7,8-Dihydroxy-4-methylcoumarin Provides Neuroprotection by Increasing Hippocalcin Expression

Molecular Docking and Dynamics Simulation Studies Predict Potential Anti-ADAR2 Inhibitors: Implications for the Treatment of Cancer, Neurological, Immunological and Infectious Diseases

Altered RNA editing has been linked to several neurodevelopmental disorders, including autism spectrum disorder (ASD) and intellectual disability, in addition to depression, schizophrenia, some cancers, viral infections and autoimmune disorders. The human ADAR2 is a potential therapeutic target for managing these various disorders due to its crucial role in adenosine to inosine editing. This study applied consensus scoring to rank potential ADAR2 inhibitors after performing molecular docking with AutoDock Vina and Glide (Maestro), using a library of 35,161 compounds obtained from traditional Chinese medicine. A total of 47 compounds were predicted to be good binders of the human ADAR2 and had insignificant toxicity concerns. Molecular dynamics (MD) simulations, including the molecular mechanics Poisson–Boltzmann surface area (MM/PBSA) procedure, also emphasized the binding of the shortlisted compounds. The potential compounds had plausible binding free energies ranging from −81.304 to −1068.26 kJ/mol from the MM/PBSA calculations. ZINC000085511995, a naphthoquinone had more negative binding free energy (−1068.26 kJ/mol) than inositol hexakisphosphate (IHP) [−873.873 kJ/mol], an agonist and a strong binder of ADAR2. The potential displacement of IHP by ZINC000085511995 in the IHP binding site of ADAR2 could be explored for possible deactivation of ADAR2. Bayesian-based biological activity prediction corroborates the neuropharmacological, antineoplastic and antiviral activity of the potential lead compounds. All the potential lead compounds, except ZINC000014612330 and ZINC000013462928, were predicted to be inhibitors of various deaminases. The potential lead compounds also had probability of activity (Pa) > 0.442 and probability of inactivity (Pi) < 0.116 values for treating acute neurologic disorders, except for ZINC000085996580 and ZINC000013462928. Pursuing these compounds for their anti-ADAR2 activities holds a promising future, especially against neurological disorders, some cancers and viral infections caused by RNA viruses. Molecular interaction, hydrogen bond and per-residue decomposition analyses predicted Arg400, Arg401, Lys519, Trp687, Glu689, and Lys690 as hot-spot residues in the ADAR2 IHP binding site. Most of the top compounds were observed to have naphthoquinone, indole, furanocoumarin or benzofuran moieties. Serotonin and tryptophan, which are beneficial in digestive regulation, improving sleep cycle and mood, are indole derivatives. These chemical series may have the potential to treat neurological disorders, prion diseases, some cancers, specific viral infections, metabolic disorders and eating disorders through the disruption of ADAR2 pathways. A total of nine potential lead compounds were shortlisted as plausible modulators of ADAR2.

7, 8-Dihydroxy-4-methyl coumarin alleviates cholestasis via activation of the Farnesoid X receptor in vitro and in vivo

Cholestasis is primarily caused by bile acid homeostasis dysregulation, resulting in retention, aggregation, and accumulation of the toxic cholate in the hepatocytes. Existing therapies for cholestasis are limited, demanding the urgent development of novel drugs. As a result, targeting FXR specifically promises a unique treatment strategy for cholestasis. The current study aims to evaluate the influence of 7, 8-dihydroxy-4-methyl coumarin (DMC) against alpha-naphthyl isothiocyanate (ANIT)-induced liver injury in mice. The "Computer-Aided Drug Design" (CADD) and molecular docking study anticipated that DMC would proficiently bind and activate the FXR. Accordingly, the hepatoprotective activity of DMC against ANIT-induced hepatotoxicity and cholestasis was investigated in ANIT-treated HepaRG cells and the ANIT-induced cholestatic mouse model. Outcomes indicated the protective effects of DMC against ANIT toxicity in HepaRG cells after 24 h of intervention and animals after seven days of treatment. DMC partially blocks ANIT-induced increases in serum markers of hepatocellular injury, liver and gall bladder enlargement, and hepatic necrosis. Western blotting revealed that DMC alleviates ANIT-induced hepatotoxicity and cholestasis via activating the FXR receptor and regulating CYP7A1, the enzyme responsible for bile acid synthesis. DMC exhibited protective activity against cholestasis through activating FXR, suggesting it might be a promising strategy for preventing and treating cholestatic liver disease.

Anti-inflammatory Activities of 7,8-Dihydroxy-4-Methylcoumarin Acetylation Products via NF-κB and MAPK Pathways in LPS-Stimulated RAW 264.7 Cells

Coumarins are phenolic compounds that are characterized by fused benzene and α-pyrone rings. Among coumarin-based compounds, 7,8-dihydroxy-4-methylcoumarin (DHMC) has anti-inflammatory activities, but whether the level of this activity varies according to the degree of acetylation remains unknown. Therefore, we acetylated DHMC to yield monoacetylated 8-acetoxy-4-methylcoumarin (8AMC) and 7,8-diacetoxy-4-methylcoumarin (DAMC). We then compared the anti-inflammatory activities of DHMC with its acetylated derivatives and discovered a novel anti-inflammatory agent. We evaluated whether DHMC, 8AMC, and DAMC could inhibit lipopolysaccharide (LPS)-induced stimulation in RAW 264.7 cells. We found that DHMC, 8AMC, and DAMC induced a dose-dependent downregulation of nitric oxide (NO), prostaglandin E2 (PGE2), pro-inflammatory cytokine, inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2) expression at the mRNA and protein levels. Western blotting showed that DHMC, 8AMC, and DAMC inhibited phosphorylated mitogen-activated protein kinase (MAK), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38, and nuclear factor-kappa B (NF-κB) expression in a concentration-dependent manner. Furthermore, 8AMC was the most effective inhibitor with powerful anti-inflammatory activity. These results indicate that acetylation can improve the anti-inflammatory activity of natural precursors. We also discovered the new anti-inflammatory compounds 8AMC and DAMC.

Behavioral, neuroplasticity and metabolic effects of 7,8-dihydroxy-4-methylcoumarin associated with physical activity in mice

The search for strategies to develop resilience against metabolic and neuropsychiatric disorders has motivated the clinical and experimental assessment of early life interventions such as lifestyle-based and use of unconventional pharmacological compounds. In this study, we assessed the effects of voluntary physical activity and 7,8-Dihydroxy-4-methylcoumarin (DHMC), independently or in combination, over mice physiological and behavioral parameters, adult hippocampal and hypothalamic neurogenesis, and neurotrophic factors expression in the hypothalamus. C57Bl/6J mice were submitted to a 29-day treatment with DHMC and allowed free access to a running wheel. We found that DHMC treatment alone reduced fasting blood glucose levels. Moreover, physical activity showed an anxiolytic effect in the elevated plus maze task and DHMC produced additional anxiolytic behavior, evidenced by reduced activity during the light cycle in the physical activity group. Although we did not find any differences in hypothalamic or hippocampal adult neurogenesis, DHMC increased gene expression levels of VEGF, which was correlated to the reduced fasting glucose levels. In conclusion, our data emphasize the potential of physical activity in reducing development of neuropsychiatric conditions, such as anxiety, and highlights DHMC as an attractive compound to be investigated in future studies addressing neuropsychiatric disorders associated with metabolic conditions.

7, 8-Dihydroxy-4-methylcoumarin reverses depression model-induced depression-like behaviors and alteration of dendritic spines in the mood circuits

Major depressive disorder (MDD) is a common mental disorder characterized by a persistent feeling of sadness, slow thought, impaired focus and loss of interest but the underlying mechanisms are largely unknown. Dendritic spines play an important role in the formation and maintenance of emotional circuits in the brain. Abnormalities in this process can lead to psychiatric diseases. 7,8-Dihydroxy-4-methylcoumarin (Dhmc), a precursor in the synthesis of derivatives of 4-methyl coumarin, plays an important role in protecting the nervous system from developing diseases and its most distinctive feature is safety. The aim of this study was to investigate whether Dhmc alleviates chronic unpredictable mild stress (CUMS)-induced depression-like behaviors and reverses CUMS-induced alterations in dendritic spines of principal neurons in brain areas of the emotional circuits including the hippocampus, medial prefrontal cortex (mPFC), nucleus accumbens (NAc) and basolateral amygdala (BLA) in male rats. Our results showed that CUMS-induced depression-like behaviors were accompanied by a decrease in spine density in pyramidal neurons of both the hippocampal CA3 area and the mPFC, and an increase in spine density in both the neurons of BLA and the medium spiny neurons (MSNs) of the NAc, as well as a decrease in the levels of the AMPA receptor subunit GluA1 and Kalirin-7 in the hippocampus compared with the control group. Intraperitoneal injection (i.p.) of Dhmc to the CUMS-exposed rats ameliorated CUMS-induced depression-like behaviors and reversed CUMS-mediated alterations in spine density and the levels of both GluA1 and Kalirin-7. Our results show an important role of Dhmc in reversing CUMS-induced depression-like behaviors and CUMS-mediated alterations in spine density.

Neurocalcin-delta: a potential memory-related factor in hippocampus of obese rats induced by high-fat diet

Introduction

Aberrant protein expression within the hippocampus has recently been implicated in the pathogenesis of obesity-induced memory impairment.

Objectives

The objective of the current study was to search for specific memory-related factors in the hippocampus in obese rats.

Methods

Sprague-Dawley (SD) rats were fed either a high-fat (HF) diet or normal-fat (NF) diet for 10 weeks to obtain the control (CON), diet-induced obese rats (DIO) and diet-resistant (DR) rats. D-galactose was injected subcutaneously for 10 weeks to establish model (MOD) rats with learning and memory impairment. After the hippocampus of the rats sampling, the proteome analysis was conducted using two-dimensional get electrophoresis (2-DE) combined with peptide mass fingerprinting (PMF).

Results

We found 15 differential proteins that expressed in the hippocampus in rats induced by HF diet from the 2-DE map. In addition, Neurocalcin-delta (NCALD) was nearly down-regulated in the DR rats compared with CON rats and MOD rats, which was further confirmed by Western blot, real-time PCR and ELISA results.

Conclusion

Our data demonstrates that the differential memory-related proteins were a reflection of the HF diet, but not potential factors in obesity proneness or obesity resistance. Furthermore, NCALD is proved to be a potential hippocampus-memory related factor related to obesity.

Neuroprotective and Antioxidant Activities of 4-Methylcoumarins: Development of Structure-Activity Relationships

Coumarins are a major class of polyphenols that are abundantly present in many dietary plants and possess different biological activities. Neuroprotective effect of 28 variously substituted 4-methylcoumarins was evaluated in a cell model of oxidative stress-induced neurodegeneration, which measures viability in PC12 cells challenged with hydrogen peroxide by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The inhibitory activity of these compounds against intracellular reactive oxygen species (ROS) formation was also determined by 2',7'-dichlorofluorescein diacetate method in the same cells. Chemical redox-based assays including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) tests were employed to explore structure-antioxidant activity relationships in a cell-free environment. The results demonstrated that 4-methylcoumarins containing ortho-dihydroxy or ortho-diacetoxy substituents on the benzenoid ring possess considerable neuroprotective effects. ortho-Dihydroxy compounds inhibited cytotoxicity (44.7-62.9%) and ROS formation (41.6-71.1%) at 50 µM and showed considerable antioxidant effects. We conclude that 4-methylcoumarins are promising neuroprotective and antioxidant scaffolds potentially usefull for management of neurodegenerative diseases.

Implication of coumarins towards central nervous system disorders

Coumarins are widely distributed, plant-derived, 2H-1-benzopyran-2-one derivatives which have attracted intense interest in recent years as a result of their diverse and potent pharmacological properties. Particularly, their effects on the central nervous system (CNS) have been established. The present review discusses the most important pharmacological effects of natural and synthetic coumarins on the CNS, including their interactions with benzodiazepine receptors, their dopaminergic and serotonergic affinity, and their ability to inhibit cholinesterases and monoamine oxidases. The structure-activity relationships pertaining to these effects are also discussed. This review posits that natural or synthetic coumarins have the potential for development in the therapy of psychiatric and neurodegenerative disorders, including Alzheimer's and Parkinson's diseases, schizophrenia, anxiety, epilepsy, and depression.