2 research outputs found
In vivo antibacterial activity and biochemical effects of methanol extract of Annona muricata leaves against multidrug- resistant Salmonella Typhimurium in Wistar rats
No full textBackground: The increasing antibiotic resistance and paucity of new antibiotics has contributed greatly to the high morbidity and mortality of salmonellosis necessitating the search for alternative treatments. Annona muricata has shown promising activity against multidrug-resistant (MDR) Salmonella in vitro but in vivo studies are rare. This study evaluated the activity of A. muricata, against MDR Salmonella Typhimurium in vivo.
Methods: The minimum inhibitory concentration (MIC) of a methanol crude extract of A. muricata was determined by micro-dilution assay against a characterized MDR clinical S. Typhimurium strain. Wistar rats infected with 3 x 108 CFUs/mL of the MDR strain were treated with 50-200 mg/kg body weight of extract for 10 days. Faecal load of S. Typhimurium colonies was determined by the direct plate count technique on days 1, 5 and 10. Animals were sacrificed and blood was collected for biochemical analyses. Data were analysed using GraphPad Prism Software.
Results: The S. Typhimurium strain was multidrug-resistant and the extract recorded a MIC of 2 mg/ml The extract produced a significant (p<0.001) dose-dependent reduction in Salmonella colonies in faeces of treated rats with a 100% inhibition recorded at 200 mg/kg body weight on day 10. Liver and renal function tests did not indicate any abnormalities (p<0.05).
Conclusions: This is the first report of in vivo activity of A. muricata leaves against multidrug-resistant Salmonella. The high activity and lack of adverse toxicity supports it use in traditional medicine and hence is a potential treatment for resistant Salmonella infections.
Anti-Salmonella activity on multidrug-resistant strains and cytotoxicity of extracts and constituents of Garcinia brevipedicellata and Garcinia epunctata
No full textThe morbidity of Salmonella infections remains high partly due to emergence of multidrug-resistant (MDR) strains. Garcinia species have demonstrated activity against a wide range of infectious organisms including bacteria. Two species, Garcinia brevipedicellata and G. epunctata were investigated for activity against MDR clinical isolates of Salmonella. Methanol extracts of the leaves of both plants were serially re-extracted using ethyl acetate (EtOAc), acetone (Ace) and methanol (MeOH); and the three extracts tested for antibacterial activity by disc diffusion and microdilution methods, and cytotoxicity effects against monkey kidney epithelial (LLCMK2) cells. Five of eighteen pure compounds isolated, identified and tested for activity include β-sitosterol (1), stigmasterol (2), epunctosides A (3), B (4) from G. epunctata and brevipedicelone D (5) from G. brevipedicellata; among which three are new compounds (3, 4 and 5). The EtOAc extract of G. epunctata and brevipedicelone D (5), recorded maximum diameters of zones of inhibition of 18 and 17 mm respectively corresponding to moderate activity. All the four crude extracts recorded the lowest minimum inhibitory concentration (MIC) of 0.125 µg/mL, corresponding to high activity against MDR Salmonella isolates and control strains. Brevipedicelone D (5) showed moderate activity with the lowest MIC of 16 µg/mL. All the crude extracts and compound 5 were not cytotoxic (CC50 = 250 - 809µg/mL). Low minimum bactericidal concentrations (≤ 2 mg/mL) were recorded against most bacteria strains which may indicate bactericidal activity. This is the first report of moderate to high activity against MDR Salmonella and no cytotoxicity of the leaves and pure compounds from G. brevipedicellata and G. epunctata; hence, the leaves should be further investigated as a potential alternative treatment for infections of these strains and source of an antibacterial natural product lead
