In-Vitro Evaluation Of Antibacterial Properties Of Euphorbia Hirta Against Selected Multidrug-Resistant Bacteria In Ghana.

Abstract

Background: Treatment of infections is an important area of public health concern as the prevalence of multidrug-resistant (MDR) bacteria is on the rise. MDR bacteria are associated with high morbidity and mortality worldwide. Medicinal plants including Euphorbia hirta have shown effectiveness in the treatment of infections and have been one area of interest worldwide for the treatment of diseases due to their high antimicrobial properties against MDR bacteria. In Ghana, the continuous spread of MDR bacteria has resulted in prolonged illness, increased healthcare costs and heightened fatalities which can suddenly cripple the country’s economy. One way to reduce the burden of MDR bacteria is to screen for new classes of antimicrobials from natural products and medicinal plants. Thus, this research aimed to evaluate the antimicrobial properties of E. hirta against selected MDR bacteria in Ghana. Methodology: Five solvents systems (methanol, distilled water, ethyl acetate petroleum ether and dichloromethane) with varying polarities were used to extract E. hirta via cold and Soxhlet extraction methods. The agar-well diffusion method was used to determine the antimicrobial activity of the various extracts against some selected MDR bacteria. Column chromatographic technique was used to the separate most potent crude extract into fractions and their antimicrobial activity were determined. Fractions that showed antimicrobial activity were further purified using column chromatography. Purified fractions were analyzed for the functional groups of compounds present using gas chromatography mass spectrometer (GCMS). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of crude ethyl acetate extracts and active fraction was determined. Results: Results from this study showed that, soxhlet maceration process had higher yield than cold maceration but the antimicrobial activity of extracts from both methods were the same. The University of Ghana http://ugspace.ug.edu.gh xvi

Antimicrobial susceptibility test (AST) results revealed that K. pneumoniae isolates. recruited in the study were resistant to all extracts used. Furthermore, all test organisms were resistant to dichloromethane and petroleum ether extracts. Out of the 15 test organisms used, methanol and aqueous extracts were potent against 5 test organisms. Phytochemical analysis revealed the presence of phytoconstituents such as reducing sugars, phenolic compounds, saponins, flavonoids, anthracenosides and phytosterols. GC-MS analysis shows that 1,2,3-Benzenetriol is the probable sugars present in the active fraction. MIC and MBC results indicated that ethyl acetate extracts and the active fraction had the same MBC values with 3.13 mg/ml as their lowest MBC concentration. The MIC value recorded for crude ethyl acetate was between 50- 6.25 mg/ml whiles that of the active fraction (CF5) was between 50 -12.5 mg/ml. Conclusion; Polar extracts of whole E. hirta plant have antimicrobial activity with ethyl acetate extracts being the highest. The plant has the potential to be used as an antimicrobial agent. Therefore, in-vivo studies should be conducted using different polar solvents to extract the whole plant of E. hirta to exploit its antimicrobial activity in living thing.