Chemical Composition, Antioxidant and Inhibitory Effect of Cupressus sempervirens Essential Oils and Methanolic Extract on Beta-lactamase producing Isolates

Abstract

The Jordanian endemic medicinal plant, Cupressus sempervirens was obtained from Dhana Natural Reserve, Al-Tafilah, Jordan to investigate its antibacterial and antioxidant activities. The procuring of essential oil was made by processing of dry leaves of C. sempervirens using steam-distillation method giving 0.26% (w/w) yield. The analysis of obtained EO for its chemical constituents, was achieved by GC-MS. The equivalent of 94.02% of the entire EO has been extracted and consists of twenty-two compounds. The characterization of EO was made by their presence of three groups of chemical compounds namely Sesquiterpene hydrocarbons (71.0%), Oxygenated sesquiterpenes (11.5%) and Monoterpenes hydrocarbons (10.6%). The major constituent was germacrene-D (14.2%) along with the d-cadinene (11.0%), ß-pinene (10.0%) and isocedrol (9.8%). This conferring a chemotaxonomic value as well as a higher degree of polymorphism in the occurrence of these compounds in C. sempervirens as compared with the same species in different location worldwide. The efficiency of methanol extract and essential oil as antibacterial was evaluated against nine bacteria, using disc diffusion and MIC methods. Results showed that the methanol extract at 2000µg/disc of C. sempervirens caused the growth inhibition of Bacillus subtilis, Micrococcus luteus, Staphylococcus epidermidis and Staphylococcus aureus and producing inhibition zone ranges between 12-15mm. The MIC values recorded by essential oils of C. sempervirens were as follow: S. epidermidis and S. aureus (370µg/mL), Escherichia coli and Enterobacter aerogenes (1000µg/mL), Pseudomonas aeruginosa (2000µg/mL) and M. luteus, Klebsiella pneumonia and Salmonella typhi (3000µg/mL). In the present study, C. sempervirens extract exerted antioxidant efficiency with an IC50 value of 27.31µg/mL.