Comparison of antibacterial Apis mellifera honey varietals from northeastern United States

Abstract

The demand for alternative medicine is increasing as more bacteria become resistant to antibiotics. Apis mellifera is a honeybee that feeds on nectar from a variety of plants, some of which have antibacterial properties. The objective of this study was to identify antibacterial honeys native to the northeastern USA. Six honey varietals were examined: black locust (Robinia pseudoacacia), buckwheat (Polygonum convolvulus), basswood (Tilia americana), blueberry (Vaccinium angustifolium), orange blossom (Citrus seninsis), and goldenrod (Solidago altissima). Well diffusion and zones of inhibition were used to examine the antibacterial properties of these varietals against Escherichia coli and Staphylococcus aureus. Three out of six honey varietals significantly inhibited bacterial growth. Basswood honey exhibited the greatest antibacterial effect on E. coli and S. aureus, inhibiting growth at 1% and 2% w/v, resulting in zones of inhibition of 30.3 ± 2.0 mm and 12.7 ± 0.6 mm, respectively. Six volatile compounds were identified using GC-MS. Four compounds were identified within blueberry honey (dodecane, methyl [4-(propan-2-yl)phenyl] carbonate, butan-2-yl heptanoate, and disalicylide), two were identified in goldenrod honey (ethyl 4-ethoxybenzoate and 9-methylphenanthrene), and one was identified in basswood honey (ethyl 4-ethoxybenzoate). Basswood, orange blossom, and goldenrod were as inhibitory or more inhibitory than the commonly used antibiotic tetracycline, which would suggest that these honey varietals should be further explored as a potential topical antibiotic.