Alzheimer's Disease and Green Tea: Epigallocatechin-3-Gallate as a Modulator of Inflammation and Oxidative Stress

Safeguarding the brain from oxidative damage

Oxidative stress imposes a substantial cellular burden on the brain and contributes to diverse neurodegenerative diseases. Various antioxidant signaling pathways have been implicated in oxidative stress and have a protective effect on brain cells by increasing the release of numerous enzymes and through anti-inflammatory responses to oxidative damage caused by abnormal levels of reactive oxygen species (ROS). Although many molecules evaluated as antioxidants have shown therapeutic potentials in preclinical studies, the results of clinical trials have been less than satisfactory. This review focuses on several signaling pathways involved in oxidative stress that are associated with antioxidants. These pathways have a protective effect against stressors by increasing the release of various enzymes and also exert anti-inflammatory responses against oxidative damage. There is no doubt that oxidative stress is a crucial therapeutic target in the treatment of neurological diseases. Therefore, it is essential to understand the discovery of multiple routes that can efficiently repair the damage caused by ROS and prevent neurodegenerative disorders. This paper aims to provide a concise and objective review of the oxidative and antioxidant pathways and their potential therapeutic applications in treating oxidative injury in the brain.

Associations of Coffee and Tea Consumption on Neural Network Connectivity: Unveiling the Role of Genetic Factors in Alzheimer's Disease Risk

BACKGROUND

Coffee and tea are widely consumed beverages, but their long-term effects on cognitive function and aging remain largely unexplored. Lifestyle interventions, particularly dietary habits, offer promising strategies for enhancing cognitive performance and preventing cognitive decline.

METHODS

This study utilized data from the UK Biobank cohort (n = 12,025) to examine the associations between filtered coffee, green tea, and standard tea consumption and neural network functional connectivity across seven resting-state networks. We focused on networks spanning prefrontal and occipital areas that are linked to complex cognitive and behavioral functions. Linear mixed models were used to assess the main effects of coffee and tea consumption, as well as their interactions with Apolipoprotein E (APOE) genetic risk-the strongest genetic risk factor for Alzheimer's disease (AD).

RESULTS

Higher filtered coffee consumption was associated with increased functional connectivity in several networks, including Motor Execution, Sensorimotor, Fronto-Cingular, and a Prefrontal + 'What' Pathway Network. Similarly, greater green tea intake was associated with enhanced connectivity in the Extrastriate Visual and Primary Visual Networks. In contrast, higher standard tea consumption was linked to reduced connectivity in networks such as Memory Consolidation, Motor Execution, Fronto-Cingular, and the "What" Pathway + Prefrontal Network. The APOE4 genotype and family history of AD influenced the relationship between coffee intake and connectivity in the Memory Consolidation Network. Additionally, the APOE4 genotype modified the association between standard tea consumption and connectivity in the Sensorimotor Network.

CONCLUSIONS

The distinct patterns of association between coffee, green tea, and standard tea consumption and resting-state brain activity may provide insights into AD-related brain changes. The APOE4 genotype, in particular, appears to play a significant role in modulating these relationships. These findings enhance our knowledge of how commonly consumed beverages may influence cognitive function and potentially AD risk among older adults.

Role of Flavonoids in Mitigating the Pathological Complexities and Treatment Hurdles in Alzheimer's Disease

With the passage of time, people step toward old age and become more prone to several diseases associated with the age. One such is Alzheimer's disease (AD) which results into neuronal damage and dementia with the progression of age. The existing therapeutics has been hindered by various enkindles like less eminent between remote populations, affordability issues and toxicity profiles. Moreover, lack of suitable therapeutic option further worsens the quality of life in older population. Developing an efficient therapeutic intervention to cure AD is still a challenge for medical fraternity. Recently, alternative approaches attain the attention of researchers to focus on plant-based therapy in mitigating AD. In this context, flavonoids gained centrality as a feasible treatment in modifying various neurological deficits. This review mainly focuses on the pathological facets and economic burden of AD. Furthermore, we have explored the possible mechanism of flavonoids with the preclinical and clinical aspects for curing AD. Flavonoids being potential therapeutic, target the pathogenic factors of AD such as oxidative stress, inflammation, metal toxicity, Aβ accumulation, modulate neurotransmission and insulin signaling. In this review, we emphasized on potential neuroprotective effects of flavonoids in AD pathology, with focus on both experimental and clinical findings. While preclinical studies suggest promising therapeutic benefits, clinical data remains limited and inconclusive. Thus, further high-quality clinical trials are necessary to validate the efficacy of flavonoids in AD. The study aim is to promote the plant-based therapies and encourage people to add flavonoids to regular diet to avail the beneficial effects in preventive therapy for AD.

Potential Protective Effects of Pungent Flavor Components in Neurodegenerative Diseases

Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD) have become a major global health burden, but the detailed pathogeneses of neurodegenerative diseases are still unknown, and current treatments are mainly aimed at controlling symptoms; there are no curative treatments for neurodegenerative diseases or treatments for the progressive cognitive, behavioral, and functional impairments that they cause. Studies have shown that some plant extracts with pungent flavor components have a certain neuroprotective effect in neurodegenerative diseases, and their mechanisms mainly involve inhibiting neuronal apoptosis, promoting neuronal regeneration, reducing mitochondrial degeneration, and reducing the production of oxides such as reactive oxygen species in cells, which are of great significance for exploring the treatment of neurodegenerative diseases. In this review, we searched the PubMed database for relevant literature collected in the past 15 years. Finally, we summarized the protective effects of pungent flavor components such as capsaicin, piperine, curcumin, cannabinoids, allicin, and nicotine on the nervous system, focusing on the molecular mechanisms and signaling pathways that they activate. In addition, we also compiled and summarized the laboratory experiments, preclinical experiments, and effects of various pungent flavor components in neurodegenerative diseases. The goal is to further explore their potential as effective drugs for the treatment of neurodegenerative diseases and provide new ideas for further research on the specific protective mechanisms of these substances for the treatment of neurodegenerative diseases and the targets of drug action in the future.

Associations among healthy lifestyle characteristics, neuroinflammation, and cerebrospinal fluid core biomarkers of Alzheimer's disease in cognitively intact adults: The CABLE study

BACKGROUND

The occurrence of Alzheimer's disease (AD) can be partially prevented through healthy lifestyles, but the mechanisms associated with AD pathology are unclear.

OBJECTIVE

To explore associations among healthy lifestyle characteristics (HLCs), cerebrospinal fluid (CSF) soluble TREM2 (sTREM2), and AD biomarkers.

METHODS

From the Chinese Alzheimer's Biomarker and LifestylE (CABLE) study, 924 cognitively normal participants were enrolled in this cross-sectional analysis. We defined the following 11 HLCs: appropriate frequencies of coffee and tea consumption, sufficient frequencies of fish and fruit intake, non-social isolation, adequate sleep, regular physical activity, no depression, never smoking, non-hazardous drinking, and well-maintained blood pressure. We categorized participants according to the number of HLCs reported by participants into favorable, intermediate, and unfavorable lifestyle groups. Multiple linear regression was used to investigate the relationship among HLCs, CSF sTREM2, and AD biomarkers. Mediation effects were tested using a causal mediation analysis having 10,000 bootstrap iterations.

RESULTS

Included subjects were with a mean age of 61.8 ± 10.2 years, of which 41.8% were female. Sufficient fish intake (β = -0.164, p = 0.017) and well-maintained blood pressure (β = -0.232, p = 0.006) were significantly correlated with lower CSF sTREM2 levels. A larger number of HLCs were associated with lower CSF T-tau (p = 0.001), P-tau (p = 0.012), and sTREM2 (p = 0.040) levels. CSF sTREM2 partially mediated the association between the number of HLCs and CSF tau pathology (mediating proportion T-tau: 22.4%; P-tau: 25.0%).

CONCLUSIONS

HLCs might impact the pathological processes of AD by regulating neuroinflammation.

Bioinformatics Analysis and Experimental Validation of Epigallocatechin-3-gallate Against Iopromide-induced Injury in HEK-293 Cells via Anti-oxidative and Anti-inflammation Pathways

BACKGROUND/AIM

The administration of contrast agents can adversely affect kidney function. Nevertheless, the nephrotoxicity of iopromide in human renal cells, potential therapeutic agents, and the underlying molecular mechanisms have not been thoroughly investigated.

MATERIALS AND METHODS

The proliferation of HEK-293 kidney cells was assessed using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazoliumbromide (MTT) assay. Apoptotic cell death was examined using the TUNEL assay and caspase-3 activity measurements. The impacts and potential pathways of epigallocatechin-3-gallate (EGCG) on iopromide-induced renal damage were analyzed through whole transcriptome sequencing. The redox state was assessed by measuring reactive oxygen species (ROS) production and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity.

RESULTS

Iopromide-induced inhibition of cell proliferation and apoptosis in HEK-293 cells was counteracted by EGCG co-treatment. Pathway analysis revealed that molecules related to antioxidant and anti-inflammatory responses, such as ERK1/2, STAT1, and NF-[Formula: see text]B, were pivotal in the action of EGCG.

CONCLUSION

Iopromide-induced ROS production, decreased DPPH scavenging ability, DNA strand breaks, elevated caspase-3 activity, and reduced cell proliferation were all reversed by EGCG co-treatment in HEK-293 cells. The mechanisms likely involve the attenuation of oxidative stress, inflammatory responses, and apoptosis, with regulation through the ERK1/2, STAT1, and NF-[Formula: see text]B pathways. Further research is necessary to confirm the protective effects of EGCG on renal function, particularly against damage induced by contrast agents like iopromide.

Valorizing Tea Waste: Green Synthesis of Iron Nanoparticles for Efficient Dye Removal from Water

This study explores the valorization of tea leaf waste by extracting polyphenols through reflux extraction, subsequently using them to synthesize zero-valent iron nanoparticles (nZVI). The in situ generated nanoparticles, when combined with fixed amounts of hydrogen peroxide, facilitated the removal of various dyes (methylene blue, methyl orange, and orange G) via a hetero-catalytic Fenton process. The iron nanoparticles were thoroughly characterized by gas adsorption of N2 at 77 K, scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM), FT-IR spectroscopy, X-ray diffraction (XRD), and thermal analysis, including thermogravimetric analysis (TG) and temperature-programmed reduction (TPR). A statistical design of experiments and response surface methodology were employed to analyze the influence of polyphenol, Fe(III), and H2O2 concentrations on dye removal efficiency. The results demonstrated that optimizing the operational conditions could achieve 100% dye removal efficiency. This study highlights the potential of nZVI synthesized through eco-friendly methods as a promising solution for water decontamination involving diverse model dyes, thus contributing to sustainable waste management and environmental protection.

Development of Epigallocatechin and Ascorbic Acid Dual Delivery Transferosomes for Managing Alzheimer's Disease: In Vitro and in Vivo Studies

Epigallocatechin-3-gallate (EGCG) and ascorbic acid (AA)-loaded transferosomes (TRANS) were developed for brain delivery. The investigation covered EGCG-TRANS, AA-TRANS, and EGCG-AA-TRANS formulations using the film hydration technique. We analyzed the formed transferosomes to confirm the presence of vesicles loaded with the respective drugs and their performance within a living organism. The sizes of the particles for EGCG-TRANS, AA-TRANS, and EGCG-AA-TRANS were measured correspondingly at 174.2 ± 1.80, 132.7 ± 12.22, and 184.31 ± 9.5 nm. The appearance of diffused rings in the scanning electron microscopic image suggests that the payload has a crystalline structure. The atomic force microscope image displayed minimal surface irregularities, potentially indicating the presence of a lipid layer on the surface. Hemolysis results indicated the safety of the vesicles. The results showed 10.23, 7.21, and 8.20% of hemolysis for EGCG-TRANS, AA-TRANS, and EGCG-AA-TRANS, respectively. In the case of EGCG-AA-TRANS, the release of EGCG was determined to be 61.65% ± 4.61 after 72 h when exposed to phosphate buffer saline (pH 7.4). In vivo studies show a good response against Alzheimer's disease (AD). EGCG-AA-TRANS (82.166%) exhibited a higher percentage of AChE inhibition in comparison to EGCG-TRANS (66.550%) and AA-TRANS (53.466%). Intranasal delivery of EGCG-AA-TRANS resulted in approximately a 5-fold enhancement in memory. Formulation allowed EGCG and AA to accumulate in various organs, including the brain. The results suggest that EGCG-AA-TRANS could be safe and effective for treating AD.

Tea, coffee, and caffeine intake and risk of dementia and Alzheimer's disease: a systematic review and meta-analysis of cohort studies

Background: Limited and conflicting evidence exists for the associations between tea, coffee, and caffeine intake and risk of dementia and Alzheimer's disease (AD). This meta-analysis aimed to elucidate these associations and quantify potential dose-response relationships. Methods: PubMed, EMBASE, and Web of Science were searched up to 11 June 2024 for cohort studies. Random effects models were used to calculate pooled relative risks (RRs) and 95% confidence intervals (CIs), with the dose-response relationship assessed using restricted cubic splines. The Grading of Recommendations Assessment Development and Evaluation (GRADE) tool was used to assess the risk of bias. Results: Our analysis encompassed 38 cohorts, totalling 751 824 participants and 13 017 dementia and 17 341 AD cases. For dementia, compared with the lowest category, the pooled RRs (95% CI) in the highest category of tea, coffee, and caffeine were 0.84 (0.74-0.96, n = 6), 0.95 (0.87-1.02, n = 9), and 0.94 (0.70-1.25, n = 5), with all rated as low certainty in GRADE. For AD, the pooled RRs (95% CI) in the highest category of tea, coffee, and caffeine compared to the lowest category were 0.93 (0.87-1.00, n = 6), 1.01 (0.90-1.12, n = 10), and 1.34 (1.04-1.74, n = 2), with certainty ratings of low, low, and very low, respectively. Dose-response analysis indicated a non-linear relationship between coffee intake (Poverall = 0.04 and Pnonlinear = 0.01) and dementia risk, showing the protective association of risk of dementia with 1 to 3 cups per day of coffee intake. There is a linear association between tea intake and risk of dementia, with a significantly decreased risk of dementia for each 1 cup per day increase in tea consumption (0.96, 95% CI 0.94-0.99, Poverall = 0.01 and Pnonlinear = 0.68). Conclusion: Increased tea consumption was associated with a decreased risk of dementia and AD, and a non-linear relationship was found between coffee and dementia, supporting public health recommendations for dementia prevention.

The Interplay of Protein Aggregation, Genetics, and Oxidative Stress in Alzheimer's Disease: Role for Natural Antioxidants and Immunotherapeutics

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that comprises amyloid-beta protein (Aβ) as a main component of neuritic plaques. Its deposition is considered a trigger for AD pathogenesis, progression, and the clinical symptoms of cognitive impairment. Some distinct pathological features of AD include phosphorylation of tau protein, oxidative stress, and mitochondrial dysfunction. These pathological consequences tend to produce reactive oxygen species (ROS), resulting in the dysregulation of various signaling pathways of neuroinflammation and neurodegeneration. The relationship between the Aβ cascade and oxidative stress in AD pathogenesis is like a "chicken and egg" story, with the etiology of the disease regarding these two factors remaining a question of "which comes first." However, in this review, we have tried our best to clarify the interconnection between these two mechanisms and to show the precise cause-and-effect relationship. Based on the above hallmarks of AD, several therapeutic strategies using natural antioxidants, monoclonal antibodies, and vaccines are employed as anti-Aβ therapy to decrease ROS, Aβ burden, chronic neuroinflammation, and synaptic failure. These natural antioxidants and immunotherapeutics have demonstrated significant neuroprotective effects and symptomatic relief in various in vitro and in vivo models, as well as in clinical trials for AD. However, none of them have received final approval to enter the drug market for mitigating AD. In this review, we extensively elaborate on the pitfalls, assurances, and important crosstalk between oxidative stress and Aβ concerning current anti-Aβ therapy. Additionally, we discuss future strategies for the development of more Aβ-targeted approaches and the optimization of AD treatment and mitigation.

Analysis of the anti-Alzheimer potential of bioactive compounds from Citrus hystrix DC. peel, leaf, and essential oil by network pharmacology

Alzheimer's disease (AD) is the most known neurodegenerative disease, and its prevalence is predicted to increase significantly. Discovering novel drugs and treatments for AD is urgently needed. Drugs from natural products have been preferred lately due to their high potential and low toxicity. Citrus hystrix DC. (kaffir lime; KL) is one such herbal plant that is found abundantly in Southeast Asia with many biological activities. In this study, the potential of bioactive compounds from KL peel, leaf, and essential oil as anti-AD agents was explored using network pharmacology. First, the compounds were identified with KNApSAcK database and related literature. Subsequently, the targets of each corresponding compound were determined with SEA Search Server and Swiss Target Prediction, while the proteins associated with AD were identified using OMIM, GenCLiP3, and DisGeNET. Furthermore, a protein-protein interaction network and a compound-target interaction network were constructed to identify the most crucial proteins and compounds in the network by employing Cytoscape v3.9.1. The study continued with pathway enrichment analysis using STRING v1.7.1, molecular docking with PyRx and SwissDock, and molecular dynamics simulation with YASARA for further confirmation. Our results showed that almost all the secondary metabolites of KL targeted AD-associated genes, with oxypeucedanin and citrusoside A showing the highest anti-AD potential and targeting essential genes, EGFR and MAPK14, respectively. These targets were associated with inflammatory and oxidative stress pathways, indicating the potential mechanism of KL in attenuating AD clinical manifestation.

Neuroprotective Effects of Olive Oil: A Comprehensive Review of Antioxidant Properties

Neurodegenerative diseases are a significant challenge to global healthcare, and oxidative stress plays a crucial role in their development. This paper presents a comprehensive analysis of the neuroprotective potential of olive oil, with a primary focus on its antioxidant properties. The chemical composition of olive oil, including key antioxidants, such as oleuropein, hydroxytyrosol, and oleocanthal, is systematically examined. The mechanisms by which these compounds provide neuroprotection, including counteracting oxidative damage and modulating neuroprotective pathways, are explored. The neuroprotective efficacy of olive oil is evaluated by synthesizing findings from various sources, including in vitro studies, animal models, and clinical trials. The integration of olive oil into dietary patterns, particularly its role in the Mediterranean diet, and its broader implications in neurodegenerative disease prevention are also discussed. The challenges in translating preclinical findings to clinical applications are acknowledged and future research directions are proposed to better understand the potential of olive oil in mitigating the risk of neurodegenerative conditions. This review highlights olive oil not only as a dietary component, but also as a promising candidate in preventive neurology, advocating for further investigation in the context of neurodegenerative diseases.

Epigallocatechin-3-gallate Inhibits LPS/AβO-induced Neuroinflammation in BV2 Cells through Regulating the ROS/TXNIP/NLRP3 Pathway

Neuroinflammation is a key factor in cognitive dysfunction and neurodegenerative diseases such as Alzheimer's disease (AD), so inhibiting neuroinflammation is considered as a potential treatment for AD. Epigallocatechin-3-gallate (EGCG), a polyhydroxyphenol of green tea, has been found to exhibit anti-oxidative, anti-inflammatory and neuroprotective effects. The aim of this study was to investigate the inhibitory effect of EGCG on inflammation and its mechanism. In this study, BV2 cells were simultaneously exposed to lipopolysaccharides (LPS) and the amyloid-β oligomer (AβO) to induce inflammatory microenvironments. Inflammatory cytokines and NLRP3 inflammasome-related molecules were detected by RT-PCR and Western Blot. The results show that EGCG inhibits LPS/AβO-induced inflammation in BV2 cells through regulating IL-1β, IL-6, and TNF-α. Meanwhile, EGCG reduces the activation of the NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome and levels of intracellular ROS in BV2 cells treated with LPS/AβO by affecting the mitochondrial membrane potential (MMP). Further research found that EGCG inhibited MMP through regulating thioredoxin-interacting protein (TXNIP) in LPS/AβO-induced neuroinflammation. In conclusion, EGCG may alleviate LPS/AβO-induced microglial neuroinflammation by suppressing the ROS/ TXNIP/ NLRP3 pathway. It may provide a potential mechanism underlying the anti-inflammatory properties of EGCG for alleviating AD.

Environmental Toxins and Alzheimer's Disease: a Comprehensive Analysis of Pathogenic Mechanisms and Therapeutic Modulation

Alzheimer's disease is a leading cause of mortality worldwide. Inorganic and organic hazards, susceptibility to harmful metals, pesticides, agrochemicals, and air pollution are major environmental concerns. As merely 5% of AD cases are directly inherited indicating that these environmental factors play a major role in disease development. Long-term exposure to environmental toxins is believed to progress neuropathology, which leads to the development of AD. Numerous in-vitro and in-vivo studies have suggested the harmful impact of environmental toxins at cellular and molecular level. Common mechanisms involved in the toxicity of these environmental pollutants include oxidative stress, neuroinflammation, mitochondrial dysfunction, abnormal tau, and APP processing. Increased expression of GSK-3β, BACE-1, TNF-α, and pro-apoptotic molecules like caspases is observed upon exposure to these environmental toxins. In addition, the expression of neurotrophins like BDNF and GAP-43 have been found to be reduced as a result of toxicity. Further, modulation of signaling pathways involving PARP-1, PGC-1α, and MAPK/ERK induced by toxins have been reported to contribute in AD pathogenesis. These pathways are a promising target for developing novel AD therapeutics. Drugs like epigallocatechin-gallate, neflamapimod, salsalate, dexmedetomidine, and atabecestat are in different phases of clinical trials targeting the pathways for possible treatment of AD. This review aims to culminate the correlation between environmental toxicants and AD development. We emphasized upon the signaling pathways involved in the progression of the disease and the therapeutics under clinical trial targeting the altered pathways for possible treatment of AD.

Biosynthesis of Nanoparticles with Green Tea for Inhibition of β-Amyloid Fibrillation Coupled with Ligands Analysis

Background

Inhibition of amyloid β protein fragment (Aβ) aggregation is considered to be one of the most effective strategies for the treatment of Alzheimer's disease. (-)-Epigallocatechin-3-gallate (EGCG) has been found to be effective in this regard; however, owing to its low bioavailability, nanodelivery is recommended for practical applications. Compared to chemical reduction methods, biosynthesis avoids possible biotoxicity and cumbersome preparation processes.

Materials and Methods

The interaction between EGCG and Aβ42 was simulated by molecular docking, and green tea-conjugated gold nanoparticles (GT-Au NPs) and EGCG-Au NPs were synthesized using EGCG-enriched green tea and EGCG solutions, respectively. Surface active molecules of the particles were identified and analyzed using various liquid chromatography-tandem triple quadrupole mass spectrometry methods. ThT fluorescence assay, circular dichroism, and TEM were used to investigate the effect of synthesized particles on the inhibition of Aβ42 aggregation.

Results

EGCG as well as apigenin, quercetin, baicalin, and glutathione were identified as capping ligands stabilized on the surface of GT-Au NPs. They more or less inhibited Aβ42 aggregation or promoted fibril disaggregation, with EGCG being the most effective, which bound to Aβ42 through hydrogen bonding, hydrophobic interactions, etc. resulting in 39.86% and 88.50% inhibition of aggregation and disaggregation effects, respectively. EGCG-Au NPs were not as effective as free EGCG, whereas multiple thiols and polyphenols in green tea accelerated and optimized heavy metal detoxification. The synthesized GT-Au NPs conferred the efficacy of diverse ligands to the particles, with inhibition of aggregation and disaggregation effects of 54.69% and 88.75%, respectively, while increasing the yield, enhancing water solubility, and decreasing cost.

Conclusion

Biosynthesis of nanoparticles using green tea is a promising simple and economical drug-carrying approach to confer multiple pharmacophore molecules to Au NPs. This could be used to design new drug candidates to treat Alzheimer's disease.

Epigallocatechin-3-Gallate attenuates lipopolysacharide-induced pneumonia via modification of inflammation, oxidative stress, apoptosis, and autophagy

BACKGROUND

Pneumonia, the acute inflammation of lung tissue, is multi-factorial in etiology. Hence, continuous studies are conducted to determine the mechanisms involved in the progression of the disease and subsequently suggest effective treatment. The present study attempted to evaluate the effects of Epigallocatechin-3-Gallate (EGCG), an herbal antioxidant, on inflammation, oxidative stress, apoptosis, and autophagy in a rat pneumonia model.

METHODS

Forty male Wistar rats, 5 months old and 250-290 g were divided into four groups including control, EGCG, experimental pneumonia (i/p LPS injection, 1 mg/kg), and experimental pneumonia treated with EGCG (i/p, 15 mg/kg, 1 h before and 3 h after LPS instillation). Total cell number in the bronchoalveolar lavage fluid, inflammation (TNF-a, Il-6, IL-1β, and NO), oxidative stress (Nrf2, HO-1, SOD, CAT, GSH, GPX, MDA, and TAC), apoptosis (BCL-2, BAX, CASP-3 and CASP-9), and autophagy (mTOR, LC3, BECN1) were evaluated.

RESULTS

The findings demonstrated that EGCG suppresses the LPS-induced activation of inflammatory pathways by a significant reduction of inflammatory markers (p-value < 0.001). In addition, the upregulation of BCL-2 and downregulation of BAX and caspases revealed that EGCG suppressed LPS-induced apoptosis. Furthermore, ECGC suppressed oxidative injury while promoting autophagy in rats with pneumonia (p-value < 0.05).

CONCLUSION

The current study revealed that EGCG could suppress inflammation, oxidative stress, apoptosis, and promote autophagy in experimental pneumonia models of rats suggesting promising therapeutical properties of this compound to be used in pneumonia management.

Role of Natural Compounds Modulating Heme Catabolic Pathway in Gut, Liver, Cardiovascular, and Brain Diseases

The crucial physiological process of heme breakdown yields biliverdin (BV) and bilirubin (BR) as byproducts. BV, BR, and the enzymes involved in their production (the "yellow players-YP") are increasingly documented as endogenous modulators of human health. Mildly elevated serum bilirubin concentration has been correlated with a reduced risk of multiple chronic pro-oxidant and pro-inflammatory diseases, especially in the elderly. BR and BV per se have been demonstrated to protect against neurodegenerative diseases, in which heme oxygenase (HMOX), the main enzyme in the production of pigments, is almost always altered. HMOX upregulation has been interpreted as a tentative defense against the ongoing pathologic mechanisms. With the demonstration that multiple cells possess YP, their propensity to be modulated, and their broad spectrum of activity on multiple signaling pathways, the YP have assumed the role of an adjustable system that can promote health in adults. Based on that, there is an ongoing effort to induce their activity as a therapeutic option, and natural compounds are an attractive alternative to the goal, possibly requiring only minimal changes in the life style. We review the most recent evidence of the potential of natural compounds in targeting the YP in the context of the most common pathologic condition of adult and elderly life.

Memory Recovery Effect of a New Bioactive Innovative Combination in Rats with Experimental Dementia

Alzheimer's disease manifests as a complex pathological condition, with neuroinflammation, oxidative stress and cholinergic dysfunction being a few of the many pathological changes. Due to the complexity of the disease, current therapeutic strategies aim at a multitargeted approach, often relying on a combination of substances with versatile and complementary effects. In the present study, a unique combination of α-lipoic acid, citicoline, extracts of leaves from olive tree and green tea, vitamin D3, selenium and an immune-supporting complex was tested in scopolamine-induced dementia in rats. Using behavioral and biochemical methods, we assessed the effects of the combination on learning and memory, and elucidated the mechanisms of these effects. Our results showed that, compared to its components, the experimental combination was most efficient in improving short- and long-term memory as assessed by the step-through method as well as spatial memory as assessed by T-maze and Barnes maze underlined by decreases in AChE activity (p < 0.05) and LPO (p < 0.001), increases in SOD activity in the cortex (p < 0.05) and increases in catalase (p < 0.05) and GPx (p < 0.01) activities and BDNF (p < 0.001) and pCREB (p < 0.05) levels in the hippocampus. No significant histopathological changes or blood parameter changes were detected, making the experimental combination an effective and safe candidate in a multitargeted treatment of AD.