Chemical Analysis and Toxicity Screening of Phlomis olivieri Benth. and Phlomis persica Boiss. Essential Oils

Background:Phlomis olivieri Benth. and Phlomis persica Boiss. (Lamiaceae) are two medicinal species endemic to Iran. In the present study, we investigated the chemical compositions and general toxicity potentials of the essential oils obtained from the aerial parts of these two Phlomis species. Method: The essential oils of the plants were extracted using hydrodistillation method. CG and CG-MS were applied to analyze the chemical constituents of the essential oils and brine shrimp lethality test (BSLT) was used for the evaluation of general toxicity effects of the essential oils. Results: A total of 46 compounds were identified in the plants essential oils, among them β-caryophyllene (25.7%) and germacrene D (19.5) in P. olivieri and germacrene D (17.2%) and γ-elemene (15.4%) in P. persica were the main compounds. The essential oils of P. olivieri and P. persica exhibited a moderate toxicity activity (LD50: 24.2 ± 0.5 and 41.6 ± 0.8 μg/ml, respectively) in brine shrimp lethality test compared to podophyllotoxin (LD50: 2.8 ± 0.3 μg/ml). Conclusion: The results of present study report essential oils of P. olivieri and P. persica as two sesquiterpene rich oils with the moderate toxic activity. The chemical constituents of the analyzed essential oils were also found to be different from those reported from other regions of Iran, which may be due to the existence of possible different chemotypes between the populations of these two species.