Total phenolic contents and free radical scavenging activities of different extracts of seabuckthorn (Hippophae rhamnoides) pomace without seeds

In this study, 100% methanolic extract (ME), 70% aqua-methanolic extract (AME) and 100% aqueous extract of seabuckthorn byproduct were used to evaluate antioxidant activity. The total phenolic contents were high in AME (84.28 +/- 1.58mg of Gallic Acid Equivalent (GAE)/gm of extract) compared to other extracts. All the extracts scavenged different in vitro radicals in a concentration-dependent manner. The IC50 values were lowest in AME for 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, 2,2-diphenyl-1-picrylhydrazyl, superoxide and nitric oxide radicals, while ME had lowest values for hydroxyl radicals. The reducing power of the extracts increased in a dose-dependent manner and was highest in AME. The findings of this study revealed that seabuckthorn pomace without seed is one of the important resources as an antioxidant for food, pharmaceuticals, cosmetic or nutraceutical industries.