Linagliptin Protects against Endotoxin-Induced Acute Kidney Injury in Rats by Decreasing Inflammatory Cytokines and Reactive Oxygen Species.

Septic shock can increase pro-inflammatory cytokines, reactive oxygen species (ROS), and multiple organ dysfunction syndrome (MODs) and even lead to death. Dipeptidyl peptidase-4 (DPP-4) inhibitors have been proven to exert potential antioxidant and anti-inflammatory effects. We investigated the effects of linagliptin on endotoxic shock and acute kidney injury (AKI) in animal and cell models. In the cell model, linagliptin attenuated ROS by activating the AMP-activated protein kinase (AMPK) pathway, restoring nuclear-factor-erythroid-2-related factor (Nrf2) and heme oxygenase 1 (HO-1) protein, and decreasing pro-inflammatory cytokines (tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1ß)). In the animal model, 14-week-old conscious Wistar-Kyoto rats were randomly divided into three groups (n = 8 in each group). Endotoxin shock with MODs was induced by the intravenous injection of Klebsiella pneumoniae lipopolysaccharide (LPS, 20 mg/kg). Linagliptin improved animal survival without affecting hemodynamic profiles. In the histopathology and immunohistochemistry examinations of the rat kidneys, linagliptin (10 mg/kg) suppressed nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and inducible nitric oxide synthase (iNOS), decreased injury scores, and preserved E-cadherin expression from LPS damage. In conclusion, linagliptin ameliorated endotoxin-shock-induced AKI by reducing ROS via AMPK pathway activation and suppressing the release of TNF-α and IL-1ß in conscious rats.

Suppression of multiple processes relevant to cancer progression by benzyl isothiocyanate may result from the inhibition of Aurora A kinase activity.

Cruciferous vegetables are good sources of phytochemicals that have the potential to prevent cancer. Benzyl isothiocyanate (BITC) is the hydrolysis product of glucosinolates that are especially abundant in cruciferous vegetables. The anti-cancer activities of BITC have been studied for decades. The mechanisms of reducing the incidence of cancer by BITC involve multiple pathways, including the inhibition of proliferation, induction of apoptosis and inhibition of angiogenesis. One of the major common phenotypes induced by BITC in previous studies is G2/M cell cycle arrest. Therefore, interference of mitosis progression is likely to be an important anti-tumor mechanism of BITC. Using immunofluorescence staining, we show that BITC induces cell arrest in mitosis by perturbation of mitotic spindles. The abnormal mitotic spindles were resulted from the inactivation of Aurora A by BITC. The fact that BITC inhibits the activation of Aurora A and disrupts mitotic spindles provides one of the possible explanations why BITC is able to arrest cells in the G2/M phase and induce apoptosis in many previous studies. Besides, Aurora A is an essential player of mitosis and also has non-mitotic functions in tumorigenesis. As an inhibitor of Aurora A, BITC not only is an antimitotic agent but also inhibits tumor progression via many pathways.

Vanadocene dichloride inhibits cell proliferation by targeting Aurora B.

Vanadocene dichloride (VDC) was shown to exhibit antitumor properties against a wide spectrum of tumor cell lines. Many studies have been carried out to reveal the bioactivities of VDC and the interaction mechanism of VDC with biological molecules in test tubes. One of the bioactivities of VDC is to arrest the cell cycle at the G2/M phase. However, its underlying mechanisms of action and cytotoxicity profile are still not fully understood. HeLa cells were used in this study, and the IC50 value of VDC was 8.61 µM after a 24-hour treatment. We used an immunofluorescence staining method to analyze the morphology of cells in the mitosis stage to elucidate what defects caused cell arrest in mitosis. Chromosomal misalignment was found to be the major phenotype. One of the proteins responsible for chromosome alignment at the metaphase is Aurora B kinase. Results of immunoblotting assay showed that Aurora B kinase activity was inhibited by VDC treatment. More than 50% of the Aurora B activity was inhibited when cells were treated with VDC at a concentration of 6.25 µM. That VDC was able to induce defects in chromosomal alignment at the metaphase by inhibiting the activity of Aurora B kinase is an important mechanism of VDC to be developed as an antitumor agent.

Anticancer activity of Kalanchoe tubiflora extract against human lung cancer cells in vitro and in vivo.

Uncontrolled cell proliferation is a common feature of human cancer. Some of herbal extract or plant-derived medicine had been shown as an important source of effective anticancer agents. We previously reported that an n-BuOH-soluble fraction of Kalanchoe tubiflora has antiproliferative activity by inducing mitotic catastrophe. In this study, we showed that the H2 O-soluble fraction of Kalanchoe tubiflora (KT-W) caused cell cycle arrest, and senescence-inducing activities in A549 cells. We used 2 dimensional PAGE to analyze the protein expression levels after KT-W treatment, and identified that the energy metabolism-related proteins and senescence-related proteins were disturbed. In vivo experiments showed that the tumor growths in A549-xenografted nude mice were effectively inhibited by KT-W. Our findings implied that KT-W is a putative antitumor agent by inducing cell cycle arrest and senescence. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1663-1673, 2016.

Euphorbia formosana root extract induces apoptosis by caspase-dependent cell death via Fas and mitochondrial pathway in THP-1 human leukemic cells.

Acute myeloid leukemia (AML), a very rare type of cancer, generally affects patients over 50 years old. While clinical drugs to treat advanced stages of AML exist, the disease becomes increasingly resistant to therapies. Euphorbia formosana Hayata (EF) is a native Taiwanese medicinal plant used to treat rheumatism, liver cirrhosis, herpes zoster, scabies, and photoaging, along with tumor suppression. However, the mechanisms by which it suppresses tumors have not been explored. Here, we provide molecular evidence that a hot-water extract of Euphorbia formosana (EFW) selectively inhibited the growth of human leukemic cancer cells more than other solid human cancer cell lines. Most importantly, the plant extract had limited toxicity toward healthy peripheral blood mononuclear cells (PBMCs). After THP-1 leukemic cells were treated with 50-100 µg/mL EFW for one day, the S phase DNA content of the cells increased, while treatment with 200-400 µg/mL caused the cells to accumulate in the G0/G1 phase. Notably, EFW did not affect A-549 lung cancer cells. The effectiveness of EFW against THP-1 cells may be through caspase-dependent apoptosis in leukemic cells, which is mediated through the Fas and mitochondrial pathways. The potent antileukemic activity of EFW in vitro warrants further investigation of this plant to treat leukemias and other malignancies.

Kalanchoe tubiflora extract inhibits cell proliferation by affecting the mitotic apparatus.

BACKGROUND: Kalanchoe tubiflora (KT) is a succulent plant native to Madagascar, and is commonly used as a medicinal agent in Southern Brazil. The underlying mechanisms of tumor suppression are largely unexplored. METHODS: Cell viability and wound-healing were analyzed by MTT assay and scratch assay respectively. Cell cycle profiles were analyzed by FACS. Mitotic defects were analyzed by indirect immunofluoresence images. RESULTS: An n-Butanol-soluble fraction of KT (KT-NB) was able to inhibit cell proliferation. After a 48 h treatment with 6.75 µg/ml of KT, the cell viability was less than 50% of controls, and was further reduced to less than 10% at higher concentrations. KT-NB also induced an accumulation of cells in the G2/M phase of the cell cycle as well as an increased level of cells in the subG1 phase. Instead of disrupting the microtubule network of interphase cells, KT-NB reduced cell viability by inducing multipolar spindles and defects in chromosome alignment. KT-NB inhibits cell proliferation and reduces cell viability by two mechanisms that are exclusively involved with cell division: first by inducing multipolarity; second by disrupting chromosome alignment during metaphase. CONCLUSION: KT-NB reduced cell viability by exclusively affecting formation of the proper structure of the mitotic apparatus. This is the main idea of the new generation of anti-mitotic agents. All together, KT-NB has sufficient potential to warrant further investigation as a potential new anticancer agent candidate.

Preferential promotion of apoptosis of monocytes by Lactobacillus casei rhamnosus soluble factors.

BACKGROUND & AIMS: Inflammatory bowel disease (IBD) is characterized by dense infiltrates of and defective apoptosis by mucosal cell populations. Some probiotics inhibit monocytes' expansion, although mechanisms remain unknown. Supernatants of Lactobacillus strains were investigated for inducing apoptosis of monocytes. METHODS: Secreted factors produced by Lactobacillus strains were tested on human lymphocytes, monocytes and a human monocytic leukemia-cell line (THP-1). Cell death mechanisms were investigated by a variety of methods. Lipopolysaccharide (LPS)-induced proinflammatory cytokines (IL-1beta, IL-6, IL-8, TNF-alpha) and anti-inflammatory TGF-beta1 were determined. RESULTS: Soluble factor(s) from Lactobacillus casei rhamnosus strain supernatants (LcrS) effectively induced apoptosis of immune cells. These were mainly soluble proteins (MW 5-30 kDa; LcrS(5-30)). For immune cells, but not human colonic epithelial carcinoma cells (HT-29), pretreatment with LcrS(5-30) significantly promoted apoptosis via a mitochondrial pathway. LcrS(5-30) suppressed pro-inflammatory cytokines and induced anti-inflammatory TGF-beta1. CONCLUSIONS: Probiotic Lcr produced heat-stable molecules (MW range 5-30 kDa) that promoted immune cell apoptosis without affecting intestinal epithelial cells. LcrS(5-30) triggered apoptosis by a mitochondrial pathway, but not via TGF-beta signaling pathway. LcrS(5-30) also inhibited LPS-induced inflammatory cytokines by immune cells. Thus, LcrS(5-30) promotes apoptosis of immune cells, and suggests probiotics-based regimens for prevention of IBD.