Oral glucose tolerance test (OGTT) in normal control and glucose induced hyperglycemic rats with Coccinia cordifolia l. and Catharanthus roseus L.

The aim of this study is to investigate the hypoglycemic effects of petroleum ether, chloroform and ethyl acetate fractions isolated from ethanolic extracts of Coccinia cordifolia and Catharanthus roseus on normal control and orally glucose-induced hyperglycemic rats. Single doses (150 mg/kg) of different fractions of C. cordifolia and C. roseus extracts were intraperitonelly administered. The serum blood glucose level was obtained by pricking the tail vein using glucometer at time 0, 30, 60, 90, 150 and 270 minutes. In the orally glucose induced hyperglycemic rats, chloroform-coccinia (CHCl3-CC) fraction showed maximum reduction of blood glucose level by 21.94% on 60 minute of the experiment. On the other hand maximum reduction (p<0.05) of 17.92% was observed for petroleum ether-catharanthus (PET-CR) on 30 minute of the experiment. Metformin HCl was used as standard drug. Our results indicate that the CHCl3-CC fraction is relatively more potent than other fractions of C. cordifolia. Similarly the PET-CR is found to be better than other fractions of catharanthus. Phytochemical screening test results showed that chloroform fraction of C. cordifolia contain saponins and flavonoids compounds, which are known to be hypoglycemic. On the other hand petroleum ether fraction of C. roseus contains tannins, flavonoids and alkaloid compounds produced varying degree of blood sugar reduction. On the pharmacological point of view C. cordifolia and C. roseus appears to be a valuable plant, which can be useful, at least as an adjunct, in the therapy of diabetes.