Cyto-genotoxic assessment of bisphenol P through expression of DNA damage/repair genes in MDBK cell line

Bisphenol P (BPP) is a recognized endocrine disruptor with detrimental effects on human health. This study aimed to evaluate BPP's cytotoxic and genotoxic effects on Madin-Darby bovine kidney (MDBK) cells by examining changes in gene expression, genotoxicity, and cell survival. Various assays were employed, including the MTT assay, comet assay, micronucleus assay, and real-time PCR for gene expression analysis. Among the series of concentrations (0.5 µM, 1 µM, 2 µM, 4 µM, 8 µM, 16 µM, 32 µM, 64 µM, 128 µM, and 256 µM), the treatment with 32 µM BPP (LC₅₀) resulted in 50% cell viability after 24 h via MTT assay. The comet assay revealed a significant increase in comet tail length in BPP-treated groups compared to controls, indicating DNA with the highest damage at the 3xLC_50/2 dose concentration of BPP. The frequency of micronuclei (MNi) was higher than binuclei. A significantly higher level of cytokinesis-block proliferation index (CBPI) was also observed at higher doses than in the negative control group. Gene expression analysis indicated increased levels of OGG1 and HPRT1 in BPP-treated cells compared to untreated controls, with a dose-dependent elevation in OGG1 expression involved in DNA damage response. This study concluded that BPP exhibits both cytotoxic and genotoxic effects on MDBK cells. Expression of DNA repair genes (OGG1, HPRT1) served as biomarkers for genotoxicity. Furthermore, it is recommended that additional studies on BPP's molecular toxicity and its cross-species effects should be explored further to combat its harmful effects.