Enhanced electronic absorption and solubility of Mammeigin in aqueous micelles and protein aggregate solutions compared to water

Abstract

The physicochemical properties of plant polyphenol Mammeigin (MMG) from Mesua ferrea, upon interactions with carrier molecules like surfactants and Hen Egg-White Lysozyme (HEWL) aggregates were investigated using UV–Vis and Fluorescence spectroscopy; and Zeta potential (ZP) measurements in aqueous solutions. The role of surfactant charge on the interactions of MMG was studied using anionic Sodium Dodecyl Sulfate (SDS), cationic Cetyltrimethylammonium Bromide (CTAB), and neutral Tween 20 (T20). It was observed that ionic surfactants offered more stability to the system, which was enhanced in the presence of salt at physiological concentration and lower amounts of surfactant. The environment of MMG in these micelles was proposed to be partially semi-polar in nature based on solvent studies in organic and binary solvent systems. A similar favorable environment was found in early and partially exposed aggregates of HEWL at pH 2 and pH 9 respectively, which significantly diminished at later stages of aggregation and fibrillation at pH 2. With growing interest in plant polyphenols as bioactive, a major challenge for their utility in biological systems is the aqueous insolubility and thus, research in the field of drug/compound delivery is expanding. Our study could provide insights for developing better molecular carriers and formulations of MMG at physiological conditions for therapeutic applications with improved efficacy.