Unripe Carica papaya protects skin keratinocytes against UVB-induced cell death via antioxidative and anti-inflammatory mechanisms

Abstract

Objective: To investigate the mechanisms by which unripe papaya extract (UCP) protects skin keratinocytes from UVB-induced inflammation and apoptosis.

Methods: High-performance liquid chromatography was used to identify the phytochemical composition of UCP. The free radical scavenging capacity of UCP was assessed against O2.-, and H2O2. HaCaT cells were pre-treated with varying concentrations of UCP and exposed to 40 mJ/cm2 UVB radiation. Cell viability, reactive oxygen species (ROS) levels, apoptotic markers, and inflammatory mediators were evaluated using standard biochemical assays and molecular techniques.

Results: UCP treatment significantly improved cell viability and reduced intracellular ROS and the release of O2.- and H2O2. UCP also inhibited apoptosis, as evidenced by reduced cytochrome c release and suppression of Akt phosphorylation. Additionally, UCP exhibited anti-inflammatory effects by downregulating COX-2 expression, suppressing PGE2 release, and inhibiting c-Jun and NF-κB signaling pathways.

Conclusions: UCP effectively protects skin keratinocytes from UVB-induced oxidative stress, inflammation, and apoptosis. These findings support its potential as a natural therapeutic agent for preventing UV-related skin damage. However, in vivo studies are warranted to confirm its efficacy.

Keywords

Carica papaya / Keratinocytes / Ultraviolet rays / Antioxidants / Inflammation

Conflict of interest statement

The authors declare that there is no conflict of interest.

Funding

This research was supported by the Faculty of Medicine, Srinakharinwirot University (Research Grant 129/2560). The UV irradiation system was supported by the Equipment Subsidies Program of the Alexander von Humboldt Foundation.

Data availability statement

The data supporting the findings of this study are available from the corresponding author upon request.

Authors’ contributions

SKW and WJ contributed to concept and design. WJ, KK, SKW, and LC were involved in methodology, analysis, and interpretation. WJ, KK, and TS performed data collection. WJ, KK, and SKW wrote the original article, and SKW did critical revision of the manuscript and confirmed final approval of the manuscript. WJ and SKW were responsible for statistical analyses. SKW obtained funding and had overall responsibility.

Publisher’s note

The Publisher of the Journal remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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