Ameliorative Effects of Ethanolic Leaf Extract of Palisota hirsuta K. Schum (Commelinaceae) on Vincristine-Induced Neuropathic Pain in rats.

ABSTRACT

Vincristine-induced neuropathy is a major dose-limiting side effect of cancer chemotherapy and thus effective therapeutic strategy is required. The present study utilized a rodent model of neuropathy to determine whether an ethanolic leaf extract of Palisota hirsuta (PHE), a plant widely used in West African traditional medicine for pain management and CNS disorders, could attenuate vincristine-induced neuropathic pain. Neuropathic pain was induced by injecting rats intraperitoneallywith vincristine (0.1 mg kg-1 day-1 in two 5-day cycles with a two-day break). Randall-Selitto Paw Pressure, Hargreaves, cold water (4-5˚C) and Von Frey Filaments tests were performed. These tests were used to assess the degree of mechanical hyperalgesia, thermal hyperalgesia and cold and tactile allodynia respectively as an index of peripheral and central pain sensation.Oral administrations of PHE (30-300 mg kg-1) significantly and dose-dependently ameliorated vincristine-induced pain-related behaviors. It significantly reduced both mechanical and thermal hyperalgesia and completely reversed vincristine-induced tactile allodynia at 100 and 300 mg kg-1 after 24 h. It however showed little effect on cold allodynia. These effects were similar to that of the gabapentin-treated group. In conclusion, oral administration of an ethanolic leaf extract of Palisota hirsuta attenuates pain-related behavior in vincristine-induced neuropathic pain model.