Investigation of Antioxidant Activity of Methanolic Extracts of Hippophae rhamnoides ssp. turkestanica across Habitats in Cold Desert Biosphere Reserve, Trans Himalaya, India”

摘要

The present study evaluated phenolic compounds and antioxidant properties of leaf, stem and root methanolic extracts of a high altitude species, Hippophae rhamnoides L. ssp. turkestanica Rousi (Elaeagnaceae). H. rhamnoides ssp. turkestanica was collected from four distantly located populations in Cold Desert Biosphere Reserve. Total phenolic contents across populations were ranged from 62±2.81 to 78±0.61; 80±2.67 to 98±0.62 and 77±3.83 to 97±0.35 mg GAE g-1 of extracts in leaves stems and roots, respectively. Flavonoid contents across populations ranged from 26±0.48 to 36±0.48; 34±4.38 to 53±5.59 and 65±0.48 to 75±0.28 mg QE g-1 of extracts in leaves, stems and roots, respectively. Phenolic and flavonoid contents were significantly higher in the stem and root extracts as compared to leaf extracts. One way analysis of variance (ANOVA) revealed significant variation among populations. All extracts exhibit strong antioxidant activity determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis (3- ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) and reducing power, assays. The percent inhibition was found to increase with every unit increase in concentration. The DPPH and ABTS radical scavenging reached up to 88.38 % and 99.49 % at a concentration of 400 ??g mL-1, respectively. Reducing power ranged from 0.203 to 0.593 at concentrations ranging from 50 to 400 μg mL–1. Therefore, present study strongly supports Hippophae rhamnoides ssp. turkestanica as a potent source of antioxidant and could be utilised as natural source of antioxidants in pharmaceuticals and food industry.