Matrine alleviates spatial learning and memory impairment in diabetic mice by inhibiting endoplasmic reticulum stress and through modulation of PK2/PKRs pathway

Bitter yet beneficial: The dual role of dietary alkaloids in managing diabetes and enhancing cognitive function

With the rising prevalence of diabetes and its association with cognitive impairment, interest in the use of dietary alkaloids and other natural products has grown significantly. Understanding how these compounds manage diabetic cognitive dysfunction (DCD) is crucial. This comprehensive review explores the etiology of DCD and the effects of alkaloids in foods and dietary supplements that have been investigated as DCD therapies. Data on how dietary alkaloids like berberine, trigonelline, caffeine, capsaicin, 1-deoxynojirimycin, nuciferine, neferine, aegeline, tetramethylpyrazine, piperine, and others regulate cognition in diabetic disorders were collected from PubMed, Research Gate, Web of Science, Science Direct, and other relevant databases. Dietary alkaloids could improve memory in behavioral models and modulate the mechanisms underlying the cognitive benefits of these compounds, including their effects on glucose metabolism, gut microbiota, vasculopathy, neuroinflammation, and oxidative stress. Evidence suggests that dietary alkaloids hold promise for improving cognition in diabetic patients and could open exciting avenues for future research in diabetes management.

Therapeutic Potential of Targeting Prokineticin Receptors in Diseases

The prokineticins (PKs) were discovered approximately 20 years ago as small peptides inducing gut contractility. Today, they are established as angiogenic, anorectic, and proinflammatory cytokines, chemokines, hormones, and neuropeptides involved in variety of physiologic and pathophysiological pathways. Their altered expression or mutations implicated in several diseases make them a potential biomarker. Their G-protein coupled receptors, PKR1 and PKR2, have divergent roles that can be therapeutic target for treatment of cardiovascular, metabolic, and neural diseases as well as pain and cancer. This article reviews and summarizes our current knowledge of PK family functions from development of heart and brain to regulation of homeostasis in health and diseases. Finally, the review summarizes the established roles of the endogenous peptides, synthetic peptides and the selective ligands of PKR1 and PKR2, and nonpeptide orthostatic and allosteric modulator of the receptors in preclinical disease models. The present review emphasizes the ambiguous aspects and gaps in our knowledge of functions of PKR ligands and elucidates future perspectives for PK research. SIGNIFICANCE STATEMENT: This review provides an in-depth view of the prokineticin family and PK receptors that can be active without their endogenous ligand and exhibits "constitutive" activity in diseases. Their non- peptide ligands display promising effects in several preclinical disease models. PKs can be the diagnostic biomarker of several diseases. A thorough understanding of the role of prokineticin family and their receptor types in health and diseases is critical to develop novel therapeutic strategies with safety concerns.

MAT as a promising therapeutic strategy against triple-negative breast cancer via inhibiting PI3K/AKT pathway

Triple-negative breast cancer (TNBC), a highly aggressive and heterogeneous subtype of breast cancer, lacks effective treatment options. Sophora flavescens Aiton, a Chinese medicinal plant, is often used in traditional Chinese medicine to treat cancer. Matrine (MAT) is an alkaloid extracted from Sophora flavescens. It has good anticancer effects, and thus can be explored as a new therapeutic agent in TNBC research. We performed bioinformatics analysis to analyze the differentially expressed genes between normal breast tissues and TNBC tissues, and comprehensive network pharmacology analyses. The activity and invasion ability of TNBC cells treated with MAT were analyzed. Apoptosis and cell cycle progression were determined using cytometry. We used Monodansylcadaverine (MDC) staining to determine the condition of autophagosomes. Finally, the expression levels of the key target proteins of the PI3K/AKT pathway were determined using western blotting. The proliferation and invasion ability of MDA-MB-231 and MDA-MB-468 can be effectively inhibited by MAT. The results of flow cytometry indicated that MAT arrested the TNBC cell cycle and induced apoptosis. In addition, we confirmed that MAT inhibited the expression of BCL-2 while up-regulating the expression of cleaved caspase-3. Moreover, enhanced intensity of MDC staining and high LC3-II expression were observed, which confirmed that MAT induced autophagy in TNBC cells. Western blotting showed that MAT inhibited the PI3K/AKT pathway and downregulated the expressions of PI3K, AKT, p-AKT, and PGK1. This study provides feasible methods, which include bioinformatics analysis and in vitro experiments, for the identification of compounds with anti-TNBC properties. MAT inhibited the PI3K/AKT signaling pathway, arrested cell cycle, as well as promoted cell apoptosis and autophagy. These experiments provide evidence for the anti-TNBC effect of MAT and identified potential targets against TNBC.

Roles of prokineticin 2 in electroconvulsive shock-induced memory impairment via regulation of phenotype polarization in astrocytes

Electroconvulsive shock (ECT) is the most effective treatment for depression but can impair learning and memory. ECT is increasingly being shown to activate astrocytes and induce neuroinflammation, resulting in cognitive decline. Activated astrocytes can differentiate into two subtypes, A1-type astrocytes and A2-type astrocytes. Regarding cognitive function, neurotoxic A1 astrocytes and neuroprotective A2 astrocytes may exhibit opposite effects. Specifically, prokineticin 2 (PK2) functions as an essential mediator of inflammation and induces a selective A2-protective phenotype in astrocytes. This study aimed to clarify how PK2 promotes improved learning memory following electroconvulsive shock (ECS). As part of the study, rats were modeled using chronic unpredictable mild stress. Behavioral experiments were conducted to assess their cognitive abilities and depression-like behaviors. Western blot was used to determine the expression of PK2. Immunohistochemical and electron microscopy analyses of the hippocampal CA1 region were conducted to study the activation of astrocyte subtypes and synaptic ultrastructure, respectively. In this study, rats' spatial learning and memory impairment began to improve as activated A1-subtype astrocytes gradually decreased, and PK2 and A2 phenotype activation peaked on the third day after ECS. PKRA7 (PK2 antagonist) inhibits A2-type astrocyte activation partially and suppresses spatial learning and memory improvement. Collectively, our findings support that PK2 may induce a selective modulation of astrocytic polarization to a protective phenotype to promote learning and memory improvement after ECS.

PTP1B Inhibitor Claramine Rescues Diabetes-Induced Spatial Learning and Memory Impairment in Mice

Accumulating clinical and epidemiological studies indicate that learning and memory impairment is more prevalent among people with diabetes mellitus (DM). PTP1B is a member of protein tyrosine phosphatase family and participates in a variety of pathophysiological effects including inflammatory, insulin signaling pathway, and learning and memory. This study was aimed to investigate the effects of CA, a specific inhibitor of PTP1B, on spatial learning and memory impairment in diabetic mice caused by high-fat diet and injection of streptozotocin. We found that the protein expressions of PTP1B increased in hippocampal CA1, CA3, and PFC regions of diabetic mice. Network pharmacology results showed that PTP1B might be one of the key targets between diabetes and cognitive dysfunction, and CA might alleviate DM-induced cognitive dysfunction. Animal experiments showed that CA ameliorated DM-induced spatial learning and memory impairment, and improved glucose and lipid metabolic disorders. Moreover, administration of CA alleviated hippocampal structure damage and enhanced the expressions of synaptic proteins, including PSD-95, SYN-1, and SYP in diabetic mice. Furthermore, CA treatment not only significantly down-regulated the expressions of PTP1B and NLRP3 inflammatory related proteins (NLRP3, ASC, Caspase-1, COX-2, IL-1β, and TNF-α), but also significantly up-regulated the expressions of insulin signaling pathway-related proteins (p-IRS1, p-PI3K, p-AKT, and p-GSK-3β) in diabetic mice. Taken together, these results suggested that PTP1B might be a targeted strategy to rescue learning and memory deficits in DM, possibly through inhibition of NLRP3 inflammasome and regulation of insulin signaling pathway.

Role of potential bioactive metabolites from traditional Chinese medicine for type 2 diabetes mellitus: An overview

Type 2 diabetes mellitus (T2DM) is a metabolic disease with persistent hyperglycemia primarily caused by insulin resistance (IR). The number of diabetic patients globally has been rising over the past decades. Although significant progress has been made in treating diabetes mellitus (DM), existing clinical drugs for diabetes can no longer fully meet patients when they face complex and huge clinical treatment needs. As a traditional and effective medical system, traditional Chinese medicine (TCM) has a unique understanding of diabetes treatment and has developed many classic and practical prescriptions targeting DM. With modern medicine and pharmacy advancements, researchers have discovered that various bioactive metabolites isolated from TCM show therapeutic on DM. Compared with existing clinical drugs, these bioactive metabolites demonstrate promising prospects for treating DM due to their excellent biocompatibility and fewer adverse reactions. Accordingly, these valuable metabolites have attracted the interest of researchers worldwide. Despite the abundance of research works and specialized-topic reviews published over the past years, there is a lack of updated and systematic reviews concerning this fast-growing field. Therefore, in this review, we summarized the bioactive metabolites derived from TCM with the potential treatment of T2DM by searching several authoritative databases such as PubMed, Web of Science, Wiley Online Library, and Springer Link. For the convenience of readers, the content is divided into four parts according to the structural characteristics of these valuable compounds (flavonoids, terpenoids, alkaloids, and others). Meanwhile, the detailed mechanism and future directions of these promising compounds curing DM are also summarized in the related sections. We hope this review inspires increasingly valuable and significant research focusing on potential bioactive metabolites from TCM to treat DM in the future.

Research progress on the pharmacological effects of matrine

Matrine possesses anti-cancer properties, as well as the prevention and treatment of allergic asthma, and protection against cerebral ischemia-reperfusion injury. Its mechanism of action may be (1) regulation of cancer cell invasion, migration, proliferation, and cell cycle to inhibit tumor growth; (2) reduction of oxidized low-density lipoprotein and advanced glycation end products from the source by exerting anti-inflammatory and antioxidant effects; (3) protection of brain damage and cortical neurons by regulating apoptosis; (4) restoration of the intestinal barrier and regulation of the intestinal microbiota. This article aims to explore matrine’s therapeutic potential by summarizing comprehensive information on matrine’s pharmacology, toxicity, and bioavailability.