Phytochemical, Antioxidant and Antifungal Investigations of Vitex agnus-castus Leaf Essential Oil

Vitex agnus–castus, belonging to the Lamiaceae family, is used in traditional medicine in Iran. With the aim of finding natural compounds with anti–fungal and eco–friendly properties, the effect of Vitex agnus–castus essential oil on mycelial growth of three plant pathogenic fungi was evaluated. The study was conducted as factorial experiments with three fungal isolates, including Botrytis cinerea, Penicillium digitatum and Aspergillus flavus. The inhibitory activity of six doses of the essential oil (2, 4, 8, 16, 32 and 64 μl) with three replicates were examined. Also, the antioxidant effect of the oil was evaluated by DPPH free radical inhibition method. The chemical compounds of the oil were identified and quantified using GC–MS method. Analysis of the chemical composition of the essential oil showed that α–pinene (52.70%), limonene (15.77%) and (E)–caryophyllene (8.69%) constitute the most components of the essential oil, respectively. As results of the study showed that the 64 ml of V. agnus–castus essential oil has the greatest inhibitory effect on mycelial growth of studied fungi. Among the studied fungal species, P. digitatum showed the least and B. cinerea showed the most sensitivity to the of V. agnus–castus essential oil. Also, the essential oil was showed a high antioxidant activity with IC50 value of 0.07 mg/ml compared to the BHT (IC50 = 0.04 mg/mL), as a synthetic antioxidant..