Quercetin attenuates inflammation in LPS-induced lung epithelial cells via the Nrf2 signaling pathway

The Effects of Quercetin on Vascular Endothelium, Inflammation, Cardiovascular Disease and Lipid Metabolism-A Review

Quercetin is a naturally occurring flavonoid of plant origin. This naturally occurring polyphenolic compound is generally known for its antioxidant and anti-inflammatory properties and has been reported to be a factor in improving the antioxidant defense system, lipid metabolism, and reducing the incidence of cardiovascular and inflammatory diseases. In this article, we will take a closer look at quercetin-what it is, what properties it has, what health benefits it can bring, and in which products it can be found. Thanks to its wide spectrum of action, quercetin is gaining popularity as an ingredient in dietary supplements, as well as an element of a healthy diet supporting overall health.

Nutritional Support of Chronic Obstructive Pulmonary Disease

Background: COPD is a heterogenous disease of the respiratory tract caused by diverse genetic factors along with environmental and lifestyle-related effects such as industrial dust inhalation and, most frequently, cigarette smoking. These factors lead to airflow obstruction and chronic respiratory symptoms. Additionally, the increased risk of infections exacerbates airway inflammation in COPD patients. As a consequence of the complex pathomechanisms and difficulty in treatment, COPD is among the leading causes of mortality both in the western countries and in the developing world. Results: The management of COPD is still a challenge for the clinicians; however, alternative interventions such as smoking cessation and lifestyle changes from a sedentary life to moderate physical activity with special attention to the diet may ameliorate patients' health. Here, we reviewed the effects of different dietary components and supplements on the conditions of COPD. Conclusions: COPD patients are continuously exposed to heavy metals, which are commonly present in cigarette smoke and polluted air. Meanwhile, they often experience significant nutrient deficiencies, which affect the detoxification of these toxic metals. This in turn can further disrupt nutritional balance by interfering with the absorption, metabolism, and utilization of essential micronutrients. Therefore, awareness and deliberate efforts should be made to check levels of micronutrients, with special attention to ensuring adequate levels of antioxidants, vitamin D, vitamin K2, magnesium, and iron, as these may be particularly important in reducing the risk of COPD development and limiting disease severity.

Comprehensive Metabolomics Profiling and Bioactivity Study of Lycium shawii (Awsaj) Extracts with Particular Emphasis on Potential Anti-Malarial Properties

Background/Objectives: Although malaria is one of the oldest known human diseases, it continues to be a major global health challenge. According to UNICEF, the global malaria mortality rate exceeded 600,000 annually in 2022, which includes more than 1000 children dying each day. This study aimed to investigate the comprehensive chemical profile and biological activities, particularly the antimalarial activity, of Lycium shawii (Awsaj), a shrub traditionally used in the Arabian Peninsula, Middle East, India, and Africa to treat a myriad of ailments. Methods: Crude extracts of L. shawii were prepared using water, ethanol, methanol, and acetone. Nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) were utilized to perform untargeted metabolomics to maximize metabolite detection and tentatively identify bioactive phytochemicals. The total phenolic content (TPC) was measured for each extract, and bioassays were conducted to evaluate their antimalarial, antibacterial, and anti-inflammatory activities, particularly those of the water extract, which is the traditional method of consumption in Arabian folk medicine. Results: A total of 148 metabolites were detected, 45 of which were classified as phytochemicals. The bioassays revealed that the water extract that is traditionally used showed promising antimalarial potential by significantly inhibiting β-hematin formation in vitro at 1 mg/mL (with an absorbance of 0.140 ± 0.027). This is likely due to the rich presence of quinoline in the aqueous extract among several other bioactive phytochemicals, such as phenylpropanoids, alkaloids, flavonoids, and benzenoids. However, their anti-inflammatory and antibacterial activities were found to be weak, with only a minor inhibition of nitric oxide (NO) production in LPS-induced RAW 264.7 cells at a concentration of 500 µg/mL and weak antibacterial effects against pathogens like P. aeruginosa, MRSA, A. baumannii, and K. pneumoniae with an MIC of 500 μg/mL. The results also revealed that the methanolic extract had the highest TPC at 26.265 ± 0.005 mg GAE/g. Conclusions: The findings support the traditional medicinal use of L. shawii and highlight its potential as a source of novel therapeutic compounds, particularly for treating malaria. This study encourages further research to isolate and develop effective plant-based anti-malarial agents.

The Role of Quercetin, a Flavonoid in the Management of Pathogenesis Through Regulation of Oxidative Stress, Inflammation, and Biological Activities

Quercetin, a flavonoid found in vegetables and fruits, has been extensively studied for its health benefits and disease management. Its role in the prevention of various pathogenesis has been well-documented, primarily through its ability to inhibit oxidative stress, inflammation, and enhance the endogenous antioxidant defense mechanisms. Electronic databases such as Google Scholar, Scopus, PubMed, Medline, and Web of Science were searched for information regarding quercetin and its role in various pathogeneses. The included literature comprised experimental studies, randomized controlled trials, and epidemiological studies related to quercetin, while editorials, case analyses, theses, and letters were excluded. It has been reported to have a wide range of health benefits including hepatoprotective, antidiabetic, anti-obesity, neuroprotective, cardioprotective, wound healing, antimicrobial, and immunomodulatory effects, achieved through the modulation of various biological activities. Additionally, numerous in vitro and in vivo studies have shown that quercetin's efficacies in cancer management involve inhibiting cell signaling pathways, such as inflammation, cell cycle, and angiogenesis, activating cell signaling pathways including tumor suppressor genes, and inducing apoptosis. This review aims to provide a comprehensive understanding of the health benefits of quercetin in various pathogeneses. Additionally, this review outlines the sources of quercetin, nanoformulations, and its applications in health management, along with key findings from important clinical trial studies. Limited clinical data regarding quercetin's safety and mechanism of action are available. It is important to conduct more clinical trials to gain a deeper understanding of the disease-preventive potential, mechanisms of action, safety, and optimal therapeutic dosages. Furthermore, more research based on nanoformulations should be performed to minimize/overcome the hindrance associated with bioavailability, rapid degradation, and toxicity.

Quercetin, the new stress buster: Investigating the transcriptional and behavioral effects of this flavonoid on multiple stressors using Lymnaea stagnalis

Growing evidence suggests that a flavonoid-rich diet can prevent or reverse the effects of stressors, although the underlying mechanisms remain poorly understood. One common and abundant flavonoid found in numerous foods is quercetin. This study utilizes the pond snail Lymnaea stagnalis, a valid model organism for learning and memory, and a simple but robust learning paradigm-operant conditioning of aerial respiration-to explore the behavioral and transcriptional effects of different stressors on snails' cognitive functions and to investigate whether quercetin exposure can prevent stress effects on learning and memory formation. Our findings demonstrate that three different stressors-severe food deprivation, lipopolysaccharide injection (an inflammatory challenge), and fluoride exposure (a neurotoxic agent)-block memory formation for operant conditioning and affect the expression levels of key targets related to stress response, energy balance, and immune response in the snails' central ring ganglia. Remarkably, exposing snails to quercetin for 1 h before stress presentation prevents these effects at both the behavioral and transcriptional levels, demonstrating the potent stress-preventive properties of quercetin. Despite the evolutionary distance from humans, L. stagnalis has proven to be a valuable model for studying conserved mechanisms by which bioactive compounds like quercetin mitigate the adverse effects of various stressors on cognitive functions across species. Moreover, these findings offer insights into quercetin's potential for mitigating stress-induced physiological and cognitive impairments.

Naringenin counteracts LPS-induced inflammation and immune deficits in chicken thymus by alleviating mtROS/ferroptosis levels

Naringenin is a flavonoid with significant anti-inflammatory and antioxidant properties. Mitochondrial dynamics, the mitochondrial respiratory chain, and mtROS are closely related to each other and regulate various biological processes. Ferroptosis is closely related to inflammatory responses and immune function in multiple tissues and organs. However, whether naringenin can alleviate LPS-induced inflammation and immune disorders in the chicken thymus via mtROS/ferroptosis has not been reported. Therefore, in this study, we constructed chicken thymus and MSB-1 cell models of LPS and naringenin based on screening for naringenin concentrations that have positive effects on inflammation and immune function to further investigate the anti-inflammatory, antiferroptosis, and maintenance of the immune function of naringenin. The results showed that 40 mg/kg naringenin alleviated LPS-induced tissue damage, elevated serum inflammatory factors, and decreased serum immune factors. The mechanism by which naringenin attenuates mtROS release by alleviating the imbalance of mitochondrial dynamics and the blockage of the respiratory chain. The effect of naringenin on alleviating LPS-induced lipid peroxidation, disruption of the GSH/GSSG system, iron overload, and GPx4 inactivation, thereby attenuating ferroptosis in thymus tissue, was inhibited by the addition of mtROS activators. In conclusion, naringenin alleviates LPS-induced ferroptosis in chicken thymus by attenuating mtROS release.

Sensing of Quercetin With Cobalt-Doped Manganese Nanosystems by Electrochemical Method

BACKGROUND

The pressing need for precise, quick, and affordable detection of diverse biomolecules has led to notable developments in the realm of biosensors. Quercetin, a biomolecule rich in flavonoids predominantly found in our diet, is sensed by the electrochemical method. The electrochemical properties show remarkable improvement when Mn2O3 (MO) is doped with cobalt (Co).  Aim: This study aimed to investigate the biomolecule sensing of quercetin using Co-doped MO by electrochemical method.  Materials and methods: Co-doped MO nanospheres were prepared by hydrothermal method. The crystal structure of the synthesized material was evaluated by using X-ray diffraction analysis. The sample morphology was assessed by using field emission scanning electron microscopy (FE-SEM) techniques. The cyclic voltammetry technique was used for the detection of quercetin biomolecules.  Results: The synthesized Co-doped MO appeared to be spherical in morphology in FE-SEM. Energy-dispersive X-ray spectroscopy showed the only presence of Co, Mn, and O, which confirmed the purity of the sample. The modified electrode sensed the biomolecule with a higher current of 7.35 µA than the bare glassy carbon electrode of 6.1 µA.

CONCLUSION

The Co-doped MO exhibited enhanced conductivity, reactivity, and electrochemical performance. This tailored approach will help in the optimization of material properties toward specific biomolecule sensing applications.