Hylocereus polyrhizus peel extract restricts DMBA-Croton oil induced skin carcinogenesis: An integrated in vivo and in silico approach

Hylocereus polyrhizus, locally known as red dragon fruit, is valued for its nutritional benefits including high levels of antioxidants and is gaining popularity as both a food and a medicinal plant. The present study addressed the in vivo and in silico chemopreventive potential of Hylocereus polyrhizus peel extract (HPPE) in DMBA-croton oil induced skin carcinogenic model mice. The mRNA expression level of pro-inflammatory cytokines and inflammatory mediators in tumor mass were estimated by real time-RT-qPCR. In addition, molecular docking and molecular dynamic simulation analyses were conducted on the reported compounds. In the in vivo chemopreventive activity assessment, the peel extract at 500 mg/kg was found effective in reducing total tumor number, yield, burden, incidence, and weight. Total proteins and endogenous antioxidants (GSH, SOD, CAT) levels in liver and skin tissues from mice were significantly ( P<0.05 ) elevated. In addition, the HPPE at 500 mg/kg dose significantly reduced ( P<0.05 ) the gene expression of pro-inflammatory cytokines such as TNF- α , IL-1 β , IL-6, IL-18, and inflammatory mediators like TGF- β 1, COX-2, and NFκ Β . In the molecular docking studies, reported compounds including Quercimeritrin, Rutin, and Kaempferol 3-O-β-D-glucopyranoside were identified as the top-performing compounds, with a docking score of - 7.4, -7.1 and -7.0 kcal/mol against TGF- β 1 protein. This indicates stronger binding interactions compared to vincristine (-5.3 kcal/mol). In drug-likeness assessment, all compounds demonstrated the most favourable ADMET and pharmacokinetic profile. Furthermore, MDS data showed greater dynamic stability for Kaempferol 3-O-β-D-glucopyranoside and Rutin, while vincristine exhibited higher fluctuations. The results suggest that HPPE may serve as a potential inhibitor of skin carcinogenesis through upregulating endogenous antioxidants as well as suppressing different proinflammatory and inflammatory cytokines. Quercimeritrin, Rutin, and Kaempferol 3-O-β-D-glucopyranoside might be the probable leads responsible for this chemopreventive activity.