Experimental Evaluation of Analgesic and Antioxidant Effects of Hydromethanolic Extract of Dioscorea dumetorum Tuber

Aims: The hydromethanolic extract of D. dumetorum was evaluated for antinociceptive and antioxidant activities to validate its uses in traditional medicine for these purposes.

Methods: The antioxidant activity of D. dumetorum was done in vitro using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) photometric assay. The antinociceptive effect of the extract were investigated using acetic acid-induced writhing reflex and tail flick models with aspirin and pentazocine as reference drugs respectively.

Results: The extract (200 mg/kg) produced a comparable effect to aspirin (100 mg/kg) in the acetic acid induced abdominal writhing reflex. In tail flick respond model, the extract produced significant (P<0.05) dose-dependent increase in pain reaction time (PRT) in the treated rats when compared to the distilled water treated rats. The extract (200 mg/kg) and pentazocine (3 mg/kg) produced 62.86 and 62.52% increase in PRT, respectively when compared to the negative controls. Similarly, DPPH radical scavenging activity of D. dumentorum extract produced concentration-dependent increase in the percentage antioxidant activity in the DPPH photometric assay. The extract at 400 μg/ml concentration produced antioxidant activity comparable to the standard.

Conclusion: The results of our study confirmed the uses of D. dumetorum in traditional medicine and provided evidence that tuber extract of D. dumetorum might indeed be potential sources of natural antinociceptive and antioxidant agents.