Effect of Coffee against MPTP-Induced Motor Deficits and Neurodegeneration in Mice Via Regulating Gut Microbiota

Exploring the Association of dietary index for gut microbiota with Parkinson's disease and depression: Insights from NHANES

BACKGROUND

Depression and Parkinson's disease (PD) are important public health issues strongly associated with diet and gut microbiota. The aim of this study was to investigate the association of the dietary index for gut microbiota (DI-GM) with Parkinson's disease and depression.

METHODS

This cross-sectional study used data from the National Health and Nutrition Examination Survey (NHANES) database (2007-2020), with a total of 26,473 participants aged 18-80 years, weighted to represent 256 million US adults. Dietary recall data were used to calculate the DI-GM. Weighted logistic regression was used to analyze the relationship between the DI-GM and depression and PD, and to explore the potential mediating role of the DI-GM in depression and PD. Subgroup analyses and restricted cubic spline (RCS) analyses were also performed.

RESULTS

The weighted prevalence of PD combined with depression was approximately 22.99 %. We found a possible inverted U-shaped relationship between DI-GM and depression. Higher DI-GM scores were associated with a lower risk of PD (OR = 0.84, 95 % CI (0.75,0.94)). Mediation modelling indicated no significant role for DI-GM in the relationship between depression and PD. The RCS showed a non-linear association between DI-GM and PD.

CONCLUSIONS

A dose-dependent nonlinear association was identified between the DI-GM and PD. Preliminary evidence suggests a potential inverted U-shaped DI-GM-depression relationship requiring validation. This suggests that focusing on DI-GM may be helpful in studying PD and depression.

Parkinson's Disease and the Microbiota-Gut-Brain Axis: Metabolites, Mechanisms, and Innovative Therapeutic Strategies Targeting the Gut Microbiota

The human gut microbiota is diverse and abundant and plays important roles in regulating health by participating in metabolism and controlling physiological activities. The gut microbiota and its metabolites have been shown to affect the functioning of the gut and central nervous system through the microbiota-gut-brain axis. It is well established that microbiota play significant roles in the pathogenesis and progression of Parkinson's disease (PD). Disorders of the intestinal microbiota and altered metabolite levels are closely associated with PD. Here, the changes in intestinal microbiota and effects of metabolites in patients with PD are reviewed. Potential mechanisms underlying intestinal microbiota disorders in the pathogenesis of PD are briefly discussed. Additionally, we outline the current strategies for the treatment of PD that target the gut microbiota, emphasizing the development of promising novel strategies.

SVHRSP protects against rotenone-induced neurodegeneration in mice by inhibiting TLR4/NF-κB-mediated neuroinflammation via gut microbiota

Strong evidence indicates that remodeling gut microbiota may be an effective approach to combat Parkinson's disease (PD). Scorpion Venom Heat-Resistant Synthesized Peptide (SVHRSP), a synthesized peptide discovered from scorpion venom, displays potent neuroprotection in multiple PD models. However, the potential mechanisms remain unclear. In this study, we demonstrated that SVHRSP effectively attenuated gastrointestinal function impairments and reinstated the microbiota composition in rotenone-induced PD mouse model. Microbiota depletion and FMT verified that the restored gut microbiota was necessary for SVHRSP-mediated neuroprotection against dopaminergic neurodegeneration in rotenone PD mice. Furthermore, SVHRSP gut microbiota-dependently attenuated BBB impairment, microglial activation, and gene expression of pro-inflammatory factors in rotenone-treated mice. Mechanistically, SVHRSP decreased the concentrations of LPS and HMGB1 in both serum and brain tissue, thereby inhibiting the TLR4/NF-κB signaling pathway in the brain of rotenone-treated mice. Together, our findings provided fresh perspectives on the mechanisms underlying SVHRSP-induced neuroprotection in PD.

Coffee and Parkinson's disease

Parkinson's disease (PD) is a prevalent neurodegenerative disease marked by dopaminergic neuronal loss and misfolded alpha-synuclein (α-syn) accumulation, which results in both motor and cognitive symptoms. Its occurrence grows with age, with a larger prevalence among males. Despite substantial study, effective medicines to reduce or stop the progression of diseases remain elusive. Interest has grown in examining dietary components, such as caffeine present in coffee, for potential medicinal effects. Epidemiological studies imply a lower incidence of PD with coffee drinking, attributable to caffeine's neuroprotective abilities. Beyond caffeine, coffee constituent like chlorogenic acid and cafestol have anti-Parkinsonian benefits. Moreover, coffee use has been related with variations in gut microbiota composition, which may reduce intestinal inflammation and prevent protein misfolding in enteric nerves, perhaps through the microbiota-gut-brain axis. This review gives a summary of the neuroprotective effects of coffee, investigating both its motor and non-motor advantages in individuals with PD as well as in experimental models of PD. We reviewed some bioactive constituents of coffee, their respective interactions with misfolded α-syn accumulation, and its emerging mechanisms associated to the gut microbiome.

Gastrodia elata polysaccharide alleviates Parkinson's disease via inhibiting apoptotic and inflammatory signaling pathways and modulating the gut microbiota

Parkinson's disease (PD) is a common, chronic, and progressive degenerative disease of the central nervous system for which there is no effective treatment. Gastrodia elata is a well-known food and medicine homologous resource with neuroprotective potential. Gastrodia elata polysaccharide (GEP), which is a highly active and safe component in Gastrodia elata, is an important ingredient in the development of functional products. In this study, GEP was administered to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mice over 3 weeks to investigate its neuroprotective effects. The results showed that GEP significantly alleviated the motor dysfunction of PD mice, inhibited the accumulation of α-synuclein, and reduced the loss of dopaminergic neurons in the brain. Moreover, GEP increased the Bcl-2/Bax ratio and decreased the cleaved-caspase-3 level, suggesting that GEP may ameliorate PD by preventing MPTP-induced mitochondrial apoptosis. GEP also significantly inhibited the increase of GFAP and decreased the levels of TNF-α, IL-1β, and IL-6 in the brain of PD mice, which may be the result of the inhibition of neuroinflammation by the inactivation of the TLR4/NF-κB pathway. Furthermore, the neuroprotective effects of GEP involve the gut-brain axis, as it has been shown that GEP regulated the dysbiosis of PD-related gut microbiota such as Akkermansia, Lactobacillus, Bacteroides, Prevotella, and Faecalibacterium, increased the content of microbial metabolites SCFAs in the colon and increased the level of occludin that repairs the intestinal barrier of PD mice. In conclusion, this study is expected to provide a theoretical basis for the development and application of functional products with GEP from the perspective of neuroprotective effects.

Neuroprotective effect of a medium-chain triglyceride ketogenic diet on MPTP-induced Parkinson's disease mice: a combination of transcriptomics and metabolomics in the substantia nigra and fecal microbiome

The ketogenic diet (KD) is a low carbohydrate and high-fat protein diet. It plays a protective role in neurodegenerative diseases by elevating the levels of ketone bodies in blood, regulating central and peripheral metabolism and mitochondrial functions, inhibiting neuroinflammation and oxidative stress, and altering the gut microbiota. However, studies on ketogenic therapy for Parkinson's disease (PD) are still in their infancy. Therefore, we examined the possible protective effect of KD in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model, examined the mouse gut microbiota and its metabolites, and performed transcriptomics and metabolomics on the substantia nigra of mice. Our results showed that a long-term medium-chain triglyceride KD (MCT-KD) significantly reduced MPTP-induced damage to dopaminergic (DA) neurons, exerted antioxidant stress through the PI3K/Akt/Nrf2 pathway, and reversed oxidative stress in DA neurons. The MCT-KD also reduced mitochondrial loss, promoted ATP production, and inhibited the activation of microglia to protect DA neurons in MPTP-induced PD mice. MCT-KD altered the gut microbiota and consequently changed the metabolism of substantia nigra neurons through gut microbiota metabolites. Compared to the MPTP group, MCT-KD increased the abundance of gut microbiota, including Blautia and Romboutsia. MCT-KD also affects purine metabolism in the substantia nigra pars compacta (SNpc) by altering fecal metabolites. This study shows that MCT-KD has multiple protective effects against PD.

Coffee prevents IQ-induced liver damage by regulating oxidative stress, inflammation, endoplasmic reticulum stress, autophagy, apoptosis, and the MAPK/NF-κB signaling pathway in zebrafish

2-Amino-3-methylimidazole[4,5-f]quinoline (IQ), one of heterocyclic amines (HCAs) produced in proteinaceous foods upon heating, is recognized as a carcinogen. Previous studies have confirmed that IQ intake can cause liver damage in zebrafish. In the current study, we revealed the protective effects of coffee against IQ-induced liver damage. We exposed one-month-old wild-type zebrafish to IQ (80 ng/mL) and coffee at 50 mg/L, 100 mg/L, and 300 mg/L for 35 days. Markers of oxidative stress, inflammation, endoplasmic reticulum stress (ERS), autophagy, and apoptosis in the liver were assessed to explore the potential mechanisms of the protective effects. The results showed that coffee effectively improved IQ-induced liver damage by reducing ALT, AST, TC, TG, and LDL-C levels, increasing HDL-C level, and restoring hepatic morphology. Moreover, coffee showed an antioxidative effect by increasing GSH, GSH-Px, GST, CAT, and SOD levels and attenuating ROS and MDA contents. Additionally, coffee reduced the NO, iNOS, TNF-α, IL-6, IL-1β, and IL-12 expression levels, presenting an anti-inflammatory effect. Furthermore, coffee protected against ERS, autophagy dysfunction, and apoptosis by decreasing the GRP78, CHOP, and p62 while increasing the Atg5-Atg12, Beclin1, LC3-II, and Bcl-2 expression levels. TUNEL results showed that coffee rescued IQ-induced hepatocyte apoptosis. In addition, coffee interrupted the MAPK/NF-κB signaling pathway by suppressing the phosphorylation expressions of JNK, ERK, p38, p65, and IκB. These findings indicated that coffee prevents IQ-induced liver damage with antioxidative, anti-inflammatory, anti-ERS, anti-apoptotic, and pro-autophagic effects, thus to serve as a functional beverage with potential health benefits.

Effect of gastrodin against cognitive impairment and neurodegeneration in APP/PS1 mice via regulating gut microbiota-gut-brain axis

Gastrodin (Gas) has exhibited protective activity in neurological disorders. Here, we investigated the neuroprotective effect and potential mechanisms of Gas against cognitive impairment via regulating gut microbiota. APPswe/PSEN1dE9 transgenic (APP/PS1) mice were treated intragastrically with Gas for 4 weeks, and then cognitive deficits, deposits of amyloid-β (Aβ) and phosphorylation of tau were analyzed. The expression levels of insulin-like growth factor-1 (IGF-1) pathway-related proteins, such as cAMP response element-binding protein (CREB), were detected. Meanwhile, gut microbiota composition was evaluated. Our results showed that Gas treatment significantly improved cognitive deficits and Aβ deposition in APP/PS1 mice. Moreover, Gas treatment increased the level of Bcl-2 and decreased level of Bax and ultimately inhibited neuronal apoptosis. Gas treatment markedly increased the expression levels of IGF-1 and CREB in APP/PS1 mice. Moreover, Gas treatment improved abnormal composition and structure of gut microbiota in APP/PS1 mice. These findings revealed that Gas actively participated in regulating the IGF-1 pathway to inhibit neuronal apoptosis via the gut-brain axis and that it can be considered a new therapeutic strategy against Alzheimer's disease.

Carnosol Reduced Pathogenic Protein Aggregation and Cognitive Impairment in Neurodegenerative Diseases Models via Improving Proteostasis and Ameliorating Mitochondrial Disorders

Neurodegenerative diseases (NDs) such as Alzheimer's disease, Parkinson's disease, and Huntington's disease are incurable diseases with progressive loss of neural function and require urgent development of effective treatments. Carnosol (CL) reportedly has a pharmacological effect in the prevention of dementia. Nevertheless, the mechanisms of CL's neuroprotection are not entirely clear. The present study aimed to investigate the effects and mechanisms of CL-mediated neuroprotection through Caenorhabditis elegans models. First, CL restored ND protein homeostasis via inhibiting the IIS pathway, regulating MAPK signaling, and simultaneously activating molecular chaperone, thus inhibiting amyloid peptide (Aβ), polyglutamine (polyQ), and α-synuclein (α-syn) deposition and reducing protein disruption-mediated behavioral and cognitive impairments as well as neuronal damages. Furthermore, CL could repair mitochondrial structural damage via improving the mitochondrial membrane protein function and mitochondrial structural homeostasis and improve mitochondrial functional defects via increasing adenosine triphosphate contents, mitochondrial membrane potential, and reactive oxygen species levels, suggesting that CL could improve the ubiquitous mitochondrial defects in NDs. More importantly, we found that CL activated mitochondrial kinetic homeostasis related genes to improve the mitochondrial homeostasis and dysfunction in NDs. Meanwhile, CL up-regulated unc-17, cho-1, and cha-1 genes to alleviate Aβ-mediated cholinergic neurological disorders and activated Notch signaling and the Wnt pathway to diminish polyQ- and α-syn-induced ASH neurons as well as dopaminergic neuron damages. Overall, our study clarified the beneficial anti-ND neuroprotective effects of CL in different aspects and provided new insights into developing CL into products with preventive and therapeutic effects on NDs.

Gut Microbiota: A Novel Therapeutic Target for Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease characterized by motor dysfunction. Growing evidence has demonstrated that gut dysbiosis is involved in the occurrence, development and progression of PD. Numerous clinical trials have identified the characteristics of the changed gut microbiota profiles, and preclinical studies in PD animal models have indicated that gut dysbiosis can influence the progression and onset of PD via increasing intestinal permeability, aggravating neuroinflammation, aggregating abnormal levels of α-synuclein fibrils, increasing oxidative stress, and decreasing neurotransmitter production. The gut microbiota can be considered promising diagnostic and therapeutic targets for PD, which can be regulated by probiotics, psychobiotics, prebiotics, synbiotics, postbiotics, fecal microbiota transplantation, diet modifications, and Chinese medicine. This review summarizes the recent studies in PD-associated gut microbiota profiles and functions, the potential roles, and mechanisms of gut microbiota in PD, and gut microbiota-targeted interventions for PD. Deciphering the underlying roles and mechanisms of the PD-associated gut microbiota will help interpret the pathogenesis of PD from new perspectives and elucidate novel therapeutic strategies for PD.

Environmental Impact on the Epigenetic Mechanisms Underlying Parkinson’s Disease Pathogenesis: A Narrative Review

Parkinson’s disease (PD) is the second most common neurodegenerative disorder with an unclear etiology and no disease-modifying treatment to date. PD is considered a multifactorial disease, since both genetic and environmental factors contribute to its pathogenesis, although the molecular mechanisms linking these two key disease modifiers remain obscure. In this context, epigenetic mechanisms that alter gene expression without affecting the DNA sequence through DNA methylation, histone post-transcriptional modifications, and non-coding RNAs may represent the key mediators of the genetic–environmental interactions underlying PD pathogenesis. Environmental exposures may cause chemical alterations in several cellular functions, including gene expression. Emerging evidence has highlighted that smoking, coffee consumption, pesticide exposure, and heavy metals (manganese, arsenic, lead, etc.) may potentially affect the risk of PD development at least partially via epigenetic modifications. Herein, we discuss recent accumulating pre-clinical and clinical evidence of the impact of lifestyle and environmental factors on the epigenetic mechanisms underlying PD development, aiming to shed more light on the pathogenesis and stimulate future research.