Anti-inflammatory and safety assessment of Polyscias fruticosa (L.) Harms (Araliaceae) leaf extract in ovalbumin-induced asthma

Abstract

Background: Polyscias fruticosa is a plant used in the traditional management of asthma in Ghana. Aim: This study evaluated the anti-inflammatory property of an ethanolic leaf extract of Polyscias fruticosa and safety for use in ovalbumin-induced asthma. Methodology: The total and differential white blood cell counts, C-reactive protein level, and erythrocyte sedimentation rate were determined for blood samples obtained from Duncan Hartley guinea-pigs following sensitization (150 µg OVA + 100 mg aluminium hydroxide, I.P), OVA aerosol challenge, and treatment with 2 ml/kg normal saline, 10mg/kg prednisolone and 100, 250 or 500 mg/kg of the extract. An acute and delayed toxicity study was also conducted. Results: White blood cells and its differentials were significantly elevated (P ≤ 0.05) after OVA-induced asthma. Treatments with the extracts and prednisolone significantly reduced (P≤0.05) elevated white blood cells and its differentials. Elevated serum C-reactive protein (≥ 6.0 ± 0.00 mg/l) was reduced to within normal levels, and there was a significant decrease (P ≤ 0.01) in erythrocyte sedimentation rates in PFE and prednisolone-treated animals following OVA-induced asthma. PFE showed no significant toxic effect at lower doses (NOAEL: < 1000 mg/kg) Conclusion: The ethanolic leaf extract of Polyscias fruticosa reduces white blood cell count and its differentials in blood, hence its anti-inflammatory effect; a useful property in the treatment of asthma.