Studies On The Preparation And Characteristics Of EGCG-Phospholipid Complex

Phospholipids are the main components of the cell membrane and aid in the absorption of drugs.Phospholipid complex/phytosome are known to improve the solubility, stability, site specificity and hence, systemic bioavailability of plant active ingredients. Being a natural polyphenol, the (-)-epigallocatechin-3-gallate (EGCG) has been reported to have properties like powerful antioxidant, anti-inflammatory, anti-mutagenic and anti-carcinogenic which protect the body from cardiovascular diseases. However, the poor lipid solubility and low membrane permeability limits the use of EGCG as a treatment of human ailments.For good bioavailability, EGCG must have a good balance between hydrophilicity (for dissolving in the gastrointestinal fluids) and lipophilicity (to cross lipidic biomembrans). In our present study, we prepared the EGCG-phospholipid complex and investigated their physicochemical properties and bioactivity.Our study includes the following contents:1. The EGCG-phospholipid complex was prepared and investigated for various physico-chemical parameters like UV spectra, IR spectroscopy, X-ray powder diffractometry, differential scanning calorimetry and apparent water/n-octanol partition coefficient study. The results showed that no new compound was produced as EGCG and phospholipids complex were combined by noncovalent bond and apparent water/n-octanol partition coefficient of EGCG-phospholiplid complex was effectively enhanced. Based on the results, it can be concluded that the phospholipid complex may be considered as a promising drug delivery system for the improvement of overall absorption and bioavaibility of the EGCG molecule.2. To study the stability of EGCG-phospholipid complex in the artificial simulation intestinal juice, EGCG-phospholipid complex content in simulation intestinal fluid was measured by HPLC at different times. Results showed that EGCG-phospholipid complex improves15%to20%of the stability of EGCG in the simulation intestinal fluid. The antioxidant activities of EGCG-phospholipid complex were evaluated by various methods in vitro, which showed strong DPPH radical scavenging, ferric ion reducing capacity, ABTS radical scavenging activity and reducing power, moderate reducing superoxide radical scavenging activity.3. Transportation of EGCG-phospholipid complex at Caco-2cell monolayer model. We assessed the permeability of the EGCG-phospholipid complexe using the Caco-2monolayer and compared it with free EGCG. Results showed that EGCG and its phospholipid complex have no cytotoxicity on Caco-2cells in concentration less than100μg/mL. The membrane transport of free EGCG is remarkable efflux effect in Caco-2cell monolayers. Comparing with free EGCG, Papp values of membrane transport capacity from the apical (AP) to basolateral (BL) of EGCG-phospholipid complex were significantly increased from0.29to0.78(P<0.05), but the rise in its efflux ratios was relatively slow from0.84to1.15(P>0.05). Efflux ratio (Papp (BLâ†'AP)/Papp (APâ†'BL)) decreased from3.00to1.47. Phospholipids embedded EGCG, which could obviously promote the absorption of EGCG on Caco-2cell monmlayer model.