Evaluation of phytochemical constituents and antioxidant activity of selected actinorhizal fruits growing in the forests of Northeast India

Hippophae salicifolia, Elaeagnus pyriformis, Myrica esculenta and M. nagi are actinorhizal plants growing in the sacred forests of Northeast India with multipurpose uses. The present investigation was undertaken to determine the phenol, flavonoid and flavonol contents of the fresh fruit juice of these plant species including the antioxidant potential by means of DPPH, H₂O₂ and NO scavenging activity and FRP. The total phenolic, flavonoid and flavonol contents of fruit juice ranged from 321.68±0.06 to 76.67±0.01 mg/g GAE, 272.92±0.07 to 20.12±0.02 mg/g QE and 258.92±0.08 to 18.72±0.02 mg/g QE, respectively. At 2.0 mg/mL concentration, DPPH scavenging activity was found to be the highest in M. esculenta (89.62%) and the lowest in E. pyriformis (17.58%). The reducing power activity was found significantly higher in H. salicifolia juice, which increased with increase in concentration. The H₂O₂ scavenging activity of H. salicifolia juice was found to be as high as 98.78%, while Elaeagnus juice was found to be less effective with just 48.90%. Juice of H. salicifolia showed the greatest NO scavenging effect of 75.24% as compared to juice of E. pyriformis, where only 37.54% scavenging was observed at the same concentration. Taking into account all the experimental data, it can be said that the fruits of H. salicifolia and both M. nagi and M. esculenta have good antioxidant activity compared to fruits of E. pyriformis.