Abstract

E.A. Mangle and A. G Nikalje

The effect of Palisota hirsuta root ethanolic extract, a herbal preparation used in Ghana for pain and inflammatory disorders, was assessed in acute inflammation in carrageenan-induced foot oedema in chicks and brewer’s yeast-induced pyrexia in rats. Two paradigms were used for the inflammation assessment; effect of the extract on established inflammation (curative protocol) and effect before the induction of inflammation (preemptive protocol). P. hirsuta extract (50 - 400 mg/kg, p.o) dosedependently reduced foot oedema with maximal effect of 58.90 ± 11.38% (prophylactic) and 62.52 ± 4.73% (curative). Similarly, the NSAID, diclofenac (10 - 100 mg/kg, i.p.) used as a reference drug, dosedependently reduced the oedema with a maximal effect of 96.82 ± 3.64% (prophylactic) and 60.74 ± 5.58% (curative). The steroidal anti-inflammatory drug, dexamethasone (0.5 - 2 mg/kg, i.p), inhibited the oedema with a maximal effect of 86.51 ± 2.61% (prophylactic) and 55.76 ± 9.56% (curative). In terms of potency, the ethanolic extract of P. hirsuta exhibited similar potency when it was administered 1 h before (ED50 178.00 ± 56.8 mg/ kg) and 1 h after (ED50 181.10 ± 49.89 mg/kg) carrageenan injection and this was found to be less potent than both dexamethasone and diclofenac in both the prophylactic and curative protocols. Also, PHE caused a significant dose-dependent decrease in yeast-induced pyrexia in rats (IC50: 265.10 ± 63.73 mg/kg) which was ï?» 15 times less potent than the standard, paracetamol (IC50: 18.05 ± 4.08 mg/kg). The results thus confirm the use of the plant for inflammatory disorders in traditional medicine.