Variability in phenolics, flavonoids and antioxidants in Seabuckthorn ( Hippophae rhamnoides L.) seed from nine trans-Himalayan natural population

BACKGROUND: Seabuckthorn (SBT) has recently gained worldwide attention for its medicinal and nutritional potential. Many of the claims associated with SBT are related to its phenolics and antioxidants. OBJECTIVE: The work aimed at studying the variability and genotypic effects on total phenolic content (TPC), total flavonoid content (TFC) and total antioxidant capacity (TAC) in seed. METHOD: Seed extracts of nine natural population of SBT (122 plants) were studied for TPC, TFC and TAC content. RESULTS: SBT seed were found to be rich in TPC ranging from 32 to 208 mg gallic acid equivalent/g DW. Flavonoid content ranged from 8 to 38mg quercetin equivalent/g of DW. The free radical-scavenging activity in terms of inhibitory concentration (IC50) ranged from 0.3 to 9.2 mg/ml and ferric reducing antioxidant potential (FRAP) from 11 to 97 mmol Fe (II)/g. CONCLUSION: A variation of 1-6.5 fold in TPC, 1-4.7 fold variation in TFC, 1-8.8 fold in ferric reducing antioxidant potential and, 1-30.6 folds in IC50 by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay among the examined seeds across nine populations underlines the important role played by genetic background and the geographical location for determining the health promoting compounds.