16 research outputs found

    Freeze-Drying of Mononuclear Cells Derived from Umbilical Cord Blood Followed by Colony Formation

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    BACKGROUND: We recently showed that freeze-dried cells stored for 3 years at room temperature can direct embryonic development following cloning. However, viability, as evaluated by membrane integrity of the cells after freeze-drying, was very low; and it was mainly the DNA integrity that was preserved. In the present study, we improved the cells' viability and functionality after freeze-drying. METHODOLOGY/PRINCIPAL FINDINGS: We optimized the conditions of directional freezing, i.e. interface velocity and cell concentration, and we added the antioxidant EGCG to the freezing solution. The study was performed on mononuclear cells (MNCs) derived from human umbilical cord blood. After freeze-drying, we tested the viability, number of CD34(+)-presenting cells and ability of the rehydrated hematopoietic stem cells to differentiate into different blood cells in culture. The viability of the MNCs after freeze-drying and rehydration with pure water was 88%-91%. The total number of CD34(+)-presenting cells and the number of colonies did not change significantly when evaluated before freezing, after freeze-thawing, and after freeze-drying (5.4 x 10(4)+/-4.7, 3.49 x 10(4)+/-6 and 6.31 x 10(4)+/-12.27 cells, respectively, and 31+/-25.15, 47+/-45.8 and 23.44+/-13.3 colonies, respectively). CONCLUSIONS: This is the first report of nucleated cells which have been dried and then rehydrated with double-distilled water remaining viable, and of hematopoietic stem cells retaining their ability to differentiate into different blood cells

    Chelators in Iron and Copper Toxicity

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    Purpose of Review Chelation therapy is used for diseases causing an imbalance of iron levels (for example haemochromatosis and thalassaemia) or copper levels (for example Menkes’ and Wilson’s diseases). Currently, most pharmaceutical chelators are relatively simple but often have side effects. Some have been taken off the market. This review attempts to find theory and knowledge required to design or find better chelators. Recent Findings Recent research attempting to understand the biological mechanisms of protection against iron and copper toxicity is reviewed. Understanding of molecular mechanisms behind normal iron/copper regulation may lead to the design of more sophisticated chelators. The theory of metal ion toxicity explains why some chelators, such as EDTA, which chelate metal ions in a way which exposes the ion to the surrounding environment are shown to be unsuitable except as a means of killing cancer cells. The Lewis theory of acids and bases suggests which amino acids favour the attachment of the hard/intermediate ions Fe2+, Fe3+, Cu2+ and soft ion Cu+. Non-polar amino acids will chelate the ion in a position not in contact with the surrounding cellular environment. The conclusion is that only the soft ion binding cysteine and methionine appear as suitable chelators. Clearly, nature has developed proteins which are less restricted. Recent research on naturally produced chelators such as siderophores and phytochemicals show some promise as pharmaceuticals. Summary Although an understanding of natural mechanisms of Fe/Cu regulation continues to increase, the pharmaceutical chelators for metal overload diseases remain simple non-protein molecules. Natural and synthetic alternatives have been studied but require further research before being accepted

    Evaluation of Anti-Hyperglycemia and Complications of Red and Black Thai Jasmine Rice Cultivars in Streptozotocin-Induced Diabetic Rats

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    The phytochemical constituents of red (RR) and black (BR) rice extracts were determined using high-pressure liquid chromatography (HPLC). Phytochemical screening revealed the presence of catechin, rutin, isoquercetin, cyanidin 3-glucoside, cyanidin 3-O-rutinoside, peonidin and quercetin. The anti-diabetic activities of RR and BR extracts on diabetic complications were examined in a streptozotocin-induced diabetic rat model. Rats (n = 80) were divided into 10 groups (n = 8 rats per group). Healthy and diabetic RR or BR-treated groups received 10, 50, or 200 mg of RR or BR per kg of body weight daily for 45 days. The results demonstrated significantly improved glucose control in rats administered RR or BR, while triglyceride and cholesterol levels were reduced in the diabetic groups. Moreover, RR or BR treatment led to decreased levels of malondialdehyde, aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, and creatinine. Further, glutathione concentration was significantly increased in both serum and liver tissue from RR- and BR-treated diabetic rats

    Anti-cancer effect of a phytochemical compound – 7R-acetylmelodorinol – against triple-negative breast cancer cells

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    Triple-negative breast cancer (TNBC) is a highly aggressive subtype currently lacking effective treatment options. Consequently, novel and effective drugs or compounds are urgently needed to treat TNBC. Therefore, this study aimed to evaluate the potential of 7R-acetylmelodorinol (7R-AMDL), a phytochemical compound isolated from Xylopia pierrei Hance, a plant found in Thailand, as a novel therapeutic agent for TNBC. MTT and clonogenic assays showed that 7R-AMDL significantly reduced the survival of breast cancer cell lines, with a markedly potent effect on MDA-MB-231 cells. Flow cytometry showed that treating MDA-MB-231 cells with 7R-AMDL at the concentration of dose 8 µM significantly increased early and late apoptosis after 24 and 48 h compared to the control group (p < 0.0001). The highest tested 7R-AMDL dose upregulated the death receptors and their ligands, with extrinsic and intrinsic apoptosis pathways significantly activated via the caspase cascade, compared to the untreated group (p < 0.05). In addition, immunoblots showed decreased BCL2-like 1 (BCL2L1/Bcl-xL) expression (p < 0.0001). Furthermore, wound healing and Transwell assays showed that at a non-cytotoxic dose (≤4 µM), 7R-AMDL significantly inhibited the MDA-MB-231 cell migration and invasion. This reduction in cell migration was associated with decreased matrix metallopeptidase 9 (MMP-9) expression (p < 0.01) and nuclear factor kappa B (NF-κB) activation (p < 0.05). Altogether, 7R-AMDL has anti-cancer effects against TNBC and the potential to be further developed and evaluated for treating this disease

    Green tea polyphenols require the mitochondrial iron transporter, mitoferrin

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    Green tea has been found to increase the lifespan of various experimental animal models including the fruit fly, Drosophila melanogaster. High in polyphenolic content, green tea has been shown to reduce oxidative stress in part by its ability to bind free iron, a micronutrient that is both essential for and toxic to all living organisms. Due to green tea’s iron-binding properties, we questioned whether green tea acts to increase the lifespan of the fruit fly by modulating iron regulators, specifically, mitoferrin, a mitochondrial iron transporter, and transferrin, found in the hemolymph of flies. Publicly available hypomorph mutants for these iron-regulators were utilized to investigate the effect of green tea on lifespan and fertility. We identified that green tea could not increase the lifespan of mitoferrin mutants but did rescue the reduced male fertility phenotype. The effect of green tea on transferrin mutant lifespan and fertility were comparable to w(1118) flies, as observed in our previous studies, in which green tea increased male fly lifespan and reduced male fertility. Expression levels in both w(1118) flies and mutant flies, supplemented with green tea, showed an up-regulation of mitoferrin but not transferrin. Total body and mitochondrial iron levels were significantly reduced by green tea supplementation in w(1118) and mitoferrin mutants but not transferrin mutant flies. Our results demonstrate that green tea may act to increase the lifespan of Drosophila in part by the regulation of mitoferrin and reduction of mitochondrial iron
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