Hypoglycaemic effects of tea extracts and ent-kaurenoic acid from Smallanthus sonchifolius

Abstract

Hypoglycaemic activity was observed in normoglycaemic mice orally administered with the aqueous Smallanthus sonchifolius leaf tea extract, alloxan-induced diabetic mice orally administered with ent-kaurenoic acid (1), and normoglycaemic mice intraperitoneally administered with 1 from S. sonchifolius leaves. A single dose administration of 50 mg kg⁻¹ BW yacon leaf tea extract demonstrated immediate but relatively short hypoglycaemic activity, with significant effects observed during 1–2 h. Similarly, administration with 100 mg kg⁻¹ BW yacon leaf tea extract obtained by heavy stirring in hot water demonstrated a more potent activity compared to the positive control at 1.5–2.0 h. Oral administration of 1 did not affect the blood glucose level of the alloxan-induced diabetic mice, but a single intraperitonial injection of 10 mg kg⁻¹ BW in normoglycaemic mice had consistent percent blood glucose reduction persisting from 1 to 2 h observation periods.

Keywords:

• Smallanthus sonchifolius
• Asteraceae
• yacon
• ent-kaurenoic acid
• hypoglycaemic

Acknowledgement

Research grants from the College Research Fund, College of Science and the University Research Coordination Office of De La Salle University–Manila are gratefully acknowledged.