Chemical Composition, Antimicrobial, Antiparasitic, and Cytotoxic Activities of Rhanterium intermedium Pomel Leaves Essential Oil

This study evaluates the chemical composition, antimicrobial, antiparasitic, and cytotoxic activities of essential oil extracted from Rhanterium intermedium Pomel (EORI) leaves. The chemical composition of the essential oil was analyzed by GC/MS analysis. In addition, the antimicrobial capacity of EORI against five pathogenic bacteria and two yeast strains was determined by disk diffusion and broth microdilution methods. Alamar Blue® assay was used to evaluate the antiparasitic potential of EORI against epimastigotes forms of Trypanosoma cruzi, trophozoïtes forms of Acanthamoeba castellanii Neff., and promastigotes forms of Leishmania amazonensis and Leishmania donovani. The same assay was used to assess the cytotoxicity effect of oil against murine macrophage J774. A1 cell line. GC/MS results showed that the EORI comprised 22 compounds, representing 97.99% of the total composition. The main constituents of EORI were camphene (32.08%), myrcene (13.86%), α-pinene (11.29%), sabinene (5.85%), and β-pinene (5.73%). Additionally, a significant antibacterial effect was recorded against Escherichia coli with MIC inferior to 14.78 mg/mL. Concerning the antifungal activity, EORI showed a remarkable efficiency against the two tested Candida albicans strains (MIC = 14.78 mg/mL). The EORI showed promising antiparasitic activity against epimastigotes forms of Trypanosoma cruzi (IC50 = 07.21 ± 0.09 μg/mL) and low cytotoxicity levels on murine macrophages (LD50 = 47.91 ± 3.61 μg/mL). Overall, it was shown that our tested essential oil possesses potential antimicrobial and antiparasitic capacities; also, it is considered safe to use. Further detailed investigations are needed to ensure EORI as a novel source of alternative drugs for microbial and parasitic diseases.