Chemical Screening and Antibacterial Activity of Honey Produced in Benin

Objectives: This study aimed to evaluate the antibacterial activity of honeys produced in Benin against selected pathogenic strains and to determine their composition in plant secondary metabolites with known antibacterial activity. Methods: A total of 60 honey samples were collected in the country’s three phyto-geographical zones during the dry and rainy seasons. Chemical screening for secondary metabolites was performed on raw undiluted honey. Undiluted honey (100%) and honey diluted at 75%, 50% and 25% were used to assess their antimicrobial effect in vitro on six reference strains (ref-S) and six meat isolated staphylococcal strains (meat-S). MIC and MBC were also determined. Results: Chemical screening of undiluted honeys revealed that tannins, flavonoids, leuco-anthocyanins, alkaloids, coumarins and reducing compounds were preponderant irrespective of season of production. Only the undiluted honeys were effective at inhibiting some of the strains, namely four ref-S (P. mirabilis, S. aureus, S. epidermidis and S. oralis) and three meat-S (S. aureus, S.lentus, S. xylosus). Season of honey production had a significant effect on mean Inhibition Zone Diameter (IZD) for ref-S. For these strains, greater IZD were found for honeys produced during the dry season, except for S. aureus. For meat-S, in contrast, zone of production had a significant effect, with greater IZD for honeys from the Sudanian zone. Strains differed significantly in their sensitivity assessed by IZD: across all honeys, the greatest IZD were against P. mirabilis and meat-S:S. aureus and S. lentus. MIC varied greatly among honeys and strains. For meat-S, the effects of production zone and season were significant and the highest MIC were found for honeys from the Sudanian zone. Application/Improvements: Benin honey has bacteriostatic properties against several pathogens, and influenced by season and zone of production. Further studies are warranted to substantiate these new findings and identify the active principles.