Targeting JAK/STAT signaling pathway and anti-inflammatory markers using bakuchiol isolated from Psoralea corylifolia for cytotoxicity of human squamous cell carcinoma (A431) cells

Abstract

Objectives: Non melanoma skin cancers are common neoplasms worldwide. In India, squamous cell carcinoma (SCC), is the most prevalent skin disorder and its incidence rises quickly with cumulative exposure to sun. Numerous techniques are available for SCC but reversion and metastasis are common concern that needs effective and safe strategies for its control. With this in view, the study was planned to investigate the activity of Bakuchiol (Bak), traditionally used in various countries for curing skin ailments but its mechanism of action is unexplored. In our study, we explored anti-proliferative, pro-apoptotic and anti-inflammatory potential of Bak toward human squamous carcinoma (A431) cell line. Methods: The pure compound Bak was isolated from the plant Psoralea corylifolia and characterized using NMR, HRMS and FTIR. To explore their bioefficacy, different in vitro assays were performed against A431 cell line. To have molecular insights, RT-qPCR investigation was done to analyzed the expression level of inflammatory markers (TLR 9, IFN β, IL 23, JAK 3 and STAT 3). Results: The results showed the growth inhibitory effect on A431 cells after Bak treatment in dose-dependent way. To understand mode of cell death, cells were initially analyzed under phase-contrast, fluorescence and scanning electron microscope that showed characteristics of apoptosis. Furthermore, cell cycle studies with a flow cytometer were carried out which showed increased level of ROS, reduced MMP and cells arrested at G0/G1 phase in Bak treated cells further strengthening the induction of apoptosis. Moreover, RT-qPCR analysis indicated the downregulation of inflammatory markers in Bak-treated A431 cells that further confirmed its therapeutic role. The molecular docking study also confirmed that Bak has perfect scaffold that can complete the pharmacophoric need for JAK3 kinase inhibition. Conclusion: A critical analysis of results points towards the role of Bak in ameliorating inflammatory markers along with apoptosis induction in A431 cells by regulating the expression level of variable markers.

Keywords

• Antiproliferative activity
• Apoptosis induction
• Psoralea corylifolia
• Squamous
• Reactive oxygen species