Antioxidant activity of some wild edible plants of Meghalaya state of India: A comparison using two solvent extraction systems

The objective of the present study was to find out the antioxidant potential of some wild edible plants, traditionally used by the local people of Meghalaya state in India and also to investigate the effect of solvent extraction system (aq. methanol and acetone) on the total phenolic, flavonoids and flavonols content, reducing power and antioxidant activity of the plants. The total phenol content varied from 3.31±0.10 to 27.67±0.16 mg/g in the aqueous methanol extract and 2.61±0.13 to 6.85±0.13 mg/g in the acetone extract of the plants. Flavonoids content were between 8.11±0.071 and 52.14±0.004 mg/g in aqueous methanol extract and varied from 1.22± 0.01 to 52.17± 0.01 mg/g in the acetone extract. 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging effect of the extracts were determined spectrophotometrically. The highest radical scavenging was observed in the aq. methanol extract of Gentiana pedicellata with IC50 = 0.23±0.0007 mg dry material. The greater amount of phenolic compounds, flavonoids and flavonol content leads to more potent radical scavenging effect as shown by the aq. methanol extract of G. pedicellata. Flavonol content was observed highest in the aq. methanol extract of G. pedicellata (23.12 ±0.006 mg/g) and least in the acetone extract of Gynocardia odorata (0.09±0.008 mg/g). The reducing power of the extracts of the plants were also evaluated as mg AAE (ascorbic acid equivalent)/g dry material and highest reducing power (16.11 ± 0.03) observed in the aq. methanol extract of Bauhinia purpurea, which contain maximum amount of phenolic compounds (27.67±0.16 mg/g GAE). The results indicate that the type of extragent significantly influenced the antioxidant activity of these wild edible plants and could be utilized as potential source of natural antioxidant in the food or in pharmaceutical industry.