Involvement of Normalized Glial Fibrillary Acidic Protein Expression in the Hippocampi in Antidepressant-Like Effects of Xiaoyaosan on Chronically Stressed Mice.

The research has only yielded a partial comprehension of MDD and the mechanisms underlying the antidepressant-like effects of XYS. Therefore, in this study, we aimed to explore the effects of XYS on chronic unpredictable mild stress- (CUMS-) induced changes in the neuronal and the astrocytic markers in the mouse hippocampus. The physical states and depressive-like behaviors in mice with CUMS were recorded. The serum contents of brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) were measured. The protein and mRNA expressions and the immunoreactivities of glial fibrillary acidic protein (GFAP) and neuronal nuclei (NeuN) in mouse hippocampus were detected using a Western blot, qRT-PCR, and immunohistochemical staining, respectively. XYS treatment markedly improved the physical state and depressive-like behaviors in mice subjected to CUMS compared with the model group, and the serum contents of BDNF and GDNF were significantly upregulated. XYS treatment also elevated the protein and mRNA levels, as well as the immunoreactivity of GFAP in the hippocampus. However, CUMS did not influence NeuN expression. In conclusion, these results reveal that chronic administration of XYS elicits antidepressant-like effects in a mouse model of depression and may normalize glial fibrillary acidic protein expression in the hippocampi of mice with CUMS.

TCM Formula Xiaoyaosan Decoction Improves Depressive-Like Behaviors in Rats with Type 2 Diabetes.

The mechanism of depression with type 2 diabetes remains elusive, requiring further study. Objective. To evaluate the effect of TCM formula Xiaoyaosan on depressive-like behaviors in rats with type 2 diabetes. Methods. Rats were divided into 5 groups and drugs were administered during the model period of 21 days. The model of depressive-like behaviors in rats with type 2 diabetes was induced by a high fat diet, low doses of STZ injection, and chronic restraint stress for 21 days. The body weight, fasting blood glucose, ITT, OGTT, 5-HT, DA, depression behaviors, and morphological changes of formation were measured and observed. Results. After modeling, marked changes were found in model rats; behavioral analyses of rats indicated that this modeling method negatively impacts locomotor function. In the H&E staining, changes were found predominately in the CA1 and DG subregions of the hippocampus. After 21 days of treatment by fluoxetine and Xiaoyaosan, rats' body weights, behaviors and fasting blood glucose, and hippocampal formation were modified. Conclusions. A new model of depressive-like behaviors in rats with type 2 diabetes was successfully created. Xiaoyaosan and fluoxetine in this study independently contribute to exacerbate the disease progression.

[Establishment and evaluation of a rat model of type 2 diabetes associated with depression].

OBJECTIVE: To establish and evaluate a rat model of type 2 diabetes mellitus (T2DM) associated with depression for further elaborating the disease. METHODS: Twenty-four Wistar rats were randomly divided into three groups: normal group (group N), T2DM group (group T) and T2DM with depression group (group T + D), with 8 rats in each group. The T2DM rat model was induced by high fat diet and low dose of Streptozotocin (STZ) injection, and in addition, the T2DM rats were made restraint stress for 21 days. After the model was established, the insulin tolerance test (ITT) and oral glucose tolerance test (OGTT) were performed. Then the rat depression level was analyzed by open field test, and the concentration of 5-hydroxytryptamine (5-HT) and dopamine (DA)was determined by ELISA to confirm the model identity. RESULTS: The blood glucose level in group T and group T + D didn't return to the normal level at 180 minutes in the ITT and OGTT test; Compared with the group N, the max movement distance, retaining time in the central zone and the retaining frequency within 5 minutes in the group T + D decreased; 5-HT and DA level in the serum of rats in. group T + D was reduced. CONCLUSION: A rat model of type 2 diabetes mellitus associated with depression has been successfully established by high fat diet and injection of low dose streptozotocin in combination with restraint stress for 21 days. This rat model is useful for further relevant studies.

Neuropeptide Y and leptin receptor expression in the hypothalamus of rats with chronic immobilization stress.

In this study, Sprague-Dawley rats were immobilized to a frame for 3 hours a day for 21 days to establish a model of chronic immobilization stress. The body weight and food intake of rats subjected to chronic immobilization stress were significantly decreased compared with the control group. Dual-labeling immunofluorescence revealed that the expression of leptin receptor and the co-localization coeffient in these leptic receptor neurons in the arcuate nucleus of the hypothalamus were both upregulated, while the number of neuropeptide Y neurons was decreased. Chronic immobilization stress induced high expression of leptin receptor in the arcuate nucleus and suppressed the synthesis and secretion of neuropeptide Y, thereby disrupting the pathways in the arcuate nucleus that regulate feeding behavior, resulting in diminished food intake and reduced body weight.

Xiaoyaosan decoction regulates changes in neuropeptide y and leptin receptor in the rat arcuate nucleus after chronic immobilization stress.

The arcuate nucleus (ARC) in the basal of hypothalamus plays an important role in appetite regulation and energy balance. We sought to investigate the central neuroendocrine mechanism of appetite decrease and weight loss under chronic stress by observing the regulatory effects of Xiaoyaosan decoction in the expression of leptin receptor (ob-R) and neuropeptide Y (NPY) in the ARC. Our results showed that bodyweight and food intake of rats in the 21-day stress group increased slower than those of the normal group. Higher contents of Leptin and ob-R were noted in the 21-day stress group compared with control rats, while NPY expression was not statistically different. Xiaoyaosan powder can significantly downregulate the contents of leptin and ob-R in the hypothalamus of stressed rats. These findings suggest that increase of ob-R expression in the ARC is possibly one key central neuroendocrine change for the somatic discomfort. Weight loss and decreased food intake in rats caused by the binding of leptin to ob-R in hypothalamus do not appear to utilize the NPY pathway. This study also suggests that ob-R in the ARC may act as the target of Xiaoyaosan in regulating the symptoms such as appetite decrease and bodyweight loss under chronic stress.