Lantana canescens (Kunth) inhibits inflammatory and hyperalgesic responses in murine models

Lantana canescens is popularly known in Brazil as "cidreirinha" or "chumbinho-branco". It is found in Pantanal biome and its flowers and leaves are used in traditional medicine to treat pain and inflammation. Information about this species is limited to the activity of isolated essential oils. Studies with different extracts, composition, and biological properties are still scarce.

The objective of this study was to evaluate the anti-inflammatory and anti-hyperalgesic activity of the hydroethanolic extract of L. canescens aerial parts.

The hydroethanolic extract L. canescens aerial parts (HELc) was analyzed using HPLC-DAD-EM. Male and female Swiss mice weighing 18-25 g were used in the in vivo assays. Acute toxicity was assessed (2000 mg/kg); anti-inflammatory activity through paw edema, mast cell degranulation and peritonitis, and anti-hyperalgesic activity through abdominal writhing assays induced by acetic acid and formalin sensitization, were evaluated using the doses of 3, 30 and 300 mg/kg.

The phytochemical characterization of HELc confirmed the presence of glycosylated iridoids (theveside, theviridoside), verbascosides and flavonoids. The HELc did not present toxicity in the evaluated dose. HELc reduced formation of paw edema, degranulation of peritoneal mast cells and infiltration of polymorphonuclear cells into the animals peritoneal cavity. In addition, HELc decreased the number of abdominal writhing induced by acetic acid and the time of paw licking in the evaluation of formalin sensitization.

These results confirm the anti-inflammatory and anti-hyperalgesic effects of hydroethanolic extract of L. canescens, validating the use of this plant in folk medicine.