New Epigallocatechin Gallate (EGCG) Nanocomplexes Co-Assembled with 3-Mercapto-1-Hexanol and beta-Lactoglobulin for Improvement of Antitumor Activity

(-)-Epigallocatechin-3-gallate (EGCG), as the major catechin in green tea, is a potent antioxidant with numerous reported health benefits such as anti-proliferative and pro-apoptotic effects. Nanovehicles for EGCG delivery can effectively improve its antioxidant capacity, absorbability and bioavailability in vivo. We used thermally modified beta-lactoglobulin (beta-Lg), 3-mercapto-1-hexanol (3MH) and EGCG to form stable co-assembled nanocomplexes (ME beta-NPs) with greater stability, sustained release and anticancer effects in vitro and in vivo than free EGCG. ME beta-NPs inhibited A375, Hep G2 and TE-1 tumor cell proliferation with 65.90%, 60.44% and 32.88% greater activity, respectively, than EGCG. ME beta-NPs with 100 mg EGCG/kg (3MH/EGCG/beta-LG = 4: 32: 1) were not toxic to mice and inhibited implanted human melanoma A375 cell tumor growth by 57.78%, twice as effective as EGCG alone. Thus, ME beta-NPs have greater stability and antitumor activity than EGCG, with potential value for anticancer therapy.