Beneficial effects of Gelsemium-based treatment against paclitaxel-induced painful symptoms

Chemotherapeutic drugs induce various side effects including painful peripheral neuropathy that represents a major concern. The widely used anticancer drug paclitaxel causes neurological side effects such as burning pain, allodynia, and hyperalgesia. Neuroprotective substances that may effectively counteract paclitaxel-induced neuropathic symptoms are needed. Here, we investigated the potential of Gelsemium sempervirens (GS) to counteract paclitaxel-evoked painful neuropathy in rats. Using the von Frey hair and acetone behavioral tests, we investigated the potential of GS centesimal (C) dilutions 3, 5, and 9C to prevent or to correct paclitaxel-induced cold allodynia and mechanical allodynia/hyperalgesia involved in neuropathic pain. We found that a prophylactic or corrective treatment with GS dilutions prevented or suppressed PAC-evoked cold allodynia and mechanical allodynia/hyperalgesia, by reversing to normal, decreased cold thermal and mechanical pain thresholds of PAC-treated rats. In particular, preventive or corrective treatments with GS dilution 3C counteracted PAC-evoked allodynic and hyperalgesic responses. Also, GS dilution 5C (in a lesser extent than 3C) significantly reduced PAC-induced mechanical allodynia/hyperalgesia while GS dilution 9C was ineffective. PAC-evoked neuropathic symptoms were efficiently reduced after 1 week treatment with GS dilutions 3 or 5C and the beneficial action increased after 2 weeks. GS dilutions, particularly 3C, also counteracted or prevented PAC-induced sciatic nerve axon alterations and decreased the density of intraepidermal nerve fibers. Altogether, these results obtained in the rat preclinical model suggest that GS dilution-based treatment may constitute an interesting option to explore for the long-term management of pain without undesirable effects.