Chemotherapy is a mainstay of cancer treatment. Due to increased drug resistance and the severe side effects of currently used therapeutics, new candidate compounds are required for improvement of therapy success. Shikonin, a natural naphthoquinone, was used in traditional Chinese medicine for the treatment of different inflammatory diseases and recent studies revealed the anticancer activities of shikonin. We found that shikonin has strong cytotoxic effects on 15 cancer cell lines, including multidrug-resistant cell lines. Transcriptome-wide mRNA expression studies showed that shikonin induced genetic pathways regulating cell cycle, mitochondrial function, levels of reactive oxygen species, and cytoskeletal formation. Taking advantage of the inherent fluorescence of shikonin, we analyzed its uptake and distribution in live cells with high spatial and temporal resolution using flow cytometry and confocal microscopy. Shikonin was specifically accumulated in the mitochondria, and this accumulation was associated with a shikonin-dependent deregulation of cellular Ca2+ and ROS levels. This deregulation led to a breakdown of the mitochondrial membrane potential, dysfunction of microtubules, cell-cycle arrest, and ultimately induction of apoptosis. Seeing as both the metabolism and the structure of mitochondria show marked differences between cancer cells and normal cells, shikonin is a promising candidate for the next generation of chemotherapy.

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We investigate the martensitic transition of single crystalline Ni 2 MnGa͑110͒ /Al 2 O 3 ͑1120͒ and Ni 2 MnGa͑100͒ /MgO͑100͒ films using magnetometry, x-ray diffraction, x-ray absorption spectroscopy, and x-ray magnetic circular dichroism. The martensitic transition from the cubic austenite phase to the low symmetry martensite phase depends strongly on the chosen substrate. For ͑110͒ oriented films on Al 2 O 3 , the martensitic phase is significantly more stable than for the ͑100͒ oriented films on MgO. A remarkable change of the Ni x-ray absorption spectra occurs at the transition, indicating specific changes of the electronic structure. The observed changes are in agreement with theoretical predictions. The orbital to spin momentum ratio of the Ni moment increases significantly on entering the martensite state, thus explaining the macroscopic increase of magnetic anisotropy.

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Development of novel therapy strategies is one of the major pressing topics of clinical oncology to overcome drug resistance of tumors. Artesunate (ART) is an anti-malarial drug, which also exerts profound cytotoxic activity towards cancer cells. We applied a gene-hunting approach using microarray-based transcriptome-wide mRNA expression profiling and COMPARE analyses. We identified a set of genes, whose expression was associated either with high IC50 values or low IC50 values for ART. Therefore, these genes may function as resistance or sensitivity factors for response of tumor cells towards ART. This viewpoint is conceivable for genes involved in ribosomal activity, drug transport, cellular antioxidant defense, apoptosis, cell proliferation, cell cycle progression etc. An investigation of underlying signal transduction by pathway analysis suggested a role of the signaling pathways related to tumor necrosis factor (TNF) and the tumor suppressor p53. On the other hand, there were genes without obvious functional link to cellular response to ART, such as genes involved in the survival of cochlear outer and inner hair cells etc. We proved the hypothesis that ART influences the activity of transcription factors regulating downstream genes involved or not involved in response of cancer cells towards ART. This would explain the identification of genes with and without obvious relation to the cytotoxic activity of ART by microarray and COMPARE analyses. By analysis of the binding motifs for the transcription factors c-Myc and Max, we indeed found that 53 of 56 genes contained one or more binding sites for c-Myc/Max upstream of the gene-location. We conclude that c-Myc and Max-mediated transcriptional control of gene expression might contribute to the therapeutic effects of ART in cancer cells, but may also confer unwanted side effects by affecting therapy-unrelated genes.

BackgroundMalignant diseases are responsible of approximately 13% of all deaths each year in the world. Natural products represent a valuable source for the development of novel anticancer drugs. The present study was aimed at evaluating the cytotoxicity of a naphtyl butanone isolated from the leaves of Guiera senegalensis, guieranone A (GA).ResultsThe results indicated that GA was active on 91.67% of the 12 tested cancer cell lines, the IC50 values below 4 μg/ml being recorded on 83.33% of them. In addition, the IC50 values obtained on human lymphoblastic leukemia CCRF-CEM (0.73 μg/ml) and its resistant subline CEM/ADR5000 (1.01 μg/ml) and on lung adenocarcinoma A549 (0.72 μg/ml) cell lines were closer or lower than that of doxorubicin. Interestingly, low cytotoxicity to normal hepatocyte, AML12 cell line was observed. GA showed anti-angiogenic activity with up to 51.9% inhibition of the growth of blood capillaries on the chorioallantoic membrane of quail embryo. Its also induced apotosis and cell cycle arrest. Ingenuity Pathway Analysis identified several pathways in CCRF-CEM cells and functional group of genes regulated upon GA treatment (P < 0.05), the Cell Cycle: G2/M DNA Damage Checkpoint Regulation and ATM Signaling pathways being amongst the four most involved functional groups.ConclusionThe overall results of this work provide evidence of the cytotoxic potential of GA and supportive data for its possible use in cancer chemotherapy.

Abstract:In recent years, the popularity increased for nutritional supplements and herbal products. Prescription drugs, but not herbal therapies are paid by health insurances. They are sold over-the-counter (OTC) on the patients' own expense. However, there are potential risks of self-medication, e.g. incorrect self-diagnosis, severe adverse reactions, dangerous drug interactions, risk of addiction etc. They are often used by patients at their own discretion without knowledge of and control by their physicians. Certain users are at risk of intoxication. Multiple medications taken by older patients increase the risk for adverse drug reactions, drug-drug interactions, and compliance problems for this age group (polypharmacy). Herbals should be discontinued prior to operations to avoid interactions with anesthetics or anticoagulants. Herbal preparations may also be carcinogenic or interfere with cancer treatments. Pregnant women use various OTC preparations. However, in many cases, it is unclear whether their use is safe for mother or baby. Self-medication with herbals is also largely distributed among anxious and depressive patients, and patients with other conditions and symptoms. The popularity of herbal products has also brought concerns on quality, efficacy and safety. Cases of botanical misidentification, contaminations with heavy metals, pesticides, radioactivity, organic solvents, microbials as well as adulteration with chemical drugs necessitate the establishment of international quality control standards. Hepatotoxic effects have been reported for more than 300 plant species, and some commonly used herbs have been demonstrated to interact with Western medication. Health care professionals have a critical responsibility assessing the self-care ability of their patients. Databases are available for pharmacists with information on action, side effects and toxicities as well as herb-drug interactions. There is a need for established guidelines regarding the correct use of nutritional supplements and herbal OTC preparations (phytovigilance). Physicians, pharmacists, and other health care professionals have to counsel patients and the general public on the benefits and risks associated with herbal drugs. Information centers for consumers and general practitioners are needed, and convincing evidence on safety and efficacy of herbal products has to be demonstrated in placebo-controlled, double blind and randomized clinical trials.

Scrophularia ningpoensis has been used in China for centuries as a herbal tea to treat various diseases. Based on the numerous animal studies on its pharmaceutical effects and the long time clinical experiences, we studied the molecular and cellular mechanism underlying the bioactivity of aqueous extract of Scrophularia and its isolated compounds. Seven isolated compounds, unlike Scrophularia extract, failed to induce cytotoxicity on HaCaT cells, but their combination improved the effect of extract. Tumor cell line selectivity was not observed, when we studied its cytotoxic effect on melanoma cell lines. The apoptotic and anti-inflammatory effects of Scrophularia extract have been demonstrated on HaCaT cells. The extract induced those effects potentially through affecting the MAPK pathway and inhibition of the NF-κB pathway, Microarray-based bioinformatical analyses on the compound acetoside from Scrophularia revealed a gene expression profile which confirmed our findings with the extract on proliferation inhibition, anti-inflammation and apoptosis. With DNA alkylation as major proposed mechanism of action, we assume acetoside as one of the active compounds in Scrophularia.