Role of Synthesized Organoselenium Compounds on Protection of Rat Erythrocytes from DMBA-Induced Oxidative Stress

Formation of free radicals is not limited to normal cellular process but also occur upon exposure to certain chemicals (polycyclic aromatic hydrocarbon, cadmium, lead, etc.), cigarette smoke, radiation, and high-fat diet. Free-radical damage is an important factor in many pathological and toxicological processes. Selenium, an essential micronutrient, is a associated with antioxidant functions, physiological defense mechanisms against different diseases including several types of cancers. Search for new selenium compounds with more chemopreventive activities and less toxicities are in progress. In addition, there has been a growing interest in the synthesis of organoselenium compounds with respect to their use in enzymology and bioorganic chemistry. In the present study, adult female Wistar rats were treated with 7,12-dimethylbenz[a]anthracene (DMBA) and the organoselenium compounds [1-isopropyl-3-methylbenzimidazole-2-selenone (Se I) and 1, 3-di-p-methoxybenzylpyrimidine-2-selenone (Se II)] in determined doses. The protective effects of synthetic organoselenium compounds (Se I and Se II) against DMBA-induced changes in antioxidant enzyme (superoxide dismutase, glutathione peroxidase (GSH-Px), catalase (CAT), glutathione reductase (GR)) activities, total GSH, and malondialdehyde (MDA) levels of rat erythrocyte were investigated. The DMBA-treated group exhibited significant decreases in the levels of erythrocyte GSH-Px, CAT, and GR activities, an increase in MDA levels, and a decrease in total GSH level compared to the control. Se I and Se II fully or partially restored enzyme activity. Lipid peroxidation was also decreased in Se-I- and Se-II-treated groups.     

24-Epibrassinolide ameliorates the effects of boron toxicity on <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> (L.) Heynh by activating an antioxidant system and decreasing boron accumulation

Brassinosteroids (BRs) play a significant role in alleviating the negative effects of various environmental stresses and in promoting the growth and development of plants. In this study, we investigated the effects of 24-epibrassinolide (EBL) on the growth, boron (B) accumulation and activation of the antioxidant system of Arabidopsis thaliana (L.) Heynh exposed to high concentrations of boric acid (BA). A. thaliana plants were grown in a hydroponic culture, and after 4 weeks, the plants were transferred to media containing either 0.80 or 1.60 mM BA. Following BA treatment, 0.01 and 1 µM EBL was sprayed on the entire foliar region of the seedlings. B toxicity induced oxidative stress and considerably inhibited the growth of the plants. The spraying of EBL on the B-treated plants resulted in increases in growth (both fresh and dry shoot mass, silique number, length and mass) and pigment content (total chlorophyll and carotenoids). Excessive B levels increased the activities of antioxidant enzymes, including superoxide dismutase, catalase, ascorbate peroxidase, and guaiacol peroxidase, and increased the proline content in leaves of plants. However, treatment of the B-stressed plants with EBL further enhanced the activities of the antioxidant enzymes and increased the content of proline. The high level of lipid peroxidation in plants observed during exposure to a higher level of BA was decreased following EBL treatment. Thus, this study showed that the exogenous application of EBL ameliorates the toxic effects of B in a model plant by improving the plant’s antioxidant system and decreasing B accumulation. To our knowledge, this is the one of the first studies to examine the effect of BR in plants subjected to B toxicity.     

Expression of a duplicate Na,K-ATPase beta(1)-isoform in the European eel (Anguilla anguilla)

Recent studies on teleost fish have suggested that their genomes have undergone ancient polyploidization events resulting in the duplication of the genome. A duplicate copy of the Na,K-ATPase beta(1)-isoform (called beta(233)) has been identified in the European eel (Anguilla anguilla). The beta(233)-isoform shares high levels of nucleotide (74.8%) and amino acid (69.9%) homology with the eel beta(1)-subunit as well as other vertebrate beta(1)-sequences. Compared with the widely expressed beta(1)-isoform, expression of beta(233)-mRNA is mainly restricted to epithelial tissues. Seawater acclimation induced increases in beta(233)-mRNA levels in kidney, gill, and intestine of migratory "silver" but not the nonmigratory "yellow" adult eels, suggesting that the factors responsible for this upregulation are themselves developmentally regulated. Expression of a variably glycosylated 40- to 52-kDa beta(233)-protein in both gill "chloride" and intestinal epithelial cells suggests that the beta(233)-isoform of Na,K-ATPase may play an important functional role in the major osmoregulatory tissues of euryhaline fish such as the eel.     

The long-term effect of mesh bioprosthesis in inguinal hernia repair on testicular nitric oxide metabolism and apoptosis in rat testis

Polypropylene mesh is the most widely used material in inguinal hernia repair. Although polypropylene mesh is known as an inert material, it is experimentally proven that mesh generates a chronic inflammatory tissue reaction. The aim of the present study was to investigate the long-term effects of polypropylene mesh material used in inguinal hernia operations on testicular function, testicular nitric oxide (NO) metabolism and germ cell-specific apoptosis in rats. The study comprised 40 male rats that were randomly allocated into two groups. In group 1, the left spermatic cord was elevated and a 0.5 x 1 cm polypropylene mesh was placed behind the left inguinal spermatic cord and group 2 consisted of the sham-operated controls. Blood samples were taken at 6 months preoperatively and postoperatively after to assess luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels for hormonal evaluation. Testicular NO was evaluated by the Griess method, apoptosis by a TUNEL method and inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) expressions by immunohistochemical staining. Mild (+) eNOS expression was observed in all specimens. Mild (+) iNOS expression was only detected in ipsilateral testis of the mesh-implanted study group. Apoptotic cells were not detected in any samples. We are of the opinion that long-term polypropylene mesh implantation has no effect on testicular hormonal function and only a limited effect on nitric oxide levels and this effect is not sufficient to cause apoptosis in testis that could lead to infertility. It seems that mesh implantation is a reliable method in inguinal hernia repair; however, further work is required by more sensitive methods to fully elucidate the potential testicular damage.     

Low frequency of infertility among workers in a borate processing facility

In order to rule out the possibility of omitting some individuals in the study at field visits described in previous articles, either because of the reluctance of the subject or because of his appointment elsewhere, fertility and infertility states of borate workers of the Borax and Acid Plants in Bandirma, Balikesir are given. Balikesir is one of the four provinces with large borate deposits of Turkey, and Bandirma is 1 of its 19 districts. This county is relatively far away from borate deposits, and drinking water piped out through the springs has a boron amount between 0.10 and 0.82 ppm B. That the participants are occupationally exposed to the mineral in essence is therefore conceivable. At the first phase of the investigation, 191 workers were interviewed, as detailed previously. Among these, there were six infertiles of the primary type with a rate 3.1%. Boron-unrelated infertile couples among sibs were found to be 2.6–3.6%, and 3.2% for three-generation marriages—none being higher than those revealed in different sets of controls. In the second stage of work, computerized files of all workers of the facility and all employees of the general management sharing the same location were checked without an interview. Twenty-four subjects (3.4%) out of 712 workers were childless versus 2.7% among 108 employees, and 2.2% among 91 workers of a distantly located sulfuric acid plant of the same complex. The differences were not significant, and these recent findings support the conclusion already reached almost unambiguously that boron exposure at the present levels does not interfere with human reproduction.