Background: Oxidative stress, caused by an imbalance in reactive oxygen species produced during normal cell metabolism and/or deficiency of scavenger antioxidant defense, has been implicated in the pathology of several human diseases, including endocrine diseases of thyroid gland. Aim of the work: The aim of this study is to evaluate the serum levels of malondialdehyde (MDA), a product of lipid peroxidation, and the antioxidant enzymatic activities of superoxide dismutase (SOD) and catalase (CAT) as well as the total antioxidant capacity (TAC) in overt and subclinical hypothyroidism. Subjects and methods: Forty eight newly diagnosed hypothyroid patients, 24 patients of them have subclinical hypothyroidism (SHT) while the other 24 patients have overt hypothyroidism (OHT), as well as 24 healthy euthyroid control subjects were enrolled in this cross sectional study. Laboratory investigations including lipid profile, thyroid functions as well as levels of serum MDA, SOD, catalase and TAC were estimated. Results: Both OHT and SHT patients had significantly higher serum TSH, total cholesterol (TC), triglycerides (TGs), LDL-C, catalase, SOD and MDA levels as well as significantly lower serum HDL-C and TAC levels when compared to euthyroid control subjects. The correlation study revealed that serum TSH levels were significantly positively correlated with TC, LDL-C and TGs serum levels and significantly negatively correlated with HDL-C levels. Moreover, serumMDA, CAT and SOD levels showed significantly positive correlation with TSH, TC, LDL-C and TGs serum levels and a significant negative correlation with free T4, free T3 and HDL-C serum levels.Furthermore, TAC levels showed a significant positive correlation with free T4, free T3 and HDL-C serum levels and a negative correlation with TSH, TC, TGs and LDL-C serum levels. Conclusions:The present study demonstrated that patients with both OHT and SHT showed increased lipid peroxidation and oxidative stress which was evidenced by the increased levels of MDA, a lipid peroxidation product, and the induction of SOD and CAT antioxidantenzymatic activities. Increased MDA and other free radical production could overload the antioxidant system resulting in consumption and severe depletion of antioxidants with concomitant reduction in total antioxidant capacity.Copy Right, IJAR, 2016,. All rights reserved.

Downy mildew of squash caused by Pseudoperonospora cubensis is considered one of the serious diseases that affect cucurbits crops in Egypt and all the world. This study was conducted to find alternative safe methods for controlling downy mildew disease. The use of plant extracts, essential oils, growth regulators and foliar fertilization with nitrogen, potassium and phosphorus showed that these treatments reduce disease incidence and lead to a significant increase in yield compared to untreated plants. Growth characteristics of squash plants i.e., plant height, leaf area, root length, shoot length, plant fresh weight and plant dry weight were significantly increased in response to the application of any tested control methods compared to the untreated control plants. Total water content (TWC), relative water content (RWC) and transpiration rate of squash plants were remarkably increased in response to the application of either Gibberellin, black cumin oil, clove oil (10%), mint oil (5%), Thuja extract and/or the fungicide in comparison with the untreated control. Application of the disease control methods to squash plants increased chlorophyll, total sugars content and proline concentration compared to the untreated control plants.

Grapes powdery mildew disease caused by Uncinula necator (Schw.) is one of the most critical diseases attacking grapes fruits, buds and leaves causing considerable yield losses. This study compared the effectiveness of three antioxidants on powdery mildew disease (ascorbic acid, citric acid and boric acid) in controlling the powdery mildew of grapes. The antioxidants were significantly better improving disease control and fruit yield production of grapes than the control. Ascorbic acid and citric acid were the most effective antioxidants on powdery mildew disease and increasing the yield.