Chemical composition and biological potentials of Lebanese Cupressus sempervirens L. leaves extracts

The essential oils and defatted ethanolic extracts isolated from Cupressus sempervirens L. leaves collected from two geographically distinct regions in Lebanon; Beit El-Dein (mountain) and Jbeil (sea-side) were analysed for their chemical composition by GC/MS and qualitative phytochemical screening, respectively. These were then tested for their in-vitro antioxidant and antibacterial activities. Fourteen and eighteen compounds were identified in Beit El-Dein and Jbeil samples, respectively with α-pinene (45.69-20.97%) and δ-3-carene (24.55-16.7%) representing the major constituents. C. sempervirens L. ethanolic extracts were able to reduce the stable radical 1,1-Diphenyl-2-picrylhydrazyl (DPPH) reaching 50% reduction with IC50 values equal to 113.17 and 155.75 μg/ml, respectively. These results positively correlated with the high phenol (77.4-66.4 mg gallic acid equivalent/g dry weight) and flavonoid (3.8-2.8 mg rutin equivalent/g dry weight) contents in both samples, respectively. Regarding the in-vitro antibacterial activity, essential oils exhibited a stronger potential mainly towards the Gram-positive bacteria Staphylococcus aureus compared with the ethanolic extracts as this was revealed by higher diameters of inhibition zone ranging between 7 and 12.3 mm and minimal inhibitory concentrations equal to 15.62 μl/ml. The results obtained from this study show that the Lebanese Cypress may be used as a good source of natural food preservatives and as drugs for various ailments.\r\n\r\n\tKey words: Lebanese Cupressus sempervirens L., essential oil and ethanolic extract, antioxidant, antibacterial activities.