Claiton L. Lencina

Neuroprotective and antioxidant effects of curcumin in a ketamine-induced model of mania in rats

Bipolar disorder (BD) is a chronic and debilitating illness characterized by recurrent manic and depressive episodes. Our research investigates the protective effects of curcumin, the main curcuminoid of the Indian spice turmeric, in a model of mania induced by ketamine administration in rats. Our results indicated that ketamine treatment (25 mg/kg, for 8 days) induced hyperlocomotion in the open-field test and oxidative damage in prefrontal cortex (PFC) and hippocampus (HP), evaluated by increased lipid peroxidation and decreased total thiol content. Moreover, ketamine treatment reduced the activity of the antioxidant enzymes superoxide dismutase and catalase in the HP. Pretreatment of rats with curcumin (20 and 50 mg/kg, for 14 days) or with lithium chloride (45 mg/kg, positive control) prevented behavioral and pro-oxidant effects induced by ketamine. These findings suggest that curcumin might be a good compound for preventive intervention in BD, reducing the episode relapse and the oxidative damage associated with the manic phase of this disorder.

Eugenol derivatives as potential anti-oxidants: is phenolic hydroxyl necessary to obtain an effect?

Eugenol, obtained from clove oil (Eugenia caryophyllata), possess several biological activities. It is anti‐inflammatory, analgesic, anaesthesic, antipyretic, antiplatelet, anti‐anaphylactic, anticonvulsant, anti‐oxidant, antibacterial, antidepressant, antifungal and antiviral. The anti‐oxidant activity of eugenol have already been proven. From this perspective testing, a series of planned structural derivatives of eugenol were screened to perform structural optimization and consequent increase of the potency of these biological activities.

Antidepressant-like effects of aqueous extract from Cecropia pachystachya leaves in a mouse model of chronic unpredictable stress

Chronic stressful stimuli influence disease susceptibility to depression, cardiovascular, metabolic and neurodegenerative disorders. The present work investigated antidepressant and antioxidant properties of the aqueous extract from Cecropia pachystachya in a mouse model of chronic unpredictable stress (CUS). Our results indicated that acute administration of the aqueous extract (AE) from C. pachystachya (200 and 400mg/kg, p.o.) produced an antidepressant-like effect in the forced swimming test (FST). The chronic treatment with C. pachystachya extract (200mg/kg, p.o., for 14 days) prevented the depressant-like effect but not the anxiogenic effect induced by CUS. In addition to the behavioral modifications, the 14 days of CUS increased lipid peroxidation in the hippocampus (HP) and prefrontal cortex (PFC), decreased total thiol content and glutathione peroxidase activity in the HP. C. pachystachya AE administration during CUS protocol was able to prevent the oxidative damage induced by stress. However, no changes were observed in the activity of the antioxidant enzymes superoxide dismutase and catalase in the above cited brain areas after the stress protocol and treatment. Our results suggest that C. pachystachya prevented both depressive behavior and oxidative damage induced by CUS, supporting its neuroprotective potential against behavioral and biochemical dysfunctions induced by chronic stress.

Green juice as a protector against reactive species in rats

INTRODUCTION Green juice is popularly known for introducing antioxidants, improving intestinal function and reducing weight gain. OBJECTIVES In the present study we determine the antioxidant effect of green juice comparing it with orange juice. METHODS Rats were divided into three experimental groups and submitted to supplementation for 15 days: the (GJ) group received green juice, the (OJ) group received orange juice and the control group received water. We evaluated the antioxidant activity and total phenolic content of green and orange juices, as well as rat weight gain. We also investigated some oxidative stress parameters, namely thiobarbituric acid-reactive substances (TBARS), superoxide dismutase and catalase in rat cerebral cortex. RESULTS AND DISCUSSION Results showed that GJ had significantly less weight gain than the control group. With respect to antioxidant activity screening, the remaining percentage of DPPH at dilutions 1:10, 1:100 and 1:1000 of green juice was 22.8%, 58% and 78%, and orange juice, at the same dilutions, was 5.6%, 5.6% and 77.2%, respectively. The ability of juices to reduce the ABTS radical was 3.5 mmol trolox/L for green juice and 5.2 mmol trolox/L for orange juice. Additionally, the green juice did not present any difference in total phenolic acid content when compared to orange juice. TBARS were reduced in GJ and OJ. Besides, GJ supplementation decreased catalase activity. In conclusion, our data showed that green juice reduced weight gain, lipoperoxidation and catalase activity, suggesting that this supplementation may have a protective effect against reactive species.

Influence of physical exercise and gender on acetylcholinesterase and butyrylcholinesterase activity in human blood samples

The determination of cholinesterase activity in plasma and erythrocytes serves as a useful and sensitive biomarker of exposure to organophosphorus and carbamate pesticides. However, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity may be influenced by factors such as age, gender, drugs, and physical exercise. The aim of this study was to evaluate the effects of gender and physical exercise on the activity of AChE and BuChE in healthy individuals. The values for both enzymes were lower for women. Physical exercise increased the levels of BuChE, and had no significant effect on AChE. To our knowledge, this is the first clinical study evaluating the influence of physical exercise in levels of these enzymes. Considering that cholinesterase activity is a useful parameter in assessing the exposure of individuals to pesticides, it is important to understand factors that influence the determination of the enzymes in order to avoid the erroneous interpretation of results.

Antimicrobial and cytotoxic evaluation of eugenol derivatives

Eugenol is the major phenolic component of clove essential oil and it has been used in medical and dental practice for its properties like analgesic, local anesthetic, and antioxidant. It is known that eugenol can denature proteins and react with cell membrane phospholipids changing their permeability and inhibiting a great number of Gram-negative and Gram-positive bacteria as well as different types of yeast. Eugenol has ever demonstrated antimicrobial properties; thus, the search for the optimization through structural changes appears to be interesting for the development of new antimicrobials. This study aimed to evaluate the antimicrobial activity and cytotoxic characteristics of eugenol analogs. From natural eugenol, 14 derivatives were obtained by typical acylation and alkylation. Their antimicrobial activity was evaluated by the broth microdilution method. The compounds were assessed against Staphylococcus aureus ATCC 19095, Enterococcus faecalis ATCC 4083, Escherichia coli ATCC29214, Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 62342 and the following clinical isolates from the human oral cavity: C. albicans (3), C. parapsilosis C. glabrata C. lipolytica, and C. famata. Cytotoxicity against mouse embryonic fibroblast (NIH/3T3) cell line was evaluated by MTT colorimetric assay. The majority of compounds demonstrated significant antimicrobial activities. In general, the compounds presented very low or no cytotoxicity, with an inhibitory ratio lower than 50 % against NIH/3T3 cell line.

Preventive effects of blueberry extract on behavioral and biochemical dysfunctions in rats submitted to a model of manic behavior induced by ketamine

The aim of the present study was to evaluate the protective effects of blueberry extract on oxidative stress and inflammatory parameters in a model of mania induced by ketamine administration in rats. Male rats were pretreated with blueberry extract (200mg/kg, once a day for 14days), lithium chloride (45mg/kg, mood stabilizer used as a positive control, twice a day for 14days), or vehicle. Between the 8th and 14th days, rats also received an injection of ketamine (25mg/kg) or vehicle. In the 15th day, thirty minutes after ketamine administration the hyperlocomotion of the animals was assessed in the open - field apparatus. Immediately after the behavioral analysis brain and blood were collected for biochemical determinations. ketamine treatment induced hyperlocomotion and oxidative damage in cerebral cortex, hippocampus and striatum such as an increase in lipid peroxidation and a decrease in the antioxidant enzymes activities (superoxide dismutase, catalase e glutatione peroxidase). Ketamine administration also increased the IL-6 levels in serum in rats. Pretreatment of rats with blueberry extract or lithium prevented the hyperlocomotion, pro - oxidant effects and inflammation induced by ketamine. Our findings suggest that blueberry consumption has a neuroprotective potential against behavioral and biochemical dysfunctions induced in a preclinical model that mimic some aspects of the manic behavior.

Anti-Candida, Anti-Enzyme Activity and Cytotoxicity of 3,5-Diaryl-4,5-dihydro-1H-pyrazole-1-carboximidamides

Because of the need for more effective and less harmful antifungal therapies, and interest in the synthesis of new carboximidamides, the goal of this study was to determine the antifungal and anti-enzyme activities of some new pyrazole carboximidamides and their cytotoxicity. For this purpose, tests were performed to evaluate: minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC); production of proteinases and phospholipase, and cytotoxicity of the extracts. Data were analyzed by ANOVA and Tukey Tests (α = 5%). The results were: MIC and MFC ≥ 62.5 μg/mL (C. albicans, C. parapsilosis, C. famata, C. glabrata, and Rhodotorula mucillaginosa) and MIC and MFC ≥ 15.6 μg/mL (C. lipolytica). The values of proteinase and phospholipase (Pz) of C. albicans before and after exposure to the compounds were: 0.6 (±0.024) and 0.2 (±0.022) and 0.9 (±0.074) and 0.3 (±0.04), respectively. These proteinase results were not significant (p = 0.69), but those of phospholipase were (p = 0.01), and 15.6 μg/mL was the most effective concentration. The cytotoxicity means were similar among the tests (p = 0.32). These compounds could be useful as templates for further development through modification or derivatization to design more potent antifungal agents. Data from this study provide evidence that these new pyrazole formulations could be an alternative source for the treatment of fungal infections caused by Candida. However, a specific study on the safety and efficacy of these in vivo and clinical trials is still needed, in order to evaluate the practical relevance of the in vitro results.

Ultrasound assisted efficient conversion of aromatic aldehydes from oximes

This work describes the ultrasound-assisted regeneration of aldehydes from oximes in ethanol and phosphoric acid as mediator of the reaction. The large scale regeneration of benzaldehyde was shown under similar conditions. The products were isolated in good yields after short reaction times under mild conditions.

Pharmacological application of antiradical compound properties.

The reactive species are part of normal human metabolism and are involved in many physiological mechanisms. However, when reactive species are overproduced and antioxidant defenses are insufficient to control oxidation, an unbalance can occur, leading to cellular oxidative damage. This injury has been associated with many diseases including inflammation, cancer, cardiovascular disease, diabetes, and neurodegenerative diseases. The population is ageing and chronic diseases affect millions of people around the world. Thus more effective treatments are necessary to provide improved quality of life for individuals. In this context, there has been growing interest in research involving natural and synthetic antioxidants which can emerge as alternative therapy and/or prevention of various chronic degenerative diseases. In this special issue, we presented 11 original research papers and 3 review articles that describe the antiradical compound properties. The original papers explored in this special edition include a wide variety of topics such as natural products against injury (A. A. Soares et al. and S. Murthy et al.), antioxidant properties of natural products (E. Gregoris et al., A. Hashim et al., and A. Zajdel et al.), effect of glutathione on immune system (D. Morris et al.), antioxidant mechanism of buckminsterfullerene C60 (V. A. Chistyakov et al.), and spin labeled analogues of anticancer drugs in prevention of injury (V. Gadjeva et al.). The review articles discuss the role of antioxidants in chronic diseases: cardioprotective effect of vitamins (R. Rodrigo et al.), antidiabetic potential of curcumin analogues (Y. Son et al.), and detrimental and protective effects of fructose (H. M. Semchyshyn). We believe that a better understanding of action of natural and synthetic antioxidants may contribute to the development of a new therapeutic approach in many different diseases, improving the patients quality of life.