Phytochemical and analgesic evaluation of methanol leaf extract of <i>Clerodendrum volubile</i> Linn

Abstract

The toxic effects of known analgesics in pains and stress management are major health concern globally. This study therefore investigated the phytochemical and analgesic property of commonly used medicinal plant in southwestern Nigeria for pain management. Clerodendrum volubile (CVL) was screened for phytochemical constituents following standard procedure. Forty two Wistar Albino Mice (WAM) of both sexes (35-40 g, n=6) were grouped into seven. Thirty minutes prior to intraperitoneal injection with 2 ml of 0.1% acetic acid, animals in groups I- III received plant extracts (1 mg/kg, 10 mg/kg, 100 mg/kg respectively), IV- VI were treated with paracetamol (acetaminophen), aspirin and indomethacin while VII received saline water. Thirty minutes observation period was adhered to. Time related analgesic effect was also investigated. The results showed that the extract contained alkaloids, tannins, saponins, phenols, anthraquinones, and flavonoids. Analgesic assay revealed methanol leaf extract of CVL demonstrated a dose dependent activity on the acetic acid-induced writhing. Writhing counts significantly reduced in mice administered with 1-100 mg/kg CVL (85.17±3.72, 57.17 ± 4.07 and 40.00 ± 2.08) compared to paracetamol, aspirin, indomethacin (76.50±7.64, 45.67± 2.73, 33.50 ± 4.23) and saline water (207.83±9.95). Percentage inhibition of abdominal constriction was dose dependent in methanol leaf extract of CVL (87.00±0.03%) relative to control (0.00%). These findings support the previously reported analgesic and anti-inflammatory activities of extracts of other species related to the study plant.

Keywords: Clerodendrum volubile, medicinal plants, musculoskeletal disorder, phytochemical. metals