First-in-human study assessing safety, tolerability, and pharmacokinetics of 2-hydroxybenzylamine acetate, a selective dicarbonyl electrophile scavenger, in healthy volunteers

Immune Mechanisms in Hypertension

It is now apparent that immune mediators including complement, cytokines, and cells of the innate and adaptive immune system contribute not only to blood pressure elevation but also to the target organ damage that occurs in response to stimuli like high salt, aldosterone, angiotensin II, and sympathetic outflow. Alterations of vascular hemodynamic factors, including microvascular pulsatility and shear forces, lead to vascular release of mediators that affect myeloid cells to become potent antigen-presenting cells and promote T-cell activation. Research in the past 2 decades has defined specific biochemical and molecular pathways that are engaged by these stimuli and an emerging paradigm is these not only lead to immune activation, but that products of immune cells, including cytokines, reactive oxygen species, and metalloproteinases act on target cells to further raise blood pressure in a feed-forward fashion. In this review, we will discuss these molecular and pathophysiological events and discuss clinical interventions that might prove effective in quelling this inflammatory process in hypertension and related cardiovascular diseases.

Edible wild plants, chicory and purslane, alleviated diabetic testicular dysfunction, and insulin resistance via suppression 8OHdg and oxidative stress in rats

Testicular dysfunction is a prevalent health problem frequently reported in individuals with diabetes mellitus (DM). Oxidative-inflammatory reactions, hormonal and spermatic abnormalities often accompany this illness. Herbal remedies "particularly wild plants" including chicory (Chicorium Intybus) and purslane (Portulaca Oleracea) are emerging as popular agents for people dealing with these issues due to their ability to act as antioxidants, reduce inflammation, and exhibit antidiabetic effects. According to the collected data, the daily administration of chicory (Ch) seed-extract (250 mg/kg) or purslane (Pu) seed-extract (200 mg/kg) to streptozotocin (STZ)-induced diabetic rats (50 mg/kg) for 30 days resulted in the normalization of fasting blood glucose (FBG), serum fructosamine, insulin levels, and insulin resistance (HOMA-IR), as well as reducing lipid peroxidation end-product malondialdehyde (MDA) level, aldehyde oxidase (AO) and xanthene oxidase (XO) activities. While caused a considerable improvement in glutathione (GSH) content, superoxide dismutase (SOD), catalase (CAT) activity, and total antioxidant capacity (TAC) when compared to diabetic rats. Ch and Pu extracts had a substantial impact on testicular parameters including sperm characterization, testosterone level, vimentin expression along with improvements in body and testis weight. They also mitigated hyperlipidemia by reducing total lipids (TL), total cholesterol (TC) levels, and low-density lipoprotein cholesterol (LDL-C), while increasing high-density lipoprotein cholesterol (HDL-C). Furthermore, oral administration of either Ch or Pu notably attuned the elevated proinflammatory cytokines as tumor necrotic factor (TNF-α), C-reactive protein (CRP), and Interleukin-6 (IL-6) together with reducing apoptosis and DNA damage. This was achieved through the suppression of DNA-fragmentation marker 8OHdG, triggering of caspase-3 immuno-expression, and elevation of Bcl-2 protein. The histological studies provided evidence supporting the preventive effects of Ch and Pu against DM-induced testicular dysfunction. In conclusion, Ch and Pu seed-extracts mitigate testicular impairment during DM due to their antihyperglycemic, antilipidemic, antioxidant, anti-inflammatory, and antiapoptotic properties.

The pursuit of accurate predictive models of the bioactivity of small molecules

Property prediction is a key interest in chemistry. For several decades there has been a continued and incremental development of mathematical models to predict properties. As more data is generated and accumulated, there seems to be more areas of opportunity to develop models with increased accuracy. The same is true if one considers the large developments in machine and deep learning models. However, along with the same areas of opportunity and development, issues and challenges remain and, with more data, new challenges emerge such as the quality and quantity and reliability of the data, and model reproducibility. Herein, we discuss the status of the accuracy of predictive models and present the authors' perspective of the direction of the field, emphasizing on good practices. We focus on predictive models of bioactive properties of small molecules relevant for drug discovery, agrochemical, food chemistry, natural product research, and related fields.

Anti-ulcer effect of Ranunculus millefoliatus on absolute alcohol-induced stomach ulceration

Ranunculus millefoliatus (RM) has been reported to have a numeral of biological properties. Though, the influence of this plant extract on stomach ulceration is yet stated. Thirty rats arbitrarily alienated 5 groups: the normal group, the ulcerated control group, the omeprazole group, and 2 investigational groups. Normal and ulcerated control groups were gavage by mouth 10% Tween 20. Omeprazole group fed orally 20 mg/kg omeprazole. Investigational group's gavage of 250 mg/kg and 500 mg/kg ethanol extracted RM 10% Tween 20, correspondingly. Later another hour, the normal group gavage 10% Tween 20, and groups 2-5 gavage absolute ethanol. Afterward additional hours altogether rats were sacrificed. The ulcerated control group displayed extensive apparent stomach epithelial damage escorted by reduced stomachs mucus excretion and pH stomach contented. RM extract meaningfully condensed ethanol-induced gastric lacerations, for example, demonstrated via augmented gastric mucus and pH stomach contents, condensed ulceration expanse, decreased or lack of edema, and leucocyte penetration hypodermic coat. In stomach epithelial homogenate, RM extract revealed important upsurge superoxide dismutase (SOD), catalase (CAT) actions, expressively diminished malondialdehyde (MDA) level. Furthermore, RM extract augmented strength periodic acid-Schiff (PAS) stain stomach mucosa, besides formed up-regulation heat shock protein 70 (HSP 70) proteins down-regulation the Bcl-2-associated X protein (Bax) protein gastric mucosal. RM extract lessened the level of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and improved the quantity of interleukin-10 (IL-10). Acute toxicity greater dosage of 500 mg/kg RM extract organized not obvious at all toxicology symbols might improve self-protective tools against stomach epithelial abrasions. RM extract presented gastroprotective effects that could be due to capability upsurge pH then mucus discharge, rise SOD and CAT, decrease MDA quantity, up-regulating HSP 70 proteins, down-regulating Bax protein, and moderate provocative cytokines.

Inflammation Biomarker Response to Oral 2-Hydroxybenzylamine (2-HOBA) Acetate in Healthy Humans

Inflammation is associated with the formation of reactive oxygen species (ROS) and the formation of lipid-derived compounds, such as isolevuglandins (IsoLGs), malondialdehyde, 4-hydroxy-nonenal, and 4-oxo-nonenal. The most reactive of these are the IsoLGs, which form covalent adducts with lysine residues and other cellular primary amines leading to changes in protein function, immunogenicity, and epigenetic alterations and have been shown to contribute to a number of inflammatory diseases. 2-Hydroxybenzylamine (2-HOBA) is a natural compound found in buckwheat seeds and reacts with all IsoLG adducts preventing adduct formation with proteins and DNA. Therefore, 2-HOBA is well positioned as an agent for the prevention of inflammatory-prone diseases. In this study, we examined the potential beneficial effects of 2-HOBA on oxidative stress and inflammatory biomarkers in two cohorts of healthy younger and older adults. We utilized the Olink® targeted inflammation panel before and after an oral 15-day treatment regimen with 2-HOBA. We found significant relative changes in the plasma concentration of 15 immune proteins that may reflect the in vivo immune targets of 2-HOBA. Treatment of 2-HOBA resulted in significant increased levels of CCL19, IL-12β, IL-20Rα, and TNFβ, whereas levels of TWEAK significantly decreased. Ingenuity Pathway Analysis identified canonical pathways regulated by the differentially secreted cytokines, chemokines, and growth factors upon 2-HOBA treatment and further points to biofunctions related to the recruitment, attraction, and movement of different immune cell types. In conclusion, 2-HOBA significantly altered the protein biomarkers CCL19, IL-12β, IL-20Rα, TNFβ, and TWEAK, and these may be responsible for the protective effects of 2-HOBA against reactive electrophiles, such as IsoLGs, commonly expressed in conditions of excessive oxidative stress. 2-HOBA has a role as a IsoLG scavenger to proactively improve immune health in a variety of conditions.

Quality of veterinary anthelmintic drugs marketed in Gondar Zones, North West Ethiopia; presence of poor-quality medicines

The presence of poor-quality veterinary drugs hampers the effectiveness of animal health care systems. It may produce danger to human safety through animal-derived food products that are consumed by the people. Thus, this study assessed the quality of veterinary albendazole, fenbendazole and ivermectin boluses/tablets marketed in Gondar Zones, North West Ethiopia. A total of 42 samples were collected from all government veterinary clinics and private veterinary pharmacies in Gondar zones by mystery shoppers from October, 2020 to January, 2021. All samples were visually and physically inspected for proper labeling and packaging. Samples were evaluated based on Pharmacopoeias and manufacturers' methods for identification, assay, dosage uniformity, dissolution, disintegration, hardness, and friability tests. All samples passed the visual inspection criteria outlined in the joint WHO/FIP/USP checklist. In general, 80.95% (34/42) of the products examined were substandard failing one or more quality test parameters, including all albendazole (30/30) and fenbendazole (4/4) samples. However, all of the ivermectin samples (8/8) passed the quality test parameters investigated in this work. The study had indicated that low quality veterinary albendazole and fenbendazole products are incredibly common in the study sites. The most crucial quality features investigated as failure were friability and disintegration. Thus, regulations and enforcements that guarantee quality of veterinary anthelminthic medications should be strictly in place in the study area and in the country.

Electrophilic reactive aldehydes as a therapeutic target in colorectal cancer prevention and treatment

Colorectal cancer (CRC) is a major health problem worldwide. Dicarbonyl electrophiles, such as isolevuglandins (isoLGs), are generated from lipid peroxidation and form covalent adducts with amine-containing macromolecules. We have shown high levels of adducts of isoLGs in colonic epithelial cells of patients with CRC. We thus investigated the role of these reactive aldehydes in colorectal cancer development. We found that 2-hydroxybenzylamine (2-HOBA), a natural compound derived from buckwheat seeds that acts as a potent scavenger of electrophiles, is bioavailable in the colon of mice after supplementation in the drinking water and does not affect the colonic microbiome. 2-HOBA reduced the level of isoLG adducts to lysine as well as tumorigenesis in models of colitis-associated carcinogenesis and of sporadic CRC driven by specific deletion of the adenomatous polyposis coli gene in colonic epithelial cells. In parallel, we found that oncogenic NRF2 activation and signaling were decreased in the colon of 2-HOBA-treated mice. Additionally, the growth of xenografted human HCT116 CRC cells in nude mice was significantly attenuated by 2-HOBA supplementation. In conclusion, 2-HOBA represents a promising natural compound for the prevention and treatment of CRC.

The nutraceutical electrophile scavenger 2-hydroxybenzylamine (2-HOBA) attenuates gastric cancer development caused by Helicobacter pylori

Stomach cancer is a leading cause of cancer death. Helicobacter pylori is a bacterial gastric pathogen that is the primary risk factor for carcinogenesis, associated with its induction of inflammation and DNA damage. Dicarbonyl electrophiles are generated from lipid peroxidation during the inflammatory response and form covalent adducts with amine-containing macromolecules. 2-hydroxybenzylamine (2-HOBA) is a natural compound derived from buckwheat seeds and acts as a potent scavenger of reactive aldehydes. Our goal was to investigate the effect of 2-HOBA on the pathogenesis of H. pylori infection. We used transgenic FVB/N insulin-gastrin (INS-GAS) mice as a model of gastric cancer. First, we found that 2-HOBA is bioavailable in the gastric tissues of these mice after supplementation in the drinking water. Moreover, 2-HOBA reduced the development of gastritis in H. pylori-infected INS-GAS mice without affecting the bacterial colonization level in the stomach. Further, we show that the development of gastric dysplasia and carcinoma was significantly reduced by 2-HOBA. Concomitantly, DNA damage were also inhibited by 2-HOBA treatment in H. pylori-infected mice. In parallel, DNA damage was inhibited by 2-HOBA in H. pylori-infected gastric epithelial cells in vitro. In conclusion, 2-HOBA, which has been shown to be safe in human clinical trials, represents a promising nutritional compound for the chemoprevention of the more severe effects of H. pylori infection.

Supervised chemical graph mining improves drug-induced liver injury prediction

Drug-induced liver injury (DILI) is the main cause of drug failure in clinical trials. The characterization of toxic compounds in terms of chemical structure is important because compounds can be metabolized to toxic substances in the liver. Traditional machine learning approaches have had limited success in predicting DILI, and emerging deep graph neural network (GNN) models are yet powerful enough to predict DILI. In this study, we developed a completely different approach, supervised subgraph mining (SSM), a strategy to mine explicit subgraph features by iteratively updating individual graph transitions to maximize DILI fidelity. Our method outperformed previous methods including state-of-the-art GNN tools in classifying DILI on two different datasets: DILIst and TDC-benchmark. We also combined the subgraph features by using SMARTS-based frequent structural pattern matching and associated them with drugs' ATC code.

Inhibitory effect of phenolic extract from squirting cucumber (Ecballium elaterium (L.) A. Rich) seed oil on integrin-mediated cell adhesion, migration and angiogenesis

Integrin targeted therapies by natural bioactive compounds have attracted attention in the field of oncology and cancer treatment. This study evaluates the potential of phenolic extract from the medicinal herb Ecballium elaterium L. seed oil (PEO) to inhibit the adhesion and migration of the highly invasive human fibrosarcoma cell line HT1080. At safe concentrations (up to 40 μg mL-1), results show that PEO dose-dependently inhibits adhesion and migration of HT1080 to fibronectin (IC50 = 18 μg mL-1) and fibrinogen (IC50 = 12.86 μg mL-1). These observations were associated with the reduction of cell motility and migration velocity as revealed in the Boyden chamber and random motility using two-dimensional assays, respectively. Additional experiments using integrin blocking antibodies showed that PEO at the highest safe concentration (40 μg mL-1) competitively inhibited the attachment of HT1080 cell to anti-αvβ3 (>98%), anti-α5β1 (>86%), and to a lesser extent anti-α2 (>50%) immobilized antibodies, suggesting that αvβ3 and α5β1 integrins were selectively targeted by PEO. Moreover, PEO specifically targeted these integrins in human microvascular endothelial cells (HMEC-1) and dose-dependently blocked the in vitro tubulogenesis. In the CAM model, PEO inhibited the VEGF-induced neoangiogenesis confirming its anti-angiogenic effect. Collectively, these results indicate that PEO holds promise for the development of natural integrin-targeted therapies against fibrosarcoma.

IsoLGs (Isolevuglandins) Drive Neutrophil Migration in Hypertension and Are Essential for the Formation of Neutrophil Extracellular Traps

BACKGROUND

IsoLGs (isolevuglandins) are electrophilic products of lipid peroxidation formed in the presence of reactive oxygen species. IsoLGs contribute to hypertension by an unknown mechanism. Studies have shown that reactive oxygen species production drives the formation of neutrophil extracellular traps (NETs) and that NETs accumulate within the aorta and kidneys of patients with hypertension. The purpose of this study was to determine the role of isoLGs in neutrophil migration and NET formation (NETosis) in hypertension.

METHODS

Mice were treated with Ang II (angiotensin II) and the specific isoLG scavenger 2-hydroxybenzylamine and examined for tissue neutrophil and NET accumulation by single-cell sequencing and flow cytometry. Isolated human neutrophils were studied to determine the role of isoLGs in NETosis and neutrophil chromatin expansion by immunofluorescence and live cell confocal microscopy.

RESULTS

Single-cell sequencing performed on sham, Ang II, and Ang II+2-hydroxybenzylamine treated mice revealed neutrophils as a primary target of 2-hydroxybenzylamine. Peripheral neutrophil migration, aortic NET accumulation, and renal NET accumulation is blocked with 2-hydroxybenzylamine treatment. In isolated human neutrophils, isoLGs accumulate during NETosis and scavenging of isoLGs prevents NETosis. IsoLGs drive neutrophil chromatin expansion during NETosis and disrupt nucleosome structure.

CONCLUSIONS

These observations identified a critical role of isoLGs in neutrophil migration and NETosis in hypertension and provide a potential therapy for NET-associated diseases including hypertension and associated end organ damage.

Isolevuglandins disrupt PU.1-mediated C1q expression and promote autoimmunity and hypertension in systemic lupus erythematosus

We describe a mechanism responsible for systemic lupus erythematosus (SLE). In humans with SLE and in 2 SLE murine models, there was marked enrichment of isolevuglandin-adducted proteins (isoLG adducts) in monocytes and dendritic cells. We found that antibodies formed against isoLG adducts in both SLE-prone mice and humans with SLE. In addition, isoLG ligation of the transcription factor PU.1 at a critical DNA binding site markedly reduced transcription of all C1q subunits. Treatment of SLE-prone mice with the specific isoLG scavenger 2-hydroxybenzylamine (2-HOBA) ameliorated parameters of autoimmunity, including plasma cell expansion, circulating IgG levels, and anti-dsDNA antibody titers. 2-HOBA also lowered blood pressure, attenuated renal injury, and reduced inflammatory gene expression uniquely in C1q-expressing dendritic cells. Thus, isoLG adducts play an essential role in the genesis and maintenance of systemic autoimmunity and hypertension in SLE.

Blood serum levels of selected biomarkers of oxidative stress among printing workers occupationally exposed to low-levels of toluene and xylene

Printing workers (PWs) are exposed to a mixture of solvents, yet the health risks associated with such exposuer are unknown. This study aimed to compare the serum levels of selected biomarkers of oxidative stress among occupationally exposed PWs to low-level of toluene and xylenes and unexposed controls. Associations between levels of such biomarkers and occupational exposures to toluene and xylene were also investigated. Urinary levels of hippuric acid (HA) and methyl hippuric acids (MHAs) as exposure biomarkers of toluene and xylenes, respectively, and serum levels of oxidative stress biomarkers, including total antioxidant capacity (TAC), malondialdehyde (MDA), and the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), were measured among the 84 subjects, comprising 44 PWs and 40 unexposed subjects. Mean concentrations of urinary HA and MHAs of PWs showed a significant increase compared with the unexposed controls. Although levels of urinary biomarkers of exposure to toluene (HA) and xylenes (MHAs) were well below the biological exposure indices (BEIs; ACGHI), PWs presented significantly increased serum levels of MDA, and significantly decreased serum activities of SOD and GPx compared to the unexposed controls. However, for serum TAC and CAT activity, no significant difference was observed between the two groups. Correlation analyses indicated that urinary levels of HA and MHAs were positively correlated with MDA levels and negatively correlated with GPx and SOD. Our study suggested that the alterations evidenced in serum levels of MDA, SOD, and GPx could be involved in the oxidative stress caused by co-exposure to low levels of toluene and xylene. Further investigation is needed to clarify the effect of low-level occupational exposure to solvents among PWs.

Novel chalcone-derived pyrazoles as potential therapeutic agents for the treatment of non-small cell lung cancer

Lung cancer is considered to account for approximately one-fifth of all malignant tumor-related deaths worldwide and is therefore one of the most lethal malignancies. Pyrazole scaffold possesses a wide range of biological and pharmacological activities, which play important roles in medicinal chemistry. The present study reports the synthesis and in vitro biological characterization of nine pyrazoles derived from chalcones as potential anticancer agents for non-small cell lung cancer A-549, H226, and H460 cell lines. Most of the compounds efficiently inhibited the growth of all the tested cancer cell lines at micromolar concentrations. One of the most active compounds (PCH-1) was further evaluated for its effect on cell cycle distribution, apoptosis, migration, epithelial–mesenchymal transition, and oxidative stress. Furthermore, studies on the mechanism of action revealed that PCH-1 disrupts microtubule assembly, leading to cancer cell death. Molecular modeling studies confirmed the potent interaction of PCH-1 with the vinblastine binding site on tubulin. Overall, this study provides novel opportunities to identify anticancer agents in the pyrazole series.

Susceptibility of Lung Carcinoma Cells to Nanostructured Lipid Carrier of ARV-825, a BRD4 Degrading Proteolysis Targeting Chimera

The present work was aimed at developing an optimized and modified nanostructured lipid carrier of BRD4 protein degrading Proteolysis Targeting Chimera (PROTAC) against non-small cell lung carcinoma. PROTACs are an emerging class of anticancer molecules with nanomolar activity but associated with significant solubility challenges. Lipid-based colloidal systems like nanostructured lipid carriers are widely explored for such highly lipophilic molecules. ARV-825, a cereblon-based PROTAC was investigated for its anticancer efficacy in vitro in 2D and 3D lung cancer models. ARV-825 loaded PEGylated nanostructured lipid carriers (AP-NLC) was prepared using melt emulsification technique. ARV-825 was stabilized using Precirol® ATO5 and Captex® 300 EP/NF as the solid and liquid lipid, respectively. However, hydrophobic ion-pairing with medium chain fatty acid was required to improve drug loading and stability. A hydrodynamic diameter and polydispersity index of 56.33 ± 0.42 nm and 0.16 respectively with zeta potential of -21 ± 1.24 mV was observed. In vitro migration and colony formation assay confirmed the anticancer activity of ARV-825 alone and AP-NLC. Nearly 38% and 50% apoptotic cell population were observed after ARV-825 and AP-NLC treatment. Immunoblotting assay showed complete suppression of BRD4 and c-Myc protein expression for AP-NLC. Most importantly, significant reduction in the growth of multicellular 3D spheroid of A549 cells confirmed the effectiveness of BRD4 PROTAC and its lipid nanoparticle in non-small cell lung cancer (NSCLC). AP-NLC. Higher amount of red fluorescence throughout the spheroid surface further confirmed superior efficacy of AP-NLC in tumor penetration and cell killing.

Emerging Anti-Atherosclerotic Therapies

Cardiovascular disease (CAD) is the main cause of morbidity and deaths in the western world. The development of atherosclerosis underlying CAD development begins early in human life. There are numerous genetic and environmental risk factors accelerating its progression which then leads to the occurrence of acute events. Despite considerable progress in determining risk factors, there is still a lot of work ahead since identified determinants are responsible only for a part of overall CAD risk. Current therapies are insufficient to successfully reduce the risk of atherosclerosis development. Therefore, there is a need for effective preventive measures of clinical manifestations of atherosclerosis since the currently available drugs cannot prevent the occurrence of even 70% of clinical events. The shift of the target from lipid metabolism has opened the door to many new therapeutic targets. Currently, the majority of known targets for anti-atherosclerotic drugs focus also on inflammation (a common mediator of many risk factors), mechanisms of innate and adaptive immunity in atherosclerosis, molecule scavengers, etc. The therapeutic potential of cyclodextrins, protein kinase inhibitors, colchicine, inhibitors of p38 mitogen-activated protein kinase (MAPK), lipid dicarbonyl scavengers, a monoclonal antibody targeting interleukin-1β, and P-selectin inhibitors is still not fully confirmed and requires confirmation in large clinical trials. The preliminary results look promising.

2-Hydroxybenzylamine (2-HOBA) to prevent early recurrence of atrial fibrillation after catheter ablation: protocol for a randomized controlled trial including detection of AF using a wearable device

Background

Although catheter ablation is an effective therapy for atrial fibrillation (AF), the most common cardiac arrhythmia encountered in clinical practice, AF ablation generates inflammation and oxidative stress in the early postoperative period predisposing to recurrence of AF. Isolevuglandins (IsoLGs) are reactive lipid mediators of oxidative stress injury that rapidly react with endogenous biomolecules to compromise their function. 2-Hydroxybenzylamine (2-HOBA), a potent small molecule scavenger of IsoLGs, sequesters the reactive species as inert adducts. This mechanism, coupled with reported safety in humans, supports the investigation of 2-HOBA as a novel therapeutic to reduce AF caused by oxidative stress, such as that which occurs after catheter ablation. Accordingly, we seek to test the hypothesis that treatment with 2-HOBA will decrease early recurrence of AF and other atrial arrhythmias following AF ablation by decreasing IsoLG adducts with native biomolecules.

Methods

The proposed trial will randomly assign 162 participants undergoing cryo- or radiofrequency catheter ablation for AF to 2-HOBA (N = 81) or placebo (N = 81). Individuals will begin the study drug 3 days prior to ablation and continue for 28 days. Participants will be given a wearable smartwatch capable of detecting and recording atrial arrhythmias. They will be instructed to record ECGs daily with additional ECGs if they experience symptoms of AF or when alerted by the smartwatch AF detection alarm. The primary clinical endpoint will be an episode of AF, atrial tachycardia, or atrial flutter lasting 30 s or more within 28 days post-AF ablation. Secondary measures will be the change in IsoLG adduct levels from blood samples collected immediately pre-ablation and post-ablation and reduction in AF burden as calculated from the smartwatch.

Discussion

The proposed trial will test the hypothesis that 2-HOBA reduces post-ablation atrial arrhythmias through sequestration of reactive IsoLG species. The results of this study may improve the understanding of the role of IsoLGs and oxidative stress in AF pathogenesis and provide evidence to advance 2-HOBA and related compounds as a new therapeutic strategy to treat AF.

Trial registration

ClinicalTrials.gov NCT04433091. Registered on June 3, 2020.

Synthesis of new 2-aminothiazolyl/benzothiazolyl-based 3,4-dihydropyrimidinones and evaluation of their effects on adenocarcinoma gastric cell migration

Gastric cancer is one of the malignant tumors of the gastrointestinal tract that, despite its decrease in recent years, is still the fourth most common cancer and the second leading cause of cancer-related death. Various strategies including chemotherapy are used to keep cancer cells from spreading and induce apoptotic death in them. Recent studies have shown that dihydropyrimidinones (DHPMs) are privileged structures in medicinal chemistry due to their pharmacological effects. A number of new 2-aminothiazolyl/benzothiazolyl derivatives of 3,4-DHPMs (3-8) were synthesized and structurally identified, and then their effects on the migration behavior of human AGS cells (gastric cancer cells) were investigated. Molecular docking and molecular dynamics (MD) simulations were applied to explore binding potential and realistic binding model of the assessed derivatives through identification of key amino acid residues within L5/α2/α3 allosteric site of kinesin 5 (Eg5) as a validated microtubule-dependent target for monastrol as a privileged DHPM derivative.

Isolevuglandins (isoLGs) as toxic lipid peroxidation byproducts and their pathogenetic role in human diseases

Lipid peroxidation results in generation of a variety of lipid hydroperoxides and other highly reactive species that covalently modify proteins, nucleic acids, and other lipids, thus resulting in lipotoxicity. Although biological relevance of 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA) is well studied, the existing data on the role of isolevuglandins (isoLGs) in pathology are insufficient. Therefore, the objective of the present study was to review the existing data on biological effects of isoLG and isoLG adducts and their role in multiple diseases. Sixty four highly reactive levuglandin-like γ-ketoaldehyde (γ-KA, or isoketals, IsoK, or isolevuglandins, IsoLG) regio- and stereo-isomers are formed as products of arachidonic acid oxidation. IsoLGs react covalently with lysyl residues of proteins to form a stable adduct and intramolecular aminal, bispyrrole, and trispyrrole cross-links. Phosphatidylethanolamine was also shown to be the target for isoLG binding as compared to proteins and DNA. Free IsoLGs are not detectable in vivo, although isolevuglandin adduction to amino acid residues of particular proteins may be evaluated with liquid chromatography-tandem mass spectrometry. Adducts formed were shown to play a significant role in the development and maintenance of oxidative stress, endoplasmic reticulum stress, mitochondrial dysfunction, and inflammation. These, and more specific molecular pathways, link isoLG and isoLG-adduct formation to develop a variety of pathologies, including cardiovascular diseases (atherosclerosis, hypertension, heart failure), obesity and diabetes, cancer, neurodegeneration, eye diseases (retinal degeneration and glaucoma), as well as ageing. Hypothetically, isoLGs and isoLG adduct formation may be considered as the potential target for treatment of oxidative stress-related diseases.

Scavenging Reactive Lipids to Prevent Oxidative Injury

Oxidative injury due to elevated levels of reactive oxygen species is implicated in cardiovascular diseases, Alzheimer's disease, lung and liver diseases, and many cancers. Antioxidant therapies have generally been ineffective at treating these diseases, potentially due to ineffective doses but also due to interference with critical host defense and signaling processes. Therefore, alternative strategies to prevent oxidative injury are needed. Elevated levels of reactive oxygen species induce lipid peroxidation, generating reactive lipid dicarbonyls. These lipid oxidation products may be the most salient mediators of oxidative injury, as they cause cellular and organ dysfunction by adducting to proteins, lipids, and DNA. Small-molecule compounds have been developed in the past decade to selectively and effectively scavenge these reactive lipid dicarbonyls. This review outlines evidence supporting the role of lipid dicarbonyls in disease pathogenesis, as well as preclinical data supporting the efficacy of novel dicarbonyl scavengers in treating or preventing disease.

Scavenging of reactive dicarbonyls with 2-hydroxybenzylamine reduces atherosclerosis in hypercholesterolemic Ldlr-/- mice

Lipid peroxidation generates reactive dicarbonyls including isolevuglandins (IsoLGs) and malondialdehyde (MDA) that covalently modify proteins. Humans with familial hypercholesterolemia (FH) have increased lipoprotein dicarbonyl adducts and dysfunctional HDL. We investigate the impact of the dicarbonyl scavenger, 2-hydroxybenzylamine (2-HOBA) on HDL function and atherosclerosis in Ldlr^−/− mice, a model of FH. Compared to hypercholesterolemic Ldlr^−/− mice treated with vehicle or 4-HOBA, a nonreactive analogue, 2-HOBA decreases atherosclerosis by 60% in en face aortas, without changing plasma cholesterol. Ldlr^−/− mice treated with 2-HOBA have reduced MDA-LDL and MDA-HDL levels, and their HDL display increased capacity to reduce macrophage cholesterol. Importantly, 2-HOBA reduces the MDA- and IsoLG-lysyl content in atherosclerotic aortas versus 4-HOBA. Furthermore, 2-HOBA reduces inflammation and plaque apoptotic cells and promotes efferocytosis and features of stable plaques. Dicarbonyl scavenging with 2-HOBA has multiple atheroprotective effects in a murine FH model, supporting its potential as a therapeutic approach for atherosclerotic cardiovascular disease.

Hypercholesterolemia is associated with lipid peroxidation induced reactive dicarbonyl adducts. Here the authors show that the dicarbonyl scavenger, 2-hydroxybenzylamine(2-HOBA), decreases reactive dicarbonyl modifications of LDL and HDL, improves HDL function, reduces atherosclerosis and promotes features of stable plaques in a mouse model of hypercholestrolemia.

Safety, tolerability, and pharmacokinetics of repeated oral doses of 2-hydroxybenzylamine acetate in healthy volunteers: a double-blind, randomized, placebo-controlled clinical trial

BACKGROUND

2-Hydroxybenzylamine (2-HOBA) is a selective dicarbonyl electrophile scavenger being developed as a nutritional supplement to help protect against the development of conditions associated with dicarbonyl electrophile formation, such as the cognitive decline observed with Mild Cognitive Impairment or Alzheimer's disease.

METHODS

This study evaluated the safety, tolerability, and pharmacokinetics of repeated oral doses of 2-HOBA acetate (500 or 750 mg) administered to healthy volunteers every eight hours for two weeks. The effects of 2-HOBA on cyclooxygenase function and cerebrospinal fluid penetrance of 2-HOBA were also investigated.

RESULTS

Repeated oral administration of 2-HOBA was found to be safe and well-tolerated up to 750 mg TID for 15 days. 2-HOBA was absorbed within 2 h of administration, had a half-life of 2.10-3.27 h, and an accumulation ratio of 1.38-1.52. 2-HOBA did not interfere with cyclooxygenase function and was found to be present in cerebrospinal fluid 90 min after dosing.

CONCLUSIONS

Repeated oral administration of 2-HOBA was found to be safe and well-tolerated. These results support continued development of 2-HOBA as a nutritional supplement.

TRIAL REGISTRATION

Studies are registered at ClinicalTrials.gov (NCT03555682 Registered 13 June 2018, NCT03554096 Registered 12 June 18).

Isolevuglandins as mediators of disease and the development of dicarbonyl scavengers as pharmaceutical interventions

Products of lipid peroxidation include a number of reactive lipid aldehydes such as malondialdehyde, 4-hydroxy-nonenal, 4-oxo-nonenal, and isolevuglandins (IsoLGs). Although these all contribute to disease processes, the most reactive are the IsoLGs, which rapidly adduct to lysine and other cellular primary amines, leading to changes in protein function, cross-linking and immunogenicity. Their rapid reactivity means that only IsoLG adducts, and not the unreacted aldehyde, can be readily measured. This high reactivity also makes it challenging for standard cellular defense mechanisms such as aldehyde reductases and oxidases to dispose of them before they react with proteins and other cellular amines. This led us to seek small molecule primary amines that might trap and inactivate IsoLGs before they could modify cellular proteins or other endogenous cellular amines such as phosphatidylethanolamines to cause disease. Our studies identified 2-aminomethylphenols including 2-hydroxybenzylamine as IsoLG scavengers. Subsequent studies showed that they also trap other lipid dicarbonyls that react with primary amines such as 4-oxo-nonenal and malondialdehyde, but not hydroxyalkenals like 4-hydroxy-nonenal that preferentially react with soft nucleophiles. This review describes the use of these 2-aminomethylphenols as dicarbonyl scavengers to assess the contribution of IsoLGs and other amine-reactive lipid dicarbonyls to disease and as therapeutic agents.