Nanoencapsulation of Polyphenols as Drugs and Supplements for Enhancing Therapeutic Profile - A Review.

Polyphenolic phytoconstituents have been widely in use worldwide for ages and are categorised as secondary metabolites of plants. The application of polyphenols such as quercetin, resveratrol, curcumin as nutritional supplements has been researched widely. The use of polyphenols and specifically quercetin, for improving memory and mental endurance has shown significant effects among rats. Even though similar results have not been resonated among humans, but preclinical results have encouraged researchers to explore other polyphenols to study the effects as supplements among athletes. The phytopharmacological research has elucidated the use of natural polyphenols to prevent and treat various physiological and metabolic disorders owing to their free radical scavenging properties, anti-inflammatory, anti-cancer, and immunomodulatory effects. In- -spite of the tremendous pharmacological profile, one of the most dominant problem regarding the use of polyphenolic compounds is their low bioavailability. Nanonization is considered as one of the most prominent approaches among many. This article aims to review and discuss the molecular mechanisms of recently developed nanocarrier-based drug delivery systems for polyphenols and their application as drugs and supplements. Nanoformulations of natural polyphenols as bioactive agents, such as quercetin, kaempferol, fisetin, rutin, hesperetin, and naringenin epigalloccatechin- 3-gallate, genistein, ellagic acid, gallic acid, chlorogenic acid, ferulic acid, curcuminoids, and stilbenes is expected to have better efficacy. These delivery systems are expected to provide higher penetrability of polyphenols at cellular levels and exhibit a controlled release of the drugs. It is widely accepted that natural polyphenols do demonstrate significant therapeutic effects. However, the hindrances in their absorption, specificity, and bioavailability can be overcome using nanotechnology.