Hydrogel Containing Silibinin-Loaded Pomegranate Oil-Based Nanocapsules for Cutaneous Application: In Vitro Safety Investigation and Human Skin Biometry and Permeation Studies.

In previous studies, we developed a hydrogel formulation containing silibinin-loaded pomegranate oil nanocapsules (HG-NCSB) that had improved in vivo anti-inflammatory action in comparison to non-encapsulated silibinin. To determine skin safety and whether the nanoencapsulation influences silibinin skin permeation, NCSB skin cytotoxicity, HG-NCSB permeation in human skin, and a biometric study with healthy volunteers were conducted. The formulation of nanocapsules was prepared by the preformed polymer method while the HG-NCSB was obtained by thickening the suspension of nanocarriers with gellan gum. The cytotoxicity and phototoxicity of nanocapsules were assessed in Keratinocytes (HaCaT) and fibroblast (HFF-1) using the MTT assay. The hydrogels were characterized regarding the rheological, occlusive, and bioadhesive properties, and silibinin permeation profile in human skin. The clinical safety of HG-NCSB was determined by cutaneous biometry in healthy human volunteers. NCSB yielded better cytotoxicity results than the blank nanocapsules (NCPO). NCSB did not cause photocytotoxicity, while NCPO and the non-encapsulated substances (SB and pomegranate oil) were phototoxic. The semisolids presented non-Newtonian pseudoplastic flow, adequate bioadhesiveness, and low occlusive potential. The skin permeation demonstrated that HG-NCSB retained a higher SB amount in the outermost layers than HG-SB. In addition, HG-SB reached the receptor medium and had a superior concentration of SB in the dermis layer. In the biometry assay, there was no significant cutaneous alteration after the administration of any of the HGs. Nanoencapsulation promoted greater SB retention in the skin, averted percutaneous absorption, and made the topical use of SB and pomegranate oil safer.

Hesperozygis ringens (Benth.) Epling: a study involving extraction, chemical profiling, antioxidant and biological activity.

Hesperozygis ringens is a plant of the Lamiaceae family which is restricted to the Southern region of Brazil. It is popularly used as an insecticide, but knowledge on it is very scarce. This study aimed to determine the chemical markers of H. ringens extracts obtained via ultrasound-assisted (UAE-EtOH) and supercritical fluid (SFE-CO2) extractions. UAE-EtOH and SFE-CO2 extracts were characterised by UPLC-MS and GC-MS, respectively. Both products had their antioxidant activity, cytotoxicity and genotoxicity evaluated. Twelve compounds were found in the UAE-EtOH extract, including phenolic acids and flavonoids; the SFE-CO2 extract contained terpenes and phytosterols. The UAE-EtOH extract showed a greater antioxidant activity. Neither extract presented cytotoxicity or genotoxicity against human mononuclear blood cells.

Chemical study, antioxidant activity, and genotoxicity and cytotoxicity evaluation of Ruellia angustiflora.

Ruellia angustiflora (Acanthaceae) is known as flower-of-fire, and its leaves are traditionally employed to promote wound healing. This study was aimed at extracting and characterizing the chemical constituents of the extracts of R. angustiflora obtained by ultrasound-assisted and supercritical fluid extractions, and subsequently investigate their antioxidant potential and cyto-genotoxicity. The extract obtained by ultrasound (UAE-EtOH) was characterized by ultraperformance liquid chromatography-mass spectrometer (UPLC-MS), and the extract obtained via supercritical fluid (SFE-CO2) by gas chromatograph-mass spectrometer (GC-MS). The antioxidant potential was verified by the antiradical activity against the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), and the cyto-genotoxicity evaluation to test cell viability and DNA damage was performed in peripheral blood mononuclear cells (PBMC) cultures. The SFE-CO2 extract presented some fatty acids, triterpenes, tetraterpenes, tocopherols and phytosterols. The UAE-EtOH extract contained phenolic acids and flavonoids, and showed the highest antioxidant capacity. Neither extract was genotoxic or cytotoxic at the tested concentrations.

Topical hydrogel containing Achyrocline satureioides oily extract (free and nanocapsule) has anti-inflammatory effects and thereby minimizes irritant contact dermatitis.

Inflammatory dermatoses are prevalent worldwide, with impacts on the quality of life of patients and their families. The aim of this study was to determine the anti-inflammatory effects of Achyrocline satureioides oily extracts and nanocapsules on the skin using a mouse model of irritant contact dermatitis induced by croton oil, and a skin inflammation model induced by ultraviolet B (UVB) radiation. The mice were treated with 15 mg/ear oily extract (HG-OLAS) or nanocapsules (HG-NCAS) of A. satureioides incorporated into Carbopol® 940 hydrogels. We found that HG-OLAS and HG-NCAS formulations reduced ear edema in croton oil-induced lesions with maximum inhibitions of 54±7% and 74±3%, respectively. HG-OLAS and HG-NCAS formulations decreased ear edema induced by UVB radiation (0.5 J/cm2), with maximum inhibitions of 68±6% and 76±2% compared to the UVB radiation group, respectively. HG-OLAS and HG-NCAS modulated myeloperoxidase (MPO) activity after croton oil induction. Furthermore, croton oil and UVB radiation for 6 and 24 h, respectively, stimulated polymorphonuclear cells infiltration. The topical treatments reduced inflammatory processes, as shown by histological analysis. Together, the data suggest that topical application of A. satureioides oily extracts and nanocapsules produced antiedematogenic and anti-inflammatory effects. They constitute a compelling alternative for treatment of skin injuries.

Nanoencapsulation of the flavonoid dihydromyricetin protects against the genotoxicity and cytotoxicity induced by cationic nanocapsules.

We evaluated the influence of nanoencapsulation of the flavonoid Dihydromyricetin (DMY) in reducing the genotoxicity and cytotoxicity induced by cationic nanocapsules. Assays were conducted in order to evaluate the potential of protein corona formation, cytotoxicity, genotoxicity and the antioxidant capacity. Nanocapsules containing DMY (NC-DMY) and free DMY (DMY-F) did not demonstrate cytotoxicity and genotoxicity. However, Eudragit RS100® nanocapsules (NC-E) increased cytotoxicity and DNA damage formation. NC-DMY and NC-E presented high interaction with the DNA in vitro, suggesting DNA sequestration. These results indicate that nanoencapsulated DMY does not induce cytotoxicity or genotoxicity, and demonstrates high antioxidant capacity. This antioxidant capacity is probably associated with DMY, and occurs due to its ability to avoid the formation of free radicals, thus preventing the toxicity caused by the nanostructure with the cationic polymer Eudragit RS100®. Therefore, NC-DMY can be considered an important formulation with significant antioxidant potential to be exploited by nanomedicine.

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.

Protective effect of nerolidol-loaded in nanospheres against cerebral damage caused by Trypanosoma evansi.

Trypanosoma evansi is a zoonotic parasite associated with high animal mortality that has gained importance due to its capacity to infect humans. Recently, some evidences have demonstrated that T. evansi infection causes severe genotoxic and cytotoxic damage in brain cells, contributing to the pathogenesis and clinical signs of the disease. In this sense, the aim of this study was to evaluate whether nerolidol-loaded in nanospheres, a natural compound with trypanocidal and neuroprotective effects, is able to protect the brain tissue from the cytotoxic and genotoxic effects found during T. evansi infections. Trypanosoma evansi induced brain genotoxic effects through increased damage index (DI) and frequency of damage (FD) when compared to the control group. Moreover, T. evansi induced cytotoxic effects through the reduction of brain cell viability compared to the control group. The metabolites of nitric oxide (NO x ) increased in infected animals compared to the control group. The treatment with nerolidol-loaded in nanospheres prevented the increase on brain DI, FD, and NO x levels, as well as the reduction on cell viability. Based on these evidences, these results confirm that T. evansi induces genotoxic and cytotoxic damage mediated by the upregulation of NO x levels. The most important finding is that nerolidol-loaded in nanospheres was able to prevent DNA damage and cell mortality through the modulation of brain NO x levels. In summary, this treatment can be considered an interesting approach to prevent T. evansi brain damage due its anti-inflammatory property.

Treatment with tucumã oil (Astrocaryum vulgare) for diabetic mice prevents changes in seric enzymes of the purinergic system: Improvement of immune system.

The aim of this study was to evaluate the enzymatic activity of the purinergic system in sera samples from alloxan-induced diabetic mice treated with tucumã oil (Astrocaryum vulgare). For this, the mice were divided into four groups (n=6): control/water (the group CW); control/tucumã oil (the group CT); diabetic/water (the group DW), and diabetic/tucumã oil (the group DT) treated for 14days with 5.0mLkg-1 via oral gavage. On day 14 post-treatment, mice were submitted to euthanasia and blood samples were collected by cardiac puncture. Tucumã oil treatment significantly decreased (p<0.05) blood glucose levels in the group DT compared to the group DW. These results demonstrated an increase (p<0.05) in NTPDase (adenosine triphosphate (ATP substrate) or adenosine diphosphate (ADP substrate)), 5'-nucleotidase (AMP substrate) and adenosine deaminase (ADA; adenosine substrate) activities in serum from the group DW compared to the group CW. Tucumã oil treatment prevented these alterations in the group DT compared to the group DW, and restored these parameters near to the group CW. In summary, the treatment with tucumã oil was able to modulate the alterations caused by hyperglycemia probably by the presence of carotenoids compounds, maintaining normal levels of ATP, ADP, AMP and adenosine, molecules that could exhibit anti-inflammatory properties, depending on their concentration. Thus, the tucumã oil is a promising natural compound with protective action against diabetes and its side effects, such as changes in the purinergic system, improving the immune system.

Avian antibodies (IgY) against Trypanosoma cruzi: Purification and characterization studies.

Trypanosoma cruzi is a flagellated protozoan belonging to the Trypanosomatidae family, the etiologic agent of Chagas disease. Currently, there is neither a licensed vaccine nor effective treatment, characterizing an unmet clinical need. The IgY refers to the egg yolk immunoglobulin (Y=yolk) and its production and use are subjects of many studies due to the diversity of its diagnostic and therapeutic applications. Several researchers have shown that the use of specific IgY may prevent and/or control infectious and parasitic diseases. Based on these evidences, the aim of this study was to immunize chickens with trypomastigotes of T. cruzi in order to produce highly effective and pure antibodies (IgY), as well as extract, characterize, quantify, and verify cytotoxic effects of IgY anti-T. cruzi. After the induction of IgY production by chickens, the eggs were collected and the IgY was extracted by method of precipitation of polyethylene glycol 6000. The IgY anti-T. cruzi characterization was performed using polyacrylamide gel electrophoresis (SDS-PAGE), western-blot and enzyme-linked immunosorbent assay (ELISA). Moreover, the cytotoxic or proliferative effects of IgY anti-T. cruzi was verified by MTT assay. The concentration of IgY in yolk was 8.41±1.47mg/mL. The characterization of IgY reveled bands of stained peptides with molecular weight between 75 and 50kDa and 37 and 25kDa. In the ELISA test was observed that there was antigen-antibody reaction throughout the sample period. The concentrations of 1, 5 and 10mg/mL of IgY anti-T. cruzi presented no cytotoxic of proliferative effects in mononuclear and VERO cells in vitro. The results indicated that T. cruzi is able to generate a high production of specific immunoglobulins in chickens, it did not cause damage to the cell membrane and no proliferative effect.

Nanoencapsulation Improves Scavenging Capacity and Decreases Cytotoxicity of Silibinin and Pomegranate Oil Association.

Silibinin (SB) and pomegranate oil (PO) present therapeutic potential due to antioxidant activity, but the biological performance of both bioactives is limited by their low aqueous solubility. To overcome this issue, the aim of the present investigation was to develop nanocapsule suspensions with PO as oil core for SB encapsulation, as well as assess their toxicity in vitro and radical scavenging activity. The nanocapsule suspensions were prepared by interfacial deposition of preformed polymer method. SB-loaded PO-based nanocapsules (SBNC) showed an average diameter of 157 ± 3 nm, homogenous size distribution, zeta potential of -14.1 ± 1.7 mV, pH of 5.6 ± 0.4 and SB content close to 100%. Similar results were obtained for the unloaded formulation (PONC). The nanocapsules controlled SB release at least 10 times as compared with free SB in methanolic solution. The SBNC scavenging capacity in vitro was statistically higher than free SB (p < 0.05). Cell viability in monocytes and lymphocytes was kept around 100% in the treatments with SBNC and PONC, while the SB and the PO caused a decrease around 30% at 50 µM (SB) and 724 µg/mL (PO). Protein carbonyls and DNA damage were minimized by SB and PO nanoencapsulation. Lipid peroxidation occurred in nanocapsule treatments regardless of the SB presence, which may be attributed to PO acting as substrate in reaction. The free compounds also caused lipid peroxidation. The results show that SBNC and PONC presented adequate physicochemical characteristics and low toxicity against human blood cells. Thereby, this novel nanocarrier may be a promising formulation for therapeutic applications.

The use of tucumã oil (Astrocaryum vulgare) in alloxan-induced diabetic mice: effects on behavior, oxidant/antioxidant status, and enzymes involved in brain neurotransmission.

The aim of this study was to investigate the effects of tucumã oil (Astrocaryum vulgare) on memory, enzymatic activities of sodium-potassium pump (Na+, K+-ATPase) and acetylcholinesterase (AChE) in the brain of alloxan-induced diabetic mice. The animals were divided into four groups (n = 6 each): the group A (non-diabetic/water), the group B (non-diabetic/tucumã oil), the group C (diabetic/water), and the group D (diabetic/tucumã oil) treated 14 days with 5.0 mL kg-1 via oral gavage. Untreated diabetic mice (the group C) showed memory deficit, increased levels of thiobarbituric acid reactive species (TBARS) and protein carbonylation (PC), and decreased (p < 0.05) catalase (CAT), superoxide dismutase (SOD), and the Na+, K+-ATPase activities, while acetylcholinesterase (AChE) activity showed a significant increase (p < 0.05) compared to non-diabetic mice (the group A). Tucumã oil prevented these alterations in diabetic mice treated with tucumã oil (the group D) compared to diabetic mice (the group C). Our findings suggest that tucumã oil can modulate cholinergic neurotransmission resting membrane potential of neurons by modulating enzymatic antioxidant defenses. In conclusion, the present data showed that treatment with tucumã oil is beneficial to diabetic mice, demonstrating that this oil can modulate cholinergic neurotransmission and consequently improve or avoid memory deficits.

Antihyperglycemic, antioxidant activities of tucumã oil (Astrocaryum vulgare) in alloxan-induced diabetic mice, and identification of fatty acid profile by gas chromatograph: New natural source to treat hyperglycemia.

The aim of the study was to investigate the effect of the oral administration of tucumã oil (Astrocaryum vulgare) on glucose and insulin levels, oxidative status, and pancreatic genotoxic parameters of alloxan-induced diabetic mice. The animals were divided into four groups (n = 6 each): control/water; control/tucumã oil; diabetic/water; diabetic/tucumã oil treated for 14 days with 5.0 mL kg-1 via oral gavage. Gas chromatograph characterization demonstrated that oleic/elaidic fatty acid is the most abundant component present in this oil, followed by palmitic and stearic fatty acids. Our results demonstrated an increase (p < 0.05) in water and food intake, blood glucose, thiobarbituric acid reactive species (TBARS) levels, damage index, and frequency of damage; conversely body weight, insulin levels, catalase (CAT) and superoxide dismutase (SOD) activities, and cell viability were decreased in the diabetic/water group compared to the control/water group. The treatment with tucumã oil prevented these alterations in the diabetic/tucumã oil group compared to the diabetic/water group, and restored these parameters near to the control/water group. In summary, our findings demonstrated that treatment with tucumã oil causes a hypoglycemic effect improving insulin levels and antioxidant/oxidant status, and has a protector effect against pancreatic damage induced by oxidative stress in alloxan-induced diabetic mice.

Trypanocidal activity of the compounds present in Aniba canelilla oil against Trypanosoma evansi and its effects on viability of lymphocytes.

Aniba canelilla (H.B.K.) Mez, popularly known as "casca-preciosa" (precious bark), is a plant of the Lauraceae family, widely distributed in the Amazon region. Its major constituent is 1-nitro-2-phenylethane, a rare molecule in plants which is responsible for this plant's cinnamon scent. The present study aimed to report the chemical characterization of the oil extracted from Aniba canelilla using gas-chromatography/mass spectrometry and to assess its in vitro trypanocidal activity against Trypanosoma evansi, a prevalent haemoflagellate parasite that affects a broad range of mammal species in Africa, Asia and South America. The oil presented 1-nitro-2-phenylethane (83.68%) and methyleugenol (14.83%) as the two major components. The essential oil as well as both major compounds were shown to exert trypanocidal effect. Methyleugenol was slightly more active than 1-nitro-2-phenylethane. In vitro studies showed that the oil extracted from the stems of A. canelilla may be regarded as a potential natural treatment for trypanosomosis, once proven their in vivo action, may be an interesting alternative in the treatment of infected animals with T. evansi.

Achyrocline satureioides essential oil-loaded in nanocapsules reduces cytotoxic damage in liver of rats infected by Trypanosoma evansi.

The aim of this study was to evaluate whether the treatment with Achyrocline satureioides essential oil-loaded in nanocapsules (AS-NC) is able to protect the hepatic tissue against cytotoxic damage caused by Trypanosoma evansi. Thus, the rats were divided into four groups (n = 6 per group): uninfected/saline, uninfected/AS-NC, infected/saline, and infected/AS-NC. At day 4 post-infection (PI), the animals were euthanized and liver and sera samples were collected to perform the hepatic cell viability assay, and to determine seric levels of reactive oxygen species (ROS) and nitric oxide metabolites (NOx). Cell viability decreased (p < 0.05) in the infected/saline group compared to uninfected/saline group, while the treatment with AS-NC avoided this alteration in infected rats. Seric ROS and NOx levels increased (p < 0.05) in the infected/saline group compared to uninfected/saline group, while the treatment with AS-NC avoided this effect on ROS levels of infected rats. In summary, the treatment with AS-NC was able to protect the liver tissue against the cytotoxic effect caused by the parasite by avoiding exacerbated production of ROS.

Antibacterial, cyto and genotoxic activities of A22 compound ((S-3, 4 -dichlorobenzyl) isothiourea hydrochloride).

The A22 is a chemical compound that acts as a reversible inhibitor of a bacterial cell wall protein MreB leading the rods to the coccoid form. Thus, by changing the bacterial form, many properties can be affected, as the acquisition of nutrients, cell division, the clamping surfaces, motility and pathogenesis. Infections caused by strains of Pseudomonas aeruginosa have great clinical importance because these microorganisms can include more than one resistance mechanism acting together, limiting treatment options. Thus, it is important to investigate the action of A22 against P. aeruginosa, once there are urgent needs for new antimicrobial compounds for increase the arsenal therapeutic to treat diseases caused by this microrganism. Therefore, this study investigated for the first time the antimicrobial activity of A22 against seve standards strains of Gram negative microorganisms and twenty-eight clinical isolates of P. aeruginosa. This study performed an additional investigation to analyze the cyto and genotoxic potential effects from A22 on human peripheral blood mononuclear cells (PBMCs). The antibacterial activity of A22 was studied by broth microdilution method and time-kill assay. The cytotoxicity was evaluated by MTT assay at 24, 48 and 72 h of exposure to A22 and the genotoxicity was evaluated by the Comet assay. The susceptibility tests showed A22 has a relevant antibacterial activity against P. aeruginosa, including multidrug-resistant (MDR) clinical isolates. The A22 treatment not showed genotoxic effects against PBMCs in almost all concentrations tested at 24 and 48 h of exposure. Only for concentration of 32 µg/mL (highest tested) the damage index was significantly higher in all moments. The MTT assay demonstrated that A22 was able to maintain cell viability in all exposure times. In summary, the A22 demonstrated important anti-Pseudomonas activity and showed no cyto and genotoxic significant effect. These results need to be considered in future in vitro and in vivo studies in order to introduce the A22 as a possible therapeutic option.

Memory deficit, toxic effects and activity of Na(+), K(+)-ATPase and NTPDase in brain of Wistar rats submitted to orally treatment with alpha-terpinene.

The neurotoxic effects and activity of Na(+), K(+)-ATPase and NTPDase in Wistar rats after treatment with α-terpinene (daily oral administration of 0.5, 0.75 and 1.0mLkg(-1) for 10days) were examined. Results of the inhibitory avoidance task showed a memory deficit (p<0.05) in rats treated with all doses of α-terpinene. The evaluation of DNA damage in brain tissue revealed an increase (p<0.05) on frequency of damage and damage index in all concentrations. According to the cytotoxicity assay, doses of 0.5, 0.75 and 1.0mLkg(-1) increase the lactate dehydrogenase levels, and doses of 1.0mLkg(-1) also decrease (p<0.05) cell viability in brain cells. A decrease (p<0.05) on Na(+), K(+)-ATPase activity in brain tissue and on NTPDase activity in serum were observed in all concentrations of α-terpinene. These results suggest that the α-terpinene was cytotoxic and genotoxic to the brain cells by inducing loss of cell viability and DNA damage, as well as causing alterations in Na(+), K(+)-ATPase and NTPDase activity, what may contribute to the memory deficit of treated animals. Thus, α-terpinene cannot be consumed by the population at the doses studied.

Nerolidol nanospheres increases its trypanocidal efficacy against Trypanosoma evansi: New approach against diminazene aceturate resistance and toxicity.

The aims of this study were to develop nerolidol-loaded nanospheres, and to evaluate their efficacy in vitro and in vivo against Trypanosoma evansi, as well as to determine their physicochemical properties, morphology, and any possible side effect in vitro against peripheral blood mononuclear cell (PBMC). The nanospheres showed an adequate particle size (149.5 nm), narrow particle distribution (0.117), negative zeta potential (-12.8 mV), and pH of 6.84, such as observed by transmission electron microscopy. In vitro, a trypanocidal effect of nerolidol and nanospheres containing nerolidol was observed at 0.5, 1.0, and 2.0%, i.e., both treatments showed a faster trypanocidal effect compared to chemotherapy (diminazene aceturate - D.A.). T. evansi infected mice were used to evaluate the effects of nerolidol-loaded nanospheres regarding pre-patent period, longevity, and therapeutic efficacy. Oral administration of nerolidol-loaded nanospheres at 1.0 mL/kg/day during 10 days increased mice survival (66.66%) compared to 0% and 33.33% of mice survival when treated with nerolidol in its free form and D.A., respectively. Cytotoxic study indicated that both treatments showed no side effects in vitro against PBMC, an important marker used in toxicological surveys. Therefore, nanoencapsulation increased the therapeutic efficacy of nerolidol against T. evansi, and can be used as an alternative treatment for T. evansi infection.

Effects of treatment with the anti-parasitic drug diminazene aceturate on antioxidant enzymes in rat liver and kidney.

Diminazene aceturate (DA) is the active component of some trypanocidal drugs used for the treatment of animals infected with trypanosomosis and babesiosis. Residues of DA may cause hepatotoxic and nephrotoxic effects. Therefore, the purpose of this study was to investigate the occurrence of oxidative stress, i.e., changes in the antioxidant defense system of rats treated with a single dose of 3.5 mg kg(-1) of DA. All treatments were intramuscularly administered, and evaluations were performed on days 7 and 21 post-treatment (PT). Liver and kidney samples were collected and evaluated by histopathology and oxidative stress parameters (thiobarbituric acid-reactive species, catalase, superoxide dismutase, carbonyl, non-protein thiols, and reduced glutathione). Finally, blood was collected to determine seric DA concentration. Superoxide dismutase (SOD) and catalase (CAT) activities in liver and kidney of rats were dramatically inhibited (p < 0.05) compared to the control group on day 21 PT. This difference is related to the concomitant increase (p < 0.05) in malondialdehyde (MDA) content, which was identified by an increase in thiobarbituric acid-reactive species (TBARS) levels. The carbonyl levels did not differ between groups (p > 0.05). Both non-protein thiols (NPSH) and glutathione (GSH) levels in liver and kidney decreased (p < 0.05) on day 21 PT. Chromatographic analyses showed lower levels of DA on day 21 PT compared to day 7 PT. A negative correlation was observed between DA concentration in serum and lipid peroxidation in liver and kidney tissues on 21 days PT. Histopathology revealed vacuolar degeneration in liver and kidney samples on day 21 PT. Our findings indicate that DA could cause oxidative damage to liver and kidney of rats.

Relationship between DNA damage in liver, heart, spleen and total blood cells and disease pathogenesis of infected rats by Trypanosoma evansi.

Trypanosoma evansi is an important pathogen that causes changes in nitric oxide (NO) levels and antioxidant enzymes, as well as oxidative stress. The present study evaluated the in vivo effect of T. evansi infection on frequency and index of DNA damage in liver, heart, spleen and total blood of rats. Twenty rats were assigned into two groups with ten rats each, being subdivided into four subgroups (A1 and A2, 5 animals/group; and B1 and B2, 5 animals/group). Rats in the subgroups A1 and A2 were used as control (uninfected) and animals in the subgroups B1 and B2 were inoculated with T. evansi (infected). NO in serum and the comet assay were used to measure DNA damage index (DI) and damage frequency (DF) in liver, heart, spleen and total blood of infected rats. Increased NO levels on days 3 and 9 post-infection (PI) was observed (P < 0.001). Also, it was verified an increase on DI and DF in the evaluated organs on days 3 and 9 PI (P < 0.001). Our data show that T. evansi infection causes genotoxicity due to the production of NO, causing not only the death of the protozoan, but also inducing DNA damage in the host.

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.