Ho Shing Yang Tiew Wah Peng Priya Madhavan, Mohamed Saleem Abdul Shukkoor Gabriel Akyirem Akowuah
Clinacanthus nutans is a medicinal herb found in South East Asia. It has been traditionally used for skin infections. Hence, this study aimed to investigate the antibacterial effect of C. nutans against selected bacteria. C. nutans leaf was extracted with methanol. The dried methanolic extract was qualitatively screened for the presence of phytochemicals and quantitatively analysed for total phenols and total flavonoids. The strains of Propionibacterium acnes (ATCC 11827), Staphylococcus aureus (ATCC 29213), Staphylococcus epidermidis (ATCC 12228), Bacillus cereus (ATCC 10876) and Escherichia coli (ATCC 25922) were selected for the study. The antibacterial effect was tested by microbroth dilution method in a 96-well microtiter plate and minimum inhibitory concentrations (MIC) were determined. The yield of methanolic extract of C. nutans leaves was 15.29 %w/w. Total phenolic content was 1.77±0.008 mg gallic acid equivalent/g. Total flavonoid content was 0.04±0.001 mg quercetin equivalent/g. Phytochemical screening revealed the presence of saponins, phenolics, flavonoids, diterpenes and phytosterols. The C. nutans extract exhibited antibacterial effect against Propionibacterium acnes (MIC > 12.5 mg/ml), Staphylococcus aureus (MIC 12.5 mg/ml), Staphylococcus epidermidis (MIC > 12.5 mg/ml), Bacillus cereus (MIC > 12.5 mg/ml) and Escherichia coli (MIC 12.5 mg/ml). Our study indicated that C. nutans possess significant antibacterial effect against S. aureus and E. coli. Further studies are required to identify the antibacterial compounds.
