Petunidin attenuates vinclozolin instigated testicular toxicity in albino rats via regulating TLR4/MyD88/TRAF6 and Nrf-2/Keap-1 pathway: A pharmacodynamic and molecular simulation approach.

Vinclozolin (VZN) is a widely used fungicide which exerts deleterious impacts on various organs including testis. Petunidin (PDN) is a polyphenolic compound that demonstrates a broad range of pharmacological activities. Thirty-two rats were divided into 4 groups including the control, VZN (100 mg/kg), VZN (100 mg/kg) + PDN (4 mg/kg) and PDN (4 mg/kg) treated group. The activities of antioxidant enzymes were assessed by using previously documented protocols. The gene expressions were determined by using qRT-PCR. The levels of hepatic function and apoptotic markers were evaluated by using standard ELISA technique. The histological analysis was carried out as per the standard protocol of histology. It was revealed that VZN disrupted the Nrf-2/Keap-1 pathway. Moreover, the activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), heme-oxygenase-1 (HO-1) and glutathione reductase (GSR) were reduced whereas levels of reactive oxygen species (ROS) & malondialdehyde (MDA) were promoted following the VZN intoxication. Furthermore, VZN intoxication reduced total sperm count, viability, motility as well as luteinizing hormone (LH), follicle stimulating hormone (FSH), and plasma testosterone. Besides, administration of VZN decreased the expressions of 3β-Hydroxysteroid dehydrogenase (3β-HSD), steroidogenic acute regulatory protein (StAR) and 17β-Hydroxysteroid dehydrogenase (17β-HSD). Moreover, VZN exposure escalated the expressions of Bcl-2-associated X protein (Bax) and cysteine-aspartic acid protease-3 (Caspase-3) while reducing the expressions of B-cell lymphoma-2 (Bcl-2). Additionally, VZN administration increased the gene expression of toll-like receptor 4 (TLR4), tumor necrosis factor receptor-associated factor 6 (TRAF-6) and myeloid differentiation primary response 88 (MyD88). The levels of interleukin-6 (IL-6), nuclear factor kappa-B (NF-κB), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and the activity of cyclooxygenase-2 (COX-2) were promoted following the VZN administration. Furthermore, VZN intoxication disrupted the normal histology of testicular tissues. However, VZN + PDN treatment ameliorated testicular damage via regulating aforementioned dysregulations owing to its anti-inflammatory, antioxidative as well as anti-apoptotic potentials. Lastly, molecular docking (MD) was performed to assess the effectiveness of PDN as a curative compound by analyzing its binding affinity with the targeted proteins (Keap1, TLR4 and StAR). Our in-silico evaluations confirmed that PDN possesses the potential to interact with binding pockets of these proteins, emphasizing its capability as a curative compound to mitigate VZN-prompted reproductive damage.