Anti-inflammatory and antinociceptive properties of Handroanthus heptaphyllus (Vell.) Mattos hydroethanolic extract bark in mice

Handroanthus heptaphyllus (Vell.) Mattos (Bignociaceae), popularly known in Brazil as "ipê-roxo" or "lapacho", is native to the Pantanal biome (Brazil). Its bark is traditionally used to treat inflammation, yet no scientific evidence currently supports this ethnomedicinal use. This study aimed to characterize the phytochemical profile of the hydroethanolic extract of H. heptaphyllus bark (HhHE), to evaluate its anti-inflammatory potential, and investigate its toxicity. From HhHE, several compounds were annotated, including glycosylated iridoids and phenolics. This extract did not present cytotoxicity, and significantly reduced the in vitro neutrophil chemotaxis and phagocytosis activity. The HhHE treatment reduced mast cell degranulation, carrageenan-induced edema formation and hyperalgesia. In addition, it reduced leukocyte recruitment, pro-inflammatory cytokines, such as tumor necrosis factor (TNF), and interleukin-6 (IL-6), and nitric oxide (NO) levels in zymosan-induced peritonitis model. The HhHE treatment also inhibited nociceptive responses in the inflammatory phase of the formalin, and acetic acid-induced abdominal writhing test, without impairing locomotion. HhHE has demonstrated significant anti-inflammatory and antinociceptive effects, possibly through the modulation of leukocyte activity and the decrease in the levels of the inflammatory mediators, such as IL-6, TNF, and NO, corroborating its traditional use and indicating its therapeutic potential in the management of inflammation and inflammatory pain.