Evaluation of the inhibitory activities of acetylcholinesterase, α-glucosidase, pancreatic lipase and tyrosinase by phenolic extracts of honey

Enzyme inhibition is one of the targeted therapeutic strategies in the treatment of Alzheimer's disease, diabetes, obesity and hyperpigmentation. The objective of this work is to evaluate the inhibitory effect of phenolic extracts of honey on key enzymes that are involved in these diseases (acetylcholinesterase, α-glucosidase, pancreatic lipase and tyrosinase). The color of the honey samples was determined spectrophotometrically and the polyphenols of monofloral and polyfloral honeys were recovered by liquid-solid extraction using amberlite XAD-4 resin. The inhibitory activities of phenolic extracts on the four enzymes were tested with six concentrations and the results are expressed as IC50. The results obtained showed that the color of the tested honeys varied from extra light to dark amber. All the phenolic extracts tested exerted enzymatic inhibition. The phenolic fractions of Myrtaceae and polyfloral honeys showed the best anti-acetylcholinesterase, anti-α-glucosidase, anti-lipase and anti-tyrosinase activities, respectively. The inhibitory effect of these honeys was comparable to that obtained with the reference inhibitors (galanthamine, acarbose, orlistat and α-kojic acid). The correlation matrix revealed highly significant correlations between color and inhibitory activity of the honeys. Since acetylcholinesterase, α-glucosidase, pancreatic lipase, and tyrosinase are closely associated with Alzheimer's, hyperglycemia, obesity, and hyperpigmentation, the use of honey polyphenols may have a beneficial effect in treating these diseases.