Abstract

Many species from the genus Lantana (Verbenaceae) have been used in traditional medicine, and their anti-inflammatory and antioxidant activities demonstrated. Lantana radula Swartz has been reported to be rich in phenylethanoid glycosides, which have various biological properties. In order to evaluate the actions of this plant, studies were performed on anti-inflammatory activity of the aqueous phase resulting from the fractioning with HP-20SS resin (AP-20SS) of L. radula roots, as well as on antioxidant capacity of its isolated phenylethanoids. Anti-inflammatory activity of the AP-20SS (30, 100, and 300 mg/kg) was evaluated using carrageenan-induced paw edema and peritonitis models. Antioxidant activity of the AP-20SS and its phenylethanoid glycosides (1 to 100 μg/ml) was evaluated by quantification of nitric oxide radical generation and lipid peroxidation. The AP-20SS reduced paw edema (100 and 300 mg/kg, p < 0.01) and leukocyte influx (30, 100, and 300 mg/kg, p < 0.001). Nitric oxide radical generation was also inhibited by the AP-20SS (IC₅₀ value of 31.16 μg/ml). L. radula AP-20SS prevented Fe²⁺- or Fe²⁺ plus H₂O₂-induced lipid peroxidation (IC₅₀ values < 1.00 μg/ml). Raduloside, samioside and isonuomioside A significantly inhibited nitric oxide radicals generation (by approximately 13%) and lipid peroxidation (by 57 to 99%). The results of the present study suggest that the anti-inflammatory effects of the AP-20SS may be related, at least in part, to the antioxidant capacity of its phenylethanoids.

Key words: Leukocyte influx, lipid peroxidation, myeloperoxidase activity, nitric oxide radical scavenging activity, paw edema.