Total Phenolic Content, Antioxidant Activity and In vitro Cytotoxicity of the Essential Oil of Jurinea leptoloba DC

The essential oil from the aerial parts of Jurinea leptoloba DC., collected from Shiraz (South of Iran), was investigated for total phenolic content (TPC), antioxidant and cytotoxic effects. TPC of J. leptoloba oil was determined to be 16.53 ± 5.69 μg gallic acid equivalent/mg sample (μg GAE/mg oil) using the Folin-Ciocalteau assay. The ferric reducing power of the oil was determined 0.117 ± 0.01 GAE (mg/g). J. leptoloba oil exhibited a dose-dependent scavenging of DPPH, with an IC50 value of 24.50 mg/ml. Antioxidant activity percentage of the essential oil of J. leptoloba determined by β-carotene bleaching test revealed less potential than both standards BHT and BHA (62.01 ± 2.45%, 2.5 mg/ml oil). Cytotoxicity was measured using a modified MTT assay. IC50 values for HeLa and lymphocyte cells were calculated to be 290.76 and 2900.97 μg/ml, respectively. The results suggest application of J. leptoloba essential oil as a moderate antioxidant and anticancer agent.