Piper sarmentosum

Journal of Ethnopharmacology 1998; 60:27-32

Hypoglycemic effect of the water extract of Piper sarmentosum in rats

Penchom Peungvicha ^a, Suwan S. Thirawarapan ^a, Rungravi Temsiririrkkul ^b, Hiroshi Watanabe ^c, Jeevan Kumar Prasain ^d, Shigetoshi Kadota ^d

^a Department of Physiology, Faculty of Pharmacy, Mahidol Uni6ersity, Bangkok 10400, Thailand ^b Department of Pharmaceutical Botany, Faculty of Pharmacy, Mahidol Uni6ersity, Bangkok 10400, Thailand ^c Department of Pharmacology, Research Institute for Oriental Medicine, Toyama Medical and Pharmaceutical Uni6ersity, Toyama 930- 01, Japan ^d Department of Natural Product Chemistry, Research Institute for Oriental Medicine, Toyama Medical and Pharmaceutical Uni6ersity, Toyama 930- 01, Japan

The hypoglycemic effect of the water extract of the whole plant of Piper sarmentosum Roxb. (Piperaceae, Thai name: Chaplu) was examined in normal and streptozotocin-diabetic rats. In an oral glucose tolerance test, a single oral administration of the water extract at doses of 0.125 and 0.25 g:kg significantly lowered the plasma glucose level in the normal rats. A reference drug, glibenclamide, at a dose of 5 mg:kg (per os, p.o.) also showed a significant hypoglycemic effect in the normal rats. In contrast, a single oral administration of the water extract at these doses and glibenclamide did not significantly lower the plasma glucose level in the diabetic rats. However, the repeated oral administration of the water extract at a dose of 0.125 g:kg for 7 days produced a significant hypoglycemic effect in the diabetic rats. Glibenclamide (5 mg:kg, p.o.) also caused significant hypoglycemia in the diabetic rats. These results demonstrated that the water extract of whole plant of Piper sarmentosum has a hypoglycemic effect in rats.