Methylglyoxal—A Potential Risk Factor of Manuka Honey in Healing of Diabetic Ulcers

Juraj Majtan

doi:10.1093/ecam/neq013

Abstract

Honey has been considered as a remedy in wound healing since ancient times. However, as yet, there are inadequate supportive robust randomized trials and experimental data to fully accept honey as an effective medical product in wound care. Manuka honey has been claimed to have therapeutic advantages over other honeys. Recently, it has been documented that the pronounced antibacterial activity of manuka honey is due, at least in part, to reactive methylglyoxal (MG). The concentration of MG in manuka honeys is up to 100-fold higher than in conventional honeys. MG is a potent protein-glycating agent and an important precursor of advanced glycation end products (AGEs). MG and AGEs play a role in the pathogenesis of impaired diabetic wound healing and can modify the structure and function of target molecules. This commentary describes the concern that MG in manuka honey may delay wound healing in diabetic patients. Further detailed research is needed to fully elucidate the participation of honey/derived MG in healing diabetic ulcers. We advocate randomized controlled trials to determine efficacy and safety of manuka honey in this population.

Highlights

The prevalence of diabetes is rapidly increasing worldwide
It has been suggested that concentrations of MG above 150 mg kg−1 are directly responsible for the characteristic antibacterial properties of manuka honey [44]
A number of randomized clinical trials suggest that medical grade honey promotes wound healing but most of them have not included diabetic patients with chronic leg ulcers and nearly three-quarters of clinical trials have focused on the use of honey for acute wounds, in particular burns

Summary

Introduction

The prevalence of diabetes is rapidly increasing worldwide. The occurrence of diabetic foot ulcers is a serious complication which negatively affects patients’ quality of life. Among persons diagnosed with diabetes mellitus, the prevalence of foot ulcers is 4%–10% [1]. Treatment of foot ulcers is protracted and intensive and associated with high costs. Various approaches have been developed for the treatment of diabetic ulcers including topical wound-care therapies. Current therapeutic products which are being used widely in wound care, such as silver sulfadiazine, hydrogel, hydrocolloid and alginate dressings impregnated with silver, are generally accepted as being useful for control of bacterial infections. Increased use of ionic silver in wound care has created some concern regarding the development of bacterial resistance [2, 3]. Modern medicine directs attention to natural products with antimicrobial activity and their use in clinical practice. Some of the natural therapies such as maggot debridement therapy and phage therapy have recently been reexamined for their potential usefulness in the treatment of wounds that are difficult to heal [7,8,9,10]

Honey as a Traditional Antimicrobial Agent

Clinical Evidence for the Use of Honey in the Management of Chronic Wounds

Methylglyoxal Concentrations in Honey

Biological Properties of MG and AGEs

The Roles of MG and AGEs in Impairment of Diabetic Wound Healing

Conclusion