Anti-inflammatory effect of Phyllanthus acidus fruit extract through the suppression of IL-6 and IL-8 in UVB-irradiated keratinocytes with its phytochemical composition

UVB radiation is a major contributor to persistent skin inflammation and photodamage, primarily through the generation of reactive oxygen species (ROS), which promote the release of inflammatory cytokines, including IL-6 and IL-8. These cytokines play important roles in keratinocyte signaling and inflammatory regulation, and may contribute to cancer progression under chronic inflammatory conditions. Therefore, this study investigated the cytoprotective and anti-inflammatory potential of star gooseberry ( Phyllanthus acidus ) fruit extract, particularly its ability to suppress IL-6 and IL-8 in UVB-irradiated in vitro human keratinocytes. The extract significantly improved cell viability and reduced intracellular ROS levels in UVB-irradiated keratinocytes, as assessed using resazurin, Calcein AM/7-AAD staining, and H 2 DCFH-DA assays. HPLC peaks were assigned to gallic acid, catechin, caffeic acid, rutin, and quercetin based on comparison of their retention times with reference standards. Additional phytochemical constituents were tentatively identified using untargeted LC-QTOF-MS/MS analysis. The extract also exhibited radical-scavenging activity in the DPPH and ABTS assays. Preincubation with the extract significantly reduced IL-6 and IL-8 expression and their secretion levels in UVB-irradiated keratinocytes, as measured by real-time PCR and ELISA analyses. Taken together, these findings provide in vitro evidence of cytoprotective and anti-inflammatory effects of the extract in UVB-irradiated HaCaT cells. Further studies are needed to identify the constituents contributing to these effects and assess the safety and suitability of the extract for topical applications.