The effects of bee species and vegetation on the antioxidant properties of honeys produced by Afrotropical stingless bees (Hymenoptera, Apidae, Meliponini)

Abstract

Stingless bee honey is widely utilized as a traditional medicine in tropical and subtropical regions. The rich diversity of stingless bees and floral resources in the African tropics presents an opportunity for the production of honeys with diverse therapeutic properties. This study investigated the influence of bee species and vegetation on the antioxidant properties of stingless bee honey. Honey samples were collected from six species of Afrotropical stingless bees in six different vegetation zones of Tanzania, and tested for phytochemical composition and antioxidant activity. Our findings demonstrate that the antioxidant properties of stingless bee honey were influenced by both bee species and vegetation, with the former exhibiting a stronger effect. Honeys produced by different stingless bee species varied significantly in all of the assayed parameters, whereas honey samples from different vegetation zones differed in 80% of the parameters. Further, there was a clear separation of honey samples based on bee species on the non-metric multidimensional scaling (NMDS) and principal component analysis (PCA) plots which suggests that the antioxidant properties can be used as markers for discriminating honeys produced by different bee species. The studied stingless bee species across different vegetation zones produced honeys with remarkable phenolic content (46.80–365.17 mg GAE/100 g), flavonoid content (27.49–210.83 mg QE/100 g), vitamin C (7.42–60.50 mg/100 g), radical scavenging activity (32.75–92.50%) and ferric reducing antioxidant power (68.11–221.23 μmol Fe (II)/100 g). Stingless bee honey presents a promising niche for pharmaceutical research and innovation, particularly for Dactylurina schmidti honey which demonstrated exceptional levels of phytochemicals and antioxidant activity. We encourage future studies to investigate the biologically active components in honeys produced by Afrotropical stingless bees, paving the way for potential applications of stingless bee honey in clinical therapy.