Main Article Content
Anti-nociceptive and Anti-inflammatory Effects of Gmelina arborea Roxb. e x. Sm.
Abstract
Background: The aim of the present study was to evaluate the anti-inflammatory and anti-nociceptive activities of the methanolic extract of Gmelina arborea fruit (GAF) and stem bark (GASB) on egg-albumin induced inflammation and heated plate metal respectively.
Methods: 500 g of each of the pulverised samples was extracted with 90% methanol using soxhlet extractor to produce dense mass of methanolic extracts after distillation and kept in a refrigerator at 4oC until further analysis. The anti-inflammatory activity was determined on fresh egg albumins over 4 h by measurement of rat paw oedema according to established procedure. The anti-nociceptive was evaluated by placing each rat on the heated metal plate (Hot plate) maintained at the temperature of about 50-550C within the restraining plastic cylinder while animals responses were taken over 90 min.
Results: Methanolic extracts of G. arborea yielded blackish thick mass and greenish paste viscous extract for the GASB and GAF respectively with percentage yields of 28% and 30% respectively. The yield revealed more extractives in the GAF than GASB. The anti-nociceptive properties of both GAF and GASB shows a relatively time dependent activity as rate of inhibition was high at the 30th min (at the peak of p<0.001) for all doses except for 100 mg/kg per oral for the GAF. At increased time, the activity of most of the extracts reduced considerably. The egg-albumin induced inflammation was inhibited by the extracts as well in different doses. There were considerable inhibition for the GAF as well as the GASB at a minimum significant value of p<0.05 from the 1st h to the 4th h with maximum percentage inhibition (PI) values ranging between 30% to a peak of 70% when compared to the control. The methanolic extract of G. arborea fruit and stem bark showed significant (p<0.05) anti-inflammatory activity.
Conclusions: This study has shown that GASB and GAF displayed significant anti-inflammatory effect on paw oedema induced by egg-albumin by inhibiting the release of mediators for the entire 4 h experimental period. The anti-nociceptive actions were also significant when compared with the control.