Fraxetin attenuates disrupted behavioral and central neurochemical activity in a model of chronic unpredictable stress

Fraxetin attenuates DNA damage and inflammation in cisplatin-induced nephrotoxicity via FoxO1 activation

BACKGROUND

Cisplatin-induced acute kidney injury (CKI) represents a severe renal dysfunction characterized by DNA damage and tubular injury. Fraxetin, derived from the Chinese herb Qinpi (Fraxinus bungeana A.DOC), is recognized for its neuroprotective effects and has been used for the prevention of various diseases.

METHODS

This study investigated the renoprotective effects and molecular mechanisms of fraxetin in CKI. A mouse CKI model and a cisplatin-induced tubule epithelial cell (TEC) injury model were established to evaluate fraxetin's effects by measuring diverse parameters associated with kidney injury, focusing on DNA damage and inflammation. Additionally, network pharmacology and cellular sequencing analysis were employed to identify altered pathways or targets after fraxetin treatment. Subsequent experiments involved siRNA and pharmacological regulation to identify fraxetin targets, alongside molecular docking to unravel binding mechanisms.

RESULTS

Fraxetin pretreatment significantly ameliorated CKI, with a 45% reduction in in tubular damage compared to the cisplatin-only group. Additionally, fraxetin notably enhanced DNA repair. Fraxetin pretreatment reduced cisplatin-induced DNA damage in HK-2 cells by 42.8% in comet assays. Fraxetin also mitigated inflammation, with pro-inflammatory cytokine levels decreasing by approximately 20-30% in both mouse and cell models. Notable changes were observed in the FoxO pathway. Specifically, manipulating Forkhead box O1 (FoxO1), a transcription factor involved in stress responses and longevity, influenced fraxetin's protective effect. Molecular docking revealed that fraxetin binds to the Forkhead (FH) domain of FoxO1, promoting its nuclear localization.

CONCLUSIONS

Fraxetin protects against CKI by activating FoxO1, providing a foundation for novel therapeutic strategies and underscoring fraxetin's potential in treating kidney injury.

Engineering yeast to produce fraxetin from ferulic acid and lignin

Lignin, the most abundant renewable source of aromatic compounds on earth, remains underexploited in traditional biorefining. Fraxetin, a naturally occurring flavonoid, has garnered considerable attention in the scientific community due to its diverse and potent biological activities such as antimicrobial, anticancer, antioxidant, anti-inflammatory, and neurological protective actions. To enhance the green and value-added utilization of lignin, Saccharomyces cerevisiae was engineered as a cell factory to transform lignin derivatives to produce fraxetin. The expression of scopoletin 8-hydroxylase (S8H) and coumarin synthase (COSY) enabled S. cerevisiae to produce fraxetin from ferulic acid, one of the three principal monomers. The optimized fermentation strategies produced 19.1 mg/L fraxetin from ferulic acid by engineered S. cerevisiae. Additionally, the engineered cell factory achieved a fraxetin titer of 7.7 mg/L in lignin hydrolysate. This study successfully demonstrates the biotransformation of lignin monomers and lignin hydrolysate into fraxetin using a S. cerevisiae cell factory, thereby providing a viable strategy for the valorization of lignin. KEY POINTS: • AtS8H showed substance specificity in the hydroxylation of scopoletin. • AtCOSY and AtS8H were key enzymes for converting ferulic acid into fraxetin. • Yeast was engineered to produce fraxetin from lignin hydrolysate.

Exploring the active components and potential mechanisms of Alpiniae oxyphyllae Fructus in treating diabetes mellitus with depression by UPLC-Q-Exactive Orbitrap/MS, network pharmacology and molecular docking

The growing incidence of diabetes mellitus (DM) and depression is a global public health issue. Alpiniae oxyphyllae Fructus (AOF) is a kind of medicinal and edible plant which be found with anti-diabetic property, and could improve depression-like symptoms. This study aimed to screen active targets and potential mechanisms of AOF in treating DM with depression. Injection of streptozotocin (STZ) and exposure to chronic unpredictable mild stress (CUMS) for 4 weeks were used to conduct the DM with depression mice model. Behavioral tests, indexes of glucose metabolism, monoamine neurotransmitters, inflammatory cytokine and oxidative stress were measured. Histopathological change of hippocampus tissue was observing by HE and Nissl staining. UPLC-Q-Exactive Orbitrap/MS, network pharmacology and molecular docking were used to explore the chemical components and mechanisms of AOF on the DM with depression. AOF showed a reversed effect on body weight in DM with depression mice. Glucose metabolism and insulin resistance could be improved by treatment of AOF. In addition, AOF could alleviate depression-like behaviors based on the results of behavior tests and monoamine neurotransmitters. AOF also attenuated STZ-CUMS induced neuron injury in hippocampus. Next, a total of 61 chemical components were identified in the UPLC-Q-Exactive Orbitrap/MS analysis of the extract of AOF. Network pharmacology analysis suggested that 12 active components and 227 targets were screened from AOF, and 1802 target genes were screened from DM with depression, finally 126 intersection target genes were obtained. Drug-disease targets network was constructed and implied that the top five components with a higher degree value includes quercetin, nootkatone, baicalein, (-)-epicatechin and nootkatol. Protein-protein interaction (PPI) network showed that MAPK1, FOS, AKT1, IL6 and TP53 may be the core intersection targets. The mechanism of the effect of AOF on DM with depression was analyzed through gene ontology (GO), and kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis, mainly involved in AGE/RAGE, PI3K/AKT, and MAPK signaling pathways. The results of molecular docking indicated that quercetin, nootkatone, baicalein, (-)-epicatechin and nootkatol all had good binding to the core intersection targets. Overall, our experimental researches have demonstrated that AOF could exert the dual effects of anti-diabetic and anti-depression on DM with depression mice, through multi-targets and multi-pathways.

Health benefits of fraxetin: From chemistry to medicine

Fraxetin is a bioactive molecule present in various natural plants, especially Cortex Fraxini. Evidenced outcomes in phytochemical and biological analyses for this agent are now available in the literature, but an insightful review is yet unknown. The goal of the current research is to offer a panoramic illustration of natural observation, biosynthesis, synthesis, pharmacology, and pharmacokinetics for fraxetin. Esculetin and ferulic acid acted as precursors in the enzymatic biosynthetic route, whereas fraxetin could be easily synthesized from simple phenols. A great deal of interest was obtained in using this molecule for pharmacological targets. Herein, its pharmacological value included anticancer, antioxidative, anti-inflammatory, antidiabetic, antiobesity, and antimicrobial activities, as well as the protection of the liver, neurons, heart, bone, lung, kidney, and others. Anticancer activity may involve the inhibition of proliferation, invasion, and migration, together with apoptotic induction. Health benefits from this molecule were deduced from its ability to suppress cytokines and protect the immune syndrome. Various signaling pathways, such as Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3), phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt), nuclear factor kappa B (NF-κB)/NLRP3, Akt/AMPK, have been proposed for in vitro and in vivo mechanisms of action. Fraxetin is highly distributed to rat plasma and several organs. However, more pharmacokinetic studies to improve its bioavailability are needed since its solubility in water is still limited.

3-Acetyl coumarin alleviate neuroinflammatory responses and oxidative stress in aluminum chloride-induced Alzheimer's disease rat model

Alzheimer's disease (AD) is a neurodegenerative disorder that impairs mental ability and interrupts cognitive function. Heavy metal exposure like aluminum chloride is associated with neurotoxicity linked to neuro-inflammation, oxidative stress, accumulation of amyloid plaques, phosphorylation of tau proteins associated with AD like symptoms. The objective of the present investigation was to assess the effect 3-acetyl coumarin (3AC) in a rat model of AD. Preliminary screening was performed with SWISS ADME to check for the bioavailability of 3-AC and likeness score which proved favorable. 3-AC docked against Caspase 3, NF-κβ and tau protein kinase I exhibited good binding energies. Male rats were divided into six groups (n = 5). AlCl3 (100 mg/kg BW) was administered for 28 days before starting treatment to induce AD. Normal control rats received vehicle. Treatment groups received 10, 20 and 30 mg/kg 3-AC for 28 days. Rivastigmine (2 mg/kg) was the standard. Behavioral tests (EPM, MWM) were performed at 7-day intervals throughout study period. Rats showed improved spatial memory and learning in treatment groups during behavioral tests. Rats were euthanized on day 28. Inflammatory markers (IL-1β, IL-16 and TNFα) exhibited significant improvement (p < 0.001) in treated rats. Oxidative stress enzymes (SOD, CAT, GSH, MDA) were restored. Caspase3 and NF-κβ quantified through qRT-PCR also decreased significantly (p < 0.001) when compared to disease control group. Levels of acetyl cholinesterase, dopamine and noradrenaline were also restored in treated rats significantly (p < 0.001). 3-AC treatment restored neuroprotection probably because of anti-inflammatory, anti-oxidant and anti-cholinesterase potential; hence, this can be considered a promising therapeutic potential alternative.

Chronic Stress-Induced Elevation of Melanin-Concentrating Hormone in the Locus Coeruleus Inhibits Norepinephrine Production and Associated With Depression-Like Behaviors in Rats

BACKGROUND

Melanin-concentrating hormone (MCH) is a hypothalamic neuropeptide that projects throughout the central nervous system, including the noradrenergic locus coeruleus (LC). Our previous study suggested that MCH/MCH receptor 1 (MCHR1) in the LC may be involved in the regulation of depression. The present study investigated whether the role of MCH/MCHR1 in the LC in depression-like behaviors is associated with the regulation of norepinephrine.

METHOD

Chronic unpredictable stress (CUS) and an acute intra-LC microinjection of MCH induced depression-like behaviors in rats. The MCHR1 antagonist SNAP-94847 was also microinjected in the LC in rats that were suffering CUS or treated with MCH. The sucrose preference, forced swim, and locomotor tests were used for behavioral evaluation. Immunofluorescence staining, enzyme-linked immunosorbent assay, western blot, and high-performance liquid chromatography with electrochemical detection were used to explore the mechanism of MCH/MCHR1 in the regulation of depression-like behaviors.

RESULTS

CUS induced an abnormal elevation of MCH levels and downregulated MCHR1 in the LC, which was highly correlated with the formation of depression-like behaviors. SNAP-94847 exerted antidepressant effects in CUS-exposed rats by normalizing tyrosine hydroxylase, dopamine β hydroxylase, and norepinephrine in the LC. An acute microinjection of MCH induced depression-like behaviors through its action on MCHR1. MCHR1 antagonism in the LC significantly reversed the MCH-induced downregulation of norepinephrine production by normalizing MCHR1-medicated cAMP-PKA signaling.

CONCLUSIONS

Our study confirmed that the MCH/MCHR1 system in the LC may be involved in depression-like behaviors by downregulating norepinephrine production. These results improve our understanding of the pathogenesis of depression that is related to the MCH/MCHR1 system in the LC.

Diosgenin normalization of disrupted behavioral and central neurochemical activity after single prolonged stress

Introduction: Post-traumatic stress disorder (PTSD) is a chronic mental illness triggered by traumatic experiences such as wars, natural disasters, or catastrophes, and it is characterized by anxiety, depression and cognitive impairment. Diosgenin is a steroidal sapogenin with known neuroprotective and antioxidant properties. This study aimed to assess the pharmacological potential of diosgenin in a single prolonged stress (SPS) model of PTSD, plus other behavioral models along with any consequent alterations in brain neurochemistry in male mice. Methodology: SPS was induced by restraining animals for 2 h, followed by 20 min of forced swim, recuperation for 15 min, and finally, exposure to ether to induce anesthesia. The SPS-exposed animals were treated with diosgenin (20, 40, and 60 mg/kg) and compared with the positive controls, fluoxetine or donepezil, then they were observed for any changes in anxiety/depression-like behaviors, and cognitive impairment. After behavioral screening, postmortem serotonin, noradrenaline, dopamine, vitamin C, adenosine and its metabolites inosine and hypoxanthine were quantified in the frontal cortex, hippocampus, and striatum by high-performance liquid chromatography. Additionally, animal serum was screened for changes in corticosterone levels. Results: The results showed that diosgenin reversed anxiety- and depression-like behaviors, and ameliorated cognitive impairment in a dose-dependent manner. Additionally, diosgenin restored monoamine and vitamin C levels dose-dependently and modulated adenosine and its metabolites in the brain regions. Diosgenin also reinstated otherwise increased serum corticosterone levels in SPS mice. Conclusion: The findings suggest that diosgenin may be a potential candidate for improving symptoms of PTSD.