In-Vitro Investigation of Antimicrobial Effect of Bark Root Extracts of Solanum Incanum and Croton Macrostachyus

Abstract Background: The increasing antibiotic resistance exhibited by pathogenic microbial infectious agents has led to the screening of several medicinal plants for their potential antimicrobial activity. An in vitro experimental investigation was conducted with the aim to evaluate antibacterial effect of bark root extracts of S. incanum and C. macrostachyus against S. aureus and E. coli. It was experimental study from January 2019 to November 2019 in Jimma University. The crude extracts of S. incanum and C. macrostachyus were done using petroleum ether, ethanol and distilled water by maceration methods. The antibacterial activity tests were assessed using agar well diffusion and minimum inhibition concentration methods. Results: C. macrostachyus bark rout ethanol extracts have shown an antibacterial effect against E. coli and S. aureus with maximum mean zone of inhibition of 15±0.58 mm and 17.33±0.89 mm respectively. In case of S. incanum it is also the ethanol extract that showed highest mean zone of inhibition of 22.67±0.89 mm and 22.33±0.89 mm against E. coli and S. aureus respectively. The positive control Gentamicin (10µ gm/disc) inhibited the growth of E. coli and S. aureus with recorded mean zone of inhibition about 23 ±0.58 mm and 24.67± 0.33 mm respectively. Therefore the ethanol extract of Croton macrostachyus and S. incanum showed minimum inhibitor concentration against S. aureus and E. coli than other solvents. Conclusion: Bioactive compounds of medicinal plant extracts have been used to overcome the challenges of antimicrobial resistance. The current experimental study showed that, the bark root extract of Solanum incanum and Croton macrostachyus have high potent of antibacterial activities against E. coli and S. aureus . This study therefore substantiates the use of Solanum incanum and Croton macrostachyus as an antimicrobial medicinal plant.