Preparation Of And Anti-Cancer Activity Evaluation Of The Nanoparticles Ofβ-Lactoglobulin-Epigallocatechin Gallate

(-)-Epigallocatechin gallate (EGCG), as the most abundant catechin and major biologically active component in green tea, has been shown to possess potential activities in antioxidant, antimutagenic, antiobesity, antibacterial, antiviral, and protective effects from many diseases, such as cancer, cardiovascular disease, diabetes, and inflammation. However, the instability and low bioavailability of EGCG limit its commercial applications in food and medicine. Nanotechnology is an effective method to protect the core material from adverse environmental conditions, and offer major improvements in therapeutics through site specificity, their ability to escape from multi-drug resistance, and the efficient delivery of an agent. β-Lactoglobulin ((3-LG), a water-soluble protein that forms the major component of ruminant milk whey, has been used as a carrier molecule for resveratrol, curcumin, and ω-3polyunsaturated fatty acids to improve their stability and bioavailability.In this study, EGCG was loaded in heat treated β-lactoglobulin (β-LG) for the preservation of antioxidant activity and enhance of antitumor activicity. The effects of pH (2.5-7.0), the heating temperature of (3-LG (30-85℃), the molar ratio of (3-Lg to EGCG (1:2-1:32), and the β-LG concentration (1-10mg/mL) on the properties of (3-Lg-EGCG complexes were studied. All four factors significantly influenced the particle size, the zeta potential, and the entrapment efficiency of EGCG and EGCG loading inβ-LG particles. A stable and clear solution system and higher entrapment efficiency of EGCG could be obtained at pH6.4-7.0and the heating temperature of β-LG70-85℃. After analysis of the secondary structure of samples by fourier transform infrared (FTIR) spectroscopy, β-LG-EGCG nanoparticles were found to have the same secondary structure as native (3-LG. β-LG-EGCG nanoparticles and pure β-LG were white spheroid observed using transmission electron microscope. The slowest release of EGCG and highest protection of EGCG antioxidant activity was obtained with β-LG heated at85℃, the molar ratio of1:2(β-LG:EGCG) and neutral pH. Seven groups of β-LG-EGCG nanoparticles (LENP1, LENP2, LENP3, LENP4, LENP5, LENP6, LENP7) were prepared at different conditions, and their antitumor activity were evaluated in vitro and in vivo. The tumor inhibition rates of LENP3and LENP6in mouse hepatoma cell line H22cells and H22bearing mice were higher than that of free EGCG at the same dose. In addition, LENP6significantly increased the thymus index and spleen index of mice. These results were helpful to the utilization of β-LG as a protective vehicle for EGCG and other polyphenols in food, drinks and medicine.