Berberine Ameliorates Glucose Metabolism in Diabetic Rats through the alpha7 Nicotinic Acetylcholine Receptor-Related Cholinergic Anti-Inflammatory Pathway

Metabolic disorders in prediabetes: From mechanisms to therapeutic management

Diabetes, one of the world's top ten diseases, is known for its high mortality and complication rates and low cure rate. Prediabetes precedes the onset of diabetes, during which effective treatment can reduce diabetes risk. Prediabetes risk factors include high-calorie and high-fat diets, sedentary lifestyles, and stress. Consequences may include considerable damage to vital organs, including the retina, liver, and kidneys. Interventions for treating prediabetes include a healthy lifestyle diet and pharmacological treatments. However, while these options are effective in the short term, they may fail due to the difficulty of long-term implementation. Medications may also be used to treat prediabetes. This review examines prediabetic treatments, particularly metformin, glucagon-like peptide-1 receptor agonists, sodium glucose cotransporter 2 inhibitors, vitamin D, and herbal medicines. Given the remarkable impact of prediabetes on the progression of diabetes mellitus, it is crucial to intervene promptly and effectively to regulate prediabetes. However, the current body of research on prediabetes is limited, and there is considerable confusion surrounding clinically relevant medications. This paper aims to provide a comprehensive summary of the pathogenesis of pre-diabetes mellitus and its associated therapeutic drugs. The ultimate goal is to facilitate the clinical utilization of medications and achieve efficient and timely control of diabetes mellitus.

Elucidating the mechanisms of formononetin in modulating atherosclerotic plaque formation in ApoE-/- mice

BACKGROUND

Atherosclerosis(AS) poses a pressing challenge in contemporary medicine. Formononetin (FMN) plays a crucial role in its prevention and treatment. However, the detailed impact of FMN on the stability of atherosclerotic plaques and its underlying mechanisms remain to be elucidated.

METHODS

An intervention consisting of FMN was given along with a high-fat food regimen in the ApoE-/- mouse model. The investigation included the evaluation of the degree of atherosclerotic lesion, the main components of the plaque, lipid profiles, particular markers indicating M1/M2 macrophage phenotypes, the quantities of factors related to inflammation, the infiltration of macrophages, and the identification of markers linked to the α7nAChR/JAK2/STAT3 axis effect molecules.

RESULTS

The evaluation of aortic morphology in ApoE-/-mice revealed that FMN significantly improved the plaque area, fibrous cap protrusion, lipid deposition, and structural alterations on the aortic surface, among other markers of atherosclerosis,and there is concentration dependence. Furthermore, the lipid content of mouse serum was assessed, and the results showed that the low-, medium-, and high-dosage FMN groups had significantly lower levels of LDL-C, ox-LDL, TC, and TG. The results of immunohistochemical staining indicated that the low-, medium-, and high-dose FMN therapy groups had enhanced CD206 expression and decreased expression of CD68 and iNOS. According to RT-qPCR data, FMN intervention has the potential to suppress the expression of iNOS, COX-2, miR-155-5p, IL-6, and IL-1β mRNA, while promoting the expression of IL-10, SHIP1, and Arg-1 mRNA levels. However, the degree of inhibition varied among dosage groups. Western blot investigation of JAK/STAT signaling pathway proteins and cholinergic α7nAChR protein showed that p-JAK2 and p-STAT3 protein expression was suppressed at all dosages, whereas α7nAChR protein expression was enhanced.

CONCLUSIONS

According to the aforementioned findings, FMN can reduce inflammation and atherosclerosis by influencing macrophage polarization, blocking the JAK/STAT signaling pathway, and increasing α7nAChR expression.

Berberine attenuates cognitive dysfunction and hippocampal apoptosis in rats with prediabetes

The cognitive dysfunction caused by prediabetes causes great difficulties in human life, and the terrible thing is that the means to prevent the occurrence of this disease are very limited at present, Berberine has shown the potential to treat diabetes and cognitive dysfunction, but it still needs to be further explored to clarify the mechanism of its therapeutic effect. Therefore, the aim of this study was to investigate the effects and mechanisms of Berberine on prediabetes-induced cognitive dysfunction. Prediabetes rat model was induced by a high-fat diet and a normal diet was used as a control. They were fed for 20 weeks. At week 13, the model rats were given 100 mg/kg Berberine by gavage for 7 weeks. The cognitive function of rats was observed. At the same time, OGTT, fasting blood glucose, blood lipids, insulin and other metabolic parameters, oxidative stress, and apoptosis levels were measured. The results showed that the model rats showed obvious glucose intolerance, elevated blood lipids, and insulin resistance, and the levels of oxidative stress and apoptosis were significantly increased. However, after the administration of Berberine, the blood glucose and lipid metabolism of prediabetic rats were significantly improved, and the oxidative stress level and apoptosis level of hippocampal tissue were significantly reduced. In conclusion, Berberine can alleviate the further development of diabetes in prediabetic rats, reduce oxidative stress and apoptosis in hippocampal tissue, and improve cognitive impairment in prediabetic rats.

Role of Fenugreek, Cinnamon, Curcuma longa, Berberine and Momordica charantia in Type 2 Diabetes Mellitus Treatment: A Review

Type 2 diabetes mellitus (T2DM) is a complex disease that has become a major global health concern. Given the efficacy of antidiabetic drugs, pharmacological therapy is considered the first-line treatment of T2DM; however, due to their potential side effects and high costs, new and cost-effective treatments with minimal side effects are needed. Medicinal plants have been used for centuries as part of traditional medicine to treat T2DM. Among these, fenugreek, cinnamon, Curcuma longa, berberine, and Momordica charantia have demonstrated different degrees of hypoglycemic activity in clinical studies and animal models. Therefore, the aim of this review is to synthesize the mechanisms of action of five medicinal plants, as well as the experimental and clinical evidence of their hypoglycemic activity from the published literature.

A High Dose of Dietary Berberine Improves Gut Wall Morphology, Despite an Expansion of Enterobacteriaceae and a Reduction in Beneficial Microbiota in Broiler Chickens

Phytogenic products are embraced as alternatives to antimicrobials, and some are known to mitigate intestinal inflammation and ensure optimal gut health and performance in broiler chickens. Dietary inclusion of berberine, a benzylisoquinoline alkaloid found in plants, is believed to exert gut health-promoting effects through modulation of the gut microbiota; however, there are only a few studies investigating its effects in chickens. The aim of this study was to investigate the interplay between dietary supplementation of a high concentration of berberine, the gastrointestinal microbiota, and histomorphological parameters in the gut. Berberine was shown to increase villus length and decrease crypt depth and CD3⁺ T-lymphocyte infiltration in the gut tissue of chickens at different ages. Berberine affected the diversity of the gut microbiota from the jejunum to the colon, both at a compositional and functional level, with larger effects observed in the large intestine. A high concentration of berberine enriched members of the Enterobacteriaceae family and depleted members of the Ruminococcaceae, Lachnospiraceae, and Peptostreptococcaceae families, as well as tended to reduce butyrate production in the cecum. In vivo results were confirmed by in vitro growth experiments, where increasing concentrations of berberine inhibited the growth of several butyrate-producing strains while not affecting that of Enterobacteriaceae strains. Positive correlations were found between berberine levels in plasma and villus length or villus-to-crypt ratio in the jejunum. Our study showed that berberine supplementation at a high concentration improves chicken gut morphology toward decreased inflammation, which is likely not mediated by the induced gut microbiota shifts. IMPORTANCE Dietary additives are widely used to reduce intestinal inflammation and enteritis, a growing problem in the broiler industry. Berberine, with anti-inflammatory, antioxidant, and antimicrobial activity, would be an interesting feed additive in this regard. This study investigates for the first time the impact of berberine supplementation on the chicken gastrointestinal microbiota, as a potential mechanism to improve gut health, together with histological effects in the small intestine. This study identified a dose-effect of berberine on the gut microbiota, indicating the importance of finding an optimal dose to be used as a dietary additive.

α7 nicotinic acetylcholine receptor agonist improved brain injury and impaired glucose metabolism in a rat model of ischemic stroke

Vagus nerve stimulation through the action of acetylcholine can modulate inflammatory responses and metabolism. α7 Nicotinic Acetylcholine Receptor (α7nAChR) is a key component in the biological functions of acetylcholine. To further explore the health benefits of vagus nerve stimulation, this study aimed to investigate whether α7nAChR agonists offer beneficial effects against poststroke inflammatory and metabolic changes and to identify the underlying mechanisms in a rat model of stroke established by permanent cerebral ischemia. We found evidence showing that pretreatment with α7nAChR agonist, GTS-21, improved poststroke brain infarction size, impaired motor coordination, brain apoptotic caspase 3 activation, dysregulated glucose metabolism, and glutathione reduction. In ischemic cortical tissues and gastrocnemius muscles with GTS-21 pretreatment, macrophages/microglia M1 polarization-associated Tumor Necrosis Factor-α (TNF-α) mRNA, Cluster of Differentiation 68 (CD68) protein, and Inducible Nitric Oxide Synthase (iNOS) protein expression were reduced, while expression of anti-inflammatory cytokine IL-4 mRNA, and levels of M2 polarization-associated CD163 mRNA and protein were increased. In the gastrocnemius muscles, stroke rats showed a reduction in both glutathione content and Akt Serine 473 phosphorylation, as well as an elevation in Insulin Receptor Substrate-1 Serine 307 phosphorylation and Dynamin-Related Protein 1 Serine 616 phosphorylation. GTS-21 reversed poststroke changes in the gastrocnemius muscles. Overall, our findings, provide further evidence supporting the neuroprotective benefits of α7nAChR agonists, and indicate that they may potentially exert anti-inflammatory and metabolic effects peripherally in the skeletal muscle in an acute ischemic stroke animal model.

Berberine Improves TNF-α-Induced Hepatic Insulin Resistance by Targeting MEKK1/MEK Pathway

Berberine (BBR), a natural isoquinoline alkaloid exhibiting insulin sensitizing activity, has been applicated in the treatment of diabetes. However, until now, the exact target of BBR has not been well investigated. Here, primary hepatocytes pre-treated with TNF-α were used to evaluate the role of BBR on hepatic insulin sensitivity. Western blot and immunoprecipitation were used to investigate the effect of BBR on the crosstalk between TNF-α pathway and insulin signaling pathway. Molecular docking was used to verify the interactions between BBR and its potential targets. BBR inhibits the MEKK1 and MEK1/2, and thus suppresses the activation of their downstream ERK1/2. It attenuates the ERK1/2-induced serine phosphorylation of IRS-1 and thus enhances IRS-1 tyrosine phosphorylation and Akt activation. By molecular docking, BBR is proved to efficiently bind MEK1/2. MEKK1 is also considered as BBR target for its similarity in primary structure with MEK1/2. In conclusion, BBR ameliorates TNF-α-induced hepatic insulin resistance by targeting MEKK1 and MEK1/2.