The effect of a fatty acid-based carrier on the bioavailability of epigallocatechin gallate

Abstract

Background: Potential health benefits of green tea and green tea catechin, epigallocatechin gallate (EGCG), in humans include prevention of cancer, prevention of cardiovascular disease, prevention of diabetes mellitus, reduction of the risk of hypertension development, prevention of obesity, prevention of dental caries, lowering of the prevalence of cognitive impairment and reduction in oxidative stress. Various studies have established that EGCG has very low bioavailability and thus there is a need to establish ways of increasing this. It is hypothesised that a fatty acid-based carrier, Pheroid™ could enhance the bioavailability of EGCG. Aim: The aim the study is to investigate the effect of Pheroid™ on the bioavailability of EGCG in healthy volunteers. Study design: A randomised, double-blinded crossover design study with a 3-day run-in period and a 3-day washout period was conducted. Subjects were provided with a low flavonoid/catechin free diet. Twenty (20) subjects ingested a single dose of 400 mg EGCG or 400 mg EGCG entrapped in Pheroid™ on two separate occasions in random order, and unchanged EGCG was measured in the blood over 8 hours at different time points. Setting: Metabolic Clinic, North-West University, Potchefstroom Campus, North-West Province. Results: When a non-compartmental pharmacokinetic analysis data was tested for significance, the areas under the plasma concentration curves [AUC (0^80 min)] for the first period showed a statistically significant difference between EGCG incorporated in Pheroid™ (50744±26273 min*ng/ml) and EGCG (18106±13158 min*ng/ml) with a p value of 0.005. These results should however be treated with caution as only first period data was analysed, therefore, losing the advantages of a crossover design. Maximum concentration for EGCG plus Pheroid™ (224±271 ng/ml) was higher than that of EGCG alone (139±117 ng/ml) and Tmax of EGCG plus Pheroid™ (200±107 min) was shorter than the EGCG alone (236±65 min), suggesting that there was an increased bioavailability, however with no statistical significance. Similar results were obtained when data generated from a one-compartmental pharmacokinetic analysis model was analysed, confirming that Pheroid™ did not increase EGCG bioavailability significantly. Conclusion: A dosage of 400 mg EGCG is safe and well tolerated by healthy individuals. In this study, it was found that Pheroid™ did not increase bioavailability of EGCG significantly.