Antiinflammatory and antinociceptive activities of extracts and isolated compounds from Stachytarpheta cayennensis.

The alcoholic and n-butanolic extracts of dried leaves of Stachytarpheta cayennensis (L.C. Rich) Vahl (Verbenaceae) was assessed in antiinflammatory and antinociceptive models. Intraperitoneal pretreatment with the dried extracts at doses ranging from 100 to 200 mg/kg, significantly inhibited carrageenin inducing edema formation. The active extracts were then fractionated and monitored with the same bioassay. The iridoid ipolamiide and the phenylethanoid glycoside acteoside were isolated from the active fraction and showed inhibitory effect on histamine and bradykinin induced contractions of guinea-pig ileum. The compounds also showed in vivo antiinflammatory activity when administered orally to rats mainly in the fourth hour after the administration of the phlogistic agent (70.22% and 93.99%, respectively). These results indicate that S. cayennensis shows antiinflammatory properties which seems to be due, at least partly, to the inhibition of bradyknin and histamine. The extracts also exhibited antinociceptive activity measured by the hot-plate test both i.p. and p.o. in doses ranging from 100 to 300 mg/kg.