Anti-inflammatory and antipyretic effects of Sonchus oleraceus in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Sonchus oleraceus L. has been used to relieve headaches, general pain, hepatitis, infections, inflammation and rheumatism in Brazilian folk medicine. Nevertheless, scientific information regarding this species is scarce; there are no reports related to its possible anti-inflammatory effects.

AIM OF THE STUDY: This study was aimed at evaluating the scientific basis for the traditional use of Sonchus oleraceus using in vivo inflammatory models.

MATERIALS AND METHODS: Carrageenan-induced paw edema, peritonitis and febrile response induced by lipopolysaccharide tests, as well as fibrovascular tissue growth induced by s.c. cotton pellet implantation were used to investigate the anti-inflammatory activity of Sonchus oleraceus hydroethanolic extract (SoHE) in rats.

RESULTS: The SoHE at test doses of 100-300 mg/kg p.o. clearly demonstrated anti-inflammatory effects by reduced paw edema induced by carragenan, inhibited leukocyte recruitment into the peritoneal cavity and reduced LPS-induced febrile response, and in the model of chronic inflammation using the cotton pellet-induced fibrovascular tissue growth in rats, the SoHE significantly inhibited the formation of granulomatous tissue. The extract administered at 300 mg/kg p.o. had a stronger anti-inflammatory effect than indomethacin (10mg/kg) or dexamethasone (1mg/kg).

CONCLUSION: The hydroethanolic extract of Sonchus oleraceus markedly demonstrated anti-inflammatory action in rats, which supports previous claims of its traditional use.