Total flavonoids of Astragalus protects glomerular filtration barrier in diabetic kidney disease.

BACKGROUND: Diabetic kidney disease (DKD) is a prevalent complication of diabetes and the leading cause of end-stage renal disease. Recent evidence suggests that total flavonoids of Astragalus (TFA) has promising effects on diabetes; however, its influence on DKD and the underlying mechanism remains unclear. METHODS: In this study, we induced the DKD model using streptozotocin (STZ) in male C57BL/6J mice and utilized glomerular endothelial cell (GEC) lines for in vitro investigations. We constructed a network pharmacology analysis to understand the mechanism of TFA in DKD. The mechanism of TFA action on DKD was investigated through Western blot analysis and multi-immunological methods. RESULTS: Our findings revealed that TFA significantly reduced levels of urinary albumin (ALB). Network pharmacology and intracellular pathway experiments indicated the crucial involvement of the PI3K/AKT signaling pathway in mediating these effects. In vitro experiments showed that TFA can preserve the integrity of the glomerular filtration barrier by inhibiting the expression of inflammatory factors TNF-alpha and IL-8, reducing oxidative stress. CONCLUSION: Our findings demonstrated that TFA can ameliorates the progression of DKD by ameliorating renal fibrosis and preserving the integrity of the kidney filtration barrier. These results provide pharmacological evidence supporting the use of TFA in the treatment of kidney diseases.

Total flavonoids of Astragalus Ameliorated Bile Acid Metabolism Dysfunction in Diabetes Mellitus.

Astragalus Radix is one of the common traditional Chinese medicines used to treat diabetes. However, the underlying mechanism is not fully understood. Flavones are a class of active components that have been reported to exert various activities. Existing evidence suggests that flavones from Astragalus Radix may be pivotal in modulating progression of diabetes. In this study, total flavones from Astragalus Radix (TFA) were studied to observe its effects on metabolism of bile acids both in vivo and in vitro. C57BL/6J mice were treated with STZ and high-fat feeding to construct diabetic model, and HepG2 cell line was applied to investigate the influence of TFA on liver cells. We found a serious disturbance of bile acids and lipid metabolism in diabetic mice, and oral administration or cell incubation with TFA significantly reduced the production of total cholesterol (TCHO), total triglyceride, glutamic oxalacetic transaminase (AST), glutamic-pyruvic transaminase (ALT), and low-density lipoprotein (LDL-C), while it increased the level of high-density lipoprotein (HDL-C). The expression of glucose transporter 2 (GLUT2) and cholesterol 7α-hydroxylase (CYP7A1) was significantly upregulated on TFA treatment, and FXR and TGR5 play pivotal role in modulating bile acid and lipid metabolism. This study supplied a novel understanding towards the mechanism of Astragalus Radix on controlling diabetes.

Transducible P11-CNTF rescues the learning and memory impairments induced by amyloid-beta peptide in mice.

Alzheimer's disease is a progressive brain disorder with the loss of memory and other intellectual abilities. Amyloid species and neurofibrillary tangles are the prime suspects in damaging and killing nerve cells. Abnormal accumulation of Amyloid-beta peptide (Abeta) may cause synaptic dysfunction and degeneration of neurons. Drugs that can prevent its formation and accumulation or stimulate its clearance might ultimately be of therapeutic benefit. Ciliary neurotrophic factor (CNTF), a neurotrophic cytokine, promotes the survival of various neurons in brain. However, the blood-brain barrier hinders the systemic delivery of CNTF to brain. Recently the 11-amino acid of protein transduction domain TAT has successfully assisted the delivery of many macromolecules to treat preclinical models of human disease. The present study aimed to evaluate whether P11-CNTF fusion protein (P11-CNTF) is protective against the Abeta25-35-induced dementia in mice. Immunofluorescence experiments showed that P11 effectively carried CNTF to the SH-SY5Y cells in vitro, and to the brains of mice in vivo. The learning and memory impairments of mice induced by Abeta were substantially rescued by supplement with the P11-CNTF. Furthermore, mRNAs of enzymes involved in the Abeta metabolism, e.g. neprilysin (NEP), endothelin-converting enzyme 1 (ECE-1) and insulin degrading enzyme (IDE), increased in the P11-CNTF treated dementia mice, accompanied by the proliferation of nestin- and choline acetyltransferase (ChAT)-positive cells in hippocampus. It implies that the delivery of P11-CNTF may be a novel treatment for Alzheimer's disease.

Effects of Chinese herbal medicine Fuzhisan on autologous neural stem cells in the brain of SAMP-8 mice.

Fuzhisan (FZS), a Chinese herbal complex prescription, has been used in the treatment of Alzheimer's disease (AD) for more than 16 years. However the underlying mechanism remains to be explored. The effects of the aqueous extract of FZS on the cognitive functions of the aged mice and the pharmacological basis for its therapeutic efficacy were investigated. The results showed that FZS improved impaired cognitive ability of aged SAMP-8 mice. FZS (2.4, 4.8 g/kg/d) increased hippocampal neurogenesis and the long-term survival of BrdU-labeled cells without affecting the proportion of BrdU-positive neurons and glial cells. FZS also increased the number of BrdU-positive cells in the subventricular zone (SVZ) of the lateral ventricles of 8-month-old SAMP-8 mice. These studies suggest that FZS upregulates neurogenesis by increasing proliferation of neural progenitor cells and prolonging survival of the newborn cells in the hippocampal DG. FZS may be beneficial for the treatment of senile dementia, especially Alzheimer's disease.

Amelioration of dementia induced by Aß 22-35 through rectal delivery of undecapeptide-hEGF to mouse brain.

A group of growth factors have been shown to play important roles in amelioration of the malfunction of the neurodegenerative diseases. However, the proteins or polypeptides passing across the blood-brain barrier (BBB) to access the brain parenchyma are relatively few so that it hinders the therapies in clinic. Here a genetically reconstructed fusion peptide of human epidermal growth factor (hEGF) with an undecapeptide YGRKKRRQRRR (P11) was used to investigate the permeability between the cell membrane and the BBB via rectal administration. The efficiency to rescue the Aß 22-35-induced dementia in mice was assessed after administration of P11-hEGF per rectal. Our results showed that P11-hEGF permeates across not only the 3T3 cell membrane in vitro, but also the endothelia of vessels after intravenous injection (IV), and the mucosa of the rectum after per rectal administration. Further results showed that the circulating P11-hEGF allowed penetrating through the blood-brain barrier and then getting into the brain manifesting biological responses. In the animal experiments, treatment with P11-hEGF not only ameliorated the dementia induced by Aß 22-35 but also rescued the dementia of the aged mice, no matter how it was administrated (IV or per rectal). These results suggest that the rectal non-invasive delivery of the P11 polypeptide-conjugated growth factor is an efficient way for BBB transduction, thus raises the hope of real therapeutic progress against neurodegenerative diseases.

Changes of autologous neural stem cells in the hippocampi of aging mice.

Although there is possibility of cognitive disturbance in aging people, many of them live for long life and enjoy well-functioning brain during the whole life-span. The biological basis of longevity is unknown. In this study, we investigated the influence of aging on hippocampal neural stem cells (NSCs), and the correlations between hippocampal neurogenesis and cognitive function. The result showed that the protein production and mRNA expression of nestin, and the number of BrdU(+) cells in dentate gyrus (DG) of the aged non-dementia mice were clearly higher than that in the aged dementia mice and the young adult mice. We also found that the number of NeuN(+) (neuron-specific nuclear antigen) cells in DG and CA1, choline O-acetyltransferase (ChAT, EC 2.3.1.6) production and mRNA expression in hippocampi of the aged-dementia mice were significantly reduced as compared to that of the young adult mice and the aged non-dementia mice, whereas the number of NeuN(+) cells, ChAT production and mRNA expression of the aged non-dementia mice has no difference with that of the young adult mice. Glial fibrillary acidic protein (GFAP) expression in the hippocampi of aged dementia mice significantly higher than that of the young adult mice and the aged non-dementia mice. Our results suggest that aging sometimes does not cause changing of the number of neurons and the hippocampal neurogenesis. Increment of DNA replication and neuron replacement, promotion of differentiation of neural stem cells, enhancement of neuronal proliferation, facilitation of synaptic plasticity of neurons may all benefit to the maintenance of the normal cognitive ability in the aged mice.

Effects of Chinese herbal medicine fuzhisan on aged rats.

Fuzhisan (FZS), a Chinese herbal complex prescription, has been used in the treatment of Alzheimer's disease (AD) for more than 15 years. Previous studies showed that FZS enhanced the cognitive ability in AD patients and AD model rats. FZS modulated the impaired cellular functions, and attenuated the damage caused by beta-amyloid protein, dose-dependently regulated and ameliorated the cholinergic functions of the Abeta(25-35)-induced AD-model mice. The SPECT imaging revealed that FZS improved the blood flow of the frontal and temporal lobes and the callosal gyrus in AD patients. However, little investigation of the effects of FZS on the naturally aged rats was reported. The underlying mechanism also remains to be explored. Recently we investigated the effects of the aqueous extract of FZS on the cognitive functions of the aged rats and the pharmacological basis for its therapeutic efficacy. The results showed a significant improvement made by FZS (0.3, 0.6, and 1.2 g/kg/d) for impaired cognitive functions of the aged rats. The rats manifested a shortened latency in Morris water maze test after intra-gavage administration (ig) of FZS for 30 consecutive days. The micro-positron emission tomography (microPET) using (18)F-2-fluoro-2-deoxy-D-glucose ((18)F-FDG) as the tracer demonstrated that FZS promoted the glucose metabolism in the whole brains especially the temporal and parietal regions in the aged rats. The spectrophotometry and Western blot showed that FZS obviously increased the activity and the production of choline O-acetyltransferase (ChAT, EC 2.3.1.6) and the acetylcholine (ACh) contents in the hippocampus, thus regulated and ameliorated the impaired cholinergic functions of the aged rats. The therapeutical effects of FZS on the learning and memory of the aged rats were dose-dependent. The mechanism of action of FZS in ameliorating the memory dysfunction of the aged rats is ascribed to the reinforcement of the function of the cholinergic system and the enhancement of the glucose metabolism in the brains. The results of this study, together with a survey of the findings in the clinical treatment with FZS suggest that FZS may not merely alleviate the symptoms of the dementia, but may also augment the production of the neurotransmitter ACh and the energy supply in the brain to build up fitness of the patients. FZS may be beneficial for the treatment of Alzheimer's disease or cognitive impairment in old people.