[Protective effect of Morinda citrifolia on the ischemic neuronal damage]

The fruits juice of Morinda citrifolia (Noni juice) is a well known healthy drink and has various pharmacological effects such as antioxidant. Here, we focused on the protective effect of Okinawa Noni juice (ONJ) against ischemic stress using cerebral ischemia-reperfusion model mice. We found that free intake of 10% ONJ for 7 days showed the protective effect on neuronal damage after ischemic stress, while 3% ONJ did not show such effects. It has recently reported that glucose intolerance might be induced by ischemic stress and controlling of the blood glucose levels in the early phase of ischemic stress seems to be important for good prognosis. Interestingly, we have found the glucose intolerance was developed on 1st day after ischemic stress, while it disappeared on 3rd day. On the other hand, neuronal damage gradually developed from 1st to 5th day after ischemic stress. These results indicate that development of glucose intolerance might be one of the exacerbating factors of neuronal damage after ischemic stress. Noteworthy, the development of glucose intolerance on 1st day after ischemic stress significantly suppressed by ONJ in a dose-dependent manner. These results suggest that protective effect of ONJ might be mediated by suppression of ischemic stress-induced glucose intolerance.