in vitro Cytoprotective Study of Litsea oppositifolia Bark Extract Against UVB Exposure

Abstract

Exposure of human skin to the sun has been known to have adverse effects. UV radiation, namely UVB (280-315 nm), is known to cause sunburn in the skin, as it induces cytokines, neuroactive, and vasoactive mediators that trigger an inflammatory response. Other than that, UV exposure is also linked with skin darkening, as it upregulates melanin accumulation in the epidermis. This increases the risk of melanoma in people. UV exposure also induces reactive oxygen species (ROS) in the skin. This study compares the Litsea oppositifolia bark extract as a potential solution that protects against UVB exposure, and its cytoprotective protective abilities were observed towards HaCaT cells. DPPH assay was performed, where it was observed that LO bark extract had an IC of 48.660 ppm ± 3.97, which is weaker than ascorbic acid with an IC 50 50 of 3.853 ppm ± 2.27. The optimum UVB time and distance deemed cytotoxic to the cells was 6 hours from 15 cm. The extract was not cytotoxic to the cells, but ascorbic acid is cytotoxic from a concentration of 50 ppm. The cytoprotective assay showed that LO bark extract exhibited cytoprotective abilities at 100 ppm when exposed to UVB light. However, AA still had stronger cytoprotective abilities at lower concentrations, namely 25 and 50 ppm. Therefore, it was confirmed that LO bark extract exhibited antioxidant activity and cytoprotective abilities, although weaker when compared to AA.