Antibacterial activity and preliminary phytochemical screening of crude leaf extracts of Mussaenda philippica cultivars
The primary objective of this study was to determine the antibacterial activity and screen for possible secondary metabolites present in the methanolic extract of Mussaenda philippica and its cultivars: M. philippica cv. Aurora, M. philippica cv. Hilaria, and M. philippica cv. Luz. In this study, the methanolic extracts were tested for the following secondary metabolites: tannins, flavonoids, alkaloids, steroids, and saponins. The antibacterial activity of the crude leaf extracts were tested against representative gram-positive bacterium (Bacillus subtilis and Staphylococcus aureus) and gram-negative bacterium (Escherichia coli). All the extracts exhibited an inhibition against the representative microorganisms. M. philippica crude extracts had the highest antibacterial activity against E. coli and B. subtilis at 76% (375 mg/1.25 mL) and 25% (150mg/1.75mL) concentration respectively. M. philippica cv. Aurora had the largest antibacterial activity against S. aureus at 75% (725mg/1.25mL) concentration. The study showed that the phytochemicals present in the crude leaf extract could have contributed to its reported antibacterial activity.