Vitex agnus castus fruit essential oils: a study of Cretan inter population variation and the influence of the maturity, comminution, extraction time and method on the essential oil yield and composition

The fruits of Vitex agnus castus L. exhibit a remarkable action on especially the female hormonal system by exerting a progesterone-like activity. The chemical compounds responsible for this activity have not been identified. Progesterone deficiency is found a major factor in several serious diseases including cancer and osteoporosis. A review of the role of progesterone in the human body is therefore included in Appendix I of this study. In the present study , the hydrodistilled essential oils of mature fruits from five Cretan V. agnus castus wild growing populations were analysed by GC and GC/MS. More than 70 constituents were detected, of which 49 comprising 87 per cent of the total oil were identified. The major components were sabinene, 1.8 cineole and trans-beta-farnesene, alpha-pinene and trans-caryophyllene. In essential oil,yield and quantitative composition the populations differed highly significant between each other. The effect of the comminution, the pre-soaking and the maturity of the plant material showed highly significant differences in the yield and the qualitative composition of the essential oils obtained as well as the distillation duration from one to five hours and the extraction method applied (Hydrodistillation and Simultaneous Distillation Extraction). The quantitative variation of 35 V. agnus castus fruit essential oil components due to the parameters applied is studied. The results show, that many substantially different essential oil qualities can be obtained from the same plant material according to the parameters employed in its extraction. Mature fruits hydrodistilled entire for one hour yield an oil much richer in monoterpene hydrocarbons, and oxygenated compounds whereas the best combination to obtain an oil rich in less volatile compounds is extraction (SDE) of comminuted immature fruits for five hours. The essential oil components of immature fruits were significantly less influenced by the comminution, the hydrodistillation duration as well as the extraction method compared to mature fruits.