Abstract

Objective: To evaluate the antiradical, antibacterial and antileishmanial properties of phenolic extracts of Centaurium erythraea (methanol: MECE, ethanol: EECE, n-hexane: HECE, ethyl acetate: EACE) from north-west of Morocco. Methods: The antiradical activity was evaluated using DPPH scavenging assay. The antibacterial activity was tested against four reference strains (Staphylococcus aureus, Escherichia coli, Listeria monocytogenes and Pseudomonas aeruginosa) using the well diffusion method. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined by microdilution assay. The antiparasitic activity was evaluated against Leishmania major, Leishmania tropica and Leishmania infantum using MTT (3-(4.5-dimethylthiazol-2yl)-2.5-diphenyltetrazolium bromide) test. The levels of polyphenol and flavonoid extracts were estimated by colorimetric assay. Results: The HECE extract has shown a significant ability to trap the radical DPPH [IC50 = (49.54 ± 2.43) μg/mL] compared to EECE, MECE and EACE. This value is significantly important compared than those of ascorbic acid [IC50 = (27.20 ± 0.17) μg/mL] and Trolox [IC50 = (43.72 ± 0.31) μg/mL] used as standards. The inhibitory activity of methanol, n-hexane and ethyl acetate extracts was especially remarkable (inhibition zone ≥ 14 mm) against all strains tested. The values of MIC and MBC have ranged from 0.25 to 8.00 mg/mL. Pseudomonas aeruginosa was the most resistant strains compared to all other tested bacteria, while Staphylococcus aureus was the most sensitive toward the tested extracts. The MTT based colorimetric assay has shown a reduced promastigotes viability on all strains tested. The best growth inhibition was observed with HECE against Leishmania tropica [IC50 = (37.20 ± 1.62) μg/mL] and Leishmania major [IC50 = (64.52 ± 2.20) μg/mL] compared to N-methyl Glucamine Antimoniate (Glucantime®) (IC50 > 500 μg/mL) used as control, after 72 h of treatment. Conclusions: Considering these results, Centaurium erythraea can be used as a source of novel antioxidant, antibacterial and antileishmanial compounds.

Authors and Affiliations