Free radical scavenging and lipid peroxidation of Thai medicinal plants used for diabetic treatment.

OBJECTIVE

To investigate antioxidant activities of some selected plants used to treat diabetic patients by Thai folk doctors.

METHODS

Ten Thai plants were selected, macerated and extracted with 95% ethanol. DPPH scavenging and lipid peroxidation assays were used to test the antioxidant activities of the extracts.

RESULTS

Mammea siamensis (Saaraphee), Tacca chantrieri (Narapusri) and Albizia myriophylla (Cha Em Thai) showed the highest antioxidant activity on DPPH radical assay (EC50 = 10.17, 10.24 and 14.45 microg/ml, respectively). Mimussops elengi (Pikun), M. siamensis (Saaraphee) and A. myriophylla (Cha Em Thai) exhibited the highest antioxidant activity by lipid peroxidation assay (IC50 0.39, 0.43 and 0.70 microg/ml, respectively). Six often plant extracts showed antioxidant activity on both assays (IC50 < 20 microg/ml).

CONCLUSIONS

These plant extracts containing in Thai folklore antidiabetic medicine, which showed high antioxidant activity, may be used effectively for the treatment of diabetic patients.