In Vitro Antimicrobial Activity of <i>Plectranthus comosus</i> and <i>Allium sativum</i> Extracts Against <i>Salmonella typhi</i>

Salmonella typhi, a Gram-negative pathogen, causes typhoid fever, a significant health issue worldwide, especially in areas with poor sanitation and limited access to clean water. The rise of antibiotic-resistant S. typhi strains necessitates the exploration of alternative treatments. Herbal remedies, known for their antimicrobial and anti-inflammatory properties, are widely used in developing countries. This study investigates the antimicrobial activity of Plectranthus comosus and Allium sativum (garlic), both traditionally used for medicinal purposes. With the increasing resistance of S. typhi to conventional antibiotics, there is a pressing need to identify effective alternative therapies, particularly from plant-based sources. The antimicrobial activity of P. comosus and A. sativum extracts was evaluated using hexane, dichloromethane, ethyl acetate, methanol, and distilled water as solvents. The agar well diffusion method was used to assess antimicrobial activity, while the minimum inhibitory concentration (MIC) was determined to evaluate the efficacy of the extracts. Both P. comosus and A. sativum exhibited significant antimicrobial activity against S. typhi. The combined extracts showed a synergistic effect, enhancing antimicrobial activity compared to individual extracts. Methanol and dichloromethane were found to be the most effective solvents for extracting bioactive compounds responsible for the inhibitory effects. While the combined extract was less potent than ciprofloxacin, it demonstrated potential as a complementary therapy, especially in cases of antibiotic resistance. This study highlights the significant antimicrobial properties of P. comosus and A. sativum, particularly when combined, against S. typhi. The synergistic effect between the two plants suggests their potential as natural alternatives to conventional antibiotics, particularly in combating resistant strains. Further research should focus on identifying the specific bioactive compounds responsible for the observed synergy and conducting in vivo studies to evaluate safety, dosage, and clinical efficacy. Additionally, broader bacterial strain testing and toxicity assessments are essential to confirm the safety and broader applicability of these plant-based therapies. This study contributes to the growing need for alternative treatments for drug-resistant S. typhi, offering a biochemical basis for exploring plant-based antimicrobial therapies in combating antibiotic resistance.