Biochemical pathways in the antiatherosclerotic effect of berberine:

Recent advances in total synthesis of protoberberine and chiral tetrahydroberberine alkaloids

Covering: Up to 2024Due to the widespread distribution of protoberberine alkaloids (PBs) and tetrahydroberberine alkaloids (THPBs) in nature, coupled with their myriad unique physiological activities, they have garnered considerable attention from medical practitioners. Over the past few decades, synthetic chemists have devised various total synthesis methods to attain these structures, continually expanding reaction pathways to achieve more efficient synthetic strategies. Simultaneously, the chiral construction of THPBs has become a focal point. In this comprehensive review, we categorically summarized the developmental trajectory of the total synthesis of these alkaloids based on the core closure strategies of protoberberine and tetrahydroberberine.

Therapeutic Effects of Berberine on Liver Fibrosis are associated With Lipid Metabolism and Intestinal Flora

Liver cirrhosis is a form of liver fibrosis resulting from chronic hepatitis caused by various liver diseases, such as viral hepatitis, alcoholic liver damage, nonalcoholic steatohepatitis, autoimmune liver disease, and by parasitic diseases such as schistosomiasis. Liver fibrosis is the common pathological base and precursors of cirrhosis. Inflammation and disorders of lipid metabolism are key drivers in liver fibrosis. Studies have determined that parts of the arachidonic acid pathway, such as its metabolic enzymes and biologically active products, are hallmarks of inflammation, and that aberrant peroxisome proliferator-activated receptor gamma (PPARγ)-mediated regulation causes disorders of lipid metabolism. However, despite the ongoing research focus on delineating the mechanisms of liver fibrosis that underpin various chronic liver diseases, effective clinical treatments have yet to be developed. Berberine (BBR) is an isoquinoline alkaloid with multiple biological activities, such as anti-inflammatory, anti-bacterial, anti-cancer, and anti-hyperlipidemic activities. Many studies have also found that BBR acts via multiple pathways to alleviate liver fibrosis. Furthermore, the absorption of BBR is increased by nitroreductase-containing intestinal flora, and is strengthened via crosstalk with bile acid metabolism. This improves the oral bioavailability of BBR, thereby enhancing its clinical utility. The production of butyrate by intestinal anaerobic bacteria is dramatically increased by BBR, thereby amplifying butyrate-mediated alleviation of liver fibrosis. In this review, we discuss the effects of BBR on liver fibrosis and lipid metabolism, particularly the metabolism of arachidonic acid, and highlight the potential mechanisms by which BBR relieves liver fibrosis through lipid metabolism related and intestinal flora related pathways. We hope that this review will provide insights on the BBR-based treatment of liver cirrhosis and related research in this area, and we encourage further studies that increase the ability of BBR to enhance liver health.

An insight into the medicinal attributes of berberine derivatives: A review

In the last few decades, traditional natural products have been the center of attention for the scientific community and exploration of their therapeutic abilities is proceeding perpetually. Berberine, with remarkable therapeutic diversity, is a plant derived isoquinoline alkaloid which is widely used as a traditional medicine in China. Berberine has been tackled as a fascinating pharmacophore to make great contributions to the discovery and development of new therapeutic agents against variegated diseases. Despite its tremendous therapeutic potential, clinical utility of this alkaloid was significantly compromised due to undesirable pharmacokinetic properties. To overcome this limitation, several structural modifications were performed on this scaffold to improve its therapeutic efficacy. The collective efforts of the community have achieved the tremendous advancements, bringing berberine to clinical use and discovering new therapeutic opportunities by structural modifications on the berberine scaffold. In this review, recent advancements in the medicinal chemistry of berberine and its derivatives in the last few years (2016-2020) have been compiled to represent inclusive data associated with various biological activities of this alkaloid. The comprehensive structure-activity relationship studies along with molecular modelling and mechanistic studies have also been summarized. This article would be highly helpful for the scientific community to get better insight into medicinal research of berberine and become a compelling guide for the rational design of berberine based compounds.

Berberine Ameliorates Brain Inflammation in Poloxamer 407-Induced Hyperlipidemic Rats

Purpose

Hyperlipidemia, which promotes the development of atherosclerosis, ischemic stroke, and other forms of brain injury, can be induced by poloxamer-407. Berberine is a primary pharmacological active component of Coptidis Rhizoma that has a number of therapeutic activities. This study investigated the effects of berberine on poloxamer-407-induced brain inflammation by evaluating its effects on short-term memory, cell proliferation, inflammation, and apoptosis in the hippocampus.

Methods

To induce hyperlipidemia in a rat model, 500 mg/kg of poloxamer-407 was injected intraperitoneally. Berberine was orally administered to the rats in the berberine-treated groups once a day for 4 weeks. The step-down task avoidance task was performed to measure short-term memory. An analysis of serum lipids, immunohistochemistry for 5-bromo-2′-deoxyuridine, glial fibrillary acidic protein (GFAP), and ionized calcium-binding adapter molecule 1 (Iba1) in the dentate gyrus, and western blot analysis for Bax, Bcl-2, and cytochrome c in the hippocampus were performed.

Results

In hyperlipidemic rats, berberine reduced the levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol and increased the level of high-density lipoprotein cholesterol in hyperlipidemic rats. Berberine also increased cell proliferation and short-term memory, as well as decreasing the expression of GFAP, Iba1, Bax, and cytochrome c and increasing Bcl-2 expression.

Conclusions

Berberine treatment improved short-term memory in hyperlipidemia by increasing neuronal proliferation and inhibiting neuronal apoptosis. Berberine treatment also improved lipid metabolism.

Poor permeability and absorption affect the activity of four alkaloids from Coptis

Coptidis rhizoma (Coptis) and its alkaloids exert various pharmacological functions in cells and tissues; however, the oral absorption of these alkaloids requires further elucidation. The present study aimed to examine the mechanism underlying the poor absorption of alkaloids, including berberine (BER), coptisine (COP), palmatine (PAL) and jatrorrhizine (JAT). An ultra‑performance liquid chromatography (UPLC) method was validated for the determination of BER, COP, PAL and JAT in the above experimental medium. In addition, the apparent oil‑water partition coefficient (Po/w); apparent permeability coefficient (Papp), determined using a parallel artificial membrane permeability assay (PAMPA) plate; membrane retention coefficient (R %); and effect of P‑glycoprotein (P‑gp) inhibitor on the Papp of the four alkaloids were investigated. The intestinal absorption rate constant (Ka) and absorption percentage (A %) of the four alkaloids were also determined. The results of the present study demonstrated that the Po/w of the four alkaloids in 0.1 mol·l‑1 HCl medium was significantly higher (P<0.01), compared with those of the alkaloids in phosphate buffer (pH 7.4). The Papp of BER was 1.0‑1.2x10‑6 cm·s‑1, determined using a PAMPA plate, and the Papp of BER, COP, PAL and JAT decreased sequentially. The concentrations of the four alkaloids on the apical‑to‑basolateral (AP‑BL) surface and the basolateral‑to‑apical (BL‑AP) surface increased in a linear manner, with increasing concentrations between 10 and 100 µmol. In addition, the transportation of BER on the BL‑AP surface was significantly faster (P<0.01), compared with that on the AP‑BL surface and, following the addition of verpamil (a P‑gp inhibitor), the Papp (AP‑BL) of the four alkaloids increased, whereas the Papp (BL‑AP) was significantly decreased (P<0.01). The rat intestinal perfusion experiment demonstrated that the four alkaloids were poorly absorbed; however, the Ka of BER was significantly higher, compared with the three other alkaloids. Furthermore, the A % and Ka provided evidence that the absorption of BER was increased in the jejunum, compared with in the ileum. In conclusion, the four alkaloids from Coptis appeared to be poorly absorbed, determined using a shake flask, pre‑coated PAMPA plates, a Caco‑2 cell monolayer model and intestinal perfusion; however, absorption was higher in the jejunum than in the ileum. Among the four alkaloids, the permeability of BER was markedly higher than the others, and P‑gp efflux had a significant effect on the absorption of those alkaloids.

Interaction of herbal compounds with biological targets: a case study with berberine

Berberine is one of the main alkaloids found in the Chinese herb Huang lian (Rhizoma Coptidis), which has been reported to have multiple pharmacological activities. This study aimed to analyze the molecular targets of berberine based on literature data followed by a pathway analysis using the PANTHER program. PANTHER analysis of berberine targets showed that the most classes of molecular functions include receptor binding, kinase activity, protein binding, transcription activity, DNA binding, and kinase regulator activity. Based on the biological process classification of in vitro berberine targets, those targets related to signal transduction, intracellular signalling cascade, cell surface receptor-linked signal transduction, cell motion, cell cycle control, immunity system process, and protein metabolic process are most frequently involved. In addition, berberine was found to interact with a mixture of biological pathways, such as Alzheimer's disease-presenilin and -secretase pathways, angiogenesis, apoptosis signalling pathway, FAS signalling pathway, Hungtington disease, inflammation mediated by chemokine and cytokine signalling pathways, interleukin signalling pathway, and p53 pathways. We also explored the possible mechanism of action for the anti-diabetic effect of berberine. Further studies are warranted to elucidate the mechanisms of action of berberine using systems biology approach.

Berberine on metabolic and cardiovascular risk factors: an analysis from preclinical evidences to clinical trials

INTRODUCTION

Type 2 diabetes mellitus and hypercholesterolemia have proven to give an increased incidence of cardiovascular diseases (CVD). Recent studies have suggested that the natural alkaloid berberine could have pharmacological activities potentially useful in diabetes and hypercholesterolemia management.

AREAS COVERED

The aim of this review is to evaluate the metabolic properties of the natural alkaloid berberine, and its potential application to the treatment of diabetes and CVD prevention.

EXPERT OPINION

Berberine proved to be effective in improving glycemic control and lipid profile. The modern investigation on berberine pharmacological activity is actually developing and numerous scientific evidences are actually in progress and reported in international congresses. The near future perspective is the isolation or neo-synthesis of berberine analogs with a higher bioavailability. The anti-hyperlipidemic and anti-diabetic effects of berberine have to be related to markers of improvement in organ damage in humans; longer trials are needed to better evaluate the safety profile of the molecule, when administered alone or in association with other anti-hyperlipidemic or anti-diabetic drugs, especially in the European population.

Berberine ameliorates inflammation in patients with acute coronary syndrome following percutaneous coronary intervention

1. Inflammation is central to the pathogenesis of acute coronary syndrome (ACS) and is associated with adverse clinical outcomes after percutaneous coronary intervention (PCI). Recent in vitro work has demonstrated the anti-inflammatory effect of berberine, a primary component of the traditional Chinese medicine 'umbellatine'. In the present study, we further tested whether berberine had any beneficial effects on ACS patients following PCI. 2.In all, 130 ACS patients undergoing PCI were recruited to the present study. Sixty-one patients were treated with berberine (300 mg, t.i.d., for 30 days) in addition to standard therapy, whereas the remaining patients received standard therapy alone. Circulating inflammatory markers were measured by ELISA, whereas serum lipid profiles were measured by routine chemical assays. 3.In the berberine-treated group, matrix metalloproteinase (MMP)-9, intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, C-reactive protein, interleukin-6 and monocyte chemoattractant protein-1 were significantly reduced relative to baseline values. Furthermore, the changes in MMP-9, ICAM-1 and VCAM-1 from baseline to after 1 month of treatment differed significantly between the two patient groups. There was a tendency for berberine to induce a slightly greater reduction in low-density lipoprotein cholesterol and triglycerides than standard therapy alone, without affecting high-density lipoprotein cholesterol, but the differences failed to reach statistical significance. No severe adverse effects of berberine were observed. 4.The results of the present study provide the first clinical evidence of the anti-inflammatory action of berberine in ACS patients following PCI. Berberine may become adjunct therapy to further improve clinical outcomes via its anti-inflammatory effect in ACS patients.

Suppression of oxLDL-induced MMP-9 and EMMPRIN expression by berberine via inhibition of NF-κB activation in human THP-1 macrophages

Upregulation of matrix metalloproteinases (MMPs) and extracellular matrix metalloproteinase inducer (EMMPRIN) by macrophages leads to atherosclerotic plaque rupture by degradation of the extracellular matrix. NF-κB activation regulates many key inflammatory genes linked to atherosclerosis. In the present study, the function of berberine, a natural extract from Rhizoma coptidis, on MMP-9 and EMMPRIN expression, the role of NF-κB activation in oxLDL-stimulated macrophages, and the possible mechanism in which NF-κB activation is involved were investigated. Berberine inhibited the expression of MMP-9 and EMMPRIN at both mRNA and protein levels. The phosphorylation of IκB-α and nuclear translocation of p65 protein were reduced by berberine, suggesting that NF-κB activation was inhibited by berberine in oxLDL-stimulated macrophages. Overall, berberine suppressed the expression of MMP-9 and EMMPRIN by at least reducing partly the activity of NF-κB in oxLDL-induced macrophages.

Berberine inhibits NADPH oxidase mediated superoxide anion production in macrophagesThis article is one of a selection of papers published in a Special Issue on Oxidative Stress in Health and Disease

Oxidative stress and amplified redox signaling contribute to the pathogenesis of many human diseases including atherosclerosis. The superoxide-generating phagocytic NADPH oxidase is a key source of oxidative stress in the developing atheroma. The aim of the present study was to examine the effect of berberine, a plant-derived alkaloid, on NADPH oxidase-mediated superoxide anion production in macrophages. Lipopolysaccharide (LPS) treatment activated NADPH oxidase in THP-1 monocyte-derived macrophages and increased the intracellular level of superoxide anions. Preincubation of cells with berberine demonstrated a concentration-dependent (10–50 µmol/L) and time-dependent (6–24 h) inhibition of superoxide anion generation in LPS-stimulated macrophages. Cell viability tests confirmed that berberine, at concentrations sufficient for inhibiting NADPH oxidase-mediated superoxide anion generation in macrophages, did not affect cell viability. Real-time PCR analysis revealed that addition of berberine to the culture medium was able to reduce gp91phox mRNA expression in LPS-treated cells. Berberine also restored superoxide dismutase (SOD) activity, which was found to be inhibited by LPS treatment. In conclusion, results from the present study demonstrate that berberine can effectively reduce intracellular superoxide levels in LPS- stimulated macrophages. Such a restoration of cellular redox by berberine is mediated by its selective inhibition of gp91phox expression and enhancement of SOD activity. The therapeutic relevance of berberine in the prevention and management of atherosclerosis remains to be further investigated.