ISSN 2326-7267
International Journal of Pharmacy and Pharmacology ISSN: 2326-7267 Vol. 9 (1), pp. 001-005, January, 2020. © International Scholars Journals
Full Length Research Paper
Antinociceptive and anti- inflammatory effects of the methanol seed extract of Carica papaya in mice and rats
A. O. Anaga* and E. V. Onehi
Department of Veterinary Physiology and Pharmacology, University of Nigeria, Nsukka, Enugu State, Nigeria.
Accepted 11 September, 2019
Abstract
The methanol seed extract of Carica papaya (CPE) was investigated for antinociceptive and anti-inflammatory activities in mice and rats. The brine shrimp lethality test of the extract showed LC50 of 106.94 ppm at 95% confidence interval. The extract (5, 10 and 20 mg/kg, p.o.) significantly (p < 0.05) increased pentobarbitone-induced sleeping time by more than 280% compared with the control. Like pethidine (9.1 mg/kg, i.p.), CPE (10 and 20 mg/kg, p.o.) significantly (p < 0.05) decreased the paw licking time in early (0 - 5 min) and late (25 - 30 min) phases of formalin-induced nociception. This antinociceptive effect was more in the late phase than early phase. Also, CP (5, 10 and 20 mg/kg, p.o.) significantly (p < 0.05) decreased the number of acetic acid-induced abdominal contortions by 25, 60, and 64%, respectively. Indomethacin (10 mg/kg, p.o.), CPE (5, 10 and 20 mg/kg, p.o.) showed a typical biphasic anti- inflammatory effect in carrageenin-induced paw oedema in rats. The anti-inflammatory effect though moderate, was dose-dependent and higher in 2 h than 4 h after administration of the phlogistic agent. In conclusion, CPE contains potent bioactive compounds (alkaloids, flavonoids and polyphenols) which showed antinociceptive effect probably mediated centrally and peripherally; and also involving mild anti-inflammatory mechanisms.
Key words: Carica papaya, brine shrimps, antinociception, anti-inflammatory.