Palmatine ameliorates LPS-induced HT-22 cells and mouse models of depression by regulating apoptosis and oxidative stress

Acute hyper-hypoxia accelerates the development of depression in mice via the IL-6/PGC1α/MFN2 signaling pathway

Background

Neural cell damage is an important cause of exacerbation of depression symptoms caused by hypoxia, but the mechanism behind it is still unclear. The purpose of this study is to elucidate the role of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α)/mitofusin-2 (MFN2) signaling axis in the development of depression in mice under hypoxia.

Methods

Male Institute of Cancer Research mice (age, 6 weeks) were assigned to the normal group, chronic unpredictable mild stress group (CUMS group), or CUMS + hyper-hypoxia group (CUMS + H group). Mice in the CUMS and CUMS + H groups were exposed to CUMS for 28 days. Additionally, mice in the CUMS + H group were exposed to acute hyper-hypoxia from Day 21 for 7 days. After a total of 28 days, behavioral experiments were conducted. All mice were anesthetized and sacrificed. Levels of brain tissue interleukin (IL)-6, reactive oxygen species (ROS), adenosine triphosphate (ATP), and serotonin (5-HT) were analyzed.

Results

As compared to the CUMS group, mice in the CUMS + H group had increased IL-6 and ROS levels, but lower open-field activity, preference for sucrose, hippocampal neuronal membrane potential, ATP, and 5-HT levels, as well as MFN2 and PGC1α levels.

Conclusions

Acute hyper-hypoxia plays an important role in the development of depression via the IL-6/PGC1α/MFN2 signaling pathway.

Analysis of the mechanism of fibrauretine alleviating Alzheimer's disease based on transcriptomics and proteomics

The dried rattan stem of the Fibraurea Recisa Pierre plant contains the active ingredient known as fibrauretine (FN). Although it greatly affects Alzheimer's disease (AD), the mechanism of their effects still remains unclear. Proteomics and transcriptomics analysis methods were used in this study to determine the mechanism of FN in the treatment of AD. AD model is used through bilateral hippocampal injection of Aβ1-40. After successful modeling, FN was given for 30 days. The results showed that FN could improve the cognitive dysfunction of AD model rats, reduce the expression of Aβ and P-Tau, increase the content of acetylcholine and reduce the activity of acetylcholinesterase. The Kyoto Encyclopedia of Genes and Genomes enriched differentially expressed genes and proteins are involved in signaling pathways including metabolic pathway, AD, pathway in cancer, PI3K-AKT signaling pathway, and cAMP signaling pathway. Transcriptomics and proteomics sequencing resulted in 19 differentially expressed genes and proteins. Finally, in contrast to the model group, after FN treatment, the protein expressions and genes associated with the PI3K-AKT pathway were significantly improved in RT-qPCR and Western blot and assays. This is consistent with the findings of transcriptomic and proteomic analyses. Our study found that, FN may improve some symptoms of AD model rats through PI3K-AKT signaling pathway.

Pharmacological mechanism of natural antidepressants: The role of mitochondrial quality control

BACKGROUND

Depression is a mental illness characterized by persistent sadness and a reduced capacity for pleasure. In clinical practice, SSRIs and other medications are commonly used for therapy, despite their various side effects. Natural products present distinct advantages, including synergistic interactions among multiple components and targeting multiple pathways, suggesting their tremendous potential in depression treatment. Imbalance in mitochondrial quality control (MQC) plays a significant role in the pathology of depression, emphasizing the importance of regulating MQC as a potential intervention strategy in addressing the onset and progression of depression. However, the role and mechanism through which natural products regulate MQC in depression treatments still need to be comprehensively elucidated, particularly in clinical and preclinical settings.

PURPOSE

This review was aimed to summarize the findings of recent studies and outline the pharmacological mechanisms by which natural products modulate MQC to exert antidepressant effects. Additionally, it evaluated current research limitations and proposed new strategies for future preclinical and clinical applications in the depression domain.

METHODS

To study the main pharmacological mechanisms underlying the regulation of MQC by natural products in the treatment of depression, we conducted a thorough search across databases such as PubMed, Web of Science, and ScienceDirect databases to classify and summarize the relationship between MQC and depression, as well as the regulatory mechanisms of natural products.

RESULTS

Numerous studies have shown that irregularities in the MQC system play an important role in the pathology of depression, and the regulation of the MQC system is involved in antidepressant treatments. Natural products mainly regulate the MQC system to induce antidepressant effects by alleviating oxidative stress, balancing ATP levels, promoting mitophagy, maintaining calcium homeostasis, optimizing mitochondrial dynamics, regulating mitochondrial membrane potential, and enhancing mitochondrial biogenesis.

CONCLUSIONS

We comprehensively summarized the regulation of natural products on the MQC system in antidepressants, providing a unique perspective for the application of natural products within antidepressant therapy. However, extensive efforts are imperative in clinical and preclinical investigations to delve deeper into the mechanisms underlying how antidepressant medications impact MQC, which is crucial for the development of effective antidepressant treatments.

Palmatine attenuates LPS-induced neuroinflammation through the PI3K/Akt/NF-κB pathway

To investigate the key molecular mechanisms of palmatine for the treatment of neuroinflammation through modulation of a pathway using molecular docking, molecular dynamics (MD) simulation combined with network pharmacology, and animal experiments. Five alkaloid components were obtained from the traditional Chinese medicine Huangteng through literature mining. Molecular docking and MD simulation with acetylcholinesterase were used to screen palmatine. At the animal level, mice were injected with LPS intracerebrally to cause a neuroinflammatory model, and the Morris water maze experiment was performed to examine the learning memory of mice. Anxiety levels were tested using the autonomous activity behavior experiment with the open field and elevated behavior experiments. HE staining and Niss staining were performed on brain tissue sections to observe morphological lesions and apoptosis; serum was examined for inflammatory factors TNF-α, IL-6, and IL-1β; Western blot was performed to detect the protein expression. The expression of PI3K/AKT/NFkB signaling pathway-related proteins was examined by Western blot. The results of network pharmacology showed that the screening of palmatine activation containing the PI3K/Akt/NFkB signaling pathway exerts antineuroinflammatory effects. Results from behavioral experiments showed that Pal enhanced learning memory in model mice, improved anxiety behavior, and significantly improved brain damage caused by neuroinflammation. The results of HE staining and Niss staining of brain tissue sections showed that palmatine could alleviate morphological lesions and nucleus damage in brain tissue. Palmatine improved the levels of serum inflammatory factors TNF-α, IL-6, and IL-1β. SOD, MDA, CAT, ACH, and ACHE in the hippocampus were improved. Western blot results showed that palmatine administration ameliorated LPS-induced neuroinflammation through the PI3K/Akt/NFkB pathway.

Berberine exerts antidepressant effects in vivo and in vitro through the PI3K/AKT/CREB/BDNF signaling pathway

BACKGROUND

Depression, a global neuropsychiatric disorder, brings a serious burden to patients and society as its incidence continues to rise. Berberine is one of the main compounds of a variety of Chinese herbal medicines and has been shown to have multiple pharmacological effects. However, whether berberine can exert antidepressant effects in vivo and in vitro and its related mechanisms remain to be explored.

METHODS

The chronic restraint stress (CRS) method and corticosterone (CORT) were applied to simulate depression-like behavior in vivo and neuronal apoptosis in vitro, respectively. The antidepressant effects of berberine were evaluated by behavioral tests and changes in the content of monoamine neurotransmitters. Inflammatory cytokines were detected and immunofluorescence staining was used to observe the expression levels of apoptosis-related proteins. RT-qPCR and Western blot were used to examine the mRNA and protein expression (or phosphorylation) levels of biomarkers of the PI3K/AKT/CREB/BDNF signaling pathways.

RESULTS

Behavioral tests and levels of neurotransmitters proved that berberine could effectively ameliorate depression-like symptoms in CRS mice. Meanwhile, the results of ELISA and immunofluorescence staining showed that berberine could alleviate inflammatory status and reduce cell apoptosis in vivo and in vitro. Moreover, the changes of the PI3K/AKT/CREB/BDNF signaling pathway induced by CRS or CORT in mouse hippocampus or HT-22 cells were significantly reversed by berberine.

CONCLUSION

Our current study suggested that berberine could exert antidepressant effects in vitro and in vivo, which may be associated with the PI3K/AKT/CREB/BDNF signaling pathway.