Isocorydine inhibits cell proliferation in hepatocellular carcinoma cell lines by inducing G2/m cell cycle arrest and apoptosis

Natural aporphine alkaloids: A comprehensive review of phytochemistry, pharmacokinetics, anticancer activities, and clinical application

BACKGROUND

Cancer is the most common cause of death and is still a serious public health problem. Alkaloids, a class of bioactive compounds widely diffused in plants, especially Chinese herbs, are used as functional ingredients, precursors, and lead compounds in food and clinical applications. Among them, aporphine alkaloids (AAs), as an important class of isoquinoline alkaloids, exert a strong anticancer effect on multiple cancer types.

AIM OF REVIEW

This review aims to comprehensively summarize the phytochemistry, pharmacokinetics, and bioavailability of seven subtypes of AAs and their derivatives from various plants and highlight their anticancer bioactivities and mechanisms of action. Key Scientific Concepts of Review. The chemical structures and botanical diversity of AAs are elucidated, and promising results are highlighted regarding the potent anticancer activities of AAs and their derivatives, contributing to their pharmacological benefits. This work provides a better understanding of AAs and combinational anticancer therapies involving them, thereby improving the development of functional food containing plant-derived AA and the clinical application of AAs.

A comprehensive review of phytoconstituents in liver cancer prevention and treatment: targeting insights into molecular signaling pathways

Primary liver cancer is a type of cancer that develops in the liver. Hepatocellular carcinoma is a primary liver cancer that usually affects adults. Liver cancer is a fatal global condition that affects millions of people worldwide. Despite advances in technology, the mortality rate remains alarming. There is growing interest in researching alternative medicines to prevent or reduce the effects of liver cancer. Recent studies have shown growing interest in herbal products, nutraceuticals, and Chinese medicines as potential treatments for liver cancer. These substances contain unique bioactive compounds with anticancer properties. The causes of liver cancer and potential treatments are discussed in this review. This study reviews natural compounds, such as curcumin, resveratrol, green tea catechins, grape seed extracts, vitamin D, and selenium. Preclinical and clinical studies have shown that these medications reduce the risk of liver cancer through their antiviral, anti-inflammatory, antioxidant, anti-angiogenic, and antimetastatic properties. This article discusses the therapeutic properties of natural products, nutraceuticals, and Chinese compounds for the prevention and treatment of liver cancer.

Natural alkaloids from Dicranostigma leptopodum (Maxim.) Fedde and their G5. NHAc-PBA dendrimer-alkaloid complexes for targeting chemotherapy in breast cancer MCF-7 cells

Herein, we isolated five natural alkaloids, iso-corydine (iso-CORY), corydine (CORY), sanguinarine (SAN), chelerythrine (CHE) and magnoflorine (MAG), from traditional medicinal herb Dicranostigma leptopodum (Maxim.) Fedde (whole herb) and elucidated their structures. Then we synthesised G5. NHAc-PBA as targeting dendrimer platform to encapsulate the alkaloids into G5. NHAc-PBA-alkaloid complexes, which demonstrated alkaloid-dependent positive zeta potential and hydrodynamic particle size. G5. NHAc-PBA-alkaloid complexes demonstrated obvious breast cancer MCF-7 cell targeting effect. Among the G5. NHAc-PBA-alkaloid complexes, G5.NHAc-PBA-CHE (IC50=13.66 μM) demonstrated the highest MCF-7 cell inhibition capability and G5.NHAc-PBA-MAG (IC50=24.63 μM) had equivalent inhibitory effects on cell proliferation that comparable to the level of free MAG (IC50=23.74 μM), which made them the potential breast cancer targeting formulation for chemotherapeutic application. This work successfully demonstrated a pharmaceutical research model of 'natural bioactive product isolation-drug formulation preparation-breast cancer cell targeting inhibition'.

Anticancer Activity and Molecular Targets of Piper cernuum Substances in Oral Squamous Cell Carcinoma Models

Oral squamous cell carcinoma (OSCC) is a worldwide public health problem, with high morbidity and mortality rates. The development of new drugs to treat OSCC is paramount. Piper plant species have shown many biological activities. In the present study, we show that dichloromethane partition of Piper cernuum (PCLd) is nontoxic in chronic treatment in mice, reduces the amount of atypia in tongues of chemically induced OSCC, and significantly increases animal survival. To identify the main active compounds, chromatographic purification of PCLd was performed, where fractions 09.07 and 14.05 were the most active and selective. These fractions promoted cell death by apoptosis characterized by phosphatidyl serine exposition, DNA fragmentation, and activation of effector caspase-3/7 and were nonhemolytic. LC-DAD-MS/MS analysis did not propose matching spectra for the 09.07 fraction, suggesting compounds not yet known. However, aporphine alkaloids were annotated in fraction 14.05, which are being described for the first time in P. cernuum and corroborate the observed cytotoxic activity. Putative molecular targets were determined for these alkaloids, in silico, where the androgen receptor (AR), CHK1, CK2, DYRK1A, EHMT2, LXRβ, and VEGFR2 were the most relevant. The results obtained from P. cernuum fractions point to promising compounds as new preclinical anticancer candidates.

Isocorydine Ameliorates IL-6 Expression in Bone Marrow-Derived Macrophages and Acute Lung Injury Induced by Lipopolysaccharide

Isocorydine (ICD) is a type of isoquinoline alkaloid originating from Corydalis edulis, which has been used to relieve spasm, dilate blood vessels, and treat malaria as well as hypoxia in clinic. However, its effect on inflammation and underlying mechanisms remains unclear. The aim of our study was to determine the potential effects and mechanisms of ICD on pro-inflammatory interleukin-6 (IL-6) expression in bone marrow-derived macrophages (BMDMs) and acute lung injury mouse model. A mouse model of acute lung injury was established by intraperitoneal injection of LPS and treated with different doses of ICD. The body weight and food intake of mice were monitored to determine the toxicity of ICD. The tissue samples of lung, spleen and blood were taken to assess the pathological symptoms of acute lung injury and the expression levels of IL-6. Further, BMDMs isolated from C57BL/6 mice were cultured in vitro and treated with granulocyte-macrophage colony-stimulating factor (GM-CSF), LPS and different doses of ICD. CCK-8 assay and flow cytometry were performed to assess the viability of BMDMs. The expression of IL-6 was detected by RT-PCR and ELISA. RNA-seq was carried out to detect the differential expression genes of ICD-treated BMDMs. Western blotting was used to detect the change in MAPK and NF-κB signaling pathways. Our findings show that ICD ameliorates IL-6 expression and attenuates phosphorylation of p65 and JNK in BMDMs, and can protect mice from acute lung injury.

Garmultin-A Incites Apoptosis in CB3 Cells Through miR-17-5p by Attenuating Poly (ADP-Ribose) Polymerase-1

Background

Leukemia accounts for a large number of deaths, worldwide, every year. Treating this ailment is always a challenging job. Recently, oncogenic miRNA leading to apoptosis are highly promising targets of many natural products. In this study, Garmultin-A (GA), isolated from the bark of Garcinia multiflora, was elucidated for its anti-leukemic effect in CB3 cells.

Methods

The effect of the compound on CB3 cell viability was detected by MTT assay and apoptosis by FITC Annexin V/PI and Hochest 33258 staining. The western blot analysis assessed the BAX, BCL2, cMYC, pERK, and PARP-1 protein levels. Autodock analysis predicted the ligand–protein interactions. q-RT-PCR quantified the miR-17-5p expression. Luciferase assay confirmed the interaction between PARP-1 and miR-17-5p.

Results

We uncover that GA leads to apoptosis by inducing overexpression of miR-17-5p and significantly downregulate PARP-1 protein levels in CB3 cells. The overexpression of miR-17-5p promotes apoptosis, and the miR-17-5p antagomirs restore GA-triggered apoptosis. Notably, we disclose that PARP-1 is a direct target of miR-17-5p. Increased pro-apoptotic and reduced anti-apoptosis protein levels were also observed in GA-treated CB3 cells.

Conclusion

These results provide critical insights that GA could induce apoptosis in CB3 cells through targeting miR-17-5p by attenuating PARP-1. Thus, GA could act as a novel therapeutic agent for erythroleukemia.

Recent Progress in Understanding the Action of Natural Compounds at Novel Therapeutic Drug Targets for the Treatment of Liver Cancer

Liver cancer is the third most common cause of cancer-related death following lung and stomach cancers. As a highly lethal disease, liver cancer is diagnosed frequently in less developed countries. Natural compounds extracted from herbs, animals and natural materials have been adopted by traditional Chinese medicine (TCM) practices and reported to be effective in the development of new medications for the treatment of diseases. It is important to focus on the mechanisms of action of natural compounds against hepatocellular carcinoma (HCC), particularly in terms of cell cycle regulation, apoptosis induction, autophagy mediation and cell migration and invasion. In this review, we characterize novel representative natural compounds according to their pharmacologic effects based on recently published studies. The aim of this review is to summarize and explore novel therapeutic drug targets of natural compounds, which could accelerate the discovery of new anticancer drugs.

A new N-oxide benzylisoquinoline alkaloid isolated from the leaves of atemoya (Annona cherimola × Annona squamosa)

Phytochemical investigation of the atemoya aerial parts was carried out by LC-MS-IT and cytotoxic activities were evaluated as well. These results led to the identification of a new N-oxide alkaloid (dehydroanomuricine-N-oxide) and eight other alkaloids: scoulerine, reticuline, isocorydine, norisocorydine, asimilobine, nornuciferine, anonaine, and liriodenine. The new alkaloid dehydroanomuricine-N-oxide and anomuricine were also isolated. The structures of these compounds were determined by spectroscopic and spectrometric techniques. The cytotoxic capacity of crude methanolic extract and the alkaloidal fraction were evaluated, showing moderate cytotoxicity. The isolation and identification of these alkaloids are an important contribution to the chemotaxonomy of the genus Annona and the Annonaceae family.

Effects of 8-Amino-Isocorydine, a Derivative of Isocorydine, on Gastric Carcinoma Cell Proliferation and Apoptosis

Background

Isocorydine (ICD) has anticancer effects; however, its suboptimal bioactivity has driven the production of ICD derivatives, including 8-amino-isocorydine (8-NICD).

Objective

This study explored the antitumor effects of 8-NICD on a variety of tumor cell lines to detect tumors sensitive to 8-NICD and investigated the mechanisms by which it suppresses tumor cell growth.

Methods

Human gastric carcinoma (GC) cells (MGC-803) were used to evaluate the effects of 8-NICD on cell proliferation and apoptosis. The in vivo action of 8-NICD in a nude mouse xenograft model was also investigated. The antioxidant activity of 8-NICD was evaluated using a 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay.

Results

8-NICD exerted significant antitumor activity against several tumor cell lines with IC₅₀ between 8.0 and 142.8 µM and was not toxic to healthy fibroblasts and epithelial cells at concentrations up to 100 µM. Moreover, 8-NICD strongly inhibited the proliferation of MGC803 cells without causing toxicity to human umbilical vein endothelial cells with a selectivity index of 19.2 and arrested MGC803 cells in the S phase. Further, the percentages of apoptotic MGC-803 and BGC823 cells increased in a concentration-dependent manner, and the expression of apoptosis regulator Bax increased, whereas that of Bcl-2 decreased in response to 8-NICD treatment. Further, 8-NICD significantly suppressed MGC-803 tumor growth in nude mice. In addition, 8-NICD was a potent scavenger of radicles in a 1,1-diphenyl-2-picrylhydrazyl (IC₅₀ = 11.12 µM) antioxidant assay.

Conclusions

These results suggest that 8-NICD exerts significant antitumor effects on GC cells by inducing apoptosis and cell cycle arrest and is a promising candidate anti-GC drug. The particularly high sensitivity of MGC803 cells suggest that the potential of 8-NICD to treat GC should be further explored. (Curr Ther Res Clin Exp. 2021; 82:XXX–XXX)

Cytotoxic Activity and Initiation of Apoptosis via Intrinsic Pathway in Jurkat Cells by Leaf Extract of Zanthoxylum rhetsa DC

BACKGROUND

Newer drugs are in demand for leukemia treatment that specifically targets tumor cells without affecting normal cells. Potent cytotoxic activities have been reported from various parts of Zanthoxylum rhetsa. Thus, the present study was conducted to evaluate antileukemic potential of leaf extract of Z. rhetsa along with probable mechanism of cytotoxicity. Materials and Methods: The antiproliferative activity of the extract on leukemic cell lines was evaluated using sulforhodamine B assay. The changes in cell death profile, cell cycle, and expression levels of pro-apoptotic markers (p53, Bax, cytochrome C, caspase 3, and MMP) and antiapoptic marker (Bcl2) on Jurkat cell lines were studied using flow cytometer. Comparison of oxidative stress induced by extract on Jurkat cells and normal mouse fibroblast cells was done. DNA fragmentation was studied using gel electrophoresis. Results: The leaf extract showed concentration-dependent cytotoxicity against Jurkat cell lines majorly via apoptotic mechanism. It arrested cells at G0/G1 and S phase of cell cycle. Apoptosis was associated with increase in the expression of pro-apoptotic markers and decrease of anti-apoptotic markers. The treatment with extract selectively increased the oxidative stress in Jurkat cells and showed DNA fragmentation. Conclusion: The methanol extract of leaves of Z. rhetsa show selective cytotoxic activity on Jurkat cell lines and induced apoptosis via intrinsic pathway.

Isocorydine decrease gemcitabine-resistance by inhibiting epithelial-mesenchymal transition via STAT3 in pancreatic cancer cells

Gemcitabine is widely used as an anticancer chemotherapy drug for a variety of solid tumors, and it has become the standard treatment option for locally advanced and metastatic pancreatic cancer. However, pancreatic cancer cells develop resistance to gemcitabine after a few weeks of treatment, resulting in poor therapeutic effects. Isocorydine (ICD) is a typical natural aporphine alkaloid, and ICD and its derivatives inhibit the proliferation of many types of cancer cells in vitro. In this study, ICD was found to synergistically inhibit cell viability with gemcitabine in pancreatic cancer cells. A microarray analysis showed that ICD can inhibit the upregulation of STAT3 and EMT in pancreatic cancer cells induced by gemcitabine. STAT3 is closely related to tumor EMT, migration and invasion. After knocking down the expression of STAT3 in pancreatic cancer cells, the combination index (CI) of ICD and gemcitabine decreased. ICD can reverse the increase in the expression of EMT-related transcription factors and proteins caused by gemcitabine, thereby inhibiting the enhanced cell migration and invasion ability caused by gemcitabine. Finally, the synergistic treatment effect of the combination treatment of ICD and gemcitabine in pancreatic cancer cells was confirmed in established xenograft models.

Regulatory networks in mechanotransduction reveal key genes in promoting cancer cell stemness and proliferation

Tumor-repopulating cells (TRCs) are cancer stem cell (CSC)-like cells with highly tumorigenic and self-renewing abilities, which were selected from tumor cells in soft three-dimensional (3D) fibrin gels with unidentified mechanisms. Here we evaluated the transcriptome alteration during TRCs generation in 3D culture and revealed that a variety of molecules related with integrin/membrane and stemness were continuously altered by mechanical environment. Some key regulators such as MYC/STAT3/hsa-miR-199a-5p, were changed in the TRCs generation. They regulated membrane genes and the downstream mechanotransduction pathways such as Hippo/WNT/TGF-β/PI3K-AKT pathways, thus further affecting the expression of downstream cancer-related genes. By integrating networks for membrane proteins, the WNT pathway and cancer-related genes, we identified key molecules in the selection of TRCs, such as ATF4, SLC3A2, CCT3, and hsa-miR-199a-5p. Silencing ATF4 or CCT3 inhibited the selection and growth of TRCs whereas reduction of SLC3A2 or hsa-miR-199a-5p promoted TRCs growth. Further studies showed that CCT3 promoted cell proliferation and stemness in vitro, while its suppression inhibited TRCs-induced tumor formation. We also contemplated CCT3 as a stemness-related gene. Our findings provide insights in the mechanism of TRCs selection through transcriptome analysis.

Assessment of the cytotoxic effects of aporphine prototypes on head and neck cancer cells

Purpose Among alkaloids, abundant secondary metabolites in plants, aporphines constitute a class of compounds with interesting biological activities, including anticancer effects. The present study evaluated the anticancer activities of 14 substances, including four aporphine derivatives acquired through the biomonitoring of (±)-apomorphine hydrochloride total synthesis from 2-phenethylamine and 3,4-dimethoxybenzaldehyde against head and neck squamous cell carcinoma (HNSCC). Methods The cytotoxic effects of compounds against a panel of HNSCC cell lines were determined by PrestoBlue cell viability assay, while the genotoxicity of substances was evaluated by micronucleus test. Cell death was detected by flow cytometry (Annexin V/7AAD) and western blot analysis was used to detect the presence of cleaved Caspase-3 molecules. Results The aporphine and isoquinoline derivatives APO, C1, and A5 significantly reduced HNSCC cell viability and promoted DNA damages in these cells. Further, by activating the Caspase-3 pathway, these substances were able to induce apoptosis. Conclusion Our results revealed that APO, C1, and A5 exhibit cytotoxic effects in HNSCC cells. The mechanisms of action appear to be partly via the generation of DNA damages and apoptosis induction through Caspase-3 pathway activation. This study provides preclinical data that suggest a potential therapeutic role for APO, C1, and A5 against head and neck cancer cells.

MHY440, a Novel Topoisomerase Ι Inhibitor, Induces Cell Cycle Arrest and Apoptosis via a ROS-Dependent DNA Damage Signaling Pathway in AGS Human Gastric Cancer Cells

We investigated the antitumor activity and action mechanism of MHY440 in AGS human gastric cancer cells. MHY440 inhibited topoisomerase (Topo) Ι activity and was associated with a DNA damage response signaling pathway. It exhibited a stronger anti-proliferative effect on AGS cells relative to Hs27 human foreskin fibroblast cells, and this effect was both time- and concentration-dependent. MHY440 also increased cell arrest in the G2/M phase by decreasing cyclin B1, Cdc2, and Cdc25c, and upregulating p53 and p73. MHY440 induced AGS cell apoptosis through the upregulation of Fas-L, Fas, and Bax as well as the proteolysis of BH3 interacting-domain death agonist and poly(ADP-ribose) polymerase. It also contributed to the loss of mitochondrial membrane potential. The apoptotic cell death induced by MHY440 was inhibited by pretreatment with Z-VAD-FMK, a pan-caspase inhibitor, indicating that apoptosis was caspase-dependent. Moreover, the apoptotic effect of MHY440 was reactive oxygen species (ROS)-dependent, as evidenced by the inhibition of MHY440-induced PARP cleavage and ROS generation via N-acetylcysteine-induced ROS scavenging. Taken together, MHY440 showed anticancer effects by inhibiting Topo I, regulating the cell cycle, inducing apoptosis through caspase activation, and generating ROS, suggesting that MHY440 has considerable potential as a therapeutic agent for human gastric cancer.

PLAGL1 gene function during hepatoma cells proliferation

Hepatocellular carcinoma develops as a multistep process, in which cell cycle deregulation is a central feature, resulting in unscheduled proliferation. The PLAGL1 gene encodes a homonym zinc finger protein that is involved in cell-proliferation control. We determined the genomic profile and the transcription and expression level of PLAGL1, simultaneously with that of its molecular partners p53, PPARγ and p21, in cell-lines derived from patients with liver cancer, during in vitro cell growth. Our investigations revealed that genomic and epigenetic changes of PLAGL1 are also present in hepatoma cell-lines. Transcription of PLAGL1 in tumor cells is significantly lower than in normal fibroblasts, but no significant differences in terms of protein expression were detected between these two cell-types, indicating that there is not a direct relationship between the gene transcriptional activity and protein expression. RT-PCR analyses on normal fibroblasts, used as control, also showed that PLAGL1 and p53 genes transcription occurs as an apparent orchestrated process during normal cells proliferation, which gets disturbed in cancer cells. Furthermore, abnormal trafficking of the PLAGL1 protein may occur in hepatocarcinogenesis.

Design, synthesis, and anticancer properties of isocorydine derivatives

Isocorydine (ICD), an aporphine alkaloid, is widely distributed in nature. Its ability to target side population (SP) cells found in human hepatocellular carcinoma (HCC) makes it and its derivative 8-amino-isocorydine (NICD) promising chemotherapeutic agents for the treatment of HCC. To improve the anticancer activity of isocorydine derivatives, twenty derivatives of NICD were designed and synthesized through chemical structure modifications of the aromatic amino group at C-8. The anti-proliferative activities of all synthesized compounds against human hepatocellular (HepG2), cervical (HeLa), and gastric (MGC-803) cancer cell lines were evaluated using an MTT assay. The results showed that all the synthetic compounds had some tumor cell growth inhibitory activity. The compound COM33 (24) was the most active with IC₅₀ values under 10 μM (IC₅₀ for HepG2 = 7.51 µM; IC₅₀ for HeLa = 6.32 μM). FICD (12) and COM33 (24) were selected for further investigation of their in vitro and in vivo activities due to their relatively good antiproliferative properties. These two compounds significantly downregulated the expression of four key proteins (C-Myc, β-Catenin, CylinD1, and Ki67) in HepG2 cells. The tumor inhibition rate of COM33 (24) in vivo was 73.8% after a dose 100 mg/kg via intraperitoneal injection and the combined inhibition rate of COM33 (24) (50 mg/kg) with sorafenib (50 mg/kg) was 66.5%. The results indicated that these isocorydine derivatives could potentially be used as targeted chemotherapy agents or could be further developed in combination with conventional chemotherapy drugs to target cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT), the main therapeutic targets in HCC.

Epigenetic mediated zinc finger protein 671 downregulation promotes cell proliferation and tumorigenicity in nasopharyngeal carcinoma by inhibiting cell cycle arrest

Background

Epigenetic abnormalities play important roles in nasopharyngeal cancer (NPC), however, the epigenetic changes associated with abnormal cell proliferation remain unclear.

Methods

We detected epigenetic change of ZNF671 in NPC tissues and cell lines by bisulfite pyrosequencing. We evaluated zinc finger protein 671 (ZNF671) expression in NPC cell lines and clinical tissues using real-time PCR and western blotting. Then, we established NPC cell lines that stably overexpressed ZNF671 and knocked down ZNF671 expression to explore its function in NPC in vitro and in vivo. Additionally, we investigated the potential mechanism of ZNF671 by identifying the mitotic spindle and G2/M checkpoint pathways pathway downstream genes using gene set enrichment analysis, flow cytometry and western blotting.

Results

ZNF671 was hypermethylated in NPC tissues and cell lines. The mRNA and protein expression of ZNF671 was down-regulated in NPC tissues and cell lines and the mRNA expression could be upregulated after the demethylation agent 5-aza-2′-deoxycytidine treatment. Overexpression of ZNF671 suppressed NPC cell proliferation and colony formation in vitro; silencing ZNF671 using a siRNA had the opposite effects. Additionally, overexpression of ZNF671 reduced the tumorigenicity of NPC cells in xenograft model in vivo. The mechanism study determined that overexpressing ZNF671 induced S phase arrest in NPC cells by upregulating p21 and downregulating cyclin D1 and c-myc.

Conclusions

Epigenetic mediated zinc finger protein 671 downregulation promotes cell proliferation and enhances tumorigenicity by inhibiting cell cycle arrest in NPC, which may represent a novel potential therapeutic target.

Electronic supplementary material

The online version of this article (10.1186/s13046-017-0621-2) contains supplementary material, which is available to authorized users.

Identification of candidate genes involved in isoquinoline alkaloids biosynthesis in Dactylicapnos scandens by transcriptome analysis

Dactylicapnos scandens (D. Don) Hutch (Papaveraceae) is a well-known traditional Chinese herb used for treatment of hypertension, inflammation, bleeding and pain for centuries. Although the major bioactive components in this herb are considered as isoquinoline alkaloids (IQAs), little is known about molecular basis of their biosynthesis. Here, we carried out transcriptomic analysis of roots, leaves and stems of D. scandens, and obtained a total of 96,741 unigenes. Based on gene expression and phylogenetic relationship, we proposed the biosynthetic pathways of isocorydine, corydine, glaucine and sinomenine, and identified 67 unigenes encoding enzymes potentially involved in biosynthesis of IQAs in D. scandens. High performance liquid chromatography analysis demonstrated that while isocorydine is the most abundant IQA in D. scandens, the last O-methylation biosynthesis step remains unclear. Further enzyme activity assay, for the first time, characterized a gene encoding O- methyltransferase (DsOMT), which catalyzes O-methylation at C7 of (S)-corytuberine to form isocorydine. We also identified candidate transcription factor genes belonging to WRKY and bHLH families that may be involved in the regulation of IQAs biosynthesis. Taken together, we first provided valuable genetic information for D. scandens, shedding light on candidate genes involved in IQA biosynthesis, which will be critical for further gene functional characterization.

Derivate Isocorydine (d-ICD) Suppresses Migration and Invasion of Hepatocellular Carcinoma Cell by Downregulating ITGA1 Expression

In our previous studies, we found that isocorydine (ICD) could be a potential antitumor agent in hepatocellular carcinoma (HCC). Derivate isocorydine (d-ICD), a more effective antitumor agent, has been demonstrated to inhibit proliferation and drug resistance in HCC. In order to investigate the potential role of d-ICD on HCC cell migration and its possible mechanism, wound healing assay, trans-well invasion assay, western blot analysis, and qRT-PCR were performed to study the migration and invasion ability of HCC cells as well as relevant molecular alteration following d-ICD treatment. Results indicated that the migration and invasion ability of HCC cells were suppressed when cultured with d-ICD. Meanwhile, the expression level of ITGA1 was markedly reduced. Furthermore, we found that ITGA1 promotes HCC cell migration and invasion in vitro, and that ITGA1 can partly reverse the effect of d-ICD-induced migration and invasion suppression in HCC cells. In addition, dual luciferase reporter assay and chromatin immunoprecipitation assay were used to study the expression regulation of ITGA1, and found that E2F1 directly upregulates ITGA1 expression and d-ICD inhibits E2F1 expression. Taken together, these results reveal that d-ICD inhibits HCC cell migration and invasion may partly by downregulating E2F1/ITGA1 expression.

An isocorydine derivative (d-ICD) inhibits drug resistance by downregulating IGF2BP3 expression in hepatocellular carcinoma

In our previous studies, we reported that CD133⁺ cancer stem cells (CSCs) were chemoresistant in hepatocellular carcinoma (HCC) and that isocorydine treatment decreased the percentage of CD133⁺ CSCs. Here, we found that a derivative of isocorydine (d-ICD) inhibited HCC cell growth, particularly among the CD133⁺ subpopulation, and rendered HCC cells more sensitive to sorafenib treatment. d-ICD inhibited IGF2BP3 expression in a time-dependent manner, and IGF2BP3 expression negatively correlated with d-ICD-induced growth suppression. IGF2BP3 overexpression enriched the CD133⁺ CSC subpopulation in HCC, enhanced tumor sphere formation and suppressed the cytotoxic effects of sorafenib and doxorubicin. The expression of drug resistance-related genes, including ABCB1 and ABCG2, and the CSC marker CD133 expression was increased after IGF2BP3 overexpression. The significance of these observations was underscored by our findings that high IGF2BP3 expression predicted poor survival in a cohort of 236 patients with HCC and positively correlated with ABCG2 and CD133 expression in vivo. These results suggested that the d-ICD may inhibit HCC cells growth by IGF2BP3 decrease and that IGF2BP3 may serve as a therapeutic target for HCC.

Anti-cancer Activity of Osmanthus matsumuranus Extract by Inducing G2/M Arrest and Apoptosis in Human Hepatocellular Carcinoma Hep G2 Cells

BACKGROUND

Osmanthus matsumuranus, a species of Oleaceae, is found in East Asia and Southeast Asia. The bioactivities of O. matsumuranus have not yet been fully understood. Here, we studied on the molecular mechanisms underlying anti-cancer effect of ethanol extract of O. matsumuranus (EEOM).

METHODS

Inhibitory effect of EEOM on cell growth and proliferation was determined by WST assay in various cancer cells. To investigate the mechanisms of EEOM-mediated cytotoxicity, HepG2 cells were treated with various concentration of EEOM and analyzed the cell cycle arrest and apoptosis induction by flow cytometry, Western blot analysis, 4,6-diamidino-2-phenylindole (DAPI) staining and DNA fragmentation.

RESULTS

EEOM showed the cytotoxic activities in a dose-dependent manner in various cancer cell lines but not in normal cells, and HepG2 cells were most susceptible to EEOM-induced cytotoxicity. EEOM induced G2/M arrest in HepG2 cells associated with decreased expression of cyclin-dependent kinase 1 (CDK1), cyclin A and cylcin B, and increased expression of phospho-checkpoint kinase 2, p53 and CDK inhibitor p21. Immunofluorescence staining showed that EEOM-treated HepG2 increased doublet nuclei and condensed actin, resulting in cell rounding. Furthermore, EEOM-mediated apoptosis was determined by Annexin V staining, chromatin condensation and DNA fragmentation. EEOM caused upregulation of FAS and Bax, activation of caspase-3, -8, -9, and fragmentation of poly ADP ribose polymerase.

CONCLUSIONS

These results suggest that EEOM efficiently inhibits proliferation of HepG2 cells by inducing both G2/M arrest and apoptosis via intrinsic and extrinsic pathways, and EEOM may be used as a cancer chemopreventive agent in the food or nutraceutical industry.

Derivate isocorydine inhibits cell proliferation in hepatocellular carcinoma cell lines by inducing G2/M cell cycle arrest and apoptosis

We have previously demonstrated that isocorydine (ICD) can be served as a potential antitumor agent in hepatocellular carcinoma (HCC). A novel derivate of isocorydine (d-ICD) could significantly improve its anticancer activity in tumors. However, the molecular mechanisms of d-ICD on HCC cells remain to be unclear. In this study, we observed that d-ICD inhibited cell proliferation and induced apoptosis of HCC cells in a concentration-dependent manner. We found d-ICD induced G2/M cycle arrest of HCC cells via DNA damage 45 alpha (GADD45A) and p21 pathway in vitro and in vivo. In d-ICD-treated cells, cell cycle-related proteins cyclin B1 and p-CDC2 were upregulated and p-cyclin B1, CDC2, and E2F1 were inhibited. p21 expression can be reversed by knockdown of GADD45A in d-ICD-treated HCC cells. Enforced expression of CCAAT/enhancer-binding protein β (C/EBPβ) in combination with d-ICD enhanced the p21 expression in HCC cells. Furthermore, the luciferase reporter assay showed that upregulation of GADD45A by C/EBPβ was achieved through the increase of GADD45A promoter activity. These findings indicate that d-ICD inhibits cell proliferation and induces cell cycle arrest through activation of C/EBPβ-GADD45A-p21 pathway in HCC cells. d-ICD might be a promising chemotherapeutic agent for the treatment of HCC.

The Topoisomerase 1 Inhibitor Austrobailignan-1 Isolated from Koelreuteria henryi Induces a G2/M-Phase Arrest and Cell Death Independently of p53 in Non-Small Cell Lung Cancer Cells

Koelreuteria henryi Dummer, an endemic plant of Taiwan, has been used as a folk medicine for the treatment of hepatitis, enteritis, cough, pharyngitis, allergy, hypertension, hyperlipidemia, and cancer. Austrobailignan-1, a natural lignan derivative isolated from Koelreuteria henryi Dummer, has anti-oxidative and anti-cancer properties. However, the effects of austrobailignan-1 on human cancer cells have not been studied yet. Here, we showed that austrobailignan-1 inhibited cell growth of human non-small cell lung cancer A549 and H1299 cell lines in both dose- and time-dependent manners, the IC₅₀ value (48 h) of austrobailignan-1 were 41 and 22 nM, respectively. Data from flow cytometric analysis indicated that treatment with austrobailignan-1 for 24 h retarded the cell cycle at the G2/M phase. The molecular event of austrobailignan-1-mediated G2/M phase arrest was associated with the increase of p21^Waf1/Cip1 and p27^Kip1 expression, and decrease of Cdc25C expression. Moreover, treatment with 100 nM austrobailignan-1 for 48 h resulted in a pronounced release of cytochrome c followed by the activation of caspase-2, -3, and -9, and consequently induced apoptosis. These events were accompanied by the increase of PUMA and Bax, and the decrease of Mcl-1 and Bcl-2. Furthermore, our study also showed that austrobailignan-1 was a topoisomerase 1 inhibitor, as evidenced by a relaxation assay and induction of a DNA damage response signaling pathway, including ATM, and Chk1, Chk2, γH2AX phosphorylated activation. Overall, our results suggest that austrobailignan-1 is a novel DNA damaging agent and displays a topoisomerase I inhibitory activity, causes DNA strand breaks, and consequently induces DNA damage response signaling for cell cycle G2/M arrest and apoptosis in a p53 independent manner.

Study on pharmacokinetics and tissue distribution of the isocorydine derivative (AICD) in rats by HPLC-DAD method

A simple and effective high-performance liquid chromatography with diode-array detection method coupled with a liquid-liquid extraction pretreatment has been developed for determining the pharmacokinetics and tissue distribution of a novel structurally modified derivative (8-acetamino-isocorydine) of isocorydine. According to the in vivo experiments data calculations by DAS 2.0 software, a two-compartment metabolic model was suitable for describing the pharmacokinetic of 8-acetamino-isocorydine in rats. 8-Acetamino-isocorydine was absorbed well after oral administration, and the absolute bioavailability was 76.5%. The half-life of 8-acetamino-isocorydine after intravenous and oral administration was 2.2 h and 2.0 h, respectively. In vivo, 8-acetamino-isocorydine was highly distributed in the lungs, kidney and liver; however, relatively little entered the brain, suggesting that 8-acetamino-isocorydine could not easily pass through the blood brain barrier. Our work describes the first characterization of the pharmacokinetic parameters and tissue distribution of 8-acetamino-isocorydine. The acquired data will provide useful information for the in vivo pharmacology of 8-acetamino-isocorydine, and can be applied to new drug research.

Activity of alkaloids on peptic ulcer: what's new?

Peptic ulcer is a common disease characterized by lesions that affect the mucosa of the esophagus, stomach and/or duodenum, and may extend into the muscular layer of the mucosa. Natural products have played an important role in the process of development and discovery of new drugs, due to their wide structural diversity and present, mostly specific and selective biological activities. Among natural products the alkaloids, biologically active secondary metabolites, that can be found in plants, animals or microorganisms stand out. The alkaloids are compounds consisting of a basic nitrogen atom that may or may not be part of a heterocyclic ring. This review will describe 15 alkaloids with antiulcer activity in animal models and in vitro studies.

Isocorydine derivatives and their anticancer activities

In order to improve the anticancer activity of isocorydine (ICD), ten isocorydine derivatives were prepared through chemical structure modifications, and their in vitro and in vivo activities were experimentally investigated. 8-Amino-isocorydine (8) and 6a,7-dihydrogen-isocorydione (10) could inhibit the growth of human lung (A549), gastric (SGC7901) and liver (HepG2) cancer cell lines in vitro. Isocorydione (2) could inhibit the tumor growth of murine sarcoma S180-bearing mice, and 8-acetamino-isocorydine (11), a pro-drug of 8-amino-isocorydine (8), which is instable in water solution at room temperature, had a good inhibitory effect on murine hepatoma H22-induced tumors. The results suggested that the isocorydine structural modifications at C-8 could significantly improve the biological activity of this alkaloid, indicating its suitability as a lead compound in the development of an effective anticancer agent.

Ethnobotany, phytochemistry and pharmacology of Stephania rotunda Lour

ETHNOPHARMACOLOGICAL RELEVANCE

Stephania rotunda Lour. (Menispermaceae) is an important traditional medicinal plant that is grown in Southeast Asia. The stems, leaves, and tubers have been used in the Cambodian, Lao, Indian and Vietnamese folk medicine systems for years to treat a wide range of ailments, including asthma, headache, fever, and diarrhoea.

AIM OF THE REVIEW

To provide an up-to-date, comprehensive overview and analysis of the ethnobotany, phytochemistry, and pharmacology of Stephania rotunda for its potential benefits in human health, as well as to assess the scientific evidence of traditional use and provide a basis for future research directions.

MATERIAL AND METHODS

Peer-reviewed articles on Stephania rotunda were acquired via an electronic search of the major scientific databases (Pubmed, Google Scholar, and ScienceDirect). Data were collected from scientific journals, theses, and books.

RESULTS

The traditional uses of Stephania rotunda were recorded in countries throughout Southeast Asia (Cambodia, Vietnam, Laos, and India). Different parts of Stephania rotunda were used in traditional medicine to treat about twenty health disorders. Phytochemical analyses identified forty alkaloids. The roots primarily contain l-tetrahydropalmatine (l-THP), whereas the tubers contain cepharanthine and xylopinine. Furthermore, the chemical composition differs from one region to another and according to the harvest period. The alkaloids exhibited approximately ten different pharmacological activities. The main pharmacological activities of Stephania rotunda alkaloids are antiplasmodial, anticancer, and immunomodulatory effects. Sinomenine, cepharanthine, and l-stepholidine are the most promising components and have been tested in humans. The pharmacokinetic parameters have been studied for seven compounds, including the three most promising compounds. The toxicity has been evaluated for liriodenine, roemerine, cycleanine, l-tetrahydropalmatine, and oxostephanine.

CONCLUSION

Stephania rotunda is traditionally used for the treatment of a wide range of ailments. Pharmacological investigations have validated different uses of Stephania rotunda in folk medicine. The present review highlights the three most promising compounds of Stephania rotunda, which could constitute potential leads in various medicinal fields, including malaria and cancer.

Cytotoxicity of Aporphine, Protoberberine, and Protopine Alkaloids from Dicranostigma leptopodum (Maxim.) Fedde

Nine alkaloids with three different structural skeletons were isolated from Dicranostigma leptopodum (Maxim.) Fedde (Papaveraceae) by repeated silica gel column chromatography. Their chemical structures were identified on the basic of physicochemical and spectroscopic data. Among them, 10-O-methylhernovine (1), nantenine (2), corytuberine (3), lagesianine A (4), and dihydrocryptopine (9) were first isolated from this plant. With a series of cytotoxic tests, compounds 2, 3, and 7 displayed cytotoxicity against SMMC-7721 with IC₅₀ values of 70.08 ± 4.63, 73.22 ± 2.35, and 27.77 ± 2.29 μM, respectively.

Chk1, but not Chk2, is responsible for G2/M phase arrest induced by diallyl disulfide in human gastric cancer BGC823 cells

Diallyl disulfide (DADS) has been shown to cause G2/M phase cell cycle arrest in several human cancers. Here we demonstrate a mechanism by which DADS induces G2/M phase arrest in BGC823 human gastric cancer cells via Chk1. From cell cycle gene array results, we next confirmed that cyclin B1 expression was decreased by DADS, while the expression of p21, GADD45α and p53 were increased. Despite the lack of change in Chk1 gene expression in response to DADS according to the array analysis, intriguingly overexpression of Chk1, but not Chk2, exhibited increased accumulation in G2/M phase. Moreover, overexpression of Chk1 promoted the effect of DADS-induced G2/M arrest. Augmented phosphorylation of Chk1 by DADS was observed in Chk1-transfected cells, followed by downregulation of Cdc25C and cyclin B1 proteins. In contrast, phosphorylated Chk2 showed no obvious change in Chk2-transfected cells after DADS treatment. Furthermore, knockdown of Chk1 by siRNA partially abrogated DADS-induced downregulation of Cdc25C and cyclin B1 proteins and G2/M arrest. In contrast, knockdown of Chk2 did not show these effects. Therefore, these data indicate that DADS may specifically modulate Chk1 phosphorylation, and DADS-induced G2/M phase arrest in BGC823 cells could result in part from Chk1-mediated inhibition of the Cdc25C/cyclin B1 pathway.

A new quaternary protoberberine alkaloid isolated from Dicranostigma leptopodum (Maxim) Fedde

Phytochemical investigation of the whole plants of Dicranostigma leptopodum (Maxim) Fedde has led to the isolation of two quaternary protoberberine alkaloids 5-hydroxy-coptisine (1) and berberrubine (2). This type of alkaloids was isolated from the genus Dicranostigma for the first time and the new compound structure (1) was elucidated by various spectroscopic methods including 2D NMR techniques (gCOSY, HMQC and HMBC) and HR-ESI-MS.

Isocorydine targets the drug-resistant cellular side population through PDCD4-related apoptosis in hepatocellular carcinoma

Isocorydine (ICD), an anticancer agent under current evaluation, decreased the percentage of side population (SP) cells significantly in hepatocellular carcinoma (HCC) cell lines. ICD treatment sensitized cancer cells to doxorubicin (DXR), a conventional clinical chemotherapeutic drug for HCC. We found that ICD decreased the percentage of SP cells in HCC cell lines by preferentially killing SP cells. In the early stage of treatment, ICD inhibited SP cell growth by arresting cells in G2/M; later, it induced apoptosis. Our xenograft model confirmed that ICD selectively reduced the size and weight of SP-induced tumor masses in vivo. Furthermore, it was found that programmed cell death 4 (PDCD4), a tumor suppressor gene, was relatively low when expressed in SP cells compared with non-SP cells, and its expression level was remarkably elevated when cells were treated with ICD. Taken together, these data suggest that ICD is a drug that may target the SP cells of HCC.