Methylene blue and monosodium glutamate improve neurologic signs after fluoroacetate poisoning

Extensive evaluation of a new LC-MS-MS method to quantify monofluoroacetate toxin in the kidney

Monofluoroacetate is a highly lethal toxin that causes death by inhibiting cellular adenosine triphosphate (ATP) production. The heart and brain are the primary target organs. Acute death is attributed to cardiac fibrillation and/or convulsions. Although it occurs naturally in some plants, a major source of animal intoxication is access to sodium monofluoroacetate (NaMFA) pesticide, which continues to be a concern in the USA and around the world despite restricted use in some countries including the USA. There are also concerns about misuse of this pesticide for malicious poisoning. Currently, a tissue-based diagnostic method for NaMFA intoxication in animals is lacking. There is a critical need by the veterinary diagnostic community for a simple, sensitive and reliable tissue-based diagnostic test to confirm NaMFA poisoning in animals. We have developed and extensively evaluated a sensitive novel liquid chromatography combined with tandem mass spectrometry method suitable for this purpose. The limits of detection and limits of quantitation are 1.7 and 5.0 ng/g, respectively. The accuracy and precision met or exceeded expectations. The method performance was verified using the incurred kidney obtained from animal diagnostic cases. This novel kidney-based method is now available for clinical use and can help with diagnostic purposes, including detecting potential issues related to animal foods.

Danshensu methyl ester attenuated LPS-induced acute lung injury by inhibiting TLR4/NF-κB pathway

Acute Lung Injury (ALI) manifests as an acute exacerbation of pulmonary inflammation with high mortality. The potential application of Danshensu methyl ester (DME, synthesized in our lab) in ameliorating ALI has not been elucidated. Our results demonstrated that DME led to a remarkable reduction in lung injury. DME promoted a marked increase in antioxidant enzymes, like superoxide dismutase (SOD), and glutathione (GSH), accompanied by a substantial decrease in reactive oxygen species (ROS), myeloperoxidase (MPO), and malondialdehyde (MDA). Moreover, DME decreased the production of IL-1β, TNF-α and IL-6, in vitro and in vivo. TLR4 and MyD88 expression is reduced in the DME-treated cells or tissues, which further leading to a decrease of p-p65 and p-IκBα. Meanwhile, DME effectively facilitated an elevation in cytoplasmic p65 expression. In summary, DME could ameliorate ALI by its antioxidant functionality and anti-inflammation effects through TLR4/NF-κB, which implied that DME may be a viable medicine for lung injury.

Succinate prodrugs as treatment for acute metabolic crisis during fluoroacetate intoxication in the rat

Sodium fluoroacetate (FA) is a metabolic poison that systemically inhibits the tricarboxylic acid (TCA) cycle, causing energy deficiency and ultimately multi-organ failure. It poses a significant threat to society because of its high toxicity, potential use as a chemical weapon and lack of effective antidotal therapy. In this study, we investigated cell-permeable succinate prodrugs as potential treatment for acute FA intoxication. We hypothesized that succinate prodrugs would bypass FA-induced mitochondrial dysfunction, provide metabolic support, and prevent metabolic crisis during acute FA intoxication. To test this hypothesis, rats were exposed to FA (0.75 mg/kg) and treated with the succinate prodrug candidate NV354. Treatment efficacy was evaluated based on cardiac and cerebral mitochondrial respiration, mitochondrial content, metabolic profiles and tissue pathology. In the heart, FA increased concentrations of the TCA metabolite citrate (+ 4.2-fold, p < 0.01) and lowered ATP levels (- 1.9-fold, p < 0.001), confirming the inhibition of the TCA cycle by FA. High-resolution respirometry of cardiac mitochondria further revealed an impairment of mitochondrial complex V (CV)-linked metabolism, as evident by a reduced phosphorylation system control ratio (- 41%, p < 0.05). The inhibition of CV-linked metabolism is a novel mechanism of FA cardiac toxicity, which has implications for drug development and which NV354 was unable to counteract at the given dose. In the brain, FA induced the accumulation of β-hydroxybutyrate (+ 1.4-fold, p < 0.05) and the reduction of mitochondrial complex I (CI)-linked oxidative phosphorylation (OXPHOSCI) (- 20%, p < 0.01), the latter of which was successfully alleviated by NV354. This promising effect of NV354 warrants further investigations to determine its potential neuroprotective effects.

Construction and Enhanced Efficiency of Bi2MoO6/ZnO Compo-Sites for Visible-Light-Driven Photocatalytic Performance

Bi₂MoO₆ was one of the important bismuth-based semiconductors with a narrow bandgap, and has been widely used in selective oxidation catalysts, supercapacitors, and energy-storage devices. A series of Bi₂MoO₆/ZnO composite photocatalysts with different mass ratios were synthesized by the hydrothermal method. The synthesized samples were characterized by XRD, PL, UV-Vis, SEM, TEM, XPS, and BET analysis techniques. Under visible light conditions, Methylene blue (MB) was used as the target degradation product to evaluate its photocatalytic performance. The results showed that the degradation rate constant of Bi₂MoO₆/ZnO (0.4-BZO) was about twice that of the traditional photocatalysis of ZnO. The Bi₂MoO₆/ZnO composite catalyst maintained stable performance after four consecutive runs. The high photocatalytic activity of Bi₂MoO₆/ZnO was attributed to the efficient electron transport of the heterojunction, which accelerates the separation of electron-hole pairs and reduces the probability of carrier recombination near the Bi₂MoO₆/ZnO heterojunction. Bi₂MoO₆/ZnO nanocomposites have potential applications in the field of photodegradation.

Role of pyroptosis in diabetic retinopathy and its therapeutic implications

Pyroptosis has recently been established as a term of programmed-inflammatory cell death. Pyroptosis is mainly divided into two molecular signaling pathways, including caspase-1-dependent canonical and caspase-4/5/11-dependent non-canonical inflammasome pathways. Extensive investigations have reported inflammasome activation facilitates the maturation and secretion of the inflammatory factors interleukin-1β/18 (IL-1β/18), cleavage of gasdermin D (GSDMD), and leading to the stimulation of pyroptosis-mediated cell death. Furthermore, accumulating studies report NLRP3 inflammasome activation plays a significant role in triggering the pyroptosis-mediated cell death and promotes the pathogenesis of diabetic retinopathy (DR). Our current review elaborates on the molecular mechanisms of pyroptosis-signaling pathways and their potential roles in the pathogenesis and impact of DR development. We also emphasize several investigational molecules regulating key steps in pyroptotic-cell death to create new comprehensions and findings to explore the pathogenesis of DR advancement. Our narrative review concisely suggests these potential pharmacological agents could be promising therapies to treat and manage DR in the future.