Sexual Differences and Seasonal Variations in Total Phenolics and Antioxidant Properties in Hippophae Rhamnoides Leaves

BACKGROUND: Seabuckthorn (SBT) leaves are used for extraction of health promoting compounds and product development.OBJECTIVE: The aim of the work was to find out gender differences and seasonal variation in total polyphenol content (TPC) and total antioxidant capacity (TAC).METHOD: Leaves of six natural population of SBT, which comprised 200 plants (100 males, 100 females) from the trans-Himalaya were harvested, and their methanolic and acetone extracts were studied for TPC and TAC.RESULTS: Males exhibit significantly higher TPC (100.8 +/- 23.9 mg GAE/g DW) than females (95.0 +/- 23.8 mg GAE/g DW). Similarly, ferric reducing activitywas significantly higher in males (6.5 +/- 1.1 Fe2+ mmol/gDW) than females (6.1 +/- 1.2 Fe2+ mmol/g DW). Significant increase in TPC was observed in male leaves from July to October followed by a significant decrease in November. However, a trend of increase in TPC upto August and a steady decline thereafter was observed in leaves of female SBT. Similarly a trend of an increasing TAC was observed in both the sexes but female leaves were observed to be on an increasing TAC from July to October.CONCLUSION: Male SBT leaves exhibit higher TPC and TAC than females; October is the best time for harvesting SBT leaves and; SBT leaves contain significantly higher hydrophilic than lipophilic phenolics and antioxidants.