Objective: Some species of the Russelia genus have been used different illnesses associated with pain and inflammation. The aim of this work was to characterize the biological activities (anti-inflammatory and analgesic) and antioxidant capacity of methanol and dichloromethane extracts of Russelia coccinea.
Materials and methods: In this study, topical anti-inflammatory activity was tested in an in vivo model of 12-O-tetradecanoylphorbol acetate (TPA) induced mouse ear edema of organic extracts (doses: 0.03, 0.1 and 0.3 mg/ear). The antinociceptive activity was assessed using the formalin test in mice of organic extracts (doses: 56, 100 and 300 mg/kg). Moreover, the antioxidant capacity of the extracts was determined using 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2'-azinobis (3-ethylbenzothiaziline-6-sulfonate) (ABTS) and ferric reducing antioxidant power (FRAP) assays.
Results: Methanol (RcM) and dichloromethane (RcD) extracts of the R. coccinea aerial parts were found to inhibit ear edema (48.95 and 40.13%, respectively) at a dose of 0.3 mg/ear. Acute treatment with RcM produced a significant antinociceptive effect in the late phase of formalin-induced nociception. Moreover, RcM at doses of 56, 100 and 300 mg/kg showed a significant antinociceptive effect through the early and late phases in the formalin test. RcM and RcD showed weak antioxidant capacities in the ABTS and DPPH assays; however, when their reducing capacity was evaluated by the FRAP assay, RcM showed a reducing activity similar to Camellia sinensis standard at the proven concentration of 1000 μg/ml.
Conclusion: According to the experimental findings, the organic extracts of R. coccinea display remarkable antinociceptive and anti-inflammatory activities.
Keywords: Anti-inflammatory activity; Antinociceptive activity; Antioxidant; Organic extracts; Plantaginaceae; Russelia coccinea.