Detection of SARS-CoV-2 virus using an alternative molecular method and evaluation of biochemical, hematological, inflammatory, and oxidative stress in healthcare professionals

In early December 2019, an outbreak of coronavirus disease 2019 caused by a new strain of coronavirus (SARS-CoV-2), occurred in the city of Wuhan, Hubei Province, China. On January 30, 2020, the World Health Organization (WHO) declared the outbreak a public health emergency of international concern. Since then, frontline healthcare professionals have been experiencing extremely stressful situations and damage to their physical and mental health. These adverse conditions cause stress and biochemical, hematological, and inflammatory changes, as well as oxidative damage, and could be potentially detrimental to the health of the individual. The study population consisted of frontline health professionals working in BHU in a city in southern Brazil. Among the 45 participants, two were infected with the SARS-CoV-2 virus and were diagnosed using immunochromatographic tests such as salivary RT-LAMP and qRT-PCR. We also evaluated biochemical, hematological, inflammatory, and oxidative stress markers in the participants. The infected professionals (CoV-2-Prof) showed a significant increase in the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholesterol, lactic dehydrogenase, lymphocytes, and monocytes. In this group, the levels of uric acid, triglycerides, leukocytes, neutrophils, hemoglobin, hematocrit, and platelets decreased. In the group of uninfected professionals (NoCoV-2-Prof), significant increase in HDL levels and the percentages of eosinophils and monocytes, was observed. Further, in this group, uric acid, LDH, triglyceride, and cholesterol levels, and the hematocrit count and mean corpuscular volume were significantly reduced. Both groups showed significant inflammatory activity with changes in the levels of C-reactive protein and mucoprotein. The NoCoV-2-Prof group showed significantly elevated plasma cortisol levels. To our kowledge, this study is the first to report the use of the RT-LAMP method with the saliva samples of health professionals, to evalute of SARS-CoV-2.

Water and suspended sediment runoff from vineyard watersheds affecting the behavior and physiology of zebrafish

Viticulture plays an important role in generating income for small farms globally. Historically, vineyards use large quantities of phytosanitary products, such as Bordeaux mixture [Ca(OH)₂ + CuSO₄], to control plant diseases. These products result in the accumulation of copper (Cu) in the soil and increases the risk of transfer to water bodies. Thus, it is important to evaluate whether the presence of Cu-bearing particles in water is toxic to aquatic fauna. This study conducted chemical, mineralogical, and particle size evaluations on water samples and sediments collected from a watershed predominantly cultivated with old vineyards. The proportion of Cu-rich nanoparticles (<10 nm) in the sediment was ~27%. We exposed zebrafish to different dilutions of water and sediment samples that collected directly from the study site (downstream river) under laboratory conditions. Then, we evaluated their exploratory behavior and the stress-related endocrine parameter, whole-body cortisol. We also carried out two experiments in which zebrafish were exposed to Cu. First, we determined the median lethal concentration (LC_{50-96 h}) of Cu and then assessed whether Cu exposure results in effects similar to those associated with exposure to the water and sediment samples collected from the study site. The water and sediment samples directly impacted the exploratory behavior of zebrafish, showing clear anxiety-like behavioral phenotype and stress in terms of cortisol increase (during the second rain event). The Cu exposure did not mimic the same behavioral changes triggered by the water and sediment samples, although it had caused similar stress in the fish. Our results highlight that even at low concentrations, the water and sediment samples from vineyard watershed runoff were able to induce behavioral and endocrine changes that may harm the ecological balance of an aquatic environment.

Bioprospection of novel synthetic monocurcuminoids: Antioxidant, antimicrobial, and in vitro cytotoxic activities

The irrational use of medications has increased the incidence of microbial infections, which are a major threat to public health. Moreover, conventional therapeutic strategies are starting to become ineffective to treat these infections. Hence, there is a need to develop and characterize novel antimicrobial compounds. Phytochemicals are emerging as a safe and accessible alternative to conventional therapeutics for treating infectious diseases. Curcumin is extracted from the dried rhizome of the spice turmeric (Curcuma longa (Zingiberaceae)). However, the bioavailability of curcumin is low owing to its lipophilic property and thus has a low therapeutic efficacy in the host. A previous study synthesized structural variants of curcumin, which are called monocurcuminoids (CNs). CNs are synthesized based on the chemical structure of curcumin with only one methyl bridge. The biological activities of four previously synthesized CNs (CN59, CN63, CN67, and CN77), curcumin, and turmeric powder were examined in this study. Gas chromatography-tandem mass spectrometry analysis of curcumin and turmeric powder revealed similar peaks, which indicated the presence of curcumin in turmeric powder. The antioxidant activity of the test compounds was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays. The ABTS radical scavenging activities of the test compounds were similar to those of vitamin C. The minimum inhibitory concentration (MIC) values of the test compounds against seven microbial strains were in the range of 4.06-150 μg/mL. The MIC value was equal to minimum bactericidal concentration value for CN63 (150 μg/mL) and CN67 (120 μg/mL) against Staphylococcus aureus. The treatment combination of CN77 (8.75 or 4.37 μg/mL) and turmeric powder (9.37 or 4.68 μg/mL) exerted synergistic growth-inhibiting effects on Aeromonas hydrophila, Candida albicans, and Pseudomonas aeruginosa. Photodynamic therapy using 2X MIC of CN59 decreased the growth of Enterococcus faecalis by 4.18-fold compared to the control group and completely inhibited the growth of Escherichia coli. The results of the hemolytic assay revealed that the test compounds were not cytotoxic with half-maximal inhibitory concentration values ranging from 49.65-130.9 μM. The anticoagulant activity of most compounds was comparable to that of warfarin but higher than that of heparin. This indicated that these compounds target the intrinsic coagulation pathway. These results demonstrated that these CNs are a safe and promising alternative for curcumin.

Ibuprofen during gestation prevents some changes in physical and reflex development in offspring in a model of hyperleucinemia and maternal inflammation

Maple Syrup Urine Disease (MSUD) is caused by a severe deficiency in the branched-chain ketoacid dehydrogenase complex activity. Patients MSUD accumulate the branched-chain amino acids leucine (Leu), isoleucine, valine in blood, and other tissues. Leu and/or their branched-chain α-keto acids are linked to neurological damage in MSUD. When immediately diagnosed and treated, patients develop normally. Inflammation in MSUD can elicit a metabolic decompensation crisis. There are few cases of pregnancy in MSUD women, and little is known about the effect of maternal hyperleucinemia on the neurodevelopment of their babies. During pregnancy, some intercurrences like maternal infection or inflammation may affect fetal development and are linked to neurologic diseases. Lipopolysaccharide is widely accepted as a model of maternal inflammation. We analyzed the effects of maternal hyperleucinemia and inflammation and the possible positive impact the use of ibuprofen in Wistar rats on a battery of physics (ear unfolding, hair growing, incisors eruption, eye-opening, and auditive channel opening) and neurological reflexes (palmar grasp, surface righting, negative geotaxis, air-righting, and auditory-startle response) maturation parameters in the offspring. Maternal hyperleucinemia and inflammation delayed some physical parameters and neurological reflexes, indicating that both situations may be harmful to fetuses, and ibuprofen reversed some settings.

In vitro and in silico protein corona formation evaluation of curcumin and capsaicin loaded-solid lipid nanoparticles

Nanotechnology has been an important tool for the production of nanoparticles with controlled release of drugs for therapeutic applications. Here, we produced solid lipid nanoparticles (SLN) loaded with curcumin and capsaicin (NCC) following the overarching goals of green chemistry. Currently, besides evaluating the composition, and size of these, it is necessary to understand the interactions between nanoparticles and the biomolecules present in the biological medium. For this, assays were conducted in order to evaluate the potential formation of the protein 'corona', and to better understand the results obtained in vitro, we also performed an interaction study, in silico, between the NCC components and the main serum protein, albumin. In the first hour of contact between the NCC and the culture medium showed fluctuation in the diameter of the NCC. However, after 24 and 48 h of the incubation period, all NCC concentrations showed an increase in size, which can be attributed to plasma protein adsorption. Since, hard corona takes a few seconds, while the soft corona can be formed in minutes up to a few hours. On the other hand, best docking binding-poses of interaction for the formed docking complexes evaluated suggest interactions following the docking affinity like free energy FEB (Tween 80-bovine serum albumin) ≈ FEB (Span 80-bovine serum albumin) showing a pharmacodynamic pattern based in non-covalent hydrophobic interactions with the bovine serum albumin binding-site. Our in silico results clarify and reinforce our in vitro findings of corona formation, which represents the real interaction with cell membranes in vivo.

Effect of the treatment with Achyrocline satureioides (free and nanocapsules essential oil) and diminazene aceturate on hematological and biochemical parameters in rats infected by Trypanosoma evansi

This study aimed to verify the effect of the treatment with A. satureioides essential oil (free and nanoencapsulated forms) and diminazene aceturate on hematological and biochemical variables in rats infected by Trypanosoma evansi. The 56 rats were divided into seven groups with eight rats each. Groups A, C and D were composed by uninfected animals, and groups B, E, F and G were formed by infected rats with T. evansi. Rats from groups A and B were used as negative and positive control, respectively. Rats from the groups C and E were treated with A. satureioides essential oil, and groups D and F were treated with A. satureioides nanoencapsulated essential oil. Groups C, D, E and F received one dose of oil (1.5 mL kg(-1)) during five consecutive days orally. Group G was treated with diminazene aceturate (D.A.) in therapeutic dose (3.5 mg kg(-1)) in an only dose. The blood samples were collected on day 5 PI for analyses of hematological (erythrocytes and leukocytes count, hemoglobin concentration, hematocrit, mean corpuscular and mean corpuscular hemoglobin concentration) and biochemical (glucose, triglycerides, cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin, urea and creatinine) variables. A. satureioides administered was able to maintain low parasitemia, mainly the nanoencapsulated form, on 5 days post infection. On the infected animals with T. evansi treated with A. satureioides essential oil (free and nanocapsules) the number of total leucocytes, lymphocytes and monocytes present was similar to uninfected rats, and different from infected and not-treated animals (leukocytosis). Treatment with A. satureioides in free form elevated levels of ALT and AST, demonstrating liver damage; however, treatment with nanoencapsulated form did not cause elevation of these enzymes. Finally, treatments inhibited the increase in creatinine levels caused by infection for T. evansi. In summary, the nanoencapsulated form showed better activity on the trypanosome; it did not cause liver toxicity and prevented renal damage.

Cysteamine prevents inhibition of thiol-containing enzymes caused by cystine or cystine dimethylester loading in rat brain cortex

Cystinosis is a systemic genetic disease caused by a lysosomal transport deficiency accumulating cystine in the lysosomes of all tissues. Although tissue damage might depend on cystine accumulation, the mechanisms of tissue damage are still obscures. Considering that thiol-containing enzymes are critical for several metabolic pathways, our main objective was to investigate the effects of cystine or cystine dimethylester load on the thiol-containing enzymes creatine kinase and pyruvate kinase, in the brain cortex of young Wistar rats. The animals were injected twice a day with 1.6 micromol/g body weight of cystine dimethylester or 1 micromol/g body weight of cystine and/or 0.46 micromol/g body weight of cysteamine from the 16th to the 20th postpartum day and sacrificed after 12 h. Cystine or cystine dimethylester administration inhibited the two enzyme activities. Co-administration of cysteamine, the drug used to treat cystinotic patients, normalized the two enzyme activities. Lactate dehydrogenase activity, a nonthiol-containing enzyme was not affected by cystine dimethylester administration. Cystine inhibits creatine kinase and pyruvate activities possibly by oxidation of the sulfhydryl groups of the enzymes. Considering that creatine kinase and pyruvate kinase, like other thiol-containing enzymes, are crucial for energy homeostasis and antioxidant defenses, the enzymes inhibition caused by cystine released from lysosomes could be one of the mechanisms of tissue damage in patients with cystinosis.

Effects of cysteamine on oxidative status in cerebral cortex of rats

Cystinosis is a systemic genetic disease caused by a lysosomal transport deficiency accumulating cystine in most tissues. Tissue damage depends on cystine accumulation, but the mechanisms of this damage are still obscure. Cysteamine administration depletes cystine accumulated, increasing survive of affected patients. Studies performed in fibroblasts of cystinotic patients suggest that apoptosis is enhanced in this disease. Considering that oxidative stress is a known apoptosis inducer, our main objective was to investigate a possible antioxidant effect of cysteamine on several parameters of oxidative stress in the brain of young rats. Animals received three subcutaneous injections at 3-h intervals of a buffered solution (pH 7.4) of 10 mg/kg body weight cysteamine and were sacrificed 1 h after the last injection. Cysteamine decreased lipoperoxidation and glutathione peroxidase activity, and increased the carbonyl content of proteins and catalase activity. In vitro studies showed that cysteamine reduced lipoperoxidation, 2',7'-dihydrodichlorofluorescein oxidation, carbonyl content of proteins and catalase activity, and increased glutathione peroxidase activity. These results suggest that cysteamine may act as a scavenger of superoxide free radicals and hydrogen peroxide. Therefore, it is possible that cysteamine may extend life of cystinotic patients acting not only as a cystine depleting drug, but also as a free radical scavenger, reducing cell damage by apoptosis.

Cystine Inhibits Creatine Kinase Activity in Pig Retina

BACKGROUND

Cystinosis is an autosomal recessive disorder associated with lysosomal cystine accumulation caused by defective cystine efflux. Visual deficit is a possible consequence of cystine accumulation in cornea and retina. Fibroblasts from cystinotic patients present ATP deficit with intact mitochondrial energy-generating capacity by an unknown mechanism. Considering that creatine kinase is a thiol enzyme crucial for energy homeostasis in retina, and disulfides like cystine may alter thiol enzymes, the main objective of the present study was to investigate the effect of cystine and cysteamine, the drug used for treatment of cystinotic patients, on creatine kinase activity in cytosolic and mitochondrial fractions of the retina from adult pigs.

METHODS

Retina was isolated from 6-month-old Landrace pigs, homogenized and mitochondrial and cytosolic fractions separated by centrifugation. Cytosolic and mitochondrial creatine kinase activities were determined in the presence of different concentrations of cystine and/or cysteamine.

RESULTS

Cystine inhibited the enzyme activity in a dose- and time-dependent manner and cysteamine prevented and reversed the inhibition caused by cystine, suggesting that cystine inhibits creatine kinase activity by oxidation of the sulfhydryl groups of the enzyme.

CONCLUSIONS

Considering that creatine kinase is a crucial enzyme for retina energy homeostasis, in case cystine leaves lysosome these results provide a possible mechanism for cystine toxicity and also another beneficial effect for the use of cysteamine in patients with cystinosis.

Inhibition of creatine kinase activity from rat cerebral cortex by 3-hydroxykynurenine

3-hydroxykynurenine, a tryptophan metabolite, is known to be potential neurotoxic in some neurodegenerative disorders. However, the molecular mechanisms of toxicity are not well understood. Creatine kinase plays a key role in energy metabolism of tissues with intermittently high and fluctuating energy requirements, such as nervous tissue. This study investigated the in vitro effect of 3-hydroxykynurenine on creatine kinase activity in the brain cortex of rats. The results indicated that low micromolar 3-hydroxykynurenine concentrations inhibit uncompetitively mitochondrial and cytosolic creatine kinase activities in a time and dose-dependent way. Inhibition was prevented, but not reversed by incubation with reduced glutathione, dithiothreitol and ascorbic acid plus trolox, suggesting adduct formation. The assay under nitrogen atmosphere suggested that the inhibition was caused by products of 3-hydroxykynurenine autoxidation. Determination of thiol groups suggested that adducts between the enzyme and autoxidation products of 3-hydroxykynurenine were not formed with sulfhydryl groups. The interaction plot between tryptophan and 3-hydroxykynurenine suggested different sites of action on creatine kinase with cross-inhibition. Considering the importance of creatine kinase for the maintenance of energy homeostasis in the brain, it is conceivable that an alteration of this enzyme activity may be one of the mechanisms by which 3-hydroxykynurenine might be neurotoxic.

Inhibition of creatine kinase activity by cystine in the kidney of young rats

Nephropathic cystinosis is a lethal genetic disease caused by a lysosomal transport disorder leading to intralysosomal cystine accumulation in all tissues. Cystinosis is the most common inherited cause of Fanconi syndrome, but the mechanisms by which cystine causes tissue damage are not fully understood. Thiol-containing enzymes are critical for renal energy metabolism and may be altered by disulfides like cystine. Therefore, in the present study our main objective was to investigate the in vivo and in vitro effects of cystine on creatine kinase, which contains critical thiol groups in its structure, in the kidney of young Wistar rats. We observed that cystine inhibited in vivo and in vitro the enzyme activity and that this inhibition was prevented by cysteamine and glutathione. The results suggest oxidation of essential sulfhydryl groups necessary for creatine kinase function by cystine. Considering that creatine kinase and other thiol-containing enzymes are crucial for renal energy metabolism, and programmed cell death occurs in situations of energy deficiency, the enzyme inhibition caused by cystine released from lysosomes might be a mechanism of tissue damage in patients with cystinosis.

Alanine prevents the reduction of pyruvate kinase activity in brain cortex of rats subjected to chemically induced hyperphenylalaninemia

The mechanisms by which phenylalanine is toxic to the brain in phenylketonuria are not fully understood. Considering that brain glucose metabolism is reduced in these patients, our main objective was to determine pyruvate kinase activity in brain cortex of rats subjected to acute and chronic chemically induced hyperphenylalaninemia. The effect of alanine administration on the enzyme activity in the treated rats was also investigated. We also studied the in vitro effect of the two amino acids on pyruvate kinase activity in brain cortex of nontreated rats. The results indicated that phenylalanine inhibits pyruvate kinase in vitro and in vivo and that alanine prevents the inhibitory effect of phenylalanine on the enzyme activity. Considering the crucial role pyruvate kinase plays in glucose metabolism in brain, it is possible that inhibition of this enzyme activity may contribute to the brain damage characteristic of this disease.

Inhibition of the mitochondrial respiratory chain by phenylalanine in rat cerebral cortex

Phenylketonuria (PKU) is biochemically characterized by the accumulation of phenylalanine (Phe) and its metabolites in tissues of affected children. Neurological damage is the clinical hallmark of PKU, and Phe is considered the main neurotoxic metabolite in this disorder. However, the mechanisms of neurotoxicity are poorly known. The main objective of the present work was to measure the activities of the mitochondrial respiratory chain complexes (RCC) and succinate dehydrogenase (SDH) in brain cortex of Wistar rats subjected to chemically induced hyperphenylalaninemia (HPA). We also investigated the in vitro effect of Phe on SDH and RCC activities in the cerebral cortex of 22-day-old rats. HPA was induced by subcutaneous administration of 2.4 micromol/g body weight alpha-methylphenylalanine, a phenylalanine hydroxylase inhibitor, once a day, plus 5.2 microM/g body weight phenylalanine, twice a day, from the 6th-21st postnatal day. The results showed a reduction of SDH and complex I + III activity in brain cortex of rats subjected to HPA. We also verified that Phe inhibited the in vitro activity of complexes I + III, possibly by competition with NADH. Considering the importance of SDH and RCC for the maintenance of energy supply to brain, our results suggest that energy deficit may contribute to the Phe neurotoxicity in PKU.