Phytochemical screening and antimicrobial activities of hydroethanolic extracts from leaves and roots of Cochlospermum planchonii (Bixaceae)

Abstract

Cochlospermum planchonii is traditionally used in Togo in treating several diseases, including burn wounds which achievement requires anti-infective and good cicatrisation processes. This study aims to evaluate the antimicrobial properties of hydroethanolic extracts from leaves and roots of C. planchonii and its phytochemical composition. Five (05) bacterial strains were suspended in liquid media with plant extracts at various concentrations and then spread, after 24 h incubation, on solid media. The minimum inhibitory (MIC) and minimal microbicidal (MMC) concentrations were assessed. Phytochemical characterization tests were performed and flavonoids, tannins and total phenol contents were also determined. Hydroethanolic extracts from the leaves and roots of C. planchonii were active on all the germs tested, with MICs ranging from 0.782 to 50 mg/mL and MMCs ranging from 1.563 to 100 mg/mL. The bests activities were recorded with root extract against Staphylococcus aureus: MIC=0.782 mg/mL and MMC =1.563 mg/mL. The MMC/MIC ratios are all equal to 2, indicating that both roots and leaves have bactericidal activities rather than inhibitory activities. Phytochemical tests have demonstrated the presence of metabolites such as flavonoids, tannins, carbohydrates, sterols, triterpenes, saponosides, and an absence of alkaloids. Total phenols, tannins and total flavonoids amounts found were respectively 85.466 ± 0.289; 33.566 ± 0.503; 218.333 ± 0.577 µgRE/mg in root extracts, and 75.833 ± 0.289; 26.533 ± 0,053; 183.666 ± 0.577 µgRE/mg in leaf extracts. Both root and leaf hydroethanolic extracts of C. planchonii could be potential natural antimicrobial remedies.  Key words: Phytochemical screening, antimicrobial activity, Cochlospermum planchonii, flavonoids, tannins.