Berberine inhibits SGIV replication by suppressing inflammatory response and oxidative stress

Singapore grouper iridovirus (SGIV) is one of the major infectious diseases responsible for high mortality and huge economic losses in the grouper aquaculture industry. Berberine (BBR), a naturally occurring plant alkaloid, is a phytochemical having a variety of biological properties, such as antiviral, antioxidant, and anti-inflammatory effects. In this work, we used an in vitro model based on Western blot, ROS fluorescence probe, and real-time quantitative PCR (qRT-PCR) to examine the antiviral qualities of BBR against SGIV. The outcomes demonstrated that varying BBR concentrations could significantly inhibit the replication of SGIV. In addition, BBR greatly inhibited the production of genes associated with pro-inflammatory cytokines in SGIV-infected or SGIV-uninfected GS cells based on qRT-PCR data. Subsequent investigations demonstrated that BBR suppressed the expression of the promoter activity of NF-κB and NF-κB-p65 protein. Additionally, BBR reduced the phosphorylation of ERK 1/2, JNK, and p38. Furthermore, BBR also inhibits SGIV-induced ROS production by upregulating the expression of antioxidant-related genes. In conclusion, BBR is a viable therapy option for SGIV infection due to its antiviral properties.

Phytol from Scoparia dulcis prevents NF-κB-mediated inflammatory responses during macrophage polarization

Macrophages are primary immune cells that mediate a wide range of inflammatory diseases through their polarization potential. In this study, phytol isolated from Scoparia dulcis has been explored against 7-ketocholesterol and bacterial lipopolysaccharide-induced macrophage polarization in IC-21 cells. Isolated phytol has been characterized using GC-MS, TLC, HPTLC, FTIR, 1H-NMR, and HPLC analyses. The immunomodulatory effects of viable concentrations of phytol were tested on oxidative stress, arginase activity, nuclear and mitochondrial membrane potentials in IC-21 cells in addition to the modulation of calcium and lipids. Further, gene and protein expression of atherogenic markers were studied. Results showed that the isolated phytol at a viable concentration of 400 µg/ml effectively reduced the production of nitric oxide, superoxide anion (ROS generation), calcium and lipid accumulation, stabilized nuclear and mitochondrial membranes, and increased arginase activity. The atherogenic markers including iNOS, COX-2, IL-6, IL-1β, MMP-9, CD36, and NF-κB were significantly downregulated at the levels of gene and protein expression, while macrophage surface and nuclear receptor markers (CD206, CD163, and PPAR-γ) were significantly upregulated by phytol pre-treatment in macrophages. Therefore, the present pharmacognostic study supports the role of phytol isolated from Scoparia dulcis in preventing M2-M1 macrophage polarization under inflammatory conditions, making it a promising compound.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-03924-9.

Neuroprotective Properties of Berberine: Molecular Mechanisms and Clinical Implications

Berberine (BBR), an isoquinoline alkaloid natural product, is isolated primarily from Coptis chinensis and other Berberis plants. BBR possesses various bioactivities, including antioxidant, anti-inflammation, anticancer, immune-regulation, and antimicrobial activities. Growing scientific evidence underscores BBR's substantial neuroprotective potential, prompting increased interest and scrutiny. In this comprehensive review, we elucidate the neuroprotective attributes of BBR, delineate the underlying molecular mechanisms, and assess its clinical safety and efficacy. The multifaceted molecular mechanisms responsible for BBR's neuroprotection encompass the attenuation of oxidative stress, mitigation of inflammatory responses, inhibition of apoptotic pathways, facilitation of autophagic processes, and modulation of CYP450 enzyme activities, neurotransmitter levels, and gut microbiota composition. Furthermore, BBR engages numerous signaling pathways, including the PI3K/Akt, NF-κB, AMPK, CREB, Nrf2, and MAPK pathways, to confer its neuroprotective effects. This comprehensive review aims to provide a substantial knowledge base, stimulate broader scientific discourse, and facilitate advancements in the application of BBR for neuroprotection.

Sitosterol-rich Digera muricata against 7-ketocholesterol and lipopolysaccharide-mediated atherogenic responses by modulating NF-ΚB/iNOS signalling pathway in macrophages

Digera muricata L., commonly known as Tartara, is an edible herb used as traditional medicine in many countries of Africa and Asia. This study aimed to elucidate the effect of a phytosterol-rich extract of D. muricata on 7-ketocholesterol-mediated atherosclerosis in macrophages. The extract was examined by phytochemical analyses, GC-MS, TLC, DPPH scavenging and hRBC membrane stabilization assays. Macrophage polarization was studied with experimental groups framed based on alamar blue cell viability and griess assays. Regulations of arginase enzyme activity, ROS generation, mitochondrial membrane potential, cell membrane integrity, pinocytosis, lipid uptake and peroxidation, as well as, intracellular calcium deposition were determined. In addition, expressions of atherogenic mediators were analysed using PCR, ELISA and immunocytochemistry techniques. Diverse phytochemicals with higher free radical scavenging activity and anti-inflammatory potential have been detected in the D. muricata. Co-treatment with D. muricata markedly reduced the atherogenic responses induced by 7KCh in the presence of LPS such as ROS, especially, NO and O2- along with lipid peroxidation. Furthermore, D. muricata significantly normalized mitochondrial membrane potential, cell membrane integrity, pinocytic activity, intracellular lipid accumulation and calcium deposition. These results provided us with the potentiality of D. muricata in ameliorating atherogenesis. Additionally, it decreased the expression of pro-atherogenic mediators (iNOS, COX-2, MMP9, IL-6, IL-1β, CD36, CD163 and TGFβ1) and increased anti-atherogenic mediators (MRC1 and PPARγ) with high cellular expressions of NF-κB and iNOS. Results showed the potential of sitosterol-rich D. muricata as a versatile biomedical therapeutic agent against abnormal macrophage polarization and its associated pathologies.

Oxidative stress, hormones, and effects of natural antioxidants on intestinal inflammation in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, relapsing gastrointestinal (GI) disorder characterized by intestinal inflammation. The etiology of IBD is multifactorial and results from a complex interplay between mucosal immunity, environmental factors, and host genetics. Future therapeutics for GI disorders, including IBD, that are driven by oxidative stress require a greater understanding of the cellular and molecular mechanisms mediated by reactive oxygen species (ROS). In the GI tract, oxidative stressors include infections and pro-inflammatory responses, which boost ROS generation by promoting the production of pro-inflammatory cytokines. Nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) represent two important signaling pathways in intestinal immune cells that regulate numerous physiological processes, including anti-inflammatory and antioxidant activities. Natural antioxidant compounds exhibit ROS scavenging and increase antioxidant defense capacity to inhibit pro-oxidative enzymes, which may be useful in IBD treatment. In this review, we discuss various polyphenolic substances (such as resveratrol, curcumin, quercetin, green tea flavonoids, caffeic acid phenethyl ester, luteolin, xanthohumol, genistein, alpinetin, proanthocyanidins, anthocyanins, silymarin), phenolic compounds including thymol, alkaloids such as berberine, storage polysaccharides such as tamarind xyloglucan, and other phytochemicals represented by isothiocyanate sulforaphane and food/spices (such as ginger, flaxseed oil), as well as antioxidant hormones like melatonin that target cellular signaling pathways to reduce intestinal inflammation occurring with IBD.

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.

Berberine enhances autophagic flux by activating the Nrf2 signaling pathway in bovine endometrial epithelial cells to resist LPS-induced apoptosis

Berberine exerts many beneficial effects on lipopolysaccharide (LPS)-induced bovine endometrial epithelial cells (BEECs). Recently, we also found that berberine shows significant antiapoptotic and autophagy-promoting activities, but the underlying mechanism has not been elucidated. This research explored the association between the antiapoptotic and autophagy-promoting activities of berberine in LPS-treated BEECs. BEECs were first preconditioned with an inhibitor of autophagic flux (chloroquine [CQ]) for 1 h, treated with berberine for 2 h, and then incubated with LPS for 3 h. Cell apoptosis was assessed by flow cytometry, and autophagy activities were assessed by immunoblot analysis of LC3II and p62. The results indicated that the antiapoptotic activity of berberine was notably inhibited in LPS-treated BEECs after preconditioning with CQ for 1 h. Furthermore, to determine whether berberine promoted autophagy by activating the nuclear factor-erythroid 2 related factor 2 (Nrf2) signaling pathway, we assessed autophagy in LPS-treated BEECs after preconditioning with a signaling pathway inhibitor of Nrf2 (ML385). The results indicated that the enhanced autophagy activity induced by berberine was partially reversed in LPS-treated BEECs after the Nrf2 signaling pathway was disturbed by ML385. In conclusion, berberine enhances autophagic flux to allow resistance to LPS-induced apoptosis by activating the Nrf2 signaling pathway in BEECs. The present study may provide new insight into the antiapoptotic mechanism of berberine in LPS-induced BEECs.

Potential Use of African Botanicals and Other Compounds in the Treatment of Methicillin-Resistant Staphylococcus aureus Infections

Infections caused by the group of Staphylococcus bacteria are commonly called Staph infections, and over 30 types of Staphylococcal bacteria exist with Staphylococcus aureus causing about 90% of the infections from the genus. Staphylococcus aureus (S. aureus) is a major cause of both hospital- and community-acquired infections with major concern arising from its strain of species that is resistant to many antibiotics. One of such strain is the Methicillin-resistant Staphylococcus aureus (MRSA) that has been described to be a resistance to methicillin drugs. Another is glycopeptides-resistant emerging from the increased use of glycopeptides drugs. This continuous emergence and spread of new resistant strains of S. aureus is a major challenge which makes the search for novel anti-resistant agents imperative. The development of vaccines from natural and synthetic products is some of the measures being proposed for the protection against the infections. Also, the development of monoclonal or polyclonal antibodies for passive immunization is sought for, and attentions with regard to arriving at successful trials have been directed back to medicinal plant research as an alternative. This review discusses the treatment strategies of MRSA, the antibacterial property of various medicinal plants, and the influence of their active compounds on methicillin-resistant S. aureus (MRSA), as well as to recommend the path to future research in this area.

Anti-oxidative and anti-inflammatory activities of the ethanol extract of edible flower from Chimonanthus praecox

Chimonanthi Praecocis Flos, namely wintersweet flower, is the edible flower or flower bud of Chimonanthus praecox (L.) Link which is a deciduous shrub plant originated from China and is widely cultivated as a garden or ornamental plant all over the world. However, few studies focused on its anti-inflammatory property. In the present study, we explored the anti-inflammatory and anti-oxidative activities of ethanol extract of Chimonanthi Praecocis Flos (CPE) which contained 7.980% ± 0.176% total flavonoids and 1.461% ± 0.041% total alkaloids. In LPS-stimulated RAW264.7 macrophages, CPE significantly decreased the production of NO and prostaglandin E₂ (PGE₂) through reducing the expressions of their synthases—inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). It also suppressed the transcription and translation of pro-inflammatory cytokines interleukin-1β (IL-1β) and interleukin-6 (IL-6). Further research revealed that CPE impeded the phosphorylation and degradation of IκBα, thus restraining the nuclear translocation of p65, and consequently dampening NF-κB signaling. In endotoxemia mice, several pro-inflammatory cytokines in serum were also decreased after CPE treatment. Besides anti-inflammatory activity, anti-oxidative activity is another important capacity of wintersweet flower. Indeed, CPE reduced LPS-elevated intracellular total reactive oxygen species (ROS) level by weakening NADPH oxidase activity in cell system. Moreover, it directly scavenged DPPH radical and superoxide anion, and exerted ferric reducing ability in cell-free system. Our findings demonstrate that wintersweet flower can be used as a beneficial natural product or an additive by virtue of its anti-oxidative and anti-inflammatory properties.

An insight into the potential of berberine in animal nutrition: Current knowledge and future perspectives

In animal nutrition, the interest for novel feed additives has expanded with elevating industry standards and consumer awareness besides the demand for healthy animal-derived food products. Consumer and animal health are leading concerns dictating the importance of novel animal feed additives. Berberine (BBR) is a natural pentacyclic isoquinoline alkaloid that has exhibited diverse pharmacological properties, including metabolism-regulating, hepatoprotective, and inflammatory alleviative in addition to its antioxidant activity. Despite detailed information on cellular mechanisms associated with BBR therapeutics, and strong clinical evidence, only a few studies have focused on BBR applied to animal nutrition. However, great pieces of evidence have shown that dietary BBR supplementation could result in improved growth performance, enhanced oxido-inflammatory markers, and mitigated metabolic dysfunctions in both monogastric and ruminant animals. The data discussed in the present review may set the basis for further research on BBR in animal diets for developing novel strategies aiming to improve animal health as well as products with beneficial properties for humans.

Ultrafine Diesel Exhaust Particles Induce Apoptosis of Oligodendrocytes by Increasing Intracellular Reactive Oxygen Species through NADPH Oxidase Activation

Diesel exhaust particles (DEPs) are a main contributor to air pollution. Ultrafine DEPs can cause neurodegenerative diseases by increasing intracellular reactive oxygen species (ROS). Compared with other cells in the brain, oligodendrocytes responsible for myelination are more susceptible to oxidative stress. However, the mechanisms underlying ROS generation in oligodendrocytes and the susceptibility of oligodendrocytes to ROS by ultrafine DEPs remain unclear. Herein, we examined the effects of excessive ROS generated by NOX2, an isoform of the NADPH oxidase family, after exposure to ultrafine DEPs (200 μg/mL) on the survival of two types of oligodendrocytes—oligodendrocyte precursor cells (OPCs) and mature oligodendrocytes (mOLs)––isolated from the brain of neonatal rats. In addition, mice were exposed to ultrafine DEP suspension (20 μL, 0.4 mg/mL) via the nasal route for 1 week, after which the expression of NOX2 and cleaved caspase-3 was examined in the white matter of the cerebellum. Exposure to DEPs significantly increased NOX2 expression and ROS generation in OPCs and mOLs. OPCs and mOLs clearly exhibited viability reduction, and a significant change in p53, Bax, Bcl-2, and cleaved caspase-3 expression, after DEP exposure. In contrast, treatment with berberine (BBR), an NOX2 inhibitor, significantly mitigated these effects. In mice exposed to DEP, the presence of NOX2-positive and cleaved caspase-3-positive oligodendrocytes was demonstrated in the cerebellar white matter; NOX2 and cleaved caspase-3 expression in the cerebellum lysates was significantly increased. BBR treatment returned expression of these proteins to control levels. These results demonstrate that the susceptibility of OPCs and mOLs to ultrafine DEPs is, at least in part, caused by excessive ROS produced by NOX2 and the sequential changes in the expression of p53, Bax, Bcl-2, and cleaved caspase-3. Overall, NOX2 inhibitor enhances the survival of two types of oligodendrocytes.

Berberine Is a Promising Alkaloid to Attenuate Iron Toxicity Efficiently in Iron-Overloaded Mice

Iron toxicity in iron-overloaded conditions, including high iron diet and blood transfusion, causes deleterious effects on vital organs. There currently are a number of chemical chelators in clinics to reduce iron concentration, for example , deferoxamine and deferiprone, but these produce diverse side effects. Hence, the need for a safe and effective iron chelator is demanded. To evaluate rigorously the potential of berberine on iron chelation and its anti-oxidant effect, 30 mice were divided into 5 groups of 6. Except for the control group, other groups received iron sucrose 5 times a week for 4 successive weeks as an i.p injection. Afterward, either berberine or deferoxamine was injected for 1 month. The mice were then euthanized and liver, kidney and lungs were carefully removed for biochemical and pathological analysis. In comparison with the iron group with an extraordinary amount of iron deposits, berberine (20 mg/kg/day) dramatically reduced iron sedimentation in all tissues ( P < 0.01). Moreover, berberine lowered clinical symptoms of iron overdose, including inflammation, fibrosis and tissue degeneration. In terms of the activity of antioxidant enzymes, catalase and superoxide dismutase, iron overdose greatly reduced their activity compared to the control group. Berberine progressively increased their activity in comparison with the controls by lowering oxidative conditions ( P < 0.05). Iron overdose similarly increased lipid peroxidation by increasing the level of malondialdehyde. Berberine promptly suppressed lipid peroxidation in an efficient manner and reduced the level of malondialdehyde, a marker of lipid peroxidation in the tissues. Accordingly, berberine, as a natural antioxidant compound, could adequately serve as a substitute for chemical chelators with fewer side effects and comparable effectiveness.

Macrophage polarization by potential nutraceutical compounds: A strategic approach to counteract inflammation in atherosclerosis

Chronic inflammation represents a main event in the onset and progression of atherosclerosis and is closely associated with oxidative stress in a sort of vicious circle that amplifies and sustains all stages of the disease. Key players of atherosclerosis are monocytes/macrophages. According to their pro- or anti-inflammatory phenotype and biological functions, lesional macrophages can release various mediators and enzymes, which in turn contribute to plaque progression and destabilization or, alternatively, lead to its resolution. Among the factors connected to atherosclerotic disease, lipid species carried by low density lipoproteins and pro-oxidant stimuli strongly promote inflammatory events in the vasculature, also by modulating the macrophage phenotyping. Therapies specifically aimed to balance macrophage inflammatory state are increasingly considered as powerful tools to counteract plaque formation and destabilization. In this connection, several molecules of natural origin have been recognized to be active mediators of diverse metabolic and signaling pathways regulating lipid homeostasis, redox state, and inflammation; they are, thus, considered as promising candidates to modulate macrophage responsiveness to pro-atherogenic stimuli. The current knowledge of the capability of nutraceuticals to target macrophage polarization and to counteract atherosclerotic lesion progression, based mainly on in vitro investigation, is summarized in the present review.

Berberine, A Phytoalkaloid, Inhibits Inflammatory Response Induced by LPS through NF-Kappaβ Pathway: Possible Involvement of the IKKα

Berberine (BBR), a plant alkaloid, is known for its therapeutic properties of anticancer, cardioprotective, antidiabetic, hypolipidemic, neuroprotective, and hepatoprotective activities. The present study was to determine the molecular mechanism of BBR's pharmacological activity in human monocytic (THP-1) cells induced by arachidonic acid (AA) or lipopolysaccharide (LPS). The effect of BBR on AA/LPS activated proinflammatory markers including TNF-α, MCP-1, IL-8 and COX-2 was measured by ELISA or quantitative real-time PCR. Furthermore, the effect of BBR on LPS-induced NF-κB translocation was determined by immunoblotting and confocal microscopy. AA/ LPS-induced TNF-α, MCP-1, IL-6, IL-8, and COX-2 markers were markedly attenuated by BBR treatment in THP-1 cells by inhibiting NF-κB translocation into the nucleus. Molecular modeling studies suggested the direct interaction of BBR to IKKα at its ligand binding site, which led to the inhibition of the LPS-induced NF-κB translocation to the nucleus. Thus, the present study demonstrated the anti-inflammatory potential of BBR via NF-κB in activated monocytes, whose interplay is key in health and in the pathophysiology of atherosclerotic development in blood vessel walls. The present study findings suggest that BBR has the potential for treating various chronic inflammatory disorders.

Berberine Protests the Heart from Ischemic Reperfusion Injury via Interference with Oxidative and Inflammatory Pathways

BACKGROUND

Ischemia and reperfusion (I/R) is a pathological condition characterized by an initial restriction of blood supply to an organ followed by the subsequent restoration of perfusion and concomitant reoxygenation.

OBJECTIVE

The aim of the study is to assess the possible cardioprotective potential effect of berberine in myocardial ischemia reperfusion injury induced by ligation of coronary artery in a male rat model.

METHODS

Total amount of 28 adult male albino rats were randomized into 4 equal groups: 1) Sham group, rats underwent the same anesthetic and surgical procedure as the control group except for LAD ligation; 2), Active control group, rats subjected to regional ischemia for 30 min by ligation of LAD coronary artery and reperfusion for 2 hours, 3), Control vehicle group, rats received dimethyl sulphoxide (DMSO) (vehicle of berberine) via IP route and subjected to ischemia for 30 minutes before ligation of LAD coronary artery & reperfusion for 2 hr; 4), Berberine treated group, rats pretreated with berberine10 mg/kg via IP injection 30minutes before ligation of LAD coronary artery & then subjected to reperfusion for 2 hr.

RESULTS

In the control group, as compared with sham, tissue TNF-α, IL-6, IL-10, caspase-3 and BAX, plasma cTn-T and serum MDA significantly increased (P<0.05), while serum GSH significantly decreased (P<0.05). The histopathological control group showed a significant cardiac injury (P<0.05) compared with the sham group. Berberine significantly counteracted (P<0.05) the increase of TNF-α, IL-6, caspase-3 and BAX and counteracted the increase in plasma cTn-T and serum MDA. Berberine produces a significant elevation (P<0.05) in cardiac IL-10 and serum GSH with a significant reduction in (P<0.05) cardiac injury.

CONCLUSION

Berberine attenuates myocardial I/R injury in male rats via interfering with inflammatory reactions and apoptosis which were induced by I/R injury.

Chinese Herbal Medicines and Active Metabolites: Potential Antioxidant Treatments for Atherosclerosis

Atherosclerosis is a complex chronic disease that occurs in the arterial wall. Oxidative stress plays a crucial role in the occurrence and progression of atherosclerotic plaques. The dominance of oxidative stress over antioxidative capacity generates excess reactive oxygen species, leading to dysfunctions of the endothelium and accelerating atherosclerotic plaque progression. Studies showed that Chinese herbal medicines and traditional Chinese medicine (TCM) might regulate oxidative stress; they have already been used to treat diseases related to atherosclerosis, including stroke and myocardial infarction. This review will summarize the mechanisms of oxidative stress in atherosclerosis and discuss studies of Chinese herbal medicines and TCM preparations treating atherosclerosis, aiming to increase understanding of TCM and stimulate research for new drugs to treat diseases associated with oxidative stress.

Efficacy of berberine in treatment of rheumatoid arthritis: From multiple targets to therapeutic potential

Rheumatoid arthritis is a systemic autoimmune disorder involved in persistent synovial inflammation. Berberine is a nature-derived alkaloid compound with multiple pharmacological activities in different pathologies, including RA. Recent experimental studies have clarified several determinant cellular and molecular targets of BBR in RA, and provided novel evidence supporting the promising therapeutic potential of BBR to combat RA. In this review, we recapitulate the therapeutic potential of BBR and its mechanism of action in ameliorating RA, and discuss the modulation of gut microbiota by BBR during RA. Collectively, BBR might be a promising lead drug with multi-functional activities for the therapeutic strategy of RA.

Berberine attenuates the inflammatory response by activating the Keap1/Nrf2 signaling pathway in bovine endometrial epithelial cells

Endometritis is a common inflammatory disease that disturbs the rapid development of dairy farming. In the present study, we investigated the anti-inflammatory effects of berberine on the LPS-induced inflammatory response in bovine endometrial epithelial cells (bEECs) and the participation of the Keap1/Nrf2 signaling pathway in this process. Berberine treatment significantly reduced the LPS-induced expression levels of CRP, IL-1β, IL-6, and TNF-α in bEECs. The Nrf2 signaling pathway in these cells was also activated by berberine. We further evaluated the effects of Nrf2 activators and inhibitors on the downregulation of proinflammatory cytokines. The activator of Nrf2 significantly inhibited the production of these proinflammatory cytokines that was induced by LPS. However, an inhibitor of Nrf2 only partially inhibited the anti-inflammatory effects of berberine on the LPS-induced inflammatory response in bEECs. In conclusion, our findings suggest that berberine exerts anti-inflammatory effects partially by activating the Keap1/Nrf2 signaling pathway.

A New Therapeutic Candidate for Cardiovascular Diseases: Berberine

Cardiovascular diseases (CVD) are the leading cause of death in the world. However, due to the limited effectiveness and potential adverse effects of current treatments, the long-term prognosis of CVD patients is still discouraging. In recent years, several studies have found that berberine (BBR) has broad application prospects in the prevention and treatment of CVD. Due to its effectiveness and safety for gastroenteritis and diarrhea caused by bacterial infections, BBR has been widely used in China and other Asian countries since the middle of the last century. The development of pharmacology also provides evidence for the multi-targets of BBR in treating CVD. Researches on CVD, such as arrhythmia, atherosclerosis, dyslipidemia, hypertension, ischemic heart disease, myocarditis and cardiomyopathy, heart failure, etc., revealed the cardiovascular protective mechanisms of BBR. This review systematically summarizes the pharmacological research progress of BBR in the treatment of CVD in recent years, confirming that BBR is a promising therapeutic option for CVD.

Phytotherapy for Cardiovascular Disease: A Bench-to-Bedside Approach

At present, cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide, and global trends suggest that this panorama will persist or worsen in the near future. Thus, optimization of treatment strategies and the introduction of novel therapeutic alternatives for CVD represent key objectives in contemporary biomedical research. In recent years, phytotherapy-defined as the therapeutic use of whole or minimally modified plant components-has ignited large scientific interest, with a resurgence of abundant investigation on a wide array of medicinal herbs (MH) for CVD and other conditions. Numerous MH have been observed to intervene in the pathophysiology of CVD via a myriad of molecular mechanisms, including antiinflammatory, anti-oxidant, and other beneficial properties, which translate into the amelioration of three essential aspects of the pathogenesis of CVD: Dyslipidemia, atherosclerosis, and hypertension. Although the preclinical data in this scenario is very rich, the true clinical impact of MH and their purported mechanisms of action is less clear, as large-scale robust research in this regard is in relatively early stages and faces important methodological challenges. This review offers a comprehensive look at the most prominent preclinical and clinical evidence currently available concerning the use of MH in the treatment of CVD from a bench-to-bedside approach.

Synergy Effects of Metformin and Berberine on Glyoxal-induced Carbonyl Stress in Isolated Rat Liver Mitochondria

Objective:

Carbonyl stress, resulting from toxic effects of alpha-dicarbonyls such as glyoxal (GO), plays an important role in mitochondrial dysfunction and subsequent development of diabetic complications. This study evaluated the ability of metformin (MET), berberine (BBR), and their combination to prevent GO-induced carbonyl stress in isolated rat liver mitochondria.

Methods:

Mitochondria (0.5 mg protein/mL) were isolated from the Wistar rat liver and incubated with various concentrations of GO (1, 2.5, 5, 7.5, and 10 mM) for 30 minutes and IC50 for GO was calculated. The suspensions of mitochondria were incubated with various concentrations of MET (2.5, 5, 10, and 20 mM) or BBR (2.5, 5, 10, and 20 μM) for 30 min and then GO in a dose of IC50 at 37 ºC for 30 min. Mitochondrial complex II activity, mitochondrial membrane potential (MMP), MDA level, reactive oxygen species (ROS) formation, reduced glutathione (GSH) content, and protein carbonylation were assessed. The combination index and isobologram of MET and BBR on GO toxicity were calculated.

Results:

IC50 of GO was assigned approximately 3 mM. GO disrupted the electron transfer chain and significantly increased mitochondrial ROS formation, protein carbonylation, and MDA level. GO decreased mitochondrial viability, MMP, and GSH content. Pre-treatment with MET and BBR could potentially reverse GO-induced deleterious effects in a concentration-dependent manner. Results of the drug combination indicated that CI for Fa 0.5 (Effect 50 %) was 0.83.

Conclusion:

These results suggest that BBR in combination with MET has a moderate synergistic effect on GO-induced carbonyl stress in isolated rat liver mitochondria.

Curcumin Prevents Neuroinflammation by Inducing Microglia to Transform into the M2-phenotype via CaMKKβ-dependent Activation of the AMP-Activated Protein Kinase Signal Pathway

BACKGROUND

Neuroinflammation plays an important role in the pathophysiological process of various neurodegenerative diseases. It is well known that curcumin has obvious anti-inflammatory effects in various neuroinflammation models. However, its effect on the modulation of microglial polarization is largely unknown.

OBJECTIVE

This study aimed to investigate whether curcumin changed microglia to an anti-inflammatory M2-phenotype by activating the AMP-activated protein kinase (AMPK) signaling pathway.

METHODS

LPS treatment was used to establish BV2 cells and primary microglia neuroinflammation models. The neuroinflammation mouse model was established by an intracerebroventricular (ICV) injection of lipopolysaccharide (LPS) in the lateral septal complex region of the brain. TNF-α was measured by ELISA, and cell viability was measured by Cell Counting Kit-8 (CCK-8). The expression of proinflammatory and anti-inflammatory cytokines was examined by Q-PCR and Western blot analysis. Phenotypic polarization of BV2 microglia was detected by immunofluorescence.

RESULTS

Curcumin enhanced AMPK activation in BV2 microglial cells in the presence and absence of LPS. Upon LPS stimulation, the addition of curcumin promoted M2 polarization of BV2 cells, as evidenced by suppressed M1 and the elevated M2 signature protein and gene expression. The effects of curcumin were inhibited by an AMPK inhibitor or AMPK knockdown. Calmodulin-dependent protein kinase kinase β (CaMKKβ) and liver kinase B1 (LKB1) are upstream kinases that activate AMPK. Curcumin can activate AMPK in Hela cells, which do not express LKB1. However, both the CaMKKβ inhibitor and siRNA blocked curcumin activation of AMPK in LPS-stimulated BV2 cells. Moreover, the CaMKKβ inhibitor and siRNA weaken the effect of curcumin suppression on M1 and enhancement of M2 protein and gene expression in LPS-stimulated BV2 cells. Finally, curcumin enhanced AMPK activation in the brain area where microglia were over-activated upon LPS stimulation in an in vivo neuroinflammation model. Moreover, curcumin also suppressed M1 and promoted M2 signature protein and gene expression in this in vivo model.

CONCLUSION

Curcumin enhances microglia M2 polarization via the CaMKKβ-dependent AMPK signaling pathway. Additionally, curcumin treatment was found to be neuroprotective and thus might be considered as a novel therapeutic agent to treat the neurodegenerative disease such as Alzheimer's disease, Parkinson's disease, etc.

Berberine as a Potential Multi-Target Agent for Metabolic Diseases: A Review of Investigations for Berberine

Berberine (BBR) is a botanic alkaloid extracted from Coptis chinensis (Huanglian), which has various properties, compassing anti-hyperglycemia, anti-obesity, anti-inflammation, and improves insulin resistance, etc. Several researches have confirmed that BBR has effective actions in treating glycolipid metabolic abnormalities. BBR is also beneficial in regulating intestinal flora. Metabolic diseases are strongly associated with metabolic disorders, which are growing in the population and dramatically impacting human health, which also have been considered as a leading cause of diseases and death globally. This review is to evaluate the metabolic properties of BBR, and its potential application to the treatment of metabolic diseases by its effective actions on metabolic disorders.

Berberine Inhibits the Gene Expression and Production of Proinflammatory Cytokines by Mononuclear Cells in Rheumatoid Arthritis and Healthy Individuals

OBJECTIVE

Rheumatoid arthritis (RA) is the most prevalent autoimmune arthritis. Berberine is an alkaloid isolated from Berberis vulgaris, and its anti-inflammatory effect has been identified.

METHODS

Twenty newly diagnosed RA patients and 20 healthy controls participated. Peripheral mononuclear cells were prepared and stimulated with bacterial lipopolysachharide (LPS,1 μg/ml), exposed to different concentrations of berberine (10 and 50μM) and dexamethasone (10-7 M) as a reference. The toxicity of compounds was evaluated by WST-1 assay. The expression of TNF-α and IL-1β was determined by quantitative real-time PCR. Protein level of secreted TNF-α and IL-1β was measured by using ELISA.

RESULTS

Berberine did not have any toxic effect on cells, whereas Lipopolysaccharide (LPS) stimulation caused a noticeable rise in TNF-α and IL-1β production. Berberine markedly downregulated the expression of both TNF-α and IL-1β, and inhibited TNF-α and IL-1β secretion from LPS-stimulated PBMCs.

DISCUSSION

This study provided a molecular basis for anti-inflammatory effect of berberine on human mononuclear cells through the suppression of TNF-a and IL-1secretion. Our findings highlighted the significant inhibitory effect of berberine on proinflammatory responses of mononuclear cells from rheumatoid arthritis individuals, which may be responsible for antiinflammatory property of Barberry. We observed that berberine at high concentration exhibited anti-inflammatory effect in PBMCs of both healthy and patient groups by suppression of TNF-a and IL-1cytokines at both mRNA and protein levels.

CONCLUSION

Berberine may inhibit the gene expression and production of pro-inflammatory cytokines by mononuclear cells in rheumatoid arthritis and healthy individuals without affecting cell viability. Future studies with a larger sample size are needed to prove the idea.

Pretreatment with berberine protects against cisplatin-induced renal injury in male Wistar rats

Berberine (BBR), an isoquinoline alkaloid, has been reported to be an antioxidant agent. This study was conducted to investigate the effect of BBR against nephrotoxicity induced by cisplatin (Cis) in male rats. In this experimental study, 28 Wistar male rats were randomly divided into four groups. Rats were pretreated with BBR (100 mg/kg/day, p.o.) for 7 consecutive days and Cis (7.5 mg/kg, i.p.) was administrated on the 7th day, 1 h after the last dose of BBR. Blood samples were collected to determine blood urea nitrogen (BUN) and creatinine (Cr) levels. Malondialdehyde (MDA), glutathione (GSH), protein carbonyl (PC), and nitric oxide (NO) levels and the activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and myeloperoxidase (MPO) were assessed in the left renal tissue. Also, the mRNA expression of SOD2 and PGx1 was measured in the left renal tissue. The right kidney was used for histopathological evaluation. Our results revealed that the levels of Cr, BUN, MDA, NO, and PC and the MPO activity increased by Cis administration. Also, we found that Cis decreased renal GSH level and SOD, GPx, and CAT activities. Pretreatment with BBR for 7 consecutive days significantly attenuated the Cis-induced nephrotoxicity via increasing the antioxidant capacity and reducing the oxidative stress indices in the renal tissue. Moreover, the renoprotective effect of BBR was confirmed by the histopathological evaluation of the kidneys. Our results indicated that BBR has produced amelioration in biochemical indices and oxidative stress parameters against Cis-induced nephrotoxicity.

Berberine: A Plant-derived Alkaloid with Therapeutic Potential to Combat Alzheimer's disease

Berberine (a protoberberine isoquinoline alkaloid) has shown promising pharmacological activities, including analgesic, anti-inflammatory, anticancer, antidiabetic, anti-hyperlipidemic, cardioprotective, memory enhancement, antidepressant, antioxidant, anti-nociceptive, antimicrobial, anti- HIV and cholesterol-lowering effects. It is used in the treatment of the neurodegenerative disorder. It has strong evidence to serve as a potent phytoconstituent in the treatment of various neurodegenerative disorders such as AD. It limits the extracellular amyloid plaques and intracellular neurofibrillary tangles. It has also lipid-glucose lowering ability, hence can be used as a protective agent in atherosclerosis and AD. However, more detailed investigations along with safety assessment of berberine are warranted to clarify its role in limiting various risk factors and AD-related pathologies. This review highlights the pharmacological basis to control oxidative stress, neuroinflammation and protective effect of berberine in AD, which will benefit to the biological scientists in understanding and exploring the new vistas of berberine in combating Alzheimer's disease.

Berberine Inhibits MDA-MB-231 Cells by Attenuating Their Inflammatory Responses

Breast cancer initiation is closely associated with cytokines that can change the inflammatory tumor microenvironment. Compounds extracted from plants have been explored for the possibility of cancer treatment in the recent decades. Berberine is an isoquinoline plant alkaloid with remarkable antioxidant and anti-inflammation roles, which is used in ethnic medicines, including traditional Chinese and North American medicine. In the present study, we investigated the effects of berberine on the malignant tumor cell behaviors in a breast cell line, MDA-MB-231. We found that berberine could not influence the cell viability in normal condition but was able to decrease the cancer cell migration capability in a scratch wound model and accordingly prolong the wound healing time. Furthermore, our results demonstrated that berberine inhibited the increased phosphorylation of c-Jun and c-Fos in these scratched cancer cells. With the cotreatment with LPS, which could boost the expression of cytokines in these cancer cells, berberine significantly reduced the increased expression of TNF-α and IL-6. Meanwhile, we found that berberine inhibited the activation of NF-κB by preventing the degradation of IκBα.

Hepatoprotective role of berberine against paraquat-induced liver toxicity in rat

Paraquat (PQ) is a herbicide agent commonly used in agricultural applications. Hepatotoxicity is among clinical complications associated with PQ intoxication. Oxidative stress and its subsequent events are major mechanisms identified in PQ-induced liver toxicity. Berberine (BBR) is a natural antioxidant widely investigated for its hepatoprotective effects. The present study designed to evaluate the potential cytoprotective properties of BBR against PQ-induced cytotoxicity in primary cultured rat hepatocytes and in vivo test of liver function enzymes. Cellular and biochemical parameters including lactate dehydrogenase (LDH), cell viability, ROS formation, glutathione (GSH) content, and mitochondrial membrane potential in the PQ-treated hepatocytes were measured, and the mentioned markers were evaluated in the presence of BBR. BBR treatment caused significant decrease in PQ-induced cell death, ROS formation, and LDH release. On the other hand, it was found that BBR inhibits cellular glutathione depletion in PQ-treated hepatocytes. Also, BBR treatment significantly diminished PQ-induced the liver function enzyme elevation. These data mention the potential hepatoprotective effect of BBR with therapeutic capability against PQ-induced liver damage.

gp91phox, a Novel Biomarker Evaluating Oxidative Stress, Is Elevated in Subclinical Hypothyroidism

BACKGROUND

gp91^phox, the catalytic core of NADPH oxidase (NOX) and biomarker of NOX activation, has been recently recognized as a parameter of systemic oxidative stress in several studies. Subclinical hypothyroidism (SH) is characteristic of elevated level of serum thyroid stimulating hormone (TSH) and is frequently accompanied with cholesterolemia. In this study, the levels of serum soluble gp91^phox were measured to assess the oxidative stress in patients with SH. And the relationship among gp91^phox, low-density lipoprotein-C (LDL-C), and TSH was also investigated.

METHODS

A total of 51 subjects were enrolled and categorized into four groups: the healthy controls subjects (n = 13), controls with high level of LDL-C alone (n = 12), SH with normal level of LDL-C (n = 11), and SH with high level of LDL-C (n = 15). The related clinical and laboratory data were collected for statistical analysis. All the patients were newly diagnosed and did not take any medication. The information of lipid profile and thyroid function was extracted, and the concentrations of gp91phox were obtained with ELISA.

RESULTS

The levels of serum soluble gp91phox evidently increased in the patients with SH with a high level of LDL-C (81.52 ± 37.00 ug/mL) as compared to the healthy controls (54.98 ± 1.83ug/mL, p < 0.001), controls with high level of LDL-C (61.21 ± 4.48 ug/mL, p=0.038) and SH with a normal level of LDL-C (62.82 ± 11.67ug/mL, p=0.027). Additionally, the levels of gp91^phox showed a significant positive correlation with both the levels of LDL-C (r = 0.595, p < 0.001) and TSH (r = 0.346, p=0.013) by the Spearman correlation analyses. The correlation remained significant even when the effect of another factor was controlled (TSH: when the effect of LDL-C was controlled, r = 0.453, p=0.001; LDL-C: when the effect of TSH was controlled, r = 0.291, p=0.040). The main effect analysis showed an independent main effect of either LDL-C (p = 0.041) or TSH (p=0.022) on gp91^phox without interaction (p=0.299).

CONCLUSIONS

Our work demonstrated that the levels of gp91^phox, a novel biomarker for measuring the oxidative stress, were significantly elevated in the patients with SH. And LDL-C and TSH were both independent predictors of gp91^phox. Abbreviations. BMI : Body mass index; TC : Total cholesterol; LDL-C : Low-density lipoprotein cholesterol; HDL-C : High-density lipoprotein cholesterol; TG : Triglyceride; FBG : Fasting blood glucose; FT3 : Free triiodothyronine; FT4 : Free thyroxine; TSH: Thyroid stimulating hormone; SBP : Systolic blood pressure; DBP : Diastolic blood pressure; SD : Standard deviation; LSD: Least significant difference.

Isosteroid alkaloids with different chemical structures from Fritillariae cirrhosae bulbus alleviate LPS-induced inflammatory response in RAW 264.7 cells by MAPK signaling pathway

Isosteroid alkaloids, natural products from Fritillariae Cirrhosae Bulbus, are well known for its antitussive, expectorant, anti-asthmatic and anti-inflammatory properties. However, the anti-inflammatory effect and its mechanism have not been fully explored. In this study, the anti-inflammatory activitives and the potential mechanisms of five isosteroid alkaloids from F. Cirrhosae Bulbus were investigated in lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells. The pro-inflammatory mediators and cytokines were measured by Griess reagent, ELISA and qRT-PCR. The expression of MAPKs was investigated by western blotting. Treatment with the five isosteroid alkaloids in appropriate concentrations could reduce the production of nitric oxide (NO), tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) in supernatant, and suppressed the mRNA expressions of TNF-α and IL-6. Meanwhile, the five isosteroid alkaloids significantly inhibited the phosphorylated activation of mitogen activated protein kinase (MAPK) signaling pathways, including extracellular signal-regulated kinase (ERK1/2), p38 MAPK and c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK). These results demonstrated that isosteroid alkaloids from F. Cirrhosae Bulbus exert anti-inflammatory effects by down-regulating the level of inflammatory mediators via mediation of MAPK phosphorylation in LPS-induced RAW264.7 macrophages, thus could be candidates for the prevention and treatment of inflammatory diseases.

Neuroprotective effects of berberine in animal models of Alzheimer's disease: a systematic review of pre-clinical studies

Background

Berberine is an isoquinoline alkaloid extracted from various Berberis species which is widely used in East Asia for a wide range of symptoms. Recently, neuroprotective effects of berberine in Alzheimer’s disease (AD) animal models are being extensively reported. So far, no clinical trial has been carried out on the neuroprotective effects of berberine. However, a review of the experimental data is needed before choosing berberine as a candidate drug for clinical experiments. We conducted a systematic review on AD rodent models to analyze the drug effects with minimal selection bias.

Methods

Five online literature databases were searched to find publications reporting studies of the effect of berberine treatment on animal models of AD. Up to March 2018, 15 papers were identified to describe the efficacy of berberine.

Results

The included 15 articles met our inclusion criteria with different quality ranging from 3 to 5. We analyzed data extracted from full texts with regard to pharmacological effects and potential anti-Alzheimer’s properties. Our analysis revealed that in multiple memory defects animal models, berberine showed significant memory-improving activities with multiple mechanisms, such as anti-inflammation, anti-oxidative stress, cholinesterase (ChE) inhibition and anti-amyloid effects.

Conclusion

AD is likely to be a complex disease driven by multiple factors. Yet, many therapeutic strategies based on lowering β-amyloid have failed in clinical trials. This suggest that the threapy should not base on a single cause of Alzheimer’s disease but rather a number of different pathways that lead to the disease. Overall we think that berberine can be a promising multipotent agent to combat Alzheimer’s disease.

The influence of alkaloids on oxidative stress and related signaling pathways

Alkaloids have always attracted scientific interest due to either their positive or negative effects on human beings. This review aims to summarize their antioxidant effects by both classical in vitro scavenging assay and at the cellular level. Since most in vitro studies used the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay, the results from those studies are summed up in the first part of the article. In the second part, available data on the effect of alkaloids on NADPH-oxidase, the key enzyme for reactive oxygen species production, at the cellular level, are summarized. More than 130 alkaloids were tested by DPPH assay. However, due to methodological differences, a direct comparison is hardly possible. It can be at least concluded that some of them were either similar to or even more active than standard antioxidants and the number of aromatic hydroxyl groups seems to be the major determinant for the activity. The data on inhibition of NADPH-oxidase activity by alkaloids demonstrated that there is little relationship to the DPPH assay. The mechanism seems to be based on inhibition of synthesis, activation or translocation of NADPH-oxidase subunits. In some alkaloids, activation of the nuclear factor Nrf2 pathway was documented to be the grounds for inhibition of NADPH-oxidase. Interestingly, many alkaloids can behave both as anti-oxidants and pro-oxidants depending on conditions and pro-oxidation might be the reason for activation of Nrf2. Available data on other "antioxidant" transcription factors FOXOs and PPARs are also mentioned.

Combating Neurodegenerative Diseases with the Plant Alkaloid Berberine: Molecular Mechanisms and Therapeutic Potential

Neurodegenerative diseases are among the most serious health problems affecting millions of people worldwide. Such diseases are characterized by a progressive degeneration and / or death of neurons in the central nervous system. Currently, there are no therapeutic approaches to cure or even halt the progression of neurodegenerative diseases. During the last two decades, much attention has been paid to the neuroprotective and anti-neurodegenerative activities of compounds isolated from natural products with high efficacy and low toxicity. Accumulating evidence indicates that berberine, an isoquinoline alkaloid isolated from traditional Chinese medicinal herbs, may act as a promising anti-neurodegenerative agent by inhibiting the activity of the most important pathogenic enzymes, ameliorating intracellular oxidative stress, attenuating neuroinflammation, triggering autophagy and protecting neurons against apoptotic cell death. This review attempts to summarize the current state of knowledge regarding the therapeutic potential of berberine against neurodegenerative diseases, with a focus on the molecular mechanisms that underlie its effects on Alzheimer's, Parkinson's and Huntington's diseases.

Ibuprofen prevents progression of ataxia telangiectasia symptoms in ATM-deficient mice

BACKGROUND

Inflammation plays a critical role in accelerating the progression of neurodegenerative diseases, such as Alzheimer's disease (AD) and ataxia telangiectasia (A-T). In A-T mouse models, LPS-induced neuroinflammation advances the degenerative changes found in cerebellar Purkinje neurons both in vivo and in vitro. In the current study, we ask whether ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), can have the opposite effect and delay the symptoms of the disease.

METHODS

We tested the beneficial effects of ibuprofen in both in vitro and in vivo models. Conditioned medium from LPS stimulated primary microglia (LM) applied to cultures of dissociated cortical neurons leads to numerous degenerative changes. Pretreatment of the neurons with ibuprofen, however, blocked this damage. Systemic injection of LPS into either adult wild-type or adult Atm-/- mice produced an immune challenge that triggered profound behavioral, biochemical, and histological effects. We used a 2-week ibuprofen pretreatment regimen to investigate whether these LPS effects could be blocked. We also treated young presymptomatic Atm-/- mice to determine if ibuprofen could delay the appearance of symptoms.

RESULTS

Adding ibuprofen directly to neuronal cultures significantly reduced LM-induced degeneration. Curiously, adding ibuprofen to the microglia cultures before the LPS challenge had little effect, thus implying a direct effect of the NSAID on the neuronal cultures. In vivo administration of ibuprofen to Atm-/- animals before a systemic LPS immune challenge suppressed cytological damage. The ibuprofen effects were widespread as microglial activation, p38 phosphorylation, DNA damage, and neuronal cell cycle reentry were all reduced. Unfortunately, ibuprofen only slightly improved the LPS-induced behavioral deficits. Yet, while the behavioral symptoms could not be reversed once they were established in adult Atm-/- animals, administration of ibuprofen to young mutant pups prevented their symptoms from appearing.

CONCLUSION

Inflammatory processes impact the normal progression of A-T implying that modulation of the immune system can have therapeutic benefit for both the behavioral and cellular symptoms of this neurodegenerative disease.

The Pathogenesis of Diabetes Mellitus by Oxidative Stress and Inflammation: Its Inhibition by Berberine

A substantial knowledge on the pathogenesis of diabetes mellitus (DM) by oxidative stress and inflammation is available. Berberine is a biologically active botanical that can combat oxidative stress and inflammation and thus ameliorate DM, especially type 2 DM. This article describes the potential of berberine against oxidative stress and inflammation with special emphasis on its mechanistic aspects. In diabetic animal studies, the modified levels of proinflammatory cytokines and oxidative stress markers were observed after administering berberine. In renal, fat, hepatic, pancreatic and several others tissues, berberine-mediated suppression of oxidative stress and inflammation was noted. Berberine acted against oxidative stress and inflammation through a very complex mechanism consisting of several kinases and signaling pathways involving various factors, including NF-κB (nuclear factor-κB) and AMPK (AMP-activated protein kinases). Moreover, MAPKs (mitogen-activated protein kinases) and Nrf2 (nuclear factor erythroid-2 related factor 2) also have mechanistic involvement in oxidative stress and inflammation. In spite of above advancements, the mechanistic aspects of the inhibitory role of berberine against oxidative stress and inflammation in diabetes mellitus still necessitate additional molecular studies. These studies will be useful to examine the new prospects of natural moieties against DM.

An in vitro comparative study of the antioxidant activity and SIRT1 modulation of natural compounds

Oxidative stress arises from an imbalance between the production of free radicals and antioxidant defences. Several studies have suggested that dietary antioxidants (such as polyphenols and berberine) may counteract oxidative stress through the involvement of the Sirtuin 1/Adenosine Monophosphate-Activated Protein Kinase (SIRT1/AMPK) pathway. The aim of this study was to evaluate the direct and specific antioxidant activity of some natural compounds, as well as their ability to modulate the expression of SIRT1 and the activation of AMPK. Quercetin, tyrosol, ferulic acid, catechin, berberine and curcumin were evaluated for their specific and direct antioxidant activity with TOSC assay. Their ability to modulate SIRT1 and AMPK was assessed by immunoblotting assay, while their cytotoxicity by CellTiter-Blue Cell Viability Assay. No statistically significant decrease (p > 0.05) in the number of viable cells was found upon challenging with the natural compounds. Quercetin exhibited the highest antioxidant activity against peroxyl radical and peroxinitrate derivates, while curcumin showed the best anti-hydroxyl activity with respect to the other compounds and, most importantly, respect to the reference antioxidants. Finally, all the tested compounds significantly increased the SIRT1 expression and the activation of AMPK. Our results clearly disclose the specific antioxidant activity of these natural compounds and their ability to increase SIRT1 expression and AMPK activation.

The effects of berberine on reactive oxygen species production in human neutrophils and in cell-free assays

The health benefits of berberine have been recognized for years. Even so, its effects on human neutrophils, the first line of immune defense, have not been reported. The purpose of this study was to investigate the effects of berberine on the human neutrophil oxidative burst. Reactive oxygen species production was analyzed by luminol-enhanced chemiluminescence. The analysis was performed in spontaneous and stimulated (phorbol myristate acetate (PMA) or opsonized zymosan particles (OZP)) whole blood and isolated neutrophils in the presence or absence of berberine. The effects of berberine on oxidant production in cell-free assays were evaluated using luminescence (H₂O₂-peroxidase-luminol) and fluorescence (Oxygen Radical Absorbance Capacity - ORAC) techniques. Berberine decreased the production of reactive oxygen species in human whole blood and isolated neutrophils stimulated with either PMA or OZP with a different efficiency (EC₅₀ was 69 μM and 197 μM for PMA and OZP, respectively). The effect was more pronounced in isolated neutrophils. Cell-free assays showed the antioxidant activity of berberine against peroxyl radicals and hydrogen peroxide. Based on our results, we suggest that the effects of berberine on reactive oxygen species production in human neutrophils are due to its antioxidant activity.

Rhizoma Coptidis and Berberine as a Natural Drug to Combat Aging and Aging-Related Diseases via Anti-Oxidation and AMPK Activation

Aging is the greatest risk factor for human diseases, as it results in cellular growth arrest, impaired tissue function and metabolism, ultimately impacting life span. Two different mechanisms are thought to be primary causes of aging. One is cumulative DNA damage induced by a perpetuating cycle of oxidative stress; the other is nutrient-sensing adenosine monophosphate-activated protein kinase (AMPK) and rapamycin (mTOR)/ ribosomal protein S6 (rpS6) pathways. As the main bioactive component of natural Chinese medicine rhizoma coptidis (RC), berberine has recently been reported to expand life span in Drosophila melanogaster, and attenuate premature cellular senescence. Most components of RC including berberine, coptisine, palmatine, and jatrorrhizine have been found to have beneficial effects on hyperlipidemia, hyperglycemia and hypertension aging-related diseases. The mechanism of these effects involves multiple cellular kinase and signaling pathways, including anti-oxidation, activation of AMPK signaling and its downstream targets, including mTOR/rpS6, Sirtuin1/ forkhead box transcription factor O3 (FOXO3), nuclear factor erythroid-2 related factor-2 (Nrf2), nicotinamide adenine dinucleotide (NAD⁺) and nuclear factor-κB (NF-κB) pathways. Most of these mechanisms converge on AMPK regulation on mitochondrial oxidative stress. Therefore, such evidence supports the possibility that rhizoma coptidis, in particular berberine, is a promising anti-aging natural product, and has pharmaceutical potential in combating aging-related diseases via anti-oxidation and AMPK cellular kinase activation.

The more effective treatment of atrial fibrillation applying the natural compounds; as NADPH oxidase and ion channel inhibitors

Atrial fibrillation (AF) is the most common cardiac arrhythmia that occurs because of several different risk factors, e.g., valvular heart disease, coronary artery disease, age ≥75 years, hypertension and diabetes mellitus. One key risk factor that results in AF, is oxidative stress. Evidence suggests that there is a correlation between oxidative processes and the genesis of AF. Oxidative stress occurs when the generation of reactive oxygen species (ROS) increase due to excessive activity of enzymes including NADPH oxidase (NOX) and xanthine oxidase; or its degradation decrease by dysfunctional antioxidant enzyme systems, such as superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx). Afterwards, elevated ROS may shift ion channel activity to increase AF susceptibility. The outbreak of AF continues to grow. Unfortunately, current treatment strategies may have limited efficacy or adverse effects. On the other hand, the inhibition of ROS formation and alteration of ion channel activity could be important therapeutic targets for prevention or treatments of AF. Additionally, many studies have been shown that several natural compounds have the ability to inhibit NADPH oxidases directly. This review focuses on natural compounds which specially inhibit NOX isoforms and have direct effects on ion channels, suggesting these compounds can be helpful in AF treatment.

Beneficial Effects of Berberine on Oxidized LDL-Induced Cytotoxicity to Human Retinal Müller Cells

Purpose

Limited mechanistic understanding of diabetic retinopathy (DR) has hindered therapeutic advances. Berberine, an isoquinolone alkaloid, has shown favorable effects on glucose and lipid metabolism in animal and human studies, but effects on DR are unknown. We previously demonstrated intraretinal extravasation and modification of LDL in human diabetes, and toxicity of modified LDL to human retinal Müller cells. We now explore pathogenic effects of modified LDL on Müller cells, and the efficacy of berberine in mitigating this cytotoxicity.

Methods

Confluent human Müller cells were exposed to in vitro–modified ‘highly oxidized, glycated (HOG-) LDL versus native-LDL (N-LDL; 200 mg protein/L) for 6 or 24 hours, with/without pretreatment with berberine (5 μM, 1 hour) and/or the adenosine monophosphate (AMP)-activated protein kinase (AMPK) inhibitor, Compound C (5 μM, 1 hour). Using techniques including Western blots, reactive oxygen species (ROS) detection assay, and quantitative real-time PCR, the following outcomes were assessed: cell viability (CCK-8 assay), autophagy (LC3, Beclin-1, ATG-5), apoptosis (cleaved caspase 3, cleaved poly-ADP ribose polymerase), oxidative stress (ROS, nuclear factor erythroid 2-related factor 2, glutathione peroxidase 1, NADPH oxidase 4), angiogenesis (VEGF, pigment epithelium-derived factor), inflammation (inducible nitric oxide synthase, intercellular adhesion molecule 1, IL-6, IL-8, TNF-α), and glial cell activation (glial fibrillary acidic protein).

Results

Native-LDL had no effect on cultured human Müller cells, but HOG-LDL exhibited marked toxicity, significantly decreasing viability and inducing autophagy, apoptosis, oxidative stress, expression of angiogenic factors, inflammation, and glial cell activation. Berberine attenuated all the effects of HOG-LDL (all P < 0.05), and its effects were mitigated by AMPK inhibition (P < 0.05).

Conclusions

Berberine inhibits modified LDL-induced Müller cell injury by activating the AMPK pathway, and merits further study as an agent for preventing and/or treating DR.

Novel role of the nutraceutical bioactive compound berberine in lectin-like OxLDL receptor 1-mediated endothelial dysfunction in comparison to lovastatin

BACKGROUND AND AIMS

Oxidized LDL (oxLDL) or pro-inflammatory stimuli lead to increased oxidative stress linked to endothelial dysfunction and atherosclerosis. The oxLDL receptor-1 (LOX1) is elevated within atheromas and cholesterol-lowering statins inhibit LOX1 expression. Berberine (BBR), an alkaloid extracted from plants of gender Berberis, has lipid-lowering and anti-inflammatory activity. However, its role in regulating LOX1-mediated signaling is still unknown. The aim of this study was to investigate the effect of BBR on oxLDL- and TNFα-induced endothelial dysfunction in human umbilical vein endothelial cells (HUVECs) and to compare it with that of lovastatin (LOVA).

METHODS AND RESULTS

Cytotoxicity was determined by lactate dehydrogenase assay. Antioxidant capacity was measured with chemiluminescent and fluorescent method and intracellular ROS levels through a fluorescent dye. Gene and protein expression levels were assayed by qRT-PCR and western blot, respectively. HUVECs exposure to oxLDL (30 μg/ml) or TNFα (10 ng/ml) for 24 h led to a significant increase in LOX1 expression, effect abrogated by BBR (5 μM) and LOVA (5 μM). BBR but not LOVA treatment abolished the TNFα-induced cytotoxicity and restored the activation of Akt signaling. In spite of a low direct antioxidant capacity, both compounds reduced intracellular ROS levels generated by treatment of TNFα but only BBR inhibited NOX2 expression, MAPK/Erk1/2 signaling and subsequent NF-κB target genes VCAM and ICAM expression, induced by TNFα.

CONCLUSIONS

These findings demonstrated for the first time that BBR could prevent the oxLDL and TNFα - induced LOX1 expression and oxidative stress, key events that lead to NOX, MAPK/Erk1/2 and NF-κB activation linked to endothelial dysfunction.

CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE

Berberine (PubChem CID: 2353); Lovastatin (PubChem CID: 53232).

Suppression of NFAT5-mediated Inflammation and Chronic Arthritis by Novel κB-binding Inhibitors

Nuclear factor of activated T cells 5 (NFAT5) has been implicated in the pathogenesis of various human diseases, including cancer and arthritis. However, therapeutic agents inhibiting NFAT5 activity are currently unavailable. To discover NFAT5 inhibitors, a library of > 40,000 chemicals was screened for the suppression of nitric oxide, a direct target regulated by NFAT5 activity, through high-throughput screening. We validated the anti-NFAT5 activity of 198 primary hit compounds using an NFAT5-dependent reporter assay and identified the novel NFAT5 suppressor KRN2, 13-(2-fluoro)-benzylberberine, and its derivative KRN5. KRN2 inhibited NFAT5 upregulation in macrophages stimulated with lipopolysaccharide and repressed the formation of NF-κB p65-DNA complexes in the NFAT5 promoter region. Interestingly, KRN2 selectively suppressed the expression of pro-inflammatory genes, including Nos2 and Il6, without hampering high-salt-induced NFAT5 and its target gene expressions. Moreover, KRN2 and KRN5, the latter of which exhibits high oral bioavailability and metabolic stability, ameliorated experimentally induced arthritis in mice without serious adverse effects, decreasing pro-inflammatory cytokine production. Particularly, orally administered KRN5 was stronger in suppressing arthritis than methotrexate, a commonly used anti-rheumatic drug, displaying better potency and safety than its original compound, berberine. Therefore, KRN2 and KRN5 can be potential therapeutic agents in the treatment of chronic arthritis.

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We identify a novel NFAT5 suppressor KRN2, 13-(2-fluoro)-benzylberberine, and its derivative KRN5 to inhibit NFAT5 activity.

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KRN2 inhibits the transcriptional activation of NFAT5 and the pro-inflammatory responses.

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KRN2 and KRN5 suppress experimentally induced arthritis in mice.

NFAT5 has been implicated in the pathogenesis of arthritis. However, therapeutic agents specifically inhibiting NFAT5 activity are currently unavailable. To discover NFAT5 inhibitors, a library of > 40,000 chemicals was screened, leading to the discovery of novel berberine-based NFAT5 suppressors, KRN2 and its oral derivative KRN5. KRN2 inhibited the transcriptional activation of NFAT5 by blocking NF-κB binding to the NFAT5 promoter region, thereby reducing the expression of pro-inflammatory genes. Moreover, KRN2 and KRN5 ameliorated experimentally induced arthritis in mice without serious adverse effects. Therefore, we propose that KRN2 and KRN5 may be potential therapeutic agents in the treatment of chronic arthritis.

Anti-arthritic effect of berberine on adjuvant-induced rheumatoid arthritis in rats

BACKGROUND

Rheumatoid arthritis (RA) is a chronic and systemic autoimmune disease, which affects approximately 1% adult population in the worldwide.

AIM

The present study was to investigate the anti-arthritic effect of berberine and its involved mechanism in Freund's complete adjuvant (FCA) induced arthritis rats.

METHODS AND MATERIALS

Rats were divided randomly into control, FCA, tripterysium glycosides, berberine (75 and 150mg/kg). The apparent indicators, including changes of body weights, paw swelling degrees and arthritis indexes, were analyzed to evaluate anti-arthritic effect of berberine. The levels of IL-6, IL-10, IL-17 and TGF-β in serum were measured by ELISA. Histopathological changes and immunohistochemical expression of anti-IL-10 and anti-IL-17 antibodies in ankle joint tissues were examined.

RESULTS

Berberine obviously suppressed the severity of RA rats by attenuating the apparent indicators as mentioned above. Meanwhile, berberine significantly decreased the levels of IL-6 and IL-17, and increased the levels of IL-10 and TGF-β. Histopathological examinations indicated that berberine attenuated the synovial hyperplasia and inflammatory cell infiltration in joint tissues. In addition, immunohistochemical results showed that the amount of anti-IL-10 antibody increased, while the amount of anti-IL-17 antibody decreased in ankle tissues of arthritis rats.

CONCLUSIONS

Our results showed that berberine exerted a superior anti-arthritic effect and the mechanism maybe involve the balance between Treg and Th17 cells.