Comparative Antibacterial Activity of Ethanolic Extracts of Fenugreek (Trigonella foenum‑graecum L.), Cinnamon (Cinnamomum sp.) and Carob (Ceratonia siliqua L.) Against Escherichia coli and Staphylococcus aureus

Background & Aim: Plant-derived antimicrobials offer promising alternatives amidst escalating antibiotic resistance.This study compares the in-vitro antibacterial efficacy of fenugreek seed, cinnamon bark and carob pod ethanolic extracts against Escherichia coli and Staphylococcus aureus.Methods: Shade-dried market samples were powdered and extracted with 50 % ethanol (1 : 10 w/v).Antibacterial activity was quantified by cup-plate agar diffusion (inhibition-zone diameter, IZD) and viable-count reduction assays across five extract concentrations (0 - 100 %).Growth media: nutrient agar (NA) for S. aureus and eosin-methylene-blue (EMB) agar for E. coli.Colony counts were taken at 6, 12, 18 and 24 h; IZDs at 2-day intervals up to day 8. Statistical significance was assessed by one-way ANOVA ( = 0.05).Results: Fenugreek exhibited the strongest bactericidal effect, reducing E. coli colonies from 90 4 to 1 0.2 CFU plate at 100 % extract and producing a maximal IZD of 11.2 0.4 mm.Cinnamon showed moderate activity (IZD = 11.9 0.3 mm; 97 % CFU reduction), attributed to trans-cinnamaldehyde. Carob was least active, yet still achieved a 71 % reduction in E. coli CFU and IZD = 12.7 0.5 mm at 100 % extract.Similar rank order was observed against S. aureus, with fenugreek and cinnamon demonstrating comparable potency (IZD 10-12 mm), whereas carob required higher concentrations for equivalent effect.Dose-response plots revealed IC values of 38 %, 52 % and 67 % (v/v crude extract) for fenugreek, cinnamon and carob respectively against E. coli.Conclusions: All three Sudanese botanicals possess measurable antibacterial activity, with fenugreek and cinnamon outperforming carob.Synergy between saponins, tannins and cinnamaldehyde likely underpins the observed effects.Results warrant bio-guided fractionation and combinatorial testing with conventional antibiotics.