Protection of a lens of an eye against the simulated diabetic cataract

Катаракта является очень распространенным осложнением при диабете. Мы подвергли бычие линзы действию высокой концентрации глюкозы (450 мг.%) в условиях культуры в течение двух недель и исследовали повреждения в линзе и возможную защиту специальными антиоксидантами N ацетил L цистеином (NAC) и цинковым комплексом desferrioxamine (DFO), селективным хелатором для железа. Исследовалось оптическое качество линз и окисление эпителия с дихлорфлюоресцеином (DCF), а также оценивались изменения в 2D гель электрофоретическом профиле белков хрусталика. Наблюдались изменения при высоком содержании глюкозы в фокусном расстоянии линзы, повышении окисления. NAC И Zn DFO почти полностью защищали линзы; DFO показывал только частичную защиту. Результаты демонстрировали, что антиоксиданты могут защищають хрусталик повреждающего действия высоких концентраций глюкозы. Комбинация NAC и ZnDFO действовала более эффективно.Катаракта є дуже поширеним ускладненням при діабеті. Ми піддали кришталик ока бика дії високої концентрації глюкози (450 мг %) в умовах культури протягом двох тижнів і досліджували пошкодження в лінзі і можливий захист спеціальними антиоксидантами N ацетил L цистеином (NAC) і цинковим комплексом desferrioxamine (DFO), селективним хелатором для заліза. Досліджувалася оптична якість лінз і окислення епітелію з дихлорфлюоресцеїном (DCF), а також оцінювалися зміни в 2D гель електрофоретичному профілі білків кришталика. Спостерігалися зміни при високому вмісті глюкози у фокусній відстані лінзи, підвищенні окислення. NAC І Zn DFO майже повністю захищали лінзи; DFO показував тільки частковий захист. Результати демонстрували, що антиоксиданти можуть защищають кришталик від ушкоджувальної дії високих концентрацій глюкози. Комбінація NAC і ZNDFO діяла ефективніше

Ovarian metabolism of xenobiotics

At birth, the mammalian ovary contains a finite number of primordial follicles, which once depleted, cannot be replaced. Xenobiotic exposures can destroy primordial follicles resulting in premature ovarian failure and, consequently, early entry into menopause. A number of chemical classes can induce premature ovarian failure, including environmental, chemotherapeutic and industrial exposures. While our knowledge on the mechanistic events that occur in the ovary with chemical exposures is increasing, our understanding of the ovary\u27s capacity to metabolize such compounds is less established. This review will focus on three chemicals for which information on ovarian metabolism is known: trichloroethylene, 7,12-dimethylbenz[a]anthracene and 4- vinylcyclohexene. The current state of understanding of ovarian bioactivation and detoxification processes for each will be described

Antioxidant activity of aminodiarylamines in the thieno[3,2-b]pyridine series: radical scavenging activity, lipid peroxidation inhibition and redox profile

The antioxidant activity of the aminodi(hetero)arylamines, prepared by C-N coupling of the methyl 3-aminothieno[3,2-b]pyridine-2-carboxylate with bromonitrobenzenes and further reduction of the obtained nitro compounds, was evaluated by chemical, biochemical and electrochemical assays. The aminodi(hetero)arylamine with the amino group ortho to the NH and a methoxy group in para, was the most efficient in radical scavenging activity (RSA, 63 µM) and reducing power (RP, 33 µM), while the aminodiarylamine with the amino group in para to the NH, gave the best results in β-carotene-linoleate system (41 µM) and inhibition of formation of thiobarbituric acid reactive substances in porcine brain cells homogenates (7 µM), with EC50 values even lower than those obtained for the standard trolox. This diarylamine also presented the lowest oxidation potential, lower than the one of trolox, and the highest antioxidant power in the electrochemical assays. The para substitution with an amino group enables higher antioxidant potential.The authors are grateful to FCT and FEDER (European Fund for Regional Development)-COMPETE/QREN/EU for financial support through the research unities PEst-C/QUI/UI686/2011 and PEst-OE/AGR/UI0690/2011, the research project PTDC/QUI-QUI/111060/2009 and the post-Doctoral grant attributed to R.C.C. (SFRH/BPD/68344/2010)

Reducing antioxidant capacity evaluated by means of a controlled potential oxidative attack

An analytical method suitable for an antioxidant sensor is presented following the response of these substances to an extensive oxidative attack imposed by electrochemical means. The electrochemical assay simulates the action of a reactive oxygen species (ROS) by means of electrolyses carried out at a potential which is settled at the formal potential of the ROS. The antioxidant activities of trolox and ascorbic, gallic and caffeic acids and of mixtures these antioxidants was estimated from the charge required for the complete oxidation of the antioxidants from assays where the oxidative attack by O2 and by O2 were simulated.Fundação para a Ciência e Tecnologia (FCT)Centro de Química da Universidade do Minh

Evaluation of Cholinesterase Activities During in Vivo Intoxication Using an Electrochemical Sensor Strip – Correlation With Intoxication Symptoms

Cholinesterase activity in blood of laboratory rats was monitored. Rats were intoxicated with paraoxon at dosis of 0 – 65 – 125 – 170 – 250 – 500 nmol. The 250 nmol dose was found to be the LD50. An electrochemical sensor was found useful to provide information about cholinesterase activity. The decrease of cholinesterase activity was correlated to intoxication symptoms and mortality level. It was found that the symptoms of intoxication are not observed while at least 50% of cholinesterase activity in blood remains. The minimal cholinesterase activity essential to survival is around 10%, when compared with the initial state. No changes in levels of low moleculary weight antioxidants were observed

Injury Induced by Chemical Warfare Agents: Characterization and Treatment of Ocular Tissues Exposed to Nitrogen Mustard

PURPOSE. Mustard agents are highly toxic and abundant warfare chemicals, primarily affecting ocular tissues, with no specific treatment antidote. The purpose of the present study was to examine the efficacy of novel metallocomplexes, known to inhibit the formation of highly reactive free radicals, to reduce ocular injury induced by nitrogen mustard (NM). METHODS. One eye in each of 72 rabbits was exposed to 1% to 2% NM. Topical treatment with eye drops of a metallocomplex-either zinc-or gallium-desferrioxamine (Zn/DFO and Ga/DFO)-was compared with treatment with saline, zinc (chloride), or DFO alone. Examiners masked to the treatment groups assessed the extent of ocular injury and the response to treatment using clinical, histologic, and biochemical criteria. RESULTS. Exposure to NM followed by administration of carrier alone (saline) caused severe and long-lasting injury to ocular anterior segment structures. Treatment with either Zn/DFO or Ga/DFO yielded marked protection (52%-64%), including faster healing of corneal epithelial erosions, less scarring and neovascularization, decreased inflammation in the anterior chamber, better maintenance of intraocular pressure, and less severe changes in the iris and lens. These were also associated with better preservation of systemic antioxidant status. Zinc or DFO alone afforded lower levels of protection. No toxic effects of these complexes were observed. CONCLUSIONS. It is suggested that Zn/DFO or Ga/DFO, by virtue of their enhanced ability to infiltrate cells and inhibit transition metal-dependent formation of free radicals through the combined push-pull mechanism, be considered as a basis for treatment of mustard injuries. (Invest Ophthalmol Vis Sci