Abstract:
Introduction: Coccinia grandis (L.) Voigt (Family: Cucurbitaceae) has traditionally
been used as an anti-diabetic phyto-medicine. The efficacy of antihyperglycaemic activities
of the Coccinia grandis extract was determined in diabetic rats previously by our group.
However, detailed antihyperglycaemic mechanisms of the C. grandis extract (0.75 g/kg)
on the pancreas have not been reported in diabetic rats. Therefore, this study aimed to
investigate the effect of leaf extract of C. grandis on the regenerative potency of pancreatic
p-cells in streptozotocin induced diabetic rats. Methods: Wistar rats were divided into
four groups (n=6/group); healthy untreated rats, streptozotocin-diabetic untreated rats
(65 mg/kg, ip), diabetic rats receiving the aqueous leaf extract of C. grandis (0.75 g/kg) and
diabetic rats receiving glibenclamide (0.50 mg/kg). The treatment continued for 30 days.
The pancreas was excised from sacrificed rats in all groups. Immunohistochemical staining '
was done on paraffin embedded tissue blocks of the pancreas to confirm the presence of
insulin secreting p-cells. Results: There was an increase in the number of islets and the
percentage of insulin secreting P-cells in plant extract treated diabetic rats compared to
untreated diabetic control rats. In addition, the C. grandis extract produced a significant
increase in mean islet profile diameter in small (111% p=o.oio), average (6% p=0.040),
and large (16%, p=o.oio) islets as compared with streptozotocin induced diabetic control
rats. There was a slight improvement in the percentage of p-cells in glibenclamide treated
diabetic rats. However, the islet profile diameter was not altered with the treatment of
glibenclamide (p=o.055). Conclusion: The results revealed that the aqueous leaf extract
of C. grandis (0.75 g/kg) induces p-cell regeneration in the pancreas of streptozotocin
induced diabetic rats. Therefore, it could be considered as one important mechanism in
which the leaf extract of C. grandis exerts it’s antihyperglycaemic activity in vivo.
