Lithium prevents the neurotoxic effects of paclitaxel mediated through TRPA1 channels

Paclitaxel (PTX) is a drug commonly used in cancer chemotherapy despite its neurotoxicity. TRPA1 channels are essential mediators of sensory transduction and nociception. These cation channels are linked to PTX-induced neurotoxicity, which Li⁺ prevents. This study aimed to examine the effects of Li+ on PTX-induced neurotoxicity and on TRPA1 channels. We utilized the SH-SY5Y cell line to assess cell viability via the MTT assay. Intracellular Ca²⁺ concentration in Fura-2-loaded cells was measured using spectrofluorometry. TRPA1 channel activity was evaluated with whole-cell patch-clamp recordings. The effects of PTX, Li⁺, and TRPA1 agonists and antagonists were tested. Motor function, thermal response, and cognitive performance were assessed in adult Wistar rats with neuropathy induced by PTX. PTX (100 nM) significantly reduced cell viability, and Li⁺ (10 mM) alleviated this effect. AITC (300 µM), a TRPA1-selective agonist, decreased cell viability, with a more pronounced impact when PTX was present. A967079 (10 µM), a selective TRPA1 antagonist, significantly lessened the cytotoxicity caused by PTX. Li⁺ reduced the cytotoxic effects of TRPA1 activation both with and without PTX. PTX increased TRPA1 currents and amplified TRPA1-mediated intracellular Ca²⁺ increase, while Li⁺ neutralized both effects. Additionally, PTX causes sensorimotor and cognitive neuropathy, which was reversed by Li⁺ treatment. These findings suggest that Li⁺ may act as a neuroprotective agent, preventing neuronal damage caused by PTX via TRPA1 channel pathways.