Enzymatic Indices Research Articles

Comparative Analysis of the Effects of Different Substrates on Protease Production by Penicillium spp. Isolated from the Amazon

The genus Penicillium is widely recognized for its ability to produce a diverse range of enzymes, including proteases, which play crucial roles in various biotechnological applications. This study investigated the influence of three distinct inducers (skim milk, gelatin, and a combination of skim milk and gelatin) on protease production by different Penicillium species, using the cup-plate method—a qualitative technique that detects proteolytic activity in solid media. The proteolytic activity of Penicillium species was assessed by measuring degradation halos in culture media supplemented with these inducers. The results demonstrated that skim milk was the most effective inducer, yielding the highest Enzyme Index (EI) values. The highest EI was observed for P. citrinum 414 (3.6), followed by P. oxalicum and P. sumatraense, both with EIs of 3.3. The strains P. citrinum 409, P. paxilli, P. citrinum 457, and Penicillium spp. 5 and 546 exhibited EIs ranging from 3.0 to 3.2. The analysis of degradation halos highlighted that both substrate type and cultivation conditions significantly influence protease production. This study enhances our understanding of the enzymatic potential of Penicillium species and underscores the importance of optimizing cultivation parameters to maximize protease production, which has broad potential applications in industrial processes.

Microbial enzymatic indices for predicting composting quality of recalcitrant lignocellulosic substrates.

Three different enzymes alkaline phosphatase, Urease and Dehydrogenase were measured during this study to monitor the organic matter dynamics during semi-industrial composting of mixture A with 1/3 sludge+2/3 palm waste and mixture B with ½ sludge+1/2 palm waste. The phosphatase activity was higher for Mix-A (398.7 µg PNP g-1 h-1) than Mix-B (265.3 µg PNP g-1 h-1), while Mix-B (103.3 µg TPF g-1d-1) exhibited greater dehydrogenase content than Mix-A (72.3 µg TPF g-1 d-1). That could contribute to the dynamic change of microbial activity together with high amounts of carbonaceous substrates incorporated with the lignocellulosic. The gradual increase in the dehydrogenase from the compost Mix-A implies that high lignocellulosic substrate requires gradual buildup of dehydrogenase activity to turn the waste into mature compost. A higher pick of urease with a maximum activity of 151.5 and 122.4 µg NH4-N g-1 h-1 were reported, respectively for Mix-A and B. Temperature and pH could also influence the expression of enzyme activity during composting. The machine learning well predicted the compost quality based on NH3/NO3, C/N ratio, decomposition rate and, humification index (HI). The root mean square error (RMSE) values were 1.98, 1.95, 4.61%, and 4.1 for NH+ 3/NO- 3, C/N ratio, decomposition rate, and HI, respectively. The coefficient of determination between observed and predicted values were 0.87, 0.93, 0.89, and 0.94, for the r NH3/NO3, C/N ratio, decomposition rate, and HI. Urease activity significantly predicted the C/N ratio and HI only. The profile of enzymatic activity is tightly linked to the physico-chemical properties, proportion of lignocellulosic-composted substrates. Enzymatic activity assessment provides a simple and rapid measurement of the biological activity adding understunding of organic matter transformation during sludge-lignocellulosic composting.

Unveiling the Impact of Soil Prebiotics on Rhizospheric Microbial Functionality in Zea mays L.

Prebiotics, a subset of biostimulants, have garnered attention for their potential to enhance soil conditions and promote plant growth, offering a promising alternative to conventional agricultural inputs. This study explores how two commercial prebiotics, K1® and NUTRIGEO L® (SPK and SPN), impact soil functions compared to a control (SP). The experiment involved agricultural soil amended with organic wheat straws and cultivated with Zea mays L. Previous research demonstrated substantial effects of these prebiotics on plant biomass, soil parameters, and microbial community ten weeks after application. The present study delves deeper, focusing on soil microbial abundance, enzyme activities, and metabolic diversity. Analysis revealed that SPN notably increased the fungi-to-bacteria ratio, and both prebiotics elevated the activity of several key enzymes. SPN enhanced α-glucosidase and β-galactosidase activities, while SPK increased arylsulfatase, phosphatase, alkaline phosphatase, and urease activities. Enzymatic indexes confirmed the positive impact on soil functional diversity and fertility. Additionally, prebiotic treatments showed distinct metabolic profiles, with SPK degrading eleven carbon sources more rapidly across five groups and SPN accelerating the decomposition rate of four carbon sources from three groups. These findings highlight the ability of prebiotics to shape microbial communities and enhance soil fertility by modulating their functional activity and diversity.

Novel nucleus-localized GRAM protein encoding OsGRAM57 gene enhances salt tolerance through ABA-dependent pathway and modulated carbohydrate metabolism

GRAM (Glucosyltransferases-like GTPase activators and Myotubularin) domain-encoding proteins play pivotal roles in plant growth and responses to biotic stresses. Yet, their influence on abiotic stress responses has remained enigmatic. This study unveils a novel nucleus-localized OsGRAM57, a GRAM protein-encoding gene and its profound regulatory functions in enhancing salt stress tolerance using Arabidopsis thaliana as a model plant. OsGRAM57-OEX (OsGRAM57-OEX) lines displayed significant enhancement in salt tolerance, modulated physiological, biochemical, K+/Na+ ratios, and enzymatic indices as compared to their wild-type (WT). Furthermore, OsGRAM57-OEX seedlings demonstrate increased levels of endogenous abscisic acid (ABA) and other phytohormones, while metabolic profiling revealed enhanced carbohydrate metabolism. Delving into the ABA signaling pathway, OsGRAM57 emerged as a central regulator, orchestrating the expression of genes crucial for salt stress responses, carbohydrate metabolism, and ABA signaling. The observed interactions with target genes and transactivation assays provided additional support for OsGRAM57's pivotal role. These findings underscore OsGRAM57's positive influence on the ABA pathway and affirm its capacity to enhance salt tolerance through an ABA-dependent pathway and fine-tuned carbohydrate metabolism. In summary, this new study reveals the previously undiscovered regulatory roles of OsGRAM57 in Arabidopsis abiotic stress responses, offering promising ways for strengthening plant resilience in the face of adverse environmental conditions.

Protective effect of ginsenoside Rb1 against aconitine cardiotoxicity studied by myocardial injury, action potential, and calcium signaling

Aconitine is the main active component of Aconitum plants. Although aconitine has effects that include strengthening the heart, analgesia, anti-tumor, and immune-regulating effects, aconitine has both efficacy and toxicity, especially cardiotoxicity. Severe effects can include arrhythmia and cardiac arrest, which limits the clinical application of aconitine-containing traditional Chinese medicine. Ginsenoside Rb1(Rb1) is mainly found in plants, such as ginseng and Panax notoginseng, and has cardiovascular-protective and anti-arrhythmia effects.This study aimed to investigate the detoxifying effects of Rb1 on aconitine cardiotoxicity and the electrophysiological effect of Rb1 on aconitine-induced arrhythmia in rats.Pathological analysis, myocardial enzymatic indexes, and Western blotting were used to investigate the ameliorating effect of Rb1 on aconitine cardiotoxicity. Optical mapping was used to evaluate the effect of Rb1 on action potential and calcium signaling after aconitine-induced arrhythmia.Rb1 inhibited pathological damage caused by aconitine, decreased myocardial enzyme levels, and restored the balance of apoptotic protein expression by reducing the expression of Bax and cleaved caspase 3 and increasing the expression of Bcl-2, thereby reducing myocardial damage caused by aconitine. Rb1 also reduced the increase in heart rate caused by aconitine, accelerated action potential conduction and calcium signaling, and reduced the dispersion of action potential and calcium signal conduction.Rb1 reduced the cardiotoxicity of aconitine by attenuating aconitine-induced myocardial injury and inhibiting the aconitine-induced retardation of ventricular action potential and calcium signaling in rats.

Effect of Biochar on Vermicompost Production: Chemical, Biochemical, and Biological Properties

Farm and industrial residues must be adequately managed to avoid negative environmental implications. In this study, our objective was to evaluate (i) the impact of the co-production of vermicompost using grape bagasse and biochar (BC) on the yield and biochemical, chemical, and biological properties of vermicompost; (ii) the effect of BC on earthworms (Eisenia fetida Sav.). The vermicompost was co-produced over 5 months (n = 4 per treatment) using (i) grape bagasse as the substrate, (ii) earthworms (Eisenia fetida Sav.), and (iii) three BCs (eucalyptus sawdust BC, pig manure BC, and carbonaceous material from poultry litter CM) at 2% (w/w). A control without BC was included. The chemical, microbiological (activity and respiration), enzymatic properties, and enzymatic indices were characterized. After the incubation period, vermicompost yield increased with the application of the three BCs (25% on average). The number of adult earthworms was not affected by any of the BCs. Compared to treatments without BC, those with pig manure BC and eucalyptus BC resulted in maintained or significantly decreased enzymatic activity, indicating that the vermicompost was at an advanced stage of maturity. Eucalyptus BC significantly enriched the C content of the vermicompost by 4.3%, maintaining respiration rates at 18% lower than the treatment without BC. Additionally, pig manure BC generated the lowest respiration rate in the vermicompost (20% lower). We conclude that BC has a positive influence on the vermicompost process, stabilizing organic matter (especially pig manure BC) and improving the potential of vermicompost to store C (when high-C-content BCs are applied).

Enzymatic Indicators in Vaporized Hydrogen Peroxide Decontamination Cycles: Application-related Research focusing on Fractional Kill Time (FKT) and Reverse Fractional Kill Time (RFKT) Studies

The accepted standard from a regulatory perspective for vaporized hydrogen peroxide (vH2O2) cycle validation is the use of biological indicators (BIs). Novel enzymatic indicators (EIs) are gaining more importance in this field, relying on specific enzymatic reactions for their functionality. The aim of this work is to determine how enzymatic indicators can contribute to the cycle development process. Emphasis was placed on the initial informative study, the fractional kill time study, which is a basis for future studies. The results indicate that enzymatic indicators have the potential to facilitate further development of the cycle. This requires an analysis of the determined data, measured in relative light units (RLU), and aligning it with the BI growth, resulting in Full Kill/ No Kill limits. The use of enzymatic indicators for decontamination cycle development opens new perspectives and holds considerable potential for practical use in the development and validation of decontamination processes.

Use of EIs in Vapour Phase Hydrogen Peroxide Decontamination Cycle Optimisation and Rapid Validation

AstraZeneca investigated the use of Enzymatic Indicators (EIs) in order to optimise their Sterility Testing Isolator gassing cycles. The quantitative nature of the EI data has enabled identification and successful validation of an optimised cycle, which has halved the original gassing cycle, leading to reduced costs, reduced periods of Isolator downtime and increased overall productivity. When completing the validation, the EI data was also used to provide greater confidence in the instance of erroneous Biological Indicator results, and as such has also expedited validation of a new ‘wet’ vaporised H2O2 generator. In addition, the EI data provided increased data across the sterility isolator chamber, allowing for confidence that sufficient cycle decontamination is achieved in all challenge locations, and as such there is no risk of BI failures upon requalification. EIs are therefore regarded as a beneficial companion for BI data when looking to optimise productivity of current isolators, and when used for validation of new equipment.

Effects of protoscoleces excretory-secretory products of Echinococcus granulosus on hepatocyte growth, function, and glucose metabolism

Cystic echinococcosis (CE) is one of the most widespread and harmful zoonotic parasitic diseases, which most commonly affects the liver. In this study, we characterized multiple changes in mouse hepatocytes following treatment with excretory-secretory products (ESPs) of Echinococcus granulosus protoscoleces (Eg-PSCs) by a factorial experiment. The cell counting kit-8 assay (CCK-8), the 5-ethynyl-2′-deoxyuridine (EdU) assay, and flow cytometry were used to detect the growth of hepatocytes. Inverted microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to observe the morphology and ultrastructure of hepatocytes. An automatic biochemical analyzer and an ELISA detection kit were used to determine six conventional hepatocyte enzymatic indices, the levels of five hepatocyte-synthesized substances, and the contents of glucose and lactate. Western blot analysis was conducted to analyze the protein expression of three apoptosis-related proteins, Bax, Bcl-2, cleaved caspase-3, and six glucose metabolism pathways rate-limiting enzymes in hepatocytes. The results showed that ESPs inhibited hepatocyte proliferation and promoted hepatocyte apoptosis. The cell membrane and microvilli of hepatocytes changed, and the nucleus, mitochondria and rough endoplasmic reticulum were damaged to varying degrees. The contents of iron, albumin (ALB), uric acid (UA) and urea were increased, and the activities of six enzymes in hepatocytes were increased except for the decrease of transferrin (TRF). The expression levels of all six key enzymes in the glucose metabolism pathway in hepatocytes were reduced. Our characterization provides a basis for further research on the pathogenesis, prevention and treatment of CE.

Decrease of Cellular Communication Network Factor 1 (CCN1) Attenuates PTZ-Kindled Epilepsy in Mice.

To investigate the molecular mechanism of communication network factor 1 (CCN1) regulating pentylenetetrazol (PTZ)-induced epileptogenesis, deepen the understanding of epilepsy seizure pathogenesis, and provide new drug action targets for its clinical prevention and treatment. Differentially expressed genes (DEGs) on microarrays GSE47516 and GSE88992 were analyzed online using GEO2R. Pathway enrichment and protein-protein interaction network (PPI) analysis of DEGs were carried out using Metascape. Brain tissue samples of severe traumatic brain injury patients (named Healthy group) and refractory epilepsy patients (named Epilepsy group) were obtained and analyzed by qRT-PCR and immunohistochemistry (IHC) staining. A PTZ-induced epilepsy mouse model was established and verified. Morphological changes of neurons in mouse brain tissue were detected using hematoxylin and eosin (HE) staining. qRT-PCR was conducted to detect the mRNA expressions of apoptosis-associated proteins Bax, Caspase-3 and bcl2. TUNEL staining was performed to detect brain neuron apoptosis. The levels of myocardial enzymology, GSH, MDA and ROS in blood of mouse were detected by biochemical assay. CCN1 expression was increased in epilepsy brain tissue samples. CCN1 decreasing effectively prolongs seizure incubation period and decreases seizure duration. Silencing of CCN1 also reduces neuronal damage and apoptosis, decreases mRNA and protein expression of proapoptotic proteins Bax and Caspase-3, increases mRNA expression of antiapoptotic protein Bcl2. Moreover, decrease of CCN1 decreases myocardial enzymatic indexes CK and CK-MB levels, reduces myocardial tissue hemorrhage, and relieves oxidative stress response in hippocampal and myocardial tissue. CCN1 expression is increased in epileptic samples. CCN1 decreasing protects brain tissue by attenuating oxidative stress and inhibiting neuronal apoptosis triggered by PTZ injection, which probably by regulating Nrf2/HO-1 pathway.

Enzymatic potential of endophytic fungi: xylanase production by Colletotrichum boninense from sugarcane biomass.

Endophytic fungi constitute a major part of the still unexplored fungal diversity and have gained interest as new biological sources of natural active compounds, including enzymes. Endophytic fungi were isolated from soybean leaves and initially screened on agar plates for the production of CMCase (carboxymethylcellulase), xylanase, amylase and protease. The highest Enzymatic Indexes (IE) were verified for xylanase (2.14 and 1.31) with the fungi M6-A6P5F2 and M12-A5P3F1.2 and CMCase (1.92 and 1.62) with the fungi M13-A9P2F1 and M12-A5P3F1.2, respectively. The production of xylanase and CMCase by the selected fungi was evaluated in submerged cultivation using beechwood xylan and carboxymethylcellulose (CMC), as well as sugarcane straw and bagasse in different ratios as carbon sources. Both types of lignocellulosic biomass proved to be good inducers of enzymatic activity. The best xylanase producer among the isolates was identified as Colletotrichum boninense. With this fungus, the highest xylanase activity was obtained with a sugarcane straw-bagasse mixture in a 50:50 ratio (383.63 U mL-1), a result superior to that obtained with the use of beechwood xylan (296.65 U mL-1). Regardingthe kinetic behavior of the crude xylanase, there was found optimal pH of 5.0 and optimal temperatures of 50°C and 60°C. At 40°C and 50°C, xylanase retained 87% and 76% of its initial catalytic activity, respectively. These results bring new perspectives on bioprospecting endophytic fungi for the production of enzymes, mainly xylanase, as well as the exploitation of agro-industrial by-products, such as sugarcane straw and bagasse.

Assessment of Vibrio populations in a transect of Rhizophora mangle in Punta Galeta, Panamá: culture-dependent analyses reveal biotechnological applications.

Rhizophora mangle is considered an ecological niche for microorganisms with potentially novel and complex degrading enzymes. To characterize Vibrio populations using culture-dependent methods, using samples collected from sediments and water along a red mangrove transect composed of three sites. Strains were characterized according to their distribution, capacity to degrade of organic matter and other environmental parameters. Additionally the sequence diversity was assessed using 16S rRNA sequencing. Bacterial densities were strongly associated with temperature and salinity. A total of 87 good-quality sequences representing the isolates from the three sites, were binned into eight OTUs (Operational taxonomic units). Taxonomic assignment indicated that the dominant members were Vibrionaceae. Beta diversity analyses showed that bacterial communities clustered by sample source rather than spatial distribution, and that alpha diversity was found to be higher in water than in sediment. Three percent of the strains from water samples could degrade carboxyl-methyl cellulose with the smallest enzymatic indexes compared to 4 % of the strains from sediment samples that showed the highest enzymatic indexes. Two strains identified as Vibrio agarivorans degraded cellulose and agarose, producing the highest enzymatic indexes. We found higher bacterial densities and diversity in the bacterial communities of the water samples compared to the sediment, with different OTUs including those similar to Ferrimonas, Providencia, or Shewanella which were not isolated in the sediment. Vibrio OTUs were shown to degrade cellulose in both sample types. The results of this study highlight the importance of red mangroves as Vibrio habitats and as reservoirs of potential enzyme sources with biotechnological applications.

Isolation and Screening of potent cellulolytic soil fungi from Raipur city of Chhattisgarh State, India

The current research focuses on the diversity of fungal isolates obtained from the soil and their ability to produce cellulolytic enzymes. Out of 76 colonies obtained, 11 fungal colonies were isolated viz. Aspergillus , Humicola and Rhizopus being the major genera of the isolates. From the 11 isolates, the identification of potent cellulase producing cultures was done using qualitative carboxy methyl cellulase screening test. Following the preliminary screening, five cultures viz., Aspergillus sydowii , Humicola sp - 1, Aspergillus niger , Aspergillus ustus , Aspergillus flavus were identified to be potent with enzymatic indices ranging from 1.25 to 2.29. These were further selected for quantitative enzyme analysis. Aspergillus sydowii was found to have highest enzymatic activity and Aspergillus flavus was found to have the least enzymatic activity. Our findings revealed that Aspergillus sydowii appeared to be a promising candidate for cellulase production and can be utilized for waste recycling and other biotechnological applications.

Communities of culturable freshwater fungi present in Antarctic lakes and detection of their low-temperature-active enzymes.

We evaluated the diversity and enzymatic activities of culturable fungi recovered from cotton baits submerged for 2years in Hennequin Lake, King George Island, and from benthic biofilms in Kroner Lake, Deception Island, South Shetland Islands, maritime Antarctica. A total of 154 fungal isolates were obtained, representing in rank abundance the phyla Ascomycota, Basidiomycota and Mortierellomycota. Thelebolus globosus, Goffeauzyma sp., Pseudogymnoascus verrucosus and Metschnikowia australis were the most abundant taxa. The fungal community obtained from the biofilm was more diverse and richer than that recovered from the cotton baits. However, diversity indices suggested that the lakes may harbour further fungal diversity. The capabilities of all cultured fungi to produce the extracellular enzymes cellulase, protease, lipase, agarase, carrageenase, invertase, amylase, esterase, pectinase, inulinase and gelatinase at low temperature were evaluated. All enzymes were detected, but the most widely produced were protease and pectinase. The best enzymatic indices were obtained from Holtermanniella wattica (for invertase, esterase), Goffeauzyma sp. (amylase), Metschnikowia australis (protease), Mrakia blollopis (cellulase, pectinase), Pseudogymnoascus verrucosus (agarase, carrageenase) and Leucosporidium fragarium (inulinase). The detection of multiple enzymes reinforces the ecological role of fungi in nutrient cycling in Antarctic lakes, making nutrients available to the complex aquatic food web. Furthermore, such low-temperature-active enzymes may find application in different biotechnological processes, such as in the textile, pharmaceutical, food, detergent and paper industries, as well as environmental application in pollutant bioremediation processes.

Field Efficacy of Proteolytic Entomopathogenic Fungi against Ceratovacuna lanigera Zehntner

Entomopathogenic fungi (EPF) are regarded as viable alternatives to insect pest control chemicals that contain a large amount of protease enzyme, which degrades the proteinaceous substances in insect cuticles. The aim of this study was to evaluate the field efficacy of protease-producing EPF against Ceratovacuna lanigera, and to assess the persistence of the Ceratovacuna lanigera, on sugarcane leaves. A total of 10 protease-producing fungi isolates were cultured from different agricultural soils, and identified as Purpureocillium lilacinum on the basis of the morphological features and molecular data, using ITS 1-5.8 S-ITS 2 of the rDNA sequences. The proteolytic activity of the isolates was assessed and expressed as an Enzyme Index (EI). Three isolates (PLTP5, PLPS8, and PLMC11) were found to be the best enzyme producers among the isolates, presenting EI values > 2.0 at 24 h, 48 h, and 72 h during incubation. These three isolates also gave the best results in terms of lethal concentrations (LC50 and LC90) and lethal time (LT50 and LT90) values, based on laboratory virulence evaluation, and were therefore selected for field application; commercial B. bassiana (GHA) was applied as standard treatment. An oil-based formulation of conidia (1 × 108 mL−1) of the isolates was applied in a sugarcane field experiment, with an interval of 10 days for four times. The results revealed that P. lilacinum (PLTP5) showed the highest reduction in the C. lanigera population, of 28.75, 56.02, 67.42, and 77.21%, respectively, after the first, second, third, and fourth spraying. The persistence of the conidia of the isolates on the sugarcane leaves was assessed. Per cent reductions in the conidia population, of 36.94–45.23%, 69.36–80.15%, and 81.75–92.96%, respectively, were found after three, six, and nine days of application. The application impact of EPF on the yield component and sugar content was evaluated. Purpureocillium lilacinum (PLTP5) showed the highest increase, of 18.15, 17.83, 15.07, 11.88, 23.73, and 19.38%, respectively, for leaf length, leaf width, cane height, cane girth, cane weight, and sugar content (brix). Our study indicated that P. lilacinum (PLTP5) was the most effective EPF against C. lanigera in field conditions, and also showed the highest proteolytic activity. Consequently, protease was considered the essential factor regulating the efficacy of P. lilacinum against C. lanigera. Protease would be useful, therefore, as an eco-friendly alternative to chemical pesticides, for the sustainable management of C. lanigera.

Changes in lipids metabolism indices as a result of different form of selenium supplementation in chickens

Selenium is an essential element that is important for many metabolic processes. Feed components used in chicken nutrition, especially cereals, may be deficient in selenium, hence selenium supplementation is necessary. Taking into account the progress in breeding, and thus the higher demand of birds for this element, it seems obvious to investigate an increased selenium dose in the diet of chickens. The aim of the study was to evaluate the effect of feed enriched with different forms of selenium at an increased dose of 0.5 mg/kg feed on the profile and metabolism of fatty acids in the breast muscle and liver of chickens. The study was conducted on 300 Ross 308 chickens reared for 42 days under standard conditions. The control group received feed supplemented with sodium selenite at a dose of 0.3 mg/kg feed. The research groups received different forms of selenium (sodium selenate, selenised yeast, nano-selenium) at an increased dose of 0.5 mg/kg feed. The study showed that the administration of different forms of selenium in the feed affected its concentration in the breast muscle and liver (p ≤ 0.01). Nano-selenium was found to have a high bioavailability, but also a lower risk of toxicity compared to other forms of selenium. Using different forms of selenium (p ≤ 0.01) at a dose of 0.5 mg/kg feed can significantly modify the fatty acid profile, lipid and enzymatic indices of fatty acid metabolism in breast muscle and liver.

In vivo and in vitro protective effects of shengmai injection against doxorubicin-induced cardiotoxicity

Context Shengmai injection (SMI) has been used to treat heart failure. Objective This study determines the molecular mechanisms of SMI against cardiotoxicity caused by doxorubicin (DOX). Materials and methods In vivo, DOX (15 mg/kg) was intraperitoneally injected in model, Dex (dexrazoxane), SMI-L (2.7 mL/kg), SMI-M (5.4 mL/kg), and SMI-H (10.8 mL/kg) for 7 consecutive days. Hematoxylin-eosin (HE) and Masson staining were used to evaluate histological changes, and cardiomyocyte apoptosis was identified using TdT-mediated dUTP nick-end labelling (TUNEL). Enzymatic indexes were determined. mRNA and protein expressions were analysed through RT-qPCR and Western blotting. In vitro, H9c2 cells were divided into control group, model group (2 mL 1 μM DOX), SMI group, ML385 group, and SMI + ML385 group, the intervention lasted for 24 h. mRNA and protein expressions were analysed. Results SMI markedly improved cardiac pathology, decreased cardiomyocyte apoptosis, increased creatine kinase (CK), lactate dehydrogenase (LDH), malondialdehyde (MDA), decreased superoxide dismutase (SOD). Compared with the model group, the protein expression of nuclear factor erythroid2-related factor 2 (Nrf2) (SMI-L: 2.42-fold, SMI-M: 2.67-fold, SMI-H: 3.07-fold) and haem oxygenase-1(HO-1) (SMI-L: 1.64-fold, SMI-M: 2.01-fold, SMI-H: 2.19-fold) was increased and the protein expression of kelch-like ECH-associated protein 1 (Keap1) (SMI-L: 0.90-fold, SMI-M: 0.77-fold, SMI-H: 0.66-fold) was decreased in SMI groups and Dex group in vivo. Additionally, SMI dramatically inhibited apoptosis, decreased CK, LDH and MDA levels, and enhanced SOD activity. Our results demonstrated that SMI reduced DOX-induced cardiotoxicity via activation of the Nrf2/Keap1 signalling pathway. Conclusions This study revealed a new mechanism by which SMI alleviates DOX-induced 45 cardiomyopathy by modulating the Nrf2/Keap1 signal pathway.

Comparison of the Effect of Maximal and Submaximal Aerobic Physical Activity on Saliva Enzymatic and Non-Enzymatic Antioxidant Indices in Middle-Age Women

Background & Objective: Some studies have demonstrated that aerobic exercise can reinforce antioxidant defensive system. To this end, the present study aimed to compare the effect of maximal and submaximal aerobic physical activity on saliva enzymatic and non-enzymatic antioxidant indices in middle-aged women. Materials & Methods: In this quasi-experimental study, 24 women (35-45 years, Weight: 67.41±5.03, Height: 161.83±2.98 and BMI: 25.74±2.01) were selected purposefully and voluntarily who were randomly categorized into two groups, Maximal Aerobic Physical Activity (MAPA) and Submaximal Physical Activity (SAPA) (n=12/group). SAPA were done with 50 to 70 percentage of heart rate reserve for 3 sessions/week for 6 weeks. To do MAPA, Bruce Protocol (seven stages for 3 minutes) was applied. It started with 10% incline and 1.7 miles/hour speed and continued with 2% increase for every 3 minutes until exhaustion, 3 sessions/week for 6 weeks. Required saliva samples were gathered before the first session and 24 hours after the last session of exercise to be applied to evaluate Catalase, Superoxide dismutase, Malondialdehyde enzyme, and total antioxidant capacity. Data were analyzed using an independent T-test (P≤ 0.05). Results: Research results represented a significant difference in saliva enzyme indices for MAPA and SAPA groups: Catalase (PCAT= 0.003), Malondialdehyde (PMDA=0.001), and total antioxidant capacity (PTAC= 0.04). MAPA group showed higher average. In addition, the results indicated no significant difference in dismutase superoxide enzyme levels (PSOD=0.88) in MAPA and SAPA groups. Conclusion: According to the reported results, it may be concluded that due to its ability to increase antioxidant enzyme secretion, MAPA is applied to cope with oxidative stress.

Neurobehavioral toxic effects of perinatal oral exposure to lithium on the developmental motor reflexes, cognitive dysfunction and brain oxidative stress of mice offspring

In the present study, the perinatal oral exposure of pregnant mice to 15 and 30mg/kg lithium (lithium chloride) in their drinking water resulted in a significant and dose-dependent reduction in postnatal body weight gain, delays in opening of the eyes and appearance in the body hair fuzz, and deficits in the sensory motor reflexes of the mice pups during weaning period (from the day of birth to postnatal day21). At adolescent and adult ages of the male offspring, a significant and dose-dependent deficit was also observed in their learning capability (at PD25), and cognitive behavior (at PD30-36). Furthermore, a significant and dose-dependent disturbance in the levels of neurotransmitters like dopamine (DA) and serotonin (5-HT); non-enzymatic oxidative stress (OS) indices like thiobarbituric acid-reactive substances (TBARS) and total reduced glutathione (GSH); and enzymatic OS indices like glutathione S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD) were observed in the forebrain region of the offspring at post-natal day (PD)7, PD14, PD21, PD30, and PD36. Thus, perinatal lithium exposure can affect the in utero developing fetus, raising the concerns for a potential neurotoxic hazards and a longer lasting cognitive dysfunction. A reduced use of lithium during pregnancy is of crucial importance in preventing lithium -induced neurotoxicity in the offspring.

Experimental study on liver injury induced by intraperitoneal hypertension under mechanical ventilation

To investigate the effects of mechanical ventilation on liver cytological and enzymatic indexes in abdominal compartment syndrome (ACS) by establishing a porcine model of abdominal hypertension. Six healthy adult pigs were selected. After general anesthesia, they were intubated and given ventilator assisted breathing. The breathing mode was volume controlled ventilation (VCV), tidal volume (VT) 10 mL/kg, respiratory rate (RR) 16 time/min, fraction of inspiration oxygen (FiO2) 0.40, positive end expiratory pressure (PEEP) 5 cmH2O (1 cmH2O = 0.098 kPa). Intraperitoneal pressure was simulated by injecting normal saline into the pressurized water sac, and the pressure was measured once every 50 mL of normal saline. 5 mL of blood was collected from ear vein every 1 hour before and 4 hours after operation for liver enzyme examination. 4 hours after operation, the animals were sacrificed and the liver was collected to observe pathological changes under light microscope. Six pigs were successfully modeled. The RR and heart rate (HR) of the animals remained stable. No one suffered from barotrauma or death during the experiment. There was a positive correlation between abdominal pressure and abdominal volume increase (r2 = 0.839 6, P = 0.003 7). There were no significant differences in the levels of alanine aminotransferase (ALT), alkaline phosphatase (ALP) and cholinesterase (ChE) preoperative and 1, 2, 3, 4 hours after operation. As time went on, aspartate aminotransferase (AST) increased first and then decreased, and increased significantly at 1 hour after operation (U/L: 46.84±8.57 vs. 23.35±5.14, P < 0.05), and decreased significantly 2, 3, 4 hours after operation (U/L: 16.33±3.58, 14.54±3.35, 15.44±3.21 vs. 23.35±5.14, all P < 0.05). The level of γ-glutamyltranspeptidase (GGT) increased and then decreased, but there was significant difference only at 1 hour after operation, compared with baseline (U/L: 101.20±17.79 vs. 51.34±9.13, P < 0.05). Under the light microscope, there were dilation and congestion of interlobular vein, dilation of interlobular bile duct, hyperplasia of small bile duct, hyperplasia of connective tissue in portal area, infiltration of a large number of acute and chronic inflammatory cells, swelling of hepatocytes, light staining of cytoplasm, balloon like transformation of some cells, and punctate necrosis. Abdominal hypertension under mechanical ventilation can cause obvious enzyme changes and cytological damage of liver.