Anti-inflammatory activities, triterpenoids, and diarylheptanoids of Alnus acuminata ssp arguta

Context: The main use of stem bark infusions of Alnus acuminata ssp. arguta (Schlecht.) Furlow (Betulaceae) includes treatments for acute inflammation in Mexican traditional medicine. Objective: n-Hexane (CHE), chloroform (CCE), and methanol (CME) extracts of the stem bark were investigated for anti-inflammatory activity and its safety. Materials and methods: The anti-inflammatory effects of the orally administered CME, CCE, and CHE extracts, using carrageenan-induced rat hind paw edema model, and acute oral toxicity in mice, using Lorke's method, were determined. Results and discussion: The column chromatographic fraction (CME-3) showed a higher anti-inflammatory activity (92.2%) (IC50 : 60.8 mg/mL) as compared with CME (76.9%); both were in the same order of magnitude as that of indomethacin, the positive control drug. Safety parameters for acute oral toxicity test showed that CME was not toxic (LD50 : >5000). Several triterpenoids (1-7) from hexane extracts and diarylheptanoids (10-14) from methanol extracts of A. acuminata ssp. arguta were isolated and characterized. Conclusions: These results confirm the traditional uses of A. acuminata in acute inflammatory conditions and its safety for consumption.