Antihyperglycaemic and antinociceptive activity evaluation of methanolic extract of whole plant of Amaranthus tricolour L. (Amaranthaceae).

Amaranthus tricolor whole plants are used by folk medicinal practitioners of Bangladesh for treatment of pain, anaemia, dysentery, skin diseases, diabetes, and as a blood purifier. Thus far, no scientific studies have evaluated the antihyperglycaemic and antinociceptive effects of the plant. The present study was carried out to evaluate the possible glucose tolerance efficacy of methanolic extracts of A. tricolour whole plants using glucose-induced hyperglycaemic mice, and antinociceptive effects with acetic acid-induced gastric pain models in mice. In antihyperglycaemic activity tests, the extract at different doses was administered one hour prior to glucose administration and blood glucose level was measured after two hours of glucose administration (p.o.) using glucose oxidase method. The statistical data indicated the significant oral hypoglycaemic activity on glucose-loaded mice at all doses of the extracts tested. Maximum antihyperglycaemic activity was shown at 400 mg extract per kg body weight, which was comparable to that of a standard drug, glibenclamide (10 mg/kg body weight). In antinociceptive activity tests, the extract also demonstrated a dose-dependent significant reduction in the number of writhings induced in mice through intraperitoneal administration of acetic acid. Maximum antinociceptive activity was observed at a dose of 400 mg extract per kg body weight, which compared favourably with that of a standard antinociceptive drug, aspirin, when administered at a dose of 200 mg per kg body weight. The results validate the folk medicinal use of the plant for reduction of blood sugar in diabetic patients as well as the folk medicinal use for alleviation of pain. The results suggest that this plant may possess further potential for scientific studies leading to possible discovery of efficacious antihyperglycaemic and antinociceptive components.

Evaluation of antinociceptive and antihyperglycemic activities in methanol extracts of whole plants of Alternanthera philoxeroides (Mart.) Griseb. (Amaranthaceae) in mice.

The present study evaluated the antinociceptive and antihyperglycemic effects of crude methanol extract of whole plants of Alternanthera philoxeroides (Mart.) Griseb. (Amaranthaceae) in Swiss albino mice. Antin(o)Ciceptive activity was evaluated by attenuation of the number of constrictions in acetic acid-induced gastric pain, while antihyperglycemic activity was evaluated through oral glucose tolerance tests in glucose-loaded mice. Dose-dependent and significant inhibitions in the number of constrictions were seen in mice administered with extract at doses of 50, 100, 200 and 400 mg per kg body weight. At these concentrations, the numbers of constrictions were reduced, respectively, by 31.0, 32.7, 37.9 and 44.8%. In comparison, a standard antinociceptive drug, aspirin reduced the number of constrictions by 37.9 and 67.2%, when administered at doses, respectively, of 200 and 400 mg per kg body weight. The extract also exhibited dose-dependent and significant antihyperglycemic activity when administered to mice at the afore-mentioned four doses. Serum glucose concentrations were reduced, respectively, by 36.3, 58.6, 65.0 and 65.6% at the four doses administered. The results compare favorably with a standard antihyperglycemic drug, glibenclamide, which when administered at a dose of 10 mg per kg body weight reduced serum glucose level by 42.7%. Taken together, the results obtained indicate that the extract merit further scientific studies towards discovery of components, which may prove beneficial in ameliorating pain, as well as high sugar levels of diabetic patients.