Attenuation of p38 MAPK/NF-κB/TRPV1/CGRP is involved in the antinociceptive effect of hesperidin methyl chalcone and taxifolin in paclitaxel-induced peripheral neuropathy.

Paclitaxel (PTX)-induced peripheral neuropathy (PIPN) is a disabling side effect of PTX, which adversely affects the life quality of cancer patients. Flavonoids such as hesperidin methyl chalcone (HMC) and taxifolin (TAX) can alleviate neuropathic pain via their anti-inflammatory, antioxidant, neuroprotective, and antinociceptive properties. The current study aimed to assess the efficacy of HMC and TAX in preventing PIPN individually or in combination. Pretreatment with HMC and TAX mitigated PTX-induced mechanical allodynia and hyperalgesia, cold allodynia, and thermal hyperalgesia as well as restore the normal histological architecture. Remarkably, neuropathic pain was relieved by suppression of nerve growth factor (NGF), p38 mitogen-activated protein kinase (p38 MAPK), and transient receptor potential vanilloid type-1 (TRPV1), which ultimately lead to reduced calcitonin gene-related peptide (CGRP). Furthermore, both HMC or TAX enhanced nuclear factor erythroid 2-related factor 2 (Nrf2), leading to elevated glutathione (GSH) and total antioxidant capacity (TAC) along with lowered malondialdehyde (MDA), which in turn, downregulated nuclear factor kappa B P65 (NF-κB P65) and its phosphorylated form and eventually reduced tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) then lowered the apoptotic indices. Promisingly, the combination of both agents was superior to each drug alone through targeting more diverse signaling pathways and achieving synergistic and comprehensive therapeutic effects. In conclusion, pretreatment with HMC and TAX separately or in combination alleviated PIPN via modulating NGF/p38 MAPK/NF-κB P65/TRPV1/CGRP pathway.