Comprehensive Analysis of Berberis aristata DC. Bark Extracts: In Vitro and In Silico Evaluation of Bioaccessibility and Safety.

Berberine (BER) is an alkaloid found, together with other protoberberinoids (PROTBERs), in several species used in medicines and food supplements. While some herbal preparations containing BER and PROTBERs, such as Berberis aristata DC. bark extracts, have shown promising potential for human health, their safety has not been fully assessed. Recently, the EFSA issued a call for data to deepen the pharmacokinetic and pharmacodynamic understanding of products containing BER and PROTBERs and to comprehensively assess their safety, especially when used in food supplements. In this context, new data were collected in this work by assessing: (i) the phytochemical profile of 16 different commercial B. aristata dry extracts, which are among the most widely used preparations containing BER and PROTBERs in Europe; (ii) the In Vitro and In Silico investigation of the pharmacokinetic properties of BER and PROTBERs; (iii) the In Vitro cytotoxicity of selected extracts in different human cell lines, including tests on hepatic cells in the presence of CYP450 substrates; (iv) the effects of the extracts on cancer cell migration; and (v) the In Vitro molecular effects of extracts in non-cancer human cells. Results showed that commercial B. aristata extracts contain BER as the main constituent, with jatrorrhizine as main secondary PROTBER. BER and jatrorrhizine were found to have a good bioaccessibility rate, but they interact with P-gp. B. aristata extracts showed limited cytotoxicity and minimal interaction with CYP450 substrates. Furthermore, tested extracts demonstrated inhibition of cancer cell migration and were devoid of any pro-tumoral effects in normal cells. Overall, our work provides a valuable overview to better elucidate important concerns regarding botanicals containing BER and PROTBERs.

Enhanced Recognition of a Herbal Compound Epiberberine by a DNA Quadruplex-Duplex Structure.

The small molecule epiberberine (EPI) is a natural alkaloid with versatile bioactivities against several diseases including cancer and bacterial infection. EPI can induce the formation of a unique binding pocket at the 5' side of a human telomeric G-quadruplex (HTG) sequence with four telomeric repeats (Q4), resulting in a nanomolar binding affinity (KD approximately 26 nM) with significant fluorescence enhancement upon binding. It is important to understand (1) how EPI binding affects HTG structural stability and (2) how enhanced EPI binding may be achieved through the engineering of the DNA binding pocket. In this work, the EPI-binding-induced HTG structure stabilization effect was probed by a peptide nucleic acid (PNA) invasion assay in combination with a series of biophysical techniques. We show that the PNA invasion-based method may be useful for the characterization of compounds binding to DNA (and RNA) structures under physiological conditions without the need to vary the solution temperature or buffer components, which are typically needed for structural stability characterization. Importantly, the combination of theoretical modeling and experimental quantification allows us to successfully engineer Q4 derivative Q4-ds-A by a simple extension of a duplex structure to Q4 at the 5' end. Q4-ds-A is an excellent EPI binder with a KD of 8 nM, with the binding enhancement achieved through the preformation of a binding pocket and a reduced dissociation rate. The tight binding of Q4 and Q4-ds-A with EPI allows us to develop a novel magnetic bead-based affinity purification system to effectively extract EPI from Rhizoma coptidis (Huang Lian) extracts.

Current development and structure-activity relationship study of berberine derivatives.

Berberine is a quaternary ammonium isoquinoline alkaloid derived from traditional Chinese medicines Coptis chinensis and Phellodendron chinense. It has many pharmacological activities such as hypoglycemic, hypolipidemic, anti-tumor, antimicrobial and anti-inflammatory. Through structural modifications at various sites of berberine, the introduction of different groups can change berberine's physical and chemical properties, thereby improving the biological activity and clinical efficacy, and expanding the scope of application. This paper reviews the research progress and structure-activity relationships of berberine in recent years, aiming to provide valuable insights for the exploration of novel berberine derivatives.

Jiao-tai-wan and its effective component-coptisine alleviate cognitive impairment in db/db mice through the JAK2/STAT3 signaling pathway.

BACKGROUND: Cognitive impairment (CI) is now well-accepted as a complication and comorbidity of diabetes mellitus (DM), becoming a serious medical and social problem. Jiao-tai-wan (JTW), one of noted traditional Chinese medicine (TCM), showed dual therapeutic effects on DM and CI. Nevertheless, the potential mechanism is unclear. PURPOSE: This study sought to investigate the mechanism how JTW protected against DM and CI and screen the active component in JTW. METHODS: Db/db mice were used as mouse models. Mice were treated by gavage with 0.9 % saline (0.1 mL/10g/d), low dose of JTW (2.4 g/kg/d) or high dose of JTW (4.8 g/kg/d) for 8 weeks separately. To access the effects of JTW, the levels of OGTT, HOMA-IR, blood lipids, inflammatory cytokines in serum and hippocampus were measured, behavioral tests were conducted, and histopathological changes were observed. The mechanism exploration was performed via network pharmacology, RT-qPCR, western blot, and immunofluorescence staining (IF). The impact and mechanism of coptisine in vitro were investigated using BV2 cells induced by LPS as cellular models. In vitro experiments were conducted in two parts. The first part comprised four groups: Control group, LPS group, LPS+LCOP group and LPS+HCOP group. The second part consisted of four groups: Control group, LPS group, LPS+HCOP group, and LPS+ Fed group. The western blot and RT-qPCR methods were used to examine the changes in biomarkers of the JAK2/STAT3 signaling pathways in BV2 cells. RESULTS: The results demonstrated that JTW could improve OGTT and HOMA-IR, reduce the serum levels of LDL-C, HDL-C, TG, and TC, restore neuronal dysfunction and synaptic plasticity, and decrease the deposition of Aß in the hippocampus. The findings from ELISA, IF, and RT-qPCR revealed that JTW could alleviate microglial activation and inflammatory status in vivo and coptisine could play the same role in vitro. Moreover, the changes of the JAK2/STAT3 signaling pathway in LPS-induced BV2 cells or hippocampus of db/db mice were distinctly reversed by coptisine or JTW, respectively. CONCLUSION: Our study suggested that JTW and its effective component coptisine could alleviate diabetes mellitus-related cognitive impairment, closely linked to the JAK2/STAT3 signaling pathway.

Coptisine alleviates colitis through modulating gut microbiota and inhibiting TXNIP/NLRP3 inflammasome.

ETHNOPHARMACOLOGICAL RELEVANCE: Ulcerative colitis (UC) is a disease involving the enteric canal which is characterised by chronisch inflammatory reaction. Coptisine (COP), the distinctive component of Coptis chinensis Franch., is famous for its anti-inflammation, antioxidation, anti-bacteria, and anti-cancer. Earlier researches certified that COP is a prospective remedy for colitis, but the mechanism of colitis and the therapeutical target of COP are deficiently elucidated. AIM OF THIS STUDY: In this follow-up study, we adopted dextran sulfate sodium (DSS)-elicited UC model to further elucidate the possible mechanism of COP on UC in mice. MATERIALS AND METHODS: COP and the positive drug sulfasalazine (SASP) were administered by oral gavage in DSS-induced colitis mouse model. Oxidative stress, inflammatory cytokines, intestinal barrier permeability, protein expression of the TXNIP/NLRP3 inflammasome pathway and intestinal microbiome structure were assessed. RESULTS: Among this investigation, our team discovered that COP could mitigate DSS-elicited UC in murines, with prominent amelioration in weight loss, disease activity index, intestinal permeability (serum diamine oxidase and D-lactate), contracted colonal length and histologic alterations. Furthermore, COP greatly lowered the generation of pro-inflammatory factors, malondialdehyde (MDA) activity and reactive oxygen species (ROS) level, while increased superoxide dismutase (SOD) activity in colonal tissues. Additionally, COP downmodulated the proteic expressions of thioredoxin-interacting protein (TXNIP), NOD-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein (ASC), caspase-1, IL-1ß and IL-18. Enteric microbiome sequencing displayed that DSS and COP tremendously influenced the constitution and diversity of enteric microbes in DSS-elicited UC murines. Besides, COP elevated the abundance of probiotic bacteria Bacteroidota, Akkermansia_muciniphila and Bacteroides_acidifaciens, lowered the proportions of potential pathogenic bacteria, such as Lachnospiraceae, Acetatifactor_muris, Clostridium_XlVa, Alistipes and Oscillibacter, and reduced the ratio of Bacillota/Bacteroidota, which vastly helped to reverse the enteric microbiome to a balanceable condition. Alterations in these bacteria were strongly correlated with the colitis relative index. CONCLUSION: The mechanism of COP against UC is connected with the suppression of TXNIP/NLRP3 inflammasome signalling pathway and the adjustment of the enteric microbiome profiles. The proofs offer new understandings upon the anti-UC function of COP, which might be a prospective candidate against UC.

Rhizoma coptidis can inhibit the excessive proliferation, inflammation, and transformation of lung fibroblasts into myofibroblasts.

BACKGROUND: Pulmonary fibrosis (PF) is a chronic, progressive, and irreversible heterogeneous disease of lung interstitial tissue. To combat progression of PF, new drugs are required to be developed. Rhizoma coptidis (COP), one of the main alkaloids of Coptis chinensis, is a traditional herbal medicine used to treat various inflammatory diseases. OBJECTIVE: To investigate the possible effects of Coptisine (Cop) on the growth, inflammation, as well as FMT of TNF-ß1-induced HFL1 cells and uncover the mechanism. MATERIAL AND METHODS: Human fetal lung fibroblast 1 (HFL1) was induced using 6ng/mL TGF-ß1 as a model of pulmonary fibrosis. CCK-8, Brdu, and transwell assays indicated the effects on cell growth as well as motility. qPCR and the corresponding kits indicted the effects on cell inflammation. Immunoblot showed the effects on FMT and further confirmed the mechanism. RESULTS: Coptisine inhibits excessive growth as well as motility of TNF-ß1-induced HFL1 cells. It further inhibits inflammation and ROS levels in TNF-ß1-induced HFL1 cells. Coptisine inhibits the FMT process of TNF-ß1-induced HFL1 cells. Mechanically, coptisine promotes the Nrf2/HO-1 pathway. CONCLUSION: Coptisine can inhibit the excessive growth, inflammation as well as FMT of lung fibroblasts into myofibroblasts. It could serve as a promising drug of PF.

9-O-monoethyl succinate berberine effectively blocks the PI3K/AKT signaling pathway by targeting Wnt5a protein in inhibiting osteosarcoma growth.

BACKGROUND: Osteosarcoma (OS) is the most common primary bone malignancy, mainly affecting children, adolescents, and young adults, followed by the elderly, with a high propensity for local invasion and metastasis. Although surgery combined with chemotherapy has greatly improved the prognosis of patients with OS, the prognosis for metastatic or recurrent OS is still unsatisfactory. The research community has struggled to develop an effective chemotherapy treatment regimen for this tumor. For the creation of an OS drug, our research team has effectively developed and manufactured a new drug named 9-O-monoethyl succinate berberine (B2). PURPOSE: In this study, we aimed to investigate the roles and functions of B2 in the treatment of OS. METHODS: Human OS cell lines and mouse OS cell lines were used in vitro cell experiments, while BALB/c mice and BALB/c nude mice were used in vivo animal experiments. To investigate the molecular mechanism of B2 treatment, antibody microarray analysis, proteomic analysis, quantitative real-time PCR, immunohistochemical labeling, and western blotting analysis were mostly carried out. We assessed the impact of B2 on OS therapy and the underlying molecular pathways based on in vivo and in vitro studies. RESULTS: Our findings demonstrated that B2 has the ability to inhibit the proliferation, migration, and invasion of OS cell lines, while also induce apoptosis in vitro. Additionally, our results suggested that B2 could effectively impede the growth of OS and has less heart and lung damage than cisplatin in vivo. In terms of mechanism, we discovered that the Wnt5a protein is significantly expressed in OS cell lines. Knockdown of Wnt5a can restrict OS cell lines proliferation, and overexpression of Wnt5a had the opposite results. B2 also had a strong affinity with Wnt5a and can inhibit the PI3K/AKT signaling pathway by targeting Wnt5a. Tumor cells proliferation can be inhibited by blocking the PI3K/AKT signaling pathway, and Wnt5a-mediated inactivation of the PI3K/AKT signaling pathway after B2 treatment. In vitro and in vivo experiments with Wnt5a overexpression, B2 significantly inhibited tumor growth, migration, and invasion. Moreover, B2 and Wnt5a also have a strong structural binding ability (binding energy of -7.567 ± 0.084 kcal/mol, binding values of 2.860 ± 0.434 µM), and three hydrogen bonds are generated at the docking positions of amino acids GLN286, ASN288, and ASN292. CONCLUSION: In summary, our study confirmed for the first time that the growth of OS is related to abnormal overexpression of Wnt5a protein, and designed a novel small molecule inhibitor named B2 targeting Wnt5a protein, which inhibits OS growth by mediating PI3K/AKT signaling pathway by targeting Wnt5a protein. Our research laid the groundwork for the promotion of B2 as a new anticancer drug and revealed an innovative chemotherapeutic strategy for OS therapy.

Discovery and evolution of berberine analogues as anti-Helicobacter pylori agents with multi-target mechanisms.

Thirty protoberberine derivatives, of which twenty five were new, were synthesized and evaluated for their anti-Helicobacter pylori (HP) activities, taking 2,3,10-trimethoxy-9-p-methylbenzylaminoprotopalmatine chloride 1 as the lead. Among them, berberine (BBR) derivative 7c displayed the highest potency against six tested metronidazole (MTZ)-resistant strains and two tested MTZ-susceptible strains with the MIC values of 0.4-1.6 µg/mL with favorable druglike profiles including low toxicity and high stabilities in plasma and artificial gastric fluid. Mechanistic study revealed that 7c might target HP urease with IC50 value of 0.27 µg/mL against Jack bean urease. Furthermore, 7c might change the permeability of the bacterial membrane and direct interact with HP DNA, which also contribute to its bactericidal activity. Therefore, BBR derivatives constituted a new family of anti-HP candidates, with the advantage of good safety profile and multi-target mechanisms, and are worthy for further investigation.

Berberine analog of chloramphenicol exhibits a distinct mode of action and unveils ribosome plasticity.

Chloramphenicol (CHL) is an antibiotic targeting the peptidyl transferase center in bacterial ribosomes. We synthesized a new analog, CAM-BER, by substituting the dichloroacetyl moiety of CHL with a positively charged aromatic berberine group. CAM-BER suppresses bacterial cell growth, inhibits protein synthesis in vitro, and binds tightly to the 70S ribosome. Crystal structure analysis reveals that the bulky berberine group folds into the P site of the peptidyl transferase center (PTC), where it competes with the formyl-methionine residue of the initiator tRNA. Our toe-printing data confirm that CAM-BER acts as a translation initiation inhibitor in stark contrast to CHL, a translation elongation inhibitor. Moreover, CAM-BER induces a distinct rearrangement of conformationally restrained nucleotide A2059, suggesting that the 23S rRNA plasticity is significantly higher than previously thought. CAM-BER shows potential in avoiding CHL resistance and presents opportunities for developing novel berberine derivatives of CHL through medicinal chemistry exploration.

Differences in Metabolite Profiles of Dihydroberberine and Micellar Berberine in Caco-2 Cells and Humans-A Pilot Study.

We investigated the pharmacokinetic pathway of berberine and its metabolites in vitro, in Caco-2 cells, and in human participants following the administration of dihydroberberine (DHB) and micellar berberine (LipoMicel®, LMB) formulations. A pilot trial involving nine healthy volunteers was conducted over a 24 h period; blood samples were collected and subjected to Ultra High-Performance Liquid Chromatography-High Resolution Mass Spectrometry (UHPLC-HRMS) analyses to quantify the concentrations of berberine and its metabolites. Pharmacokinetic correlations indicated that berberrubine and thalifendine follow distinct metabolic pathways. Additionally, jatrorrhizine sulfate appeared to undergo metabolism differently compared to the other sulfated metabolites. Moreover, berberrubine glucuronide likely has a unique metabolic pathway distinct from other glucuronides. The human trial revealed significantly higher blood concentrations of berberine metabolites in participants of the DHB treatment group compared to the LMB treatment group-except for berberrubine glucuronide, which was only detected in the LMB treatment group. Similarly, results from in vitro investigations showed significant differences in berberine metabolite profiles between DHB and LMB. Dihydroberberine, dihydroxy-berberrubine/thalifendine and jatrorrhizine sulfate were detected in LMB-treated cells, but not in DHB-treated cells; thalifendine and jatrorrhizine-glucuronide were detected in DHB-treated cells only. While DHB treatment provided higher blood concentrations of berberine and most berberine metabolites, both in vitro (Caco-2 cells) and in vivo human studies showed that treatment with LMB resulted in a higher proportion of unmetabolized berberine compared to DHB. These findings suggest potential clinical implications that merit further investigation in future large-scale trials.

Tetrahydroberberrubine exhibits preventive effect on obesity by activating PGC1α-mediated thermogenesis in white and brown adipose tissue.

The escalating prevalence of obesity presents formidable challenges, necessitating the development of effective therapeutic strategies. In this study, we aimed to elucidate the preventive effects on obesity of tetrahydroberberrubine (THBru), a derivative of berberine (BBR) and to unravel its underlying mechanism. Using an obese mouse model induced by a high-fat diet (HFD), THBru was found to markedly ameliorate obesity, as evidenced by reduced body weight, decreased Lee's index, diminished fat mass in epididymal white adipose tissue (WAT) and brown adipose tissue (BAT), alongside improved dyslipidemia. Notably, at the same dose, THBru exhibited superior efficacy compared to BBR. RNA-sequencing and gene set enrichment analysis indicated THBru activated thermogenesis, which was further confirmed in WAT, BAT, and 3T3-L1 cells. Bioinformatics analysis of RNA-sequencing data revealed the candidate gene Pgc1α, a key regulator involved in thermogenesis. Moreover, THBru was demonstrated to elevate the expression of PGC1α by stabilizing its mRNA in WAT, BAT and 3T3-L1 cells. Furthermore, PGC1α knockdown blocked the pro-thermogenic and anti-obesity action of THBru both in vivo and in vitro. This study unravels the preventive effects of THBru on obesity through the activation of PGC1α-mediated thermogenesis, thereby delineating its potential therapeutic implications for obesity and associated disorders.

Integrative analysis of metabolomics and proteomics reveals mechanism of berberrubine-induced nephrotoxicity.

Berberrubine (BRB), a main metabolite of berberine, has stronger hypoglycemic and lipid-lowering activity than its parent form. We previously found that BRB could cause obvious nephrotoxicity, but the molecular mechanism involved remains unknown. In this study, we systematically integrated metabolomics and quantitative proteomics to reveal the potential mechanism of nephrotoxicity caused by BRB. Metabolomic analysis revealed that 103 significant- differentially metabolites were changed. Among the mentioned compounds, significantly upregulated metabolites were observed for phosphorylcholine, sn-glycerol-3-phosphoethanolamine, and phosphatidylcholine. The top three enriched KEGG pathways were the mTOR signaling pathway, central carbon metabolism in cancer, and choline metabolism in cancer. ERK1/2 plays key roles in all three metabolic pathways. To further confirm the main signaling pathways involved, a proteomic analysis was conducted to screen for key proteins (such as Mapk1, Mapk14, and Caspase), indicating the potential involvement of cellular growth and apoptosis. Moreover, combined metabolomics and proteomics analyses revealed the participation of ERK1/2 in multiple metabolic pathways. These findings indicated that ERK1/2 regulated the significant- differentially abundant metabolites determined via metabolomics analysis. Notably, through a cellular thermal shift assay (CETSA) and molecular docking, ERK1/2 were revealed to be the direct binding target involved in BRB-induced nephrotoxicity. To summarize, this study sheds light on the understanding of severe nephrotoxicity caused by BRB and provides scientific basis for its safe use and rational development.

Berberine increases the killing effect of pirarubicin on HCC cells by inhibiting ATG4B-autophagy pathway.

Pirarubicin (THP) is a new generation of cell cycle non-specific anthracycline-based anticancer drug. In the clinic, THP and THP combination therapies have been shown to be effective in hepatocellular carcinoma (HCC) patients with transcatheter arterial chemoembolization (TACE) without serious side effects. However, drug resistance limits its therapeutic efficacy. Berberine (BBR), an isoquinoline alkaloid, has been shown to possess antitumour properties against various malignancies. However, the synergistic effect of BBR and THP in the treatment of HCC is unknown. In the present study, we demonstrated for the first time that BBR sensitized HCC cells to THP, including enhancing THP-induced growth inhibition and apoptosis of HCC cells. Moreover, we found that BBR sensitized THP by reducing the expression of autophagy-related 4B (ATG4B). Mechanistically, the inhibition of HIF1α-mediated ATG4B transcription by BBR ultimately led to attenuation of THP-induced cytoprotective autophagy, accompanied by enhanced growth inhibition and apoptosis in THP-treated HCC cells. Tumor-bearing experiments in nude mice showed that the combination treatment with BBR and THP significantly suppressed the growth of HCC xenografts. These results reveal that BBR is able to strengthen the killing effect of THP on HCC cells by repressing the ATG4B-autophagy pathway, which may provide novel insights into the improvement of chemotherapeutic efficacy of THP, and may be conducive to the further clinical application of THP in HCC treatment.

Coptisine-mediated downregulation of E2F7 induces G2/M phase arrest in hepatocellular carcinoma cells through inhibition of E2F4/NFYA/NFYB transcription factors.

Coptisine (COP) has been shown to exhibit a wide range of anticancer properties, including in hepatocellular carcinoma (HCC). Nevertheless, the precise mechanism of COP in the treatment of HCC remains elusive. This study aims to investigate the potential mechanism of action of COP against HCC. By evaluating the anti-HCC activity of COP in different HCC cells lines and in xenografted nude mice, it was found that COP inhibited HCC in vitro and in vivo. Through RNA-Seq analysis, E2F7 was identified as a potential target of COP against HCC, as well as the cell cycle as a possible pathway. The overexpression of E2F7 and the inhibition of CHK1 demonstrated that COP inhibits the activity of HCC and induces G2/M phase arrest of HCC cells by down-regulating E2F7 and influencing the CHK1/CDC25A pathway. Finally, the promoter fragmentation experiments and chromatin immunoprecipitation revealed that COP down-regulated E2F7 by inhibiting the E2F4/NFYA/NFYB transcription factors. In conclusion, our study demonstrated that COP downregulates E2F7 by affecting key transcription factors, thereby inducing cell cycle arrest and inhibits HCC cell growth. This provides further evidence of the efficacy of COP in the treatment of tumors.

Berberine inhibits the progression of breast cancer by regulating METTL3-mediated m6A modification of FGF7 mRNA.

BACKGROUND: Berberine (BBR), an isoquinoline alkaloid from Coptidis rhizoma, has been found to have powerful activities against various human malignancies, including breast cancer. However, the underlying antitumor mechanisms of BBR in breast cancer remain poorly understood. METHODS: Breast cancer cells were cultured and treated with different doses (0, 20, 40, and 60 µM) of BBR for 48 h. Cell viability, proliferation, apoptosis, invasion, and migration were assessed using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transwell, and wound healing assays. Fibroblast growth factor 7 (FGF7), methyltransferase-like 3 (METTL3), and insulin-like growth factor-2 mRNA-binding protein 3 (IGF2BP3) mRNA levels and protein levels were measured using real-time quantitative polymerase chain reaction (RT-qPCR) and western blot. Interaction between METTL3 and FGF7 m6A was assessed using methylated RNA immunoprecipitation (MeRIP)-qPCR and RNA immunoprecipitation (RIP) assay. Binding ability between IGF2BP3 and FGF7 mRNA was analyzed using RIP assay. RESULTS: BBR treatment hindered breast cancer cell proliferation, invasion, migration, and induced apoptosis. FGF7 expression was upregulated in breast cancer tissues, while its level was reduced in BBR-treated tumor cells. FGF7 upregulation relieved the repression of BBR on breast cancer cell malignant behaviors. In mechanism, METTL3 stabilized FGF7 mRNA through the m6A-IGF2BP3-dependent mechanism and naturally improved FGF7 expression. BBR treatment inhibited breast cancer growth in vivo. CONCLUSION: BBR treatment blocked breast cancer cell growth and metastasis partly by regulating METTL3-mediated m6A modification of FGF7 mRNA, providing a promising therapeutic target for breast cancer treatment.

Epiberberine: a potential rumen microbial urease inhibitor to reduce ammonia release screened by targeting UreG.

Rumen microbial urease inhibitors have been proposed for regulating nitrogen emission and improving nitrogen utilization efficiency in ruminant livestock industry. However, studies on plant-derived natural inhibitors of rumen microbial urease are limited. Urease accessory protein UreG, plays a crucial role in facilitating urease maturation, is a new target for design of urease inhibitor. The objective of this study was to select the potential effective inhibitor of rumen microbial urease from major protoberberine alkaloids in Rhizoma Coptidis by targeting UreG. Our results showed that berberine chloride and epiberberine exerted superior inhibition potential than other alkaloids based on GTPase activity study of UreG. Berberine chloride inhibition of UreG was mixed type, while inhibition kinetics type of epiberberine was uncompetitive. Furthermore, epiberberine was found to be more effective than berberine chloride in inhibiting the combination of nickel towards UreG and inducing changes in the second structure of UreG. Molecular modeling provided the rational structural basis for the higher inhibition potential of epiberberine, amino acid residues in G1 motif and G3 motif of UreG formed interactions with D ring of berberine chloride, while interacted with A ring and D ring of epiberberine. We further demonstrated the efficacy of epiberberine in the ruminal microbial fermentation with low ammonia release and urea degradation. In conclusion, our study clearly indicates that epiberberine is a promising candidate as a safe and effective inhibitor of rumen microbial urease and provides an optimal strategy and suitable feed additive for regulating nitrogen excretion in ruminants in the future. KEY POINTS: • Epiberberine is the most effective inhibitor of rumen urease from Rhizoma Coptidis. • Urease accessory protein UreG is an effective target for design of urease inhibitor. • Epiberberine may be used as natural feed additive to reducing NH3 release in ruminants.

Compound-compound interaction analysis of baicalin and berberine derivatives in aqueous solution.

Baicalin and berberine are biologically active constituents of the crude drugs Scutellaria root and Coptis rhizome/Phellodendron bark, respectively. Baicalin and berberine are reported to combine together as a 1:1 complex that forms yellow precipitates by electrostatic interaction in decoctions of Kampo formulae containing these crude drugs. However, the structural basis and mechanism for the precipitate formation of this compound-compound interaction in aqueous solution remains unclarified. Herein, we searched for berberine derivatives in the Coptis rhizome that interact with baicalin and identified the chemical structures involved in the precipitation formation. Precipitation assays showed that baicalin formed precipitates with berberine and coptisine but not with palmatine and epiberberine. Thus, the 2,3-methylenedioxy structure may be crucial to the formation of the precipitates, and electrostatic interaction is necessary but is not sufficient. In this multicomponent system experiment, palmatine formed a dissociable complex with baicalin and may competitively inhibit the formation of berberine and coptisine precipitation with baicalin. Therefore, the precipitation formed by berberine and baicalin was considered to be caused by the aggregation of the berberine-baicalin complex, and the 2,3-methylenedioxy structure is likely crucial to the aggregation of the complex.

Protective Effects of Coptis chinensis Rhizome Extract and Its Constituents (Berberine, Coptisine, and Palmatine) against α-Synuclein Neurotoxicity in Dopaminergic SH-SY5Y Cells.

Parkinson's disease (PD) is a common neurodegenerative disease with progressive loss of dopaminergic neurons in substantia nigra and the presence of α-synuclein-immunoreactive inclusions. Gaucher's disease is caused by homozygous mutations in ß-glucocerebrosidase gene (GBA). GBA mutation carriers have an increased risk of PD. Coptis chinensis (C. chinensis) rhizome extract is a major herb widely used to treat human diseases. This study examined the association of GBA L444P mutation with Taiwanese PD in 1016 cases and 539 controls. In addition, the protective effects of C. chinensis rhizome extract and its active constituents (berberine, coptisine, and palmatine) against PD were assayed using GBA reporter cells, LC3 reporter cells, and cells expressing mutated (A53T) α-synuclein. Case-control study revealed that GBA L444P carriers had a 3.93-fold increased risk of PD (95% confidence interval (CI): 1.37-11.24, p = 0.006) compared to normal controls. Both C. chinensis rhizome extract and its constituents exhibited chemical chaperone activity to reduce α-synuclein aggregation. Promoter reporter and endogenous GBA protein analyses revealed that C. chinensis rhizome extract and its constituents upregulated GBA expression in 293 cells. In addition, C. chinensis rhizome extract and its constituents induced autophagy in DsRed-LC3-expressing 293 cells. In SH-SY5Y cells expressing A53T α-synuclein, C. chinensis rhizome extract and its constituents reduced α-synuclein aggregation and associated neurotoxicity by upregulating GBA expression and activating autophagy. The results of reducing α-synuclein aggregation, enhancing GBA expression and autophagy, and protecting against α-synuclein neurotoxicity open up the therapeutic potentials of C. chinensis rhizome extract and constituents for PD.

Unraveling the enigma: Molecular mechanisms of berberrubine-induced nephrotoxicity reversed by its parent form berberine.

BACKGROUND: Berberine is an isoquinoline alkaloid that is extensively applied in the clinic due to its potential therapeutic effects on dysentery and infectious diarrhoea. Its main metabolite, berberrubine, a promising candidate for ameliorating hyperlipidaemia, has garnered more attention than berberine. However, our study revealed that berberrubine induces severe kidney damage, while berberine was proven to be safe. PURPOSE: Herein, we explored the opposite biological effects of these two compounds on the kidney and elucidated their underlying mechanisms. METHODS: First, integrated metabolomic and proteomic analyses were conducted to identify relevant signalling pathways. Second, a click chemistry method combined with a cellular thermal shiftassay, a drug affinity responsive target stability assay, and microscale thermophoresis were used to identify the direct target proteins. Moreover, a mutation experiment was performed to study the specific binding sites. RESULTS: Animal studies showed that berberrubine, but not berberine, induced severe chronic, subchronic, and acute nephrotoxicity. More importantly, berberine reversed the berberrubine-reduced nephrotoxicity. The results indicated that the cPLA2 signalling pathway was highly involved in the nephrotoxicity induced by berberrubine. We further confirmed that the direct target of berberrubine is the BASP1 protein (an upstream factor of cPLA2 signalling). Moreover, berberine alleviated nephrotoxicity by binding cPLA2 and inhibiting cPLA2 activation. CONCLUSION: This study is the first to revel the opposite biological effects of berberine and its metabolite berberrubine in inducing kidney injury. Berberrubine, but not berberine, shows strong nephrotoxicity. The cPLA2 signalling pathway can be activated by berberrubine through targeting of BASP1, while berberine inhibits this pathway by directly binding with cPLA2. Our study paves the way for studies on the exact molecular targets of herbal ingredients. We also demonstrated that natural small molecules and their active metabolites can have opposite regulatory roles in vivo through the same signalling pathway.

The study on synthesis and vitro hypolipidemic activity of novel berberine derivatives nitric oxide donors.

Berberine was used as the lead compound in the present study to design and synthesize novel berberine derivatives by splicing bromine bridges of different berberine carbon chain lengths coupled nitric oxide donors, and their lipid lowering activities were assessed in a variety of ways. This experiment synthesized 17 new berberine nitric oxide donor derivatives. Compared with berberine hydrochloride, most of the compounds exhibited certain glycerate inhibitory activity, and compounds 6a, 6b, 6d, 12b and 12d showed higher inhibitory activity than berberine, with 6a, 6b and 6d having significant inhibitory activity. In addition, compound 6a linked to furazolidone nitric oxide donor showed better NO release in experiments; In further mechanistic studies, we screened and got two proteins, PCSK9 and ACLY, and docked two proteins with 17 compounds, and found that most of the compounds bound better with ATP citrate lyase (ACLY), among which there may be a strong interaction between compound 6a and ACLY, and the interaction force was better than the target drug Bempedoic Acid, which meaning that 6a may exert hypolipidemic effects by inhibiting ACLY; moreover, we also found that 6a may had the better performance in gastrointestinal absorption, blood-brain barrier permeability, Egan, Muegge class drug principle model calculation and bioavailability.