Phytochemistry of Genus Buxus and Pharmacology of Cyclovirobuxine D.

BACKGROUND: Genus Buxus plants, commonly known as "boxwood", are widely distributed in China. The stems, branches, and leaves of the plant are traditionally used for rheumatism, toothache, chest pain, abdominal gas, and other diseases. However, an overview of the genus Buxus remains to be provided. PURPOSE: To provide a scientific basis for the appropriate use and further research the recent advancements in the traditional usage, phytochemistry, and, pharmacology of Buxus. STUDY DESIGN: Chemical composition and pharmacological correlation studies through a literature review. METHODS: Between 1970 and 2023, the available data concerning Buxus was compiled from online scientific sources, such as Sci-Finder, PubMed, CNKI, Google Scholar, and the Chinese Pharmacopoeia. Plant names were verified from "The Plant List" (http://www.theplantlist.org/). RESULTS: To date, 266 structurally diverse chemicals have been extracted and identified from the genus Buxus. Alkaloids constitute one of its primary bioactive phytochemicals. A summary of the channels of action of Cyclovirobuxine D on the cytotoxicity of a variety of cancers has been provided. CONCLUSION: Numerous findings from contemporary phytochemical and pharmacological studies support the traditional use, facilitating its application. Further research is necessary to address various shortcomings, including the identification of the active ingredients and quality control of the genus Buxus.

Cyclovirobuxine D inhibits hepatocellular carcinoma growth by inducing ferroptosis of hepatocellular carcinoma cells.

OBJECTIVE: Hepatocellular carcinoma (HCC) is one cancer with high death rates. Nowadays, there are no effective drugs to treat it. Cyclovirobuxine D (CVB-D) is the primary ingredient of the traditional Chinese medicine (TCM) Buxus microphylla. Here, we try to explore the impacts of CVB-D on human HCC cells and explain the potential mechanisms. METHODS: HepG2 and Huh-7 cells were used for our experiments. The cell viability and half inhibitory concentration (IC50) were detected by MTT assays. The apoptosis ratio was examined by Annexin V-FITC/7AAD staining and flow cytometry (FCM). The Fe2+ content was examined by ferrous ion content assays. The malondialdehyde (MDA) content was evaluated by lipid peroxidation MDA assays. The reactive oxygen species (ROS) level was examined by the DCFH-DA probe. The expression of apoptotic markers (Bax and Bcl-2) and ferroptosis-related proteins (GPX4 and FSP1) was detected by western blotting. The in vivo curative effect of CVB was explored using xenograft models established in C-NKG mice. RESULTS: The cell viability could be inhibited by CVB-D in HepG2 and Huh-7 cells. The IC50 value of CVB-D on HepG2 and Huh-7 cells are 91.19 and 96.29 µM at 48 h, and 65.60 and 72.80 µM at 72 h. FCM showed that the apoptosis rate was increased by CVB-D in HepG2 and Huh-7 cells. Next, ferrous ion content assays showed that the level of Fe2+ was increased by CVB-D in HepG2 and Huh-7 cells. Then, we found the level of MDA and ROS was increased by CVB-D. And the Fe2+ promotion by CVB-D could be reversed by Fer-1. Additionally, western blotting assays showed that the expression of GPX4 and FSP1 was inhibited by CVB-D in HepG2 and Huh-7 cells. Moreover, in vivo, CVB-D displayed excellent anticancer effects in HCC tumor-bearing C-NKG mice. CONCLUSION: CVB-D suppresses the growth in HCC cells through ferroptosis.

Cyclovirobuxine D alleviates aldosterone-induced myocardial hypertrophy by protecting mitochondrial function depending on the mutual regulation of Nrf2-SIRT3.

BACKGROUND: Cyclovirobuxine D (CVB-D) is a natural alkaloid that exhibits multiple pharmacological activities, such as anti-inflammatory, anti-oxidative stress, and anti-cancer properties. However, its specific protective mechanism of action for myocardial hypertrophy remains unresolved. PURPOSE: This work was to investigate the ameliorative impact of CVB-D in myocardial hypertrophy, and to elucidate aldosterone (ALD)-induced myocardial hypertrophy by inhibiting the SIRT3 mediated Nrf2 activation. METHODS: The myocardial hypertrophy model was reproduced by ALD both in vitro and in vivo, and the protective effect of CVB-D on myocardium and mitochondria was evaluated by TEM, H&E, qPCR, Western blot and ChIP. An immunoprecipitation experiment was adopted to evaluate the acetylation level of Nrf2 and the binding between SIRT3 and Nrf2. Additionally, bardoxolone-methyl (BAR, an Nrf2 agonist), ML385 (an Nrf2 inhibitor), resveratrol (RES, a SIRT3 agonist), and 3-TYP (a SIRT3 inhibitor) were used to confirm the molecular mechanism of CVB-D. Lastly, a molecular docking technique was employed to predict the binding site of SIRT3 and Nrf2 proteins. RESULTS: Our findings suggested that CVB-D improved mitochondrial function, leading to a reduction in ALD-induced cardiomyocyte hypertrophy. By CVB-D treatment, there was an activation of mutual regulation between Nrf2 and SIRT3. Specifically, CVB-D resulted in the increase of Nrf2 protein in the nucleus and activated Nrf2 signaling pathway, thus up-regulating SIRT3. The activation of SIRT3 and the protective action of mitochondrion disappeared because of the intervention of ML385. After CVB-D activated SIRT3, the acetylation level of Nrf2 decreased, followed by activating the Nrf2 pathway. The activation of Nrf2 and mitochondrial protection by CVB-D were reversed by 3-TYP. Our results are also supported by Co-IP and molecular docking analysis, revealing that CVB-D promotes SIRT3-mediated Nrf2 activation. CONCLUSION: Thus, CVB-D ameliorates ALD-induced myocardial hypertrophy by recovering mitochondrial function by activating the mutual regulation of Nrf2 and SIRT3. Thus, CVB-D could be a beneficial drug for myocardial hypertrophy.

Cyclovirobuxine D pretreatment ameliorates septic heart injury through mitigation of ferroptosis.

Myocardial dysfunction is a frequent complication in patients with severe sepsis. However, effective drugs for the prevention of myocardial dysfunction and the molecular mechanisms of the disease remain elusive. The present study demonstrated that Cyclovirobuxine D (CVB-D) could improve cardiac dysfunction in a cecal ligation and puncture (CLP) model in rodents and in a lipopolysaccharide (LPS) model in vitro. Echocardiography and histopathological examination were used to detect changes in cardiac structure and function. Kits were used to detect indicators of cardiac injury, transmission electron microscopy to detect structural changes in mitochondria and reverse transcription-quantitative PCR to detect prostaglandin-endoperoxide synthase 2 and hamp expression levels. L-Glutathione and malondialdehyde levels and superoxide dismutase activity were measured using kits. Cell viability was measured with the Cell Counting Kit-8. Iron metabolism-related proteins, inflammatory factor levels and related pathway proteins were detected using western blot analysis. Changes in L-type calcium currents were detected by membrane clamp, and contractility of cardiomyocytes was measured by Ion Optix. CVB-D attenuated CLP-induced cardiac malfunction in septic rats, with changes observed in myocardial pathological structure, creatine kinase isoenzyme (CK-MB), lactate dehydrogenase (LDH) and cardiac troponin I (cTnI). CVB-D attenuated sepsis-induced lipid peroxidation and iron overload. In addition, CVB-D decreased the expression of CK-MB, LDH and cTnI, suppressed oxidative stress index levels and reduced the production of reactive oxygen species. CVB-D decreased LPS-induced cytoplasmic iron overload by increasing upregulation of iron uptake molecules. Conversely, CVB-D significantly increased the upregulation of ferroportin 1. CVB-D pretreatment significantly reduced the levels of hamp mRNA compared with the LPS-treated group. CVB-D pretreatment significantly reduced inflammatory factor levels and the ratio of phosphorylated vs. total signal transducer and activator of transcription 3. The expression of SLC7A11 and GPX4 was upregulated in septic cells pretreated with CVB-D, however treatment with ML385 largely decreased this upregulation. Of note, CVB-D inhibited the inward flow of calcium ions through the LTCC. In conclusion, these findings suggest that CVB-D alleviated sepsis-induced cardiac iron toxicity by alleviating iron metabolism.

Cyclovirobuxine D inhibits growth and progression of non­small cell lung cancer cells by suppressing the KIF11­CDC25C­CDK1­CyclinB1 G2/M phase transition regulatory network and the NFκB/JNK signaling pathway.

Lung cancer is the leading cause of cancer­related mortality worldwide. Non­small cell lung cancer (NSCLC) is the most common pathological subtype of lung cancer and is associated with low 5­year overall survival rates. Therefore, novel and effective chemotherapeutic drugs are urgently required for improving the survival outcomes of patients with lung cancer. Cyclovirobuxine D (CVB­D) is a natural steroidal alkaloid, used for the treatment of cardiovascular diseases in Traditional Chinese Medicine. Several studies have also demonstrated the antitumor effects of CVB­D. Therefore, in the present study, the therapeutic effects of CVB­D in lung cancer and the underlying mechanisms were investigated using the in vivo xenograft model of NSCLC in nude mice and in vitro experiments with the NSCLC cell lines. Bioinformatics analyses of RNA­sequencing data, and cell­based functional assays demonstrated that CVB­D treatment significantly inhibited in vitro and in vivo NSCLC cell proliferation, survival, invasion, migration, angiogenesis, epithelial­to­mesenchymal transition and G2/M phase cell cycle. CVB­D exerted its antitumor effects by inhibiting the KIF11­CDK1­CDC25C­cyclinB1 G2/M phase transition regulatory oncogenic network and the NF­κB/JNK signaling pathway. CVB­D treatment significantly reduced the sizes and weights and malignancy of xenograft NSCLC tumors in the nude mice. In conclusion, the present study demonstrated that CVB­D inhibited the growth and progression of NSCLC cells by inhibiting the KIF11­CDK1­CDC25C­CyclinB1 G2/M phase transition regulatory network and the NF­κB/JNK signaling pathway. Therefore, CVB­D is a promising drug for the treatment of NSCLC patients.

Cyclovirobuxine D Ameliorates Experimental Diabetic Cardiomyopathy by Inhibiting Cardiomyocyte Pyroptosis via NLRP3 in vivo and in vitro.

Diabetic cardiomyopathy (DCM) is one of the common complications of diabetic patients, which can induce myocardial hypertrophy, cardiac fibrosis, and heart failure. Growing evidence has shown that the occurrence and development of DCM are accompanied by pyroptosis which is an NLRP3-mediated intense inflammatory cell death. Cyclovirobuxine D (CVB-D) has been shown to significantly ameliorate DCM and anti-inflammatory effects associated with cardiomyopathy, but it is unclear whether it has an effect on cardiomyocyte pyroptosis accompanying DCM. Therefore, the purpose of the present study was to explore the ameliorating effect of CVB-D on cardiomyocyte pyroptosis associated with DCM and its molecular regulation mechanism. Type 2 diabetes in C57BL/6 mice was reproduced by the high-fat and high-glucose diet (HFD) combined with low-dose streptozotocin (STZ). The characteristics of DCM were evaluated by cardiac ultrasonography, serum detection, and histopathological staining. The results suggested that CVB-D could significantly alleviate the cardiac pathology of DCM. Then, we explored the mechanism of CVB-D on primary neonatal rat cardiomyocyte (PNRCM) injury with high glucose (HG) in vitro to simulate the physiological environment of DCM. Preincubation with CVB-D could significantly increase cell viability, attenuate cytopathological changes and inhibit the expression levels of pyroptosis-related proteins. Further research found that the myocardial improvement effect of CVB-D was related to its inhibition of NLRP3 expression. In conclusion, our data suggest that CVB-D can ameliorate DCM by inhibiting cardiomyocyte pyroptosis via NLRP3, providing a novel molecular target for CVB-D clinical application.

Cyclovirobuxine D, a cardiovascular drug from traditional Chinese medicine, alleviates inflammatory and neuropathic pain mainly via inhibition of voltage-gated Cav3.2 channels.

Cyclovirobuxine D (CVB-D), the main active constituent of traditional Chinese medicine Buxus microphylla, was developed as a safe and effective cardiovascular drug in China. B. microphylla has also been used to relieve various pain symptoms for centuries. In this study, we examined and uncovered strong and persistent analgesic effects of cyclovirobuxine D against several mouse models of pain, including carrageenan- and CFA-induced inflammatory pain and paclitaxel-mediated neuropathic hypersensitivity. Cyclovirobuxine D shows comparable analgesic effects by intraplantar or intraperitoneal administration. Cyclovirobuxine D potently inhibits voltage-gated Cav2.2 and Cav3.2 channels but has negligible effects on a diverse group of nociceptive ion channels distributed in primary afferent neurons, including Nav1.7, Nav1.8, TRPV1, TPRA1, TRPM8, ASIC3, P2X2 and P2X4. Moreover, inhibition of Cav3.2, rather than Cav2.2, plays a dominant role in attenuating the excitability of isolated dorsal root ganglion neurons and pain relieving effects of cyclovirobuxine D. Our work reveals that a currently in-use cardiovascular drug has strong analgesic effects mainly via blockade of Cav3.2 and provides a compelling rationale and foundation for conducting clinical studies to repurpose cyclovirobuxine D in pain management.

Cyclovirobuxine D Induced-Mitophagy through the p65/BNIP3/LC3 Axis Potentiates Its Apoptosis-Inducing Effects in Lung Cancer Cells.

Mitophagy plays a pro-survival or pro-death role that is cellular-context- and stress-condition-dependent. In this study, we revealed that cyclovirobuxine D (CVB-D), a natural compound derived from Buxus microphylla, was able to provoke mitophagy in lung cancer cells. CVB-D-induced mitophagy potentiates apoptosis by promoting mitochondrial dysfunction. Mechanistically, CVB-D initiates mitophagy by enhancing the expression of the mitophagy receptor BNIP3 and strengthening its interaction with LC3 to provoke mitophagy. Our results further showed that p65, a transcriptional suppressor of BNIP3, is downregulated upon CVB-D treatment. The ectopic expression of p65 inhibits BNIP3 expression, while its knockdown significantly abolishes its transcriptional repression on BNIP3 upon CVB-D treatment. Importantly, nude mice bearing subcutaneous xenograft tumors presented retarded growth upon CVB-D treatment. Overall, we demonstrated that CVB-D treatment can provoke mitophagy and further revealed that the p65/BNIP3/LC3 axis is one potential mechanism involved in CVB-D-induced mitophagy in lung cancer cells, thus providing an effective antitumor therapeutic strategy for the treatment of lung cancer patients.

Cyclovirobuxine D Induces Apoptosis and Mitochondrial Damage in Glioblastoma Cells Through ROS-Mediated Mitochondrial Translocation of Cofilin.

BACKGROUND: Cyclovirobuxine D (CVBD), a steroidal alkaloid, has multiple pharmacological activities, including anti-cancer activity. However, the anti-cancer effect of CVBD on glioblastoma (GBM) has seldom been investigated. This study explores the activity of CVBD in inducing apoptosis of GBM cells, and examines the related mechanism in depth. METHODS: GBM cell lines (T98G, U251) and normal human astrocytes (HA) were treated with CVBD. Cell viability was examined by CCK-8 assay, and cell proliferation was evaluated by cell colony formation counts. Apoptosis and mitochondrial superoxide were measured by flow cytometry. All protein expression levels were determined by Western blotting. JC-1 and CM-H2DCFDA probes were used to evaluate the mitochondrial membrane potential (MMP) change and intracellular ROS generation, respectively. The cell ultrastructure was observed by transmission electron microscope (TEM). Colocalization of cofilin and mitochondria were determined by immunofluorescence assay. RESULTS: CVBD showed a greater anti-proliferation effect on the GBM cell lines, T98G and U251, than normal human astrocytes in dose- and time-dependent manners. CVBD induced apoptosis and mitochondrial damage in GBM cells. We found that CVBD led to mitochondrial translocation of cofilin. Knockdown of cofilin attenuated CVBD-induced apoptosis and mitochondrial damage. Additionally, the generation of ROS and mitochondrial superoxide was also induced by CVBD in a dose-dependent manner. N-acetyl-L-cysteine (NAC) and mitoquinone (MitoQ) pre-treatment reverted CVBD-induced apoptosis and mitochondrial damage. MitoQ pretreatment was able to block the mitochondrial translocation of cofilin caused by CVBD. CONCLUSIONS: Our data revealed that CVBD induced apoptosis and mitochondrial damage in GBM cells. The underlying mechanism is related to mitochondrial translocation of cofilin caused by mitochondrial oxidant stress.

Cyclovirobuxine D inhibits dengue virus replication by impeding the complete autophagy in a cholesterol-dependent manner.

Dengue virus (DENV) is the most common mosquito-borne flavivirus, and it affects millions of people globally every year. Currently, there are no approved drugs for the treatment of dengue infection. By screening a natural product library, we identified a novel compound, cyclovirobuxine D (Cvb D), that displays anti-DENV activity. Cvb D inhibits DENV replication in vitro in a dose-dependent manner and protects suckling mice against lethal DENV infection. Mechanistically, Cvb D regulates the expression of genes related to the cellular cholesterol pathway. As a result, Cvb D increases cellular cholesterol synthesis and accumulation, activates mTOR, and inhibits viral-dependent autophagy. Cvb D does not suppress autophagy initiation but impedes the nuclear translocation of the lysosome transcription factor TFEB. In addition, Cvb D restricts the replication of other positive-strand RNA viruses such as Zika virus and Coxsackievirus B3. We speculate that Cvb D could be a broad-spectrum antiviral drug candidate for use against positive-strand RNA viruses that require autophagy for optimal replication.

Cyclovirobuxine D ameliorates aldosterone-induced primary neonatal rat cardiac myocyte injury via Ca / 中国药理学通报

Aim To investigate the protective effect of cyclovirobuxine D(CVB-D) on aldosterone (ALD)-induced primary neonatal rat cardiac myocytes (PNRC-Ms) injury and the possible mechanism. Methods PNRCMs were extracted by trypsin, and the PNRCMs injury model was established by ALD (10 μmol · L

Cyclovirobuxine D inhibits colorectal cancer tumorigenesis via the CTHRC1­AKT/ERK­Snail signaling pathway.

Cyclovirobuxine D (CVB­D) is an alkaloid, which is mainly derived from Buxus microphylla. It has been reported that CVB­D has positive effects on breast cancer, gastric cancer and other malignant tumors. However, to the best of our knowledge, there are no reports regarding the effects of CVB­D on colorectal cancer (CRC). The purpose of the present study was to determine the anticancer effects of CVB­D and further elucidate its molecular mechanism(s). DLD­1 and LoVo cell lines were selected to evaluate the antitumor effect of CVB­D. Cytotoxicity, viability and proliferation were evaluated by the MTT and colony formation assays. Flow cytometry was used to detect the effects on apoptosis and the cell cycle in CVB­D­treated CRC cells. The migration and invasion abilities of CRC cells were examined by wound healing and Transwell assays. In addition, RNA sequencing, bioinformatics analysis and western blotting were performed to investigate the target of drug action and clarify the molecular mechanisms. A xenograft model was established using nude mice, and ultrasound was employed to assess the preclinical therapeutic effects of CVB­D in vivo. It was identified that CVB­D inhibited the proliferation, migration, stemness, angiogenesis and epithelial­mesenchymal transition of CRC cells, and induced apoptosis and S­phase arrest. In addition, CVB­D significantly inhibited the growth of xenografts. It is notable that CVB­D exerted anticancer effects in CRC cells partly by targeting collagen triple helix repeat containing 1 (CTHRC1), which may be upstream of the AKT and ERK pathways. CVB­D exerted anticancer effects through the CTHRC1­AKT/ERK­Snail signaling pathway. Targeted therapy combining CTHRC1 with CVB­D may offer a promising novel therapeutic approach for CRC treatment.

Cyclovirobuxine D inhibits cell proliferation and migration and induces apoptosis in human glioblastoma multiforme and low­grade glioma.

Gliomas are the most common neoplasm of the human central nervous system. Glioblastoma multiforme (GBM) is one of the most serious types of gliomas. Although considerable progress has been made in the development of cancer therapeutic agents, several antineoplastic drugs fail to penetrate the blood­brain barrier (BBB), resulting in a low survival rate of glioma patients. Recent studies have revealed that the traditional Chinese medicine Buxus microphylla contains the main active component Cyclovirobuxine D (CVB­D), which can cross the BBB with a novel delivery system. However, it remains unclear whether CVB­D exerts anticancer effects against GBM and low­grade glioma (LGG). The aim of the present study was to explore the feasibility of CVB­D as a new effective agent in the treatment of GBM and LGG. The ability of CVB­D to inhibit GBM and LGG cell proliferation was detected by CCK8 assay. Flow cytometry was used to detect cell cycle progression and apoptosis induction by Annexin V­FITC/PI assay. The expression levels of the apoptosis­associated proteins, namely cleaved caspase­3 and Bax/Bcl­2, were detected by western blot analysis. The mitochondrial membrane potential (ΔΨm) was detected by Rh123 dyed fluorescence micrograph. Hoechst staining was used to observe the morphological characteristics of the apoptotic cells. The scratch test was used to evaluate the migration of GBM and LGG cells. The results indicated that CVB­D reduced cell viability of T98G and Hs683 cells. Flow cytometry demonstrated that CVB­D­treated cells were arrested at the S phase of their cell cycle. The expression levels of the apoptosis­associated proteins were increased in CVB­D­treated cells. Rh123 and Hoechst staining indicated morphological changes and mitochondrial membrane potential changes of the cells undergoing apoptosis. The data confirmed that CVB­D inhibited cell proliferation by arresting the cell cycle of GBM and LLG cells and that it promoted the induction of cell apoptosis by altering the mitochondrial membrane potential. The findings of the present study indicate the potential value of CVB­D in the treatment of glioma.

Cyclovirobuxine D Exerts Anticancer Effects by Suppressing the EGFR-FAK-AKT/ERK1/2-Slug Signaling Pathway in Human Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC), the sixth most common malignancy worldwide, is characterized by a dismal prognosis due to high recurrence and metastasis rates. Thus, the need for the development of novel chemotherapeutic drugs is urgent. Cyclovirobuxine D (CVB-D), a steroidal alkaloid extracted from Buxus microphylla that has been extensively used to relieve the symptoms of cardiovascular diseases, has shown promising antineoplastic effects in recent studies. However, the therapeutic effects and underlying mechanisms of CVB-D on HCC remain largely unelucidated. This study experimentally indicated that CVB-D can repress HCC cell proliferation by arresting the cell cycle in G2 phase and can facilitate apoptosis. In addition, the migratory and invasive capabilities of HCC cells were noticeably attenuated by a nonlethal dose of CVB-D, and this attenuation was correlated with the inhibition of epithelial-mesenchymal transition (EMT). Moreover, in vivo, CVB-D displayed excellent anticancer effects in HCC tumor-bearing nude mice. Regarding the molecular mechanisms of CVB-D activity, decreased Slug expression was determined to be associated with the aforementioned anti-HCC functions of this extract, which might be regulated by epidermal growth factor receptor (EGFR) through the focal adhesion kinase (FAK)-associated PI3K/AKT and MEK/ERK1/2 signaling pathways. Collectively, our results revealed the suppressive effects of CVB-D on progressive behaviors of HCC, including proliferation, migration, invasion, and EMT, in addition to its outstanding proapoptotic effects, which were correlated with the inhibition of the EGFR-FAK-AKT/ERK1/2-Slug signaling pathway. These discoveries provide an experimental and theoretical foundation for the use of CVB-D as a promising candidate for HCC therapy.

JLX001 Ameliorates Ischemia/Reperfusion Injury by Reducing Neuronal Apoptosis via Down-Regulating JNK Signaling Pathway.

JLX001, a novel compound with similar structure with cyclovirobuxine D (CVB-D), has been proved to exert therapeutical effects on permanent focal cerebral ischemia. However, the protective effects of JLX001 on cerebral ischemia/reperfusion (I/R) injury and its anti-apoptotic effects have not been reported. We investigated the efficacy of JLX001 in two pharmacodynamic tests (pre-treatment test and post-treatment) with rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). The pharmacodynamic tests demonstrated that JLX001 ameliorated I/R injury by reducing infarct sizes and brain edema. The results of Morris water maze, neurological scores, cylinder test and posture reflex test implied that JLX001 improved the learning, memory and motor ability after MCAO/R in the long term. Anti-apoptotic effects of JLX001 and its regulation of cytosolic c-Jun N-terminal Kinases (JNKs) signal pathway were confirmed in vivo by co-immunofluorescence staining and western immunoblotting. Furthermore, primary cortical neuron cultures were prepared and exposed to oxygen glucose deprivation/reoxygenation (OGD/R) for in vitro studies. Cytotoxicity test and mitochondrial membrane potential (MMP) test showed that JLX001 enhanced cell survival rate and maintained MMP. Flow cytometry and TdT-mediated dUTP-X nick end labeling (TUNEL) staining demonstrated the anti-apoptotic effects of JLX001 in vitro. Likewise, JLX001 regulated JNK signal pathway in vivo, which was also confirmed by western immunoblotting. Collectively, this study presents the first evidence that JLX001 exerted protective effects against I/R injury by reducing neuronal apoptosis via down-regulating JNK signaling pathway.

JLX001 Modulated the Inflammatory Reaction and Oxidative Stress in pMCAO Rats via Inhibiting the TLR2/4-NF-κB Signaling Pathway.

Inflammatory reactions and oxidative stress play critical roles in cerebral ischemic injuries. Microglia are activated after ischemic injury. Activated microglia produce neurotoxic proinflammatory factors and reactive oxygen species (ROS), which have been demonstrated closely related TLR2/4-NF-κB signal pathways. This study was to evaluate the effect of JLX001 against ischemic injury and investigate the mechanisms. The permanent middle cerebral artery occlusion (pMCAO) model was employed in rats. The neurobehavioral score, brain infarction rate, brain water content, pathological changes, immunohistochemical staining, biochemical index (T-AOC, SOD, and MDA), proinflammatory factors (IL-1ß, TNF-α, and NO), expression of TLR2/4 and nuclear translocation of NF-κB p65 were determined. To explore probable underlying mechanism of the neuroprotective effect of JLX001, BV-2 cells were exposed to in oxygen-glucose deprivation (OGD) for 4 h to mimic ischemic injury in vitro. The result showed that JLX001 significantly decreased neurological deficit score, infarct size, and brain edema, attenuated pathological changes, inhibited the activation of microglia, improved the process of oxidative stress, reduced the release of proinflammatory cytokines and downregulated TLR2/4-NF-κB signal pathway. Moreover, OGD reduced BV2 cell viability, induced oxidative damage, increased the release of proinflammatory factors and activated TLR2/4-NF-κB signal pathway, which was significantly reversed by the intervention of JLX001. This study demonstrates that JLX001 is effective in protecting the brain from ischemic injury, which may be mediated by regulating oxidative stress, inflammation and inhibiting TLR2/4-NFκB signal pathway.

Qualitative and quantitative analysis of cyclovirobuxine D and related substances by HPLC-CAD in the active pharmaceutical ingredient of Huangyangning tablets / 药学学报

We have developed a new method using HPLC-CAD (charged aerosol detector) for the quantitative analysis of cyclovirobuxine D and related substances in the API of Huangyangning tablets. The related substances were further studied by HPLC-Q-Exactive coupled with hybrid quadrupole-orbitrap mass spectrometry. A HILIC column of XBridge Amide (4.6 mm×250 mm, 5 μm) was used, and the mobile phase was composed of acetonitrile and 100 mmol·L-1 ammonium formate (85∶15), which was adjusted to pH 2.8 with formic acid. Isocratic mode elution was adopted at a flow rate of 1.1 mL·min-1. The column temperature was set at 30 ℃. For CAD, the temperature of atomization and gas pressure were respectively set at 35 ℃ and 62.2 psi. This method detected and quantified five related substances to cyclovirobuxine D. The results showed that the LOD and LOQ of cyclovirobuxine D was 12.588 ng and 28.323 ng, respectively with an average recovery of 95.74% (RSD = 1.79%, n = 6). The content of cyclovirobuxine D in 12 batches of API samples provided by three manufacturers was from 79.94% to 88.49%, with an average value of 82.20%. The total content of the five related substances was from 15.99% to 22.15% with an average value of 20.10%, using an external standard method with cyclovirobuxine D as the reference and according to the CAD uniform response to non-volatile substances. The newly developed HPLC-CAD method has advantages in terms of the comprehensiveness of signals from Buxus alkaloids without UV absorption and with high sensitivity to its trace-related substances; the method yields good separation between the components and is compatible with mass spectrometry. It is applicable for the accurate quantitative analysis of main components and related substances in the API of Huangyangning tablets.

Therapeutic effects of JLX001 on cerebral ischemia through inhibiting platelet activation and thrombus formation in rats.

(3ß,5α,16α,20S)-4,4,14-trimethyl-3,20-bis(methylamino)-9,19-cyclopregnan-16-ol-dihydrochloride (JLX001), a derivative of cyclovirobuxine D (CVB-D), is a novel compound from synthesis. This study aims to confirm the therapeutic effect of JLX001 on cerebral ischemia and researchits antiplatelet and antithrombosis activities via thromboxane (TXA2)/phospholipase C-ß-3(PLCß3)/protein kinase C (PKC) pathway suppression. The therapeutic effects of JLX001 was evaluated by infarct sizes, brain edema and neurological scores in Sprague-Dawley (SD) rats with middle cerebral artery occlusion (MCAO). Brain TXA2 and prostacyclin (PGI2) were measured by enzyme-linked immunosorbentassay (ELISA). P-PLCß3and activated PKC were detected by immunohistochemical method. Adenosine diphosphate (ADP) or 9, 11-dieoxy-11α, 9α-epoxymethanoeprostaglandin F2α (U46619) was used as platelet agonist in the in vivo and in vitro platelet aggregation experiments. Clotting time and bleeding time were determined. Besides, two whole-animal experiments including arteriovenous shunt thrombosis and pulmonary thromboembolism model were conducted. Results showed that JLX001 treatment markedly alleviated cerebral infarcts, edema, and neurological scores in permanent middle cerebral artery occlusion (pMCAO) rats. Brain TXA2 level, p-PLCß3and activated PKC were decreased, while PGI2level had no significant change. Besides, JLX001 inhibited platelet aggregation induced by ADP or U46619 and exhibited anti-coagulation effects with a minor bleeding risk. In the two whole-animal experiments, JLX001 inhibited thrombus formation. In summary, JLX001 attenuates cerebral ischemia injury and the underlying mechanisms relate to inhibiting platelet activation and thrombus formation via TXA2/PLCß3/PKC pathway suppression.

Ketoconazole promotes in situ intestinal absorption of cyclovirobuxine D hydroxypropyl-β-cyclodextrin inclusion complex in rats / 第二军医大学学报

Objective To study the in situ intestinal absorption characteristics of cyclovirobuxine D (CB) hydroxypropyl-β-cyclodextrin inclusion complex (CBHD) in rats, and to explore the effect of cytochrome P450 inhibitor ketoconazole (KET) on CB and CBHD in situ intestinal absorption. Methods Twenty-four male rats were randomized into CB, CBHD, KET+CB and KET+CBHD groups, with 6 rats in each group. In situ intestinal absorption was adopted in a rat model. One-way intestinal perfusion model was employed to investigate the absorption of CB and CBHD in the intestinal segments of rats and the effects of KET on CB and CBHD absorption. The concentration of CB was determined by highperformance liquid chromatography with fluorescence detector (HPLC/FLD; Lichrospher C18 column [250 mm×4.6 mm, 5 μm]). The mobile phase was methanol-water with volume ratio being 85: 15. The excitation wavelength was set at 231 nm, and emission wavelength was set at 385 nm. The column temperature was 25 °C, and flow rate was 1.0 mL/min. The injection volume was 20 μL. Results The specificity of HPLC/FLD method was good and the standard curve equation was A=106.7 C+41.861 (R2=0.999 08) based on the linear regression of CB concentration (C) with CB peak area (A), indicating that the CB mass concentration was linear in the range of 0.5 to 20.0 μg/mL. The intra-day precision of the 1.0, 5.0 and 10.0 μg/mL samples was 2.25%, 2.44% and 3.04%, and the inter-day precision was 4.22%, 2.00% and 2.50%, respectively. The precision was good and the method was in accordance with the requirements of methodology. The recovery rates of the 1.0, 5.0 and 10.0 μg/mL samples were 99.08%, 98.24% and 97.25%, respectively, which were also in accordance with the requirements of methodology. The intestinal absorption rate constant (Ka) values of CBHD with KET were 4.18, 5.05, 1.91 and 2.85 times those of CB, and the effective permeability (Peff) values were 4.92, 5.98, 2.19 and 3.24 times those of CB in the duodenum, jejunum, ileum and colon, respectively (all P<0.05). Conclusion KET can improve the intestinal absorption of CB and CBHD in rats.

Design and optimization of self-nanoemulsifying drug delivery systems for improved bioavailability of cyclovirobuxine D.

BACKGROUND: The main purpose of this research was to design a self-nanoemulsifying drug delivery system (SNEDDS) for improving the bioavailability of cyclovirobuxine D as a poorly water-soluble drug. MATERIALS AND METHODS: Solubility trials, emulsifying studies, and pseudo-ternary phase diagrams were used to screen the SNEDDS formulations. The optimized drug-loaded SNEDDS was prepared at a mass ratio of 3:24:38:38 for cyclovirobuxine D, oleic acid, Solutol SH15, and propylene glycol, respectively. The optimized formulation was characterized in terms of physicochemical and pharmacokinetic parameters compared with marketed cyclovirobuxine D tablets. RESULTS: The optimized cyclovirobuxine-D-loaded SNEDDS was spontaneously dispersed to form a nanoemulsion with a globule size of 64.80±3.58 nm, which exhibited significant improvement of drug solubility, rapid absorption rate, and enhanced area under the curve, together with increased permeation and decreased efflux. Fortunately, there was a nonsignificant cytotoxic effect toward Caco-2 cells. The relative bioavailability of SNEDDS was 200.22% in comparison with market tablets, in rabbits. CONCLUSION: SNEDDS could be a potential candidate for an oral dosage form of cyclovirobuxine D with improved bioavailability.