Effects of berberine on cholinesterases and monoamine oxidase activities, and antioxidant status in the brain of streptozotocin (STZ)-induced diabetic rats

Berberine Hydrochloride Improves Cognitive Function and Hippocampal Antioxidant Status in Subchronic and Chronic Lead Poisoning

OBJECTIVES

To determine the neuroprotective effects of berberine hydrochloride (BBR) against lead-induced injuries on the hippocampus of rats.

METHODS

Wistar rats were exposed orally to doses of 100 and 500 ppm lead acetate for 1 and 2 months to develop subchronic and chronic lead poisening models, respectively. For treatment, BBR (50 mg/kg daily) was injected intraperitoneally to rats poisoned with lead. At the end of the experiment, the spatial learning and memory of rats were assessed using the Morris water maze test. Hippocampal tissue changes were examined by hematoxylin and eosin staining. The activity of antioxidant enzymes catalase, superoxide dismutase, glutathione peroxidase, and malondialdehyde levels as parameters of oxidative stress and antioxidant status of the hippocampus were evaluated.

RESULTS

BBR reduced cognitive impairment in rats exposed to lead (P<0.05 or P<0.01). The resulting biochemical changes included a decrease in the activity of antioxidants and an increase in lipid peroxidation of the hippocampus of lead-exposed rats (P<0.05 or P<0.01), which were significantly modified by BBR (P<0.05). BBR also increased the density of healthy cells in the hippocampus of leadexposed rats (P<0.05). Significant changes in tissue morphology and biochemical factors of the hippocampus were observed in rats that received lead for 2 months (P<0.05). Most of these changes were insignificant in rats that received lead for 1 month.

CONCLUSION

BBR can improve oxidative tissue changes and hippocampal dysfunction in lead-exposed rats, which may be due to the strong antioxidant potential of BBR.

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.

Brain-targeted Tet-1 peptide-PLGA nanoparticles for berberine delivery against STZ-induced Alzheimer's disease in a rat model: Alleviation of hippocampal synaptic dysfunction, Tau pathology, and amyloidogenesis

Alzheimer's disease (AD) is an age-related neurodegenerative disorder that causes severe dementia and memory loss. Surface functionalized poly(lactic-co-glycolic acid) nanoparticles have been reported for better transport through the blood-brain barrier for AD therapy. This study investigated the improved therapeutic potential of berberine-loaded poly(lactic-co-glycolic acid)/Tet-1 peptide nanoparticles (BBR/PLGA-Tet NPs) in a rat model of sporadic AD. BBR was loaded into the PLGA-Tet conjugate. BBR/PLGA-Tet NPs were physicochemically and morphologically characterized. AD was achieved by bilateral intracerebroventricular (ICV) injection of streptozotocin (STZ). Cognitively impaired rats were divided into STZ, STZ + BBR, STZ + BBR/PLGA-Tet NPs, and STZ + PLGA-Tet NPs groups. Cognitive improvement was assessed using the Morris Water Maze. Brain acetylcholinesterase and monoamine oxidase activities, amyloid β42 (Aβ42), and brain glycemic markers were estimated. Further, hippocampal neuroplasticity (BDNF, pCREB, and pERK/ERK), Tau pathogenesis (pGSK3β/GSK3β, Cdk5, and pTau), inflammatory, and apoptotic markers were evaluated. Finally, histopathological changes were monitored. ICV-STZ injection produces AD-like pathologies evidenced by Aβ42 deposition, Tau hyperphosphorylation, impaired insulin signaling and neuroplasticity, and neuroinflammation. BBR and BBR/PLGA-Tet NPs attenuated STZ-induced hippocampal damage, enhanced cognitive performance, and reduced Aβ42, Tau phosphorylation, and proinflammatory responses. BBR/PLGA-Tet NPs restored neuroplasticity, cholinergic, and monoaminergic function, which are critical for cognition and brain function. BBR/PLGA-Tet NPs may have superior therapeutic potential in alleviating sporadic AD than free BBR due to their bioavailability, absorption, and brain uptake.

A Mechanistic Review on How Berberine Use Combats Diabetes and Related Complications: Molecular, Cellular, and Metabolic Effects

Berberine (BBR) is an isoquinoline alkaloid that can be extracted from herbs such as Coptis, Phellodendron, and Berberis. BBR has been widely used as a folk medicine to treat various disorders. It is a multi-target drug with multiple mechanisms. Studies have shown that it has antioxidant and anti-inflammatory properties and can also adjust intestinal microbial flora. This review focused on the promising antidiabetic effects of BBR in several cellular, animal, and clinical studies. Based on previous research, BBR significantly reduced levels of fasting blood glucose, hemoglobin A1C, inflammatory cytokines, and oxidative stress markers. Furthermore, BBR stimulated insulin secretion and improved insulin resistance through different pathways, including up-regulation of protein expression of proliferator-activated receptor (PPAR)-γ, glucose transporter (GLUT) 4, PI3K/AKT, and AMP-activated protein kinase (AMPK) activation. Interestingly, it was demonstrated that BBR has protective effects against diabetes complications, such as diabetic-induced hepatic damage, cardiovascular disorders, nephropathy, and neuropathy. Furthermore, multiple clinical trial studies have emphasized the ameliorative effects of BBR in type 2 diabetic patients.

Pomegranate polyphenol punicalagin improves learning memory deficits, redox homeostasis, and neuroinflammation in aging mice

Alzheimer's disease (AD) is an irreversible, progressive brain disorder characterized by loss of memory and cognitive dysfunction in the aged. Despite remarkable advances in drug therapy, effective pharmacological interventions are rare. Punicalagin (PU) is an active antioxidant polyphenol found in pomegranates, raspberries, blueberries, and chestnuts that has attracted considerable attention owing to its strong antioxidant and anti-inflammatory properties. The current study focused on the neuroprotective effect of PU on aging mice and its potential mechanisms. In this study, we first evaluated the protective effect of PU on neuro-2a (N2a) cell damage mediated by BV2 microglia-induced neuroinflammation. The in vivo D-galactose (D-gal)-induced brain aging model demonstrated that PU ameliorated deficits in learning and memory and prevented neuroinflammation, which was evident from the decrease in microglial activation and astrocytosis. Furthermore, PU reduced the levels of malondialdehyde (MDA) and reactive oxygen species (ROS) and inhibited NLRP3 inflammasome activation, reducing the levels of inflammatory cytokines, such as interleukin-6 (IL-6), tumor necrosis factor-a (TNF-a), interleukin-18 (IL-18), and interleukin-1 beta (IL-1β) in both accelerated aging and naturally senescent mouse models. PU effectively improved neuroinflammation, learning and memory deficits, and redox homeostasis in aging mice, and it could be a potential therapeutic agent for AD.

A Review of Fibraurea tinctoria and Its Component, Berberine, as an Antidiabetic and Antioxidant

Diabetes mellitus is a group of metabolic disorders characterized by hyperglycemia caused by resistance to insulin action, inadequate insulin secretion, or excessive glucagon production. Numerous studies have linked diabetes mellitus and oxidative stress. People with diabetes usually exhibit high oxidative stress due to persistent and chronic hyperglycemia, which impairs the activity of the antioxidant defense system and promotes the formation of free radicals. Recently, several studies have focused on exploring natural antioxidants to improve diabetes mellitus. Fibraurea tinctoria has long been known as the native Borneo used in traditional medicine to treat diabetes. Taxonomically, this plant is part of the Menispermaceae family, widely known for producing various alkaloids. Among them are protoberberine alkaloids such as berberine. Berberine is an isoquinoline alkaloid with many pharmacological activities. Berberine is receiving considerable interest because of its antidiabetic and antioxidant activities, which are based on many biochemical pathways. Therefore, this review explores the pharmacological effects of Fibraurea tinctoria and its active constituent, berberine, against oxidative stress and diabetes, emphasizing its mechanistic aspects. This review also summarizes the pharmacokinetics and toxicity of berberine and in silico studies of berberine in several diseases and its protein targets.

Neuroprotective Effect and Possible Mechanisms of Berberine in Diabetes-Related Cognitive Impairment: A Systematic Review and Meta-Analysis of Animal Studies

Berberine, the main bioactive component of Coptis chinensis Franch., is widely used in the treatment of diabetes. Previous studies have reported that berberine supplementation may play a multitarget therapeutic role in diabetes-related cognitive impairment (DCI). This systematic review and meta-analysis evaluated the effect and possible mechanisms of berberine in animal models of DCI. Relevant studies were searched through PubMed, Web of Science, Embase, and three Chinese databases (CNKI, Wanfang, and VIP) until March 2022. Twenty studies involving 442 animals were included, and SYRCLE’s risk of bias tool was used to assess methodological quality. The statistical analysis was performed using STATA 15.0 to calculate the weighted standard mean difference (SMD) with a 95% confidence interval (CI). The fasting blood glucose (FBG) and Morris water maze test (MWM) were the main outcomes to be analyzed. The overall results showed that berberine could significantly improve FBG, escape latency, the times of crossing the platform, the time spent in the target quadrant, serum insulin, 2hBG of oral glucose tolerance test (OGTT), amyloid β (Aβ), acetylcholinesterase (AChE), oxidative stress, and inflammation levels. The present meta-analysis demonstrated that berberine could not only lower blood glucose levels but also improve learning and memory in DCI animal models, which might involve regulating glucose and lipid metabolism, improving insulin resistance, anti-oxidation, anti-neuroinflammation, inhibiting endoplasmic reticulum (ER) stress; and improving the cholinergic system. However, additional attention should be paid to these outcomes due to the significant heterogeneity.