Identification of hypoglycaemic compounds from berries of Juniperus oxycedrus subsp. oxycedrus through bioactivity guided isolation technique.

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE Decoction of Juniperus oxycedrus subsp. oxycedrus L. (Cupressaceae) berries is used internally as tea and pounded fruits are consumed to lower blood glucose levels in Turkey. AIM OF THE STUDY To evaluate hypoglycaemic and antidiabetic activity of J. oxycedrus subsp. oxycedrus berries and to identify active compounds through bioactivity guided isolation technique. MATERIAL AND METHODS: Hypoglycaemic effect of J. oxycedrus subsp. oxycedrus (Joso) berry extracts on oral administration was studied using in vivo models in normal, glucose-hyperglycaemic rats. Streptozotocin induced diabetic rats were used to examine antidiabetic activity of Joso extracts, subextracts, fractions, subfractions and shikimic acid (SA). RESULTS: Through in vivo bioactivity-guided fractionation processes, shikimic acid, 4-O-ß-d-glucopyranosyl ferulic acid and oleuropeic acid-8-O-ß-d-glucopyranoside were isolated from the n-butanol subextract by silica gel and reverse phase column chromatography as the main active ingredient of the active subfraction. After 8 days administration of the major compound shikimic acid, blood glucose levels (24%), malondialdehyde levels in kidney tissues (63-64%) and liver enzymes (AST, ALT, ALP) of diabetic rats were decreased. CONCLUSION: Results indicated that Joso berry extract and its active constituents might be beneficial for diabetes and its complications.