Antinociceptive Effect of in Paclitaxel-Induced Neuropathic Pain in Mice.

Paclitaxel-induced neuropathic pain (PINP) is a serious adverse effect of chemotherapy. () is a new food source used as herbal medicine in east Asia. We examined the antinociceptive effects of extract on PINP and clarified the mechanism of action of transient receptor potential vanilloid 1 receptor (TRPV1) in the spinal cord. PINP was induced in male mice using multiple intraperitoneal injections of paclitaxel (total dose, 8 mg/kg). PINP was maintained from D10 to D21 when assessed for cold and mechanical allodynia. Oral administration of 300 and 500 mg/kg relieved cold and mechanical allodynia. In addition, TRPV1 in the paclitaxel group showed increased gene and protein expression, whereas the 300 and 500 mg/kg groups showed a significant decrease. Among various substances in , vicenin-2 was quantified by high-performance liquid chromatography, and its administration (10 mg/kg, i.p.) showed antinociceptive effects similar to those of 500 mg/kg. Administration of the TRPV1 antagonist capsazepine also showed antinociceptive effects similar to those of , and is thought to exhibit antinociceptive effects on PINP by modulating the spinal TRPV1.