Evaluation of the possible mechanisms involved in the anti-inflammatory and anti-nociceptive properties of Jobelyn® in laboratory rodents

Abstract

Background: Jobelyn (JB)® is a product derived from Sorghum bicolor. For several centuries, the people of Southwestern part of Nigeria have used this plant in its raw form to treat and cure many diseases. Previous studies have suggested JB efficacy in the treatment of pain, hence, the need for the exploration of its probable mechanism of its action. This study was undertaken to evaluate the mechanism of action through which JB exerts its anti-nociceptive and anti-inflammatory activities in rodents. Materials and methods: The administration of naloxone, prazosin and atropine (1 mg/kg, intraperitoneally) to groups of mice using acetic acid-induced abdominal writhing and formalin-induced paw licking tests were done to investigate the anti-nociceptive mechanism of action of JB. Animals were divided into six groups comprising of six mice in each experiment; two groups were orally administered normal saline (1ml/200g b.w) and indomethacin (2 mg/kg) respectively, while the remaining four groups were pre-treated intraperitoneally with the blockers followed by administration of JB (100 mg/kg). Hematoxylin and Eosin (H&E) staining and immunohistochemical analysis of rat paw tissues in carrageenan-induced hind paw edema in rats was used to analyze the level of inflammation. Results: Atropine significantly reversed the anti-nociceptive effects of Jobelyn® (100mg/kg) when compared with Jobelyn® in acetic acid-induced abdominal writhing test. In the formalin-induced paw licking test, the pre-treatment with the blockers showed no significance when compared with Jobelyn® group. Jobelyn (10, 50, 100, and 200mg/ kg) given orally, produced a significant inhibition of acute inflammation induced by carrageenan in rat paws, from which 100 mg/kg JB shows higher activity. The results from H&E staining and immune-histochemical analysis showed that JB considerably reduced the infiltration of inflammatory cells in the paw tissues.