Suppression of TRPV1/TRPM8/P2Y Nociceptors by Withametelin via Downregulating MAPK Signaling in Mouse Model of Vincristine-Induced Neuropathic Pain

Abstract

Vincristine (VCR) is a widely used chemotherapy drug that induced peripheral painful neuropathy. Yet, it still lacks an ideal therapeutic strategy. The transient receptor potential (TRP) channels, purinergic receptor (P2Y), and mitogen-activated protein kinase (MAPK) signaling play a crucial role in the pathogenesis of neuropathic pain. Withametelin (WMT), a potential Phytosteroid isolated from datura innoxa, exhibits remarkable neuroprotective properties. The present investigation was designed to explore the effect of withametelin on VCR-induced neuropathic pain and its underlying molecular mechanism. Initially, the neuroprotective potential of WMT was confirmed against hydrogen peroxide (H2O2)-induced PC12 cells. To develop potential candidates for neuropathic pain treatment, a VCR-induced neuropathic pain model was established. Vincristine (75 μg/kg) was administered intraperitoneally (i.p.) for 10 consecutive days (day 1–10) for the induction of neuropathic pain. Gabapentin (GBP) (60 mg/kg, i.p.) and withametelin (0.1 and 1 mg/kg i.p.) treatments were given after the completion of VCR injection on the 11th day up to 21 days. The results revealed that WMT significantly reduced VCR-induced pain hypersensitivity, including mechanical allodynia, cold allodynia, and thermal hyperalgesia. It reversed the VCR-induced histopathological changes in the brain, spinal cord, and sciatic nerve. It inhibited VCR-induced changes in the biochemical composition of the myelin sheath of the sciatic nerve. It markedly downregulated the expression levels of TRPV1 (transient receptor potential vanilloid 1); TRPM8 (Transient receptor potential melastatin 8); and P2Y nociceptors and MAPKs signaling, including ERK (Extracellular Signal-Regulated Kinase), JNK (c-Jun N-terminal kinase), and p-38 in the spinal cord. It suppressed apoptosis by regulating Bax (Bcl2-associated X-protein), Bcl-2 (B-cell-lymphoma-2), and Caspase-3 expression. It considerably attenuated inflammatory cytokines, oxidative stress, and genotoxicity. This study suggests that WMT treatment suppressed vincristine-induced neuropathic pain by targeting the TRPV1/TRPM8/P2Y nociceptors and MAPK signaling.

Anti-Inflammatory and Anti-Rheumatic Potential of Selective Plant Compounds by Targeting TLR-4/AP-1 Signaling: A Comprehensive Molecular Docking and Simulation Approaches

“…These mediators further facilitate the infiltration of the immune cells and inflammatory mediators, which is associated with the tissue damage and discomfort. Several efforts are underway to explore new avenues for the treatment of inflammation and associated symptoms [56]. Plants are a rich and cheap source of drug development, and numerous plant-derived products are in clinical practice for the ailment of various diseases [57].…”

“…Computational drug design has recently been of focus for new drug development. In recent times, its use for the discovery of new drug development and the screening of large libraries of compounds in a very short time has tremendously increased [56].…”

Toxicity evaluation induced by single and 28-days repeated exposure of withametelin and daturaolone in Sprague Dawley rats

“…Abnormal gait in last week was also seen with piloerection in rats given withametelin (5 and 2.5 mg/kg). Studies on withametelin has been associated with brain in our previous work ameliorating oxidative stress in brain and spinal cord ( Khan et al, 2021b ; 2021a ). High doses of isolated compounds can be toxic due to their potential to react causing prooxidative effects or damaging beneficial ROS concentrations that normally exist under physiological conditions and are necessary for optimal cell function ( Bouayed and Bohn, 2010 ).…”

“…Its antileukemia effects are attributed to the inhibition of the spread of acute myeloid leukemia by targeting the signalling pathways of oncogenic kinase, which regulate the progression and survival of the cell cycle, thus resulting in an induction of apoptosis ( Akhtar et al, 2020 ). It relieves vincristine-induced neuropathic pain by analyzing results from behavior, biochemistry, histopathology and computational data, the molecular mechanism being associated with the suppression of TRPV1/TRPM8/P2Y nociception and MAPK signalling in mice ( Khan et al, 2021b ). It also shows neuroprotective properties by modulating the oxidative stress by Nrf2/Keap1/HO-1 in the CNS and the neuroinflammatory stress by TLR4/IκB-α/NF-κB/AP-1 in the CNS ( Khan et al, 2021a ).…”

Deletion of Tac1 gene impact kinase phosphorylation involved in signaling pathways associated with pain

“…Thus, we wanted to verify whether Tac1 -/- mice show defective pain modulatory pathways by specifically profiling protein kinases. Several kinases are implicated in peripheral and central sensitization, and their inhibition results in the attenuation of inflammatory and neuropathic pain (Khan et al, 2021; Ma and Quirion, 2005; Ruan et al, 2018).…”