Ice plant (Mesembryanthemum crystallinum) improves hyperglycaemia and memory impairments in a Wistar rat model of streptozotocin-induced diabetes.

BACKGROUND

Ice plant (Mesembryanthemum crystallinum) has been used as an anti-diabetic agent in Japan because it contains d-pinitol. The efficacy of ice plant in the regulation of blood glucose is unclear at present. Recently, memory impairment and development of Alzheimer's disease found in diabetic patients are thought to be caused by high blood glucose. The mechanism by which ice plant protects against the impairment of memory and learning abilities caused by high blood glucose remains unclear. The aim of this study was to evaluate the protection of ice plant water extracts (IPE) and D-pinitol against memory impairments in a Wistar rat model of streptozotocin (STZ)-induced diabetes. We hypothesised that IPE and D-pinitol could suppress blood glucose and elevate insulin sensitivity in these rats.

RESULTS

For memory evaluation, IPE and D-pinitol also improved the passive avoidance task and the working memory task. In addition, inhibition of acetylcholinesterase activity in hippocampus and cortex was found in this rat model administered IPE or D-pinitol. IPE and D-pinitol also markedly elevated superoxide dismutase activity against oxidative stress and reduced malondialdehyde production in hippocampus and cortex of the rats.

CONCLUSIONS

These findings indicated that IPE and D-pinitol possess beneficial effects for neural protection and memory ability in a rat model of diabetes.