Rutin: A review on extraction, identification and purification methods, biological activities and approaches to enhance its bioavailability

Rutin is a common dietary flavonoid which has received great attention in literature, due to their pharmacological properties, including antimicrobial, anti-inflammatory, anticancer, antidiabetic, inter alia. Over 860 products containing rutin are currently marketed in the US. The major disadvantage associated with rutin is its constrained bioavailability, mainly caused by its low aqueous solubility, poor stability and limited membrane permeability. The aim of this contribution is to give an overview of the current methods (conventional and innovative) for the extraction, identification and purification of rutin. Furthermore, recent findings regarding its pharmacological activities and the different approaches to increase rutin solubility in both aqueous and lipid phases will be discussed. Current trends on extraction process have been focused on the discovery and design of green and sustainable extraction techniques to optimize the recovery of rutin. Despite the bioactivity expressed in different in vitro systems, its biological effects in vivo are limited by the poor bioavailability of the flavonoid. The utilization of delivery systems for rutin or its enzymatic or chemical transformation towards highly soluble derivatives have the potential to improve rutin bioavailability, as well as its stability and/or specific biological properties. These novel rutin formulations may bring this promising flavonoid to the forefront of nutraceuticals for the prevention and/or treatment of various chronic human diseases.