ß-Cyclodextrins alter the energy metabolism-related enzyme activities in rats.

Although widely used in medicine, separation technology, and other fields, the effects of cyclodextrins on the activities of phosphoryl transfer enzymes have not been previously evaluated. In vivo studies evaluated the function of cyclodextrins as active compounds. Despite the use of cyclodextrins as active compounds, the effects of cyclodextrins on hepatic and renal tissues remain to be fully elucidated. The primary objective of this study was to evaluate the effects of ß- cyclodextrins, methyl-ß-cyclodextrin (M-ß- cyclodextrins), and (2-hydroxypropyl)-ß-cyclodextrin (HP-ß-cyclodextrins) on enzyme activities regulating the maintenance of energy homeostasis in the kidney and liver tissues in relation to toxicity. Serum levels of liver and kidney markers were measured, and oxidative stress parameters were assessed. After 60-day treatments, we observed that the administration of ß-cyclodextrins and M-ß-cyclodextrins inhibited the hepatic activity of pyruvate kinase, an irreversible enzyme within the glycolytic pathway. Additionally, administration of HP-ß-cyclodextrins inhibited creatine kinase activity and increased the total sulfhydryl content in kidneys. Here, we demonstrated for the first time that ß-cyclodextrins, M-ß-cyclodextrins, and HP-ß-cyclodextrins cause bioenergetic dysfunction in renal and hepatic tissues. These findings suggest that understanding the balance between cyclodextrins' efficacy and adverse effects is essential for better accepting their use in medicine.

Resveratrol and resveratrol-hydroxypropyl-ß-cyclodextrin complex recovered the changes of creatine kinase and Na+, K+-ATPase activities found in the spleen from streptozotocin-induced diabetic rats.

Type 1 diabetes (T1D) is the result of the selective destruction of the pancreatic ß-cells by T cells of the immune system. Although spleen is a secondary lymphoid organ, it is also involved in the T1D pathogenesis. However, the alterations in a variety of cellular processes of this disease need to be further understood. We aimed to analyze the benefits of resveratrol, and its complexed form on diabetic complications in the spleen of rats. To this end, we investigated important enzymes of phosphoryl transfer network, and Na+, K+-ATPase activity. Wistar rats were divided into non-diabetic groups: Control, Ethanol, Resveratrol, Hydroxypropyl-ß-cyclodextrin, Resveratrol-hydroxypropyl-ß-cyclodextrin, and diabetic groups with the same treatments. Diabetes was induced by a single dose of 60 mg/kg of streptozocin intraperitoneally, and treatments by intragastric gavage once daily for 60 days. Hyperglycemia reduced creatine kinase activity, which was reversed by the administration of resveratrol. Na+, K+-ATPase activity was greatly affected, but it was reversed by resveratrol and resveratrol-hydroxypropyl-ß-cyclodextrin. This suggest an energetic imbalance in the spleen of diabetic rats, and in case this also occurs in the diabetic patients, it is possible that resveratrol supplementation could be beneficial to the better functioning of the spleen in diabetic patients.

PEGylated meloxicam-loaded nanocapsules reverse in vitro damage on caspase activity and do not induce toxicity in cultured human lymphocytes and mice.

Meloxicam is an anti-inflammatory drug that has a potential protective effect in many common diseases. However, this molecule is quickly eliminated from the body due to it short half-life. One way to overcome this problem is to incorporate meloxicam into lipid-core nanocapsules which may increase it anti-inflammatory effects. In view of this, the objective of this work was to evaluate the potential toxicity and safety of these novel nanomaterials both in vitro and in vivo. Here, we evaluated the effects of uncoated meloxicam-loaded nanocapsules (M-NC), uncoated and not loaded with meloxicam or blank (B-NC), PEGylated meloxicam-loaded lipid-core nanocapsules (M-NCPEG), blank PEGylated lipid-core nanocapsules (B-NCPEG) and free meloxicam (M-F) in vitro through the analysis of cell viability, caspase activity assays and gene expression of perforin and granzyme B. Meanwhile, the in vivo safety was assessed using C57BL/6 mice that received nanocapsules for seven days. Thus, no change in cell viability was observed after treatments. Furthermore, M-NC, M-NCPEG and M-F groups reversed the damage caused by H2O2 on caspase-1, 3 and 8 activities. Overall, in vivo results showed a safe profile of these nanocapsules including hematological, biochemical, histological and genotoxicity analysis. In conclusion, we observed that meloxicam nanocapsules present a safe profile to use in future studies with this experimental protocol and partially reverse in vitro damage caused by H2O2.

Production, characterization and toxicology assay of creatine pegylated nanoliposome with polysorbate 80 for brain delivery.

Creatine acts intracellularly as energy buffer and storage, demonstrating protective effects in animal models of neurodegenerative diseases. However, its permeability throught blood-brain barrier (BBB) is reduced. The aim of the present study was developing a carrier to facilitate the delivery of creatine to the central nervous system. Creatine nanoliposomes were produced, characterized and assayed in models of toxicity in vitro and in vivo. Particles showed negative zeta potential (-12,5 mV), polydispersity index 0.237 and medium-size of 105 nm, which was confirmed by transmission electron microscopy (TEM) images. Toxicity assay in vitro was evaluated with blank liposomes (no drug) or creatine nanoliposomes at concentrations of 0.02 and 0.2 mg/mL, that did not influence the viability of Vero cells. The result. of the comet assay that the nanoliposomes are not genotoxic, togeher with cell viability demonstrated that the nanoliposomes are not toxic. Besides, in vivo assays not demonstrate toxicity in hematological and biochemical markers of young rats. Nevertheless, increase content of creatine in the cerebral cortex tissue after subchronic treatment was observed. Altogether, results indicate increase permeability of creatine to the BBB that could be used as assay for in vivo studies to confirm improved effect than free creatine.

Thiol/disulfide status regulates the activity of thiol-containing kinases related to energy homeostasis in rat kidney

ABSTRACT Considering that thiol-containing enzymes like kinases are critical for several metabolic pathways and energy homeostasis, we investigated the effects of cystine dimethyl ester and/or cysteamine administration on kinases crucial for energy metabolism in the kidney of Wistar rats. Animals were injected twice a day with 1.6 µmol/g body weight cystine dimethyl ester and/or 0.26 µmol/g body weight cysteamine from the 16th to the 20th postpartum day and euthanized after 12 hours. Pyruvate kinase, adenylate kinase, creatine kinase activities and thiol/disulfide ratio were determined. Cystine dimethyl ester administration reduced thiol/disulfide ratio and inhibited the kinases activities. Cysteamine administration increased the thiol/disulfide ratio and co-administration with cystine dimethyl ester prevented the inhibition of the enzymes. Regression between the thiol/disulfide ratio, and the kinases activities were significant. These results suggest that redox status may regulate energy metabolism in the rat kidney. If thiol-containing enzymes inhibition and oxidative stress occur in patients with cystinosis, it is possible that lysosomal cystine depletion may not be the only beneficial effect of cysteamine administration, but also its antioxidant and thiol-protector effect.

Thiol/disulfide status regulates the activity of thiol-containing kinases related to energy homeostasis in rat kidney.

Considering that thiol-containing enzymes like kinases are critical for several metabolic pathways and energy homeostasis, we investigated the effects of cystine dimethyl ester and/or cysteamine administration on kinases crucial for energy metabolism in the kidney of Wistar rats. Animals were injected twice a day with 1.6 µmol/g body weight cystine dimethyl ester and/or 0.26 µmol/g body weight cysteamine from the 16th to the 20th postpartum day and euthanized after 12 hours. Pyruvate kinase, adenylate kinase, creatine kinase activities and thiol/disulfide ratio were determined. Cystine dimethyl ester administration reduced thiol/disulfide ratio and inhibited the kinases activities. Cysteamine administration increased the thiol/disulfide ratio and co-administration with cystine dimethyl ester prevented the inhibition of the enzymes. Regression between the thiol/disulfide ratio, and the kinases activities were significant. These results suggest that redox status may regulate energy metabolism in the rat kidney. If thiol-containing enzymes inhibition and oxidative stress occur in patients with cystinosis, it is possible that lysosomal cystine depletion may not be the only beneficial effect of cysteamine administration, but also its antioxidant and thiol-protector effect.

Amyloid-ß peptide absence in short term effects on kinase activity of energy metabolism in mice hippocampus and cerebral cortex.

Considering that Alzheimer's disease is a prevalent neurodegenerative disease worldwide, we investigated the activities of three key kinases: creatine kinase, pyruvate kinase and adenylate kinase in the hippocampus and cerebral cortex in Alzheimer's disease model. Male adult Swiss mice received amyloid-ß or saline. One day after, mice were treated with blank nanocapsules (17 ml/kg) or meloxicam-loaded nanocapsules (5 mg/kg) or free meloxicam (5 mg/kg). Treatments were performed on alternating days, until the end of the experimental protocol. In the fourteenth day, kinases activities were performed. Amyloid-ß did not change the kinases activity in the hippocampus and cerebral cortex of mice. However, free meloxicam decrease the creatine kinase activity in mitochondrial-rich fraction in the group induced by amyloid-ß, but for the cytosolic fraction, it has raised in the activity of pyruvate kinase activity in cerebral cortex. Further, meloxicam-loaded nanocapsules administration reduced adenylate kinase activity in the hippocampus of mice injected by amyloid-ß. In conclusion we observed absence in short-term effects in kinases activities of energy metabolism in mice hippocampus and cerebral cortex using amyloid-ß peptide model. These findings established the foundation to further study the kinases in phosphoryltransfer network changes observed in the brains of patients post-mortem with Alzheimer's disease.

Diphenyl diselenide supplementation in infected mice by Toxoplasma gondii: Protective effect on behavior, neuromodulation and oxidative stress caused by disease.

The aim of this study was to evaluate the effect of subcutaneous administration of diphenyl diselenide (PhSe)2 on animal behavior and activities of acetylcholinesterase (AChE), adenylate kinase (AK), and creatine kinase (CK) in the brain of mice infected by Toxoplasma gondii. In addition, thiobarbituric acid reactive species (TBARS) levels and glutathione (GR, GPx and GST) activity were also evaluated. For the study, 40 female mice were divided into four groups of 10 animals each: group A (uninfected and untreated), group B (uninfected and treated with (PhSe)2), group C (infected and untreated) and group D (infected and treated with (PhSe)2). The mice were inoculated with 50 cysts of the ME49 strain of T. gondii. After infection the animals of the groups B and D were treated on days 1 and 20 post-infection (PI) with 5.0 µmol/kg of (PhSe)2 subcutaneously. Behavioral tests were conducted on days 29 PI to assess memory loss (object recognition), anxiety (elevated plus maze), locomotor and exploratory activity (Open Field) and it was found out that infected and untreated animals (group C) had developed anxiety and memory impairment, and the (PhSe)2 treatment did not reverse these behavioral changes on infected animals treated with (PhSe)2 (group D). The results showed an increase on AChE activity (P < 0.01) in the brain of infected and untreated animals (group C) compared to the uninfected and untreated animals (group A). The AK and CK activities decreased in infected and untreated animals (group C) compared to the uninfected and untreated animals (group A) (P < 0.01), however the (PhSe)2 treatment did not reverse these alterations. Infected and untreated animals (group C) showed increased TBARS levels and GR activity, and decreased GPx and GST activities when compared to uninfected and untreated animals (group A). Infected animals treated with (PhSe)2 (group D) decreased TBARS levels and GR activity, while increased GST activity when compared to infected and untreated animals (group C). It was concluded that (PhSe)2 showed antioxidant activity, but the dose used had no anti-inflammatory effect and failed to reverse the behavioral changes caused by the parasite.

Synergistic effects of resveratrol (free and inclusion complex) and sulfamethoxazole-trimetropim treatment on pathology, oxidant/antioxidant status and behavior of mice infected with Toxoplasma gondii.

This study aimed to investigate the synergistic effects of resveratrol and sulfamethoxazole-trimethoprim (ST) on the treatment of mice experimentally infected by Toxoplasma gondii during the chronic phase of the disease considering infection, behavior, and oxidative/antioxidants profile aspects. For the study, 60 mice were initially divided into two groups: uninfected (n = 24) and infected by T. gondii (n = 36). These two groups were later subdivided into other groups and treated with resveratrol (free and inclusion complex containing resveratrol) alone and co-administered with ST: groups A to D were composed by healthy mice and groups E to J were consisted of animals infected by T. gondii (VEG strain). Treatments began 20 days post-infection for 10 consecutive days with oral doses of 0.5 mg kg(-1) of ST (groups B and F), 100 mg kg(-1) of free resveratrol (groups C and G) and inclusion complex of resveratrol (nanoparticles containing resveratrol) (groups D and H), and lastly an co-administration of both drugs (groups I and J). Behavioral tests (memory, anxiety and locomotion) were performed after treatment. Liver and brain fragments were collected to evaluate pathological changes, brain cysts counts, as well as oxidant and antioxidant levels. A reduction on the number of cysts in the brain of animals treated with both drugs combined was observed; there was also reduced number of lesions on both organs. This drug combined effect was also able to reduce oxidative and increase antioxidant levels in infected mice, which might be interpreted as a resveratrol protective effect. In addition, the combination of ST and resveratrol was able to prevent behavioral changes in infected mice. Therefore, the use of co-administration drugs enhances the therapeutic effect acting on a synergic way, reducing the oxidizing effects of the chemical treatment for toxoplasmosis. In addition, resveratrol in inclusion complex when co-administered with ST showed an improved therapeutic effect of ST reducing oxidative damage, liver damage and the number of cysts in the brain of T. gondii infected mice.

Toxoplasma gondii: Effects of diphenyl diselenide in experimental toxoplasmosis on biomarkers of cardiac function.

This study aimed to investigate the effects of diphenyl diselenide (PhSe)2 to treat mice experimentally infected by Toxoplasma gondii on seric biomarkers of cardiac function (creatine kinase, creatine kinase MB, troponin, and myoglobin), and lactate dehydrogenase, as well as to evaluate the enzymatic activity of creatine kinase (CK) and adenylate kinase (AK) in heart tissue. For the study, 40 female mice were divided into four groups of 10 animals each: the group A (uninfected and untreated), the group B (uninfected and treated), the group C (infected and untreated) and the group D (infected and treated). The inoculation was performed with 50 cysts of T. gondii (ME-49 strain). Mice from groups B and D were treated at days 1 and 20 post-infection (PI) with 5 µmol kg(-1) of (PhSe)2 subcutaneously. On day 30 PI, the mice were anesthetized and euthanized for blood and heart collection. As a result, it was observed a decrease in AK activity (P < 0.01) in the heart samples of groups C and D compared to the group A. Cardiac CK increased in the group C compared to the group A (P < 0.01). CK levels increased in infected mice (the group C) compared to other groups (A and D). Regarding CK-MB level, there was a decrease in the group D compared to the group B, without statistical difference compared to control groups (A and C). It was observed an increase on myoglobin in groups C and D, differently of troponin, which did not show statistical difference (P < 0.05) between groups. Mice from the group C showed an increase in lactate dehydrogenase (LDH) levels compared to other groups (A, B, and D). Histopathological evaluation of heart samples revealed necrosis, hemorrhagic regions and inflammatory infiltrates in mice from the Group C, differently from the group D where animals showed only inflammatory infiltrates. Based on these results we conclude that the (PhSe)2 had a protective effect on the heart in experimental toxoplasmosis by modulating tissue and seric CK activity, and avoiding an increase on seric LDH levels, probably due to the antioxidant effect of this compound.

Meloxicam-loaded nanocapsules as an alternative to improve memory decline in an Alzheimer's disease model in mice: involvement of Na(+), K(+)-ATPase.

The objective of this study was to investigate the effect of meloxicam-loaded nanocapsules (M-NC) on the treatment of the memory impairment induced by amyloid ß-peptide (aß) in mice. The involvement of Na(+), K(+)-ATPase and cyclooxygenase-2 (COX-2) activities in the hippocampus and cerebral cortex was also evaluated. Mice received aß (3 nmol/ 3 µl/ per site, intracerebroventricular) or vehicle (3 µl/ per site, i.c.v.). The next day, the animals were treated with blank nanocapsules (17 mL/kg) or M-NC (5 mg/kg) or free meloxicam (M-F) (5 mg/kg). Treatments were performed every other day, until the twelfth day. Animals were submitted to the behavioral tasks (open-field, object recognition, Y-maze and step-down inhibitory avoidance tasks) from the twelfth day. Na(+), K(+)-ATPase and COX-2 activities were performed in hippocampus and cerebral cortex. aß caused a memory deficit, an inhibition of the hippocampal Na(+), K(+)-ATPase activity and an increase in the hippocampal COX-2 activity. M-NC were effective against all behavioral and biochemical alterations, while M-F restored only the COX-2 activity. In conclusion, M-NC were able to reverse the memory impairment induced by aß, and Na(+), K(+)-ATPase is involved in the effect of M-NC.

Blood gas analyses and other components involved in the acid-base metabolism of rats infected by Trypanosoma evansi.

The aim of this study was to investigate the effects of Trypanosoma evansi infections on arterial blood gases of experimentally infected rats. Two groups with eight animals each were used; group A (uninfected) and group B (infected). Infected animals were daily monitored through blood smears that showed high parasitemia with 30 trypanosomes per field (1000×) on average, 5 days post-infection (PI). Arterial blood was collected at 5 days PI for blood gas analysis using an automated method based on dry-chemistry. Hydrogen potential (pH), partial oxygen pressure (pO2), oxygen saturation (sO2), sodium (Na), ionic calcium (Ca ionic), chlorides (Cl), partial dioxide carbon pressure (pCO2), base excess (BE), base excess in the extracellular fluid (BEecf), bicarbonate (cHCO3), potassium (K), lactate, and blood total dioxide the carbon (tCO2) were evaluated. The levels of pH, pCO2, BE, BEecf, cHCO3, and tCO2 were significantly decreased (P < 0.05) in group B compared to group A. Additionally, the same group showed increases in Cl and lactate levels when compared to uninfected group. Therefore, it is possible to state that the infection caused by T. evansi led to alterations in the acid-base status, findings that are correlated to metabolic acidosis.

Activity of cholinesterases, pyruvate kinase and adenosine deaminase in rats experimentally infected by Fasciola hepatica: Influences of these enzymes on inflammatory response and pathological findings.

The aim of this study was to investigate acetylcholinesterase (AChE) in total blood and liver tissue; butyrylcholinesterase (BChE) in serum and liver tissue; adenosine deaminase (ADA) in serum and liver tissue; and pyruvate kinase (PK) in liver tissue of rats experimentally infected by Fasciola hepatica. Animals were divided into two groups with 12 animals each, as follows: group A (uninfected) and group B (infected). Samples were collected at 20 (A1 and B1;n=6 each) and 150 (A2 and B2; n=6 each) days post-infection (PI). Infected animals showed an increase in AChE activity in whole blood and a decrease in AChE activity in liver homogenates (P<0.05) at 20 and 150 days PI. BChE and PK activities were decreased (P<0.05) in serum and liver homogenates of infected animals at 150 days PI. ADA activity was decreased in serum at 20 and 150 days PI, while in liver homogenates it was only decreased at 150 days PI (P<0.05). Aspartate aminotransferase and alanine aminotransferase activities in serum were increased (P<0.05), while concentrations of total protein and albumin were decreased (P<0.05) when compared to control. The histological analysis revealed fibrous perihepatitis and necrosis. Therefore, we conclude that the liver fluke is associated with cholinergic and purinergic dysfunctions, which in turn may influence the pathogenesis of the disease.

Relationship between pathological findings and enzymes of the energy metabolism in liver of rats infected by Trypanosoma evansi.

The aim of this study was to investigate the activities of important enzymes involved in the energetic metabolism in the liver of rats experimentally infected by Trypanosoma evansi. Adenylate kinase (AK), pyruvate kinase (PK), and lactate dehydrogenase (LDH) in liver homogenate, as well as aspartate aminotransferase (AST), alanine aminotransferase (ALT), and clotting time in plasma were evaluated at 5 and 15 days post-infection (PI). The activities of the respiratory chain complexes and of Na(+), K(+)-ATPase were also evaluated. This study demonstrates energetic metabolism impairment in rats infected by T. evansi. A reduced energy metabolism in the liver of rats infected by T. evansi was observed, demonstrated by AK decreased and PK increased activities at 5 days PI, a mechanism known as energetic compensation. However, at 15 days PI a decrease of AK and PK activities were observed. In addition, an increase in the activities of respiratory chain complexes II, II-III and IV in infected rats at 15 days PI, and a decrease of Na(+), K(+)-ATPase activities in infected rats on days 5 and 15 PI were verified. In the plasma, we observed an increase in ALT and AST activities on days 5 and 15 PI, and increase in clotting time in infected rats. The changes caused by T. evansi infection on the activity of enzymes of hepatic energy metabolism can corroborate to elucidate the mechanisms that lead to liver injury and inflammatory infiltration verified in T. evansi infected rats. Therefore, these alterations are directly related to disease pathogenesis.

Effects of sulfamethoxazole-trimethoprim associated to resveratrol on its free form and complexed with 2-hydroxypropyl-ß-cyclodextrin on cytokines levels of mice infected by Toxoplasma gondii.

The aim of this study was to investigate the effects of resveratrol on its free form and complexed with 2-hydroxypropyl-ß-cyclodextrin (HPßCD) when associated with sulfamethoxazole-trimethoprim (ST) on cytokines levels of mice (n = 60) experimentally infected by Toxoplasma gondii. Groups A and E were used as controls (untreated): negative and positive, respectively. The onset of treatment started 20 days post-infection (PI), and it lasted for 10 consecutive days. ST was administered orally in doses of 0.5 mg kg(-1) for groups B and F, while 100 mg kg(-1) was the dose for resveratrol in its free form (groups C - G), inclusion complex (groups D and H), and on free and inclusion complex together (groups I - J). On day 31 PI, blood samples were collected in order to evaluate the cytokine profile. The mice that received drug combination (I and J) showed a significant (P < 0.05) reduction in the number of cysts in the brain compared to other infected groups (E - H). The results showed that mice from the Group E had increased (P < 0.001) levels of pro-inflammatory cytokines, while IL-10 levels were reduced when compared to the Group A. Additionally, there were increased levels of IL-4 and IFN-γ in animals of groups C and D, respectively (P < 0.05). Animals of the Group B showed reduced levels of IL-1, IL-4, IL-6, TNF-α, and IFN-γ (P < 0.05). Mice infected and treated (groups F - J) showed increased levels of pro-inflammatory cytokines along with a reduction of IL-10. Treatment with the combination of drugs (the Group J) led to a protective effect, i.e. reduction in pro-inflammatory cytokines. Therefore, resveratrol associated with ST was able to modulate seric cytokine profile and moderate the tissue inflammatory process caused by T. gondii infection, as well as to reduce parasite multiplication.

Enzymatic activities linked to cardiac energy metabolism of Trypanosoma evansi-infected rats and their possible functional correlations to disease pathogenesis.

The aim of this study was to investigate the activities of important enzymes involved in the phosphoryl transfer network (adenylate kinase and creatine kinase (CK)), lactate dehydrogenase (LDH), respiratory chain complexes and biomarkers of cardiac function in rat experimentally infected by Trypanosoma evansi. Rat heart samples were evaluated at 5 and 15 days post-infection (PI). At 5 day PI, there was an increase in LDH and CK activities, and a decrease in respiratory chain complexes II, IV and succinate dehydrogenase activities. In addition, on day 15 PI, a decrease in the respiratory chain complex IV activity was observed. Biomarkers of cardiac function were higher in infected animals on days 5 and 15 PI. Considering the importance of the energy metabolism for heart function, it is possible that the changes in the enzymatic activities involved in the cardiac phosphotransfer network and the decrease in respiratory chain might be involved partially in the role of biomarkers of cardiac function of T. evansi-infected rats.

Relationship between behavioral alterations and activities of adenylate kinase and creatine kinase in brain of rats infected by Trypanosoma evansi.

The aim of this study was to investigate the behavioral assessment and activities of important enzymes involved in the phosphoryl transfer network in rat brains that were experimentally infected with Trypanosoma evansi. Behavioral assessment (cognitive performance), pro-inflammatory cytokines in serum and activities of adenylate kinase (AK), pyruvate kinase (PK), and creatine kinase (CK) in brain were evaluated at 5 and 15 days post-infection (PI). Here we demonstrate a cognitive impairment in the rats infected with T. evansi. At 5 and 15 days PI, a memory deficit and a depressant activity were demonstrated by an inhibition avoidance test and increase in the immobility time in a tail suspension test, respectively. On day 5 PI, a decrease in the CK activity and an increase in the AK activity were observed. On day 15 PI, an increase in the CK activity and a decrease in the AK activity were observed. Considering the importance of energy metabolism for brain functioning, it is possible that the changes in the activity of enzymes involved in the cerebral phosphotransfer network and an increase in the proinflammatory cytokines (TNF and IFN) may be involved at least in part in the cognitive impairment in infected rats with T. evansi.

Sulfamethoxazole-trimethoprim associated with resveratrol for the treatment of toxoplasmosis in mice: Influence on the activity of enzymes involved in brain neurotransmission.

This study aimed to investigate the influence of sulfamethoxazole-trimethoprim (ST) associated with resveratrol on the enzymatic activities of acetylcholinesterase (AChE), adenylate kinase (AK), pyruvate kinase (PK), and creatine kinase (CK) in the brain of mice experimentally infected by Toxoplasma gondii. For that, 60 mice were divided into ten groups with 6 animals each: groups A to D composed by healthy mice and groups E to J consisting of animals infected by T. gondii (VEG strain). Animals started treatment 20 days post-infection for 10 consecutive days with oral doses of 0.5 mg kg(-1) of ST (groups B and F), 100 mg kg(-1) of free resveratrol (groups C and G) and inclusion complex of resveratrol (nanoparticles containing resveratrol) (groups D and H), as well as with an association of both drugs (groups I and J). The results showed increased (P < 0.001) AChE activity on infected animals (groups E-J) when compared to not-infected (A) animals, and also uninfected animals treated with ST (group B) had increased AChE activity. AK activity decreased (P < 0.001) in the infected and untreated (group E), differently from the other groups that did not differ. PK activity did not differ between groups (P > 0.05). When comparing control groups (uninfected (A) and infected (E)), we verified a significant (P < 0.001) increase in CK activity in the brain, and it is noteworthy that the animals treated with resveratrol associated with ST (group I and J) had similar CK activity to those animals from the group A. Treatment with the combination of ST and resveratrol was able to reduce (P < 0.05) the number of parasitic cysts in the brain, thus reduced inflammatory infiltrates in the liver, and prevented the occurrence of hepatocytes lesions due to toxoplasmosis in mice. Based on these results, it is possible to conclude that increased AChE and CK activities after T. gondii infection did not change with the treatment of ST-resveratrol association. In addition, decreased AK activity caused by T. gondii infection was normalized by ST-resveratrol treatment. T. gondii infection and treatment does not affect PK activity in brain.

Treatment with essential oil of Achyrocline satureioides in rats infected with Trypanosoma evansi: relationship between protective effect and tissue damage.

The aim of this study was to evaluate the effects of treatment with free and nanoencapsulated essential oil of Achyrocline satureioides on trypanosomosis and its oxidative/antioxidants variables in liver and kidney of rats infected experimentally with Trypanosoma evansi. For that, 48 rats were divided into six groups (A-F), eight animals each group. Groups A, C and D were composed of uninfected animals, while animals in groups B, E and F were inoculated intraperitoneally with T. evansi. Groups A and B were used as controls, negative and positive, respectively. Groups C and E receive oil (orally), as well as the animals in groups D and F were treated with nanoencapsulated essential oil. The treatment was not able to eliminate the parasites, but it remained the levels of parasitemia low. The carbonyl levels in liver and kidney did not differ between groups. Infected animals (group B) showed an increase in the TBARS levels and a decrease in the CAT activity and NPSH levels in liver and kidney, compared with the same parameters in the control (group A). Treatment with A. satureioides (groups C and D) did not influence the TBARS levels and CAT activity in the liver, but it increased the CAT activity in kidneys of the animals of group C. NPSH levels decreased in liver in the groups treated with nanoencapsulated essential oil (groups D and F). An interesting result observed was that the animals infected and then treated with essential oil of A. satureioides (groups E and F) did not differ from animals of group A for TBARS, CAT and NPSH, unlike what happened with the animals of group B. Therefore, the treatment with essential oil did not eliminate the parasites from the bloodstream, but it reduced the number of trypanosomes, mainly by its nanoencapsulated form. The same occurred with the lipid peroxidation in the liver. However, the treatments reduced the oxidative damage, and it led to the activation of the antioxidant enzymes. We believe that the association of this natural product with a trypanocidal drug may enhance its curative effect.

Trypanocidal activity of the essential oils in their conventional and nanoemulsion forms: in vitro tests.

The aim of this study was to investigate the susceptibility in vitro of Trypanosoma evansi to the essential oils of andiroba (Carapa guaianensis) and aroeira (Schinus molle), in their conventional and nanostructured forms. For that, pure oils at concentrations of 0.5%, 1.0% and 2.0% were used. A negative control (untreated) and a positive control (diminazene aceturate 0.5%) were used as comparative parameters. Later, the same tests were performed, using nanoemulsions oils at concentrations of 0.5% and 1.0%. The tests were carried out in triplicates and the numbers of parasites were quantified on 1, 3 and 6 h from onset of the study. A dose-dependent reduction in the number of parasites to the forms of two oils tested was observed after 1 h. The concentration of parasites was significantly reduced at low concentrations after 3 h, as well as at 6 h no alive parasites were observed for the essential oils tested. Ours findings indicate, for the first time, that oils of andiroba and aroeira (in their conventional and nanoemulsion forms) have high activity against T. evansi in vitro, leading to the suggestion that these oils may be applied as an alternative treatment for this disease.