To investigate the anti-dyslipidemic, anti-oxidant and anti-diabetic activities of the aqueous extract and solvent fractions of Allamanda violacea
The aqueous extract was fractionated into petroleum ether, ether, chloroform, chloroformmethanol (4:1) and chloroform-methanol (3:2) fractions. Lipid lowering activity was evaluated in two models, viz, triton WR-1339 - induced hyperlipimea in rats as well as fructose-rich high fat diet. To assess anti-oxidant activity, in-vitro model of non-enzymic superoxide hydroxyl radicals and microsomal lipid peroxidation by non-enzymic inducer was adopted. Hypoglycemic activity was evaluated by sucrose-loaded rat model.
Amongst the fractions, ether and chloroform fractions caused marked decrease in the levels of total cholesterol (Tc), triglycerides (Tg), plasma lipids (Pl), and protein by 24, 23, 23 and 22 %, and 24, 22, 23 and 19 %, respectively. In rats fed with high fat diet (HFD), ether and chloroform fractions lowered Tc, Tg and, Pl by 26, 25 and 26 %, and 18, 19 and 20 %, respectively. Significant decrease in superoxide anions, hydroxyl radicals and microsomal lipid peroxidation by ether and chloroform fractions was also observed. Chloroform, chloroform-methanol (4:1) and chloroform-methanol (3:2) fractions showed antihyperglycaemic activity to the extent of 25.2, 21.6 and 23.2 %, respectively.
The flowers of this plant, especially the ether and chloroform extracts, may be suitable for anti-oxidant use and lipid management.