The role of bioactive phytoconstituents-loaded nanoemulsions for skin improvement: a review

Abstract

As the largest organ in the human body, the skin should be protected from various harmful chemicals and pollutants from the surrounding environment and ultraviolet (UVA/UVB) radiation emitted from sunlight. This has prompted formulation scientists to embark on new technology to formulate cosmetics free of synthetic chemicals using natural plant-based extracts as the replacement. Natural phytoanti-oxidants, viz. catechin, quercetin and gallic acid, are polyphenols whose therapeutic values (antioxidative, antityrosinase, antiviral and antimicrobial) are underutilized. Plant-based nanoemulsions offer an efficient and safe topical delivery system for improving the skin and regenerative treatment. The bioavailability of the phytoanti-oxidants for molecular-level skin repair is enhanced by better permeation of the nanoemulsions’ nano-sized particles through the stratum corneum. This review highlights several phytoconstituent-containing nanoemulsions and their bioactivities for cosmetic applications. The mechanisms of skin improvement for anti-aging skin are also presented in detail. In short, nanoemulsion technology is a powerful tool for an effective topical delivery system of potent skin-protecting and rejuvenating plant-based extracts. With increasing demand from consumers worldwide for nano-formulated phytohormones or phytoextractives, nanoemulsions will see a new dimension with better future prospects.