ANTIMICROBIAL AND ANTIOXIDANT ACTIVITIES OF CRUDE EXTRACTS OF STINGLESS BEE HONEY AND PROPOLIS ON SOME SELECTED HUMAN BACTERIAL PATHOGENS

Abstract

Stingless bees produce honey (locally named as tazma mar) and propolis that are different from the Apis mellifera honey and propolis in terms of composition. The aim of this study was, therefore, to evaluate the antibacterial and antioxidant activities of honey and propolis from stingless bee in vitro against selected human bacterial pathogens. The crude extracts of stingless bee honey and its propolis were prepared using absolute ethanol, methanol and distilled water. Total phenolic content, total flavonoid content and in vitro antioxidant activity were evaluated. Antimicrobial activities of the resulting extracts were determined by measuring zone of inhibitions on cultures of five selected pathogens using the disc diffusion method. The minimum inhibitory concentration and minimum bactericidal concentration of the honey and its propolis extracts against the same pathogens were determined using the broth dilution method. Ciprofloxacin and Dimethyl Sulfoxide were used as a positive and negative control against the test pathogens, respectively. The results showed that the highest total phenolic content of the methanoic extract of honey and the methanoic extract of its propolis was 0.84±0.01mg of Gallic acid equivalent / g and 0.87±0.03 mg of Gallic acid equivalent/ g, respectively. The highest total flavonoid contents recorded from the methanoic extract of honey and propolis was 0.47±0.01mg of Quercetin equivalent/g and 0.82±0.04 mg of Quercetin equivalent/ g, respectively. The in vitro antioxidant activities recorded from methanoic extract of honey and propolis was 58.80±0.71 mg of BHT equivalent /g and 98.05±0.87mg of BHT equivalent/g, respectively. In this study, the ethanoic, methanoic and aqueous extracts of honey and propolis at 100% concentration had the highest inhibitory activities against Salmonella Typhi, Bacillus cereus, Escherichia coli compared to the standard antibiotic Ciprofloxacin. Streptococcus pyogenes was the most affected by Ciprofloxacin among the test pathogens. The Gram negative S.Typhi was found to be totally resistant to Ciprofloxacin. The MIC of honey and propolis ranged from 0.625mg/ml to 10mg/ml and MBC from 2.5mg/ml to 40mg/ml. Further work is needed to know and characterize the pure chemical compounds of phytochemicals of the honey and propolis of stingless bee.