Hypoglycemic effects of sesquiterpene glycosides and polyhydroxylated triterpenoids of Eriobotrya japonica.

The effects of the constituent sesquiterpene glycosides 1-3 and polyhydroxylated triterpenoids 5-6 isolated by MeOH extraction of Eriobotrya japonica were studied in genetically diabetic mice (C57BL/KS-db/db/Ola) and normoglycemic rats. The sesquiterpene glycoside 3 and the polyhydroxylated triterpenoids 5 and 6 produced a marked inhibition of glycosuria. Furthermore, 5 and 6 were able to reduce blood glucose levels in normoglycemic rats. While there are already some data reported on hypoglycemic activity of polyhydroxylated triterpenoids, there are no previous data showing hypoglycemic activity of sesquiterpene glycosides.