Pomegranate peel extract ameliorates UVA radiation induced skin damage in A375 cells

Abstract

UVA, the largest portion of solar radiation penetrates the deeper layers of skin and causes skin oxidative stress from free radicals' generation. Pomegranate (Punica granatum L) is a rich source of polyphenolics that has captured increased interest of its feasibly use for cosmetic application. The peel was extracted using 70% ethanol and phytochemicals content analyzed for total phenolics and flavonoids content. Antioxidant activities of the extract were also examined using DPPH assay, FRAP assay and metal chelating assay. Oxidative stress reduction by pomegranate peel extract (PPE) was evaluated on A375 cells under H2O2 and UVA treatment. Results revealed that PPE contained total phenolic content (TPC) at 149.4±7.44 mg Gallic acid equivalent /g dried extract and total flavonoid content (TFC) at 13.93±0.45 mg catechin equivalent / g dried extract. Antioxidant activity of the extract was at 102.11±20.02 mg Vit C eq/g by DPPH assay, 92.22±2.08 mg TE/g by FRAP assay and 5.2±1.8 mg EDTA eq/g by metal chelation power assay. The PPE decreased 50% cell viability at 282.86±8.64 μg/ml to human melanoma cell A375 cells. The safe dose of pomegranate peel extract at 20 μg/mL attenuated H2O2 to cell viability at 94.60±10.23% as compared to H2O2 stressed cells at 81.43±3.89%. The PPE also had UVA prevention by enhancing cell viability of UVA treated cells at 68.80±4.21% to 105.86±13.49%. Furthermore, PPE could protect UVA cell damage via post-treatment rather than pre-treatment by reviving stressed cells to high cell viability. The results suggest that pomegranate peel extract may be beneficial in the treatment of UVA-induced skin oxidative injury after sunbathing, and it could be used as ingredients in skincare lotion.