Alzheimer's disease, also known as Alzheimer's disease, is a primary degenerative disease of the central nervous system. Patients' intelligence, memory and cognitive functions are gradually reduced, and eventually lose the ability to think, speak and move. These have seriously affected the quality of life of the elderly, but also brought a lot of burden to the family. It is found that salvianolic acid B, an extract of Salvia miltiorrhiza, has a significant preventive and therapeutic effect on Alzheimer's disease.

    One of the main pathological features of patients with Alzheimer's disease is the presence of a large number of senile plaques in the cerebral cortex and hippocampus, the main component of which is β - amyloid protein (β -ap). The aggregation and fibrosis of β -ap are important pathological changes in the brain of patients with Alzheimer's disease. It is precisely because of this change that a series of pathological reactions of Alzheimer's disease are triggered, resulting in neuron loss and dementia. β -ap fiber formation is the prerequisite for β -ap neurotoxicity. Salvianolic acid B can significantly inhibit β -ap aggregation and fiber formation, and can also significantly improve the cytotoxicity of aging β -ap.

        Cerebral ischemia is a neurological disease characterized by decreased microcirculatory blood flow and impaired glucose / energy metabolism. The key factors in the early stage of ischemic brain injury are dysregulation of cellular calcium homeostasis, excitotoxicity, excessive production of free radicals, mitochondrial dysfunction and energy depletion. Delayed neuronal death and delayed inflammation occurred in the middle and late stage of cerebral ischemia. Accompanied with nerve cell injury and death are the loss of nerve symptoms, the decline of memory and cognitive ability, cerebral infarction and brain edema. In the early stage of cerebral ischemia, the compensatory function of mitochondria was enhanced, and the mitochondrial membrane potential (MMP) was significantly increased. Salvianolic acid B could alleviate the increase of MMP and stabilize the mitochondrial membrane potential. After cerebral ischemia, energy failure is mainly manifested in the depletion of high-energy phosphate compounds ATP and creatine phosphate. Due to lack of energy, na+-k+-atp cannot operate normally, resulting in intracellular na+ accumulation and cell edema. At the same time, the activity of ATP dependent ca+-atp also decreases when ATP decreases, and ca+ cannot be pumped out of the cell, resulting in intracellular calcium overload. Salvianolic acid B can significantly increase the brain energy charge value and the content of PCR, enhance the activities of na+-k+-atpase and ca+-atpase, improve the energy metabolism of cerebral ischemia, and protect ischemic neuron damage. It is found that salvianolic acid B can increase the number of 5-bromodeoxyuridine nucleoside cells in the subventricular layer and the subgranular layer of the dentate gyrus of hippocampus in rats with cerebral ischemia, improve the injury of nerve cells in the ischemic area, and promote the recovery of limb function, suggesting that promoting neurogenesis is an important link for salvianolic acid B to improve brain function. Salvianolic acid B can also reduce the consumption of antioxidant enzymes in the brain tissue of rats with ischemia-reperfusion injury, relatively enhance its ability to scavenge oxygen free radicals, and reduce the severity of free radical attack on cells, thus reducing the damage of brain tissue, which has a neuroprotective effect.

        At present, the drugs for the prevention and treatment of senile dementia are symptomatic treatment, and the effect is not ideal. With the continuous extension of human life, the incidence of Alzheimer's disease is also increasing. It is urgent to develop new drugs that are superior to existing drugs.salb As a traditional Chinese medicine extract, it has less side effects, and has a superior research, development and application prospect