Melatonin hyalurosomes as a powerful antioxidant for combating skin damage induced by UV radiation

Extrinsic skin aging is caused by chronic skin photodamage. The present study aims to inspect the role of nanoencapsulation of melatonin (MEL) in hyalurosomes in combating UVB-induced skin damage to take advantage of the hydrating penetration enhancing and antiaging effects of hyaluronic acid along with the powerful antioxidant effects of MEL. Measurement of particle size, zeta potential, encapsulation efficiency and <i>in vitro</i> MEL release were carried out. The <i>in vivo</i> photoprotective effects of MEL were tested in rats. A histopathological examination was conducted, and antioxidant and anti-inflammatory markers were measured along with estimating the expression of P38 MAPK, P-ERK and P-JNK. Particle size and zeta potential of MEL hyalurosomes were 285.9 nm and -26.3 mV with 95% entrapment efficiency and provided a sustained release profile for 48h. <i>In vivo,</i> results revealed the superior effect of MEL hyalurosomes in protecting skin against UVB-induced damage and reducing the levels of inflammatory mediators like TNF-α and IL6 compared with MEL suspension. However, they had a prominent role in increasing the levels of antioxidants. These findings may be accredited to the effect of nanoencapsulation in enhancing skin penetration and deposition of MEL besides the effect of hyaluronic acid as a powerful antiaging tool.