Antiproliferative and apoptotic effects of tetrandrine on different human hepatoma cell lines

Exploring the recent trends in perturbing the cellular signaling pathways in cancer by natural products

Cancer is commonly thought to be the product of irregular cell division. According to the World Health Organization (WHO), cancer is the major cause of death globally. Nature offers an abundant supply of bioactive compounds with high therapeutic efficacy. Anticancer effects have been studied in a variety of phytochemicals found in nature. When Food and Drug Administration (FDA)-approved anticancer drugs are combined with natural compounds, the effectiveness improves. Several agents have already progressed to clinical trials based on these promising results of natural compounds against various cancer forms. Natural compounds prevent cancer cell proliferation, development, and metastasis by inducing cell cycle arrest, activating intrinsic and extrinsic apoptosis pathways, generating reactive oxygen species (ROS), and down-regulating activated signaling pathways. These natural chemicals are known to affect numerous important cellular signaling pathways, such as NF-B, MAPK, Wnt, Notch, Akt, p53, AR, ER, and many others, to cause cell death signals and induce apoptosis in pre-cancerous or cancer cells without harming normal cells. As a result, non-toxic “natural drugs” taken from nature’s bounty could be effective for the prevention of tumor progression and/or therapy of human malignancies, either alone or in combination with conventional treatments. Natural compounds have also been shown in preclinical studies to improve the sensitivity of resistant cancers to currently available chemotherapy agents. To summarize, preclinical and clinical findings against cancer indicate that natural-sourced compounds have promising anticancer efficacy. The vital purpose of these studies is to target cellular signaling pathways in cancer by natural compounds.

Regulatory Role of Apoptotic and Inflammasome Related Proteins and Their Possible Functional Aspect in Thiram Associated Tibial Dyschondroplasia of Poultry

Tibial dyschondroplasia debilities apoptotic and inflammasomal conditions that can further destroy chondrocytes. Inflammasomes are specialized protein complexes that process pro-inflammatory cytokines, e.g., interleukin-1β (IL-1β) and IL-18. Moreover, there is mounting evidence that many of the signaling molecules that govern programmed cell death also affect inflammasome activation in a cell-intrinsic way. During the last decade, apoptotic functions have been described for signaling molecules involving inflammatory responses and cell death pathways. Considering these exceptional developments in the knowledge of processes, this review gives a glimpse of the significance of these two pathways and their connected proteins in tibial dyschondroplasia. The current review deeply elaborates on the elevated level of signaling mediators of mitochondrial-mediated apoptosis and the inflammasome. Although investigating these pathways’ mechanisms has made significant progress, this review identifies areas where more study is especially required. It might lead to developing innovative therapeutics for tibial dyschondroplasia and other associated bone disorders, e.g., osteoporosis and osteoarthritis, where apoptosis and inflammasome are the significant pathways.

Targeting the two-pore channel 2 in cancer progression and metastasis

The importance of Ca²⁺ signaling, and particularly Ca²⁺ channels, in key events of cancer cell function such as proliferation, metastasis, autophagy and angiogenesis, has recently begun to be appreciated. Of particular note are two-pore channels (TPCs), a group of recently identified Ca²⁺-channels, located within the endolysosomal system. TPC2 has recently emerged as an intracellular ion channel of significant pathophysiological relevance, specifically in cancer, and interest in its role as an anti-cancer drug target has begun to be explored. Herein, an overview of the cancer-related functions of TPC2 and a discussion of its potential as a target for therapeutic intervention, including a summary of clinical trials examining the TPC2 inhibitors, naringenin, tetrandrine, and verapamil for the treatment of various cancers is provided.

Tetrandrine Suppresses Human Brain Glioblastoma GBM 8401/luc2 Cell-Xenografted Subcutaneous Tumors in Nude Mice In Vivo

Tetrandrine (TET), a bisbenzylisoquinoline (BBI) alkaloid, is isolated from the plant Stephania tetrandra S. Moore and has a wide range of biological activity, including anticancer properties in vitro and in vivo. At first, we established a luciferase-expressing stable clone that was named GBM 8401/luc2 cells. Herein, the primary results indicated that TET reduced the total cell viability and induced cell apoptosis in GBM 8401/luc2 human glioblastoma cells. However, there is no available information showing that TET suppresses glioblastoma cells in vivo. Thus, we investigated the effects and mechanisms of TET on a GBM 8401/luc2 cell-generated tumor in vivo. After the tumor volume reached 100-120 mm³ in subcutaneously xenografted nude mice, all of the mice were randomly divided into three groups: Group I was treated with phosphate-buffered solution (PBS) containing 0.1% dimethyl sulfoxide, Group II with 25 mg/kg of TET, and Group III with 50 mg/kg of TET. All mice were given the oral treatment of PBS or TET by gavage for 21 days, and the body weight and tumor volumes were recorded every 5 days. After treatment, individual tumors, kidneys, livers, and spleens were isolated from each group. The results showed that TET did not affect the body weights, but it significantly decreased the tumor volumes. The TET treatment at 50 mg/kg had a two-fold decrease in tumor volumes than that at 25 mg/kg when compared to the control. TET decreased the total photon flux, and treatment with TET at 50 mg/kg had a lower total photon flux than that at 25 mg/kg, as measured by a Xenogen IVIS imaging system. Moreover, the higher TET treatment had lower tumor volumes and weights than those of the lower dose. The apoptosis-associated protein expression in the tumor section was examined by immunohistochemical analysis, and the results showed that TET treatment reduced the levels of c-FLIP, MCL-1, and XIAP but increased the signals of cleaved-caspase-3, -8, and -9. Furthermore, the hematoxylin and eosin (H & E) staining of kidney, liver, and spleen tissues showed no significant difference between the TET-treated and control groups. Overall, these observations demonstrated that TET suppressed subcutaneous tumor growth in a nude-mice model via the induction of cell apoptosis.

Naturally occurring heterocyclic anticancer compounds

Naturally occurring heterocyclic scaffolds are key ingredients for the development of various therapeutics employed for biomedical applications. Heterocyclic pharmacophores are widely disseminated and have been befallen in almost all categories of drugs for the alleviation of myriad ailments including diabetes, neurodegenerative, psychiatric, microbial infections, disastrous cancers etc. Countless fused heterocyclic anticancerous templates are reported to display antimetabolite, antioxidant, antiproliferative, cytostatic etc. pharmacological actions via targeting different signaling pathways (cell cycle, PI-3kinase/Akt, p53, caspase extrinsic pathway etc.), overexpressive receptors (EGRF, HER2, EGF, VEGF etc.) and physiological enzymes (topoisomerase I and II, cyclin dependent kinase etc.). A compiled description on various natural sources (plants, microbes, marine) containing anticancer agents comprising heterocyclic ring specified with presence of nitrogen (vincristine, vinblastine, indole-3-carbinol, meridianins, piperine, lamellarins etc.), oxygen (paclitaxel, halichondrin B, quercetin, myricetin, kaempferol etc.) and sulphur atoms (brugine, fucoidan, carrageenan etc.) are displayed here along with their molecular level cytotoxic action and therapeutic applications.

Tetrandrine Enhances H2O2-Induced Apoptotic Cell Death Through Caspase-dependent Pathway in Human Keratinocytes

BACKGROUND

Tetrandrine, a bis-benzylisoquinoline alkaloid, induces apoptosis of many types of human cancer cell. Hydrogen peroxide (H₂O₂) is a reactive oxygen species inducer; however, there are no reports to show whether pre-treatment of tetrandrine with H₂O₂ induces more cell apoptosis than H₂O₂ alone. Thus, the present study investigated the effects of tetrandrine on H₂O₂-induced cell apoptosis of human keratinocytes, HaCaT, in vitro.

MATERIALS AND METHODS

HaCaT cells were pre-treated with and without tetrandrine for 1 h, and then treated with H₂O₂ for examining cell morphological changes and cell viability using contrast-phase microscopy and propidium iodide (PI) exclusion assay, respectively. Cells were measured apoptotic cell death by using annexin V/PI double staining and further analyzed by flow cytometer. Cells were further assessed for DNA condensation using 2-(4-amidinophenyl)-6-indolecarbamidine staining. Western blotting was used to measure expression of apoptosis-associated proteins and confocal laser microscopy was used to measure the protein expression and nuclear translocation from the cytoplasm to nuclei.

RESULTS

Pre-treatment of tetrandrine for 1 h and treatment with H₂O₂ enhanced H₂O₂-induced cell morphological changes and reduced cell viability, whilst increasing apoptotic cell death and DNA condensation. Furthermore, tetrandrine significantly increased expression of reactive oxygen species-associated proteins such as superoxide dismutase (Cu/Zn) and superoxide dismutase (Mn) but significantly reduced the level of catalase, which was also confirmed by confocal laser microscopy. It also increased expression of DNA repair-associated proteins ataxia telangiectasia mutated, ataxia-telangectasia and Rad3-related, phospho-P53, P53 and phosphorylated histone H2AX, and of pro-apoptotic proteins BCL2 apoptosis regulator-associated X-protein, caspase-3, caspase-8, caspase-9 and poly ADP ribose polymerase in HaCaT cells.

CONCLUSION

These are the first and novel findings showing tetrandrine enhances H₂O₂-induced apoptotic cell death of HaCaT cells and may provide a potent approach for the treatment of proliferated malignant keratinocytes.

An overview on the chemistry, pharmacology and anticancer properties of tetrandrine and fangchinoline (alkaloids) from Stephania tetrandra roots

Tetrandrine (TET) and fangchinoline (FAN) are dominant bisbenzylisoquinoline (BBIQ) alkaloids from the roots of Stephania tetrandra of the family Menispermaceae. BBIQ alkaloids comprise two benzylisoquinoline units linked by oxygen bridges. The molecular structures of TET and FAN are exactly the same, except that TET has a methoxy (-OCH₃) group, while FAN has a hydroxyl (-OH) group at C7. In this overview, the current knowledge on the chemistry, pharmacology and anticancer properties of TET and FAN have been updated. The focus is on colon and breast cancer cells, because they are most susceptible to TET and FAN, respectively. Against colon cancer cells, TET inhibits cell proliferation and tumor growth by inducing apoptosis and G1 cell cycle arrest, and suppresses adhesion, migration and invasion of cells. Against breast cancer cells, FAN inhibits cell proliferation by inducing apoptosis, G1-phase cell cycle arrest and inhibits cell migration. The processes involve various molecular mechanisms and signaling pathways. Some insights on the ability of TET and FAN to reverse multi-drug resistance in cancer cells and suggestions for future research are provided.

Neothalfine, a potent natural anti-tumor agent against metastatic colorectal cancer and its primary mechanism

Neothalfine is a natural bisbenzylisoquinoline alkaloid with the abundant resource in medicinal plants and has not been reported its anti-tumor efficacy. In the present study, the anti-tumor efficacy was investigated and it showed broad-spectrum activity against several cancer cell lines, especially metastatic colorectal cancer (HCT116, SW620, T84) with the IC₅₀ values of 7.2, 5.9, 8.2 nM, respectively, roughly equal to well-known anti-tumor agent docetaxel (4.0, 4.7, 2.7 nM) and nearly 1000 folds than CPT-11 (4.4, 5.1, 6.9 μM). Furthermore, neothalfine inhibited colorectal cell proliferation by resulting in cell cycle arrest at the G2/M phase and induced apoptosis through the dysfunction of mitochondria to trigger intrinsic apoptotic pathway by untargeted metabolomic method, mitochondrial membrane potential, and caspase-3/7 activity assay. Moreover, neothalfine damaged colorectal cancer clonal spheres expansion significantly at the concentration of 3.5 nM with nearly 1000 folds efficacy than CPT-11 (3.0 µM). The results supported that neothalfine might be an anti-tumor lead for further investigation.

Treatment of tibial dyschondroplasia with traditional Chinese medicines: "Lesson and future directions"

Tibial dyschondroplasia (TD) is a metabolic tibiotarsal bone disease in rapidly growing birds throughout the world, which is characterized by gait disorders, reduced growth, and in an unrecoverable lameness in many cases. The short production cycle in chickens, long metabolism cycle in most of the drugs with the severe drug residue, and high treatment cost severely restrict the enthusiasm for the treatment of TD. Traditional Chinese medicine (TCM) has been used for the prevention, treatment, and cure of avian bone diseases. Previously, a couple of traditional Chinese medicines has been reported being useful in treating TD. This review will discuss the TCM used in TD and the alternative TCM to treat TD. Selecting a TCM approach and its pharmacologic effects on TD chickens mainly focused on the differentiation, proliferation, and apoptosis of chondrocytes, angiogenesis, matrix metabolism, oxidative damage, cytokines, and calcification of cartilage in tibia.

Tetrandrine: a review of its anticancer potentials, clinical settings, pharmacokinetics and drug delivery systems

OBJECTIVES

Tetrandrine, a natural bisbenzylisoquinoline alkaloid, possesses promising anticancer activities on diverse tumours. This review provides systematically organized information on cancers of tetrandrine in vivo and in vitro, discuss the related molecular mechanisms and put forward some new insights for the future investigations.

KEY FINDINGS

Anticancer activities of tetrandrine have been reported comprehensively, including lung cancer, colon cancer, bladder cancer, prostate cancer, ovarian cancer, gastric cancer, breast cancer, pancreatic cancer, cervical cancer and liver cancer. The potential molecular mechanisms corresponding to the anticancer activities of tetrandrine might be related to induce cancer cell apoptosis, autophagy and cell cycle arrest, inhibit cell proliferation, migration and invasion, ameliorate metastasis and suppress tumour cell growth. Pharmaceutical applications of tetrandrine combined with nanoparticle delivery system including liposomes, microspheres and nanoparticles with better therapeutic efficiency have been designed and applied encapsulate tetrandrine to enhance its stability and efficacy in cancer treatment.

SUMMARY

Tetrandrine was proven to have definite antitumour activities. However, the safety, bioavailability and pharmacokinetic parameter studies on tetrandrine are very limited in animal models, especially in clinical settings. Our present review on anticancer potentials of tetrandrine would be necessary and highly beneficial for providing guidelines and directions for further research of tetrandrine.

The Biological Activity of Natural Alkaloids against Herbivores, Cancerous Cells and Pathogens

The growing incidence of microorganisms that resist antimicrobials is a constant concern for the scientific community, while the development of new antimicrobials from new chemical entities has become more and more expensive, time-consuming, and exacerbated by emerging drug-resistant strains. In this regard, many scientists are conducting research on plants aiming to discover possible antimicrobial compounds. The secondary metabolites contained in plants are a source of chemical entities having pharmacological activities and intended to be used for the treatment of different diseases. These chemical entities have the potential to be used as an effective antioxidant, antimutagenic, anticarcinogenic and antimicrobial agents. Among these pharmacologically active entities are the alkaloids which are classified into a number of classes, including pyrrolizidines, pyrrolidines, quinolizidines, indoles, tropanes, piperidines, purines, imidazoles, and isoquinolines. Alkaloids that have antioxidant properties are capable of preventing a variety of degenerative diseases through capturing free radicals, or through binding to catalysts involved indifferent oxidation processes occurring within the human body. Furthermore, these entities are capable of inhibiting the activity of bacteria, fungi, protozoan and etc. The unique properties of these secondary metabolites are the main reason for their utilization by the pharmaceutical companies for the treatment of different diseases. Generally, these alkaloids are extracted from plants, animals and fungi. Penicillin is the most famous natural drug discovery deriving from fungus. Similarly, marines have been used as a source for thousands of bioactive marine natural products. In this review, we cover the medical use of natural alkaloids isolated from a variety of plants and utilized by humans as antibacterial, antiviral, antifungal and anticancer agents. An example for such alkaloids is berberine, an isoquinoline alkaloid, found in roots and stem-bark of Berberis asculin P. Renault plant and used to kill a variety of microorganisms.

Tetrandrine inhibits colon carcinoma HT-29 cells growth via the Bcl-2/Caspase 3/PARP pathway and G1/S phase

Tetrandrine (Tet) bisbenzylisoquinoline alkaloids isolated from Stephania tetrandra and other related species of Menispermaceae. It has been demonstrated to have positive therapeutic effects on cardiovascular disease, hypertension, silicosis, autoimmune diseases. In recent years, some reports have shown that Tet has anticancer activity in human cancers. To explore the pharmacological activity and mechanism of Tet on colon cancer and its unique advantages as a natural product. In the present study, analyses of the cell cycle, apoptosis, targets prediction, molecular docking, and alterations in protein levels were performed to elucidate how Tet functions in colon cancer. We found that Tet robustly induced arrest at the G1 phase in colon cancer cell line HT-29. It induced HT-29 cell apoptosis in a dose-dependent manner. Similarly, analysis of protein expression levels in HT-29 cells showed down-regulation of Bcl-2, pro-caspase 3, pro-caspase 8, PARP, cyclin D1 (CCND1), cyclin-dependent kinase 4 (CDK 4), and up-regulation of Bax, active caspase 3, and active caspase 8. These results indicate that Tet induces apoptosis of colon cancer cells through the mitochondrial pathway and caspase family pathway. Molecular docking showed interaction effects and binding energy. Comparing with the CDK4 inhibitors ribociclib and palbociclib, the docking energy is similar to the docked amino acid residues. Therefore, we conclude that Tet and the CCND1/CDK4 compound could form hydrogen bonds and a stable compound structure, which can inhibit colon cancer cells proliferation by regulating CCND1/CDK4 compound and its downstream proteins phosphorylated Rb (p-Rb). In summary, Tet may be a potential drug for colon cancer therapy.

Synthesis of novel tetrandrine derivatives and their inhibition against NSCLC A549 cells

A series of novel tetrandrine (Tet) derivatives were synthesized through Suzuki -Miyaura reaction and evaluated for their cytotoxicity against human non-small cell lung carcinoma (NSCLC) A549 cells. Interestingly, most of derivatives showed similar cytotoxicity to Tet against NSCLC A549 cells, and particularly, compounds Y5, Y6, Y9 and Y11 showed the most significant cytotoxic effects with IC₅₀ values ranging from 3.87 to 4.66 mM. The present study is expected to contribute to the future design of more effective anticancer agents in lung cancer chemotherapy.

Synergistic effects of tetrandrine combined with ionizing radiation on a murine colorectal carcinoma‑bearing mouse model

Tetrandrine (TET), a traditional Chinese clinical agent, has been used for the treatment of many diseases, including cancers. The purpose of the present study was to investigate the combined effects of TET and ionizing radiation (IR) on murine CT26 colorectal adenocarcinoma cells in vitro and in vivo. A CT26 cell line transfected with dual HSV-1 thymidine kinase and firefly luciferase (luc) reporter genes was used. The half-maximal inhibitory concentration (IC₅₀) of TET in CT26/tk-luc cells was ~10 µM. An additive effect was observed after combination of both agents based on a colony formation assay. Apoptosis and cleaved caspase-3 levels were increased significantly in cells after combination treatment, as shown by flow cytometric analysis, DNA fragmentation and western blotting. However, tumor growth inhibition and therapeutic efficacy of TET combined with IR in vivo were identified to be synergistic, as monitored by tumor growth delay time, measured with a digital caliper. A significant inhibition of tumor growth was identified in the combination group compared with the radiation only group. Furthermore, non-invasive bioluminescent imaging (BLI) and gamma scintigraphy were also used to evaluate therapeutic efficacy. Both modalities revealed that the best tumor growth control was under combination treatment among all groups. The present study demonstrated that TET is not only beneficial for chemotherapy, but also has potential as a radiosensitizer for the treatment of cancer.

Tetrandrine, a Chinese plant-derived alkaloid, is a potential candidate for cancer chemotherapy

Cancer is a disease caused by the abnormal proliferation and differentiation of cells governed by tumorigenic factors. Chemotherapy is one of the major cancer treatment strategies, and it functions by targeting the physiological capabilities of cancer cells, including sustained proliferation and angiogenesis, the evasion of programmed cell death, tissue invasion and metastasis. Remarkably, natural products have garnered increased attention in the chemotherapy drug discovery field because they are biologically friendly and have high therapeutic effects. Tetrandrine, isolated from the root of Stephania tetrandra S Moore, is a traditional Chinese clinical agent for silicosis, autoimmune disorders, inflammatory pulmonary diseases, cardiovascular diseases and hypertension. Recently, the novel anti-tumor effects of tetrandrine have been widely investigated. More impressive is that tetrandrine affects multiple biological activities of cancer cells, including the inhibition of proliferation, angiogenesis, migration, and invasion; the induction of apoptosis and autophagy; the reversal of multidrug resistance (MDR); and the enhancement of radiation sensitization. This review focuses on introducing the latest information about the anti-tumor effects of tetrandrine on various cancers and its underlying mechanism. Moreover, we discuss the nanoparticle delivery system being developed for tetrandrine and the anti-tumor effects of other bisbenzylisoquinoline alkaloid derivatives on cancer cells. All current evidence demonstrates that tetrandrine is a promising candidate as a cancer chemotherapeutic.

Tetrandrine and cancer - An overview on the molecular approach

Tetrandrine has been known in the treatment of tuberculosis, hyperglycemia, negative ionotropic and chronotropic effects on myocardium, malaria, cancer and fever since years together. It has been known that, tetrandrine could modulate multiple signaling molecules such as kinases of cell cycle and rat sarcoma (RAS) pathway along with proteins of tumor suppressor genes, autophagy related, β-catenins, caspases, and death receptors. Moreover, tetrandrine exhibited reversal of drug resistance by modulating P-glyco protein (P-gp) expression levels in different cancers which is an added advantage of this compound compared to other chemotherapy drugs. Though, bioavailability of tetrandrine is a limiting factor, the anticancer activity was observed in animal models without changing any pharmacokinetic parameters. In the present review, role of tetrandrine as kinase inhibitor, inducer of autophagy and caspase pathways and suppressor of RAS mediated cell proliferation were discussed along with inhibition of angiogenesis. It has also been discussed that how tetrandrine potentiate anticancer effect in different types of cancers by modulating multidrug resistance under in vitro and in vivo trials including the available literature on the clinical trials.

Tetrandrine Exerts a Radiosensitization Effect on Human Glioma through Inhibiting Proliferation by Attenuating ERK Phosphorylation

Tetrandrine (Tet), a bisbenzylisoquinoline alkaloid, has been reported to have a radiosensitization effect on tumors. However, its effects on human glioma and the specific molecular mechanisms of these effects remain unknown. In this study, we demonstrated that Tet has a radiosensitization effect on human glioma cells. It has been hypothesized that Tet has a radiosensitization effect on glioma cells by affecting the glioma cell cycle and DNA repair mechanism and that ERK mediates these activities. Therefore, we conducted detailed analyses of the effects of Tet on the cell cycle by performing flow cytometric analysis and on DNA repair by detecting the expression of phosphorylated H2AX by immunofluorescence. We used western blot analysis to investigate the role of ERK in the effect of Tet on the cell cycle and DNA repair. The results revealed that Tet exerts its radiosensitization effect on glioma cells by inhibiting proliferation and decreasing the expression of phosphorylated ERK and its downstream proteins. In summary, our data indicate that ERK is involved in Tet-induced radiosensitization of glioma cells via inhibition of glioma cell proliferation or of the cell cycle at G0/G1 phase.

Bioactive compounds of Aspergillus terreus-F7, an endophytic fungus from Hyptis suaveolens (L.) Poit

The compounds terrein (1), butyrolactone I (2), and butyrolactone V (3) were isolated from the ethyl acetate extract (EtOAc) of the endophytic fungus Aspergillus terreus-F7 obtained from Hyptis suaveolens (L.) Poit. The extract and the compounds presented schistosomicidal activity against Schistosoma mansoni; at 100 µg/mL for EtOAc extract, 1297.3 µM for compound 1, 235.6 µM for compound 2, and 454.1 µM for compound 3, they killed 100% of the parasites after 72 h of treatment. Compounds 1, 2, and 3 exerted moderate leishmanicidal activity against Leishmania amazonensis (IC₅₀ ranged from 23.7 to 78.6 µM). At 235.6 and 227.0 µM, compounds 2 and 3, respectively, scavenged 95.92 and 95.12% of the DPPH radical (2,2-diphenyl-1-picryl-hydrazyl), respectively. Regarding the cytotoxicity against the breast tumor cell lines MDA-MB-231 and MCF-7, compound 2 gave IC₅₀ of 34.4 and 17.4 µM, respectively, while compound 3 afforded IC₅₀ of 22.2 and 31.9 µM, respectively. At 117.6 µM, compound 2 inhibited the growth of and killed the pathogen Escherichia coli (ATCC 25922). Compounds 1, 2, and 3 displayed low toxicity against the normal line of human lung fibroblasts (GM07492A cells), with IC₅₀ of 15.3 × 10³, 3.4 × 10³, and 5.8 × 10³ µM, respectively. This is the first report on (i) the in vitro schistosomicidal and leishmanicidal activities of the EtOAc extract of A. terreus-F7 and compounds 1, 2, and 3; and (ii) the antitumor activity of compounds 2 and 3 against MDA-MB-231 and MCF-7 cells.

Anti-proliferative and apoptotic effects of S1, a tetrandrine derivative, in human gastric cancer BGC-823 cells

The aim of the study was to investigate the anti-proliferation and apoptosis-inducing effects of S1, a novel tetrandrine derivative, in human gastric cancer BGC-823 cells and explore the possible mechanism of action. The anti-proliferative activity was determined by MTT assay; the induction of cell cycle arrest and apoptosis were detected by flow cytometry. Quantitative real time RT-PCR and Western blotting were used to evaluate the mRNA and protein expression levels in mitochondrial pathway. S1 significantly reduced cell viability and induced a G2/M phase arrest and apoptosis in dose- and time-dependent manner. Further studies showed that S1 increased mRNA and protein expression of Bax and the Bax/Bcl-2 ratio. Moreover, S1 decreased the protein expression of procaspase-9 and procaspase-3, suggesting that the induction of apoptosis may be related to the alteration of the ratio of Bax/Bcl-2 and the activation of caspases. These findings suggested that S1 merits further investigation as a novel therapeutic agent for the treatment of human gastric cancer.

Tetrandrine induces programmed cell death in human oral cancer CAL 27 cells through the reactive oxygen species production and caspase-dependent pathways and associated with beclin-1-induced cell autophagy

Tetrandrine, a bisbenzylisoquinoline alkaloid, is extracted from the root of the Chinese herb Radix Stephania tetrandra S Moore. This compound has antitumor activity in different cancer cell types. In this study, the effects of tetrandrine on human oral cancer CAL 27 cells were examined. Results indicated that tetrandrine induced cytotoxic activity in CAL 27 cells. Effects were due to cell death by the induction of apoptosis and accompany with autophagy and these effects were concentration- and time-dependent manners. Tetrandrine induced apoptosis was accompanied by alterations in cell morphology, chromatin fragmentation, and caspase activation in CAL 27 cells. Tetrandrine treatment also induced intracellular accumulation of reactive oxygen species (ROS). The generation of ROS may play an important role in tetrandrine-induced apoptosis. Tetrandrine triggered LC3B expression and induced autophagy in CAL 27 cells. Tetrandrine induced apoptosis and autophagy were significantly attenuated by N-acetylcysteine pretreatment that supports the involvement of ROS production. Tetrandrine induced cell death may act through caspase-dependent apoptosis with Beclin-1-induced autophagy in human oral cancer cells. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 329-343, 2017.

Tetrandrine Induces Apoptosis of Human Nasopharyngeal Carcinoma NPC-TW 076 Cells through Reactive Oxygen Species Accompanied by an Endoplasmic Reticulum Stress Signaling Pathway

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy of the head and neck and the incidence is higher in Southeast Asia. Tetrandrine (TET) is a bisbenzylisoquinoline alkaloid, a natural product, and exhibits biological activities including action against many human cancer cell lines. However, the molecular mechanism of TET-induced cell apoptosis in human NPC cells is still unclear. In the present study, we investigated TET-induced apoptotic cell death and associated possible signal pathways on human nasopharyngeal carcinoma NPC-TW 076 cells in vitro. Phase contrast microscopy was used to examine cell morphology and DAPI staining was used to examine chromatin condensation. Flow cytometry assay was used to measure total viable cells, cell cycle and sub-G₁ phase distribution, reactive oxygen species (ROS), Ca²⁺, and mitochondria membrane potential (ΔΨm) in NPC-TW 076 cells. Results indicate that TET induced cell death through the cell morphological changes, caused G₀/G₁ phase arrest, increased ROS and Ca²⁺ production, and finally caused apoptotic cell death in NPC-TW 076 cells. There was no influence on the level of ΔΨm after TET treatment. Western blotting indicated that TET increased endoplasmic reticulum (ER) stress associated protein expression such as GADD153, GRP78, ATF-6α and ATF-6 βwhich indicated that TET induced cell death through ER stress. ER stress is a potential target in cancer treatment, so the ability of TET to induce ER stress response and to activate programming cell death in NPC-TW 076 cells make this molecule become a promising anticancer agent.

Tetrandrine--A molecule of wide bioactivity

Stephania tetrandra and other related species of Menispermaceae form the major source of the bisbenzylisoquinoline alkaloid - tetrandrine. The plant is extensively referenced in the Chinese Pharmacopoeia for its use in the Chinese medicinal system as an analgesic and diuretic agent and also in the treatment of hypertension and various other ailments, including asthma, tuberculosis, dysentery, hyperglycemia, malaria, cancer and fever. Tetrandrine, well-known to act as a calcium channel blocker, has been tested in clinical trials and found effective against silicosis, hypertension, inflammation and lung cancer without any toxicity. Recently, the efficacy of tetrandrine was tested against Mycobaterium tuberculosis, Candida albicans, Plasmodium falciparum and Ebola virus. Tetrandrine's pharmacological property has been proved to be through its action on different signalling pathways like reactive oxygen species, enhanced autophagic flux, reversal of multi drug resistance, caspase pathway, cell cycle arrest and by modification of calcium channels. The present review summarises current knowledge on the synthesis, distribution, extraction, structural elucidation, pharmacological properties and the mechanism of action of tetrandrine. Future perspectives in the clinical use of tetrandrine as a drug are also considered.

Tetrandrine induces apoptosis Via caspase-8, -9, and -3 and poly (ADP ribose) polymerase dependent pathways and autophagy through beclin-1/ LC3-I, II signaling pathways in human oral cancer HSC-3 cells

Tetrandrine is a bisbenzylisoquinoline alkaloid that was found in the Radix Stephania tetrandra S Moore. It had been reported to induce cytotoxic effects on many human cancer cells. In this study, we investigated the cytotoxic effects of tetrandrine on human oral cancer HSC-3 cells in vitro. Treatments of HSC-3 cells with tetrandrine significantly decreased the percentage of viable cells through the induction of autophagy and apoptosis and these effects are in concentration-dependent manner. To define the mechanism underlying the cytotoxic effects of tetrandrine, we investigated the critical molecular events known to regulate the apoptotic and autophagic machinery. Tetrandrine induced chromatin condensation, internucleosomal DNA fragmentation, activation of caspases-3, -8, and -9, and cleavage of poly (ADP ribose) polymerase (PARP) that were associated with apoptosis, and it also enhanced the expression of LC3-I and -II that were associated with the induction of autophagy in human squamous carcinoma cell line (HSC-3) cells. Tetrandrine induced autophagy in HSC-3 cells was significantly attenuated by bafilomycin A1 (inhibitor of autophagy) pre-treatment that confirmed tetrandrine induced cell death may be associated with the autophagy. In conclusion, we suggest that tetrandrine induced cell death may be through the induction of apoptosis as well as autophagy in human oral cancer HSC-3 cells via PARP, caspases/Becline I/LC3-I/II signaling pathways.

Preventive and Therapeutic Effects of Chinese Herbal Compounds against Hepatocellular Carcinoma

Traditional Chinese Medicines, unique biomedical and pharmaceutical resources, have been widely used for hepatocellular carcinoma (HCC) prevention and treatment. Accumulated Chinese herb-derived compounds with significant anti-cancer effects against HCC have been identified. Chinese herbal compounds are effective in preventing carcinogenesis, inhibiting cell proliferation, arresting cell cycle, inducing apoptosis, autophagy, cell senescence and anoikis, inhibiting epithelial-mesenchymal transition, metastasis and angiogenesis, regulating immune function, reversing drug resistance and enhancing the effects of chemotherapy in HCC. This paper comprehensively reviews these compounds and their effects on HCC. Finally, the perspectives and rational application of herbal compounds for HCC management are discussed.

Encapsulation of honokiol into self-assembled pectin nanoparticles for drug delivery to HepG2 cells

Self-assembled pectin nanoparticles was prepared and evaluated for delivering the hydrophobic drug, honokiol (HK), to HepG2 cells. These hydrophobic drug-loaded nanoparticles were developed without using any surfactant and organic solvent. Hydroxypropyl-β-cyclodextrin (HCD) was used to fabricate an inclusion complex with HK (HKHCD) to increase the solubility of the drug and thus facilitate its encapsulation and dispersion in the pectin nanoparticles. Investigation of the in vitro release indicated that the drug-loaded nanoparticles exhibited a higher drug release rate than free honokiol and an effective sustained-release. Cytotoxicity, cell apoptosis and cellular uptake studies further confirmed that the pectin nanoparticles with galactose residues generated higher cytotoxicity than free honokiol on HepG2 cells which highly expressed asialoglycoprotein receptors (ASGR). Nevertheless, these findings were not observed in ASGR-negative A549 cells under similar condition. Therefore, pectin nanoparticles demonstrated a specific active targeting ability to ASGR-positive HepG2 cells and could be used as a potential drug carrier for treatment of liver-related tumors.

Involvement of DNA damage response pathways in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has been known as one of the most lethal human malignancies, due to the difficulty of early detection, chemoresistance, and radioresistance, and is characterized by active angiogenesis and metastasis, which account for rapid recurrence and poor survival. Its development has been closely associated with multiple risk factors, including hepatitis B and C virus infection, alcohol consumption, obesity, and diet contamination. Genetic alterations and genomic instability, probably resulted from unrepaired DNA lesions, are increasingly recognized as a common feature of human HCC. Dysregulation of DNA damage repair and signaling to cell cycle checkpoints, known as the DNA damage response (DDR), is associated with a predisposition to cancer and affects responses to DNA-damaging anticancer therapy. It has been demonstrated that various HCC-associated risk factors are able to promote DNA damages, formation of DNA adducts, and chromosomal aberrations. Hence, alterations in the DDR pathways may accumulate these lesions to trigger hepatocarcinogenesis and also to facilitate advanced HCC progression. This review collects some of the most known information about the link between HCC-associated risk factors and DDR pathways in HCC. Hopefully, the review will remind the researchers and clinicians of further characterizing and validating the roles of these DDR pathways in HCC.

Tetrandrine induces mitochondria-mediated apoptosis in human gastric cancer BGC-823 cells

Tetrandrine, a bis-benzylisoquinoline alkaloid isolated from the dried root of Hang-Fang-Chi (Stephaniatetrandra S. Moore), has been reported to possess anti-cancer effects on many tumors. In this study, we investigated tetrandrine-induced apoptosis on human gastric cancer BGC-823 cells in vitro and in vivo. The results showed that tetrandrine significantly inhibited cell viability in a dose- and time-dependent manner and induced apoptosis. It increased the apoptosis; upregulation of Bax, Bak, and Bad; and downregulation of Bcl-2 and Bcl-xl in BGC-823 cells. Moreover, tetrandrine increased the activation of caspase-3 and -9, release of cytochrome c, and upregulation of apaf-1, suggesting that tetrandrine-induced apoptosis was related to the mitochondrial pathway. Meanwhile, pretreatment with the pan-caspase inhibitor z-VAD-fmk in BGC-823 cells reduced tetrandrine-induced apoptosis by blocking activation of caspases. Furthermore, tetrandrine effectively inhibited tumor growth via apoptosis induction, which was verified by immunohistochemical analysis in a nude mouse xenograft model. Taken together, we concluded that tetrandrine significantly inhibited the proliferation of gastric cancer BGC-823 cells through mitochondria-dependent apoptosis, which may play a promising role in gastric cancer therapy.

Synthesis and antitumor activity of tetrandrine derivatives

Tetrandrine possesses antitumor activity, however, only a few studies on its structure modification were reported. To improve the antitumor activity of tetrandrine, 20 new tetrandrine derivatives were designed and synthesized by Sonogashira and Suzuki reactions. Their antitumor activities were evaluated against three tumor cell lines including A549, HepG2, and BGC-823 by methyl thiazolyl tetrazolium assay with taxol as a positive control. The results showed that compounds 2c and 2g were highly potent against BGC-823 cell line, and compounds 1i and 1k showed particular activity against HepG2 cells. These results demonstrated that compounds 1i, 1k, 2c, and 2g were promising leads for further investigation.

Tetrandrine citrate eliminates imatinib-resistant chronic myeloid leukemia cells in vitro and in vivo by inhibiting Bcr-Abl/β-catenin axis

OBJECTIVE

To evaluate the effects of tetrandrine citrate, a novel tetrandrine salt with high water solubility, on the growth of imatinib (IM)-resistant chronic myeloid leukemia (CML) in vitro and in vivo, and reveal action molecular mechanisms.

METHODS

Cell viability in vitro was measured using methyl thiazolyl tetrazolium (MTT) assay. CML cell growth in vivo was assessed using a xenograft model in nude mice. Bcr-Abl and β-catenin protein levels were determined using Western blotting. Bcr-Abl messenger RNA (mRNA) was measured by reverse transcription polymerase chain reaction (RT-PCR). Flow cytometry (FCM) was used to determine cell cycle status.

RESULTS

Tetrandrine citrate inhibited the growth of IM-resistant K562 cells, primary leukemia cells, and primitive CD34(+) leukemia cells, and their inhibition concentration that inhibited 50% of target cells (IC(50)) ranged from 1.20 to 2.97 μg/ml. In contrast, tetrandrine citrate did not affect normal blood cells under the same conditions, and IC(50) values were about 10.12-13.11 μg/ml. Oral administration of tetrandrine citrate caused complete regression of IM-resistant K562 xenografts in nude mice without overt toxicity. Western blot results revealed that treatment of IM-resistant K562 cells with tetrandrine citrate resulted in a significant decrease of both p210(Bcr-Abl) and β-catenin proteins, but IM did not affect the Bcr-Abl protein levels. Proteasome inhibitor, MG132, did not prevent tetrandrine-mediated decrease of the p210(Bcr-Abl) protein. RT-PCR results showed that tetrandrine treatment caused a decrease of Bcr-Abl mRNA. FCM analysis indicated that tetrandrine induced gap 1 (G(1)) arrest in CML cells.

CONCLUSIONS

Tetrandrine citrate is a novel orally active tetrandrine salt with potent anti-tumor activity against IM-resistant K562 cells and CML cells. Tetrandrine citrate-induced growth inhibition of leukemia cells may be involved in the depletion of p210(Bcr-Abl) mRNA and β-catenin protein.

Tetrandrine Suppresses Cancer Angiogenesis and Metastasis in 4T1 Tumor Bearing Mice

Metastasis remains the most deadly aspect of cancer and still evades direct treatment. Thus, there is a great need to develop new treatment regimens to suppress tumor cells that have escaped surgical removal or that may have already disseminated. We have found that tetrandrine (TET) exhibits anticolon cancer activity. Here, we investigate the inhibition effect of TET to breast cancer metastasis, angiogenesis and its molecular basis underlying TET's anticancer activity. We compare TET with chemotherapy drug doxorubicin in 4T1 tumor bearing BALB/c mice model and find that TET exhibits an anticancer metastatic and antiangiogenic activities better than those of doxorubicin. The lung metastatic sites were decreased by TET, which is confirmed by bioluminescence imaging in vivo. On the other hand, laser doppler perfusion imaging (LDI) was used for measuring the blood flow of tumor in 4T1-tumor bearing mice. As a result, the local blood perfusion of tumor was markedly decreased by TET after 3 weeks. Mechanistically, TET treatment leads to a decrease in p-ERK level and an increase in NF-κB levels in HUVECs. TET also regulated metastatic and angiogenic related proteins, including vascular endothelial growth factor, hypoxia-inducible factor-1α, integrin β5, endothelial cell specific molecule-1, and intercellular adhesion molecule-1 in vivo.

Tetrandrine inhibits hepatocellular carcinoma cell growth through the caspase pathway and G2/M phase

Activation of p53-independent pathways plays an important role in phytochemical-induced apoptosis and is considered to be a crucial factor in the invasion and metastasis of cancer. Previous studies have shown that combined effects of Stephania tetrandra with medicinal herbs exhibit beneficial effects in cancer patients. Tetrandrine, an active component of Stephania tetrandra has been reported to have anticancer properties in cancer cells. However, the mechanism(s) of action of tetrandrine in liver cancer have yet to be fully elucidated. In this study, we investigated the effects of tetrandrine in hepatocellular carcinoma (HCC) cells. The results showed that tetrandrine inhibited HCC cell proliferation by suppression of cell cycle progression at the G2/M phase. Changes in the expression levels of Bax, Bcl, p53, survivin, PCNA, PARP and p21 were observed. In addition, tetrandrine increased caspase-3 expression and induced DNA fragmentation in Huh-7 cells. The results suggest that the anti-cancer effect of tetrandrine in Huh-7 cells may be mediated by p53-independent pathways.

Silencing of APE1 enhances sensitivity of human hepatocellular carcinoma cells to radiotherapy in vitro and in a xenograft model

Resistance to radiotherapy is a key limitation for the treatment of human hepatocellular carcinoma (HCC). To overcome this problem, we investigated the correlation between radioresistance and the human apurinic/apyrimidinic endonuclease (APE1), a bifunctional protein, which plays an important role in DNA repair and redox regulation activity of transcription factors. In the present study, we examined the radiosensitivity profiles of three human HCC cell lines, HepG2, Hep3B, and MHCC97L, using the adenoviral vector Ad5/F35-mediated APE1 siRNA (Ad5/F35-siAPE1). The p53 mutant cell lines MHCC97L showed radioresistance, compared with HepG2 and Hep3B cells. APE1 was strongly expressed in MHCC97L cells and was induced by irradiation in a dose-dependent manner, and Ad5/F35-siAPE1 effectively inhibited irradiation-induced APE1 and p53 expression. Moreover, silencing of APE1 significantly potentiated the growth inhibition and apoptosis induction by irradiation in all tested human HCC cell lines. In addition, Ad5/F35-siAPE1 significantly enhanced inhibition of tumor growth and potentiated cell apoptosis by irradiation both in HepG2 and MHCC97L xenografts. In conclusion, down regulation of APE1 could enhance sensitivity of human HCC cells to radiotherapy in vitro and in vivo.

Alkaloids isolated from natural herbs as the anticancer agents

Alkaloids are important chemical compounds that serve as a rich reservoir for drug discovery. Several alkaloids isolated from natural herbs exhibit antiproliferation and antimetastasis effects on various types of cancers both in vitro and in vivo. Alkaloids, such as camptothecin and vinblastine, have already been successfully developed into anticancer drugs. This paper focuses on the naturally derived alkaloids with prospective anticancer properties, such as berberine, evodiamine, matrine, piperine, sanguinarine, and tetrandrine, and summarizes the mechanisms of action of these compounds. Based on the information in the literature that is summarized in this paper, the use of alkaloids as anticancer agents is very promising, but more research and clinical trials are necessary before final recommendations on specific alkaloids can be made.

Tetrandrine, a Compound Common in Chinese Traditional Medicine, Preferentially Kills Breast Cancer Tumor Initiating Cells (TICs) In Vitro

Tetrandrine is a bisbenzylisoquinoline alkaloid found in Stephania tetrandra, a Chinese medicine commonly used as an anti-inflammatory. It has extensive pharmacological activity, including positive ion channel blockade and inhibition of multiple drug resistance proteins. These activities are very similar to that of salinomycin, a known drug targeting breast cancer initiation cells (TICs). Herein, we tested tetrandrine targeting of breast cancer TICs. SUM-149, an inflammatory breast cancer cell line and SUM-159, a non-inflammatory metaplastic breast cancer cell line were used in these studies. In proliferation assays using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), we found that the IC₅₀ for inhibition of proliferation is 15.3 ± 4.1 μM for SUM-149 and 24.3 ± 2.1 μM for SUM-159 cells. Tetrandrine also inhibited mammosphere formation, a surrogate for breast cancer TICs growth in vitro with IC₅₀ around 1 μM for SUM-149 and around 2 μM for SUM-159 cells. Tetrandrine has similar effects on the mammosphere formation from cells isolated from fresh patient sample. Moreover, tetrandrine decreases the aldehyde dehydrogenase (ALDH) positive population in SUM-159 by 45% ± 5.45% P = 0.005. In summary, tetrandrine demonstrates significant efficacy against in vitro surrogates for inflammatory and aggressive breast cancer TICs.

Radiation-induced intercellular signaling mediated by cytochrome-c via a p53-dependent pathway in hepatoma cells

The tumor suppressor p53 has a crucial role in cellular response to DNA damage caused by ionizing radiation, but it is still unclear whether p53 can modulate radiation-induced bystander effects (RIBE). In the present work, three different hepatoma cell lines, namely HepG2 (wild p53), PLC/PRF/5 (mutation p53) and Hep3B (p53 null), were irradiated with γ-rays and then co-cultured with normal Chang liver cell (wild p53) in order to elucidate the mechanisms of RIBE. Results showed that the radiosensitivity of HepG2 cells was higher than that of PLC/PRF/5 and Hep3B cells. Only irradiated HepG2 cells, rather than irradiated PLC/PRF/5 or Hep3B cells, could induce bystander effect of micronuclei (MN) formation in the neighboring Chang liver cells. When HepG2 cells were treated with 20 μM pifithrin-α, an inhibitor of p53 function, or 5 μM cyclosporin A (CsA), an inhibitor of cytochrome-c release from mitochondria, the MN induction in bystander Chang liver cells was diminished. In fact, it was found that after irradiation, cytochrome-c was released from mitochondria into the cytoplasm only in HepG2 cells in a p53-dependent manner, but not in PLC/PRF/5 and Hep3B cells. Interestingly, when 50 μg/ml exogenous cytochrome-c was added into cell co-culture medium, RIBE was significantly triggered by irradiated PLC/PRF/5 and Hep3B cells, which previously failed to provoke a bystander effect. In addition, this exogenous cytochrome-c also partly recovered the RIBE induced by irradiated HepG2 cells even with CsA treatment. Our results provide new evidence that the RIBE can be modulated by the p53 status of irradiated hepatoma cells and that a p53-dependent release of cytochrome-c may be involved in the RIBE.

Tetrandrine induces apoptosis and triggers caspase cascade in human bladder cancer cells

BACKGROUND

Tetrandrine is known to exert anti-tumor effects, however, little is known about its effect on human bladder carcinoma. In this study, employing two different human bladder cancer cell lines, 5637 and T24, which represent high-risk superficial bladder cancer (5637) and high-grade bladder cancer (T24), we tested tetrandrine-induced apoptosis and growth inhibition in bladder carcinoma cell lines and investigated the possible mechanisms.

MATERIALS AND METHODS

Growth inhibition and apoptosis induction was determined by MTT assay and flow cytometry analysis, respectively. Activation of caspases were analyzed by Western blotting and caspase colorimetric assay. The collapse of mitochondrial membrane potential (ΔΨ(m)) and subcellular distribution of cytochrome c was determined by JC-1 staining and Western blotting, respectively.

RESULTS

Tetrandrine treatment showed strong growth inhibitory and apoptotic effects on human bladder cancer 5637 and T24 cells in a concentration-dependent manner. Additionally, induction of apoptosis by tetrandrine was associated with a very strong and prominent caspase-9, caspase-8, and caspase-3 activation as well as PARP cleavage. Flow cytometric studies revealed that tetrandrine induced a dose-dependent loss of ΔΨ(m), which was accompanied by the release of cytochrome c from mitochondria to the cytosol.

CONCLUSION

Taken together, this study provided the first evidence that tetrandrine imparted inhibitory and apoptotic activity in human bladder cancer cells. The tetrandrine-induced apoptosis might be related to the activation of the caspase cascade and mitochondrial pathway. Our results suggest that tetrandrine merits further in vivo investigation as a novel bladder cancer chemopreventive and chemotherapeutic agent in the clinical setting.

Proteomic analysis of anti-tumor effects by tetrandrine treatment in HepG2 cells

Tetrandrine (TET), a bis-benzylisoquinoline alkaloid isolated from the root of Hang-Fang-Chi (Stephenia tetrandra S Moore), exhibits broad pharmacological effects, including anti-tumor activity. Recently, the beneficial effects of TET on cytotoxicity towards tumor cells, radiosensitization, circumventing multidrug resistance, normal tissue radioprotection, and antiangiogenesis have been examined extensively. To explore the potential molecular mechanism of the anti-tumor effect of TET, we applied proteomic tools to profile the proteins in HepG2 cells subjected to TET treatment. The levels of 39 proteins in cells exposed to TET (IC₅₀=5±0.6 μg/ml) for 48 h were observed to undergo significant alterations. Six proteins were identified by matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) using peptide fingerprinting from 10 protein spots (density difference >1.5-fold between the control and TET-treated group). Among them, 5 proteins were downregulated (proteasome activator complex subunit 3, 40S ribosomal protein S12, phosphoglycerate mutase 1, destrin, transaldolase) and 1 protein was upregulated (guanylate kinase 1) by TET treatment in HepG2 cells as determined by spot volume (P<0.05). Most of the identified proteins were associated with tumor growth, migration, and anti-tumor drug resistance. These data will be helpful in elucidating the molecular mechanism of TET's anti-tumor effect in HepG2 cells.

Tetrandrine inhibits Wnt/β-catenin signaling and suppresses tumor growth of human colorectal cancer

As one of the most common malignancies, colon cancer is initiated by abnormal activation of the Wnt/β-catenin pathway. Although the treatment options have increased for some patients, overall progress has been modest. Thus, there is a great need to develop new treatments. We have found that bisbenzylisoquinoline alkaloid tetrandrine (TET) exhibits anticancer activity. TET is used as a calcium channel blocker to treat hypertensive and arrhythmic conditions in Chinese medicine. Here, we investigate the molecular basis underlying TET's anticancer activity. We compare TET with six chemotherapy drugs in eight cancer lines and find that TET exhibits comparable anticancer activities with camptothecin, vincristine, paclitaxel, and doxorubicin, and better than that of 5-fluorouracil (5-FU) and carboplatin. TET IC₅₀ is ≤5 μM in most of the tested cancer lines. TET exhibits synergistic anticancer activity with 5-FU and reduces migration and invasion capabilities of HCT116 cells. Furthermore, TET induces apoptosis and inhibits xenograft tumor growth of colon cancer. TET treatment leads to a decrease in β-catenin protein level in xenograft tumors, which is confirmed by T-cell factor/lymphocyte enhancer factor and c-Myc reporter assays. It is noteworthy that HCT116 cells with allelic oncogenic β-catenin deleted are less sensitive to TET-mediated inhibition of proliferation, viability, and xenograft tumor growth. Thus, our findings strongly suggest that the anticancer effect of TET in colon cancer may be at least in part mediated by targeting β-catenin activity. Therefore, TET may be used alone or in combination as an effective anticancer agent.

CWJ-081, a novel 3-arylisoquinoline derivative, induces apoptosis in human leukemia HL-60 cells partially involves reactive oxygen species through c-Jun NH2-terminal kinase pathway

In the present study, we investigated the effect of a novel 3-arylisoquinoline derivative 3-(6-ethyl-benzo[1,3]dioxol-5-yl)-7,8-dimethoxy-2-methyl-2H-isoquinolin-1-one (CWJ-081) on the induction of apoptosis and the putative molecular mechanism of its action in human leukemia cells. Treatment with CWJ-081 exhibited a characteristic feature of apoptosis including externalization of phosphatidylserine and formation of DNA fragmentation in human leukemia cell lines (HL-60, U-937, K-562). In addition, stimulation of HL-60 cells with CWJ-081 induced a series of intracellular events: (1) the activations of caspase-8, -9, and -3; (2) the cleavage of poly (ADP-ribose) polymerase-1 (PARP-1); (3) the loss of mitochondrial membrane potential (ΔΨ(m)); (4) the release of cytochrome c; and (5) the modulation of Bcl-2 family proteins. We further demonstrated that CWJ-081 induces reactive oxygen species (ROS) production and c-Jun NH(2)-terminal kinase (JNK) activation. Pretreatment with the antioxidant N-acetyl-L-cysteine (NAC) markedly inhibited the CWJ-081-induced JNK activation and apoptosis. Moreover, CWJ-081-induced apoptosis was suppressed in the presence of SP600125, a specific JNK inhibitor. Taken together, these data suggest that CWJ-081 induces apoptosis via the mitochondrial apoptotic pathway in HL-60 cells, and ROS-mediated JNK activation plays a key role in the CWJ-081-induced apoptosis.

Tetrandrine ameliorated reperfusion injury of small bowel transplantation

PURPOSE

In small bowel transplantation, the bowel graft is susceptible to reperfusion injury. This study investigated the effects of tetrandrine, a bisbenzylisoquinoline alkaloid, on the development of intestinal reperfusion injury in small bowel transplantation in pigs.

MATERIALS AND METHODS

Pigs underwent small bowel transplantation and were treated with tetrandrine or a vehicle. Blood and small bowel specimens were harvested at 1, 3, and 24 hours after reperfusion. Histopathologic analysis of the small bowel was assessed for tissue damage. Serum levels of tumor necrosis factor-alpha, interleukin-1beta (IL-1beta), and IL-6 were measured by enzyme-linked immunosorbent assay. Reverse-transcriptase polymerase chain reaction analysis was performed to analyze the expression of proinflammatory cytokines, and immunohistochemical analysis was used to study the expression of intercellular adhesion molecule-1 (ICAM-1) in the small bowel. Myeloperoxidase staining detected neutrophil infiltration in the small bowel and the number of myeloperoxidase positively stained cells was counted.

RESULTS

Pigs receiving small bowel transplantation had elevated serum proinflammatory cytokine levels. The transplanted small bowel showed mucosal damage, increased expression of proinflammatory cytokines and ICAM-1, and prominent neutrophil infiltration. Tetrandrine administration reduced mucosal damage, serum and tissue proinflammatory cytokine levels, ICAM-1 expression, and neutrophil accumulation in the transplanted small bowel.

CONCLUSIONS

Tetrandrine reduced the reperfusion injury in porcine intestinal transplantation during the first 24 hours after the procedure.

Gastric antisecretory and antiulcer activities of Cyclea peltata (Lam.) Hook. f. & Thoms. in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Cyclea peltata (Lam.) Hook. f. & Thoms. (Menispermaceae), locally called 'Padathaali/Padakizhangu' is used in Ayurvedic medicine to treat peptic ulcer.

AIM OF THE STUDY

To evaluate the gastric antisecretory and antiulcer activity of Cyclea peltata.

MATERIALS AND METHODS

The ethanolic extract of Cyclea peltata root was used to evaluate its gastric antisecretory and antiulcer effect in the pylorus-ligated rat model and gastric lesions induced by ethanol or ethanol and indomethacin respectively in rats. The levels of gastric wall mucus, non-protein sulfhydryl groups (NP-SH), malondialdehyde, protein and catalase activity in the stomach samples of Cyclea peltata treated and control groups of rats were also quantified.

RESULTS

The ethanolic extract of Cyclea peltata roots showed significant antisecretory activity as evidenced by decreased pepsin secretion, gastric juice volume and acid output in pylorus-ligated rats. Pretreatment with Cyclea peltata extract provided significant protection against the peptic ulceration caused by ethanol administered individually, or in combination with indomethacin. Our studies also revealed that pretreatment with Cyclea peltata significantly increased the gastric protein and catalase concentration of ethanol treated rats. Further, it showed significant gastroprotective effects on the stomach wall of ethanol or ethanol and indomethacin treated rats by decreasing malondialdehyde level, increasing the gastric wall mucus and non-protein sulfhydryl groups.

CONCLUSION

The present findings demonstrate that Cyclea peltata ethanolic extract has potent antisecretory and antiulcer effects and justify the traditional/ethnic usage of this herb to treat peptic ulcers and consequent stomach ache.

Potential role of ginseng in the treatment of colorectal cancer

Colorectal cancer remains one of the most prevalent cancer and a leading cause of cancer related death in the US. Many currently used chemotherapeutic agents are derived from botanicals. Identifying herbal sources, including those from ginseng family, to develop better anti-cancer therapies remains an essential step in advancing the treatment of the cancer. In this article, potential roles of ginseng herbs, especially American ginseng and notoginseng, in colorectal cancer therapeutics are presented. The major pharmacologically active constituents of ginsengs are ginsenosides, which can be mainly classified as protopanaxadiol and protopanaxatriol groups. Structure-activity relationship between their chemical structures and pharmacological activities are discussed. In addition, various steaming temperature and time treatment of the ginseng herbs can change ginsenoside profiles, and enhance their anti-cancer activities. This heat treatment process may increase the role of ginseng in treating colorectal cancer.

Tetrandrine ameliorates dextran-sulfate-sodium-induced colitis in mice through inhibition of nuclear factor -kappaB activation

BACKGROUND

Activation of nuclear factor (NF)-kappaB has been shown to play a critical role in the pathogenesis of ulcerative colitis (UC), and tetrandrine, a bisbenzylisoquinoline alkaloid isolated from the Chinese herb Radix Stephania tetrandra, has been demonstrated to be a potent inhibitor of NF-kappaB activation. The purpose of the study was to investigate effects of tetrandrine on experimental model of UC.

MATERIALS AND METHODS

Tetrandrine was administered in experimental colitis induced by dextran sulfate sodium (DSS). The disease activity index (DAI) and histological score were observed. NF-kappaB DNA binding activity was assessed by electrophoretic mobility shift assay. The expression of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta were measured by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay.

RESULTS

A significant improvement was observed in DAI and histological score in mice with tetrandrine, and the increase in NF-kappaB DNA binding activity, myeloperoxidase activity, IL-1beta, and TNF-alpha in mice with DSS-induced colitis was significantly reduced following administration of tetrandrine.

CONCLUSION

The administration of tetrandrine leads to an amelioration of DSS-induced colitis, suggesting administration of tetrandrine may provide a therapeutic approach for UC.

Evaluation of the genotoxicity of piplartine, an alkamide of Piper tuberculatum, in yeast and mammalian V79 cells

The genus Piper belongs to the Piperaceae family, and includes species of commercial and medicinal importance. Chemical studies on Piper species resulted in the isolation of several biologically active molecules, including alkaloid amides, such as piplartine. This molecule, isolated from Piper tuberculatum, has significant cytotoxic activity against tumor cell lines, and presents antifungal, anti-platelet aggregation, anxiolytic, and antidepressant effects. In order to understand the biological properties of piplartine, this study investigated the genotoxicity and the induction of apoptosis by piplartine in V79 cells and its mutagenic and recombinogenic potential in Saccharomyces cerevisiae. Piplartine induced dose-dependent cytotoxicity in S. cerevisiae cultures in either stationary -- or exponential growth phase. In addition, piplartine was not mutagenic when cells were treated during exponential-growth phase and kept in buffer solution, but it increased the frequencies of point, frameshift, and forward mutations when cells were treated in medium during growth. Piplartine treatment induced DNA strand breaks in V79 cells, as detected by neutral and alkaline comet assay. In cell cycle analysis, piplartine induced G2/M cell cycle arrest, probably as a consequence of the DNA damage induced and repair. Moreover, piplartine treatment induced apoptosis in a dose-dependent manner, as observed by a decrease in mitochondrial membrane potential and an increase in internucleosomal DNA fragmentation. These data suggest that the DNA damage caused by piplartine induces G2/M cell cycle arrest, followed by apoptosis. Moreover, we suggest that cells surviving piplartine-induced DNA damage can accumulate mutations, since this alkaloid was mutagenic and recombinogenic in S. cerevisiae assays.

Effects of tetrandrine on apoptosis and radiosensitivity of nasopharyngeal carcinoma cell line CNE

Tetrandrine is known to exert antitumor effect, however, little is known about its effect on nasopharyngeal carcinoma cells. In this study, we tested tetrandrine-induced apoptosis and radiosensitivity in nasopharyngeal carcinoma cell line CNE and investigated the possible mechanisms. Using flow cytometry and DNA electrophoresis, we found that tetrandrine could induce cell apoptosis. Further, it was shown that the level of Bcl-2 mRNA decreased and Bax mRNA increased after addition of tetrandrine by using reverse transcription-polymerase chain reaction. X-ray-induced G2 arrest was abrogated by treatment with tetrandrine, as detected by flow cytometry and mitotic index. The accumulation of cyclinB1 protein and the suppression of Cdc2 tyrosine-15 and Cdc25C serine-216 phosphorylation were detected in irradiated cells treated with tetrandrine using Western blot analysis. Taken together, these results show that tetrandrine can induce apoptosis and abrogate radiation-induced G2 arrest in CNE cells.