Antimicrobial sensitisers: Gatekeepers to avoid the development of multidrug-resistant bacteria.

The resistance of multidrug-resistant bacteria to existing antibiotics forces the continued development of new antibiotics and antibacterial agents, but the high costs and long timeframe involved in the development of new agents renders the hope that existing antibiotics may again play a part. The "antibiotic adjuvant" is an indirect antibacterial strategy, but its vague concept has, in the past, limited the development speed of related drugs. In this review article, we put forward an accurate concept of a "non-self-antimicrobial sensitisers (NSAS)", to distinguish it from an "antibiotic adjuvant", and then discuss several scientific methods to restore bacterial sensitivity to antibiotics, and the sources and action mechanism of existing NSAS, in order to guide the development and further research of NSAS.

Dopaminergic and serotoninergic systems as preferential targets of the pyrethroid tefluthrin exposure in the rat brain.

The monoaminergic systems dopamine (DA) and serotonin (5-HT) play important roles in neuromodulation, such as motor control, cognitive, affective, and neuroendocrine functions. In the present research study, we addressed the hypothesis that exposure to Type I pyrethroid tefluthrin may specifically target the dopaminergic and serotoninergic systems. Tefluthrin could modify brain monoamine neurotransmitters, DA and 5-HT levels as well as dopaminergic and serotoninergic signaling pathways. Adult male Wistar rats were treated with tefluthrin [2.2, 4.4 and 5.5 mg/kg bw, equivalent to 1/10, 1/5 and 1/4 of the acute oral rat lethal dose 50 (LD50) value] by oral gavage, six days. After last dose of tefluthrin, DA and 5-HT and metabolites levels were determined in brain regions (striatum, hippocampus, prefrontal cortex and hypothalamus). Tefluthrin induced a decrease of DA, 5-HT and metabolites contents, in a brain regional- and dose-related manner. The major decreases in DA and 5-HT contents were observed in prefrontal cortex tissue. Here, we studied that in vivo exposure to tefluthrin may alter DA and 5-HT neurotransmission in prefrontal cortex. Transcripts related to (i) dopaminergic [dopamine transporter 1 (Dat1), tyrosine hydroxylase (TH), dopamine receptors (Drd1, Drd2)], (ii) serotoninergic [serotonin transporter (SERT), tryptophan hydroxylase 2 (TPH2), serotonin receptors (5-HT1A, 5-HT2A)] and (iii) DA and 5-HT degradation [monoamine oxidases (MAOA, MAOB)] signaling pathways were investigated. Results showed that tefluthrin induced down-regulation of transcripts responsible for the synthesis and action of DA (TH, Drd1, Drd2) and 5-HT (SERT, TPH2). In contrast, tefluthrin treatment induced up-regulation of genes involved in DA transporter (Dat1), 5-HT receptors (5-HT1A, 5-HT2A) and monoamine oxidases (MAOA, MAOB). Given the integral roles of mitochondrial dysfunction and dopaminergic and serotoninergic alterations as hallmarks of neurodegenerative diseases, our data suggest that tefluthrin may be a candidate for pesticides contributing to neurodegenerative disorders pathogenesis by causing damage to the DA and 5-HT systems.

Oxidative stress, the blood-brain barrier and neurodegenerative diseases: The critical beneficial role of dietary antioxidants.

In recent years, growing awareness of the role of oxidative stress in brain health has prompted antioxidants, especially dietary antioxidants, to receive growing attention as possible treatments strategies for patients with neurodegenerative diseases (NDs). The most widely studied dietary antioxidants include active substances such as vitamins, carotenoids, flavonoids and polyphenols. Dietary antioxidants are found in usually consumed foods such as fresh fruits, vegetables, nuts and oils and are gaining popularity due to recently growing awareness of their potential for preventive and protective agents against NDs, as well as their abundant natural sources, generally non-toxic nature, and ease of long-term consumption. This review article examines the role of oxidative stress in the development of NDs, explores the 'two-sidedness' of the blood-brain barrier (BBB) as a protective barrier to the nervous system and an impeding barrier to the use of antioxidants as drug medicinal products and/or dietary antioxidants supplements for prevention and therapy and reviews the BBB permeability of common dietary antioxidant suplements and their potential efficacy in the prevention and treatment of NDs. Finally, current challenges and future directions for the prevention and treatment of NDs using dietary antioxidants are discussed, and useful information on the prevention and treatment of NDs is provided.

Oxidative stress and mitochondrial damage in lambda-cyhalothrin toxicity: A comprehensive review of antioxidant mechanisms.

Lambda-cyhalothrin, also known as cyhalothrin, is an efficient, broad-spectrum, quick-acting pyrethroid insecticide and acaricide and the most powerful pyrethroid insecticide in the world. However, there is increasing evidence that lambda-cyhalothrin is closely related to a variety of toxicity drawbacks (hepatotoxicity, nephrotoxicity, neurotoxicity and reproductive toxicity, among others) in non-target organisms, and oxidative stress seems to be the main mechanism of toxicity. This manuscript reviews the oxidative and mitochondrial damage induced by lambda-cyhalothrin and the signalling pathways involved in this process, indicating that oxidative stress occupies an important position in lambda-cyhalothrin toxicity. The mechanism of antioxidants to alleviate the toxicity of lambda-cyhalothrin is also discussed. In addition, the metabolites of lambda-cyhalothrin and the major metabolic enzymes involved in metabolic reactions are summarized. This review article reveals a key mechanism of lambda-cyhalothrin toxicity-oxidative damage and suggests that the use of antioxidants seems to be an effective method for preventing toxicity.

Conjugated linoleic acid (CLA) as a functional food: Is it beneficial or not?

Conjugated linoleic acid (CLA) has attracted great attention in recent years as a popular class of functional food that is broadly used. It refers to a group of geometric and positional isomers of linoleic acid (LA) with a conjugated double bond. The main natural sources of CLA are dairy products, beef and lamb, whereas only trace amounts occur naturally in plant lipids. CLA has been shown to improve various health issues, having effects on obesity, inflammatory, anti-carcinogenicity, atherogenicity, immunomodulation, and osteosynthesis. Also, compared to studies on humans, many animal researches reveal more positive benefits on health. CLA represents a nutritional avenue to improve lifestyle diseases and metabolic syndrome. Most of these effects are attributed to the two major CLA isomers [conjugated linoleic acid cis-9,trans-11 isomer (c9,t11), and conjugated linoleic acid trans-10,cis-12 isomer (t10,c12)], and their mixture (CLA mix). In contrast, adverse effects of CLA have been also reported, such as glucose homeostasis, insulin resistance, hepatic steatosis and induction of colon carcinogenesis in humans, as well as milk fat inhibition in ruminants, lowering chicken productivity, influencing egg quality and altering growth performance in fish. This review article aims to discuss the health benefits of CLA as a nutraceutical supplement and highlight the possible mechanisms of action that may contribute to its outcome. It also outlines the feasible adverse effects of CLA besides summarizing the recent peer-reviewed publications on CLA to ensure its efficacy and safety for proper application in humans.

Cancer Metabolism: The Role of ROS in DNA Damage and Induction of Apoptosis in Cancer Cells.

Cancer is a huge challenge for people worldwide. High reactive oxygen species (ROS) levels are a recognized hallmark of cancer and an important aspect of cancer treatment research. Abnormally elevated ROS levels are often attributable to alterations in cellular metabolic activities and increased oxidative stress, which affects both the development and maintenance of cancer. Moderately high levels of ROS are beneficial to maintain tumor cell genesis and development, while toxic levels of ROS have been shown to be an important force in destroying cancer cells. ROS has become an important anticancer target based on the proapoptotic effect of toxic levels of ROS. Therefore, this review summarizes the role of increased ROS in DNA damage and the apoptosis of cancer cells caused by changes in cancer cell metabolism, as well as various anticancer therapies targeting ROS generation, in order to provide references for cancer therapies based on ROS generation.

Bifurcaria bifurcata extract exerts antioxidant effects on human Caco-2 cells.

The present research study investigated the potential protective effect of Bifurcaria bifurcata extract on cell viability and antioxidant defences of cultured human Caco-2 cells submitted to oxidative stress induced by tert-butylhydroperoxide (tert-BOOH). Aqueous extracts were firstly characterized in terms of total phenolic contents. Concentrations of reduced glutathione (GSH) and malondialdehyde (MDA), generation of reactive oxygen species (ROS), nitric oxide (NO) production, antioxidant enzymes activities [NADPH quinone dehydrogenase 1 (NQO1) and glutathione S-transferase (GST)], caspase 3/7 activity and gene expression linked to apoptosis, proinflammation and oxidative stress signaling pathways were used as markers of cellular oxidative status. B. bifurcata extract prevented the cytotoxicity, the decrease of GSH, the increase of MDA levels and the ROS generation induced by tert-BOOH. B. bifurcata extract prevented the significant decrease of NQO1 and GST activities, and the significant increase of caspase 3/7 activity induced by tert-BOOH. B. bifurcata extract also caused an over-expression of GSTM2, Nrf2 and AKT1 transcriptors, as well as reduced ERK1, JNK1, Bax, BNIP3, NFκB1, IL-6 and HO-1 gene expressions induced by tert-BOOH suggesting an increase in cellular resistance against oxidative stress. The results of the biomarkers analyzed show that treatment of Caco-2 cells with B. bifurcata extract enhance antioxidant defences, which imply an improved cell response to an oxidative challenge. B. bifurcata extract possesses strong antioxidant properties and may be a potential effective alternative to oxidant agents in the functional food industry.

The potential of CD38 protein as a target for autoimmune diseases.

Cluster of differentiation 38 (CD38) is a multifunctional cell surface protein involved in nicotinamide adenine dinucleotide (NAD+) homeostasis in types of cells and tissues, which can be found in many immune cells and non-immune cells. Previous studies have shown that CD38 plays an important role in regulating innate immunity. Recently, many studies have revealed the importance of CD38 in autoimmune diseases, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), multiple sclerosis (MS), type 1 diabetes (T1D) and inflammatory bowel disease, among others. In this report, we will briefly discuss the complex immunological functions of CD38 and focus on recent advances in the role of CD38 in the development and pathogenesis of autoimmune diseases, as well as their potential as therapeutic targets for systemic diseases, intending to make a comprehensive understanding of CD38 and its promising therapeutic potential in these systemic diseases.

MS4A3-HSP27 target pathway reveals potential for haematopoietic disorder treatment in alimentary toxic aleukia.

Alimentary toxic aleukia (ATA) is correlated with consuming grains contaminated by Fusarium species, particularly T-2 toxin, which causes serious hurt to human and animal health, chiefly in disorders of the haematopoietic system. However, the mechanism of haematopoietic dysfunction induced by T-2 toxin and the possible target pathway for the treatment of T-2 toxin-induced haematopoietic disorder of ATA remains unclear. In this study, genomes and proteomics were used for the first time to investigate the key differential genes and proteins that inhibit erythroid differentiation of K562 cells caused by T-2 toxin, and it was found that heat shock protein 27 (HSP27) and membrane-spanning 4-domains, subfamily A, member 3 (MS4A3) may play an important role in erythroid differentiation. Meanwhile, MS4A3 interference can inhibit the occurrence of erythroid differentiation of K562 cells and promote the phosphorylation of HSP27. Moreover, the binding of HSP27 to MS4A3 in natural state can activate the phosphorylation site of HSP27 (Ser-83), while T-2 toxin can abolish the activation of phosphorylation site by inhibiting the expression of MS4A3. These findings for the first time demonstrated that the MS4A3-HSP27 pathway may function an efficient therapeutic target pathway for treating T-2 toxin elicited haematopoietic disorders of ATA.

The "steric-like" inhibitory effect and mechanism of doxycycline on florfenicol metabolism: Interaction risk.

Most of the studies on doxycycline (DOX) and florfenicol (FF) remain focused on the improvement of antimicrobial activity and antimicrobial spectrum, and there is no relevant report on whether there is interaction between the two drugs after the combination. This research study evaluated the effect of DOX on FF metabolism in vitro and its mechanisms. The findings of this study showed that DOX inhibits FF metabolism in two ways. Firstly, DOX significantly inhibits the expression of CYP3A29, leading to the slower metabolism of FF; secondly, DOX affects the binding of FF to R106 and R372 by competing for the R372 and/or by a "steric-like effect", thus slowing down FF metabolism, which may increase the residual concentration of FF in edible tissues of food producing animals.

Neurotoxicity induced by the pyrethroid lambda-cyhalothrin: Alterations in monoaminergic systems and dopaminergic and serotoninergic pathways in the rat brain.

The effects of Type II pyrethroid lambda-cyhalothrin on dopamine (DA) and serotonin (5-HT) synthesis in rat brain regions (striatum, hippocampus, prefrontal cortex, hypothalamus and midbrain) were studied. Lambda-cyhalothrin (1, 4 and 8 mg/kg bw, oral gavage, 6 days) induced a decrease of DA, 5-HT and metabolites contents, in a brain regional- and dose-related manner. The major decreases in DA and 5-HT contents were observed in hippocampus and prefrontal cortex tissues. This research study also showed in hippocampus and prefrontal cortex, that lambda-cyhalothrin modified the mRNA levels of DA transporter gene (Dat1 up-regulation), 5-HT transporter gene (SERT down-regulation), DA receptor genes (Drd1and Drd2 down-regulation), 5-HT receptor genes (5-HT1A and 5-HT2A down-regulation/up-regulation), DA synthesis gene (TH down-regulation), 5-HT synthesis gene (TPH2 down-regulation), DA and 5-HT degradation genes (MAOA and MAOB up-regulation). These results reveal that lambda-cyhalothrin altered central nervous system (CNS) monoaminergic neurotransmitters. Lambda-cyhalothrin evoked a selective neurotoxic injury to dopaminergic and serotoninergic pathways. These findings may clarify on the pyrethroids-induced neurotoxicity mechanisms and could involve pyrethroids as environmental risk factors leading to the development of neurodegenerative diseases.

Nicotinamide N-methyltransferase protects against deoxynivalenol-induced growth inhibition by suppressing pro-inflammatory cytokine expression.

Deoxynivalenol (DON) is an inevitable contaminant in cereals for infants. Indeed, children's growth retardation caused by widespread DON pollution has become a global problem that cannot be ignored. Accumulating evidence has shown that DON stunts growth in children through pro-inflammatory cytokines. An exogenous increase of methylnicotinamide, a metabolite produced by nicotinamide N-methyltransferase (NNMT), has anti-inflammatory effects, but it is not clear whether NNMT has the same effect, and the role of NNMT in DON-induced inflammation and growth impairment remains indistinct. The present research reports that NNMT is an inflammatory self-protective factor in DON-exposed L02 cells. DON promoted the production of pro-inflammatory cytokines. Furthermore, DON increased NNMT to reduce pro-inflammatory cytokines, including interleukin (IL)-1ß, IL-11 and IL-6, and thus increased IGF-1 and cell viability, alleviating the cell growth inhibition induced by DON. Interestingly, NNMT negatively regulated the expression of IL-1ß through Sirtuin type 1 (SIRT1). Collectively, these findings provide new mechanistic insights into the toxicity of DON-induced growth retardation and inflammatory responses in children.

Neonicotinoids: mechanisms of systemic toxicity based on oxidative stress-mitochondrial damage.

Neonicotinoids are the most widely used pesticides in the world. However, research studies have shown that it can affect the cognitive abilities and health of non-target bees and other wild pollinators by inducing DNA damage, apoptosis and mitochondrial damage, injure to its central nervous system, and it is even developmentally neurotoxic to mammals and humans, with mitochondria being an important target of neonicotinoids. Therefore, this article reviews the role of mitochondrial morphology, calcium ions (Ca2+) homeostasis, respiratory function, apoptosis, and DNA damage in neonicotinoids-induced systemic toxicity. Additionally, it evaluates the protective effects of various active substances including vitamin C, N-acetylcysteine (NAC), curcumin (CUR), glutathione reduced (GSH), caffeic acid phenethyl ester (CAPE), resveratrol, and thymoquinone (TQ) on neonicotinoids-induced toxicity. This review manuscript found that mitochondria are important targets to neonicotinoids. Neonicotinoids can cause DNA damage, apoptosis, protein oxidation, and lipid peroxidation in non-target organisms by altering mitochondrial Ca2+ homeostasis, inhibiting mitochondrial respiration, and inducing reactive oxygen species (ROS) production. Several active substances (vitamin C, NAC, CUR, GSH, resveratrol, CAPE, and TQ) play a protective role against neonicotinoid-induced systemic toxicity by inhibiting ROS signaling pathways, apoptosis, and lipid peroxidation. This review manuscript emphasizes the importance and urgency of the development of neonicotinoid antidotes, emphasizes the prospect of the application of targeted mitochondrial antidotes, and prospects the development of neonicotinoid antidotes in order to provide some strategies for the prevention of neonicotinoid toxicity.

Mitochondria as an important target of metformin: The mechanism of action, toxic and side effects, and new therapeutic applications.

Metformin is the oldest and most commonly used first-line antidiabetic drug because of its good clinical efficacy, high safety, low cost and easy access. At the same time, in recent years, we have found that its role as a therapeutic drug is gradually expanding. A large number of basic studies have shown that metformin may become a promising attractive candidate for drug repurposing. Therefore, it is extremely beneficial to conduct an in-depth discussion on the main mechanism of metformin. As early as the year 1950, studies showed that metformin played a biological role by regulating mitochondria. Then, ground-breaking studies showed that metformin functions by inhibiting complex I in the mitochondrial respiratory chain. Although there are still many controversies about the key molecular targets of metformin, with the emergence of more and more evidence, it gradually came to be concluded that mitochondria play a central role in the application of metformin. Mitochondria are important fulcrums for cell functions. The exact mechanism of action in mitochondria of this pleiotropic anti-hyperglycaemic molecule is still unclear. This review article explores the core role of mitochondria in the pharmacological and toxicological effects of metformin, and summarises the mechanism of action if metformin in mitochondria. It also provides ideas and supporting evidence for the re-development and reuse of metformin as an old drug, as well as new insight into the treatment of human diseases.

Oxidative Stress and Metabolism: A Mechanistic Insight for Glyphosate Toxicology.

Glyphosate (GLYP) is a widely used pesticide; it is considered to be a safe herbicide for animals and humans because it targets 5-enolpyruvylshikimate-3-phosphate synthase. However, there has been increasing evidence that GLYP causes varying degrees of toxicity. Moreover, oxidative stress and metabolism are highly correlated with toxicity. This review provides a comprehensive introduction to the toxicity of GLYP and, for the first time, systematically summarizes the toxicity mechanism of GLYP from the perspective of oxidative stress, including GLYP-mediated oxidative damage, changes in antioxidant status, altered signaling pathways, and the regulation of oxidative stress by exogenous substances. In addition, the metabolism of GLYP is discussed, including metabolites,metabolic pathways, metabolic enzymes, and the toxicity of metabolites. This review provides new ideas for the toxicity mechanism of GLYP and proposes effective strategies for reducing its toxicity.

A "Janus" face of the RASSF4 signal in cell fate.

RASSF4 (Ras-association domain family 4) is a protein-coding gene, regarded as a tumor suppressor regulated by DNA methylation. However, RASSF4 acts as a "Janus" in cell fate: death and survival. This review article focuses on the regulatory mechanisms of RASSF4 on cell death and cell survival and puts forward a comprehensive analysis of the relevant signaling pathways. The participation of RASSF4 in the regulation of intracellular store-operated Ca2+ entry also affects cell survival. Moreover, the mechanism of inducing abnormal expression of RASSF4 was summarized. We highlight recent advances in our knowledge of RASSF4 function in the development of cancer and other clinical diseases, which may provide insight into the controversial functions of RASSF4 and its potential application in disease therapy.

Tefluthrin: metabolism, food residues, toxicity, and mechanisms of action.

Tefluthrin is a Type I pyrethroid insecticide widely used all over the world. Residues of tefluthrin in various agricultural and animal-derived products may be related to potential human health risks. Tefluthrin metabolism in mammals involves hydrolysis of the ester bond to form cyclopropane acid and 4-methylbenzyl alcohol moieties, followed by oxidation. In this review manuscript, we provide crucial information regarding the toxicity of pyrethroids and propose natural antioxidants for amelioration poisoning in humans and animals. We call for the rational use of tefluthrin as an agrochemical product and for greater attention to the residual toxicity caused by tefluthrin in primary and succeeding crops. This greater attention is required given the global use of tefluthrin.

Interaction Between Florfenicol and Doxycycline Involving Cytochrome P450 3A in Goats (Capra hricus).

When two drugs are combined, drug-drug interactions (DDI) often occur. Metabolic DDI usually occur due to inhibition of the metabolism of one drug by the other. This leads to an increase in the plasma concentration of the drug whose metabolism is inhibited. The objective of this research study was to verify the DDI risk of two antibacterial, florfenicol (FF) and doxycycline (DOX) due to metabolism. Because food containing residues of any pharmacologically active substance could potentially constitute a public health hazard, we selected a food producing animal, goat, goat liver microsomes and recombinant metabolic enzymes, for in vivo and in vitro metabolism studies. In vitro experiments showed that CYP3A was the key enzyme subfamily in FF metabolism, DOX slowed down FF metabolism and R440 was possibly the key amino acid in the metabolic interaction between FF and DOX. In vivo studies in the goats showed that DOX inhibited up-regulation of CYP3A24 gene expression produced by FF; in liver and kidney, DOX slightly slowed down FF metabolism. Quantitative prediction of DDI risk suggest that when DOX is used in combination with FF in veterinary medicine, may result in a clinical significant increase of FF plasma and tissue concentrations, resulting a prevalence of harmful tissue residues of medicinal products in the food chain. Through our experimentation, when DOX is used in combination with FF, the withdrawal period of FF in the kidney was extended by 1 day. Otherwise, an appropriate withdrawal period (20 days) of FF was established for FF and DOX combined use to ensure that the animal can be safely slaughtered for food.

The NO-dependent caspase signaling pathway is a target of deoxynivalenol in growth inhibition in vitro.

DON is commonly found in foods and feeds; it presents health risks, especially an increase of growth inhibition in humans, particularly infants and young children. However, there are relatively few research studies devoted to the mechanism of DON-mediated growth retardation. Interestingly, our results showed that DON does not cause any significant production of ROS but results in a persistent and significant release of NO with iNOS increasing activity, mitochondrial ultrastructural changes and decreasing ΔΨm. Moreover, the significant decreases in GH production and secretion induced by DON were dose-dependent, accompanied by an increase of caspase 3, 8 and 9, IL-11, IL-lß and GHRH. NO scavenging agent (haemoglobin) and free radical scavenging agent (N-acetylcysteine) partially reversed mitochondrial damage, and Z-VAD-FMK increased the levels of GH and decreased the levels of caspase 3, 8 and 9, while haemoglobin decreased the levels of caspase 3, 8 and 9, indicating that NO is the primary target of DON-mediated inhibition. Present research study firstly demonstrated that NO is a key mediator of DON-induced growth inhibition and plays critical roles in the interference of GH transcription and synthesis. The current research is conducive to future research on the molecular mechanisms of DON-induced growth inhibition in humans, especially children.

Brown marine algae Gongolaria baccata extract protects Caco-2 cells from oxidative stress induced by tert-butyl hydroperoxide.

Gongolaria baccata (S.G. Gmelin) is marine brown seaweed mainly found on the coasts of the Baltic Sea south to the Mediterranean Sea, Canary Islands, Mauritania and Western Sahara. Herein, we report the cell viability and protective effects attributed to molecular mechanisms underlying antioxidant response to survive oxidative stress injuries. Caco-2 cells were submitted to oxidative stress by treatment with tert-butylhydroperoxide (tert-BOOH). The extract prevented cell damage and enhanced activity of antioxidant defenses (NQO1 and GST activities and GSH levels) reduced by treatment with tert-BOOH. The increases of MDA levels, the amount of intracellular ROS and caspase 3/7 activity induced by tert-BOOH were prevented when cells were treated with the G. baccata extract. Moreover, G. baccata extract caused up-regulation of GSTM2, Nrf2, and AKT1 gene expressions, as well as G. baccata extract reduced significantly Bax, BNIP3, APAF1, ERK1, JNK1, MAPK1, P38, P53, NFκB1, TNFα, IL-6, IL-1ß and HO-1 gene expressions related to apoptosis, proinflammation and oxidative stress induced by tert-BOOH. These results suggest that G.baccata extract protected the cells against oxidative damage and inflammation; protective effects that could be linked to their bioactive constituents. Hence, this brown seaweed G.baccata extract could be used for the development of functional foods and/or nutraceuticals.