Nano-encapsulation of a natural polyphenol, green tea catechins: Way to preserve its antioxidative potential

Abstract

Emanating from extensive research carried out all over the globe, green tea has been acknowledged for plethora of pharmacological activities like anti-inflammatory, antimicrobial, antitumor, antiaging, and many more. This wide array of health effects have been attributed to green tea catechins (GTCs). These GTCs correspond to the class of antioxidants which scavenge the precarious free radicals in the body and, thus, prevent the progression of various diseases. However, poor bioavailability, short halflife, stability issues, and short shelf life hamper its use as a therapeutic agent. To address these limitations, various encapsulation techniques have been explored by the scientists. The encapsulation techniques employed for green tea and its catechins range from microparticles, microcapsules, nanoparticles, and lipid nanocapsules to self assembly approaches like liposomes, micelles, and microemulsions. Encapsulation not only helps in enhancing the aqueous solubility and stability of the GTCs but also provides for controlled and sustained release thus protecting their biological/pharmacological activity in systemic circulation. At the same time, sustained release is likely to enhance bioavailability and thus can reduce the likelihood of repeated use. The aim of this chapter is to discuss the role of green tea as an antioxidant and various nano-encapsulation strategies to enhance the efficacy of related products. It also provides an insight into some of the commercial and patented green tea- based products.