Inhibitory Effect of Polypodium Leucotomos Extract on Cytochrome P450 3A-mediated Midazolam Metabolism

Polypodium leucotomos（PL）is a fern native to Latin America, and its extract is used as an oral sunscreen; however, its safety during use has not been adequately investigated. Therefore, the aim of this study was to evaluate food-drug interactions associated with PL extract mediated by cytochrome P450 3A（CYP3A）inhibition and induction. Inhibition of CYP3A-mediated midazolam（MDZ）1’-hydroxylation activity by PL extract and its major phenolic components was evaluated in vitro using pooled human liver microsomes. In addition, MDZ pharmacokinetics were investigated in rats after a single dose, as well as after 1 week treatment with PL extract（30mg/kg）in order to evaluate the inhibitory and inducible effects of PL on CYP3A in vivo, respectively. Serum MDZ concentrations were analyzed and pharmacokinetic parameters were compared between PL- and water（control）-treated groups. In vitro, PL extract decreased MDZ 1’-hydroxylation activity in a concentration-dependent manner. However, the major phenolic compounds in PL extracts, namely caffeic, chlorogenic, p-coumaric, ferulic, and vanillic acids, did not exhibit any marked inhibitory effects on MDZ 1’-hydroxylation activity. In vivo, administration of a single dose of PL extract to rats significantly increased the area under the serum concentration-time curve from time 0 to infinity（AUC0–∞）and the maximum serum concentration（Cmax）of MDZ（by 57％ and 88％, respectively; P＜0.05）. In contrast, there were no significant changes in MDZ pharmacokinetic parameters after 1 week of treatment with PL extract. These results suggest that PL extract can cause a food-drug interaction by inhibiting CYP3A

Comparison of Anti-Inflammatory Analgesics for Mechanical Stress-induced Inflammation in a Human Synovial Sarcoma Cell Line

Osteoarthritis is a complicated clinical condition affected by age, mechanical stress, cartilage hypertrophy, cytokines, and genetic predisposition. In this study, we compared the effects of various anti-inflammatory analgesics on mechanical stress-induced inflammation in a synovial sarcoma cell line （SW982 cells）. SW982 cells exposed to mechanical stress by shaking with hydroxyapatite-simulating bone chips were treated with acetaminophen, ketoprofen, triamcinolone acetonide, celecoxib, or neurotrophin for 48hr. The expression of integrin α5β1 receptor, observed in fibroblasts and synovium, was evaluated. Levels of the transcription factor, nuclear factor-κB, the inflammatory cytokine, tumor necrosis factor-α, the proteolytic enzyme, matrix metalloproteinase-3, and prostaglandin E2, which is associated with pain and arachidonate cascade product levels, were measured by ELISA. The expression of integrin α5β1 was significantly increased by mechanical stress. Activation of nuclear factor-κB by mechanical stress was significantly suppressed by celecoxib only. Mechanical stress-induced increases in tumor necrosis factor-α and matrix metalloproteinase-3 levels were significantly suppressed by acetaminophen, triamcinolone acetonide, and neurotrophin. The mechanical stress-induced increase in prostaglandin E2 levels was significantly suppressed by acetaminophen, ketoprofen, and celecoxib. SW982 exposed to mechanical stress is proposed as a model for arthritis, and indeed, the expression of integrin α5β1, a membrane receptor protein that binds to fibronectin and the extracellular matrix, and is involved in cell proliferation, differentiation, and neovascularization in osteoarthritis, was significantly upregulated. Following evaluation using this model, acetaminophen was found to possess anti-inflammatory, analgesic, and joint-destruction suppression properties. This drug may, therefore, have applications in the treatment of mechanical stress-induced inflammation

The Synergistic Antitumor Effect of Combined Anti-Human Epidermal Growth Factor Receptor 2 Antibody and Gamma Interferon Therapy on Antibody-resistant Breast Cancer Cells

The anti-human epidermal growth factor receptor 2 （HER2） antibody （Ab） is a molecularly targeted Ab for cancer therapy. In the field of breast cancer, approximately 20％ overexpress HER2 protein. However, the recurrence rate is 30％ and the metastasis rate is 18％ one year after treatment of anti-HER2 Ab for HER2 positive breast cancer. The resistance to Ab treatment is a major problem for patients. We previously reported that anti-HER2 Ab and Gamma Interferon （IFN-γ） combined therapy show a higher anti-tumor effect than typical therapy in in vitro and in vivo mouse experiments. In this study, we evaluated whether anti-HER2 Ab and IFN-γ combined therapy shows a good synergistic effect against drug-resistant HER2 positive breast cancer cells and a higher antitumor effect than chemotherapy as a conventional clinical treatment. Further, we evaluated a synergy effect with the PD-L1 as a new check point inhibitor. The resistant cell lines were made under the continuous presence of Ab until cell growth was not affected by the drug. The resistant cells were divided into the appropriate number of groups, and then treated with anti-cancer therapy. We evaluated the antitumor effect for both the in vitro study and in vivo mouse xenograft model prepared with the same immunogenicity. The differences of immunofluorescence staining of CD8, Gr-1 and PDL-1 in tissues were investigated, especially in relation to the immune system. The combined therapy showed a significantly higher anti-tumor effect than other groups in in vitro and in vivo experiments. The combined therapy affected anti-tumor immunity in this immunofluorescence experiment. Taken together, we showed the possibility that combined therapy could be an effective treatment option for anti-HER2 Ab resistant breast cancer, thus helping patients suffering from cancer progression after developing treatment resistance

Correlations between Oxidative Stress and Blood Lipids Are Stronger in Men than Women

Oxidative stress is one cause of atherosclerosis that makes it a lifestyle-related disease. Oxidized low-density lipoprotein （OxLDL） was previously found to be related to oxidative stress, measured using the diacron-reactive oxygen metabolites （d-ROMs） test and showed a negative correlation between biological antioxidant potential （BAP） test results and triglycerides （TG）. In addition, large gender differences exist among vascular disorders caused by arteriosclerosis. However, such gender differences and their correlation with oxidative stress and blood lipids have not been clarified. In this study, gender differences in correlations between oxidative stress and blood lipids as factors in the development of atherosclerosis was addressed. Subjects were 149 individuals who underwent medical examinations conducted in Ashikaga Teishin Clinic in Tochigi, Japan （98 males and 51 females）. A strong positive correlation was observed between d-ROMs test results and OxLDL in men （R＝0.480, P<0.0001）, but no correlation was seen in women. A strong negative correlation between BAP test results and TG was also noted in men （R＝−0.571, P<0.0001）, and a moderate negative correlation was detected in women （R＝−0.344, P＝0.0133）. A positive correlation between d-ROMs tests and OxLDL was seen in women under 50 years of age （R＝0.399, P＝0.0393）, but this correlation was not present in women who were 50 years of age or older （R＝−0.00656, P＝0.976）. Correlations between oxidative stress and OxLDL and between antioxidant potential and TG in men were more prominent than in women. This finding suggests that decreasing oxidative stress in the blood to prevent atherosclerosis is more important for men

High molecular weight amyloid β1-42 oligomers induce neurotoxicity via plasma membrane damage.

Amyloid β-protein (Aβ) molecules tend to aggregate and subsequently form low MW (LMW) oligomers, high MW (HMW) aggregates such as protofibrils, and ultimately fibrils. These Aβ species can generally form amyloid plaques implicated in the neurodegeneration of Alzheimer disease (AD), but therapies designed to reduce plaque load have not demonstrated clinical efficacy. Recent evidence implicates amyloid oligomers in AD neuropathology, but the precise mechanisms are uncertain. We examined the mechanisms of neuronal dysfunction from HMW-Aβ1-42 exposure by measuring membrane integrity, reactive oxygen species (ROS) generation, membrane lipid peroxidation, membrane fluidity, intracellular calcium regulation, passive membrane electrophysiological properties, and long-term potentiation (LTP). HMW-Aβ1-42 disturbed membrane integrity by inducing ROS generation and lipid peroxidation, resulting in decreased membrane fluidity, intracellular calcium dysregulation, depolarization, and impaired LTP. The damaging effects of HMW-Aβ1-42 were significantly greater than those of LMW-Aβ1-42. Therapeutic reduction of HMW-Aβ1-42 may prevent AD progression by ameliorating direct neuronal membrane damage.-Yasumoto, T., Takamura, Y., Tsuji, M., Watanabe-Nakayama, T., Imamura, K., Inoue, H., Nakamura, S., Inoue, T., Kimura, A., Yano, S., Nishijo, H., Kiuchi, Y., Teplow, D. B., Ono, K. High molecular weight amyloid β1-42 oligomers induce neurotoxicity via plasma membrane damage

Construction of an All-in-one Double-conditional shRNA Expression Vector

Gene silencing by RNA interference （RNAi） is widely used for assessing gene function. An important advance in the RNAi field was the discovery that plasmid-based RNAi can substitute for synthetic small interfering RNA in vitro and in vivo. However, constitutive and ubiquitous knockdown of gene expression by RNAi in mice can limit the scope of experiments because this process can lead to embryonic lethality, or result in compensatory overexpression of other genes such that no phenotypic abnormalities occur. Either way, analyses of the physiological roles of the gene of interest in adult mice are not possible. To overcome these limitations, we previously constructed a double-conditional short-hairpin RNA （shRNA） expression vector that can regulate shRNA expression in a spatio-temporal manner with a tetracycline-inducible floxed stuffer sequence selectively excised by application of Cre recombinase. In this study, we aimed to modify this vector to create an all-in-one vector that produces double-conditional transgenic mice through a single round of gene transfer to fertilized eggs. We added a coding region for nuclear localizing Cre （NCre） recombinase with a multi-cloning site for a cell-specific promoter into the double-conditional short-hairpin RNA （shRNA） expression vector that we previously constructed. Using Escherichia coli, we confirmed successful construction of the vector. First, we confirmed isopropyl-β-D-thiogalactopyranoside-induced expression of NCre recombinase through the lac operon as a specific promoter by western blotting. Second, we confirmed functional recombination of the floxed sequence of loxP-like TATA-lox by analysing restriction enzyme-digested fragments. This all-in-one double-conditional shRNA expression vector will be useful for reversible in vitro and in vivo knockdown of target gene expression, in target cells via promoter-specific expression of NCre, and at specific times by tetracycline application

Eribulin Treatment Induces High Expression of miR-195 and Inactivates the Wnt/β - catenin Signaling Pathway in Triple-negative Breast Cancer

Triple-negative breast cancer （TNBC） accounts for 10-15％ of all breast cancer cases and shows a poor prognosis with 30％ distant metastasis. With few specific target molecules and ineffective hormonal and anti-HER2 treatment, an alternative therapeutic method for TNBC is urgently required. Recently, a non-taxane inhibitor of microtubule dynamics called eribulin was developed for breast cancer therapy. Eribulin induces irreversible mitotic mass formation in cancer cells during the G2-M phase, initiating apoptosis; however, the mechanism underlying this eribulin activity remains unclear. We reported previously that exposing non-basal-like （NBL） TNBC cells to eribulin increases miR-195 expression, which in turn decreases the expression of targeted Wnt3a. The present study sought to further clarify the mechanism of this antitumor effect by exploring how eribulin affects Wnt/β - catenin signaling based on miRNA expression changes in TNBC. In an NBL type of human breast cancer cell line （MDA-MB-231 cells）, we compared the expression levels of Wnt/β catenin signaling pathway proteins in cells exposed to an miR-195 mimic （cells transfected with miR-195 and in which Wnt3a expression was suppressed） and in cells exposed to eribulin. Expression levels of Wnt3a, β -catenin, and GSK-3β were measured by ELISA and observed by fluorescence immunostaining. Wnt3a and β -catenin expression was significantly lower and GSK-3β expression was significantly higher in the cells exposed to eribulin and transfected with miR-195 mimic than in the untreated controls, suggesting that eribulin inactivates the Wnt/β -catenin signaling pathway. Therefore, a novel antitumor mechanism of eribulin was determined, whereby eribulin induces high expression of miR-195 to inactivate the Wnt/β -catenin signaling pathway in NBL-type TNBC

Effects of ferric citrate on intracellular oxidative stress markers after hydrogen peroxide treatment of human U937 monocytes

Phosphate binders, such as iron （III） citrate hydrate （FCH）, are essential medications for hemodialysis patients. Some in vivo studies have demonstrated that FCH prevented induction of oxidative stress in the presence of transferrin. However, how FCH affects iron-related oxidative stress in the absence of transferrin remains unclear. In the current study, we investigated the effects of ferric citrate （FC） on oxidative stress in the absence of transferrin in vitro to address this question. Human U937 monocytes were pretreated with FC, iron （II） chloride tetrahydrate （FeCl2・4H2O）, iron （III） chloride hexahydrate （FeCl3・6H2O）, or saccharated ferric oxide for 24 h and then treated with 10-mM hydrogen peroxide （H2O2） for 30 min. The final Fe concentrations were adjusted to approximately 200µg/dl. Iron concentration, intracellular reactive oxygen species （ROS） levels, and intracellular lipid peroxidation of the cell membrane were measured. After treatment with FC, iron concentration and ROS levels increased. Change in lipid peroxidation after treatment with FC was not observed. However, after treatment with H2O2, no change was observed in the intracellular ROS levels in FC-pretreated cells, whereas lipid peroxidation of the cell membrane was decreased. Despite the high iron concentration in FC-pretreated cells, neither intracellular ROS nor cell membrane lipid peroxidation levels were increased with H2O2 treatment. Their results might represent antioxidative effects of FC. The results of this study may contribute to a better understanding of the effects of oxidative stress in hemodialysis patients treated with FCH