ANTIMICROBIAL POTENTIAL OF ALKALOIDS AND FLAVONOIDS EXTRACTED FROM TAMARIX APHYLLA LEAVES AGAINST COMMON HUMAN PATHOGENIC BACTERIA

Background: Alkaloids and flavonoids are secondary metabolites extracted from different medicinal plants. Tamarix aphylla a traditionally valuable medicinal plant; was used for the extraction of alkaloids and flavonoids in order to evaluate their antibacterial activity. Methodology: The leaves of the plant were collected from district Kohat, Pakistan, and their alkaloids and flavonoids were extracted with ethanol and methanol, respectively. Four bacteria i.e. Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa) were selected for the biological screening of these phyto-constituents. Results: The concentration of alkaloids was found to be more in the leaves of Tamarix aphylla than flavonoids. The extracted phytochemicals showed varied inhibition zones against tested bacterial isolates. Alkaloids showed highest inhibitory activity against Staphylococcus aureus (14 +/- 0.6 mm) followed by Pseudomonas aeruginosa (13 +/- 0.7 mm). Conversely, flavonoids showed the highest inhibitory affect against Salmonella typhi (17 +/- 0.7 mm) followed by Staphylococcus aureus (14 +/- 0.7 mm). However, both extracts showed the lowest inhibitory effects against Escherichia coli. Conclusions: It was concluded that the alkaloids and flavonoids from Tamarix aphylla leaves have antimicrobial potential against common human bacterial pathogens. However, flavonoids were found to be more active phytochemical against tested bacterial strains as compared to alkaloids.