Investigational study of Juglans regia extract and quercetin against photoaging

Walnut contains different polyphenolic compounds with antioxidant activities, and it has long been known for its diverse pharmacological activities. However, anti-aging and anti-inflammatory effects of these have not been investigated. The objective of this work was to investigate the ability of Juglans regia kernels to protect mice skin against ultraviolet (UV) radiations-induced damage in vivo. To study the effect of walnut on collagen, the skin of mice was treated with 5% w/w of ethanolic extract of walnut over 12 weeks. The physical parameters, like wrinkle assessment, biochemical parameters evaluation viz. collagen levels, TBARS, GSH, etc. and histological parameters’ evaluations were performed. Conversely, the extract was not able to revive morphological normality of skin, as compared to the standard group (quercetin treated). Histopathological studies confirmed increased protection of the skin by quercetin treatment, rather than crude extract. The extract may owe its protective effect by the extract due to the MMP-1 inhibition in addition to the suppression of MIP-α, thus, downregulating the inflammatory response.