Quantification of Antinociceptive and Anti-inflammatory Potentials of Different Ocimum gratissimum Linn. Leaf Extracts in Male Whistar Albino Rats
J. S. Aprioku *
Department of Experimental Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of Port Harcourt, P.M.B. 5323, East-West Road, Choba, Rivers State, Nigeria
O. S. Joseph
Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Uyo, Uyo, Nigeria
A. W. Obianime
Department of Pharmacology, Faculty of Basic Medical Sciences, University of Port Harcourt, P.M.B. 5323, East-West Road, Choba, Rivers State, Nigeria
*Author to whom correspondence should be addressed.
Abstract
Aim: This study was aimed at quantifying the antinociceptive and anti-inflammatory potency and efficacy of aqueous (AQ) and ethanolic leaf extracts of O. gratissimum (ET) in Whistar rats.
Methodology: Inflammation (paw edema) was induced in rats (n=5 per group) with fresh egg albumin (0.1 ml); groups for anti-inflammatory experiment were pretreated (0.5 h), while those for anti-nociceptive experiment were post-treated (2.5 h) with AQ (200, 400 or 800 mg/kg, p.o.), ET (200, 400 or 800 mg/kg, p.o.), piroxicam (20 mg/kg, i.p.), or normal saline (1 mL/kg, i.p.). Paw sizes of anti-inflammatory group rats were measured at 0 and 2 h after injection of phlogistic agent using plethysmometer, whereas mechanical nociceptive thresholds were measured in anti-nociceptive group rats before and 2 h after test agent treatments using analgesymeter.
Results: There was neither change in inflammatory reaction (after egg albumin injection at time 0 or 2 h) nor threshold in control rats before or after normal saline treatment. AQ inhibited (P = .05) paw edema at 400 mg/kg (26%) and 800 mg/kg (64%); whereas all three doses of ET caused inhibitions (35, 39 and 32%, respectively) compared to the egg albumin induced values. AQ and ET treatments increased (P = .05) mechanical nociceptive thresholds, but maximum effects were observed at 400 mg/kg for both extracts (144 and 270%, respectively) compared to values obtained before extract treatment. Piroxicam produced significant inhibitions in inflammation (20%) and nociception (100%).
Conclusion: ET is more potent, but AQ is about twice as efficacious as ET in anti-inflammatory activity. Also, ET is more potent and has a higher analgesic efficacy than AQ.
Keywords: Anti-inflammatory, antinociceptive, efficacy, O. gratissimum extract, potency