Inhibitory effects of hydroethanolic extracts from three Cameroonian medicinal plants on proteins inflammation and growth of multi-resistant strains of Mycobacterium tuberculosis

The present work aimed to determine the phytochemical components and evaluate the in vitro anti-inflammatory and anti-mycobacterial effects of hydroethanolic extracts of Allium sativum L bulbs, Drypetes gossweileri S. MOORE stem-barks and Pentadiplandra brazzeana Baill roots against several resistant strains of Mycobacterium tuberculosis. The phytochemical screenings of extracts were carried out according the colorimetric and precipitation tests to reveal the presence of phytochemical compounds. The anti-inflammatory effects of extracts were evaluated using in vitro Bovine Serum Albumin denaturation and proteinase inhibitory action assays. The inhibitory parameters of hydro-ethanol extracts were evaluated by the microdilution method agaisnt Mycobacterium tuberculosis. The phytochemical screening of hydro-ethanol extracts revealed the presence of phenols, polyphenols, flavonoids, alkaloids, cathechic tannins, triterpens, steroids, anthocyanins and leucoanthocyanins. The anti-inflammatory activity of hydro-ethanol extracts of D. gossweileri, P. brazzeana and A. sativum have shown the inhibitory concentrations 50 (IC50) values ranging from 356.70, 183.30 and 226.30 mg/mL for BSA denaturation and 31.92, 33.62 and 56.93 mg/mL for proteinase inhibitory action respectively. The hydroethanolic extracts of D. gossweileri, P. brazzeana and A. sativum exhibited moderate and weak anti-mycobacterial activities with the minimum inhibitory concentrations (MICs) ranging from 312.5 to 2500 μg/mL. A. sativum hydro-ethanol extract has shown the highest anti-mycobacterial activity with MIC of 312.5 μg/mL against isoniazid resistant of M. tuberculosis and extremely resistant drug strain of M. tuberculosis. These results suggest that hydro-ethanol extracts of A. sativum, D. gossweileri and P. brazzeana are efficient against tuberculosis caused by multi-resistant Mycobacterium tuberculosis strains and are able to resorb the inflammation induced during infection. Keywords: Anti-inflammatory activity, Anti-mycobacterial effect, Hydroethanolic extracts, Medicinal plants, Phytochemical screening.