Oxidative stress from generation of increased reactive oxygen species or has been reported to play an important role in dementia. Oxidative stress due to free radicals of oxygen or reactive oxygen species could be precipitating factors in the etiology of dementia. Apomorphine has been reported to have neuroprotective effects. To monitor memory enhancing and neuroprotective effects of apomorphine, we determined the antioxidant enzymes activities, lipid peroxidation, acetylcholine esterase (AChE) activity in brain and plasma, following repetitive administration of apomorphine in rat model of dementia. Biogenic amine levels were also monitored in hippocampus. Repeated administration of scopolamine was taken as an animal model of dementia. Decreased glutathione peroxidase, superoxide dismutase and catalase activities were observed in these animal models of dementia. While increased lipid peroxidation was also observed in the brain and plasma samples. The results showed significant effects of apomorphine. The activities of antioxidant enzymes displayed increased activities in both brain and plasma. Glutathione peroxidase and catalase activities were found to be significantly higher in brain and plasma of apomorphine treated rats. Superoxide dismutase (SOD) was significantly decreased in plasma of scopolamine injected rats; and a decreased tendency (non-significant) of SOD in brain was also observed. AChE activity in brain and plasma was significantly decreased in scopolamine treated rats. Learning and memory of rats in the present study was assessed by Morris Water Maze (MWM). Short-term memory and long-term memory was impaired significantly in scopolamine treated rats, which was prevented by apomorphine. Moreover, a marked decrease in biogenic amines was also found in the brain of scopolamine treated rats and was reverted in apomorphine treated rats. Results showed that scopolamine-treatment induced memory impairment and induced oxidative stress in rats as compared to saline-treated controls. These impairments were significantly restored by apomorphine administration. In conclusion, our data suggests that apomorphine at the dose of 1 mg/kg could be a potential therapeutic agent to treat dementia and related disorders.

UNASSIGNED: Recurrent Aphthous Stomatitis (RAS) is a common oral mucosal disorder that affects 20% of the population worldwide. Factors such as trauma, stress, genetic, hypersensitivity, nutrition, immune disturbance and hormonal imbalance may disturb the oxidant and antioxidant balance of an organism and precipitate RAS, but the relationships are poorly understood.
UNASSIGNED: The purpose of this study was to evaluate the antioxidant status in plasma and saliva of patients with RAS.
UNASSIGNED: Forty patients with RAS and forty healthy individuals were included in the study. The levels of antioxidants such as Superoxide Dismutase (SOD), Glutathione Peroxidase (GSHPx) Catalase (CAT) and Uric Acid (UA) were measured in plasma and saliva. Statistical analysis was performed to compare the two groups using independent t-test and ANOVA.
UNASSIGNED: Decreased SOD levels were observed in plasma amongst RAS patients (p < 0.03) whereas, increased levels were observed in their saliva (p < 0.001) compared to the control group. A significant difference (p < 0.001) was noticed in GSHPx levels: RAS patients exhibited higher levels in plasma but decreased in saliva compared to the control group. CAT activities and UA levels in saliva (p = 0.015 and p < 0.001 respectively) were observed to be significantly higher in RAS patients. Within the RAS group elevated plasma SOD level (p < 0.006) was found in patients with major ulcers whereas, an increased plasma UA (p < 0.01) level was observed in patients with minor ulcers.
UNASSIGNED: The non-equilibrium antioxidant levels observed in both plasma and saliva indicate the antioxidant status of the body is disturbed in patients with RAS.

BACKGROUND: Rheumatoid arthritis is a chronic, autoimmune and systemic inflammatory disease, which targets synovial joints leading to joint destruction mediated in part by migration of inflammatory cells into the synovial tissue.
OBJECTIVE: The present study evaluates the anti-rheumatic effect of a methanol extract of Ananas comosus (L.) Merr. (Bromeliaceae) peel in rats.
METHODS: Anti-rheumatic activity of crude extract of peels of A. comosus in complete Freund\'s induced arthritis model in rats was studied at doses of 50, 100, 250 and 500 mg/kg b.w. for 21 days. Parameters such as paw size, levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), C-reactive proteins (CRP) and prostaglandins (PGE2) were analysed.
RESULTS: Oral administration of the extract significantly reduced the swelling in the paw of rats (EC50 65.1 ± 2.95 mg/kg b.w.) with a maximal inhibition of 77.01 ± 10.53% on 21st day at 500 mg/kg b.w. The extract also significantly reduced the levels of SOD, CAT and GPx in liver (EC50 26.84 ± 16.37, 68.37 ± 19.22, 106.54 ± 34.81 mg/kg b.w., respectively), kidney (EC50 261.75 ± 81.5, 176.38 ± 8.08, 14.32 ± 6.64, mg/kg b.w., respectively) and spleen (EC50 152.14 ± 39.57, 83.97 ± 14.6, 47.1 ± 10.45 mg/kg b.w., respectively); and CRP (EC50 36.37 ± 12.4 mg/kg b.w.) and PGE2 (EC50 191.06 ± 71.54 mg/kg b.w.) in tissue homogenate and serum, respectively, at 500 mg/kg b.w. as compared to arthritic control group.
CONCLUSIONS: These results suggest that A. comosus fruit peel extract exerts anti-rheumatic activity.

The thioredoxin (Trx) system, which is composed of NADPH, thioredoxin reductase (TrxR), and thioredoxin, is a key antioxidant system in defense against oxidative stress through its disulfide reductase activity regulating protein dithiol/disulfide balance. The Trx system provides the electrons to thiol-dependent peroxidases (peroxiredoxins) to remove reactive oxygen and nitrogen species with a fast reaction rate. Trx antioxidant functions are also shown by involvement in DNA and protein repair by reducing ribonucleotide reductase, methionine sulfoxide reductases, and regulating the activity of many redox-sensitive transcription factors. Moreover, Trx systems play critical roles in the immune response, virus infection, and cell death via interaction with thioredoxin-interacting protein. In mammalian cells, the cytosolic and mitochondrial Trx systems, in which TrxRs are high molecular weight selenoenzymes, together with the glutathione-glutaredoxin (Grx) system (NADPH, glutathione reductase, GSH, and Grx) control the cellular redox environment. Recently mammalian thioredoxin and glutathione systems have been found to be able to provide the electrons crossly and to serve as a backup system for each other. In contrast, bacteria TrxRs are low molecular weight enzymes with a structure and reaction mechanism distinct from mammalian TrxR. Many bacterial species possess specific thiol-dependent antioxidant systems, and the significance of the Trx system in the defense against oxidative stress is different. Particularly, the absence of a GSH-Grx system in some pathogenic bacteria such as Helicobacter pylori, Mycobacterium tuberculosis, and Staphylococcus aureus makes the bacterial Trx system essential for survival under oxidative stress. This provides an opportunity to kill these bacteria by targeting the TrxR-Trx system.

Lippia citriodora (lemon verbena) has been widely used in folk medicine for its pharmacological properties. Verbascoside, the most abundant compound in this plant, has protective effects associated mostly with its strong antioxidant activity. The purpose of this study was to test the effect of L. citriodora extract intake on the antioxidant response of blood cells and to correlate this response with the phenolic metabolites found in plasma. For this purpose, firstly the L. citriodora extract was characterized and its radical scavenging activity was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Then, catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GRed) activities were determined in lymphocytes, erythrocytes, and neutrophils isolated from rats after acute intake of L. citriodora. Phenolic metabolites were analyzed in the same plasma samples by HPLC-ESI-TOF-MS. Myeloperoxidase (MPO) activity in neutrophils, which has been proposed as a marker for inflammatory vascular damage, was also determined. After L. citriodora administration, the antioxidant enzymes activities significantly accelerated (p<0.05) while MPO activity subsided, indicating that the extract protects blood cells against oxidative damage and shows potential anti-inflammatory and antiatherogenic activities. The main compounds found in plasma were verbascoside and isoverbascoside at a concentration of 80±10 and 57±4 ng/ml, respectively. Five other metabolites derived from verbascoside and isoverbascoside were also found in plasma, namely hydroxytyrosol, caffeic acid, ferulic acid, ferulic acid glucuronide, and homoprotocatechuic acid, together with another eight phenolic compounds. Therefore, the phenylpropanoids verbascoside and isoverbascoside, as well as their metabolites, seem to be the responsible for the above-mentioned effects, although the post-transcriptional activation mechanism of blood-cell antioxidant enzymes by these compounds needs further investigation.