Screening of Antioxidant, Antibacterial and Antileishmanial Activities of Salvia officinalis L. Extracts from Morocco

Abstract

Aims: The aim of this study was to evaluate in vitro antioxidant and antimicrobial activities of organic extracts from Salvia officinalis L. (Lamiaceae) collected in the province of Ouezzane. Study Design: Evaluation of in vitro antimicrobial and antioxidant activities of extracts and determination phenolic contents. Place and Duration of Study: After plant collection from the Province of Ouezzane, further work was carried out in Parasitology Laboratory of the National Institute of health and Laboratory of Biochemistry-Immunology, Faculty of Science, Mohammed V University of Rabat, Morocco from Novembre 2015 to Mai 2016. Methodology: The antioxidant activity was evaluated using DPPH scavanging assay. The antibacterial activity was tested against three reference strains (Staphylococcus aureus, Escherichia coli and Listeria monocytogenes serovar) by the diffusion method and the minimum inhibitory concentration (MIC) by microtitration assay. The antiparasitic activity was tested against Leishmania major using MTT (3- (4.5-dimethylthiazol- 2yl) -2.5-diphenyltetrazolium bromide) assay. The levels of polyphenols and flavonoids extracts were estimated by colorimetric assay. Results: The methanol extract has shown a significant ability to trap the radical DPPH (IC50=65.655 µg/ml) compared to n-hexane and ethanol extracts. This value is higher than that of ascorbic acid (13.198 µg/ml) and Trolox (22.484 µg/ml) used as standards. The three extracts tests revealed the inhibitory power of three bacterial strains with a significant difference in the diameters of inhibition. The largest area was registered by the hexane and methanol extracts against S. aureus (22±8 mm), while the weakest area was 11±0.22 mm expressed by the ethanol extract against E. coli and the methanol extract against L. monocytogenes. The antileishmanial activity was moderate with a value of cytotoxicity (IC50) above 1 mg / ml. The extracts showed high concentrations of polyphenols and flavonoids, while biological activities were not very high when correlated with these levels. Conclusion: These results will be completed by the determination of the active component and the extracts will be tested on other biological systems namely antifungal and antitumor activities.