Purpose: To evaluate the α-glucosidase inhibitory activity of Croton bonplandianum Baill as a probable remedy for the management of diabetes.

Methods: Dichloromethane and methanol extracts were prepared and screened for their α-glucosidae inhibitory activity using standard in vitro α-glucosidae inhibition assay. Acarbose was used as positive control.

Results: α-Glucosidae inhibition activity of dichloromethane extract was 97.89 % with 50 % inhibitory concentration (IC₅₀) of 14.93 mg/ml, while the methanol extract was not active. Acarbose (reference) exhibited 92.23 % inhibition with IC₅₀ of 38.25 mg/ml.

Conclusion: The plant contains bioactive compounds with enzyme-inhibiting activity, and thus lends some support for the traditional use of this herb in the management of diabetes. Dichloromethan extract has higher α-glucosidase inhibition activity than the methanol extract.  However, further investigation of the plant, including identification of its active components are required.