholesterol on Control group, compared with the Standard. The bean diets reduced total blood cholesterol (non-significant): BB reduced 16%, RB 12% and CB 11%, in relation to the Control. The addition of cholesterol to the diets promoted lipid deposition in the rat livers, even in those fed the bean diets. It seems that the reduction of cholesterol in blood is followed by its retention in the rat livers.