Potential synaptic plasticity-based Shenzhiling oral liquid for a SAD Mouse Model

Role of Fibrinogen in Type-2 Diabetes Mellitus with Diabetic Neuropathy and its Preliminary Mechanism

INTRODUCTION

Diabetic peripheral neuropathy (DN) is the most common complication of type 2 diabetes mellitus (T2DM).

OBJECTIVE

This study aimed to explore the role of fibrinogen (FIB) in T2DM neuropathy and its preliminary mechanism.

METHODS

Ten male Sprague-Dawley rats were divided into a normal control group (NC group) and a T2DM neuropathy model group (DN group). The DN group was given a high-energy diet and streptozotocin, while the NC group was given a normal diet and a citric acid buffer. The expression levels of related proteins were analysed.

RESULTS

Electrophysiology: Compared with the NC group, the conduction latency of the somatosensory-evoked potential and nerve conduction velocity was prolonged in the DN group, while the motor nerve action potential was decreased. As seen under a light microscope, the peripheral nerve fibres in the DN group were swollen, and the nerve fibres in the posterior funiculus of the spinal cord were loose or missing. Moreover, as seen under an electron microscope, the peripheral nerve demyelination of the DN group was severe, with microvascular blood coagulation, luminal stenosis, and collapse. Compared with the NC group, in the DN group, the expression of FIB was positively correlated with the expression of both ionised calcium-binding adaptor molecule-1 and glial fibrillary acidic protein. Compared with the NC group, in the DN group, the expression of platelet/endothelial cell adhesion molecule-1 and B-cell lymphoma 2 was negatively correlated.

CONCLUSION

The increased concentration of FIB may be the cause of neuropathy, and its mechanism may be related to its promotion of inflammatory response, blood coagulation, and vascular stenosis.

Literature review on the interdisciplinary biomarkers of multi-target and multi-time herbal medicine therapy to modulate peripheral systems in cognitive impairment

Alzheimer's disease (AD) is a chronic progressive neurodegenerative disease characterized by the deposition of amyloid-beta (Aβ) peptide and neurofibrillary tangles in the brain. The approved drug for AD has certain limitations such as a short period of cognitive improvement effect; moreover, the development of drug for AD therapeutic single target for Aβ clearance in brain ended in failure. Therefore, diagnosis and treatment of AD using a multi-target strategy according to the modulation of the peripheral system, which is not only limited to the brain, is needed. Traditional herbal medicines can be beneficial for AD based on a holistic theory and personalized treatment according to the time-order progression of AD. This literature review aimed to investigate the effectiveness of herbal medicine therapy based on syndrome differentiation, a unique theory of traditional diagnosis based on the holistic system, for multi-target and multi-time treatment of mild cognitive impairment or AD stage. Possible interdisciplinary biomarkers including transcriptomic and neuroimaging studies by herbal medicine therapy for AD were investigated. In addition, the mechanism by which herbal medicines affect the central nervous system in connection with the peripheral system in an animal model of cognitive impairment was reviewed. Herbal medicine may be a promising therapy for the prevention and treatment of AD through a multi-target and multi-time strategy. This review would contribute to the development of interdisciplinary biomarkers and understanding of the mechanisms of action of herbal medicine in AD.

Shenzhiling oral solution promotes myelin repair through PI3K/Akt-mTOR pathway in STZ-induced SAD mice

Most forms of Alzheimer's disease are sporadic. A model of sporadic Alzheimer's disease induced with bilateral intraventricular injection of streptozotocin leads to insulin resistance in the brain accompanied by memory decline, synaptic dysfunction, amyloid plaque deposition, oxidative stress, and neuronal apoptosis, all of which mimic the pathologies associated with sporadic Alzheimer's disease. Myelin injury is an essential component of Alzheimer's disease, playing a key role in early cognitive impairment. Our previously research found that sporadic Alzheimer's disease model showed myelin injury and that Shenzheling oral solution improved mild-to-moderate Alzheimer's disease; therefore, the protective effect of Shenzheling oral solution on myelin injury in early cognitive impairment is worth attention. In this study, the Morris water maze test results showed impairments in the learning and memory functions of mice in the model group, whereas the learning and memory function significantly improved after drug intervention. Immunohistochemistry showed increased β-amyloid plaques in the model group and decreased amounts in the drug group. Moreover, results of electron microscopy, western blot, and polymerase chain reaction showed that Shenzhiling oral solution improved early cognitive impairment and repaired myelin sheath damage; the potential mechanism of these effects may relate to the PI3K/Akt-mTOR signaling pathway. These findings support the application and promotion of Shenzhiling oral solution to treat sporadic Alzheimer's disease.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-02900-x.

GAPT regulates cholinergic dysfunction and oxidative stress in the brains of learning and memory impairment mice induced by scopolamine

BACKGROUND

Cholinergic dysfunction and oxidative stress are the crucial mechanisms of Alzheimer's disease (AD). GAPT, also called GEPT (a combination of several active components extracted from the Chinese herbs ginseng, epimedium, polygala and tuber curcumae) or Jinsiwei, is a patented Chinese herbal compound, has been clinically widely used to improve learning and memory impairment, but whether it can play a neuroprotective role by protecting cholinergic neurons and reducing oxidative stress injury remains unclear.

METHODS

Male ICR mice were intraperitoneally injected with scopolamine (3 mg/kg) to establish a learning and memory disordered model. An LC-MS method was established to study the chemical compounds and in vivo metabolites of GAPT. After scopolamine injection, a step-down passive-avoidance test (SDPA) and a Y maze test were used to estimate learning ability and cognitive function. In addition, ELISA detected the enzymatic activities of acetylcholinesterase (AChE), acetylcholine (ACh), choline acetyltransferase (ChAT), malondialdehyde (MDA), glutathione peroxidase (GPX), and total superoxide dismutase (T-SOD). The protein expressions of AChE, ChAT, SOD1, and GPX1 were observed by western blot, and the distribution of ChAT, SOD1, and GPX1 was observed by immunohistochemical staining.

RESULTS

After one-half or 1 month of intragastric administration, GAPT can ameliorate scopolamine-induced behavioral changes in learning and memory impaired mice. It can also decrease the activity of MDA and protein expression level of AChE, increase the activity of Ach, and increase activity and protein expression level of ChAT, SOD, and GPX in scopolamine-treated mice. After one and a half month of intragastric administration of GAPT, echinacoside, salvianolic acid A, ginsenoside Rb1, ginsenoside Rg2, pachymic acid, and beta asarone could be absorbed into mice blood and pass through BBB.

CONCLUSIONS

GAPT can improve the learning and memory ability of scopolamine-induced mice, and its mechanism may be related to protecting cholinergic neurons and reducing oxidative stress injury.

Potential synaptic plasticity-based Shenzhiling oral liquid for a SAD Mouse Model

BACKGROUND

Synaptic plasticity is the basis of memory formation. The pathological manifestations of abnormal glucose metabolism in the nervous system of sporadic Alzheimer's disease (SAD) may affect synaptic plasticity, thus causing memory damage. As a traditional Chinese medicine compound preparation, the mechanism by which Shenzhiling (SZL) oral liquid can alleviate the cognitive impairment of SAD by improving synaptic plasticity remains unclear.

OBJECTIVE

This article mainly discusses whether SZL can exert a protective synaptic effect as mediated by glutamate receptors and glycogen synthesis kinase 3β (GSK3β); further, it discusses whether SZL can improve cognitive function in SAD.

METHODS

C57BL/6 mice were used as a SAD model after injection with streptozotocin (STZ) into the bilateral lateral ventricles; mice of the same background were injected with artificial cerebrospinal fluid into bilateral ventricles and were used as a control group. After 3 months of exposure to the intervention, the step-down test was carried out. Western blot was used to detect the levels of NMDAR2B, p-NMDAR2B, mGlu5, GSK3β, and p-GSK3β in the hippocampus of mice. Immunohistochemical analysis was used to observe the number of GSK3β-positive cells in the CA1 region of mouse hippocampus.

RESULTS

The memory retention ability of mice was significantly improved after 3 months of SZL treatment, and the expression levels of NMDAR2B, mGlu5, and GSK3β were significantly changed.

CONCLUSION

Shenzhiling provides a potential for the treatment for SAD with traditional Chinese medicine.