Sex-related differences in essential oil composition, phenol contents and antioxidant activity of aerial parts in Pistacia lentiscus L. during seasons

Essential oil composition, total phenolic, flavonoid and condensed tannin contents were assessed in different aerial parts of the same females and males of Pistacia lentiscus over four harvesting times. Marked quantitative and qualitative in terpenic and phenolic composition depending on sex, plant part and collecting periods were observed. At the species level, the main major compounds of essential oils in the leaves and stems were alpha-limonene, alpha-pinene, germacrene-D and beta-myrcene with female plant stems being rich in these compounds. Male flowers produced highest amounts of alpha-terpinen-4-ol and beta-caryophyllene, whereas, fruits accumulate the highest level of beta-myrcene. alpha-limonene and germacrene-D reached their highest contents at fruiting in females and at flowering in males. The highest total phenolic, flavonoid and condensed tannin contents were higher in male leaves and flowers, with marked decreasing of contents from the vegetative to the ripening period. The antioxidant activity of acetonic extracts assessed by the DPPH and FRAP assays differs significantly among aerial plant parts. The lowest averages of IC50 were observed in leaves at the vegetative and the flowering stages, respectively. The ferric reducing antioxidant ability (FRAP) for leaves and stems differs between sexes and organs with male extracts taken during the vegetative and flowering stages being more active. The revealed differences in chemicals and antioxidant activities among genders, organs and phenological stages should help to the optimization of P. lentiscus use in industrial and pharmaceutical fields according to the variation of its chemical composition.