Enzyme Activity Levels Research Articles

Low acaricide resistance levels in citrus orchards field populations of the invasive spider mite Eutetranychus orientalis (Acari: Tetranychidae) collected from southern Türkiye

The citrus brown mite Eutetranychus orientalis (Klein), is known as one of the most significant pests in citrus growing areas worldwide. It has recently caused outbreaks in the Mediterranean region of Türkiye. This study aimed to determine the resistance levels of E. orientalis populations between 2020 and 2021 collected from 9 commercial citrus orchards in Adana province against 5 different acaricides, in order to determine whether the observed population outbreak was due to acaricide resistance. The resistance ratios were changed between 1.67 and 2.50, 1.00–2.53, 1.85–3.68, 1.30–2.65, and 1.93–3.13-fold for abamectin, etoxazole, fenbutatin oxide, pyridaben, and spirodiclofen, respectively. The enzyme activity levels of carboxylesterase, glutathione S-transferase, and cytochrome P450 monooxygenase ranged between 1.00 and 1.13, 1.02–1.52, and 0.94–1.72-fold, respectively. As a result of the resistance study carried out for the first time on this species in Türkiye, the resistance ratios were determined to be low for E. orientalis against acaricides. Although the current resistance rates were low, certain populations exhibited a noteworthy surge in enzyme activities when compared to the susceptible population. Based on these findings, it was concluded that by implementing an appropriate resistance management strategy using acaricides with different modes of action, it is possible to prevent potential resistance development and use these acaricides effectively on this spider mite species for many years through rotation.

Strategies to Maintain Redox Homeostasis in Yeast Cells with Impaired Fermentation-Dependent NADPH Generation.

Redox homeostasis is the balance between oxidation and reduction reactions. Its maintenance depends on glutathione, including its reduced and oxidized form, GSH/GSSG, which is the main intracellular redox buffer, but also on the nicotinamide adenine dinucleotide phosphate, including its reduced and oxidized form, NADPH/NADP+. Under conditions that enable yeast cells to undergo fermentative metabolism, the main source of NADPH is the pentose phosphate pathway. The lack of enzymes responsible for the production of NADPH has a significant impact on yeast cells. However, cells may compensate in different ways for impairments in NADPH synthesis, and the choice of compensation strategy has several consequences for cell functioning. The present study of this issue was based on isogenic mutants: Δzwf1, Δgnd1, Δald6, and the wild strain, as well as a comprehensive panel of molecular analyses such as the level of gene expression, protein content, and enzyme activity. The obtained results indicate that yeast cells compensate for the lack of enzymes responsible for the production of cytosolic NADPH by changing the content of selected proteins and/or their enzymatic activity. In turn, the cellular strategy used to compensate for them may affect cellular efficiency, and thus, the ability to grow or sensitivity to environmental acidification.

Protecting celtuce (Lactuca sativa L. var. augustana) slices against storage-induced oxidative stress and discoloration by using diode laser exposure

Diode laser irradiation is a novel approach applied to preserve the quality of fresh commodities and minimise oxidative processes, including browning in fresh-cut products. The objective of this study was to investigate the efficacy of diode laser treatment in enhancing the quality of celtuce slices during refrigerated storage at 4 °C. The celtuce slices were subjected to a 660 or 450 nm diode laser for 5 min and then stored for 10 d. Both laser treatments hindered the progression of weight loss and firmness increase in the celtuce slices. The use of a 450 nm diode laser effectively prevented the development of browning and preserved the surface colour by inhibiting the increase in a* and overall colour difference values, as compared to other treatments, during storage for 10 d. The diode laser treatment suppressed the increase in oxidative stress by lowering the levels of MDA, H2O2, and O-2 while retaining a high level of DPPH scavenging activity, AsA, and antioxdant enzyme activities, including SOD, CAT, APX, and GR, in comparison to the untreated slices. The treatment enhanced chlorophylls content due to the up-regulation of LsHEMA1 gene and down-regulation of LsNYC1 gene. The treatment also inhibited factors involving enzymatic browning reaction by suppressing PAL activity, total phenols content, PPO activity and LsPPO gene expression. These suggest that the blue diode laser exposure at 450 nm for 5 min is an effective approach hindering oxidative stress and discoloration of celtuce slices during storage.

Spermidine augments salt stress resilience in rice roots potentially by enhancing OsbZIP73’s RNA binding capacity

BackgroundRice is a staple crop for over half of the global population, but soil salinization poses a significant threat to its production. As a type of polyamine, spermidine (Spd) has been shown to reduce stress-induced damage in plants, but its specific role and mechanism in protecting rice roots under salt stress require further investigation.ResultsThis study suggested spermidine (Spd) mitigates salt stress on rice root growth by enhancing antioxidant enzyme activity and reducing peroxide levels. Transcriptomic analysis showed that salt stress caused 333 genes to be upregulated and 1,765 to be downregulated. However, adding Spd during salt treatment significantly altered this pattern: 2,298 genes were upregulated and 844 were downregulated, which indicated Spd reverses some transcriptional changes caused by salt stress. KEGG pathway analysis suggested that Spd influenced key signaling pathways, including MAPK signaling, plant hormone signal transduction, and phenylalanine metabolism. Additionally, the bZIP transcription factor OsbZIP73 was upregulated after Spd treatment, which is confirmed by Western blot. Further insights into the interaction between OsbZIP73 and Spd were gained through fluorescence polarization experiments, showing that Spd enhances protein OsbZIP73’s affinity for RNA. Functional enrichment analyses revealed that OsPYL1, OsSPARK1, and various SAUR family genes involved in Spd-affected pathways. The presence of G/A/C-box elements in these genes suggests they are potential targets for OsbZIP73.ConclusionsOur findings suggest a strategy of using spermidine as a chemical alleviator for salt stress and provide insights into the regulatory function of OsbZIP73 in mitigating salt stress in rice roots.

Heat-stress memory enhances the acclimation of a migratory insect pest to global warming.

In the face of rising global temperatures, the mechanisms behind an organism's ability to acclimate to heat stress remain enigmatic. The rice leaf folder, Cnaphalocrocis medinalis, traditionally viewed as temperature-sensitive, paradoxically exhibits robust larval acclimation to heat stress. This study used the heat-acclimated strain HA39, developed through multigenerational exposure to 39°C during the larval stage, and the unacclimated strain HA27 reared at 27°C to unravel the transgenerational effects of heat acclimation and its regulatory mechanisms. Heat acclimation for larvae incurred a fitness cost in pupae when exposed to high temperature, yet a significant transgenerational effect surfaced, revealing heightened fitness benefit in pupae from HA39, even without additional heat exposure during larval recovery at 27°C. This transgenerational effect exhibited a short-term memory, diminishing after two recovery generations. Moreover, the effect correlated with increased superoxide dismutase (SOD) enzyme activity and expression levels of oxidoreductase genes, representing physiological and molecular foundations of heat acclimation. Heat-acclimated larvae displayed elevated DNA methylation levels, while pupae from HA39, in recovery generations, exhibited decreased methylation indicated by the upregulation of a demethylase gene and downregulation of two methyltransferase genes at high temperatures. In summary, heat acclimation induces DNA methylation, orchestrating heat-stress memory and influencing the expression levels of oxidoreductase genes and SOD activity. Heat-stress memory enhances the acclimation of the migratory insect pest to global warming.

Effects of ammonia nitrogen stress on the physiological, biochemical, and metabolic levels of the gill tissue of juvenile four-finger threadfin (Eleutheronema tetradactylum)

In this study, the impact of ammonia nitrogen stress on juvenile four-finger threadfin in pond culture was examined. The 96-hour median lethal concentration (LC50-96h) and safe concentration of ammonia nitrogen were assessed in juveniles with a body weight of 7.4 ± 0.6 g using ecotoxicological methods. The study design included a stress group exposed to LC50-96h levels of ammonia nitrogen and a control group without ammonia nitrogen exposure. To examine the physiological, biochemical, and metabolic effects of ammonia nitrogen on gill tissue, gill tissue samples were collected after 12, 24, 48, and 96 h of stress, with a resumption of treatment after 48 h. Compared to the control group, ammonia nitrogen adversely affected juvenile four-finger threadfin, with LC50-96h and safe concentration values of 20.70 mg/L and 2.07 mg/L, respectively. Exposure to ammonia nitrogen resulted in substantial gill damage, including fusion of lamellae, epithelial cell loss, and proliferation of chlorine-secreting cells. This tissue damage persisted even after a 48-h recovery period. Ammonia nitrogen stress triggered an increase in antioxidant enzyme activity (superoxide dismutase, catalase, and glutathione peroxidase) and malondialdehyde levels in gills, indicating oxidative stress from 12 h onwards. Although enzyme activity decreased over time, oxidative stress persisted even after recovery, suggesting an ongoing need for antioxidant defense. Metabolomics analysis showed significant alterations in 423 metabolites under ammonia nitrogen stress. Key metabolites such as L-arginine, taurine, 20-hydroxyarachidonic acid, 11,12-dihydroxy-5Z, 8Z, and 14Z eicosotrienic acid followed an increasing trend; uridine, adenosine, L-glutathione, and thymidine 5′-triphosphate followed a decreasing trend. These changes reflect metabolic adaptations to stress. In enriched metabolic pathways, the main differential pathways are membrane transport, lipid metabolism, and amino acid metabolism. After 48 h, significant differences were observed in 396 metabolites compared to the control group. Notably, L-arginine, choline, and L-histidine increased, while linoleic acid, adenosine, and glutathione decreased. Amino acid and lipid metabolism pathways were key affected pathways. Under ammonia nitrogen stress, juvenile four-finger threadfin increased the synthesis of unsaturated and saturated fatty acids to cope with low temperatures and bolster immune function by consuming spermidine. This adaptation helps to clear peroxides generated during fatty acid synthesis, thereby protecting cells from oxidative damage. This study provides insights for pond aquaculture and breeding of ammonia nitrogen-tolerant fish strains.

Anticancer Effects of Vaccinium arctostaphylos L. through HOTAIR/miR-124/Notch1 Axis of Hepatocellular Carcinoma in Rat: A Biochemical, Molecular, Immunohistochemical, and Histopathological Approaches

Background and Purpose We investigated the effectiveness of Vaccinium arctostaphylos L. fruit extract (VAFE) in protecting hepatocytes against N-diethylnitrosamine (DEN)-related hepatocellular carcinoma (HCC) by exploring its impact on biochemical, molecular, and antioxidant pathways, as well as its role in regulating the HOTAIR/miR-124/Notch1 axis pathway. Materials and Methods In the present study, 50 Wistar rats in 5 groups ( n = 10/group) of normal, HCC (80 mg/kg DEN), HCC rats receiving 200 and 400 mg/kg DEN + VAFE, and normal rats receiving 400 mg/kg VAFE were divided. The serum concentrations of liver function indices (bilirubin, total protein, albumin, alanine aminotransferase, aspartate aminotransferase, C-reactive protein, and alkaline phosphatase), inflammatory cytokines (interleukin (IL)-1β, IL-10, tumor necrosis factor-α, and IL-6) and oxidants parameters (catalase, superoxide dismutase, and glutathione peroxidase enzyme activity and nitric oxide levels) were measured. Liver tissue HOTAIR, miR-124, Notch1, and Jagged1 genes and proteins were measured. p53-positive cells of liver hepatocytes were evaluated by immunohistochemical technique. Results DEN induced significant changes in body and liver weight, serum liver enzymes, antioxidant levels, inflammatory markers, and HOTAIR/miR-124/Notch1 axis genes/proteins expression related to liver pathways. VAFE demonstrated dose-dependent effects in countering these changes, significantly improving weight, liver health, antioxidant capacity, and inflammatory responses, especially at 400 mg/kg. The histopathological evaluation showed improvements in liver tissue structure with VAFE treatment. Conclusion Overall, our study demonstrates the administration of VAFE can anticancer effects of DEN-induced HCC.

The Impact of Lighting Treatments on the Biosynthesis of Phenolic Acids in Black Wheat Seedlings.

Light, as a crucial environmental determinant, profoundly influences the synthesis of secondary metabolites in plant metabolism. This study investigated the impacts of the red light combined with ultraviolet-A (UV-A) and ultraviolet-B (UV-B) treatments on phenolic acid biosynthesis in black wheat seedlings. The results demonstrate that the red light combined with UV-A and UV-B treatments significantly enhanced the levels of phenolic acids in black wheat seedlings, at 220.4 μg/seedling and 241.5 μg/seedling, respectively. The content of bound phenolic acids in black wheat seedlings increased by 36.0% under the UV-B treatment. The application of the UV-A/UV-B treatments markedly enhanced the activities of phenylalanine ammonia-lyase, 4-coumarate CoA ligase, and cinnamate 4-hydroxylase in black wheat seedlings while also promoting the expression levels of genes related to phenolic acid synthesis. The expression levels of fructose-1,6-bisphosphate aldolase and NADP-malic enzyme related to photosynthesis were significantly upregulated. This resulted in an augmentation in the chlorophyll content, thereby enhancing photosynthesis in black wheat seedlings. Nevertheless, the UV-A and UV-B treatments also had a significant constraining effect on the growth and development of black wheat seedlings. In addition, the UV-A and UV-B treatments increased the activity and gene expression levels of antioxidant enzymes while significantly increasing the contents of total flavonoids and anthocyanins, activating the antioxidant system. The findings reveal that light-source radiation serves as an effective method for promoting the biosynthesis of phenolic acids in black wheat seedlings.

Silibinin-loaded Nanostructured Lipid Carriers (NLCs) Ameliorated Lead-induced Acute Nephrotoxicity in Male Rats.

As a toxic heavy metal, lead (Pb) is well known for impairment of renal function due to oxidative injuries. In contrast, the antioxidant activity of silibinin has been approved. Given the role of silibinin antioxidant activity, the present study investigated the effectiveness of silibinin-loaded nanostructured lipid carriers (Sili-NLCs) against Pb-induced acute nephrotoxicity in rats. The emulsification-solvent evaporation method was applied to prepare Sili-NLCs. Sixty male Wistar rats were divided into ten separate groups. Pb (20 mg/kg/day, i.p.) was applied to induce nephrotoxicity and in the treatment groups animals received the same concentration of silibinin and Sili-NLCs (25, 50, and 100 mg/kg/day, p.o.) for five days. After sacrificing rats, kidney tissue samples were collected to assess the oxidative stress parameters, including lipid peroxidation (LPO), nitric oxide (NO), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity. Also, histopathological examination using Hematoxylin-Eosin (H&E) was studied. Not only did Pb injection significantly increase the renal levels of LPO and NO, but also decreased the levels of antioxidant enzyme activity. On the other hand, Sili-NLCs were more effective than silibinin in decreasing renal oxidative damage by increasing the antioxidant defense system. Moreover, the histopathological examination correlated well with biochemical findings. Our data suggested that Sili-NLCs are potentially superior to pure silibinin for attenuating Pb-induced acute nephrotoxicity.

Cellular and subcellular effects of chronic low-dose Lambda-cyhalothrin pesticide exposure modulated by medicinal plant methanol extract in rat

The extensive use of Lambda-cyhalothrin (LCT) has been associated with the various toxicities that non-target organisms can undergo including mammals. However, the mechanism of LCT-induced cytotoxicity in animal brain cells is still elusive, particularly in brain regions, notably the hippocampus, an area directly involved in cognitive function. This study aimed to investigate the neurotoxic effects in the rat hippocampus chronically exposed to LCT (0.18 mg/kg and 0.36 mg/kg), and the neuroprotective potential of Melissa officinalis L methanol extract (MOE) (200 mg/kg) against this toxicity. After experimental period (90 days), the redox status, the functional and structural integrity of the hippocampus mitochondria as well as the apoptotic signaling pathway were evaluated. The current findings suggest that LCT induces an imbalance of mitochondrial redox status characterized by, on one side, an increase of stress markers such as protein carbonyls (PCO), malondialdehyde (MDA), and hydrogen peroxide (H2O2) levels; and on the other side, a decline in the potential of antioxidant systems, namely the level of mitochondrial enzymatic activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) and glutathione (GSH).This study also showed an increase in mitochondrial permeability, along with mitochondrial edema and considerable decrease in its O2 consumption. Moreover, the same results recorded an increase in caspase-3 and cytosolic cytochrome-c. Conversely, this study proved that all these toxic aspects induced by LCT were significantly mitigated when the administration of this synthetic pyrethroid was associated with MOE. Taken together, data of this study shed light on mitochondrial damage and apoptosis stimulation under the toxic effect of LCT and suggests that MOE is endowed with potent neuroprotective effects, possibly via its antioxidant and antiapoptotic properties.

Anoectochilus roxburghii Extract Extends the Lifespan of Caenorhabditis elegans through Activating the daf-16/FoxO Pathway.

As a significant global issue, aging is prompting people's interest in the potential anti-aging properties of Anoectochilus roxburghii (A. roxburghii), a plant traditionally utilized in various Asian countries for its purported benefits in treating diabetes and combating aging. However, the specific anti-aging components and mechanisms of A. roxburghii remain unclear. This study aims to investigate the anti-aging effects and mechanisms of A. roxburghii extract E (ARE). Caenorhabditis elegans (C. elegans) were exposed to media containing different concentrations of ARE whose superior in vitro radical scavenging capacity was thus identified. Lifespan assays, stress resistance tests, and RT-qPCR analyses were conducted to evaluate anti-aging efficacy, reactive oxygen species (ROS) levels, antioxidant enzyme activity, and daf-16, sod-3, and gst-4 levels. Additionally, transcriptomic and metabolomic analyses were performed to elucidate the potential anti-aging mechanisms of ARE. Fluorescence protein assays and gene knockout experiments were employed to validate the impacts of ARE on anti-aging mechanisms. Our results revealed that ARE not only prolonged the lifespan of C. elegans but also mitigated ROS and lipofuscin accumulation, and boosted resistance to UV and heat stress. Furthermore, ARE modulated the expression of pivotal anti-aging genes including daf-16, sod-3, and gst-4, facilitating the nuclear translocation of DAF-16. Significantly, ARE failed to extend the lifespan of daf-16-deficient C. elegans (CF1038), indicating its dependency on the daf-16/FoxO signaling pathway. These results underscored the effectiveness of ARE as a natural agent for enhancing longevity and stress resilience to C. elegans, potentially to human.

Assessing and Quantifying the Carbon, Nitrogen, and Enzyme Dynamics Effects of Inter-row Cover Cropping on Soils and Apple Tree Development in Orchards

Cover crops between rows in orchards can improve the development of soil resources and increase agricultural productivity. However, there have been few reports of cover crops that can act as a “green manure” in apple orchards across arid and semiarid zones. This study investigated the effects of planting interrow vegetation on soil properties and apple tree performance during a 32-month experiment. There were six treatments: clean cultivation as a control; natural grass planting; planting with ryegrass; planting with alfalfa; planting with tall fescue; and planting with villous wild pea cover crops. The treatments primarily affected the 0- to 20-cm surface soil layer. Soil carbon, nitrogen, and enzyme levels initially decreased (during the first 12–24 months); then, they increased (24–32 months). The cover crops significantly increased nutrient contents (soluble organic carbon, microbial carbon and nitrogen, alkaline dissolved nitrogen, nitrate nitrogen, and ammonium nitrogen) in the 0- to 20-cm soil layer by more than 19.6% and increased the related enzyme activities by more than 25.2%. The alfalfa and wild pea alleys had a stronger effect on the soil environment than the control, natural grass, ryegrass, and tall fescue alley treatments; however, after 32 months, the alfalfa treatment inhibited fruit tree growth and development. This was unexpected because alfalfa seemed to have a positive effect on soil fertility characteristics. Under local ecological conditions, villous wild pea had the greatest effect on apple orchard productivity and significantly increased short branching by 15.9%, fruit weight per fruit by 12.6%, yield per plant by 8.6%, and soluble sugar content by 10.5% compared with clean cultivation. The correlation analysis showed that there were significant or highly significant positive correlations between fruit tree performance and soil carbon, nitrogen, and enzyme activity levels as the soil layer depth increased. Therefore, under local ecological conditions, cover crops have a greater effect on orchard surface soil fertility than on deeper soils, and intercropping with villous wild pea potentially produces the greatest improvement in apple orchard productivity.

Pharmacological Activities and Molecular Mechanisms of Sinapic Acid in Neurological Disorders.

Sinapic acid (SA) is a phenylpropanoid derivative found in various natural sources that exhibits remarkable versatile properties, including antioxidant, anti-inflammatory, and metal-chelating capabilities, establishing itself as a promising candidate for the prevention and treatment of conditions affecting the central nervous system, such as Alzheimer's disease (AD), Parkinson's disease (PD), ischemic stroke, and other neurological disorders. These effects also include neuroprotection in epilepsy models, as evidenced by a reduction in seizure-like behavior, cell death in specific hippocampal regions, and lowered neuroinflammatory markers. In AD, SA treatment enhances memory, reverses cognitive deficits, and attenuates astrocyte activation. SA also has positive effects on cognition by improving memory and lowering oxidative stress. This is shown by lower levels of oxidative stress markers, higher levels of antioxidant enzyme activity, and better memory retention. Additionally, in ischemic stroke and PD models, SA provides microglial protection and exerts anti-inflammatory effects. This review emphasizes SA's multifaceted neuroprotective properties and its potential role in the prevention and treatment of various brain disorders. Despite the need for further research to fully understand its mechanisms of action and clinical applicability, SA stands out as a valuable bioactive compound in the ongoing quest to combat neurodegenerative diseases and enhance the quality of life for affected individuals.

The cultivable gut bacteria Enterococcus mundtii promotes early-instar larval growth of Conogethes punctiferalis via enhancing digestive enzyme activity.

Gut bacteria are crucial in influencing insect development and even phenotypic plasticity. The yellow peach moth Conogethes punctiferalis, as a significant borer pest, has been the subject of limited reports regarding the structural and diversification changes in its gut microbiota during feeding, and their potential impacts on the growth and development of the host insects. This study, employing 16S rRNA sequencing, demonstrates distinct shifts in the larvae gut microbiome of C. punctiferalis between different feeding stages, highlighting a pronounced diversity in the early-instar with Enterococcus as a predominant genus in laboratory populations. Through in vitro cultivation and sequencing, three bacterial strains - Micrococcus sp., Brevibacterium sp. and Enterococcus mundtii - were isolated and characterized. Bioassays revealed that E. mundtii-infused corn significantly boosts early-instar larval growth, enhancing both body length and weight. Quantitative PCR and spectrophotometry confirmed a higher abundance of E. mundtii in younger larvae, correlating with increased digestive enzyme activity and total protein levels. This study reveals the heightened gut microbiota diversity in early instars of C. punctiferalis larvae, highlighting that Enterococcus represent a predominant bacteria in laboratory populations. In vitro cultivation and bioassays unequivocally demonstrate the significant role of the cultivable gut bacteria E. mundtii in promoting the growth of early-instar larva. These findings provide a solid theoretical foundation for advancing the comprehension of the intricate interactions between gut microbiota and insect hosts, as well as for the development of eco-friendly pest control technologies based on targeted manipulation of insect gut microbial communities. © 2024 Society of Chemical Industry.

Exploring the protective role of Bacillus velezensis BV1704–Y in zebrafish health and disease resistance against Aeromonas hydrophila infection

Bacillus genus, particularly Bacillus velezensis, is increasingly considered as viable alternatives to antibiotics in aquaculture due to their safety and probiotic potential. However, the specific mechanisms through which probiotic B. velezensis confers protection against Aeromonas hydrophila infection in fish remain poorly understood. This study delved into the multifaceted impacts of B. velezensis BV1704–Y on diverse facets of zebrafish health, including gut barrier function, immune response, oxidative stress, gut environment, microbiome composition, and disease resistance. Our findings demonstrate that supplementation with B. velezensis BV1704–Y significantly alleviated symptoms and reduced mortality in zebrafish infected with A. hydrophila.Furthermore, a notable reduction in the expression of pivotal immune-related genes, such as IL-1β, IL6, and TNF-α, was evident in the gut and head kidney of zebrafish upon infection. Moreover, B. velezensis BV1704–Y supplementation resulted in elevated activity levels of essential antioxidant enzymes, including SOD, CAT, and GSH, in gut tissue. Notably, B. velezensis BV1704–Y positively modulated the structure and function of the intestinal microbiome, potentially enhancing immune response and resilience in zebrafish. Specifically, supplementation with B. velezensis BV1704–Y promoted the relative abundance of beneficial bacteria, such as Cetobacterium, which showed a noteworthy negative correlation with the expression of pro-inflammatory genes and a positive correlation with gut barrier-related genes. Altogether, our study suggests that B. velezensis BV1704–Y holds promise as an effective probiotic for protecting zebrafish against A. hydrophila infection, offering potential benefits for the aquaculture industry.

A study on membrane enzyme Na+-K+-ATPase in lindane exposed fish, Channa punctatus

Na+-K+-ATPase is a membrane bound enzyme responsible for the transport of ions through the membrane and immediate release of energy. This enzyme is known to be an early target for oxygen radical induced damage to intact cell. Exposure of C. punctatus to subacute concentrations of lindane for 96 h caused significant reduction in the activities of Na+-K+-ATPase in all the tissues of the fish tested; brain being maximally affected and the heart being least affected organ at the highest concentration of lindane (0.1 mg/L). The effect of pesticide was concentration dependent. The percent decrease in the activity of Na+-K+-ATPase in brain, gills, heart, kidney, liver and muscle was found to be 36.7, 23.4, 19.2, 29, 22.9 and 29.7, respectively. The order of level of enzyme activity recorded was as following: liver > gills > kidney > brain > muscle > heart in the control.

Inhibition of JNK transcription via the Nrf2/Keap1a pathway to resist microcystin-induced oxidative stress and apoptosis in freshwater mussels Cristaria plicata

With global warming and increasing eutrophication of water bodies, a variety of algal toxins, including microcystin (MC), released into water by cyanobacterial blooms pose a serious threat to the survival of aquatic organisms. To investigate the mechanism of the Nrf2/Keap1a pathway on resisting MC-induced oxidative stress and apoptosis in Cristata plicata, we cloned the full-length cDNA of CpBcl-2. The cDNA full-length of CpBcl-2 was 760 bp, encoded a 177 amino acid peptide, and contained a highly conserved Bcl-2-like superfamily domain. MC stimulation increased the expression and activity levels of related antioxidant enzymes. After CpNrf2 knockdown, the transcription levels of NAD(P)H quinone redox Enzyme-1 (NQO1) and related antioxidant enzymes activity in the gills and kidney of C. plicata were significantly down-regulated upon MC stress, but that was significantly upregulated after knockdown of CpKeap1a. Additionally, Upon MC stress, the mRNA levels of CpBcl-2 were increased in the gills and kidney after knockdown of CpNrf2 at 24 h, and that of CpBcl-2 were decreased at 72 and 96 h in the CpKeap1a-siRNA+MC group. Moreover, MC stimulation significantly inhibited CpJNK expression in the gills and kidney, but which regulated the Nrf2/Keap1a pathway in C. plicata. However, the JNK inhibitor SP600125 promoted the expression of CpNrf2 and related enzymes with antioxidant response element (ARE-driven enzyme) in the gills and kidney. Then, we speculated that CpKeap1a was a negative regulator of CpNrf2, and C. plicata resisted MC-induced oxidative damage and apoptosis by inhibiting JNK transcription via the Nrf2/Keap1a pathway.

High levels of mitochondrial dynamics, autophagy, and apoptosis contribute to stable testicular status in hibernating Daurian ground squirrels

Daurian ground squirrels (Spermophilus dauricus) experience various stress states during winter hibernation, but the impact on testicular function remains unclear. This study focused on the effects of changes in testicular autophagy, apoptosis, and mitochondrial homeostasis signaling pathways at various stages on the testes of Daurian ground squirrels. Results indicated that: (1) During winter hibernation, there was a significant increase in seminiferous tubule diameter and seminiferous epithelium thickness compared to summer. Spermatogonia number and testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels were higher during inter-bout arousal, suggesting that the testes remained stable during hibernation. (2) An increased number of mitochondria with intact morphology were observed during hibernation, indicating that mitochondrial homeostasis may contribute to testicular stability. (3) DNA fragmentation was evident in the testes during the hibernation and inter-bout arousal stages, with the highest level of caspase3 enzyme activity detected during inter-bout arousal, together with elevated levels of Bax/Bcl-2 and Lc3 II/Lc3 I, indicating an up-regulation of apoptosis and autophagy signaling pathways during hibernation. (4) The abundance of DRP1, MFF, OPA1, and MFN2 proteins was increased, suggesting an up-regulation of mitochondrial dynamics-related pathways. Overall, testicular autophagy, apoptosis, and mitochondrial homeostasis-related signaling pathways were notably active in the extreme winter environment. The well-maintained mitochondrial morphology may favor the production of reproductive hormones and support stable testicular morphology.

Investigating process parameters to enhance (hemi)cellulolytic enzymes activity produced by Trichoderma reesei RUT-C30 using deoiled oil palm mesocarp fiber in solid-state fermentation

This study investigates the synthesis of (hemi)cellulolytic enzymes, including endoglucanase (CMCase), xylanase, and β-glucosidase, employing Trichoderma reesei RUT-C30 and deoiled oil palm mesocarp fiber (OPMF) through solid-state fermentation (SSF). The objective was to determine the optimal process conditions for achieving high enzyme activities through a one-factor-at-a-time approach. The study primarily focused on the impact of the solid-to-liquid ratio, incubation period, initial pH, and temperature on enzyme activity. The effects of OPMF pretreatment, particularly deoiling and fortification, were explored. This approach significantly improved enzyme activity levels compared to the initial conditions, with CMCase increasing by 111.6 %, xylanase by 665.2 %, and β-Glucosidase by 1678.1 %. Xylanase and β-glucosidase activities, peaking at 1346.75 and 9.89 IU per gram dry substrate (GDS), respectively, under optimized conditions (1:4 ratio, pH 7.5, 20 °C, 9-day incubation). With lower moisture levels, CMCase reached its maximum activity of 227.84 IU/GDS. The study highlights how important it is for agro-industrial byproducts to support environmentally sustainable practices in the palm oil industry. It also emphasizes how differently each enzyme reacts to changes in process parameters.

Methane-rich saline ameliorates depressive-like behaviors during chronic unpredictable mild stress (CUMS).

Depression, considered the most prevalent neuropsychiatric disorder, is multifactorial and complex. Oxidative stress and inflammation significantly contribute to its etiology. Conversely, methane, a novel therapeutic gas, has demonstrated efficacy in enhancing tissue resilience against ischemic injuries and inflammation. In this study, we investigated the effect of methane-rich saline (MRS) on depression using the chronic unpredictable mild stress (CUMS) model. Depressed rats received MRS treatment, and depression-like behaviors and cognitive function were assessed through sucrose preference, open field, forced swimming, and Morris water maze tests. Additionally, we measured serum corticosterone levels, antioxidant enzyme activity, hippocampal malondialdehyde (MDA), and TNFα levels, and investigated histological changes in the hippocampus. Our findings revealed that MRS significantly ameliorated Depressive-like behaviors and cognitive impairment. Furthermore, MRS administration regulated serum corticosterone levels and also MRS reduced hippocampal lipid peroxidation, TNFα, and hippocampus tissue damage. MRS likely exerts its effects by reducing oxidative stress and inflammatory factors and modulating the function of the hypothalamus-pituitary-adrenal (HPA) axis. These results demonstrate the protective effects of MRS on the hippocampus in CUMS animals.