Assessment of Some Biological Activities of Eucalyptus blakelyi Maiden Using the Essential Oil, Methanolic and Aqueous Extracts

Several species of Eucalyptus are used in folk medicine as an antiseptic, anti-inflammatory, and against respiratory infections, such as colds, sinus congestion and influenza. These species have shown potential antioxidant properties in addition to antimicrobial activities. In the present paper, we were interested in Eucalyptus blakelyi Maiden, a species belonging to the Myrtaceae family. Our study can be considered as the first detailed report on the chemical composition, antioxidant and antimicrobial activity of different extracts. The aim of the current study is to evaluate the biological activities of essential oils, methanolic and aqueous extracts of this plant. The present work was realized on leaves collected from National Institute for Forest Research (INRF) of Bainem (Algiers, Algeria), and the results showed that essential oil's yield obtained by hydrodistillation was 2.13 %. Actually, 15 compounds were identified by GC-MS profile, and the major compound was 1.8-cineole with 62.74 %. Indeed, the antiradical activity using the DPPH method has shown that methanolic and aqueous extracts had an interesting antioxidant ability with an IC50 of 0.33 and 0.39 mg/ ml respectively. The antimicrobial activity of the essential oil, methanolic and aqueous extracts on eleven microbial strains was evaluated using the aromatogram method. Thus, the methanolic extract proved to be the most active compared to the aqueous extract and the essential oil by inducing a maximum inhibition zones of 19.66 mm for Staphylococcus aureus ATCC29213 and 25.66 mm for Candida albicans. The results suggest potential applications of essential oil in food and extracts in pharmaceutical industry.