PHYTOCHEMICAL ANALYSIS OF GARLIC (ALLIUM SATIVUM), TURMERIC (CURCUMA LONGA) AND GINGER (ZINGIBER OFFICINALE ) AND THEIR SYNERGISTIC ANTIBACTERIAL ACTIVITY ON E. COLI

ABSTRACT This study investigated the phytochemical constituents and antibacterial activity of aqueous extracts of garlic (Allium sativum), turmeric (Curcuma longa), and ginger (Zingiber officinale), as well as their synergistic effects against Escherichia coli. Fresh plant samples were collected, processed into powdered form, and extracted using aqueous methods. Phytochemical screening revealed the presence of important secondary metabolites including flavonoids, tannins, phenolics, saponins, and alkaloids, though in varying amounts among the three plants. Antibacterial activity was assessed through the agar well diffusion method. The results showed that garlic exhibited the highest inhibitory effect against E. coli with a zone of inhibition of 14 mm, while turmeric and ginger showed no activity in aqueous form. Among the combined extracts, only the mixture dominated by garlic (1:1:2 ratio of ginger, turmeric, and garlic) demonstrated moderate inhibition (12 mm), while other ratios showed no measurable activity. These findings suggest that garlic possesses strong antibacterial potential compared to turmeric and ginger under aqueous extraction conditions. The limited synergy observed highlights the influence of extract ratios and solvent type on antimicrobial effectiveness. This study concludes that garlic remains a promising natural antimicrobial agent and recommends that future research employ organic solvents, quantitative synergy evaluation, and advanced phytochemical profiling. The results contribute to the growing evidence supporting plant‑based alternatives in addressing the challenge of antimicrobial resistance.