Chotosan and cerebrovascular disorders: Clinical and experimental studies

We reviewed our prior clinical and experimental studies about the effects of chotosan, a Kampo formula, on cerebrovascular disorders. A double-blind randomized controlled trial demonstrated that chotosan was effective on vascular dementia. Chotosan improved microcirculation and hemorheological factors in patients with asymptomatic cerebral infarction. This formula inhibited the elevation of blood pressure, protected endothelial function, and prolonged the life span of stroke-prone spontaneously hypertensive rats. The phenolic fraction of Uncaria sinensis (US), a main medicinal plant of chotosan, had endothelium-dependent relaxation effect, and its alkaloid fraction possessed endothelium-independent relaxation effect. It was revealed that US had neuroprotective effects on glutamate- and NO donor-induced neuronal death in cultured neurons. Chotosan and US had protective effects on delayed neuronal death after transient forebrain ischemia in gerbils, and enhanced superoxide anion and hydroxyl radical scavenging activities and catalase activity in the brain. All of these results suggest that chotosan has such multiple pharmacological actions as improving effect on microcirculation, protective effect on endothelial function, and neuroprotective effect, and this formula is useful for prevention of the development of cerebrovascular disorders.