Journal of Berry Research 7 (2017) 61–69 DOI:10.3233/JBR-170147 IOS Press 61 Sexual differences and seasonal variations in total phenolics and antioxidant properties in Hippophae rhamnoides leaves Phuntsog Dolkar a , Diskit Dolkar a , Stanzin Angmo a , Anil Kant b , Bhuvnesh Kumar a and Tsering Stobdan a,∗ a Defence Institute of High Altitude Research, DRDO, Leh, Jammu and Kashmir, India b Jaypee University of Information Technology, Wakhnaghat, Solan, Himachal Pradesh, India Received 14 November 2016; accepted 11 January 2017 Abstract. BACKGROUND: Seabuckthorn (SBT) leaves are used for extraction of health promoting compounds and product develop- ment. 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 activity was significantly higher in males (6.5 ± 1.1 Fe 2+ mmol/g DW) than females (6.1 ± 1.2 Fe 2+ 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. Keywords: Dioecious, Himalaya, Polyphenols, reproductive effort, Seabuckthorn 1. Introduction Seabuckthorn (Hippophae rhamnoides L.) is an ecologically and economically important plant [1]. The species is native to Europe and Asia, but nowadays it is widely grown all over the world. Seabuckthorn (SBT) is dioecious and wind pollinated plant. Traditionally, every part of the plant is being used for a variety of purpose. There are over a hundred popular SBT-based formulations in various pharmacopoeias of Sowa Rigpa (Tibetan medicine) [2]. Although the nutritional and medicinal properties of SBT berries are usually the focus of attention, SBT leaf has been receiving much attention in recent years for its medicinal and therapeutic applications. SBT leaves possess ∗ Corresponding author: Tsering Stobdan, Defence Institute of High Altitude Research, DRDO, Leh, Jammu and Kashmir 194101, India. Tel.: +91 9419176057; Fax: +91 1982 252096; E-mail: ts mbb@yahoo.com. 1878-5093/17/$35.00 © 2017 – IOS Press and the authors. All rights reserved