Pharmacological and toxicological profile of extract from Heliopsis longipes and affinin

Heliopsis longipes is a popular medicinal plant in Mexico. One of the main constituents that can be extracted from H.longipes is affinin (N-isobutylamide). However, available information regarding this compound is scarce, and there is only a single report related to the effect of affinin on the central nervous system. Affinin extracted from H.longipes was evaluated for its psychopharmacological activity in several models and for its safety. H.longipes extract and affinin demonstrated antinociceptive effect, modified anxiety behavior and prolonged the time of sodium pentobarbital-induced hypnosis. Affinin elicited these activities at high doses. Both the extract and affinin decreased the time of clonic and tonic PTZ-induced seizures. In the Ames test, neither the extract nor affinin induced mutations in the Salmonella typhimurium strains TA98 and TA100 or TA102 with or without the S9 microsomal fraction. Lethal dose 50 values in mice suggest that the H.longipes extract may contain sedative principles with potential anxiolytic activity; however, it may also increase convulsive activity.