Lower Catalase Research Articles

Exposure of Apis mellifera (Hymenoptera: Apidae) colonies to imidacloprid impairs larval development, promotes oxidative stress in pupae, and induces changes in the midgut of adult bees

Bees are essential pollinators that contribute to maintaining biodiversity and increasing agricultural production. However, by foraging on agricultural crops, bees may become contaminated with compounds used for pest control. In this study, we exposed bee (Apis mellifera L.) colonies to the insecticide imidacloprid (IMD) under field conditions to assess the occurrence of oxidative stress in larvae and pupae and investigate morphological changes in the fat body and midgut of larvae and midgut of adult bees. The apiary area was divided into three groups: control, commercial formulation containing IMD (Evidence® 700WG) (IMDCF), and IMD active ingredient (Sigma–Aldrich) (IMDAI). Treatment groups were fed syrup containing 1 µg L−1 IMD, whereas the control group was fed syrup only. Compared with the control, larvae exposed to IMDCF or IMDAI for 42 days exhibited morphological changes in the external body, midgut, and fat body. The midgut of adult bees contaminated with IMDCF showed only structural remnants of the peritrophic membrane and absence of regenerative cell nests. Oxidative stress analyses revealed that IMDCF-exposed larvae had higher nitrite and carbonylated protein contents and lower catalase and superoxide dismutase activity than control individuals. In pupae, IMDAI decreased catalase activity while increasing superoxide dismutase activity. These findings indicate that IMD has the potential to significantly impact the development of bees and their colonies by disrupting vital organs responsible for normal physiological functioning and overall activities of individuals. Oxidative stress, which was detected at different stages of bee development, may induce lipid, protein, and DNA oxidation, leading to cell death.Graphical

Genotoxicity and oxidative stress assessment among farmers occupationally exposed to pesticides in El-Behira Governorate, Egypt

ABSTRACT Background Recently, pesticide usage has rapidly increased worldwide and consequently, there is a great worry about their adverse health effects. In literature, there is paucity of research regarding the relationship between occupational pesticide exposure and genotoxicity. The current study aimed to detect sociodemographic and occupational characteristics of the participants and to assess biomarkers of genotoxicity and oxidative stress and reveal their association with exposure to pesticides. Methods A comparative cross-sectional approach was carried out at a randomly selected village where 58 farmers exposed to pesticides were compared with another 58 individuals not exposed to pesticides. Participants were interviewed; blood samples were withdrawn for measuring the following: deoxyribonucleic acid (DNA) fragmentation percentage, serum thiobarbituric acid reactive substances (TBARS) level, serum activity levels of glutathione reductase (GR), catalase (CAT), superoxide dismutase (SOD), and butyrylcholinesterase (BChE) enzymes. Results Farmers had significantly higher levels of DNA fragmentation, TBARS, and SOD [8.07 ± 2.38, 1.42 (0.79), and 350.09 (30.03), respectively] than the comparison group [4.41 ± 1.35, 0.37 (0.72), and 281.25 (130.37), respectively]; While they had a lower GR, CAT, and BChE levels [14.53 ± 8.53, 21.7 (41.04), and 2707.77 ± 651.24, respectively] than the comparison group [24.92 ± 9.44, 37.8 (41.72), and 5694.3 ± 1175.76, respectively]. Exposure to pesticides was found to be independently associated with an increase in the percentage of DNA fragmentation by 3.146%; an increase in TBARS level by 0.717 nmol/dL; an increase in the SOD enzyme activity level by 72.614 IU/mL and a decrease in the GR enzyme activity level by 10.094 IU/mL. Conclusion Pesticide exposure is associated with genotoxicity and oxidative stress.

Carotenoids from Halophilic Archaea: A Novel Approach to Improve Egg Quality and Cecal Microbiota in Laying Hens.

Carotenoids from different sources have different structures and functions, and their dietary components benefit the health of various organisms. The effects of halophilic Archaea-derived C50 carotenoids on poultry egg quality and gut microbiota remain largely unexplored. In this study, we isolated a carotenoid-secreting strain of Halalkalicoccus paucihalophilus, TRM89021, from the Pamir Plateau. We characterized the carotenoid pigments produced by this strain; the major components were bacterioruberin and its derivatives. The effects of these carotenoids on the egg quality and cecal microbiota composition of hens were investigated. Compared to the basal diet group (BDG), supplementation with carotenoids in the carotenoids-supplemented diet group (CDG) resulted in significantly lower a* and b* scores at week 5 and lower b* scores and Haugh units at week 2, while egg strength and weight were higher. CDG also showed increased yolk antioxidant capacity, higher glutathione peroxidase levels, and significantly lower catalase levels (p < 0.05). Plasma analysis revealed elevated total bilirubin and aspartate aminotransferase levels, along with reduced inorganic phosphorus levels in the CDG (p < 0.05). No significant differences in cecal microbiota diversity were observed between the groups at any taxonomic level. This result suggests that halophilic archaea-derived carotenoids have the potential to be used as natural feed supplements to improve egg quality. Our study provides a theoretical basis for applying archaea-derived carotenoids in poultry diets.

Impact of accelerated aging on seed quality, seed coat physical structure and antioxidant enzyme activity of Maize (Zea mays L.).

Aging induces many deteriorative changes to seeds during storage like protein degradation, enzyme inactivation and loss of membrane integrity. In this study, we investigate the impact of accelerated aging on seed quality, seed coat physical structure and antioxidant enzyme activity of maize. Three genotypes African Tall, MAH 14-5 and a local landrace were selected and artificially aged for 96 and 120 h. The aging process led to a decrease in germination, vigour, and total dehydrogenase in seeds, while the electrical conductivity of seed leachates increased, indicating a decline in seed quality. Additionally, there was a variation in the microsculpture pattern of seed coats between genotypes. There was an accumulation of damage on the seed coat surface as the seeds aged and higher damage occurred in African Tall followed by MAH 14-5 and local landrace. Higher catalase, superoxide dismutase, peroxidase and polyphenol oxidase activity were reported in the seed coat of Local landrace and MAH 14-5 that resisted aging and deterioration while, lower catalase, superoxide dismutase, peroxidase and polyphenol oxidase activity was reported in African Tall seed coat that deteriorated during aging. Decrease antioxidant activity in aged seeds might be a possible cause of seed deterioration due to the accumulation of free radicals. Thus, these results clearly show the influence of seed coat structure and antioxidant activity on seed quality during aging.

Palm and Interesterified palm oil-enhanced brown fat whitening contributes to metabolic dysfunction in C57BL/6J mice

Palm oil is widely used in the food industry owing to its high stability and versatility. The interesterified version has been used as an alternative to oils rich in trans fatty acids. However, the health effects of these vegetable oils are not yet fully understood. We hypothesized that the consumption of palm oil (non-interesterified and interesterified), even without excessive amounts of energy and lipids in the diet, could lead to morphofunctional changes in brown adipose tissue (BAT). To this end, male C57BL/6J mice were divided into three dietary groups (n = 10 each): soybean oil (SO), palm oil (PO), and interesterified palm oil (IPO) for 10 weeks. The PO and IPO groups had significant increases in the visceral fat mass and interscapular BAT (iBAT) lipid content. In iBAT, the PO and IPO groups showed lower mRNA expression of Ucp1, Adrb3, and Pgc1a, while the PO also showed lower mRNA levels of Ppara and Ampk, and the IPO showed lower Prdm16 expression. Moreover, PO had higher Il6 expression and lower catalase activity, while the IPO showed an upregulated Tnfa expression and lower catalase activity, but higher antioxidant activity of the glutathione peroxidase (GPx) enzyme. The consumption of PO and IPO had negative effects on weight and body fat, including the impairment of iBAT function. Our findings give rise to apprehensions regarding the safety and consequences of consuming palm and interesterified palm oils for energy metabolism.

Characterization of the Peroxisomal Proteome and Redox Balance in Human Prostate Cancer Cell Lines.

Prostate cancer (PCa) is associated with disruptions in cellular redox balance. Given the intricate role of peroxisomes in redox metabolism, we conducted comprehensive proteomics analyses to compare peroxisomal and redox protein profiles between benign (RWPE-1) and malignant (22Rv1, LNCaP, and PC3) prostate cell lines. Our analyses revealed significant enrichment of the "peroxisome" pathway among proteins notably upregulated in androgen receptor (AR)-positive cell lines. In addition, catalase (CAT) activity was consistently higher in these malignant cell lines compared to RWPE-1, which contrasts with previous studies reporting lower CAT levels and increased H2O2 levels in PCa tissues compared to adjacent normal tissues. To mimic this clinical scenario, we used RNA interference to knock down CAT expression. Our results show that reduced CAT levels enhanced 22Rv1 and LNCaP cell proliferation. R1881-induced activation of AR, a key driver of PCa, increased expression of the H2O2-producing peroxisomal β-oxidation enzymes acyl-coenzyme A oxidase 1 and 3, reduced CAT expression and activity, and elevated peroxisomal H2O2 levels. Considering these changes and other antioxidant enzyme profile alterations, we propose that enhanced AR activity in PCa reduces CAT function, leading to increased peroxisomal H2O2 levels that trigger adaptive stress responses to promote cell survival, growth, and proliferation.

Impacts of Breed, Production System and Feeding Type on Nutritional, Organoleptic Characteristics and Oxidative Status on Beef Cattle in Sub-Saharan Africa: A Cross-Sectional Study

Purpose: The aim of this study was to investigate the influence of breed, production system, and feeding type on meat quality, evaluating organoleptic and physicochemical traits and antioxidant status across selected local cattle breeds. Materials and Methods: The study was carried out on sirloin and blood samples taken in slaughterhouses from the hot carcass of male cattle, divided according to breed, production system and type of feed. The nutritional, organoleptic characteristics and oxidative status was assessed. Findings: The results revealed that meat from Goudali breed raised in a sedentary system exhibited significantly lower tenderness (p&lt;.) and higher lipid (p&lt;.) and protein (p&lt;.) contents. Additionally, the meat displayed notably lower pH (p=.), reduced cortisol (p&lt;.), and lower catalase (p&lt;.), TAC (p&lt;.), and FRAP (p=.) activities. Consumers preferred the meat of the White Fulani breed due to its color (p&lt;.). In transhumant system, the meat was richer in dry matter (p=.), lipids (p&lt;.), and fibres (p=.), while the sedentary system resulted in more tender (p=.) and red-dark colored meat (p&lt;.), which consumers favored. Meat from cows under commercial feed were preferred by consumers (p&lt;.) compared to grass-fed cows, exhibiting significantly higher lipid (p&lt;.) and protein (p&lt;.) levels as well as intense color (p=.). However, meat from grass-fed cows had significantly higher fibre content (p&lt;.), tenderness (p&lt;.), better taste (p=.), juiciness (p=.), and higher catalase (p=.) and TAC (p&lt;.) activities. Implications to Theory, Practice and Policy: These findings underscore the importance of considering breed, production system, and feeding type when conserving, selecting, or improving beef breeds for both meat quantity and quality.

Effects of Adverse Life History on Oxidative Stress and Cytokine Concentration in Domestic Dogs

ABSTRACT Early-life stress has been well studied in humans and laboratory animals; however, the impacts of similar adversity on the welfare of domestic dogs has recently begun to be addressed. For example, associations between processes linked to mitochondrial function, such as oxidative stress (OS) and proinflammatory immune systems, have been under-researched. Yet, mitochondria are targets and mediators of stress pathologies. This study investigates the impact of early-life stress on OS and proinflammatory immune responses in shelter dogs compared to client-owned dogs. We measured OS markers, including total antioxidant capacity (TAC), lipid oxidative damage, catalase (CAT) activity, glutathione peroxidase (GPx) activity, and superoxide dismutase (SOD) concentration, as well as inflammatory cytokines IL-1β, IL-6, and TNF-α. Shelter dogs exhibited significantly higher lipid oxidative damage (p = 0.0265), lower CAT activity (p = 0.002), higher SOD concentration (p < 0.001), and increased IL-1β levels (p = 0.027) compared to client-owned dogs. Compared to client-owned dogs, shelter dogs showed increased OS and inflammation, suggesting higher susceptibility to zoonotic and chronic diseases.

Application of iron oxide nanoparticles improves growth and phytochemical constituents of in vitro cultured Carum copticum L.

Iron oxide nanoparticles (FeONPs) are widely used in various applications, such as biomedicine, environmental remediation, and agriculture. Moreover, FeONPs can affect the production of secondary metabolites in plants, which are compounds that have various biological and pharmacological activities. Therefore, in this study, the ajwain (Carum copticum L.) seeds were grown in MS medium containing different levels of FeONPs (0, 100, 200, and 400 mg l−1). After four weeks, the effects of FeONPs on growth, photosynthesis pigments, total phenolic, and anthocyanin content, activities of some antioxidant enzyme and secondary metabolites of ajwain) were investigated. The results showed that low levels of FeONPs (especially 200 mg l−1) increased fresh weight (231 %), total chlorophyll (49 %), total phenolics (259 %), anthocyanin content (110 %), as well as thymol (8 %) and γ-terpinene (16 %) content. Conversely, 400 mg l−1 FeONPs reduced root length (60 %) and fresh weight (64 %) was associated with a reduction in CAT activity, phenol (55 %), thymol (22 %), and γ-terpinene (18 %) content compared to ajwain treated with 200 mg l−1 FeONPs. This reduction was probably due to the increase in ROS caused by the low catalase enzyme activity and important essential oils compounds such as thymol and γ-terpinene. Thus, our results indicate that FeONPs at certain levels can be used as a new way for in vitro production of valuable essential oils and antioxidant compounds in ajwain.

Targeting calcium dependant/cAMP/PKA/CREB pathway and GABAergic transmission by drotaverine and hesperidin for amelioration of tardive dyskinesia

Antipsychotics, commonly used for anxiety and psychosis, are linked to severe side effects like fatal ventricular arrhythmias, sudden cardiac death, and movement disorders, limiting their therapeutic use. This research aimed to explore novel mechanisms to treat psychotic anxiety while minimizing these risks. Drotaverine activates the cAMP/PKA/CREB pathway, while Hesperidin inhibits dopaminergic hyperactivity. Using a reserpine-induced orofacial dyskinesia model, which mimics tardive dyskinesia linked to oxidative stress, reserpine (1 mg/kg, s.c) was administered for three days. Rats were pre-treated with drotaverine (8 mg/kg, p.o) and hesperidin (50 mg/kg, p.o) for five days. Statistical analysis via one-way ANOVA and Dunnett’s test showed that reserpine significantly increased vacuous chewing movements (VCMs), tongue protrusions (TPs), and reduced locomotion and exploration. Pre-treatment with drotaverine and hesperidin reduced VCMs and TPs. Reserpine-treated rats had lower catalase and higher lipid peroxidation (LPO) levels, indicators of oxidative stress, which were reversed by the drugs. Additionally, drotaverine improved cognition by modulating the cAMP/PKA/CREB pathway, and Hesperidin offered neuroprotection through GABAergic transmission. Both drugs, alone or in combination, demonstrate potential as alternative therapies for psychotic anxiety with neuroprotective benefits.

Effect of diets containing probiotic yeast Cystobasidium benthicum and fruit Cyrtocarpa edulis on growth and immune parameters of Nile tilapia (Oreochromisniloticus)

This study investigates Cystobasidium benthicum (Cb) probiotic yeast and Cyrtocarpa edulis (Ce) fruit dietary effects, single (0.5 %) or combined (Cb:Ce, 0.25:0.25 %), on growth performance, humoral immunity in serum and skin mucus, and intestinal morphology of Nile tilapia (Oreochromis niloticus) after 14 and 28 days. The Cb group presented the highest (P < 0.05) specific growth rate, weight gain, and absolute growth rate with respect to the control group. Immunological assays indicated that Cb, Ce and Cb:Ce groups increased serum nitric oxide concentration compared to the control group (P < 0.05). Cb and Cb:Ce groups showed the highest serum myeloperoxidase enzyme activity at day 14 and 28, respectively (P < 0.05); whereas, Cb:Ce group had the highest (P < 0.05) myeloperoxidase activity in skin mucus. The superoxide dismutase enzyme activity was unaffected. On day 28, Cb, Ce, and Cb:Ce groups showed higher and lower (P < 0.05) catalase enzyme activity in serum and skin mucus, respectively, compared with the control group. Only the Cb group had higher (P < 0.05) total protein concentration in serum (day 14) and skin mucus (day 14 and 28) with respect to the control group. The lysozyme activity in serum (day 28) and skin mucus (day 14) was higher (P < 0.05) in the Cb group compared to the control group. Only the skin mucus of Ce group showed bactericidal activity against Aeromonas dhakensis (P < 0.05). Histological studies indicated that Cb and Cb:Ce groups increased microvilli height, and Cb, Ce and Cb:Ce augmented goblet cell area at day 14 compared to the control group (P < 0.05). At day 28, microvilli height was higher in all groups and the number of intraepithelial leukocytes increased in Cb and Ce groups with respect to the control group (P < 0.05). The ex vivo assay revealed that A. dhakensis in leukocytes decreased cell viability similar to the control group (P < 0.05). A principal component analysis (PCA) confirmed the results. In conclusion, C. benthicum in the diet was the best supplement to improve the growth and immunity of Nile tilapia.

Effectiveness of setarud (IMOD™) in attenuating gentamicin-induced nephrotoxicity in male rats

BackgroundGentamicin (GEN) can have serious adverse effects including nephrotoxicity. Setarud (IMOD™) is a new herbal drug with beneficial immune effects, obtained by mixing Tanacetum vulgare (tansy), Rosa canina and Urtica dioica (nettle) extracts as well as selenium, flavonoids and carotenes. This novel study aims to evaluate the effectiveness of Setarud (IMOD™) in attenuating GEN-induced nephrotoxicity in male rats. Twenty-eight adult male Sprague Dawley rats (weighing 180–200 g) were randomly divided into four groups (7 rats in each group): Control, IMOD treated (20 mg/kg body weight), GEN treated (100 mg/kg body weight), and GEN + IMOD co-treated. Injections were done intraperitoneally for 12 days. Serum urea, creatinine (Cr), Cr clearance, malondialdehyde (MDA), reduced glutathione (GSH) level, and activities of antioxidant enzymes Peroxidase (POD), Catalase (CAT), and Glutathione peroxidase (GPx) were measured by the colorimetric method. Volume density of proximal convoluted tubule (PCT), tubular necrosis, tubular cast formation, and leukocytic infiltration were evaluated histopathologically.ResultsIn the GEN group, there were significantly higher serum urea, Cr, and MDA levels with lower Cr clearance, GSH levels, POD, GPx and CAT activities, and PCT volume density with presence of tubular necrosis compared to the control and IMOD groups (P < 0.05). Treatment with IMOD significantly reduced the levels of urea, Cr and MDA, and increased Cr clearance and the activities of POD and CAT enzymes (P < 0.05). No significant differences in the activity of GSH and GPx were reported in the GEN + IMOD co-treated group compared to the GEN group. Moreover, IMOD significantly ameliorated PCT volume density and renal lesions caused by GEN.ConclusionIMOD (20 mg/kg body weight) can attenuate GEN-induced nephrotoxicity in rats by inhibition of oxidative stress or increasing the normal activity of antioxidant enzymes. Further studies are recommended on the effects of different doses of IMOD.

Does the frequency of hunting dogs’ activity influence their oxidative stress status subsequent to endurance?

Oxidative stress is implied in various pathological conditions in both humans and animals, and recent studies have suggested its role in performance, recovery, immunity, and health. This study’s objective was to investigate whether the higher frequency of activity by hunting dogs influences the oxidative stress indicators subsequent to endurance. The research involved forty-one hunting dogs, with equal representations of Alpine Brack Dachshund, Istrian Coarse-Haired Hound, and Posavina Hound. The dogs were categorized into higher frequency activity (n=22) and lower frequency activity (n=19) groups. Endurance was defined as a wild-boar hunt lasting for eight hours at an outside air temperature amounting to 10°C. Endurance had an impact on several parameters: an increased white blood cell count, neutrophils, and mean corpuscular hemoglobin concentration values, but decreased values of eosinophils and lymphocytes. Non-enzymatic biochemical indicators revealed higher energy expenditure (decreased glucose, total protein, and albumin concentration), hemoconcentration (decreased iron concentration), and elevated enzyme activity (AST, ALT, ALP, and CK-MB) but lower catalase activity. In terms of activity frequency, enzyme biomarker activity showed significant differences. ALT activity in both low- and high-frequency activity canines was notably higher (P&lt;0.05) post-endurance compared to pre-endurance levels. ALP activity was significantly higher (P&lt;0.05) post intense physical activity in higher frequency activity canines, yet lower (P&lt;0.05) in lower activity frequency canines compared to their pre-endurance status. In conclusion, both tested canine groups demonstrated notable signs of oxidative stress subsequent to endurance, without differences between activity frequencies.

Protective effects of cupressuflavone against doxorubicin-induced hepatic damage in rats

Doxorubicin (DOX) is a potent chemotherapeutic agent that is used in various sorts of malignancies. However, its uses are restricted owing to its deleterious effects on different organs including the liver. Cupressuflavone (CUP) is a plant-based flavonoid which is well known for its biological as well pharmacological potential. Our investigation aimed to evaluate the ameliorative potential of CUP against DOX provoked liver toxicity in rats. Twenty-four albino rats (Rattus norvegicus) were distributed into four distinct groups such as control, DOX (3 mg/kg), co- administrated DOX (3 mg/kg) + CUP (40 mg/kg) and CUP (40 mg/kg) only. DOX exposure reduced catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), Glutathione reductase (GSR), glutathione-S-transferase (GST) activities and glutathione (GSH) content while escalating the levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Besides, the levels of ALT, AST and ALP were increased in response to DOX exposure. Furthermore, administration of DOX upregulated the levels of Interleukin-6 (IL-6), Nuclear factor kappa-B (NF-κB), Interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and the activity of cyclooxygenase-2 (COX-2). The treatment of DOX reduced the levels of Bcl-2 while escalating the levels of Caspase-3, Caspase-9 and Bax. Similarly, DOX intoxication instigated various histopathological disruptions in hepatic tissues of rats. However, supplementation of CUP notably (p < 0.05) restored abovementioned hepatic dysregulations owing to its anti-oxidative, anti-inflammatory as well as anti-apoptotic potential. Our results manifested that CUP could be used as hepatoprotective agent againt DOX induced liver damage in rats.

Comparative impact of replacing fish meal with azolla on growth, water quality, and physiology of red tilapia fingerlings at varying salinities.

A 210-day experiment to assess the efficacy of substituting azolla plant powder at levels of 0, 20, 40, and 60% for fish meal on red tilapia fingerlings (RTF, initial weight of 18.23 ± 0.12 g) performance under salinity levels of 5, 18, and 28ppt. Among the various conditions, RTF-fed 20% azolla at 28 and 5ppt salinity showcased the highest specific growth rate (SGR), whereas the lowest SGR was observed in fish-fed 60% azolla at 5ppt salinity. Upon azolla incorporation, noteworthy elevations in phytoplankton, zooplankton, dissolved oxygen (DO), pH, NH3, and NO3 were noted and conversely, azolla introduction led to decreased NH4 and NO2 concentrations in all salinity levels. Further, a significant (p < 0.05) interaction between azolla levels and water salinity (S×A) significantly impacted the hematological parameters of RTF. The highest levels of superoxide dismutase (SOD), catalase (CAT), and total protein (TP) were found in RTF-fed 20% azolla at 28ppt salinity, while the lowest CAT and TP levels occurred in RTF-fed 60% azolla at 5ppt salinity. The highest aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were recorded in the RTF group fed 60% azolla at 5ppt salinity, with the lowest values seen in the group given 20% azolla at 28ppt salinity. RTF fed a 20% azolla diet at 18ppt salinity exhibited the highest lysozyme value, in contrast to the lowest value observed in the RTF group fed the control diet at 18ppt salinity. In conclusion, this study recommends the utilization of azolla at inclusion levels ranging from 20 to 40%, as it has the potential to notably enhance the immune system and elevate the survival rate of RTF.

Copper toxicity in juvenile largemouth bass (Micropterus salmoides): acute toxicity bioassay and oxidative stress response in gut and kidney

Aquaculture intensification has resulted in serious disease outbreaks in largemouth bass production. Compounds containing copper (Cu) are widely used as therapeutic agents in aquaculture. Currently, Cu misuse has been a severe issue in largemouth bass farming. However, few investigations have been performed on Cu toxicity in largemouth bass so far. In this study, an acute and a chronic toxicity test was carried out to determine the toxicity and the recommended dose of waterborne Cu in largemouth bass. In the acute toxicity bioassay, fish (2.58 ± 0.03 g) were exposed to 0 (control), 3, 6, 9, 18, or 30 mg/L Cu, and the results showed that the 96-h LC50 of waterborne Cu was 12.78 mg/L. Then a 30-day chronic toxicity test containing six treatments (i.e., 0, 51.3, 164, 513, 1640, and 5130 μg/L Cu) was conducted to investigate the influence of Cu on intestinal and renal health in terms of oxidative stress in juvenile largemouth bass (2.69 ± 0.02 g). The results showed that Cu concentrations at and above 51.3 μg/L significantly increased the malondialdehyde contents (in the intestine) and simultaneously decreased total superoxide dismutase activity levels (in the intestine and kidney), glutathione peroxidase activity levels (in the kidney), and reduced glutathione contents (in the kidney), compared to control. In contrast to control, fish exposed to high Cu concentrations (at and above 1640 μg/L) demonstrated lower catalase activity levels in the intestine and kidney. Based on the findings in the study, waterborne Cu content for largemouth bass farming was recommended to be less than 51.3 μg/L.

Effects of soil pH on the growth, soil nutrient composition, and rhizosphere microbiome of Ageratina adenophora.

Ageratina adenophora is an invasive weed species found in many countries. Methods to control the spread of this weed have been largely unsuccessful. Soil pH is the most important soil factor affecting the availability of nutrients for plant and impacting its growth. Understanding the mechanisms of the influence of soil pH on the growth of A. adenophora may help to develop effective control measures. In this study, we artificially changed the soil pH in pot experiments for A. adenophora. We studied the effects of acidic (pH 5.5), weakly acidic (pH 6.5), neutral (pH 7.2), and alkaline (pH 9.0) soils on the growth, availability of soil nutrients, activity of antioxidant enzymes, levels of redox markers in the leaves, and the structure and diversity of the rhizosphere microbiome. Soil with a pH 7.2 had a higher (47.8%) below-ground height versus soils of pH 5.5 at day 10; plant had a higher (11.3%) above-ground height in pH 7.2 soils than pH 9.0 soils at day 90; no differences in the fresh and dry weights of its above- and belowground parts, plant heights, and root lengths were observed in plants growing in acid, alkaline, or neutral pH soil were observed at day 180. Correspondingly, the antioxidant enzymes SOD (superoxide dismutase), POD (peroxidase), CAT (catalase) and redox markers GSH (glutathione) and MDA (malondialdehyde) were measured in the leaves. Significant differences existed in the activities of CAT and the levels of GSH between those growing in acidic and alkaline soils and those in neutral pH soil at day 90; however, only lower (36.8%) CAT activities in those grown at pH 5.5 than those grown at pH 7.2 were found at day 180. Similarly, significant differences in available P (16.89 vs 3.04 mg Kg-1) and total K (3.67 vs 0.96 mg Kg-1), total P (0.37 vs 0.25 g Kg-1) and total N (0.45 vs 1.09 g Kg-1) concentrations were found between the rhizosphere soils of A. adenophora grown at pH 9.0 and 7.2 at day 90; no such differences were seen at day 180. High throughput analyses of the 16S rRNA and ITS fragments showed that the rhizosphere microbiome diversity and composition under different soil pH conditions changed over 180 days. The rhizosphere microbiomes differed in diversity, phylum, and generic composition and population interactions under acid and alkaline conditions versus those grown in neutral soils. Soil pH had a greater impact on the diversity and composition of the prokaryotic rhizosphere communities than those of the fungal communities. A. adenophora responded successfully to pH stress by changing the diversity and composition of the rhizosphere microbiome to maintain a balanced nutrient supply to support its normal growth. The unusual pH tolerance of A. adenophora may be one crucial reason for its successful invasion. Our results suggest that attempts use soil pH to control its invasion by changing the soil pH (for example, using lime) will fail.

Exogenous application of gibberellic acid reduces antioxidant capacity of leaves, resulting in increased Tipburn damages in Lisianthus cultivars

Tipburn (calcium (Ca) deficiency disorder of new leaf tips) is a severe problem in horticultural crop production. Studies have focused on the fact that tipburn commonly occurs during bolting and shown that plants exhibited greater tipburn damage than the control when bolting was induced using exogenous gibberellic acid (GA). However, why exogenous GA application enhances tipburn damage and why tipburn occurs during bolting remains unclear. To address this knowledge gap, we investigated the occurrence of tipburn, Ca concentrations in each organ, antioxidant capacity (superoxide dismutase (SOD) and catalase activity), and gene expression in three lisianthus cultivars (‘Umihonoka’ (UH), ‘Reina White’ (RW), and ‘Voyage Peach’ (VP)), where bolting was induced through exogenous active GA application (GA treatment) and discussed the cause of tipburn occurring during bolting. The incidence and severity of tipburn in the GA treatment were significantly higher than those in the control group in all cultivars. The Ca concentrations in the top leaves of the GA treatment were similar to or higher than those in the control treatment for all cultivars. In contrast, SOD activity in VP was significantly lower in GA treatment than that in the control, which was consistent with the results of SOD-CuZn expression. Additionally, significantly lower catalase activity at GA treatment were detected in the UH and RW than at the control. Recent studies have reported that reactive oxygen species and antioxidants significantly affect the appearance of blossom-end rot. Therefore, exogenous GA application decreased the antioxidant capacity of the upper leaves, resulting in increased tipburn damage. In addition, it is known that a decrease in antioxidant capacity and an increase in H2O2 concentration in leaves of Arabidopsis is a trigger for the initiation of bolting. Our findings provide important insight into the causes and ecological implications of tipburn during bolting.

A blend of microalgae and cyanobacteria produced from industrial waste outputs for the enrichments of Artemia salina: Effects on growth performance, antioxidant status and anomalies rate of European seabass (Dicentrarchus labrax) larvae

The recent fast development of the microalgae-related biotechnologies has enabled the availability of sustainable and nutrients-rich raw materials to be used as substitution of conventional sources in aquafeed formulation. However the cost of energy of the photobioreactors used to produce these microorganisms still constrained their wider inclusion into aquafeed compounds. By exploiting industrial waste outputs, Nannochloropsis sp. and Spirulina sp. were produced and utilised to formulate two experimental enrichments (LM1 and LM2). During a 60 days trial, their efficacy have been tested as Artemia metanauplii enrichments in the diet of European seabass (Dicentrarchus labrax) larvae, in comparison to a commercial control. Larvae were fed with isonitrogenous and isolipidic dietary treatments. Each dietary treatment presented a specific profile for the long chain polyunsaturated fatty acids ARA, DHA and EPA. Ratio of DHA/EPA in enriched Artemia of 4:1 as in the case of LM1 and LM2 in the presence of 1.4% of ARA (as a % on total fatty acid) guaranteed equal results to the control which displayed a ratio of DHA/EPA of 2:1 with 2.2% of ARA. No significant effects of the dietary treatments were detected in final survival, growth performance and incidence of skeletal anomalies. Regarding oxidative status, larvae fed with LM2 enrichment presented lower catalase activity than control larvae with no signs of oxidative damage, suggesting a potential antioxidant effect of LM2. The present study contributes to expanding the existing literature on successful utilisation of microalgae and cyanobacteria, used to produce valuable nutrients, in a perspective of circular nutrients economy.

Redox modulation of oxidatively-induced DNA damage by ascorbate enhances both in vitro and ex-vivo DNA damage formation and cell death in melanoma cells

Elevated genomic instability in cancer cells suggests a possible model-scenario for their selective killing via the therapeutic delivery of well-defined levels of further DNA damage. To examine this scenario, this study investigated the potential for redox modulation of oxidatively-induced DNA damage by ascorbate in malignant melanoma (MM) cancer cells, to selectively enhance both DNA damage and MM cell killing. DNA damage was assessed by Comet and ɣH2AX assays, intracellular oxidising species by dichlorofluorescein fluorescence, a key antioxidant enzymatic defence by assessment of catalase activity and cell survival was determined by clonogenic assay. Comet revealed that MM cells had higher endogenous DNA damage levels than normal keratinocytes (HaCaT cells); this correlated MM cells having higher intracellular oxidising species and lower catalase activity, and ranked with MM cell melanin pigmentation. Comet also showed MM cells more sensitive towards the DNA damaging effects of exogenous H2O2, and that ascorbate further enhanced this H2O2-induced damage in MM cells; again, with MM cell sensitivity to induced damage ranking with degree of cell pigmentation. Furthermore, cell survival data indicated that ascorbate enhanced H2O2-induced clonogenic cell death selectively in MM cells whilst protecting HaCaT cells. Finally, we show that ascorbate serves to enhance the oxidising effects of the MM therapeutic drug Elesclomol in both established MM cells in vitro and primary cell cultures ex vivo. Together, these results suggest that ascorbate selectively enhances DNA damage and cell-killing in MM cells. This raises the option of incorporating ascorbate into clinical oxidative therapies to treat MM.