Asian Journal of Microbiology, Biotechnology & Environmental Sciences Paper

THE ANTIBACTERIAL PROPERTY OF TITHONIA DIVERSIFOLIA (WILD SUNFLOWER) EXTRACT FROM BAGUIO-BENGUET AREAS IN THE PHILIPPINES, IN RESPONSE TO EXPOSURE TO VEHICULAR TRAFFIC

ROSEMARY M. GUTIERREZ, KAREN BALLADA AND MELBA PATACSIL

Abstract

The spread of multiple drug resistance and emergence of new diseases have encouraged scientists to constantly search for natural products as source of new drugs. We investigated the antimicrobial properties of Tithonia diversifolia plants growing in four sites in the Baguio - Benguet areas, in the northern part of the Philippines that were exposed to vehicular traffic and compared it to sites that were not exposed to vehicular traffic. Laboratory based microbiological tests such as the disc diffusion assay and the determination of minimum inhibitory concentrations (MICs) using the broth dilution method, confirmed that the sunflower extracts from our four study sites gave varying degrees of antibacterial activity ranging from partially active, to active, against both gram negative and gram positive test microorganisms. Results of qualitative phytochemical screening of T. diversifolia leaf extracts from the study sites revealed the presence of steroids, saponins, tannins and polyphones as well as alkaloids which might be responsible for this broad antibacterial activity. However, our statistical analyses revealed a general trend that the antibacterial activity of the plant extract from BGH, the site most exposed to vehicular emissions was significantly higher than the rest of the plant extracts used in this study. Interestingly, the extracts from BGH and UP Drive, the sites more exposed to vehicular traffic were the extracts that were positive for alkaloids. This might be the response of the sunflower plant under stressful conditions. Based on these results, it might be that factors like geographical location along with pollution exposure have an effect on the antibacterial property of the wild sunflower plant. The combined mechanisms of action of all the different phytochemical compounds, including the presence of alkaloids plus other factors like soil nutrients and airquality might be the factors responsible for its high or active antibacterial activity.