Dihydroartemisinin (DHA) induces caspase-3-dependent apoptosis in human lung adenocarcinoma ASTC-a-1 cells

Dietary supplementation with dihydroartemisinin improves intestinal barrier function in weaned piglets with intrauterine growth retardation by modulating the gut microbiota

The aim of this study was to investigate whether dietary dihydroartemisinin (DHA) supplementation could improve intestinal barrier function and microbiota composition in intrauterine growth restriction (IUGR) weaned piglets. Twelve normal birth weight (NBW) piglets and 24 IUGR piglets at 21 d of age were divided into three groups, which were fed a basal diet (NBW-CON and IUCR-CON groups) and an 80 mg/kg DHA diet (IUGR-DHA group). At 49 d of age, eight piglets of each group with similar body weights within groups were slaughtered, and serum and small intestine samples were collected. The results showed that IUGR piglets reduced growth performance, impaired the markers of intestinal permeability, induced intestinal inflammation, decreased intestinal immunity, and disturbed the intestinal microflora. Dietary DHA supplementation increased average daily gain, average daily feed intake, and body weight at 49 d of age in IUGR-weaned piglets (P < 0.05). DHA treatment decreased serum diamine oxidase activity and increased the numbers of intestinal goblet cells and intraepithelial lymphocytes, concentrations of jejunal mucin-2 and ileal trefoil factor 3, and intestinal secretory immunoglobin A and immunoglobin G (IgG) concentrations of IUGR piglets (P < 0.05). Diet supplemented with DHA also upregulated mRNA abundances of jejunal IgG, the cluster of differentiation 8 (CD8), major histocompatibility complex-I (MHC-I), and interleukin 6 (IL-6) and ileal IgG, Fc receptor for IgG (FcRn), cluster of differentiation 8 (CD4), CD8, MHC-I, IL-6 and tumor necrosis factor α (TNF-α), and enhanced mRNA abundance and protein expression of intestinal occludin and ileal claudin-1 in IUGR piglets (P < 0.05). In addition, DHA supplementation in the diet improved the microbial diversity of the small intestine of IUGR piglets and significantly increased the relative abundance of Actinobacteriota, Streptococcus, Blautia and Streptococcus in the jejunum, and Clostridium sensu_ stricto_in the ileum (P < 0.05). The intestinal microbiota was correlated with the mRNA abundance of tight junction proteins and inflammatory response-related genes. These data suggested that DHA could improve the markers of intestinal barrier function in IUGR-weaned piglets by modulating gut microbiota. DHA may be a novel nutritional candidate for preventing intestinal dysfunction in IUGR pigs.

Himalayan flora: targeting various molecular pathways in lung cancer

The fatal amplification of lung cancer across the globe and the limitations of current treatment strategies emphasize the necessity for substitute therapeutics. The incorporation of phyto-derived components in chemo treatment holds promise in addressing those challenges. Despite the significant progressions in lung cancer therapeutics, the complexities of molecular mechanism and pathways underlying this disease remain inadequately understood, necessitating novel biomarker targeting. The Himalayas, abundant in diverse plant varieties with established chemotherapeutic potential, presents a promising avenue for investigating potential cures for lung carcinoma. The vast diversity of phytocompounds herein can be explored for targeting the disease. This review delves into the multifaceted targets of lung cancer and explores the established phytochemicals with their specific molecular targets. It emphasizes comprehending the intricate pathways that govern effective therapeutic interventions for lung cancer. Through this exploration of Himalayan flora, this review seeks to illuminate potential breakthroughs in lung cancer management using natural compounds. The amalgamation of Himalayan plant-derived compounds with cautiously designed combined therapeutic approaches such as nanocarrier-mediated drug delivery and synergistic therapy offers an opportunity to redefine the boundaries of lung cancer treatment by reducing the drug resistance and side effects and enabling an effective targeted delivery of drugs. Furthermore, additional studies are obligatory to understand the possible derivation of natural compounds used in current lung cancer treatment from plant species within the Himalayan region.

Mitochondria-Targeted COUPY Photocages: Synthesis and Visible-Light Photoactivation in Living Cells

Releasing bioactive molecules in specific subcellular locations from the corresponding caged precursors offers great potential in photopharmacology, especially when using biologically compatible visible light. By taking advantage of the intrinsic preference of COUPY coumarins for mitochondria and their long wavelength absorption in the visible region, we have synthesized and fully characterized a series of COUPY-caged model compounds to investigate how the structure of the coumarin caging group affects the rate and efficiency of the photolysis process. Uncaging studies using yellow (560 nm) and red light (620 nm) in phosphate-buffered saline medium have demonstrated that the incorporation of a methyl group in a position adjacent to the photocleavable bond is particularly important to fine-tune the photochemical properties of the caging group. Additionally, the use of a COUPY-caged version of the protonophore 2,4-dinitrophenol allowed us to confirm by confocal microscopy that photoactivation can occur within mitochondria of living HeLa cells upon irradiation with low doses of yellow light. The new photolabile protecting groups presented here complement the photochemical toolbox in therapeutic applications since they will facilitate the delivery of photocages of biologically active compounds into mitochondria.

Dihydroartemisinin enhances the anti-tumor activity of oxaliplatin in colorectal cancer cells by altering PRDX2-reactive oxygen species-mediated multiple signaling pathways

BACKGROUND

Globally, colorectal cancer (CRC) is one of the leading causes of cancer-related deaths. Oxaliplatin based treatments are frequently used as chemotherapeutic methods for CRC, however, associated side effects and drug resistance often limit their clinical application. Dihydroartemisinin (DHA) induces apoptosis in various cancer cells by increasing reactive oxygen species (ROS) production. However, the direct target of DHA and underlying molecular mechanisms in oxaliplatin-mediated anti-tumor activities against CRC are unclear.

METHODS

We used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), flow cytometry, and colony formation assays to investigate cell phenotype alterations and ROS generation. We also used quantitative Real-Time PCR (qRT-PCR) and western blotting to measure relative gene and protein expression. Finally, an in vivo mouse xenograft model was used to assess the anti-tumor activity of oxaliplatin and DHA alone, and combinations.

RESULTS

DHA synergistically enhanced the anti-tumor activity of oxaliplatin in colon cancer cells by regulating ROS-mediated ER stress, signal transducer and activator of transcription 3 (STAT3), C-Jun-amino-terminal kinase (JNK), and p38 signaling pathways. Mechanistically, DHA increased ROS levels by inhibiting peroxiredoxin 2 (PRDX2) expression, and PRDX2 knockdown sensitized DHA-mediated cell growth inhibition and ROS production in CRC cells. A mouse xenograft model showed strong anti-tumor effects from combination treatments when compared with single agents.

CONCLUSIONS

We demonstrated an improved therapeutic strategy for CRC patients by combining DHA and oxaliplatin treatments.

Perspectives and controversies regarding the use of natural products for the treatment of lung cancer

Lung cancer is the leading cause of cancer‐related mortality both in men and women and accounts for 18.4% of all cancer‐related deaths. Although advanced therapy methods have been developed, the prognosis of lung cancer patients remains extremely poor. Over the past few decades, clinicians and researchers have found that chemical compounds extracted from natural products may be useful for treating lung cancer. Drug formulations derived from natural compounds, such as paclitaxel, doxorubicin, and camptothecin, have been successfully used as chemotherapeutics for lung cancer. In recent years, hundreds of new natural compounds that can be used to treat lung cancer have been found through basic and sub‐clinical research. However, there has not been a corresponding increase in the number of drugs that have been used in a clinical setting. The probable reasons may include low solubility, limited absorption, unfavorable metabolism, and severe side effects. In this review, we present a summary of the natural compounds that have been proven to be effective for the treatment of lung cancer, as well as an understanding of the mechanisms underlying their pharmacological effects. We have also highlighted current controversies and have attempted to provide solutions for the clinical translation of these compounds.

The Therapeutic Effects of Dihydroartemisinin on Cisplatin-Resistant Gastric Cancer Cells

BACKGROUND

Dihydroartemisinin (DHA) exhibited anti-tumor effect in a variety of cancer cells but its mechanism of action is unclear.

OBJECTIVE

To investigate the therapeutic effects of DHA on Cisplatin (DDP)-resistant gastric cancer cell strain SGC7901/DDP and the possible molecular mechanism.

METHODS

Cells were treated with DHA in dose- and time-dependent manners, after which their proliferation, apoptosis, invasion and migration abilities were evaluated. We further evaluated autophagy with mRFP-GFP-LC3 adenovirus transfection and transmission electron microscopy, and also detected the expression levels of proteins (related to autophagy and apoptosis) via western blot. Meanwhile, the influence of DHA on cisplatin resistance was detected through a sensitization test and the evaluation of P-gp expression levels.

RESULTS

DHA effectively inhibited the proliferation, invasion, and migration of SGC7901/DDP cells and induced cell apoptosis which was accompanied by caspase-8/9/3 activation. Furthermore, exposure of DHA resulted in a pronounced increase in autophagy proteins including Beclin-1 and LC3 II with PI3K/AKT/mTOR pathway inhibition. Additionally, enhancement of cisplatin sensitivity occurred in SGC7901/DDP cells treated with DHA, which was accompanied by P-gp downregulation.

CONCLUSION

DHA exerts an anti-cancer effect on SGC7901/DDP cells and the mechanisms possibly include enhancement of autophagy via PI3K/AKT/mTOR inhibition, inducement of apoptosis through caspase-dependent and mitochondrial pathway, and enhancement of cisplatin sensitivity through P-gp inhibition.

Ferroptosis: A Novel Mechanism of Artemisinin and its Derivatives in Cancer Therapy

BACKGROUND

Artemisinin is a sesquiterpene lactone compound with a special peroxide bridge that is tightly linked to the cytotoxicity involved in fighting malaria and cancer. Artemisinin and its derivatives (ARTs) are considered to be potential anticancer drugs that promote cancer cell apoptosis, induce cell cycle arrest and autophagy, inhibit cancer cell invasion and migration. Additionally, ARTs significantly increase intracellular Reactive Oxygen Species (ROS) in cancer cells, which result in ferroptosis, a new form of cell death, depending on the ferritin concentration. Ferroptosis is regarded as a cancer suppressor and as well as considered a new mechanism for cancer therapy.

METHODS

The anticancer activities of ARTs and reference molecules were compared by literature search and analysis. The latest research progress on ferroptosis was described, with a special focus on the molecular mechanism of artemisinin-induced ferroptosis.

RESULTS

Artemisinin derivatives, artemisinin-derived dimers, hybrids and artemisinin-transferrin conjugates, could significantly improve anticancer activity, and their IC50 values are lower than those of reference molecules such as doxorubicin and paclitaxel. The biological activities of linkers in dimers and hybrids are important in the drug design processes. ARTs induce ferroptosis mainly by triggering intracellular ROS production, promoting the lysosomal degradation of ferritin and regulating the System Xc-/Gpx4 axis. Interestingly, ARTs also stimulate the feedback inhibition pathway.

CONCLUSION

Artemisinin and its derivatives could be used in the future as cancer therapies with broader applications due to their induction of ferroptosis. Meanwhile, more attention should be paid to the development of novel artemisinin-related drugs based on the mechanism of artemisinininduced ferroptosis.

YM155, specific survivin inhibitor, can enhance artesunate-induced cytotoxicity in HCT116 colon cancer cells

Purpose

A water-soluble variant of the artemisinin called artesunate, approved as an antimalarial agent, can induce cell death on various cancer cell types. We studied the mechanism of cell death of artesunate on HCT116 colorectal cancer cells.

Methods

We treated HCT116 colon cancer cells with artesunate, holo-transferrin, deferoxamine mesylate, ferrostatin, necrostatin-1, and YM155. We observed the growth inhibition of artesunate on HCT116 colon cancer cells by morphologic findings. Inhibition of cell growth was assessed by MTT (3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide) assay and long-term growth inhibition by colony-forming assay. Apoptosis was investigated by flow cytometry and Western blot analysis.

Results

Artesunate inhibited the proliferation of HCT116 colon cancer cells effectively. Co-treatment with YM155, a specific survivin inhibitor, enhanced the artesunate-induced cell death. Co-treatment with the iron-chelating agent deferoxamine rescued artesunate induced cell death and increased long-term cell survival and proliferation.

Conclusion

In this study, we demonstrated that artesunate-induced cytotoxicity in HCT116 colon cancer cells by suppressing the expression of survivin and partially by ferroptosis. Our findings suggest that the co-treatment artesunate with YM155 can induce more potent cell death on HCT116 colon cancer cells and shows new insight for the treatment of colorectal cancer patients.

Eliminating Radiation Resistance of Non-Small Cell Lung Cancer by Dihydroartemisinin Through Abrogating Immunity Escaping and Promoting Radiation Sensitivity by Inhibiting PD-L1 Expression

Radiation resistance is linked to immune escaping and radiation sensitivity. In this study, we found that the PD-L1 expressions of non-killed tumor cells in NSCLC were enhanced after radiotherapy, and dihydroartemisinin (DHA) could synergistically enhance the antitumor effect of radiotherapy in NSCLC. A total of 48 NSCLC patients with sufficient tumor tissues for further analyses were enrolled. The PD-L1 expressions of NSCLC were evaluated by immunohistochemistry. Cell apoptosis was measured by flow cytometry, and the relationship between the PD-L1 expression and radiation resistance was investigated in patient specimens, xenograft model, and cell lines. First, the results indicate that the PD-L1 expression of NSCLC was positively related with the radiation resistance. Second, we found that DHA could eliminate the radiation resistance and synergistically enhance the antitumor effect of radiotherapy in the NSCLC cells lines and xenograft model. Finally, mechanistically, DHA could inhibit the PD-L1 expression to avoid immune escaping by inhibiting TGF-β, PI3K/Akt, and STAT3 signaling pathways. In addition, DHA could activate TRIM21 and regulate the EMT-related proteins by inhibiting the PD-L1 so as to enhance the radiation sensitivity and eliminate radiation resistance to NSCLC. Collectively, this study established a basis for the rational design of integrated radiotherapy and DHA for the treatment of NSCLC.

Comparison of the cytotoxic effects of different fractions of Artemisia ciniformis and Artemisia biennis on B16/F10, PC3 and MCF7 Cells

Background and purpose:

Artemisia is one of the well-known herbal medicinal plants for antimicrobial, insecticidal, antioxidant, and antimalarial activities. The antiproliferative effects of dichloromethane extracts of Artemisia biennis (A. biennis) and A. ciniformis and the petroleum ether extract of A. ciniformis have been demonstrated previously on human cancerous cell lines. In the current study, further fractionation was carried out on the aforementioned extracts and their cytotoxic effects were evaluated on three human cancer cell lines; B16/F10, PC3, and MCF7. F1 to F16, F1’ to F11’, and F1” to F10” were resulted from the fractionation of dichloromethane extracts of A. biennis, A. ciniformis, and petroleum ether extract of A. ciniformis, respectively.

Experimental approach:

The cytotoxic effects of 16 (F1-F16), 11 (F1’-F11’) and 10 (F1”-F10”) fractions, on B16/F10, PC3, and MCF7 cell lines were assessed using resazurin to measure viability and propidium iodide staining (sub G1) and flow cytometry to detect apoptosis.

Findings / Results:

The results showed that, some fractions at 100 μg/mL decreased cell viability. F2” in B16/F10 cells, F2, F4-F6, F10’, F11’, and F2” in PC3 cells, and F10’, F11’, and F2” in MCF7 significantly decreased cell viability in a concentration-dependent manner (12.5-50 μg/mL). Among different fractions, F2” demonstrated the most potent cytotoxic effects on cancer cell lines (P < 0.001). All of the mentioned fractions (except F11’ on PC3 cells) increased the number of apoptotic cells and showed the cytotoxic effects on cancer cells compared with the control group.

Conclusion and implications:

A. biennis and A. ciniformis are suggested as the potential sources of cytotoxic phytochemicals. The probable presence of terpenoids, steroids, and alkaloids in the selected fractions is proposed based on the preliminary phytochemical study.

Artemisinins as a novel anti-cancer therapy: Targeting a global cancer pandemic through drug repurposing

Artemisinins are a unique class of antimalarial drugs with significant potential for drug repurposing for a wide range of diseases including cancer. Cancer is a leading cause of death globally and the majority of cancer related deaths occur in Low and Middle Income Countries (LMICs) where conventional treatment options are often limited by financial cost. Drug repurposing can significantly shorten new therapeutic discovery pathways, ensuring greater accessibility and affordability globally. Artemisinins have an excellent safety and tolerability profile as well as being affordable for deployment in Low and Middle Class Income Countries at around USD1 per daily dose. Robust, well designed clinical trials of artemisinin drug repurposing are indicated for a variety of different cancers and treatment settings.

Antibacterial Photodynamic Treatment of Porphyromonas gingivalis with Toluidine Blue O and a NonLaser Red Light Source Enhanced by Dihydroartemisinin

In vitro experiments confirmed that antibacterial photodynamic treatment (aPDT) inactivates periodontal pathogens. However, more effective sterilization is needed in the complex oral environment. This study tested whether dihydroartemisinin (DHA) enhanced the photokilling effect of aPDT on Porphyromonas gingivalis (P. gingivalis) in planktonic and biofilm states. aPDT combining toluidine blue O (TBO) with 630 nm red light was performed on bacterial suspensions and biofilms in vitro with different final concentrations of DHA (10, 20 and 40 μg mL^-1 ). The sensitization mechanism was preliminarily investigated by uptake experiments. The above experiments were repeated with different incubation times (30, 60, 120 s). Porphyromonas gingivalis biofilms exhibited significantly higher resistance to aPDT than P. gingivalis in suspension under the same experimental parameters. DHA alone had no cytotoxic effect on P. gingivalis with or without light irradiation. In either bacterial suspensions or biofilms, DHA concentration-dependently enhanced the photokilling effect of aPDT and increased TBO uptake by P. gingivalis. Prolonged incubation time enhanced the photokilling efficiency of aPDT until cellular TBO uptake reached saturation. DHA can enhance aPDT activity against P. gingivalis in planktonic and biofilm states. DHA also accelerated TBO uptake, reducing incubation time.

Artemisinin and its derivatives: a promising cancer therapy

The world is experiencing a cancer epidemic and an increase in the prevalence of the disease. Cancer remains a major killer, accounting for more than half a million deaths annually. There is a wide range of natural products that have the potential to treat this disease. One of these products is artemisinin; a natural product from Artemisia plant. The Nobel Prize for Medicine was awarded in 2015 for the discovery of artemisinin in recognition of the drug's efficacy. Artemisinin produces highly reactive free radicals by the breakdown of two oxygen atoms that kill cancerous cells. These cells sequester iron and accumulate as much as 1000 times in comparison with normal cells. Generally, chemotherapy is toxic to both cancerous cells and normal cells, while no significant cytotoxicity from artemisinin to normal cells has been found in more than 4000 case studies, which makes it far different than conventional chemotherapy. The pleiotropic response of artemisinin in cancer cells is responsible for growth inhibition by multiple ways including inhibition of angiogenesis, apoptosis, cell cycle arrest, disruption of cell migration, and modulation of nuclear receptor responsiveness. It is very encouraging that artemisinin and its derivatives are anticipated to be a novel class of broad-spectrum antitumor agents based on efficacy and safety. This review aims to highlight these achievements and propose potential strategies to develop artemisinin and its derivatives as a new class of cancer therapeutic agents.

Emerging role of phytochemicals in targeting predictive, prognostic, and diagnostic biomarkers of lung cancer

Lung-cancer is the foremost cause of cancer in humans worldwide, of which 80-85% cases are composed of non-small cell lung carcinoma. All treatment decisions depend on the pattern of biomarkers selection to enhance the response to the targeted therapies. Although advanced treatments are available for lung-cancer, the disease treatment remains not adequate. There are several synthetic chemotherapeutic agents available for the treatment of lung cancer. However, due to their toxic effect, survival rate is still 15-18%. Besides, medicinal plants are a huge reservoir of natural products that provide protective effects against lung cancer. Likewise, successful studies of potential phytochemicals in targeting lung-cancer biomarkers have created a novel paradigm for the discovery of potent drugs against lung-cancer. Hence, to defeat severe toxicity and resistance towards the synthetic drugs, detailed studies are required regarding the available phytochemicals and targets responsible for the treatment of lung-cancer. The present review provides a comprehensive information about the lung-cancer biomarkers under the classification of predictive, prognostic, and diagnostic type. Moreover, it discusses and enlists the phytochemicals with mode of action against different biomarkers, effective doses in in vitro, in vivo, and clinical studies, the limitations associated with usage of phytochemicals as a drug to prevent/cure lung-cancer and the latest techniques employed to overcome such issues.

Anti-malarial drug, artemisinin and its derivatives for the treatment of respiratory diseases

Artemisinins are sesquiterpene lactones with a peroxide moiety that are isolated from the herb Artemisia annua. It has been used for centuries for the treatment of fever and chills, and has been recently approved for the treatment of malaria due to its endoperoxidase properties. Progressively, research has found that artemisinins displayed multiple pharmacological actions against inflammation, viral infections, and cell and tumour proliferation, making it effective against diseases. Moreover, it has displayed a relatively safe toxicity profile. The use of artemisinins against different respiratory diseases has been investigated in lung cancer models and inflammatory-driven respiratory disorders. These studies revealed the ability of artemisinins in attenuating proliferation, inflammation, invasion, and metastasis, and in inducing apoptosis. Artemisinins can regulate the expression of pro-inflammatory cytokines, nuclear factor-kappa B (NF-κB), matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF), promote cell cycle arrest, drive reactive oxygen species (ROS) production and induce Bak or Bax-dependent or independent apoptosis. In this review, we aim to provide a comprehensive update of the current knowledge of the effects of artemisinins in relation to respiratory diseases to identify gaps that need to be filled in the course of repurposing artemisinins for the treatment of respiratory diseases. In addition, we postulate whether artemisinins can also be repurposed for the treatment of COVID-19 given its anti-viral and anti-inflammatory properties.

TMT-based proteomics analysis of the anti-hepatocellular carcinoma effect of combined dihydroartemisinin and sorafenib

Hepatocellular carcinoma (HCC), as the major primary liver cancer, is one of the most prevalent malignant diseases with a high mortality rate worldwide. Prior studies have demonstrated that dihydroartemisinin (DHA), the semisynthetic derivative of artemisinin, possesses anti-HCC activity. The multikinase inhibitor sorafenib has been approved for the treatment of HCC. However, the anti-HCC efficacy of DHA combined with sorafenib has not been reported. In this study, we confirmed the significantly enhanced anti-HCC efficacy of DHA in combination with sorafenib compared with that of each agent alone. Tandem Mass Tag (TMT) peptide labeling coupled with LC-MS/MS was used to quantify the proteins from the control, DHA, sorafenib, and DHA + sorafenib groups. In total, 532, 426, 628 differentially expressed proteins (fold change >1.20 or <0.83 and P-value <0.05) were determined by comparing DHA versus control, sorafenib versus control and DHA + sorafenib versus control groups, respectively. Moreover, optimized screening was performed, and 101 optimized differentially expressed proteins were identified. The results of functional analysis of the optimized differentially expressed proteins suggested that they were enriched in cell components such as membrane-bound vesicles, extracellular vesicles, and organelle lumens, and they were mainly involved in biological processes such as cellular component organization, response to stress, and response to chemicals; in addition, they were related to various molecular functions such as protein binding, chromatin binding and enzyme binding. KEGG pathway analysis showed that the optimized differentially expressed proteins were enriched in pyrimidine metabolism, RNA polymerase, base excision repair, and osteoclast differentiation. Protein-protein interaction (PPI) networks of some of the optimized upregulated proteins suggested that they might not only affect vitamin and fat digestion and absorption but may also be involved in tight junctions. In the PPI network, some of the optimized downregulated proteins were enriched in base excision repair, RNA polymerase, purine metabolism, pyrimidine metabolism and mucin type O-glycan biosynthesis. Overall, this research explored the anti-HCC efficacy of DHA combined with sorafenib by using the TMT-based quantitative proteomics technique and might facilitate the understanding of the related anti-HCC molecular mechanism.

Hydrogen Peroxide Mediates Artemisinin-Derived C-16 Carba-Dimer-Induced Toxicity of Human Cancer Cells

This study used a nitroaliphatic chemistry approach to synthesize a novel artemisinin-derived carba-dimer (AG-1) and determined its anti-proliferative effects in human normal and cancer cells. AG-1 treatments selectively inhibit proliferation of cancer cells compared to normal human fibroblasts. Compared to artemisinin, AG-1 is more toxic to human breast, prostate, head–neck, pancreas and skin cancer cells; 50% inhibition (IC₅₀) 123 µM in AG-1 vs. 290 µM in artemisinin-treated breast cancer cells. AG-1 treatment decreased (~5 folds) cyclin D1 protein expression that correlated with an increase in the percentage of cells in the G₁-phase, suggesting a G₁ delay. AG-1-induced toxicity was independent of the DNA damage at 72 h post-treatment, as measured by micronuclei frequency and γH2AX protein levels. Results from electron paramagnetic resonance spectroscopy showed Fe-catalyzed formation of AG-1 carbon-centered radicals in a cell-free system. Flow cytometry analysis of H₂DCF-DA oxidation showed a significant increase in the steady-state levels of reactive oxygen species (ROS) in AG-1-treated cells. Pre-treatment with N-acetyl-l-cysteine and antioxidant enzymes (superoxide dismutase and catalase) significantly suppressed AG-1-induced toxicity, suggesting that superoxide and hydrogen peroxide contribute to AG-1-induced toxicity in human cancer cells. AG-1 represents a novel class of anti-cancer drug that is more potent than its parent compound, artemisinin.

Drug Repurposing in the Development of Anticancer Agents

BACKGROUND

Research into repositioning known drugs to treat cancer other than the originally intended disease continues to grow and develop, encouraged in part, by several recent success stories. Many of the studies in this article are geared towards repurposing generic drugs because additional clinical trials are relatively easy to perform and the drug safety profiles have previously been established.

OBJECTIVE

This review provides an overview of anticancer drug development strategies which is one of the important areas of drug restructuring.

METHODS

Repurposed drugs for cancer treatments are classified by their pharmacological effects. The successes and failures of important repurposed drugs as anticancer agents are evaluated in this review.

RESULTS AND CONCLUSION

Drugs could have many off-target effects, and can be intelligently repurposed if the off-target effects can be employed for therapeutic purposes. In cancer, due to the heterogeneity of the disease, often targets are quite diverse, hence a number of already known drugs that interfere with these targets could be deployed or repurposed with appropriate research and development.

Vitisin B as a novel fatty acid synthase inhibitor induces human breast cancer cells apoptosis

Breast cancer is one of the most common cancers and the second leading cause of cancer mortality in women worldwide. Novel therapies and chemo-therapeutic drugs are still in urgent need to be developed for the treatment of breast cancer. One of the most important metabolic hallmarks of breast cancer cells is enhanced lipogenesis. Increasing evidences suggest that fatty acid synthase (FAS) plays an important role in the development of human breast cancer, for the expression of FAS is significantly higher in breast cancer cells than in normal cells. In addition, FAS inhibitors, such as curcumin, ursolic acid, and resveratrol, have shown anti-cancer potential. In the present study, we discovered that vitisin B, a natural stilbene isolated from the seeds of Iris lactea Pall. var. chinensis (Fisch.), was a novel FAS inhibitor. We found that vitisin B could down-regulate FAS expression and inhibit intracellular FAS activity in MDA-MB-231 cells. Also, we reported for the first time that vitisin B exhibited apoptotic effect on human breast cancer cells. Given all of this, we proposed a hypothesis that vitisin B has an application potential in the chemoprevention and treatment of breast cancer.

Analysis of the Essential Oils of Five Artemisia Species and Evaluation of their Cytotoxic and Proapoptotic Effects

BACKGROUND

In this study, the essential oil composition and cytotoxic activities of five Artemisia species were determined.

METHODS

The collected plants were water-distilled separately to obtain oils which were then subjected to gas chromatography (GC) and gas chromatography/mass spectrometry GC/MS analyses to identify their compositions. Cancer cells were exposed to different concentrations of samples and cell viability was measured using AlamarBlue® assay. Apoptotic cells were analyzed by propidium iodide (PI) staining and flow cytometry.

RESULTS & CONCLUSION

To study the amount of pro-apoptotic proteins and the apoptosis mechanism, Western blot method was used. Although all samples were cytotoxic at the highest concentration, the oil of A. kulbadica showed the strongest activity among other plants. Carvacrol (IC50 21.11 μg/ml) had the most cytotoxic effects among other components. Carvacrol, 1,8-cineole and 4-terpineole caused an increase in the amount of Bax protein and cleaved peroxisome proliferator-activated receptors (PPAR) and caspase proteins in DU 145 cells.

Intracellular catalase activity instead of glutathione level dominates the resistance of cells to reactive oxygen species

Artesunate (ARS) induced significant reactive oxygen species (ROS) generation in HepG2, HeLa, and A549 lines. However, ARS induced ROS-dependent apoptosis in HeLa and A549 cell lines but ROS-independent apoptosis in HepG2 cells. A total of 200 μM hydrogen peroxide (H2O2) significantly induced cytotoxicity in HeLa cells, while H2O2 up to 300 μM did not induce cytotoxicity in HepG2 cells, further demonstrating the strong resistance of HepG2 cells to ROS. HeLa cells had much higher basic total glutathione (T-GSH) level than HepG2 cells, while the ratio of basic reduced glutathione (GSH)/oxidized glutathione (GSSG) in HepG2 cells was nearly twice than that in HeLa and A549 cells. Inhibition of glutathione markedly enhanced H2O2- or ARS-induced cytotoxicity in HeLa and A549 cell lines but modestly enhanced the cytotoxicity of H2O2 and even did not affect the cytotoxicity of ARS in HepG2 cells. Moreover, addition of GSH remarkably prevented H2O2- or ARS-induced cytotoxicity in HeLa and A549 cell lines, further indicating the involvement of GSH in scavenging ROS in the two cell lines. HepG2 cells exhibited higher catalase activity than HeLa cells, and inhibiting catalase activity by using 3-aminotriazole (3-AT, a specific inhibition of catalase) or catalase siRNA remarkably reduced the resistance of HepG2 cells to ROS, demonstrating the key roles of catalase for the strong resistance of HepG2 cells to ROS. Collectively, catalase activity instead of glutathione level dominates the resistance of cells to ROS.

Organelle-Targeted BODIPY Photocages: Visible-Light-Mediated Subcellular Photorelease

Photocaging facilitates non-invasive and precise spatio-temporal control over the release of biologically relevant small- and macro-molecules using light. However, sub-cellular organelles are dispersed in cells in a manner that renders selective light-irradiation of a complete organelle impractical. Organelle-specific photocages could provide a powerful method for releasing bioactive molecules in sub-cellular locations. Herein, we report a general post-synthetic method for the chemical functionalization and further conjugation of meso-methyl BODIPY photocages and the synthesis of endoplasmic reticulum (ER)-, lysosome-, and mitochondria-targeted derivatives. We also demonstrate that 2,4-dinitrophenol, a mitochondrial uncoupler, and puromycin, a protein biosynthesis inhibitor, can be selectively photoreleased in mitochondria and ER, respectively, in live cells by using visible light. Additionally, photocaging is shown to lead to higher efficacy of the released molecules, probably owing to a localized and abrupt release.

Determining survival fractions of Saccharomyces cerevisiae in response to ionizing radiation in liquid culture

Saccharomyces cerevisiae survival fractions (SFs) in response to X-ray radiation were determined by two new methods: an OD600-based method and a 96-well method. For the OD600-based method, cells were exposed to various X-ray doses and inoculated into fresh medium: a lower biomass accumulated, indicating fewer surviving cells within the investigated dose range (0-100 Gy). For the 96-well method, diluent containing ~0-100 cells was equally divided into 96 droplets and respectively inoculated into 96 wells containing 200 μl of broth: fewer wells without S. cerevisiae clones indicated more surviving cells after 48 h of incubation. Corresponding quantitative systems were established. Both methods were sensitive and reliable. The OD600-based method is simple and fast, and the 96-well method simplifies the counting process. SF estimates by the OD600-based method were lower than those by 96-well methods owing to cell cycle arrest. In addition, comparisons of newly proposed and plate-counting methods indicated a higher rate of repair in S. cerevisiae in liquid culture than on agar.

Upstream regulators of apoptosis mediates methionine-induced changes of lipid metabolism

Although the role of methionine (Met), as precursor for l-carnitine synthesis, in the regulation of lipid metabolism has been explored. Met seems to have tissue- and species-specific regulatory effect on lipid metabolism, implying that the mechanisms in Met regulation of lipid metabolism is complex and may involve the upstream regulatory pathway of lipid metabolism. The present study was performed to determine the mechanism of apoptosis signaling pathways mediating Met-induced changes of hepatic lipid deposition and metabolism in fish, and compare the differences of the mechanisms between the fish and mammals. By iTRAQ-based quantitative proteome analyses, we found that both dietary Met deficiency and excess evoked apoptosis signaling pathways, increased hepatic lipid deposition and caused aberrant hepatic lipid metabolism of yellow catfish Pelteobagrus fulvidraco. Using primary hepatocytes from P. fulvidraco, inhibition of caspase by Z-VAD-FMK blocked the apoptotic signaling pathways with a concomitant reversal of Met deficiency- and excess-induced increase of lipid deposition, indicating that apoptosis involved the Met-mediated changes of hepatic lipid metabolism. Moreover, we explored the roles of three upstream apoptotic signaling pathways (PI3K/AKT-TOR pathway, cAMP/PKA/CREB pathway and LKB1/AMPK-FOXO pathway) influencing hepatic lipid metabolism of P. fulvidraco. The three upstream pathways participated in apoptosis mediating Met-induced changes of lipid metabolism in P. fulvidraco. At last, HepG2 cell line was used to compare the similarities of mechanisms in apoptosis mediating Met-induced changes of lipid metabolism between fish and mammals. Although several slight differences existed, apoptosis mediated the Met-induced changes of lipid metabolism between fish and mammals. The present study reveals novel apoptosis-relevant signal transduction axis which mediates the Met-induced changes of lipid metabolism, which will help understand the mechanistic link between apoptosis and lipid metabolism, and highlight the importance of the evolutionary conservative apoptosis signaling axis in regulating Met-induced changes of hepatic lipid metabolism.

Dihydroartemisinin Induces Endoplasmic Reticulum Stress-Mediated Apoptosis in HepG2 Human Hepatoma Cells

Aims and Background

Previous studies showed that dihydroartemisinin (DHA) possessed antitumor activity in many human tumor cells through the induction of apoptosis. The aim of this study was to investigate the effects of DHA on apoptosis in the human hepatocellular carcinoma cell line HepG2 and the possible molecular mechanisms involved.

Methods

The inhibitory effect of DHA on HepG2 cells was measured by MTT assay. The percentage of apoptotic cells was detected by flow cytometry with double staining of fluorescein isothiocyanate-annexin V/propidium iodide. The intracellular production of reactive oxygen species (ROS) and intracellular Ca2+ concentration ([Ca2+]i) were detected by fluorescence spectrophotometry. Protein expression of GADD153, Bcl-2 and Bax in HepG2 cells was examined by Western blot and immunocytochemistry.

Results

DHA significantly inhibited proliferation of HepG2 cells in a dose- and time-dependent manner. The apoptosis rates in HepG2 cells treated with 0, 50, 100 and 200 mol/L DHA for 24 hours were 2.53 ± 0.88%, 24.85 ± 3.63%, 35.27 ± 5.92% and 48.53 ± 7.76%, respectively. Compared with the control group, DHA significantly increased ROS generation and [Ca2+]i level (P <0.05), with the generation of ROS preceding the increase in [Ca2+]i. An increase in GADD153 and Bax expression and a decrease in Bcl-2 were observed in DHA-treated cells. Pretreatment with the antioxidant N-acetylcysteine could attenuate the effects of DHA in the experiments.

Conclusion

DHA could inhibit proliferation and induce apoptosis in HepG2 cell lines through increasing the intracellular production of ROS and [Ca2+]i. Endoplasmic reticulum stress-induced apoptosis may contribute to this effect by regulating the expression of GADD153, proapoptotic Bax, and antiapoptotic Bcl-2.

MitoKATP channels promote the proliferation of hypoxic human pulmonary artery smooth muscle cells via the ROS/HIF/miR-210/ISCU signaling pathway

Previous results have indicated that mitochondrial ATP-sensitive potassium (mitoK_ATP) channels are associated with the hypoxic proliferation of pulmonary artery smooth muscle cells (PASMCs). However, the mechanism underlying the promotive effects of mitoK_ATP channels on cell proliferation in response to hypoxia remains unknown. mitoK_ATP channel opening results in a collapse of mitochondrial membrane potential and generation of mitochondrial reactive oxygen species (ROS). As hypoxia-inducible factor-1α (HIF-1α) is a critical oxygen sensor and major transcriptional regulator of the hypoxic adaptive response, the current study assessed whether mitoK_ATP opening contributes to the chronic proliferation of human PASMCs (hPASMCs) in collaboration with HIF-1α and its downstream targets under hypoxic conditions. The present study demonstrated that there was crosstalk between mitoK_ATP channels and HIF-1α signaling in PASMCs under hypoxic conditions. The results suggest that mitoK_ATP channels are involved in the proliferation of PASMCs during hypoxia through upregulation of the ROS/HIF/microRNA-210/iron-sulfur cluster protein signaling pathway.

Application of the Triazolization Reaction to Afford Dihydroartemisinin Derivatives with Anti-HIV Activity

Artemisinin and synthetic derivatives of dihydroartemisinin are known to possess various biological activities. Post-functionalization of dihydroartemisinin with triazole heterocycles has been proven to lead to enhanced therapeutic potential. By using our newly developed triazolization strategy, a library of unexplored fused and 1,5-disubstituted 1,2,3-triazole derivatives of dihydroartemisinin were synthesized in a single step. All these newly synthesized compounds were characterized and evaluated for their anti-HIV (Human Immunodeficiency Virus) potential in MT-4 cells. Interestingly; three of the synthesized triazole derivatives of dihydroartemisinin showed activities with half maximal inhibitory concentration (IC₅₀) values ranging from 1.34 to 2.65 µM.

The Glutaminase-1 Inhibitor 968 Enhances Dihydroartemisinin-Mediated Antitumor Efficacy in Hepatocellular Carcinoma Cells

Reprogrammed metabolism and redox homeostasis are potential targets of cancer therapy. Our previous study demonstrated that the kidney form of glutaminase (GLS1) is highly expressed in hepatocellular carcinoma (HCC) cells and can be used as a target for effective anticancer therapy. Dihydroartemisinin (DHA) increases intracellular reactive oxygen species (ROS) levels leading to cytotoxicity in cancer cells. However, the heterogeneity of cancer cells often leads to differing responses to oxidative lesions. For instance, cancer cells with high ratio of GSH/GSSG, a critical ROS scavenger, are resistant to ROS-induced cytotoxicity. We postulate that a combinatorial strategy firstly disrupting redox homeostasis followed by DHA might yield a profound antitumor efficacy. In this study, when HCC cells were treated with a GLS1 inhibitor 968, the ROS elimination capacity was significantly reduced in HCC cells, which rendered HCC cells but not normal endothelial cells more sensitive to DHA-mediated cytotoxicity. We further confirmed that this synergistic antitumor efficacy was mediated by excessive ROS generation in HCC cells. NAC, a ROS inhibitor, partly rescued the combinatorial cytotoxic effect of 968 and DHA. Given that GLS1 is a potential antitumor target and DHA has been safely used in clinic, our findings provide new insight into liver cancer therapy targeting glutamine metabolism combined with the ROS generator DHA, which can be readily translated into cancer clinical trials.

A mechanistic approach to anti-nociceptive potential of Artemisia macrocephala Jacquem

Background

Artemisia macrocephala Jacquem (A. macrocephala), locally known as “Tarkha”, is a perennial plant found abundantly in northern areas of Pakistan. It is widely used in traditional medicine to treat fever, pain, gastrointestinal disorders and diabetes. Till date, no published studies are available regarding the in-vivo antinociceptive potential of the crude extract and sub-fractions from the aerial parts of A. macrocephala.

Methods

Antinociceptive effects of the crude methanolic extract and its sub-fractions were assessed using experimental pain models, including chemical nociception induced by intraperitoneal acetic acid or subplantar formalin injection and thermal nociception like tail immersion test in-vivo.

Results

The administration of various doses of crude extract and its fractions showed a dose-dependent indomethacin like antinociceptive effect in acetic acid induced writhing, subplantar formalin injection animal model suggesting the involvement of central mechanism of pain inhibition. Moreover, the crude extract and sub-fractions, on tail flick model (thermal nociception) demonstrated the involvement of central mechanism and significantly increased the latency time to 66.54, 82.94 and 70.53 %. The antagonistic study proposed the possible involvement of opioid receptor using naloxone as non-selective antagonist. The pharmacologically active chloroform and ethyl acetate fractions were further subjected to column chromatography that lead to the isolation four compounds. These isolated compounds were then subjected to various spectroscopic techniques upon which they were confirmed to be one sterol and three flavonoid derivatives. These findings suggest that Artemisia macrocephala possesses peripheral and central analgesic potentials partially associated with opioid system that support its folkloric use for the management of pain. The isolated compounds are currently under investigation in our laboratory for analgesic activity and its possible mechanism of action.

Conclusion

The results in this study provide evidences that A. macrocrphala has anticonciceptive effects and can be used for treatment of pain in traditional therapies. This study opens a new channel for isolation of analgesic compounds from the specie that is used traditionally for the management of pain.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1114-0) contains supplementary material, which is available to authorized users.

Dual Regulation of Cell Death and Cell Survival upon Induction of Cellular Stress by Isopimara-7,15-Dien-19-Oic Acid in Cervical Cancer, HeLa Cells In vitro

The Fritillaria imperialis is an ornamental flower that can be found in various parts of the world including Iraq, Afghanistan, Pakistan, and the Himalayas. The use of this plant as traditional remedy is widely known. This study aims to unveil the anti-cancer potentials of Isopimara-7,15-Dien-19-Oic Acid, extracted from the bulbs of F. imperialis in cervical cancer cell line, HeLa cells. Flow cytometry analysis of cell death, gene expression analysis via cDNA microarray and protein array were performed. Based on the results, Isopimara-7,15-Dien-19-Oic acid simultaneously induced cell death and promoted cell survival. The execution of apoptosis was apparent based on the flow cytometry results and regulation of both pro and anti-apoptotic genes. Additionally, the regulation of anti-oxidant genes were up-regulated especially thioredoxin, glutathione and superoxide dismutase- related genes. Moreover, the treatment also induced the activation of pro-survival heat shock proteins. Collectively, Isopimara-7,15-Dien-19-Oic Acid managed to induce cellular stress in HeLa cells and activate several anti- and pro survival pathways.

Anti-cancer properties of a sesquiterpene lactone-bearing fraction from Artemisia khorassanica

BACKGROUND

Artemisia species are important medicinal plants throughout the world. The present in vitro study, using a sesquiterpene lactone-bearing fraction prepared from Artemisia khorassanica (SLAK), sought to investigate anti-cancer properties of this plant and elucidate potential underlying mechanisms for the effects.

MATERIALS AND METHODS

Anti-cancer potential was evaluated by toxicity against human melanoma and fibroblast cell lines. To explore the involved pathways, pattern of any cell death was determined using annexin-V/PI staining and also the expression of Bax and cytochrome c was investigated by Western blotting.

RESULTS

The results showed that SLAK selectively caused a concentration-related inhibition of proliferation of melanoma cells that was associated with remarkable increase in early events and over-expression of both Bax and cytochrome c.

CONCLUSIONS

The current experiment indicates that Artemisia may have anti-cancer activity. We anticipate that the ingredients may be employed as therapeutic candidates for melanoma.

Upregulation of the MCL-1S protein variant following dihydroartemisinin treatment induces apoptosis in cholangiocarcinoma cells

The aim of the present study was to determine whether dihydroartemisinin (DHA) induces apoptosis in the human cholangiocarcinoma QBC939 cell line through the regulation of myeloid cell leukemia-1 (MCL-1) expression. The inhibitory rates of DHA on QBC939 cell proliferation and the effects of DHA on the cell death rates at various DHA concentrations and following various treatment times were examined. The rate of apoptosis and cell cycle changes following DHA treatment were examined and the changes in the expression of MCL-1 mRNAs and MCL-1 proteins following DHA treatment were also examined. The MTT assay and trypan blue staining demonstrated that DHA significantly inhibited the proliferation (P<0.05) and promoted the death of QBC939 cells (P<0.05). The DNA ladder assay and flow cytometry (FCM) analysis demonstrated that the rate of apoptosis in the experimental group was significantly increased following DHA treatment (P<0.01). FCM analysis also demonstrated that DHA treatment led to a reduction in the percentage of QBC939 cells in the G₀/G₁ and G₂/M phases, and the majority of the DNA-treated cells were arrested in the S phase of the cell cycle (P<0.01). Western blot analysis demonstrated that DHA treatment significantly upregulated the expression of the pro-apoptotic MCL-1S protein. In contrast, no significant difference in the expression of the anti-apoptotic MCL-1L protein was observed following DHA treatment. DHA affected the expression of the apoptosis-associated protein MCL-1 through multiple mechanisms. DHA treatment increased the ratio of MCL-1S/MCL-1L protein, thus inducing apoptosis in cholangiocarcinoma cells.

Dihydroartemisinin inhibits the Raf/ERK/MEK and PI3K/AKT pathways in glioma cells

It has previously been reported that dihydroartemisinin (DHA) is an effective novel anticancer compound in a number of types of tumor cells. Previous studies have demonstrated the anticancer activity of DHA in gioma cells. However, its underlining mechanism remains unclear. In the present study, the anticancer activity of DHA was examined in the glioma cell lines BT325 and C6. Western blot analysis was also employed to determine the signaling pathway changes. It was demonstrated that DHA effectively inhibited cell growth and induced apoptosis in glioma cells. Moreover, western blot analysis indicated that DHA-induced apoptosis was accompanied by inactivation of the Raf/MEK/ERK and PI3K/AKT signaling pathways, in addition to the downregulation of anti-apoptotic proteins Mcl-1 and Bcl-2 expression levels.

Anticancer Effect of AntiMalarial Artemisinin Compounds

The anti-malarial drug artemisinin has shown anticancer activity in vitro and animal experiments, but experience in human cancer is scarce. However, the ability of artemisinins to kill cancer cells through a variety of molecular mechanisms has been explored. A PubMed search of about 127 papers on anti-cancer effects of antimalarials has revealed that this class of drug, including other antimalarials, have several biological characteristics that include anticancer properties. Experimental evidences suggest that artemisinin compounds may be a therapeutic alternative in highly aggressive cancers with rapid dissemination, without developing drug resistance. They also exhibit synergism with other anticancer drugs with no increased toxicity toward normal cells. It has been found that semisynthetic artemisinin derivatives have much higher antitumor activity than their monomeric counterparts via mechanisms like apoptosis, arrest of cell cycle at G₀/G₁, and oxidative stress. The exact mechanism of activation and molecular basis of these anticancer effects are not fully elucidated. Artemisinins seem to regulate key factors such as nuclear factor-kappa B, survivin, NOXA, hypoxia-inducible factor-1α, and BMI-1, involving multiple pathways that may affect drug response, drug interactions, drug resistance, and associated parameters upon normal cells. Newer synthetic artemisinins have been developed showing substantial antineoplastic activity, but there is still limited information regarding the mode of action of these synthetic compounds. In view of the emerging data, specific interactions with established chemotherapy need to be further investigated in different cancer cells and their phenotypes and validated further using different semisynthetic and synthetic artemisinin derivatives.

Resveratrol protects rabbit articular chondrocyte against sodium nitroprusside-induced apoptosis via scavenging ROS

This study aims to investigate the mechanism by which resveratrol (RV) prevents sodium nitroprusside (SNP)-induced chondrocyte apoptosis, which is a characteristic feature of osteoarthritis (OA). Rabbit articular chondrocytes were pre-incubated with 100 μM RV for 18 h before 1.5 mM SNP co-treatment for 6 h. Cell viability was evaluated by CCK-8. Annexin V/PI double staining and Hoechst 33258 staining were used to determine the fashion of SNP-induced chondrocytes death. Mitochondrial membrane potential (ΔΨm) was measured by using flow cytometry (FCM) with TMRM and Rhodamine 123 staining. Intracellular reactive oxygen species (ROS) and nitric oxide (NO) levels were confirmed by FCM analysis with DCFH-DA and DAF-FM DA staining. Cytoskeleton proteins of chondrocytes co-stained with Actin-Trakcer Green and Tubulin-Trakcer Red were validated by confocal microscopy. SNP induced time- and dose-dependent chondrocytes apoptosis with decline of ΔΨm, activation of caspases as well as cytoskeletal remodeling. SNP induced a significant induction of both ROS and NO. RV remarkably prevented SNP-induced ROS production and apoptosis as well as cytoskeletal remodeling, but did not prevent SNP-induced NO production. Pretreatment with NO scavengers did not significantly prevent SNP-induced apoptosis and cytoskeletal remodeling. SNP induces NO-independent ROS production which dominates rabbit articular chondrocyte apoptosis, and RV protects chondrocytes against SNP-induced apoptosis via scavenging ROS instead of NO.

Predicting cytotoxicity of complex mixtures in high cancer incidence regions of the Huai River Basin based on GC-MS spectrum with partial least squares regression

Complex mixture exposures, such as those associated with water sources, are an important issue in health risk assessment. This study assessed the cytotoxicity of chemical mixtures extracted from water sources in regions of the Huai River Basin with high cancer incidences and built statistical models of cytotoxicity based on pollution profiles that were measured with gas chromatography-mass spectrometry (GC-MS). Both surface and ground waters were collected from rural water sources of Shenqiu County, Henan Province of China from 2008 to 2011 and extracted with XAD-2 resigns. Cytotoxicity was evaluated with Chinese hamster ovary K1 (CHO-K1) cells and compared against the pollution profiles of the extracts. IC50 of water samples ranged from 0.023 to 0.338L-eq/mL. The pollutants in waters determined by GC-MS are complex and some of the compounds that contributed to cytotoxicity lack toxicity data. A partial least squares (PLS) regression model of cytotoxicity was built based on linear aggregation of predictor variables (i.e., peaks for single compounds in the gas chromatograms). The PLS model contains 2 PLS factors extracted from 141 variables. The model was validated internally with training data permutation and externally with a test sample. The model explained 92% of the cytotoxicity in the training samples and 40% in the test sample. This approach provides a general, rapid method for relating water toxicity to GC-MS chromatograms and for predicting the compounds that contribute most to toxicity.

Mutual action of anticancer and antiparasitic drugs: are there any shared targets?

ABSTRACT 

Parasites and cancers have some common features. It has been shown that some parasites interfere with tumor growth. In addition, they both have common antigens such as the Tn antigen. A communal action of anticancer and antiparasitic drugs has been reported. This shared action may be related to common targets for these drugs in cancers and parasites. In this paper, mutual action of anticancer and antiparasitic drugs, with the aim of discussing shared targets of these drugs, has been reviewed.

Alpha-mangostin inhibits intracellular fatty acid synthase and induces apoptosis in breast cancer cells

Background

Fatty acid synthase (FAS) has been proven over-expressed in human breast cancer cells and consequently, has been recognized as a target for breast cancer treatment. Alpha-mangostin, a natural xanthone found in mangosteen pericarp, has a variety of biological activities, including anti-cancer effect. In our previous study, alpha-mangostin had been found both fast-binding and slow-binding inhibitions to FAS in vitro. This study was designed to investigate the activity of alpha-mangostin on intracellular FAS activity in FAS over-expressed human breast cancer cells, and to testify whether the anti-cancer activity of alpha-mangostin may be related to its inhibitory effect on FAS.

Methods

We evaluated the cytotoxicity of alpha-mangostin in human breast cancer MCF-7 and MDA-MB-231 cells. Intracellular FAS activity was measured by a spectrophotometer at 340 nm of NADPH absorption. Cell Counting Kit assay was used to test the cell viability. Immunoblot analysis was performed to detect FAS expression level, intracellular fatty acid accumulation and cell signaling (FAK, ERK1/2 and AKT). Apoptotic effects were detected by flow cytometry and immunoblot analysis of PARP, Bax and Bcl-2. Small interfering RNA was used to down-regulate FAS expression and/or activity.

Results

Alpha-mangostin could effectively suppress FAS expression and inhibit intracellular FAS activity, and result in decrease of intracellular fatty acid accumulation. It could also reduce cell viability, induce apoptosis in human breast cancer cells, increase in the levels of the PARP cleavage product, and attenuate the balance between anti-apoptotic and pro-apoptotic proteins of the Bcl-2 family. Moreover, alpha-mangostin inhibited the phosphorylation of FAK. However, the active forms of AKT, and ERK1/2 proteins were not involved in the changes of FAS expression induced by alpha-mangostin.

Conclusions

Alpha-mangostin induced breast cancer cell apoptosis by inhibiting FAS, which provide a basis for the development of xanthone as an agent for breast cancer therapy.