Biochemical Effects of the Saharan Myrtle

The first aim of this study is to evaluate the in vitro antimicrobial activity of the essential oil and two extracts of Saharan myrtle: Myrtus nivellei Batt & Trab. For this purpose, paper disc-diffusion method and micro-dilution test were used. As far as the antimicrobial activity is concerned the essential oil exhibited higher ones against S. epidermidis (MIC=0.28mg/ml), S. typhi (MIC=0.56mg/ml), E. coli (MIC=1.125mg/ml) and S. aureus (MIC=1.125mg/ml). However, the alcoholic extracts exhibited a good antimicrobial activity against S. aureus (MIC=2.25mg/ml) and C. albicans (MIC=4.5mg/ml). The samples were also subjected to screening for their possible free radical scavenging activity by using DPPH-test and β carotene-linoleic acid assays. In the first case, the free radical scavenging activity of ethanolic extract (IC50=0.59mg/ml),) was superior to the methanolic one (IC50=0.98mg/ml), while the oil was less effective. In the case of the linoleic acid system, oxidation of the linoleic acid was effectively inhibited by both the alcoholic extracts, but the ethanolic extract was the best with 93.5% inhibition, that is close to the synthetic antioxidant BHT used as positive control.