Phytochemical based nanomedicines against cancer: current status and future prospects

Cancer continues to be one in all the leading reasons for death worldwide. The mean cancer survival through standard therapeutic strategies has not been significantly improved over the past few decades. Hence, alternate remedies are needed to treat this terrible disease. Recently, natural compounds present in the plants, i.e. phytochemicals have been widely exploited for their anticancer potential. Phytochemicals may exhibit their anticancer activity through targeting different cancer cell signalling pathways, promoting cell cycle arrest and apoptosis, regulating antioxidant status and detoxification. Despite their excellent anticancer activity, the phytochemicals are limited by their low aqueous solubility, poor bioavailability, and poor penetration into cells, hepatic disposition, narrow therapeutic index and rapid uptake by normal tissues. Therefore, to address these challenges, the scientific community has shifted its significant interests towards nanocarriers-based delivery of phytochemicals due to their ability to enhance aqueous solubility, and bioavailability, specific tumour cell/tissue targeting, improved cellular uptake, reducing doses of phytochemicals and achieving steady-state therapeutic levels of the phytochemicals over an extended period of time. Additional advantages include excellent blood stability, multifunctional design of nanocarriers and improvement in anticancer activities. This review aims to summarise recent progress in phytochemical based nanomedicines for effective treatment of cancer.