Efficacy of the Essential Oils of Curcuma Longa and Syzygium Aromaticum against Bacteria Implicated in Diabetic Foot Ulcers

Diabetes mellitus is a metabolic disease and one of the most feared complications is diabetic foot ulcers (DFUs) resulting in amputation and gangrene arising from the action of pathogenic bacteria. This study investigated the efficacy of essential oil extracts of Curcuma longa (turmeric) and Syzygium aromaticum (clove) on bacteria implicated in DFUs. Essential oils extracted from Curcuma longa and Syzygium aromaticum were used singly and in combinations to determine their antimicrobial activities on bacteria isolated from DFUs (Salmonella paratyphi, Salmonella arizona, Pseudomonas aeruginosa, P. fluorecens, Citrobacter sp, Enterococcus fecalis, Enterobacter sp, Escherichia coli, Enterobacter cloacae, Proteus mirabilis, Proteus vulgaris, Staphylococcus aureus, Bacteroides fragilis, and Peptostreptococcus sp.). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were also determined. The zone of inhibition was highest in Proteus mirabilis (36.0 mm ± 1.0 mm) and lowest in Salmonella arizona (10.0 mm ± 1.0 mm). Clove essential oil had the highest activity against the selected bacteria (82.76%). Turmeric was able to inhibit 2.97% of the pathogenic bacteria. Combinations of clove and turmeric inhibited 82.76% of the isolates. The MIC and MBC ranged between 0.90% and 7.5% respectively. This study showed that terpenoid extracts of the selected plants are active against pathogenic bacteria isolated from DFUs while the high activity of Syzygium aromaticum (clove) extract could serve as a pointer towards the development of antimicrobial compounds of natural origin to combat drug-resistant pathogenic bacteria associated with diabetic foot ulcers.