Montmorillonite intercalated with glutathione for antioxidant delivery: Synthesis, characterization, and bioavailability evaluation

Abstract

A most powerful antioxidant, glutathione (GSH), plays an important role in detoxification, immune response, and protection against reactive oxygen species. However, orally ingested GSH can be easily degradable to free amino acids by chemical and enzymatic hydrolysis, resulting in low bioavailability. The aim of this study was, therefore, to enhance GSH bioavailability by developing GSH-montmorillonite (MMT) hybrid system. It was also coated with polyvinylacetal diethylaminoacetate (AEA) for better stability. Both GSH-MMT and AEA-GSH-MMT hybrids were characterized by powder X-ray diffraction (PXRD), Fourier transformed infrared (FT-IR), and thermogravimetric analysis (TGA), indicating that GSH was successfully intercalated into the interlayer spaces of MMT. In vivo antioxidant activity assay revealed that AEA-GSH-MMT hybrid significantly increased antioxidant activity in the plasma after oral administration in mice. Pharmacokinetic study also indicated that AEA-GSH-MMT hybrid considerably increased the plasma concentration of GSH at 1 h post-oral administration. Moreover, both the hybrid systems remarkably enhanced GSH delivery to the main target tissue, liver. All the results suggest that GSH-MMT hybrid systems have great potential to enhance bioavailability of oral GSH, providing new insight into their pharmaceutical application. © 2012 Elsevier B.V. All rights reserved.