Hypoglycaemic effects of Ajuga extract in vitro and in vivo

The Ajuga species with abundant flavonoids, terpenoids and other active compounds might be a potential remedies for diabetes. In this study, we used five common Ajuga species in Taiwan, including A. decumbens, A. nipponensis, A. pygmaea, A. taiwanensis and A. dictyocarpa, to determine the hypoglycaemic effects of the extracts in vitro and in vivo. Amongst the five Ajuga species, A. nipponensis contained the highest content of flavonoids (7.76 +/- 0.21 mg/g) and ecdysterone (0.785 +/- 0.031 mg/g). In addition, ultrasonic-assisted extraction (UAE) produced better yield than supercritical fluid extraction (SFE). Furthermore, A. nipponensis has the best effect in alpha-glucosidase inhibition (28.62 +/- 1.56%) and glucose uptake (54.15 +/- 2.56%). Subsequent STZ (streptozotocin)-induced diabetic mice administration of A. nipponesis extracts (200 mg/kg BW) moderately decreased postprandial blood glucose levels in. Thus, A. nipponensis extracts may be a potential remedy for diabetes in the future. (C) 2013 Elsevier Ltd. All rights reserved.