Effect of long-term storage of Artemisia dracunculus L. essential oil on antioxidant capacity and LD50 value

Herbal medicines are natural and safe; however, side effects can occur following excessive use of them. This research was aimed to investigate the acute toxicity and antioxidant activity of the essential oil of Artemisia dracunculus L. The essential oil of A. dracunculus (EOAD) was extracted by Clevenger apparatus using hydrodistillation. Two types of essential oil were studied including fresh and old oil (kept in laboratory conditions for three months). All protocols were tested for both fresh and old oil. The LD50 was calculated based on Lorke’s method using Probit Analysis and maximum Likelihood method with MINITAB software. To induce acute toxicity, appropriate concentrations of essential oil (10, 100, 1000, 1600, 2900 and 5000mg/kg of EOAD) were given orally and intraperitoneally. The antioxidant activity of EOAD (1-32mg/ml) was measured by two DPPH and ABTS assays. The oral LD50 values were greater than 5000 mg/kg and 3801.33mg/kg for fresh and old EO, respectively. When fresh and old EO administered intraperitoneally, the LD50 values were calculated to be 4810.06mg/kg and 3013.33mg/kg, respectively. The fresh essential oil showed higher antioxidant activity as compared with the old essential oil in both DPPH and ABTS methods. Our results clearly indicate that the essential oil of this plant is non-toxic and contains antioxidant compounds that support the use of tarragon in traditional medicine.