IN VIVO ANTI-INFLAMMATORY AND ANTIOXIDANT EFFECTS OF PILIOSTIGMA RETICULATUM LEAF EXTRACT ON CARRAGEENAN-INDUCED PAW EDEMA IN WISTAR RATS

Inflammation underlies many chronic diseases, and conventional anti-inflammatory drugs are limited by adverse effects and cost. Piliostigma reticulatum is used in African traditional medicine for inflammatory conditions, yet its leaves have not been pharmacologically evaluated. This study investigated the anti-inflammatory and antioxidant effects of P. reticulatum leaf extract in carrageenan-induced paw edema in Wistar rats. Thirty rats were allocated to five groups: distilled water control, piroxicam (10 mg/kg), and extract at 800, 400, or 200 mg/kg. Paw thickness was measured for 4 hr after carrageenan injection, and serum interleukin-1 (IL-1), interleukin-10 (IL-10), C-reactive protein (CRP), malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione (GSH), and catalase (CAT) were assayed. Control paw swelling increased to 3.10 ± 0.06 mm by 4 hr. All extract doses reduced edema relative to control at every time point (p < .01 to p < .001); the 400 mg/kg dose was most effective (−0.05 ± 0.02 mm at 4 hr), numerically exceeding piroxicam (0.59 ± 0.09 mm), whereas the effect of 200 mg/kg waned after 2 hr. IL-10 was significantly lower in all treated groups than in controls, IL-1 was lower but not significantly so, and CRP was higher in treated groups. MDA was significantly reduced by the 800 mg/kg extract (p < .05) and by piroxicam (p < .01), whereas changes in SOD, GSH, and CAT were not significant. These findings provide preliminary evidence that P. reticulatum leaf extract has anti-edematous and lipid peroxidation-lowering activity, accompanied by an atypical cytokine profile that warrants mechanistic investigation.