Bioavailability and bioactivity study of Epigallocatechin Gallate (EGCG) after in vitro digestion and in experimental mice model

Introduction: Recent years the scientific community search methods for Epigallocatechin Gallate (EGCG) bioavailability increase, with purpose to increase its bioactivity. Aim: The investigation of the hypothesis that EGCG incorporation into nanoemulsions may increase its bioavailability and bioactivity. Materials and methods: EGCG nanoemulsions into mayonnaise were evaluated after in vitro digestion procedure and were compared with aqueous EGCG solutions. In parallel, 40 C57/BL6 mice, were randomly assigned to receive by gavage 0,1 ml of the following: A: Distilled water, B: EGCG nanoemulsion (o/w)-0,23mg/ml, C: Aqueous EGCG 0,23mg/ml, D: Aqueous EGCG 0,23 mg/ml 80% and olive oil 20%, E: o/w control nanoemulsion, F: o/w nanoemulsion with esterified EGCG, G: w/o/w (8:32:60) control nanoemulsion H: w/o/w (8:32:60) nanoemulsion with 0,23 mg/ml aqueous EGCG. 2 h after receiving euthanasia was carried out and blood and selected tissues were collected and were evaluated for Total Antioxidant Capacity (TAC) with FRAP and ORAC methods and for EGCG detection with HPLC method. Results: The in vitro digestion retentates from EGCG nanoemulsions exerted increased TAC in comparison with aqueous EGCG solutions. “Real” mayonnaise with the simple EGCG had increased TAC compared with the esterified EGCG. Mice received all EGCG nanoemulsions exerted increased TAC in comparison with control groups in plasma and some tissues (heart, spleen, colon, jejunum), with greater activity of esterified EGCG. HPLC showed similar EGCG concentrations into plasma of mice received EGCG treatments, in aqueous or nanoemulsion form. Conclusion: Nanoemulsions use may lead to increase of EGCG bioavailability and thus its bioactivity.Figure 2Total Antioxidant Capacity (ORAC method) into mice plasma 2 h after receiving of nanoemulsions or aqueous solutions.View Large Image Figure ViewerDownload (PPT)