PHYTOCHEMICAL COMPOSITION AND ANTIBACTERIAL EFFECT OF Sida cuneifolia Vollesen ON SELECTED PATHOGENIC BACTERIA

Abstract

During the last decade, the use of traditional medicine has escalated globally. With the increase in antibiotic resistance, there is need for increased search for new plants that possess antimicrobial properties. Sida cuneifolia is a woody shrub that is used traditionally to treat several ailments caused by enterobacteriaceae and Staphylococcus spp, yet its medicinal properties are not well researched. Conventional treatment of enteric and opportunistic infections is by use of antibiotics but of late these causal microorganisms have developed resistance to most antibiotics. The objectives of this study were to determine the efficacy of S. cuneifolia plant parts against E. coli, Shigella, S. aureus and Salmonella typhi, evaluate the best extraction solvent and to determine the various phytochemicals found in the plant, in the lab. The Kirby baueur disk method was used to determine the efficacy of the extract. The phytochemicals in the plant were determined using Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC). Leaves were the most effective plant part against the pathogens followed by the stems. Generally, ethanol extracts exhibited higher activity against S. aureus, S. typhi and Shigella compared to the aqueous extracts. However, leaf aqueous extracts had the highest antimicrobial activity against S. typhi. The roots and stem ethanol extracts exhibited the lowest minimum inhibitory concentration (MIC) of 0.001 μg/ml each against S. typhi. The leaves ethanol extracts had a MIC of 0.01 μg/ml against Shigella and S. aureus. This was similar to the leaf aqueous extracts against S. typhi, stem ethanol extracts against Shigella and root ethanol and aqueous extracts against S. aureus and Shigella. The TLC results indicated that all the tested phytochemicals were present in the leaf, root and stem ethanol extracts except alkaloids in the stem. The alkaloids and flavanoids were absent in the aqueous extracts. Further analysis using HPLC showed caffeic acid, gallic acid and flavanoles 4’OH,5’OH as the common phytochemicals present in all the extracts. Sida cuneifolia has antimicrobial activities against S. aureus, S. typhi and Shigella. Ethanol leaf extracts of the plant may be exploited for treatment of infections caused by the three microorganisms.