Arsenic abrogates the estrogen-signaling pathway in the rat uterus

<p>Abstract</p> <p>Background</p> <p>Arsenic, a major pollutant of water as well as soil, is a known endocrine disruptor, and shows adverse effects on the female reproductive physiology. However, the exact molecular events leading to reproductive dysfunctions as a result of arsenic exposure are yet to be ascertained. This report evaluates the effect and mode of action of chronic oral arsenic exposure on the uterine physiology of mature female albino rats.</p> <p>Methods</p> <p>The effect of chronic oral exposure to arsenic at the dose of 4 microg/ml for 28 days was evaluated on adult female albino rats. Hematoxylin-eosin double staining method evaluated the changes in the histological architecture of the uterus. Circulating levels of gonadotropins and estradiol were assayed by enzyme-linked immunosorbent assay. Expression of the estrogen receptor and estrogen-induced genes was studied at the mRNA level by RT-PCR and at the protein level by immunohistochemistry and western blot analysis.</p> <p>Results</p> <p>Sodium arsenite treatment decreased circulating levels of estradiol in a dose and time-dependent manner, along with decrease in the levels of both LH and FSH. Histological evaluation revealed degeneration of luminal epithelial cells and endometrial glands in response to arsenic treatment, along with reduction in thickness of the longitudinal muscle layer. Concomitantly, downregulation of estrogen receptor (ER alpha), the estrogen-responsive gene - vascular endothelial growth factor (VEGF), and G1 cell cycle proteins, cyclin D1 and CDK4, was also observed.</p> <p>Conclusion</p> <p>Together, the results indicate that arsenic disrupted the circulating levels of gonadotropins and estradiol, led to degeneration of luminal epithelial, stromal and myometrial cells of the rat uterus and downregulated the downstream components of the estrogen signaling pathway. Since development and functional maintenance of the uterus is under the influence of estradiol, arsenic-induced structural degeneration may be attributed to the reduction in circulating estradiol levels. Downregulation of the estrogen receptor and estrogen-responsive genes in response to arsenic indicates a mechanism of suppression of female reproductive functions by an environmental toxicant that is contra-mechanistic to that of estrogen.</p

ENHANCED p53-DEPENDENT GROWTH INHIBITION OF HUMAN GLIOBLASTOMA CELLS BY COMBINATORIAL TREATMENT OF TEMOZOLOMIDE AND NOVEL PURIFIED NATURAL CARBOHYDRATE OF PLEUROTUS FLORIDA

Objective: This study was designed to analyze the combinatorial chemotherapeutic effect of temozolomide (TMZ), the most common drug in glioblastoma treatment and a purified carbohydrate (Fr-II) from the edible mushroom Pleurotus florida, on human glioblastoma cell lines.Methods: Fr-II was purified by size-exclusion chromatography and characterised by different mass spectroscopy analysis. Human glioblastoma cells were treated with TMZ, Fr-II, and combination of TMZ and Fr-II. Cell cytotoxicity was measured by MTT assay, cell cycle phase distribution was determined by cell cycle analysis and followed by the relative p53 protein expression was analyzed by western blot analysis.Results: Chemical analysis of Fr-II confirmed the glycosidically linked two units of glucose with terminally attached mannitol with mass of 506 Da. Fr-II treatment exhibited cytotoxicity in both the cell lines in a dose-dependent manner with most effective dose at 200µg/ml. When Fr-II (200µg/ml) was combined with a dose range of TMZ it showed a more cellular cytotoxicity compared to the cytotoxicity of TMZ alone with most oppressive combinatorial dose at 400µM (TMZ)+200µg/ml (Fr-II). In compliance, with the above results, both cell lines showed a 10% increase in no. of cells (p&lt;0.05) in G2/M phase indicating an arrest of cell cycle and increased p53 protein expression (p&lt;0.05) at the combinatorial dose than TMZ alone at 400µM, but Fr-II alone didn't show any cell cycle arrest nor did it show increased p53 expression.Conclusion: Therefore it confirms that Fr-II synergizes with TMZ to significantly intensify its anti-proliferative properties, thereby emerging as an effective element for combinatorial treatment of glioblastoma

A Protective Role of Arecoline Hydrobromide in Experimentally Induced Male Diabetic Rats

Objectives. Arecoline, the most potent and abundant alkaloid of betel nut, causes elevation of serum testosterone and androgen receptor expression in rat prostate, in addition to increase in serum insulin levels in rats, leading to insulin resistance and type 2 diabetes-like conditions. This study investigated the role of arecoline on the reproductive status of experimentally induced type 1 diabetic rats. Methods. Changes in the cellular architecture were analyzed by transmission electron microscopy. Blood glucose, serum insulin, testosterone, FSH, and LH were assayed. Fructose content of the coagulating gland and sialic acid content of the seminal vesicles were also analyzed. Results. Arecoline treatment for 10 days at a dose of 10 mg/kg of body weight markedly facilitated β-cell regeneration and reversed testicular and sex accessory dysfunctions by increasing the levels of serum insulin and gonadotropins in type 1 diabetic rats. Critical genes related to β-cell regeneration, such as pancreatic and duodenal homeobox 1 (pdx-1) and glucose transporter 2 (GLUT-2), were found to be activated by arecoline at the protein level. Conclusion. It can thus be suggested that arecoline is effective in ameliorating the detrimental effects caused by insulin deficiency on gonadal and male sex accessories in rats with type 1 diabetes

Side-Chain Amino-Acid-Based pH-Responsive Self-Assembled Block Copolymers for Drug Delivery and Gene Transfer

Developing safe and effective nanocarriers for multitype of delivery system is advantageous for several kinds of successful biomedicinal therapy with the same carrier. In the present study, we have designed amino acid biomolecules derived hybrid block copolymers which can act as a promising vehicle for both drug delivery and gene transfer. Two representative natural chiral amino acid-containing (l-phenylalanine and l-alanine) vinyl monomers were polymerized via reversible addition–fragmentation chain transfer (RAFT) process in the presence of monomethoxy poly­(ethylene glycol) based macro-chain transfer agents (mPEG_<i>n</i>-CTA) for the synthesis of well-defined side-chain amino-acid-based amphiphilic block copolymers, monomethoxy poly­(ethylene glycol)-<i>b</i>-poly­(Boc-amino acid methacryloyloxyethyl ester) (mPEG_<i>n</i>-<i>b</i>-P­(Boc-AA-EMA)). The self-assembled micellar aggregation of these amphiphilic block copolymers were studied by fluorescence spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM). Potential applications of these hybrid polymers as drug carrier have been demonstrated <i>in vitro</i> by encapsulation of nile red dye or doxorubicin drug into the core of the micellar nanoaggregates. Deprotection of side-chain Boc- groups in the amphiphilic block copolymers subsequently transformed them into double hydrophilic pH-responsive cationic block copolymers having primary amino groups in the side-chain terminal. The DNA binding ability of these cationic block copolymers were further investigated by using agarose gel retardation assay and AFM. The <i>in vitro</i> cytotoxicity assay demonstrated their biocompatible nature and these polymers can serve as “smart” materials for promising bioapplications

Lactoferrin-tethered betulinic acid nanoparticles promote rapid delivery and cell death in triple negative breast and laryngeal cancer cells

Cancer management presents multifarious problems. Triple negative breast cancer (TNBC) is associated with inaccurate prognosis and limited chemotherapeutic options. Betulinic acid (BA) prevents angiogenesis and causes apoptosis of TNBC cells. NIH recommends BA for rapid access in cancer chemotherapy because of its cell-specific toxicity. BA however faces major challenges in therapeutic practices due to its limited solubility and cellular entree. We report lactoferrin (Lf) attached BA nanoparticles (Lf-BAnp) for rapid delivery in triple negative breast (MDA-MB-231) and laryngeal (HEp-2) cancer cell types. Lf association was confirmed by SDS-PAGE and FT-IR analysis. Average hydrodynamic size of Lf-BAnp was 147.7 ± 6.20 nm with f potential of �28.51 ± 3.52 mV. BA entrapment efficiency was 75.38 ± 2.70% and the release mechanism followed non-fickian pattern. Impact of Lf-BAnp on cell cycle and cytotoxicity of triple negative breast cancer and its metastatic site laryngeal cancer cell lines were analyzed. Lf-BAnp demonstrated strong anti-proliferative and cytotoxic effects, along with increased sub-G1 population and reduced number of cells in G1 and G2/M phases of the cell cycle, confirming reduced cell proliferation and significant cell death. Speedy intracellular entry of Lf-BAnp occurred within 30 min. Lf-BAnp design was explored for the first time as safer chemotherapeutic arsenals against complex TNBC conditions