COMPARATIVE EFFECTS OF SOME ARGININE AND TYROSINE-DERIVED MAILLARD REACTION PRODUCTS ON KEY ENZYMES LINKED WITH ERECTILE DYSFUNCTION

Abstract

Maillard reaction products are commonly attributed to browning of foods and are known for their flavour enhancing properties, beyond this they act as modulators of several pathological conditions such as; male erectile dysfunction (ED). Hence this study sought to compare the effects of some Maillard reaction products (MRPs) synthesized from tyrosine and arginine on key enzymes linked to ED. The MRPs were synthesized by heating equimolar solutions of tyrosine and arginine with four different sugars (glucose, sucrose, fructose and maltose) in an oven for 1.5 hr at 110οC to yield the MRPs. Results revealed that all MRPs possess antioxidant potentials as they were able to scavenge DPPH, NO*, OH*, ABTS radicals, exhibited Fe2+ chelating, Ferric reducing antioxidant properties and inhibited lipid peroxidation in vitro. The MRPs also demonstrated arginase and phosphodiesterase-5 inhibitory properties (enzymes linked to ED). Furthermore, total melanoidin content ranged from 1.59 g/100g to 2.27 g/100g for the tyrosine-derived MRPs and ranged from 1.58 g/100g to 2.25 g/100g for the arginine derived MRPs. The ABTS, Fe2+ Chelation, Fe2+ Induced lipid peroxidation and arginase inhibitory activity agreed with the melanoidin content. Hence the antioxidant and enzyme inhibitory effect of the MRPs suggest a relationship with the melanoidin content and also suggest the modulatory role of MRPs in erectile dysfunction.