PurposeAcanthamoeba species are eucaryotic protozoa found predominantly in soil and water. They cause ulceration and vision loss in the cornea (Acanthamoeba keratitis) and central nervous system (CNS) infection involving the lungs (granulomatous amoebic encephalitis). Antiparasitic drugs currently used in the treatment of infections caused by Acanthamoeba species are not effective at the desired level in some anatomical regions such as the eye and CNS. The existence of an agent effective against both cysts and trophozoites has not yet been proven. Drugs used for treatment of Acanthamoeba infrections are still limited.MethodThe present study investigates amoebicidal activites of various concentrations of ethanolic fruit extract of E. umbellata (EU) (40, 20, 10, 5, 2.5, 1.25, 0.625 mM/mL), silver nanoparticles (AgNP) that are synthesized from EU and confirmed with characterization tests (20, 10, 5, 1, 0.5 mM/mL), and lauric acid (LA) in EU detected with gas chromatography-mass spectrometry (GC-MS) against A. castellanii trophozoites. In addition, DNA-preserving activities of EU, AgNP and LA were studied on pBR322 plasmid DNA, following damage induced with hydroxyl radical (-OH). Cytotoxicity of EU over HeLa cells was examined with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Furthermore, the effects over the expression of SOD and CAT genes, which are coding oxidative stress enzymes in trophozoites, and expression of genes responsible for pseudocyst and cyst formation (CSII and CSP21, respectively) were investigated following methanol-induced stress, with reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR).ResultsAt highest concentrations, EU, AgNP and LA showed lethal effects against majority of trophozites at 24 th h and against all trophozoites at 48th hour. EU at 5 mg/mL concentration and LA at 1, 0.8, 0.6, 0.4 mM/mL concentrations prevented DNA damage. A dose-dependent decrease in cell viability was observed, EU was found to be non-cytotoxic for 53.82% of HeLa cells at 72 nd h even at 40 mg/mL concentration. Greatest inhibitory effects were found with EU, AgNP and LA on CSII, EU on CAT, LA on CSP21, and hydrogen peroxide (H2O2) on SOD genes.ConclusionThe findings of this study show that EU, LA and AgNPs can be used in a controlled manner to combat A. castellanii infections by reducing or blocking the activity of the parasite's antioxidant enzymes (SOD and CAT), without giving the parasite a chance to initiate the process of pseudocyst or proper cyst formation.

Per- and polyfluoroalkyl substances (PFAS) are a class of persistent organic pollutants that pose a growing threat to environmental and human health. Soil acts as a long-term reservoir for PFAS, potentially impacting soil biodiversity and ecosystem function. Earthworms, as keystone species in soil ecosystems, are particularly vulnerable to PFAS exposure. In this study, we investigated the sublethal effects of three short-chain (C4-C6) next-generation perfluoropropylene oxide acids (PFPOAs) on the earthworm Eisenia fetida, using a legacy perfluoroalkyl carboxylic acid (PFCA), perfluorooctanoic acid (PFOA), as a reference. We assessed a suite of biochemical endpoints, including markers for oxidative stress (catalase and superoxide dismutase activity), immunity (phenol oxidase activity), neurotoxicity (acetylcholinesterase activity), and behavioural endpoints (escape test). Results indicate that all tested PFAS, even at sub-micromolar concentrations, elicited significant effects across multiple physiological domains. Interestingly, HFPO-DA demonstrated the most substantial impact across all endpoints tested, indicating broad and significant biochemical and neurotoxic effects. Our findings underscore the potential risks of both legacy and emerging PFAS to soil ecosystems, emphasising the need for further research to understand the long-term consequences of PFAS contamination.

Inorganic arsenic (iAs) is a persistent bioaccumulation carcinogen that is most abundant in soils in the form of arsenite-As (III) and arsenate-As (V). However, there is currently very little explicit evidence about cytotoxicity of As on soil organisms. Moreover, toxicological data for iAs and proteotoxicity is shortage. The purpose of the present work is to elucidate the cytotoxicity mechanism of As (III) and As (V) to earthworms, a soil ecological sentinel species, and the molecular mechanisms by which As (III)/As (V) directly bind to antioxidative enzyme Cu/Zn-superoxide dismutase (Cu/Zn-SOD). Results indicate that iAs triggered cell membrane injury and genotoxicity. As (V) (56.15 %) induced lower cell viability than As (III) (61.88 %). Higher ROS and lipid peroxidation level in As (V) support greater cytotoxicity. Differences in cellular uptake due to valence induced diverse levels of oxidative stress and cytotoxicity. At the molecular level, As (III) (129.33 %) induced higher Cu/Zn-SOD activity than As (V) (110.75 %). Changes in backbone, secondary structure, amino acid microenvironment and particle size of Cu/Zn-SOD further revealed the mechanisms of differential molecular toxicity of As (III) and As (V). Binding reactions with Cu/Zn-SOD explain differences in molecular toxicity. Collective research showed that iAs induced oxidative stress and binding reactions determine the difference of SOD activity between As (III) and As (V) at the cellular level. This work offers new insights into the health risk assessment of As.

Antioxidant complex enzymes have a significant role in cellular homeostasis control in plants, and they inhibit the toxic action of reactive oxygen species when they are in excess. There are many antioxidant enzymes executing this role; among these, superoxide dismutase, catalase, and ascorbate peroxidase are reported as the most studied in this process, as they prevent free radicals from becoming more reactive and toxic to cells. Thus, this research was conducted to evaluate antioxidant enzyme expression in response to hydric stress at the reproductive stage in upland rice genotypes. Three genotypes from the upland rice breeding program on agreement between UFLA, EPAMIG, and EMBRAPA, CMG2093, CMG2172, and BRSMG Relampago, were used as controls. Genotypes were grown under field conditions with supplementary irrigation during the whole crop cycle, and hydric stress was induced in the reproductive phase before panicle emission. Seedlings were used in enzyme analyses from the emergence test and IVE on substrate (soil+sand at a 2:1 rate) at 70% and 10% field capacity. Significant differences were observed among genotypes for vigor tests. In biochemical tests, the CMG2093 genotype had lower damage on hydric deficit, with the best performance under hydric restriction conditions, being considered tolerant for this stress type.

Polystyrene nanoplastics (PS-NPs) have been demonstrated to accumulate in organisms especially from soil and exhibit neurotoxicity. However, the specific mechanisms by which PS-NPs caused neurotoxic effects remain largely unexplored. In this study, we employed PS-NPs with a diameter of 50 nm as the toxicant and used estimated exposure concentrations which are similar to those found in Chinese agricultural soil (i.e., 0, 1, 5 and 10 mu g/mL). We found that PS-NPs induced significant neurotoxicity and behavioral damage in nematodes. Taking advantage of neuronal-specific reporter nematodes, we unveiled the order of neuronal damage induced by PSNPs being DAergic neurons, followed by Achergic neurons and GABAergic neurons. Additionally, PS-NPs significantly reduced the neurotransmitter levels corresponding to these three types of neurons, with the order of reduction being Ach followed by DA and GABA. Moreover, we demonstrated that PS-NPs led to an increase in ROS production, the activation of gst-4 and a decrease in Sod-2 protein content. Furthermore, we unveiled that Sod-2 could suppress the generation of ROS induced by PS-NPs. Then we proved that the pretreatment with mitochondrial ROS scavenger Mitoquinone (Mito Q) was able to alleviate PS-NPs-induced neurotoxic effects and behavioral damage by scavenging ROS and subsequently regulating Sod-2 protein expression. In summary, we have demonstrated for the first time that ROS-mediated reduction of Sod-2 protein plays a crucial role in PS-NPsinduced neurotoxicity and behavioral damage. Furthermore, Mito Q shows potential therapeutic value in alleviating the toxic effects of PS-NPs, providing new insights for the prevention and treatment of PS-NPs-induced neurotoxicity.

Zinc (Zn) deficiency and salt stress are well-known soil problems and often happen parallelly in cultivated soils. In this study, Zn-amino acid complexes (Zn-AAc) were used as a source of Zn to determine their effects on salt-induced damage in wheat plants. The bread wheat (Triticum aestivum L. cvs. Kavir) was supplied with Zn-glycine (Zn-Gly), Zn-alanine (Zn-Ala), and ZnSO4 as Zn sources at three salinity levels (EC 2, 4 and 6 dS m(-)). Salinity caused a significant decrease in shoot dry matter and grain yield of wheat, but this negative effect was significantly improved by the application of Zn-AAc. Salt stress decreased shoot and grain Zn concentration, but this reduction was lower in plants supplied by Zn-AAc. Calcium (Ca) and potassium (K) concentrations were increased in a shoot by salinity stress while decreased in grain. Sodium (Na) concentration decreased in shoot and grain by using Zn-AAc. At all of the salinity levels, wheat supplied with Zn-AAc had lower lipid peroxidation compared to those grown under the ZnSO4 source. Application of Zn-AAc increased the activities of catalase (CAT) and superoxide dismutase (SOD) in the roots of wheat plants in saline conditions. Based on the results, the adverse effects of salinity stress on wheat plants can moderately improve with Zn-AAc application.

Antioxidant responses play a crucial role in combating free radical damage induced by drought stress. In guar plants, the antioxidant mechanism is crucial for stress tolerance; however, the specific antioxidant response in individual guar genotypes remains unclear. This study investigates the physiological, biochemical, and transcriptional responses of four guar genotypes to drought stress by maintaining soil moisture content (SMC) at varying levels: control (100% FC), medium (60% FC), and severe (20% FC). Among the genotypes examined, HG-563 and HG-365 exhibit higher leaf relative water content (RWC) and total chlorophyll/carotenoid content, indicating lesser inhibition under drought stress compared to HG-75 and RGC-936. Notably, HG-563 and HG-365 demonstrate a significant increase in activities of key antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), ascorbate (AsA), and glutathione (GSH) during medium and severe drought stress conditions. This observation is further supported by in-gel activity assays revealing a notable upregulation of Cu/ZnSOD and POD isozymes, which is consistent with higher expression levels of Cu/ZnSOD and POD genes at the transcriptional level. Consequently, these results highlight the comparatively higher drought tolerance of HG-563 and HG-365 genotypes. The findings shed light on the activation of antioxidant responses in drought-tolerant guar genotypes under stress conditions, emphasizing the crucial role of antioxidant enzymes in the drought tolerance mechanism of guar plants.

Triclosan (TCS) is widely used in a number of industrial and personal care products. This molecule can induce reactive oxygen species (ROS) production in various cell types, which results in diverse types of cell responses. Therefore, the aim of the present study was to summarize the current state of knowledge of TCS-dependent ROS production and the influence of TCS on antioxidant enzymes and pathways. To date, the TCS mechanism of action has been widely investigated in non -mammalian organisms that may be exposed to contaminated water and soil, but there are also in vivo and in vitro studies on plants, algae, mammalians, and humans. This literature review has revealed that mammalian organisms are more resistant to TCS than non -mammalian organisms and, to obtain a toxic effect, the effective TCS dose must be significantly higher. The TCS-dependent increase in the ROS level causes damage to DNA, protein, and lipids, which together with general oxidative stress leads to cell apoptosis or necrosis and, in the case of cancer cells, faster oncogenesis and even initiation of oncogenic transformation in normal human cells. The review presents the direct and indirect TCS action through different receptor pathways.

Tenebrio molitor L., also known as the mealworm, is a polyphagous insect pest that infests various stored grains worldwide. Both the adult and larval stages can cause significant damage to stored grains. The present study focused on isolating entomopathogenic fungi from an infected larval cadaver under environmental conditions. Fungal pathogenicity was tested on T. molitor larvae and pupae for 12 days. Entomopathogenic fungi were identified using biotechnological methods based on their morphology and the sequence of their nuclear ribosomal internal transcribed spacer (ITS). The results of the insecticidal activity indicate that the virulence of fungi varies between the larval and pupal stages. In comparison to the larval stage, the pupal stage is highly susceptible to Metarhizium rileyi, exhibiting 100% mortality rates after 12 days (lethal concentration 50 [LC50] = 7.8 x 10(6) and lethal concentration 90 (LC90) = 2.1 x 10(13) conidia/mL), whereas larvae showed 92% mortality rates at 12 days posttreatment (LC50 = 1.0 x 10(6) and LC90 = 3.0 x 10(9) conidia/mL). The enzymatic analyses revealed a significant increase in the levels of the insect enzymes superoxide dismutase (4.76-10.5 mg(-1)) and glutathione S-transferase (0.46-6.53 mg(-1)) 3 days after exposure to M. rileyi conidia (1.5 x 10(5) conidia/mL) compared to the control group. The findings clearly show that M. rileyi is an environmentally friendly and effective microbial agent for controlling the larvae and pupae of T. molitor.

Zhe-Maidong, a cultivar of Ophiopogon japonicus is a prominent traditional herbal medicine rich in saponins. This study explored the mechanism of saponin biosynthesis and its role in alleviating Cd-induced oxidative damage in the Zhe-Maidong cultivar using three experimental groups undergoing Cd stress. In the Cd-contaminated soil treatment, total saponins were 1.68 times higher than those in the control. The saponin content in the Cd-2 and Cd-3 treatments was approximately twice as high as that in the Cd-CK treatment. These findings revealed that Cd stress leads to total saponin accumulation. Metabolomic analysis identified the accumulated saponins, primarily several monoterpenoids, diterpenoids, and triterpenoids. The increased saponins exhibited an antioxidant ability to prevent the accumulation of Cd-induced reactive oxygen species (ROS). Subsequent saponin application experiments provided strong evidence that saponin played a crucial role in promoting superoxide dismutase (SOD) activity and reducing ROS accumulation. Transcriptome analysis revealed vital genes for saponin synthesis under Cd stress, including SE , two SSs , and six CYP450s, positively correlated with differentially expressed metabolite (DEM) levels in the saponin metabolic pathway. Additionally, the TF-gene regulatory network demonstrated that bHLH1 , bHLH3 , mTERF , and AUX/IAA transcript factors are crucial regulators of hub genes involved in saponin synthesis. These findings significantly contribute to our understanding of the regulatory network of saponin synthesis and its role in reducing oxidative damage in O . japonicum when exposed to Cd stress.