In vitro Antileishmanial Activity of Extracts from Endemic Moroccan Medicinal Plant Salvia verbenaca (L.) Briq. ssp verbenaca Maire (S. clandestina Batt. non L)

Aims: The aim of this study was to evaluate in vitro the antileishmanial activities of organic extracts (methanol, n-hexane and dichloromethane extract) from Salvia clandestina (Lamiaceae) used in Moroccan medicinal plant.

Study Design: Evaluation of in vitro antileishmanial activity of extracts and determination phenolic contents.

Place and Duration of Study: After plant collection from the region of Rabat-Morocco, 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 February 2015 to march 2016.

Methodology: The plant was extracted using organic solvents and using Soxhlet. The antileishmanial activity of extracts was tested against three leishmanial strains, Leishmania major, Leishmania tropica and Leishmania infantum in their promatigotes form, using MTT assay. The total phenolic content was assessed by the Folin-Ciocalteau assay and total flavonoid content was assessed by aluminium chloride (AlCl3) colorimetric assay.

Results: The MTT based colorimetric assay showed reduced promastigotes viability on the all strains tested. The best growth inhibition was observed with n-hexane and dichloromethane extracts of Salvia clandestina (IC50≤ 155.43 µg/ml) compared to N-methyl glucamine antimoniate (Glucantime®) (IC50>1000µg/ml) used as control, after 72 h of treatment. Phenolic content of S. clandestina extracts ranged between 107.52±3.12 and 74.41±4.96 mg GAE/g extract, and the flavonoid content ranged between 24.64±3.65 and 16.31±3.69 mg QE/g extract.

Conclusion: The current investigation reveals that S. clandestina extracts possess activity against three Leishmania species. S. clandestina need further investigation so that the pure bioactive antileishmanial compounds should be isolated with cost effective, promising results and less side effects.