Th e antioxidant capacity and immunomodulatory activity of stingless bee honeys proceeding from Costa Rica

Abstract

Luis Gabriel Zamora, Kees Beukelman, Bert van den Berg,Maria Laura Arias, Eduardo Umana, Ingrid Aguilar,Linda Quarles van Ufford1, Edwin van den Worm, Natalia Fallas,Rebeca Solorzano

Objective: Medihoney® is considered up to date the only antioxidant therapy specifically approved by the United States food and drug administration for wound healing. This is the first study that evaluates the antioxidant capacity and immunomodulatory activity of stingless bee honeys in comparison to Medihoney®. The goal of this study was to evaluate in-vitro the potentials of Meliponini honey from Costa Rica as an antioxidant wound dressing agent. Materials and Methods: A total of 57 honeys belonging to the Tetragonisca angustula (n = 36) and Melipona beecheii (n = 21) species were studied. Following tests were carried out: Screening of radical scavenging activity by the 2,2-diphenyl-1-picrylhydrazyl assay (DPPH), superoxide anion radical scavenging assay, inhibition of xanthine oxidase (XO), total phenolic (TP) content by the Folin–Ciocalteu reagent, and the oxygen radical absorbance capacity (ORAC) assay. Furthermore, the effect of honey over reactive oxygen species (ROS) produced by human polymorphonuclear leucocytes (PMNL) was evaluated using luminol and a Cypridina luciferin analog as luminescence probes. Results: The positive correlation between the TP content and the ORAC value reported herein, suggests that the antioxidant capacities of the stingless bee honeys examined are given in a major grade to their phenolic constituents. According to present results, the in-vitro immunomodulatory activities are explained mainly due to the radical scavenging effect and to the XO inhibition. Both mechanisms may play a role in the impairment of the inflammatory process and the promotion of redox homeostasis.Conclusion: The T. angustula honeys showed antioxidant capacities not statistically different to Medihoney®. In addition, their radical scavenging activity over ROS produced by human PMNLs and inhibition of XO justify their ethnopharmacological use as a wound dressing and further research toward novel wound-healing developments.