Investigation of antidiabetic potential of Phyllanthus niruri L. using assays for α-glucosidase, muscle glucose transport, liver glucose production, and adipogenesis.

Phyllanthus niruri is used in herbal medicine for treatment of diabetes. The objective of this study was to investigate the antidiabetic potential of P. niruri, using assays for α-glucosidase, muscle glucose transport, liver glucose production and adipogenesis. α-Glucosidase inhibitory activity was performed on aqueous and ethanolic extract of aerial parts of P. niruri. The aqueous and ethanolic extract of P. niruri showed α-glucosidase inhibitory activity with IC50 values of 3.7 ± 1.1 and 6.3 ± 4.8 μg/mL, respectively. HR-bioassay/HPLC-HRMS and NMR analysis was used for identification of compounds. Corilagin (1) and repandusinic acid A (2) were identified as α-glucosidase inhibitors in the water extract of P. niruri with IC50 values of 0.9 ± 0.1 and 1.9 ± 0.02 μM, respectively. In in vitro cell-based bioassays, cells were treated for 18 h with maximal non-toxic concentrations of the ethanolic extract of P. niruri, which were determined by the lactate dehydrogenase cytotoxicity assay. The ethanolic extract of P. niruri was not able to reduce glucose-6-phosphatase activity. However, the extract increased deoxyglucose uptake in C2C12 muscle cells and enhanced adipogenesis in 3T3-L1 fat cells which has been reported for the first time. The present study demonstrated that P. niruri may thus have potential application for treatment and/or management of type 2 diabetes.