Combined Antibacterial Effects of Honeybee (Apis mellifera) and Garlic (Allium sativum) Extracts against Standard and Clinical Pathogenic Bacteria

Abstract

Among natural antimicrobial substances, honey and garlic were widely used and investigated separately. But their synergistic antibacterial effect was not studied. The objective of this study was to investigate synergistic antimicrobial effect of combination of honey and garlic against pathogenic bacteria. The antimicrobial activity of mixture of honey and garlic, honey and garlic extract alone against Salmonella NCTC 8385, Listeria monocytogenes (ATCC 19116), Escherichia coli (ATCC 25922), Shigella flexneri (ATCC 12022), Shigella dysenteriae (clinical isolate), Salmonella typhi (clinical isolate), Staphylococcus aureus (ATCC 25923) and Streptococcus pneumonia (ATCC 63) were determined. Mean diameter inhibition zone of 125 mg/mL of a crude mixture of garlic and honey (28.88 mm) was significantly (P ≤ 0.05) greater than inhibition zone (24.77 mm) of chloramphenicol (30 µg). The minimum inhibitory concentration of mixture of honey and garlic (62.5 mg/mL) against tested bacteria was significantly (P ≤ 0.05) less than the MIC of garlic extract (70.31 mg/mL) and honey (101.56 mg/mL), separately. Mean value of MBC of mixture of honey and garlic (73.44 mg/mL) against tested bacteria was also significantly (P ≤ 0.05) lower than the MBC of garlic extract (125 mg/mL) and honey (171.86 mg/mL) alone. This implies that inhibition and bactericidal activity of mixture of honey and garlic extract against tested pathogenic bacteria was by far better than honey and garlic extract. There is a synergy effect of antimicrobial activity of combination of garlic and honey against pathogenic bacteria. Their synergistic effect against pathogenic bacteria leads to new choice for the treatment of infectious diseases.