Garden rue inhibits the arachidonic acid pathway, scavenges free radicals, and elevates FRAP: role in inflammation.

Aim: In the present study, the anti-inflammatory and antioxidant activities of the methanol extract of Ruta graveolens leaves (RG-M) were evaluated using various in vivo and in vitro models.

Method: For anti-inflammatory activity, RG-M was administered by the oral route (p.o.) in a carrageenan-induced paw edema model, and by the intraperitoneal route (i.p.) in an exudative inflammation model. In vitro inhibition of cyclooxygenase and lipoxygenase enzymes was evaluated. In vitro antioxidant activity was also examined. Endogenous antioxidant status was further evaluated by ferric reducing ability of plasma model.

Results: RG-M showed maximum inhibition of carrageenan-induced edema (100 mg·kg⁻¹ - 33.36%; 200 mg·kg⁻¹ - 45.32% and 400 mg·kg⁻¹ - 56.28%). In the exudative inflammation model, a significant reduction in leukocyte migration (200 mg·kg⁻¹ - 54.75% and 400 mg·kg⁻¹ - 77.97%) and protein exudation (200 mg·kg⁻¹ - 31.14% and 400 mg·kg⁻¹ - 49.91%) were observed. RG-M also exhibited inhibition of COX-1 (IC50 182.27 μg·mL⁻¹) and COX-2 (IC50 190.16 μg·mL⁻¹) as well as 5-LOX (IC50 215.71 μg·mL⁻¹). Antioxidant activity was significant with improved endogenous antioxidant status.

Conclusion: The results demonstrated the anti-inflammatory and antioxidant activity of RG-M with potent inhibitory effects on the arachidonic acid pathways.