Increase In TBARS Research Articles

Physiological responses of oxidative damage, genotoxicity and hematological parameters of the toxic effect of neonicotinoid-thiamethoxam in Oreochromis niloticus

The purpose of investigation assessed the impacts of neonicotinoid thiamethoxam (TMX) at sublethal concentrations in hematological profile and renal function of Oreochromis niloticus. In the experiment, fish were exposed to TMX in four groups (0, 50, 100 and 150 ppm) for 7 days. At the end of the experiment, biochemical analysis of blood samples showed that the parameters indicating renal function showed a significant increase in serum enzymes ALT, AST, ALP and metabolites (BUN, urea, uric acid, creatinine and cortisol) concentrations, while albumin concentration decreased in a dose-dependent manner compared to the control group. In parallel with the decrease in Na+, K+ and Ca+2 in blood ion levels, there was a significant decrease in the activity of Na+/K+ ATPase, Ca+2 ATPase and AChE enzyme, levels of GSH and HSP70 in kidney tissue in TMX groups compared to the control group. It was determined that the toxic effect of TMX caused a significant increase in TBARS, PC, 8-OHdG levels, respectively. In conclusion, our study shows that TMX causes dose-dependent toxic effects, with knock-on effects on physiological processes regarding the hematological profile and renal function of O. niloticus.

Modulation of blood redox status by the progression of induced apical periodontitis in rats.

This study aimed to investigate if apical periodontitis in different periods changes systemic levels of the antioxidant and pro-oxidant parameters in Wistar rats. Twenty-four rats were randomly allocated into healthy animals, apical periodontitis at 14days (AP14) and apical periodontitis at 28days (AP28). The first mandibular molars were accessed in the AP groups, and the pulp chamber was exposed to the oral environment, inducing the apical lesion. After 14 and 28days, the animals were anesthetized, euthanized, and hemimandibles were collected for micro-computed tomography (micro-CT) analysis to measure lesion volume, bone volume (BV), percent of bone to total tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular space (Tb.Sp). A histological examination of the remaining bone was also performed. Finally, blood samples were collected for oxidative biochemistry analysis, investigating glutathione (GSH), Trolox equivalent antioxidant capacity (TEAC), and lipid peroxidation (TBARS). The lesion volume was greater at 28 than at 14days, as shown by micro-CT. AP14 and AP28 had decreased BV and Tb.Th, but only AP28 showed a reduction in BV/TV. Tb.N and Tb. Sp were increased in apical periodontitis at 28 days. In the histopathological analysis, AP14 had focal regions of moderate mononuclear inflammatory infiltrate, and AP28 had an intense inflammatory infiltrate with bacterial colonies. In the biochemical evaluation, GSH, TEAC, and TBARS were increased after 14 days. However, GSH returned to control levels, TEAC was similar to AP14, and TBARS increased significantly after 28days. Therefore, the oxidative biochemistry response was modulated according to the progression of periapical damage. After 14days, the organism could still react to the injury. However, at 28days, the antioxidant response decreased, associated with an increase in TBARS.

Quality Assessment and Comparative Study of Value-added Giblet Pickle Incorporated with Red Calyces of Roselle (Hibiscus subdariffa) and Acetic Acid

Background: The present study was carried out to develop a suitable formulation for value added pickle out of chicken giblet by incorporating roselle and evaluate their physico-chemical properties, sensory attributes and shelf-life qualities through microbial count, extend of proteolysis and fat rancidity after packaging in normal food grade polyethylene packaging material stored at ambient temperature. Methods: The developed value added giblet pickle was standardised with 15% rosella. The comparison was made among the samples incorporated in paste, oven dried powdered and 4% acetic acid. Result: The addition of 15% roselle in paste form increased the overall acceptability as well as the product yield. The protein content of both the treatments was found to be higher compared to the control. The pH of control (3.06±0.04) ranged to 4.25±.07 in treatment. The water activity did not differ significantly in control and treatments and the value ranged from 0.94±0.12 to 0.95±0.04. Thiobarbituric acid value (TBARS), tyrosine values and microbial count significantly (p less than 0.05) increased during storage days in all the pickle samples. However, the increase in TBARS, tyrosine values and microbial load were within the recommended limits as per FSSAI for pickled meat products. From the above study, it can be conclude that value-added giblet pickle with good nutritive value and higher acceptability can be prepared by incorporating roselle at 15% level.

Microbiological, Physicochemical and Sensorial Changes during the Ripening of Sucuk, a Traditional Turkish Dry-Fermented Sausage: Effects of Autochthonous Strains, Sheep Tail Fat and Ripening Rate

This study aimed to investigate the effects of autochthonous starter cultures (spontaneous fermentation, Lactiplantibacillus plantarum GM77, Staphylococcus xylosus GM92 or L. plantarum GM77 + S. xylosus GM92) isolated from sucuk (a traditional Turkish dry fermented sausage), the use of sheep tail fat (beef fat-control, sheep tail fat and beef fat + sheep tail fat) and the ripening rate (slow or fast) on the microbiological, physicochemical and sensorial changes during the ripening of sucuk. L. plantarum GM77 as a monoculture or mixed culture with S. xylosus GM92 exhibited good growth during fermentation and following days of ripening. S. xylosus GM92 remained at the inoculation level of 106 CFU/g. L. plantarum GM77 as a monoculture inhibited the growth of spontaneous Micrococcus/Staphylococcus in both the slow and fast ripening conditions. In the presence of L. plantarum GM77, the pH value decreased under 5.0 after the first three days of fermentation. The fast ripening yielded a lower mean aw and TBARS values compared to the slow ripening. Regarding TBARS value, the lowest mean value was determined in the presence of L. plantarum GM77 + S. xylosus GM92. The use of sheep tail fat caused an increase in TBARS; the highest mean value was determined in sucuk prepared with only sheep tail fat. The groups with L. plantarum GM77 yielded a higher mean L* value, while the highest a* value was determined in the group with L. plantarum GM77 + S. xylosus GM92. In addition, fast ripening caused an increase in the a* value. The L*, a* and b* values were not affected by the use of sheep tail fat. L. plantarum GM77 + S. xylosus GM92 groups demonstrated the best results in terms of general acceptability in both slow and fast ripening.

Anti-Alzheimer, antioxidants, glucose-6-phosphate dehydrogenase effects of Taverniera glabra mediated ZnO and Fe2O3 nanoparticles in alloxan-induced diabetic rats

Abstract The current study aimed to assess the neuroprotective effect of Zn and Fe oxide nanoparticles biofabricated by Taverniera glabra in alloxan-induced diabetic rats. The experimental animals (160–200 g) were divided into nine groups (n = 9). The blood glucose, body weight, glucose-6-phosphate dehydrogenase (G6PD), superoxide dismutase (SOD), catalase test (CAT), lipid peroxidation (TBARS), glutathione (GSH), and acetylcholinesterase (AChE) activities were determined. Oral administration of nanoparticles and T. glabra methanol extract (TGME; 10 and 15 mg/kg b.w) significantly decreased the glucose level, increased the body weight, controlled the quantitative level of G6PD, and significantly decreased the levels of ALT, ALP, cholesterol, and creatinine. Moreover, TGME and their Zn and Fe oxide nanoparticles significantly restored the antioxidant enzymes (SOD, CAT, GPx, and GSH) that decreased during induced diabetes. In the diabetic group, a significant increase in TBARS was noted and recovered in diabetic animals (p < 0.05) as compared to glibenclamide. The AChE activity was significantly recovered by nanoparticles and TGME both in the blood and brain of the diabetic group (p < 0.05). Taken together, it can be suggested that TGME and Zn and Fe oxide nanoparticles significantly improved memory and could be considered as an effective biogenic nanomaterial for diabetes, Alzheimer’s disease, and oxidative stress.

Time dependent cisplatin dosing differences on hypoalgesia focusing on oxidative stress

Although cisplatin is a key drug in cancer chemotherapy, it often causes sensory peripheral neuropathy, presenting as allodynia in the early stage and hypoalgesia in the serious stage. Chronotherapy has previously been shown to ameliorate cisplatin-induced peripheral neuropathy that was severe enough to cause hypoalgesia in rats. It also has adverse effects such as renal dysfunction and ototoxicity, which are induced by oxidative stress. Here, we show that oxidative stress causes severe cisplatin-induced peripheral neuropathy, and that differences in oxidative stress occur depending on the dosing time of cisplatin.Cisplatin was administered to rats at 5:00 or 17:00 every seven days for four weeks. The antioxidant agent, 1,3-Dimethylthiourea (DMTU), was administered before and after the administration of cisplatin. The hot plate test was used to assess hypoalgesia. Oxidative stress in the sciatic nerve was assessed from thiobarbituric acid reactive substances (TBARs) and superoxide dismutase (SOD) activity. Nerve apoptosis was analysed with qRT-PCR.We observed an increase in TBARs and a decrease in SOD activity with the development of cisplatin-induced hypoalgesia, which was ameliorated by DMTU treatment. Furthermore, differences in the dosing time of cisplatin caused differences in oxidative stress which were correlated with cisplatin-induced hypoalgesia.Severe oxidative stress caused cisplatin-induced hypoalgesia, and chronotherapy with cisplatin ameliorated hypoalgesia by reducing oxidative stress. In the future, chronotherapy with cisplatin may contribute to the treatment of cancer in humans.

Physical and antioxidant properties of gelatine film added with sesame, rice bran, and coconut oil

Gelatine is commonly used as packaging in the food industry because it has the proper physical properties. The present work observed that there were no differences in moisture content and solubility of the packaging film after adding 4% of gelatine film with 0.5% of rice bran, sesame, and coconut oil. Meanwhile, water vapour permeability, tensile strength, and elongation of the gelatine films increased when added with the oil. The colour value depended on the colour of the oil added to the gelatine films. The colour value of the gelatine films added with sesame and coconut oil did not differ from the gelatine film without the addition of any oil. The addition of coconut oil to the gelatine film resulted in increased antioxidant activity. Wrapping chicken, pork, and beef with the gelatine films added with all three types of oil showed no differences in pH values for all three types of meat products throughout refrigeration storage for 12 days. Meat wrapped in gelatine film added with coconut oil showed an increase in TBARS, while TBARS were lower in the gelatine film without the addition of any oil or added with rice bran and sesame oil. This indicated that after coconut oil was added to the gelatine film, it decreased oxidation in the meat products during storage.

Silver nano/microparticle toxicity in the shrimp Litopenaeus vannamei (Boone, 1931)

The effects of silver nano/microparticles (AgP) on juvenile Litopenaeus vannamei shrimp were evaluated through several responses, aiming to use it as a prophylactic and therapeutic method. Shrimps (3.19 ± 0.13 g) were exposed to clear water for 3 h with increasing concentrations of nanosilver (0; 25; 100; and 400 μg/l). After 3 h of exposure, they were transferred to water without nanosilver for 30 days (recovery). The weight gain and weekly growth were not affected by AgNP. Total antioxidant capacity (ACAP) increased in the hepatopancreas (exposure period) and gills (recovery) in shrimp exposed to AgNP. In muscle, ACAP was induced in shrimp exposed to 100 μg/l AgNP (exposure). In the gills, there was an increase in TBARS in shrimp exposed to 100 μg/l AgNP (recovery). In the concentration of protein-associated sulfhydryl groups (P-SH), a decrease was observed in the hepatopancreas (recovery) in the 100 μg/l AgNP treatment. In chromaticity parameters, an increase in reddish tones was observed in shrimp exposed to 100 μg/l AgNP (recovery). An increase in granular hemocytes was verified in shrimp exposed to 25 and 400 μg/l AgNP during exposure. Tissues analyzed histologically showed normal patterns without apoptosis or necrosis processes, and after 30 d of recovery, only in one muscle sample of shrimp exposed to μg/l of AgNP was silver detected. It is concluded that a prophylactic action of short duration (3 h) mostly did not affected the welfare of shrimp L. vannamei and can be considered its use as a therapeutic strategy.

Anti-Alzheimer and Antioxidant Effects of Nelumbo nucifera L. Alkaloids, Nuciferine and Norcoclaurine in Alloxan-Induced Diabetic Albino Rats.

The present study is aimed to determine the efficacy and dose response of the nuciferine (1), norcoclaurine (2) and crude extract of Nelumbo nucifera in managements of diabetes, Alzheimer disease and related allergies. Experimentally, alloxan (100 mg/kg body weight (b.w.))-induced diabetic rats (200–250 g) were divided into seven groups (n = 6). Group I: normal control, Group II: diabetic control, Group III: standard treated with glibenclamide and Group lV-VII: treated with methanolic crude extracts (100, 200 mg/kg), nuciferine and norcoclaurine (10 mg/kg b.w.) for 15 days. Different tests were performed, including blood glucose, body weights and antioxidant enzyme assays, i.e., superoxide dismutase (SOD), catalase test (CAT), lipid peroxidation assay (TBARS), glutathione assay (GSH) and acetylcholinesterase (AChE) assay. Nuciferine and norcoclaurine significantly reduced blood glucose (p < 0.05) and restored body weight in diabetic rats. Moreover, nuciferine and norcoclaurine (10 mg/kg) significantly recovered the antioxidant enzymes (SOD, CAT, GPx and GSH) which decreased during induced diabetes. Significant increase in TBARS was also observed in the diabetic group and nuciferine as well as norcoclaurine (10 mg/kg) inhibited the increase in TBARS in diabetic animals (p < 0.05), as compared to glibenclamide. AChE activity was significantly recovered by nuciferine and norcoclaurine (10 mg/kg) both in the blood and brain of the diabetic group (p < 0.05). Nuciferine and norcoclaurine showed potent inhibitory effects against α-glucosidase and α-amylase with IC50, 19.06 ± 0.03, 15.03 ± 0.09 μM and 24.07 ± 0.05, 18.04 ± 0.021 μM, as confirmed by molecular docking studies. This study concludes that nuciferine and norcoclaurine significantly improve memory and could be considered as an effective phytomedicine for diabetes, Alzheimer’s disease (AD) and oxidative stress.

Oxidative Stress and DNA Damage in Peripheral Blood Mononuclear Cells from Normal, Obese, Prediabetic and Diabetic Persons Exposed to Thyroid Hormone In Vitro.

Diabetes, a chronic group of medical disorders characterized byhyperglycemia, has become a global pandemic. Some hormones may influence the course and outcome of diabetes, especially if they potentiate the formation of reactive oxygen species (ROS). There is a close relationship between thyroid disorders and diabetes. The main objective of this investigation was to find out whether peripheral blood mononuclear cells (PBMCs) are more prone to DNA damage by triiodothyronine (T3) (0.1, 1 and 10 μM) at various stages of progression through diabetes (obese, prediabetics, and type 2 diabetes mellitus—T2DM persons). In addition, some biochemical parameters of oxidative stress (catalase-CAT, thiobarbituric acid reactive substances—TBARS) and lactate dehydrogenase (LDH) were evaluated. PBMCs from prediabetic and diabetic patients exhibited increased sensitivity for T3 regarding elevated level of DNA damage, inhibition of catalase, and increase of TBARS and LDH. PBMCs from obese patients reacted in the same manner, except for DNA damage. The results of this study should contribute to a better understanding of the role of thyroid hormones in the progression of T2DM.

Synergistic Effect of Static Magnetic Field and Modified Atmosphere Packaging in Controlling Blown Pack Spoilage in Meatballs.

This study aimed to compare the microbial diversity in meatballs with or without blown pack spoilage (BPS) to determine the cause of BPS and to assess the synergistic effect of static magnetic field (SMF) and modified atmosphere packaging (MAP) to reduce the phenomenon of BPS. Results showed that the BPS group with a 2.26-fold larger volume and packaging containing 71.85% CO2 had Klebsiella spp. (46.05%) and Escherichia spp. (39.96%) as the dominant bacteria, which was different from the spoilage group. The results of isolation and identification of strains from the BPS group and their inoculation test confirmed that Klebsiella pneumoniae was the major strain-inducing BPS in meatballs due to its pack-swelling ability. SMF (5 mT) treatment combined with MAP (40%CO2 + 60%N2), which did not influence the sensory quality of meatballs, had a significant synergistic effect on preventing the increase in pack volume. Compared with the control group, this synergistic treatment effectively delayed bacterial growth, drop in pH, and the increase of TBARS. The findings of this study will provide further guidance for meatball manufacturers to adopt effective strategies to reduce the BPS of meatballs.

Physiological insights on soybean response to drought

As most of the soybean in Europe is grown in rainfed conditions, climate aberrations are causing significant crop yield variability. To stabilise the yield and shift the sources of supply to European-grown soybean, stable and adaptable cultivars must be created by breeding. To better understand the mechanism of drought tolerance in specific germplasm, more knowledge needs to be acquired by research. Therefore, this research aimed to examine the physiological insights on soybean response to drought exposed plants (50% available water holding capacity) by monitoring the relative water content (RWC), lipid peroxidation (TBARS), pigments (Chl a and b), proteins and photosynthetic efficiency during five days in the pod stage. The decrease of RWC in both tested genotypes due to the drought effect, coupled with TBARS increase, indicates lipid peroxidation, which resulted in photosynthetic pigment and protein changes. Most of the chlorophyll a fluorescence parameters suggested plants initiated a defence mechanism to water deficiency, i.e. there was an initial adjustment on the first and second day of drought exposed plants, followed by drastic changes in electron flow in photosystem II (PSII). According to the correlation analysis, the effect of drought was prevalent for Chl b, Chl a/b, relative variable fluorescence at 30 ms (VI), the density of reaction centres (RC/CS0), absorption, trapping, electron transport and dissipation flux per reaction centre (ABS/RC, TR0/RC, ET0/RC and DI0/RC), plastoquinone at quinone A binding niche reducing RCs per PSII antenna chlorophylls (RC/ABS) and performance index (PIABS), meaning these parameters are good indicators of drought stress, that can facilitate the selection of genotypes and increase the efficiency of breeding programmes. Among tested materials, Korana had lower sensitivity to drought and smaller reduction of yield components than OS-211, indicating a better response of its defence mechanism to oxidative stress caused by lack of water. The methods tested and confirmed in this research could be used for screening large numbers of genotypes to determine in the soybean breeding programs aiming to select superior genotypes adaptable to weather changes.

Increased bone resorption by long-term cigarette smoke exposure in animal model

IntroductionClinical and experimental studies have been attesting the deleterious effects of smoking mainly due to the stimulation of osteoclastogenesis and inhibition of osteoblastogenesis. However the physiological mechanisms that can explain these changes are not fully understood. AimsTo evaluate the trabecular bone resorption effect caused by long-term exposure to cigarette smoke and the action of cytokines and reactive oxygen species involved in this process. MethodsSixty young adult C57BL/6 mice were allocated to two groups: control, 30 animals exposed to filtered air for 1, 3 and 6 months; and smoke, 30 animals exposed to cigarette smoke for 1, 3 and 6 months. Femoral and tibial extraction was performed to evaluate the bone mineral matrix, bone cytokines (Receptor activator of nuclear factor-kappa B ligand - RANKL and Osteoprotegerin - OPG) and oxidative stress markers (Thiobarbituric acid reactive substances - Tbars). ResultsExposure to cigarette smoke (CS) generated changes in bone structural parameters in the 6th month of follow-up, demonstrating an evident bone loss; reduction in OPG/RANKL ratio from the 3rd month on and increase in Tbars in the first month, both closely related to the increase in osteoclastogenic activity and bone resorption. ConclusionThese findings reinforce the importance of CS-induced oxidative stress in bone compromising the bone cellular activities with a consequent impairment in bone turn over and changes in bone structure.

Combining ozone and slurry ice treatment to prolong the shelf-life and quality of large yellow croaker (Pseudosciaena crocea)

The effect of different ice treatments (flake ice (FI), slurry ice (SI) and ozonated slurry ice (OSI)) on the microorganism, physicochemical properties and shelf life of large yellow croaker (Pseudosciaena crocea) was evaluated during refrigerated storage. Microbiological and physicochemical analysis, low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) were measured at 3-days interval. The results showed that, compared with FI, SI could greatly inhibit the growth of microorganisms and slow down the increase of TBARS, TVB-N, K value and BAs, which had the ability to isolate oxygen and cover the fish completely with subzero temperature. While OSI could inhibit the increase of microbial number, K value and BAs dramatically, which were closely related to strong bacteriostatic ability of ozone. The results of LF-NMR and MRI revealed that the combined use of slurry ice and ozone could more efficiently retard the water migration, maintain the quality of fish. This experiment revealed that combined use of slurry ice and ozone represented a promising technique to maintain high safety and quality and extend the shelf-life of large yellow croaker.

Impact of frozen storage on oxidation changes of some components in goose meat

The objective of this study was to investigate the oxidation activity and lipid oxidation changes in breast (BM) and leg (LM) muscles from 17-wk-old female White Kołuda geese packaged in a vacuum, and stored in freezing conditions at −20°C. The geese were fed ad libitum during the experimental period (up to 17 wk) on the same complete feed. The samples of LM (n = 18) and BM (n = 18) from the right carcass were stored for 30, 90, 80, 270, and 365 d. Lipid oxidation was described by determining changes in: TBARS value expressing the amount of malondialdehyde (MDA), total antioxidant capacity (TAC) measured by DPPH and ABTS methods and total reduction potential (TRP) measured by FRAP method. Moreover, total heam pigments pigment (THP), relative concentration of myoglobin (Mb), oxymyoglobin (MbO2), and metmyoglobin (MMb) were determined in this study. Time of storage affected the TAC, TRP, TBARS, and the color stability of BM and LM. The THP concentration and Mb proportion decrease gradually during the 365 d of frozen storage, while the relative concentration of MMb increase in BM and LM. It was noted that the shares of MMb in both analyzed types of muscles stored for 365 d did not exceed 0.4. This value is considered to be the limit, after which the meat takes on an intense gray-brown color not accepted by the consumer. The oxidation processes occurring during frozen storage caused an increase of TBARS and a decrease of DPPH•, ABTS•+, FRAP values in both kinds of muscles. The amounts of TBARS during frozen storage of muscles did not exceed 2.0 mg MDA/kg of meat. A higher value of TBARS than 2.0 causes a lack of acceptance by consumers of the flavor profile. Based on the results concerning changes in the heam pigments, as well as changes related to the oxidation of lipids, we cannot unequivocally state in which types of muscles the changes had a more intense course.

Hemoglobin-mediated lipid oxidation of herring filleting co-products during ensilaging and its inhibition by pre-incubation in antioxidant solutions

The aims of this study were to investigate the role of hemoglobin (Hb) in lipid oxidation development during ensilaging of herring filleting co-products, and, to inhibit this reaction by pre-incubating the co-products in water or physiological salt, with/without different antioxidants. Results showed that both peroxide value (PV) and 2-thiobarbituric acid reactive substances (TBARS) gradually increased during 7 days of ensilaging at 22 °C in absence of antioxidants. The increase in TBARS was proportional to the Hb levels present, while PV was less affected. A Hb-fortified Tris-buffer model system adjusted to pH 3.50 confirmed that Hb changed immediately from its native oxyHb to the metHb state, which facilitated heme group release and thus probably explains the increased PV and TBARS during ensilaging. Pre-incubating the co-products for 30 s in a solution containing 0.5% rosemary extract was the most promising strategy to inhibit lipid oxidation both in the co-products during pre-processing storage and during the actual ensilaging. The solution could be re-used up to ten times without losing its activity, illustrating that this methodology can be a scalable and cost-effective strategy to extend the oxidative stability of herring co-products allowing for further value adding e.g., into a high-quality silage.

Hypolipidemic, hypoglycemiant and antioxidant effects of Myrcia splendens (Sw.) DC in an animal type 2 diabetes model induced by streptozotocin

We investigated the effects of dichloromethane extract (DME) from Myrcia splendens on alterations caused by type 2 diabetes in the blood and kidney of rats, in order to reduce side effects caused by synthetic drugs. Rats received streptozotocin (60 mg/kg), 15 minutes after nicotinamide (120 mg/kg) or water. After 72 hours, the glycemic levels were evaluated to confirm diabetes and the animals received (15 days) DME (25, 50, 100 or 150mg/Kg) or water. DME partially reversed hyperglycemia and (100 and 150 mg/kg) reversed hypertriglyceridemia. Histopathological findings elucidated that DME reduced damage to pancreatic islets. DME 150 mg/kg reversed the increases in TBA-RS, the reduction in the sulfhydryl content, 100 and 150 mg/kg increased CAT, reversed the decrease in GSH-Px and increased it activity in the blood. DME 150 mg/kg reversed CAT and GSH-Px reductions in the kidney. We believe that DME effects might be dependent on the presence of phenolic compounds.

Sex influences in the preventive effects of peripubertal supplementation with N-3 polyunsaturated fatty acids in mice exposed to the two-hit model of schizophrenia

Schizophrenia is a devastating neurodevelopmental disorder. The animal model based on perinatal immune activation, as first-hit, combined with peripubertal stress, as a second hit, has gained evidence in recent years. Omega-3 polyunsaturated fatty acids (n3-PUFAs) is being a promise for schizophrenia prevention. Nevertheless, the influence of sex in schizophrenia neurobiology and prevention has been neglected. Thus, the present study evaluates the preventive effects of n3-PUFAs in both sexes' mice submitted to the two-hit model and the participation of oxidative changes in this mechanism. The two-hit consisted of polyI:C administration from postnatal days (PNs) 5–7, and unpredictable stress from PNs35-43. n3-PUFAs were administered from PNs30-60. Prepulse inhibition of the startle reflex (PPI), social interaction, and Y-maze tests were conducted between PNs70-72 to evaluate positive-, negative-, and cognitive-like schizophrenia symptoms. We assessed brain oxidative changes in brain areas and plasma. Both sexes’ two-hit mice presented deficits in PPI, social interaction, and working memory that were prevented by n3-PUFAs. In two-hit females, n3-PUFAs prevented increments in nitrite levels in the prefrontal cortex (PFC), hippocampus, striatum, and plasma TBARS levels. In two-hit males, n3-PUFAs prevented the increase in TBARS in the PFC, hippocampus, and striatum. Notably, male mice that received only n3-PUFAs without hit exposure presented impairments in working memory and social interaction. These results add further preclinical evidence for n3-PUFAs as an accessible and effective alternative in preventing behavioral and oxidative changes related to schizophrenia but call attention to the need for precaution in this indication due to hit- and sex-sensitive issues.

Increased Bone Resorption by Long-Term Cigarette Smoke Exposure in Animal Model

Introduction: Clinical and experimental studies have been attesting the deleterious effects of smoking mainly due to the stimulation of osteoclastogenesis and inhibition of osteoblastogenesis. However the physiological mechanisms that can explain these changes are not fully understood. Aims: To evaluate the bone resorption effect caused by long-term exposure to cigarette smoke and the action of cytokines and reactive oxygen species involved in this process. Methods: Sixty young adult C57BL/6 mice were allocated to two groups: control, 30 animals exposed to filtered air for 1, 3 and 6 months; and smoke, 30 animals exposed to cigarette smoke for 1, 3 and 6 months. Femoral and tibial extraction was performed to evaluate the bone mineral matrix, bone cytokines (Receptor activator of nuclear factor-kappa B ligand - RANKL and Osteoprotegerin - OPG) and oxidative stress markers (Thiobarbituric acid reactive substances - Tbars). Results: Exposure to cigarette smoke (CS) generated changes in bone structural parameters in the 6th month of follow-up, demonstrating an evident bone loss; reduction in OPG/RANKL ratio from the 3rd month on and increase in Tbars in the first month, both closely related to the increase in osteoclastogenic activity and bone resorption. Conclusion: These findings reinforce the importance of CS-induced oxidative stress in bone compromising the bone cellular activities with a consequent impairment in bone turn over and changes in bone structure. Funding: None to declare. Declaration of Interests: None to declare. Ethics Approval Statement: This study was approved by the Review Board for human and animal studies from the University of Sao Paulo School of Medicine - Project Number 937/17

Oxidative damage, inflammation, genotoxic effect, and global DNA methylation caused by inhalation of formaldehyde and the purpose of melatonin.

Formaldehyde (FA) exposure has been proven to increase the risk of asthma and cancer. This study aimed to evaluate for 28days the FA inhalation effects on oxidative stress, inflammation process, genotoxicity, and global DNA methylation in mice as well as to investigate the potential protective effects of melatonin. For that, analyses were performed on lung, liver and kidney tissues, blood, and bone marrow. Bronchoalveolar lavage was used to measure inflammatory parameters. Lipid peroxidation (TBARS), protein carbonyl (PCO), non-protein thiols (NPSH), catalase activity (CAT), comet assay, micronuclei (MN), and global methylation were determined. The exposure to 5-ppm FA resulted in oxidative damage to the lung, presenting a significant increase in TBARS and NO levels and a decrease in NPSH levels, besides an increase in inflammatory cells recruited for bronchoalveolar lavage. Likewise, in the liver tissue, the exposure to 5-ppm FA increased TBARS and PCO levels and decreased NPSH levels. In addition, FA significantly induced DNA damage, evidenced by the increase of % tail moment and MN frequency. The pretreatment of mice exposed to FA applying melatonin improved inflammatory and oxidative damage in lung and liver tissues and attenuated MN formation in bone marrow cells. The pulmonary histological study reinforced the results observed in biochemical parameters, demonstrating the potential beneficial role of melatonin. Therefore, our results demonstrated that FA exposure with repeated doses might induce oxidative damage, inflammatory, and genotoxic effects, and melatonin minimized the toxic effects caused by FA inhalation in mice.