Vanessa Rodrigues Coelho

Gamma-decanolactone inhibits iNOS and TNF-alpha production by lipopolysaccharide-activated microglia in N9 cells

Activated microglia that produce reactive nitrogen species (RNS), inflammatory factors, reactive oxygen species (ROS), and other neurovirulent factors may lead to the development of neurodegenerative diseases. Certain compounds can inhibit the activation of microglia. However, these mechanisms remain unclear. In the present study, we investigated the inhibitory effect of Gamma-decanolactone (GD) on the production of reactive oxygen species and inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS) - stimulated N9 murine microglial cells through the p38 MAPK signaling pathway. The results showed that GD attenuated the activation of N9 cells and inhibited intracellular reactive oxygen species and the expression of iNOS and TNF-α induced by LPS in the cells. In addition, GD blocked the phosphorylation of p38 and inhibited cleaved caspase-9 and DNA damage. These data indicate that GD has therapeutic potential for the treatment of neurodegenerative diseases, and that it exerts its effects by inhibiting inflammation.

Manual acupuncture improves parameters associated with oxidative stress and inflammation in PTZ-induced kindling in mice

The use of acupuncture in the treatment of central nervous system (CNS) disorders is an age-old practice. Although only a few studies have proved its efficacy, evidence has indicated the use of acupuncture to treat different types of seizures. Therefore, the present study aimed to evaluate the effect of manual acupuncture (MAC) using the chemical kindling model. The role of MAC in oxidative stress and inflammation after pentylenetetrazole (PTZ)-induced kindling was investigated by measuring reactive oxygen species (ROS) production, superoxide dismutase (SOD), and catalase (CAT) activities, nitrite content, and deoxyribonucleic acid (DNA) damage in cerebral cortex. Mice received PTZ (60mg/kgs.c.) once every three days for 16days, totaling six treatments. MAC was applied at acupoint GV20 daily during the entire experimental protocol. Diazepam (DZP) (2mg/kg) was used as positive control. Also, we evaluated the MAC effect associated with DZP (MAC/DZP) at a low dose (0.15mg/kg). The results demonstrated that MAC or MAC/DZP were not able to reduce significantly seizure occurrence or to increase the latency to the first seizure during treatment. MAC/DZP promoted a difference in the first latency to seizure only on the third day. PTZ-induced kindling caused significant neuronal injury, oxidative stress, increased DNA damage, nitric oxide production, and expression of the pro-inflammatory Tumor Necrosis Factor-α (TNF-α). These effects were reversed by treatment with MAC or MAC/DZP. These results indicated that the stimulation of acupoint GV20 by MAC showed no potential antiepileptogenic effect in the model used, although it greatly promoted neuronal protection, which may result from antioxidant and anti-inflammatory effects observed here.

Citrus essential oils inhalation by mice: Behavioral testing, GCMS plasma analysis, corticosterone, and melatonin levels evaluation

The use of orange essential oils (EOs) as a complementary treatment is very common in Brazilian popular culture. The levels of melatonin (MEL) and corticosterone (CORT) hormones were investigated simultaneously, by the Luminex™ immunoassay system in mice plasma, after Citrus aurantium and Citrus sinensis EOs inhalation for 30 min. The plasma was analyzed by headspace through gas chromatography coupled to mass spectrometry for investigation of the EO components. Mice were submitted to behavioral testing to research anxiolytic‐like, sedative, and antidepressant‐like effects. The inhalation of atmosphere obtained from vaporization of 10% solution of this Citrus EO separately did not affect MEL or CORT plasma levels; that is, the MEL and CORT levels did not present variation in function of the EO in the schedule used. On the other hand, the imipramine positive control used altered the level of MEL as expected. The EO constituents were detected in plasma at different ratios that is present in inhaled EO. Behavioral tests showed that the inhalation of 10% C. sinensis EO presents an anxiolytic‐like and sedative effect. Thus, C. sinensis EO can be a valuable tool for treatment of the anxiety disturbs, apparently without interference with MEL and CORT physiological levels.

Effect of operational parameters and Pd/In catalyst in the reduction of nitrate using copper electrode

ABSTRACT Water with high concentration of nitrate may cause damage to health and to the environment. This study investigated how concentration, current density, flow, pH, the use of Pd/In catalyst and operating mode (constant current density and constant cell potential) have an influence in the electrochemical reduction of nitrate and in the formation of gaseous compounds using copper electrode. Experiments were performed in two-compartment electrolytic cells separated by a cationic membrane with nitrate model solutions prepared as a surrogate of concentrated brines from membrane desalination plants. The results show that the electroreduction process has potential for reduction of nitrate and that it is influenced by the operational conditions. The best conditions found for the treatment – with satisfactory reduction of nitrate, formation of gaseous compounds and reproducibility – were at nitrate concentrations of 600 and 1000 mg L−1, current density of 1.1 mA cm−2 and without pH control, since in these conditions the production of gaseous compounds is higher than the production of nitrite. When Pd/In catalyst was used, the nitrate reduction was 50% after 6 h of experiment and the predominant product were gaseous compounds. When compared to the experiment without the catalyst, the arrangement with Pd/In was the most efficient one.

Neuropharmacological Profile of Gamma-Decanolactone on hemically-induced Seizure in Mice

BACKGROUND Gamma-decanolactone (GD) is a monoterpene compound that presents anticonvulsant effect in acute and chronic models of epilepsy and it acts as a noncompetitive glutamate antagonist. OBJECTIVE This study evaluated the anticonvulsant profile and the possible mechanism of action of GD in seizures induced by isoniazid (INH; 250 mg/kg), picrotoxin (PCT; 5 mg/kg) and 4-aminopyridine (4-AP; 13 mg/kg) in male mice. METHOD Thirty minutes before the convulsants administration, animals received a single administration of saline, GD (100 or 300 mg/kg) or the positive control diazepam (DZP; 2 mg/kg). The parameters evaluated were the latency to the first seizure and the occurrence of clonic forelimb seizures. The rotarod performance test was used to evaluate the neurotoxicity of GD (300 mg/kg). Also, the DZP-induced sleep test was used. RESULTS DZP increased the latency to the first seizure on all used models and decreased the percentage of seizures in two of the three behavioral models. GD was able to prolong the latency to the first seizure and decreased the percentage of seizures induced by INH and 4-AP, but not by PCT. It reduced the latency to fall off the rotarod test only at the time of 30 min. In the DZP-induced sleep test, GD shortened the onset and prolonged the time of sleep. CONCLUSION Our findings suggested that GD reduced the convulsive behavior in the seizure models used here and it could modulate GABA pathways and affect potassium channels directly or indirectly, involving more than one cellular target in the central nervous system.

A 28-day Sub-acute Genotoxic and Behavioural Assessment of Garcinielliptone FC

Garcinielliptone FC (GFC) is a polyisoprenylated benzophenone isolated from Platonia insignis Mart (Clusiaceae) with promising anticonvulsant properties. However, its safe use and other effects on the central nervous system require assessment. This study assessed the toxicological effects of GFC using the comet assay and the micronucleus test in mice treated for 28 days. A behavioural model was employed to detect possible injuries on the central nervous system. Mice treated with GFC (2, 10 and 20 mg/kg; i.p.) daily for 28 days were submitted to rotarod test, open‐field test and tail suspension test (TST). After the behaviour tasks, biological samples were assessed to evaluate genotoxic and mutagenic effects using the comet assay and the micronucleus test. Garcinielliptone FC did not impair the performance of the animals in the rotarod and open‐field tests, with no antidepressant‐like effect in TST. No genotoxic effects in blood and cerebral cortex were observable in the comet assay; however, there was a significant increase in index and frequency of damage in liver after treatment with GFC 20 mg/kg. Garcinielliptone FC did not increase micronucleus frequency in bone marrow. At the tested doses, GFC was not toxic to the CNS and did not induce genotoxic damage to blood or bone narrow cells. DNA damage to liver tissue was caused only by the highest dose, although no mutagenic potential was observed.

Rosmarinic Acid Attenuates the Activation of Murine Microglial N9 Cells through the Downregulation of Inflammatory Cytokines and Cleaved Caspase-3

Objective: The present study evaluated the ability of rosmarinic acid (RA) to inhibit microglia activation induced by lipopolysaccharide (LPS) in the N9 murine microglial cell line, and investigated the putative mechanisms involved in this process. Methods: In all tests, N9 murine microglial cells were pretreated with RA (0.1, 1.0, and 10 μM) for 20 h and exposed to LPS (1 μM/mL) for 4 h. Cell viability was measured by Trypan blue exclusion assay. Flow cytometry was used to detect reactive oxygen species (ROS), quantify cleaved caspase-3, and analyze the mitochondrial electrochemical potential. iNOS, Arg-1, TNF-α, IL-1β, and IL-6 proteins were analyzed by Western blotting, and their antigens were detected using the chemiluminescence technique. The effect of RA on DNA was evaluated by the Comet assay. Results: RA attenuated the expression of the M1 marker iNOS and the levels of proinflammatory factors, including TNF-α, IL-1β, and IL-6; it increased the expression of the M2 marker Arg-1, and inhibited, at least in part, ROS generation and loss of mitochondrial outer membrane permeabilization through the inhibition of cleaved caspase-3 activation. RA also inhibited DNA damage, reassuring cell protection. Conclusions: The results suggested a protective effect of RA through downregulation of inflammatory cytokines and cleaved caspase-3.