Effect of kolaviron on islet dynamics in diabetic rats

Kolaviron, a biflavonoid isolated from the edible seeds of Garcinia kola, lowers blood glucose in experimental models of diabetes; however, the underlying mechanisms are not yet fully elucidated. The objective of the current study was to assess the effects of kolaviron on islet dynamics in streptozotocin-induced diabetic rats. Using double immunolabeling of glucagon and insulin, we identified insulin-producing β- and glucagon-producing α-cells in the islets of diabetic and control rats and determined the fractional β-cell area, α-cell area and islet number. STZ challenged rats presented with islet hypoplasia and reduced β-cell area concomitant with an increase in α-cell area. Kolaviron restored some islet architecture in diabetic rats through the increased β-cell area. Overall, kolaviron-treated diabetic rats presented a significant (p < 0.05) increase in the number of large and very large islets compared to diabetic control but no difference in islet number and α-cell area. The β-cell replenishment potential of kolaviron and its overall positive effects on glycemic control suggest that it may be a viable target for diabetes treatment.