On the role of epigallocatechin-3-gallate in protecting phospholipid molecules against UV irradiation.

Catechin molecules such as epigallocatechin-3-gallate (EGCG) are capable of attenuating the biomolecular damage induced by UV radiation, possibly through molecular mechanisms involving the cell membranes. In this study, we confirmed the protective role of EGCG against UV of 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol) (sodium salt) (DPPG) in liposomes and cast films. The incorporation of EGCG increased the stability of DPPG liposomes as indicated by UV-vis absorption spectra. Using 2D correlation spectroscopy to analyse the spectra, we found that DPPG and EGCG are co-helpers and complement each other against degradation induced by UV. At the molecular level, UV irradiation affects the phosphate and carbonyl groups of DPPG, in addition to triggering the oxidation and opening of the pyrogallol ring of EGCG. Since EGCG can be incorporated into liposomes and is a strong shield against UV radiation, one may envisage its use in anti-ageing and sunscreen creams, and in dermal drug delivery.