Quercetin reduces high-fat diet-induced fat accumulation in the liver by regulating lipid metabolism genes

Tao-Hong-Si-Wu-Tang improves thioacetamide-induced liver fibrosis by reversing ACSL4-mediated lipid accumulation and promoting mitophagy

ETHNOPHARMACOLOGICAL RELEVANCE

Liver fibrosis is a generic fibrous scarring event resulting from accumulation of extracellular matrix (ECM) proteins, easily progressing to end-stage liver diseases. Tao-Hong-Si-Wu-Tang (THSWT) is a traditional Chinese medicine formula applied in clinics to treat gynecological and chronic liver diseases. However, the role of THSWT on thioacetamide (TAA)-induced hepatic fibrosis and the specific mechanisms remains unclear.

AIM OF THE STUDY

To investigate the improving effects of THSWT on TAA-insulted hepatic fibrosis and the underlying mechanisms.

MATERIALS AND METHODS

UHPLC-MS/MS was performed to explore the chemical characterization of THSWT. Mice were orally administered with THSWT once daily for 6 weeks along with TAA challenge. Liver function was reflected through serum biomarkers and histopathological staining. RNA sequencing, non-targeted metabolomics and molecular biology experiments were applied to investigate the underlying mechanisms.

RESULTS

THSWT profoundly repaired lipid metabolism dysfunction and blocked collagen accumulation both in TAA-stimulated mice and in hepatocytes. Results of RNA sequencing and non-targeted metabolomics revealed that the anti-fibrotic effects of THSWT mostly relied on lipid metabolism repairment by increasing levels of acetyl-CoA, phosphatidylcholine, phosphatidylethanolamine, lysophosphatidylcholine and lysophosphatidylethanolamine, and decreasing relative abundances of acyl-CoA, total cholesterol, diacylglycerol, triacylglycerol and phosphatidylinositol. Mechanically, long-chain acyl-CoA synthetases 4 (ACSL4) was a key profibrotic target both in human and mice by disrupting lipid oxidation and metabolism in hepatic mitochondria. THSWT effectively blocked ACSL4 and promoted mitophagy to reverse above outcomes, which was verified by mitophagy depletion.

CONCLUSION

THSWT may be a promising therapeutic option for treating hepatic fibrosis and its complications by modulating lipid metabolism and promoting mitophagy in livers.

Therapeutic Potential of Quercetin as an Antioxidant for Bone-Muscle-Tendon Regeneration and Aging

Quercetin (QC), a naturally occurring bioflavonoid found in various fruits and vegetables, possesses many potential health benefits, primarily attributed to its robust antioxidant properties. The generation of oxidative stress in bone cells is a key modulator of their physiological behavior. Moreover, oxidative stress status influences the pathophysiology of mineralized tissues. Increasing scientific evidence demonstrates that manipulating the redox balance in bone cells might be an effective technique for developing bone disease therapies. The QC antioxidant abilities in skeletal muscle significantly enhance muscle regeneration and reduce muscle atrophy. In addition, QC has been shown to have protective effects against oxidative stress, inflammation, apoptosis, and matrix degradation in tendons, helping to maintain the structural integrity and functionality of tendons. Thus, the antioxidant properties of QC might be crucial for addressing age-related musculoskeletal disorders like osteoporosis, sarcopenia, and tendon-related inflammatory conditions. Understanding how QC influences redox signaling pathways involved in musculoskeletal disorders, including their effect on bone, muscle, and tendon differentiation, might provide insights into the diverse advantages of QC in promoting tissue regeneration and preventing cellular damage. Therefore, this study reviewed the intricate relationship among oxidative stress, inflammation, and tissue repair, affected by the antioxidative abilities of QC, in age-related musculoskeletal tissues to improve the overall health of bones, muscles, and tendons of the skeletal system. Also, reviewing the ongoing clinical trials of QC for musculoskeletal systems is encouraging. Given the positive effect of QC on musculoskeletal health, further scientific investigations and controlled human intervention studies are necessary to explore the therapeutic potential to its optimum strength.

Amplification of Cardioprotective Response of Remote Ischemic Preconditioning in Rats by Quercetin: Potential Role of Activation of mTOR-dependent Autophagy and Nrf2

OBJECTIVES

Noninvasive remote ischemic preconditioning (RIPC) is a practical, acceptable, and feasible conditioning technique reported to provide cardioprotection in myocardial ischemia-reperfusion injury (MIRI). It has been well-reported that quercetin possesses antioxidant and anti-inflammatory properties. This study investigates the modification of the cardioprotective response of RIPC by quercetin.

METHODS

Adult Wistar rats were randomized into 12 groups of six animals each. MIRI was induced by subjecting the isolated hearts of Wistar rats to global ischemia for 30 min, succeeded by reperfusion of 120 min after mounting on the Langendorff PowerLab apparatus. Hind limb RIPC was applied in four alternate cycles of ischemia and reperfusion of 5 min each by tying the pressure cuff before isolation of hearts.

RESULTS

MIRI was reflected by significantly increased infarct size, LDH-1, and CK-MB, TNF-α, TBARS, and decreased GSH, catalase, and hemodynamic index, and modulated Nrf2. Pretreatment of quercetin (25 and 50 mg/kg; i.p.) significantly attenuated the MIRI-induced cardiac damage and potentiated the cardioprotective response of RIPC at the low dose. Pretreatment of ketamine (10 mg/kg; i.p.), an mTOR-dependent autophagy inhibitor, significantly abolished the cardioprotective effects of quercetin and RIPC.

CONCLUSIONS

The findings highlight the modification of the cardioprotective effect of RIPC by quercetin and that quercetin protects the heart against MIRI through multiple mechanisms, including mTOR-dependent activation of autophagy and Nrf-2 activation.

Flavonoids, gut microbiota, and host lipid metabolism

Flavonoids are widely distributed in nature and have a variety of beneficial biological effects, including antioxidant, anti-inflammatory, and anti-obesity effects. All of these are related to gut microbiota, and flavonoids also serve as a bridge between the host and gut microbiota. Flavonoids are commonly used to modify the composition of the gut microbiota by promoting or inhibiting specific microbial species within the gut, as well as modifying their metabolites. In turn, the gut microbiota extensively metabolizes flavonoids. Hence, this reciprocal relationship between flavonoids and the gut microbiota may play a crucial role in maintaining the balance and functionality of the metabolism system. In this review, we mainly highlighted the biological effects of antioxidant, anti-inflammatory and antiobesity, and discussed the interaction between flavonoids, gut microbiota and lipid metabolism, and elaborated the potential mechanisms on host lipid metabolism.

Targeting dysregulated lipid metabolism in the tumor microenvironment

The reprogramming of lipid metabolism and its association with oncogenic signaling pathways within the tumor microenvironment (TME) have emerged as significant hallmarks of cancer. Lipid metabolism is defined as a complex set of molecular processes including lipid uptake, synthesis, transport, and degradation. The dysregulation of lipid metabolism is affected by enzymes and signaling molecules directly or indirectly involved in the lipid metabolic process. Regulation of lipid metabolizing enzymes has been shown to modulate cancer development and to avoid resistance to anticancer drugs in tumors and the TME. Because of this, understanding the metabolic reprogramming associated with oncogenic progression is important to develop strategies for cancer treatment. Recent advances provide insight into fundamental mechanisms and the connections between altered lipid metabolism and tumorigenesis. In this review, we explore alterations to lipid metabolism and the pivotal factors driving lipid metabolic reprogramming, which exacerbate cancer progression. We also shed light on the latest insights and current therapeutic approaches based on small molecular inhibitors and phytochemicals targeting lipid metabolism for cancer treatment. Further investigations are worthwhile to fully understand the underlying mechanisms and the correlation between altered lipid metabolism and carcinogenesis.

Effect of PENN-DIABEX, a novel polyherbal formulation, in high fat diet streptozotocin-induced diabetic rats

Diabetes, a chronic metabolic disorder affecting millions worldwide, presents a significant health challenge characterized by impaired glucose regulation and potential complications. This study examines the antidiabetic effects of a polyherbal formulation (PENN-DIABEX) prepared from five different medicinal plant extracts. The objective is to ascertain its efficacy in managing streptozotocin (STZ) induced diabetes in rats. To accomplish this, six distinct groups of rats were involved five with induced diabetes and one serving as a normal control. Among the diabetic groups, one received no treatment, functioning as the diabetic control group. The remaining three groups were administered PHF in three different doses while the 6th group was given metformin. On the last day of the experiment, all rats were sacrificed, and blood samples were taken in collecting tubes to analyze blood biochemical parameters. Additionally, tissue samples from the liver, kidney, and pancreas were preserved in formalin solution for subsequent histopathological activity. The results of the study revealed that treatment with PHF in diabetic rats led to a significant (P < 0.01) improvement in fasting blood glucose levels (FBG), glycated hemoglobin (HbA1c), and various biochemical markers including LFTs, RFTs, and lipid profiling. Furthermore, the histology of the liver, kidney, and pancreas indicated that the formulation did not induce any metabolic toxicity. Comparative analysis of the antidiabetic effects of PHF with those of metformin, revealed that the PHF showed better results than the standard drug. This suggests its potential utilization as a safer and alternative approach in the treatment of diabetes.

Effects of Quercetin Nanoemulsion on Cholesterol Efflux and MicroRNA-33/34a Expression in the Liver of Mice Fed with a High-Cholesterol Diet

Quercetin is a flavonoid widely present in plants; despite its beneficial physiological activity, it exhibits considerably low bioavailability. Nanoemulsion technology is used for improving the bioavailability of lipophilic phenolic compounds. This study aimed to investigate the potential effects of quercetin nanoemulsion (QN) on regulating the microRNA (miR)-33/34a pathway involved in cholesterol efflux in the liver of mice fed with a high-cholesterol (HC) diet. Subsequently, C57BL/6J mice were divided into four groups and fed a normal chow diet, HC diet supplemented with 1% cholesterol and 0.5% cholic acid, or HC diet supplemented with 0.05% QN or 0.1% QN for 6 weeks. Serum and hepatic lipid profiles were assayed using commercial enzymatic kits. Gene expression and miR levels were quantified using real-time quantitative reverse transcription polymerase chain reaction, and adenosine monophosphate-activated protein kinase (AMPK) activity was measured using an AMPK Kinase Assay kit. QN supplementation improved serum and liver lipid profiles. QN upregulated the mRNA levels of adenosine triphosphate (ATP)-binding cassette subfamily A1, ATP-binding cassette subfamily G1, and scavenger receptor class B type 1, which are related to cholesterol efflux. In the QN group, the hepatic AMPK activity increased, whereas miR-33, and miR-34a expression levels decreased. These results suggest that QN may enhance cholesterol efflux, at least partly through modulating AMPK activity and miR-33/34a expression in the liver.

Quercetin and Related Analogs as Therapeutics to Promote Tissue Repair

Quercetin is a polyphenol of the flavonoid class of secondary metabolites that is widely distributed in the plant kingdom. Quercetin has been found to exhibit potent bioactivity in the areas of wound healing, neuroprotection, and anti-aging research. Naturally found in highly glycosylated forms, aglycone quercetin has low solubility in aqueous environments, which has heavily limited its clinical applications. To improve the stability and bioavailability of quercetin, efforts have been made to chemically modify quercetin and related flavonoids so as to improve aqueous solubility while retaining bioactivity. In this review, we provide an updated overview of the biological properties of quercetin and proposed mechanisms of actions in the context of wound healing and aging. We also provide a description of recent developments in synthetic approaches to improve the solubility and stability of quercetin and related analogs for therapeutic applications. Further research in these areas is expected to enable translational applications to improve ocular wound healing and tissue repair.

Taurine supplementation reduces adiposity and hepatic lipid metabolic activity in adult offspring following maternal cafeteria diet

Maternal taurine supplementation has been shown to exert protective effects following a maternal obesogenic diet on offspring growth and metabolism. However, the long-term effects of maternal cafeteria diet on adiposity, metabolic profile, and hepatic gene expression patterns following supplementation of taurine in adult offspring remains unclear. In this study, we hypothesized that exposure to maternal taurine supplementation would modulate the effects of maternal cafeteria diet by reducing adiposity and hepatic gene expression patterns involved in lipid metabolism in adult offspring. Female Wistar rats were fed a control diet, control diet supplemented with 1.5% taurine in drinking water, cafeteria diet (CAF) or CAF supplemented with taurine (CAFT) from weaning. After 8 weeks, all animals were mated and maintained on the same diets during pregnancy and lactation. After weaning, all offspring were fed with control chow diet until the age of 20 weeks. Despite similar body weights, CAFT offspring had significantly lower fat deposition and body fat when compared with CAF offspring. Microarray analysis revealed that genes (Akr1c3, Cyp7a1, Hsd17b6, Cd36, Acsm3, and Aldh1b1) related to steroid hormone biosynthesis, cholesterol metabolism, peroxisome proliferator-activated receptor signaling pathway, butanoate metabolism, and fatty acid degradation were down-regulated in CAFT offspring. The current study shows that exposure to maternal cafeteria diet promoted adiposity and taurine supplementation reduced lipid deposition and in both male and female offspring and led to alterations in hepatic gene expression patterns, reducing the detrimental effects of maternal cafeteria diet.

Quercetin Alleviates Inflammation and Energy Deficiency Induced by Lipopolysaccharide in Chicken Embryos

Energy deficiency causes multiple organ dysfunctions after LPS induction. Quercetin is a phenolic compound found in herbal medicines. However, the effects of quercetin in alleviating LPS-induced energy deficiency remain unclear. In the present study, an in vivo LPS-induced inflammation model was established in chicken embryos. Specific pathogen-free chicken embryos (n = 120) were allocated to control, PBS with or without ethanol, quercetin (10, 20, or 40 nmol, respectively), and LPS (125 ng/egg) with or without quercetin groups. Fifteen day old embryonated eggs were injected with the abovementioned solutions via the allantoic cavity. On embryonic day 19, the tissues of the embryos were collected for histopathological examination using frozen oil red O staining, RNA extraction, real-time quantitative polymerase chain reaction, and immunohistochemical investigations. The glycogen and lipid contents in the liver increased after LPS stimulation as compared with the PBS group, whereas quercetin decreased the accumulation as compared with the LPS group. The mRNA expressions of AMPKα1 and AMPKα2 in the duodena, ceca, and livers were upregulated after LPS induction as compared with the PBS group, while quercetin could downregulate these expressions as compared with the LPS group. The immunopositivity of AMPKα2 in the villus, crypt, lamina propria, tunica muscularis, and myenteric plexus in the duodena and in the cytoplasms of hepatocytes significantly increased after LPS induction when compared with the PBS group (p < 0.01), whereas the immunopositivity to AMPKα2 in the quercetin treatment group significantly decreased when compared with the LPS group (p < 0.01 or p < 0.05). The LPS-induced high expressions of transcription factor PPARα and glucose transporter (SGLT1) were blocked by quercetin in the duodena, ceca, and livers. Quercetin treatment improved the LPS-induced decrease in APOA4 in the duodena, ceca, and livers. The mRNA expression of PEPT1 in the duodena and ceca increased after LPS challenge, whereas quercetin could downregulate PEPT1 gene expression. These data demonstrate that quercetin improved the energy deficiency induced by LPS in chicken embryos. The LPS-induced inflammation model was established to avoid the effect of LPS exposure from the environment and intestinal flora. The results form the basis the administration of quercetin pretreatment (in ovo infection) to improve the energy state of chicken embryos and improve the inflammation response.

Biflavonoid quercetin protects against cyclophosphamide-induced organ toxicities via modulation of inflammatory cytokines, brain neurotransmitters, and astrocyte immunoreactivity

BACKGROUND

Cyclophosphamide use has been associated with increased oxidative stress in cells and tissues. Quercetin's antioxidative properties make it of potential benefit in such conditions of oxidative stress.

OBJECTIVE

To assess quercetin's ability to mitigate cyclophosphamide-induced organ toxicities in rats.

METHODS

Sixty rats were assigned into six groups. Groups A and D served as normal and cyclophosphamide control and were fed standard rat chow, groups B and E were fed quercetin supplemented diet (100 mg/kg of feed), while those in groups C and F were fed quercetin at 200 mg/kg of feed. Groups A-C received intraperitoneal (ip) normal saline on days 1 and 2, while D-F received ip cyclophosphamide (150 mg/kg/day on days 1 and 2). On day 21, behavioural tests were carried out, animals were sacrificed and blood samples taken. Organs were processed for histological study.

RESULTS

Quercetin reversed cyclophosphamide-induced decrease in body weight, food intake and total antioxidant capacity, and increase in lipid peroxidation (p = 0.001), It also reversed derangement in levels of liver transaminase, urea, creatinine and proinflammatory cytokines (p = 0.001). Improvement in working-memory and anxiety-related behaviours were also observed. Finally, quercetin reversed alterations in levels of acetylcholine, dopamine and brain-derived neurotropic factor (p = 0.021); while reducing serotonin levels and astrocyte immunoreactivity.

CONCLUSION

Quercetin shows significant ability to protect against cyclophosphamide-induced changes in rats.

Quercetin inhibits body weight gain and adipogenesis via matrix metalloproteinases in mice fed a high-fat diet

BACKGROUND/OBJECTIVES

Limited studies reported that quercetin inhibited adipogenesis and neovascularization by inhibiting matrix metalloproteinases (MMPs) activity, but such mechanisms have not been elucidated in animal experiments. In this study, we investigated the inhibitory effects of quercetin on weight gain and adipose tissue growth through the regulation of mRNA expressions of adipogenic transcription factors and MMPs in mice fed a high-fat diet (HFD).

MATERIALS/METHODS

Five-wk-old C57BL/6J mice were fed a normal diet (ND), HFD, HFD containing 0.05% of quercetin (HFQ0.05), or HFD containing 0.15% of quercetin (HFQ0.15) for 16 wks. Glycerol-3-phosphate dehydrogenase (GPDH) activity was measured using a commercial kit. The mRNA expressions of transcription factors related to adipocyte differentiation were determined by real-time polymerase chain reaction (PCR). The mRNA expressions of MMPs and concentrations of MMPs were measured by real-time PCR and enzyme-linked immunosorbent assay kit, respectively.

RESULTS

Quercetin intake reduced body weight gain and epididymal adipose tissue weights (P < 0.05). GPDH activity was higher in the HFD group than in the ND group but lower in the quercetin groups (P < 0.05). The mRNA expressions of CCAAT/enhancer binding protein β (C/EBPβ), C/EBPα, peroxisome proliferator-activated receptor γ, and fatty acid-binding protein 4 were lower in the quercetin groups than in the HFD group (P < 0.05). Similarly, the mRNA expression and concentrations of MMP-2 and MMP-9 were significantly lower in the quercetin groups than in the HFD group (P < 0.05).

CONCLUSION

The study confirms that quercetin suppresses body weight gain and adipogenesis by inhibiting transcription factors related to adipocyte differentiation and MMPs (MMP-2 and MMP-9), in mice fed a HFD.

Sarcopenic Obesity: Involvement of Oxidative Stress and Beneficial Role of Antioxidant Flavonoids

Sarcopenic obesity, which refers to concurrent sarcopenia and obesity, is characterized by decreased muscle mass, strength, and performance along with abnormally excessive fat mass. Sarcopenic obesity has received considerable attention as a major health threat in older people. However, it has recently become a health problem in the general population. Sarcopenic obesity is a major risk factor for metabolic syndrome and other complications such as osteoarthritis, osteoporosis, liver disease, lung disease, renal disease, mental disease and functional disability. The pathogenesis of sarcopenic obesity is multifactorial and complicated, and it is caused by insulin resistance, inflammation, hormonal changes, decreased physical activity, poor diet and aging. Oxidative stress is a core mechanism underlying sarcopenic obesity. Some evidence indicates a protective role of antioxidant flavonoids in sarcopenic obesity, although the precise mechanisms remain unclear. This review summarizes the general characteristics and pathophysiology of sarcopenic obesity and focuses on the role of oxidative stress in sarcopenic obesity. The potential benefits of flavonoids in sarcopenic obesity have also been discussed.

Targeting mTOR/YY1 signaling pathway by quercetin through CYP7A1-mediated cholesterol-to-bile acids conversion alleviated type 2 diabetes mellitus induced hepatic lipid accumulation

BACKGROUND

Hepatic lipid accumulation was a major promoter for the further development of non-alcoholic fatty liver disease (NAFLD) in type 2 diabetes (T2DM). mTOR/YY1 signaling pathway regulated many metabolic processes in different organs, and played an important role in hepatic lipid metabolism. Thus, targeting mTOR/YY1 signaling pathway might be a novel therapeutic strategy of T2DM-associated NALFD.

PURPOSE

To investigate the effects and the mechanism of quercetin against T2DM-associated NAFLD.

STUDY DESIGN AND METHODS

The combine abilities of 24 flavonoid compounds with mTOR were detected by computer virtual screening (VS) and molecular modeling. mTOR/YY1 signaling pathway was examined in the liver of db/db mice, and high glucose (HG) and free fatty acid (FFA) co-cultured HepG2 cells. YY1 overexpression lentivirus vector and mTOR specific inhibitor rapamycin were used to further identify the indispensable role of mTOR/YY1 signaling pathway in quercetin's amelioration effect of hepatic lipid accumulation in vitro. Clinical studies, luciferase assay and chromatin immunoprecipitation (ChIP) assay were all carried out to investigate the potential mechanisms by which quercetin exerted its amelioration effect of hepatic lipid accumulation.

RESULTS

Quercetin had the strongest ability to combine with mTOR and could competitively occupy its binding pocked. Along with the alleviated hepatic injury by quercetin, mTOR/YY1 signaling pathway was down-regulated in vivo and in vitro. However, the alleviation effect of quercetin against hepatic lipid accumulation was inhibited by YY1 overexpression in vitro. Mechanistically, the down-regulated nuclear YY1 induced by quercetin directly bound to CYP7A1 promoter and activated its transcription, resulting in the restoration of cholesterol homeostasis via the conversion of cholesterol-to-bile acids (BAs).

CONCLUSION

The hepatoprotective effect of quercetin on T2DM-associated NAFLD was linked to the restoration of cholesterol homeostasis by the conversion of cholesterol-to-BAs via down-regulating mTOR/YY1 signaling pathway, leading to the increased CYP7A1 activity.

Bio-Actives from Natural Products with Potential Cardioprotective Properties: Isolation, Identification, and Pharmacological Actions of Apigenin, Quercetin, and Silibinin

Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality worldwide. As a result, pharmaceutical and non-pharmaceutical interventions modifying risk factors for CVDs are a top priority of scientific research. Non-pharmaceutical therapeutical approaches, including herbal supplements, have gained growing interest from researchers as part of the therapeutic strategies for primary or secondary prevention of CVDs. Several experimental studies have supported the potential effects of apigenin, quercetin, and silibinin as beneficial supplements in cohorts at risk of CVDs. Accordingly, this comprehensive review focused critically on the cardioprotective effects/mechanisms of the abovementioned three bio-active compounds from natural products. For this purpose, we have included in vitro, preclinical, and clinical studies associated with atherosclerosis and a wide variety of cardiovascular risk factors (hypertension, diabetes, dyslipidemia, obesity, cardiac injury, and metabolic syndrome). In addition, we attempted to summarize and categorize the laboratory methods for their isolation and identification from plant extracts. This review unveiled many uncertainties which are still unexplored, such as the extrapolation of experimental results to clinical practice, mainly due to the small clinical studies, heterogeneous doses, divergent constituents, and the absence of pharmacodynamic/pharmacokinetic analyses.

Quercetin and Its Derivative Counteract Palmitate-Dependent Lipotoxicity by Inhibiting Oxidative Stress and Inflammation in Cardiomyocytes

Cardiac lipotoxicity plays an important role in the pathogenesis of obesity-related cardiovascular disease. The flavonoid quercetin (QUE), a nutraceutical compound that is abundant in the "Mediterranean diet", has been shown to be a potential therapeutic agent in cardiac and metabolic diseases. Here, we investigated the beneficial role of QUE and its derivative Q2, which demonstrates improved bioavailability and chemical stability, in cardiac lipotoxicity. To this end, H9c2 cardiomyocytes were pre-treated with QUE or Q2 and then exposed to palmitate (PA) to recapitulate the cardiac lipotoxicity occurring in obesity. Our results showed that both QUE and Q2 significantly attenuated PA-dependent cell death, although QUE was effective at a lower concentration (50 nM) when compared with Q2 (250 nM). QUE decreased the release of lactate dehydrogenase (LDH), an important indicator of cytotoxicity, and the accumulation of intracellular lipid droplets triggered by PA. On the other hand, QUE protected cardiomyocytes from PA-induced oxidative stress by counteracting the formation of malondialdehyde (MDA) and protein carbonyl groups (which are indicators of lipid peroxidation and protein oxidation, respectively) and intracellular ROS generation, and by improving the enzymatic activities of catalase and superoxide dismutase (SOD). Pre-treatment with QUE also significantly attenuated the inflammatory response induced by PA by reducing the release of key proinflammatory cytokines (IL-1β and TNF-α). Similar to QUE, Q2 (250 nM) also significantly counteracted the PA-provoked increase in intracellular lipid droplets, LDH, and MDA, improving SOD activity and decreasing the release of IL-1β and TNF-α. These results suggest that QUE and Q2 could be considered potential therapeutics for the treatment of the cardiac lipotoxicity that occurs in obesity and metabolic diseases.

Thymoquinone and quercetin protect against hepatic steatosis in association with SIRT1/AMPK stimulation and regulation of autophagy, perilipin-2, and cytosolic lipases

BACKGROUND

We sought to investigate thymoquinone (TQ)/quercetin combination in preventing hepatic steatosis (HS).

MATERIALS AND METHODS

The included rat groups; (1) Control, (2) HS model, (3) HS treated with TQ 10 mg.kg^-1.d^-1, (4) HS treated with quercetin 50 mg.kg^-1.d^-1, and (5) HS treated with both compounds for 4 weeks.

RESULTS

TQ/quercetin co-treatment augmented the anti-steatosis potential of each ingredient. The results revealed more (p < 0.001) sirtuin (SIRT1)/AMP-activated protein kinase (p-AMPK) upregulation compared to each treatment in line with autophagy protein Atg7 enhancement, and suppressed pro-inflammatory and oxidation markers. They diminished the hepatic lipogenic enzymes and perilipin-2 and activated the cytosolic lipases adipose triglyceride lipase (ATGL). Histological and Biochemical analysis revealed diminished lipid deposition and improved liver enzymes (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]) compared to the data of separate treatments.

CONCLUSION

TQ and quercitin effectively upregulated SIRT1/p-AMPK and regulated hepatic perilipin-2/ATGL, inflammation and oxidative stress, preserved liver structure and function. TQ/quercetin combination additively prevents HS.

Bioactive compounds in childhood obesity and associated metabolic complications: Current evidence, controversies and perspectives

Obesity represents the most frequent chronic disease among children worldwide, with a significant global burden on society. Metabolically unhealthy obesity (MUO) can affect children since their first years of life, and novel therapeutic strategies to tackle metabolic complications are under investigation. This review focuses on bioactive compounds and their possible beneficial effects on obesity, particularly omega-3, docosahexaenoic acid, vitamin D, biotics, polysaccharide macromolecules, polyphenols, inositols, alpha lipoic acid, and bromelaine. Our aim is to summarize current evidence about bioactive compounds in the treatment of obesity, highlighting recent findings on their use in children and adolescents. Most studied molecules are omega-3 and vitamin D, despite the heterogeneity between the studies. Moreover, given the emerging interest in the gut-brain axis in the link between metabolic health and microbiota, various studies on prebiotics, probiotics, synbiotics, postbiotics and polysaccharide macromolecules have been considered. Some preclinical studies seem to highlight a possible role of the polyphenols, even if their clinical evidence is still discussed. Lastly, we describe possible effects of inositols and alpha-lipoic acid. Despite some dietary supplements seem to be promising in overweight subjects, only in a few of them a dose/response efficacy has been found in the pediatric age. Innovative, well-designed and targeted clinical trials are then needed to prove the beneficial effects of these compounds that could support the standard behavioral therapy for obesity.

Integrated lipidomic and transcriptomic analyses reveal the mechanism of large yellow croaker roe phospholipids on lipid metabolism in normal-diet mice

Large yellow croaker roe phospholipids (LYCRPLs) could regulate the accumulation of triglycerides and blood lipid levels. However, there exists little research on the mechanism of LYCRPLs on lipid metabolism in normal-diet mice. In this work, the mice on a normal diet were given low-dose, medium-dose, and high-dose LYCRPLs by intragastric administration for 6 weeks. At the same time, the physiological and biochemical indicators of the mice were determined, and the histomorphological observation of the liver and epididymal fat was carried out. In addition, we examined the gene expression and lipid metabolites in the liver of mice using transcriptomic and lipidomic and performed a correlation analysis. The results showed that LYCRPLs regulated the lipid metabolism of normal-diet mice by affecting the expression of the glycerolipid metabolism pathway, insulin resistance pathway, and cholesterol metabolism pathway. This study not only elucidated the main pathway by which LYCRPLs regulate lipid metabolism, but also laid a foundation for exploring LYCRPLs as functional food supplements.

Bioactive dietary components-Anti-obesity effects related to energy metabolism and inflammation

Obesity is the result of the long-term energy imbalance between the excess calories consumed and the few calories expended. Reducing the intake of energy dense foods (fats, sugars), and strategies such as fasting and caloric restriction can promote body weight loss. Not only energy in terms of calories, but also the specific composition of the diet can affect the way the food is absorbed and how its energy is stored, used or dissipated. Recent research has shown that bioactive components of food, such as polyphenols and vitamins, can influence obesity and its pathologic complications such as insulin resistance, inflammation and metabolic syndrome. Individual micronutrients can influence lipid turnover but for long-term effects on weight stability, dietary patterns containing several micronutrients may be required. At the molecular level, these molecules modulate signaling and the expression of genes that are involved in the regulation of energy intake, lipid metabolism, adipogenesis into white, beige and brown adipose tissue, thermogenesis, lipotoxicity, adipo/cytokine synthesis, and inflammation. Higher concentrations of these molecules can be reached in the intestine, where they can modulate the composition and action of the microbiome. In this review, the molecular mechanisms by which bioactive compounds and vitamins modulate energy metabolism, inflammation and obesity are discussed.

Ameliorative Effect of Quercetin against Abamectin-Induced Hemato-Biochemical Alterations and Hepatorenal Oxidative Damage in Nile Tilapia, Oreochromis niloticus

Abamectin (ABM) is a common agricultural pesticide and veterinary anthelmintic drug. It can discharge from the sites of application to aquatic systems via surface run-off or spray drift, causing harmful effects to aquatic organisms. The present study investigated the protective effect of dietary quercetin supplementation on hemato-biochemical parameters and hepato-renal oxidative stress biomarkers in Nile tilapia (Oreochromis niloticus) exposed to a sublethal dose of ABM. Fish were allocated into six equal groups. The first group was kept as a control group. The second and third groups (Q₄₀₀, and Q₈₀₀) were fed diets supplemented with two quercetin levels (400 and 800 mg/kg diet), respectively. The fourth group (ABM) was intoxicated with 20.73 µg/L of ABM. The fifth and sixth groups (ABM + Q₄₀₀, and ABM + Q₈₀₀) were fed diet supplemented with two quercetin levels (400 and 800 mg/kg diet) and simultaneously intoxicated with ABM for 60 days. The results showed that ABM significantly decreased RBCs, hemoglobin content, hematocrit, total protein, albumin levels, and acetylcholinesterase activity activities compared to the control. Meanwhile, ABM significantly increased white blood cells, glucose, total lipids, cholesterol, and alanine and aspartate aminotransferase activities. Liver and kidney levels of lipid peroxidation was significantly increased, while hepato-renal antioxidant biomarkers (reduced glutathione, super oxide dismutase, catalase, and total antioxidant capacity) were significantly decreased upon ABM exposure. On the other hand, quercetin dietary supplementation improved the hemato-biochemical alterations and alleviated oxidative stress induced by ABM exposure. Fish supplemented with quercetin at a level of 800 mg/kg diet showed better alleviating effects against ABM compared to 400 mg/kg diet. Based on these study findings, we suggest that quercetin dietary supplementation (800 mg/kg) offered direct protection against ABM-induced physiological disturbance and oxidative stress in Nile tilapia.

Quercetin improves high-fat diet-induced obesity by modulating gut microbiota and metabolites in C57BL/6J mice

High-fat diet-induced obesity is characterized by low-grade inflammation, which has been linked to gut microbiota dysbiosis. We hypothesized that quercetin supplementation would alter gut microbiota and reduce inflammation in obese mice. Male C57BL/6J mice, 4 weeks of age, were divided into 3 groups, including a low-fat diet group, a high-fat diet (HFD) group, and a high-fat diet plus quercetin (HFD+Q) group. The mice in HFD+Q group were given 50 mg per kg BW quercetin by gavage for 20 weeks. The body weight, fat accumulation, gut barrier function, glucose tolerance, and adipose tissue inflammation were determined in mice. 16 s rRNA amplicon sequence and non-targeted metabolomics analysis were used to explore the alteration of gut microbiota and metabolites. We found that quercetin significantly alleviated HFD-induced obesity, improved glucose tolerance, recovered gut barrier function, and reduced adipose tissue inflammation. Moreover, quercetin ameliorated HFD-induced gut microbiota disorder by regulating the abundance of gut microbiota, such as Adlercreutzia, Allobaculum, Coprococcus_1, Lactococcus, and Akkermansia. Quercetin influenced the production of metabolites that were linked to alterations in obesity-related inflammation and oxidative stress, such as Glycerophospho-N-palmitoyl ethanolamine, sanguisorbic acid dilactone, O-Phospho-L-serine, and P-benzoquinone. Our results demonstrate that the anti-obesity effects of quercetin may be mediated through regulation in gut microbiota and metabolites.

Obese mammary tumour-bearing mice are highly sensitive to doxorubicin-induced hepatotoxicity

BACKGROUND

Breast cancer is a major health burden for women, worldwide. Lifestyle-related risk factors, such as obesity and being overweight, have reached epidemic proportions and contributes to the development of breast cancer. Doxorubicin (DXR) is a chemotherapeutic drug commonly used to treat breast cancer, and although effective, may cause toxicity to other organs. The mechanisms and effects of DXR on hepatic tissue, and the contributing role of obesity, in breast cancer patients are poorly understood. The aim of this study was therefore to investigate the effects of DXR on hepatic tissue in an obese tumour-bearing mouse model.

METHODS

A diet-induced obesity (DIO) mouse model was established, where seventy-four three-week-old female C57BL6 mice were divided into two main groups, namely the high fat diet (containing 60% kcal fat) and standard diet (containing 10% kcal fat) groups. After eight weeks on their respective diets, the DIO phenotype was established, and the mice were further divided into tumour and non-tumour groups. Mice were subcutaneously inoculated with E0771 triple negative breast cancer cells in the fourth mammary gland and received three doses of 4 mg/kg DXR (cumulative dosage of 12 mg/kg) or vehicle treatments via intraperitoneal injection. The expression levels of markers involved in apoptosis and alanine aminotransferase (ALT) were compared by means of western blotting. To assess the pathology and morphology of hepatic tissue, haematoxylin and eosin staining was performed. The presence of fibrosis and lipid accumulation in hepatic tissues were assessed with Masson's trichrome and Oil Red O staining, respectively.

RESULTS

Microscopic examination of liver tissues showed significant changes in the high fat diet tumour-bearing mice treated with DXR, consisting of macrovesicular steatosis, hepatocyte ballooning and lobular inflammation, compared to the standard diet tumour-bearing mice treated with DXR and the control group (standard diet mice). These changes are the hallmarks of non-alcoholic fatty liver disease, associated with obesity.

CONCLUSION

The histopathological findings indicated that DXR caused significant hepatic parenchymal injury in the obese tumour-bearing mice. Hepatotoxicity is aggravated in obesity as an underlying co-morbidity. It has been shown that obesity is associated with poor clinical outcomes in patients receiving neo-adjuvant chemotherapy treatment regimens.

Role of potential bioactive metabolites from traditional Chinese medicine for type 2 diabetes mellitus: An overview

Type 2 diabetes mellitus (T2DM) is a metabolic disease with persistent hyperglycemia primarily caused by insulin resistance (IR). The number of diabetic patients globally has been rising over the past decades. Although significant progress has been made in treating diabetes mellitus (DM), existing clinical drugs for diabetes can no longer fully meet patients when they face complex and huge clinical treatment needs. As a traditional and effective medical system, traditional Chinese medicine (TCM) has a unique understanding of diabetes treatment and has developed many classic and practical prescriptions targeting DM. With modern medicine and pharmacy advancements, researchers have discovered that various bioactive metabolites isolated from TCM show therapeutic on DM. Compared with existing clinical drugs, these bioactive metabolites demonstrate promising prospects for treating DM due to their excellent biocompatibility and fewer adverse reactions. Accordingly, these valuable metabolites have attracted the interest of researchers worldwide. Despite the abundance of research works and specialized-topic reviews published over the past years, there is a lack of updated and systematic reviews concerning this fast-growing field. Therefore, in this review, we summarized the bioactive metabolites derived from TCM with the potential treatment of T2DM by searching several authoritative databases such as PubMed, Web of Science, Wiley Online Library, and Springer Link. For the convenience of readers, the content is divided into four parts according to the structural characteristics of these valuable compounds (flavonoids, terpenoids, alkaloids, and others). Meanwhile, the detailed mechanism and future directions of these promising compounds curing DM are also summarized in the related sections. We hope this review inspires increasingly valuable and significant research focusing on potential bioactive metabolites from TCM to treat DM in the future.

Effect of natural polyphenols in Chinese herbal medicine on obesity and diabetes: Interactions among gut microbiota, metabolism, and immunity

With global prevalence, metabolic diseases, represented by obesity and type 2 diabetes mellitus (T2DM), have a huge burden on human health and medical expenses. It is estimated that obese population has doubled in recent 40 years, and population with diabetes will increase 1.5 times in next 25 years, which has inspired the pursuit of economical and effective prevention and treatment methods. Natural polyphenols are emerging as a class of natural bioactive compounds with potential beneficial effects on the alleviation of obesity and T2DM. In this review, we investigated the network interaction mechanism of "gut microbial disturbance, metabolic disorder, and immune imbalance" in both obesity and T2DM and systemically summarized their multiple targets in the treatment of obesity and T2DM, including enrichment of the beneficial gut microbiota (genera Bifidobacterium, Akkermansia, and Lactobacillus) and upregulation of the levels of gut microbiota-derived metabolites [short-chain fatty acids (SCFAs)] and bile acids (BAs). Moreover, we explored their effect on host glucolipid metabolism, the AMPK pathway, and immune modulation via the inhibition of pro-inflammatory immune cells (M1-like Mϕs, Th1, and Th17 cells); proliferation, recruitment, differentiation, and function; and related cytokines (TNF-α, IL-1β, IL-6, IL-17, and MCP-1). We hope to provide evidence to promote the clinical application of natural polyphenols in the management of obesity and T2DM.

Effects of Quercetin on the Intestinal Microflora of Freshwater Dark Sleeper Odontobutis potamophila

Flavonoids have antimicrobial and anti-oxidation properties. The effects of the flavonoid quercetin on the intestinal microflora of freshwater dark sleeper Odontobutis potamophila were tested for the first time. Odontobutis potamophila juveniles were treated with quercetin for 21 days at one of three concentrations (2.5, 5.0, or 10.0 mg/L) and compared with a control group that was not treated with quercetin. Quercetin improved the stability of the intestinal flora in O. potamophila and the probiotic bacteria Bacillus spp. and Lactobacillus spp. increased in species abundance after the low concentration quercetin treatments. Furthermore, the abundance of pathogenic bacteria Plesiomonas spp., Aeromonas spp., and Shewanella spp. decreased after the fish had been exposed to quercetin. Activity of hepatic antioxidant enzymes (superoxide dismutase, SOD), (glutathione S-transferase, GST), (glutathione peroxidase, GSH-Px), and (total antioxidant capacity, T-AOC) increased in the livers of O. potamophila treated with quercetin, thereby increasing their hepatic antioxidant capacity and their ability to scavenge free radicals.

Effects of Dried Onion Powder and Quercetin on Obesity-Associated Hepatic Menifestation and Retinopathy

Onion (Allium cepa L.), rich in flavonoids (particularly quercetin), reportedly has anti-obesity properties, but the underlying mechanisms and associated health issues remain unclear. In this study, we compared the effects of dried onion powder (DO) with that of quercetin on high-fat diet (HFD)-induced obesity, nonalcoholic fatty liver disease, and retinal neovascularization. Briefly, rats (n = 9–10 per group) were divided into control, HFD alone (43% fat), HFD + DO (1% DO), HFD + 5DO (5% DO, w/w), and HFD + quercetin (180 mg/kg). After 12 weeks, body fat, markers of metabolism, fatty liver, steatohepatitis, and retinopathy were analyzed. The results revealed that DO and 5DO dose-dependently suppressed body weight, visceral and subcutaneous fat accumulation, and epididymal adipocyte in HFD-fed rats. DO also decreased HFD-induced ALT, AST, free fatty acid, glucose, proinflammatory cytokines, and oxidative stress. DO and 5DO groups had lower triglycerides, total cholesterol, proinflammatory cytokine levels, and ACC-α (a fatty acid synthesis–associated enzyme) expression but higher hepatic antioxidant enzyme activities and fecal lipids. 5DO exhibited better or similar efficacy to quercetin. Both 5DO and quercetin increased fecal levels of acetic acid and butyric acid similarly. They also reduced lipid peroxidation of the eye, retinal adiposity, and neovascularization. However, quercetin resulted in a more apparent decrease in regulation of the Raf/MAPK pathway than DO in eye specimens. Conclusively, DO suppresses visceral, subcutaneous, and liver fat accumulation better than quercetin likely due to higher fecal fat excretion and lower oxidative stress, proinflammatory cytokine levels, and ACC-α expression. Quercetin regulating signal pathways is better than DO at reducing retinal adiposity and neovascularization.

Effect of sodium hexametaphosphate and quercetin, associated or not with fluoride, on dentin erosion in vitro

OBJECTIVE

to investigate the ability of solutions containing sodium hexametaphosphate, fluoride and quercetin, alone or in association, to prevent dentin erosion and to inhibit matrix metalloproteinases -2 and -9 activity using in vitro protocols.

DESIGN

Root dentin blocks (n = 96) were prepared and divided into 8 experimental groups (n = 12/group), according to the solutions to be tested: Placebo; 0.24% sodium fluoride (F); 1.0% sodium hexametaphosphate (HMP); 0.03% quercetin (QC); F+HMP; F+QC; HMP+QC; and F+HMP+QC. Erosive challenges were performed 4×/day for 5 days. Specimens were treated with the respective solutions for one minute, twice a day. Next, dentin loss (profilometry) and integrated hardness area in depth (KHN × µm) were determined. The antiproteolytic potential was assessed by gelatin zymography. Dentin erosion results (log₁₀-transformed) were submitted to one-way ANOVA, followed by Tukey's test. Integrated hardness area in depth data (raw) were submitted to two-way, repeated-measures ANOVA, followed by Holm-Sidak's test (p<0.05).

RESULTS

Dentin erosion was significantly lower for F+HMP+QC than for all other treatments. At the shallowest depths (5-30 µm), blocks treated with F+HMP+QC had the highest integrated hardness area in depth values. All treatments completely inhibited matrix metalloproteinases-2 activity, except for the group QC (77% inhibition). For matrix metalloproteinases-9, all HMP-containing solutions or F+QC promoted total antiproteolytic activity.

CONCLUSION

The association of fluoride, sodium hexametaphosphate, and quercetin must be considered a valuable strategy for novel product formulation for home and professional use, considering its superior protective effects against dentin erosion and its antiproteolytic potential.

Potential Pharmaceutical Applications of Quercetin in Cardiovascular Diseases

Quercetin, as a member of flavonoids, has emerged as a potential therapeutic agent in cardiovascular diseases (CVDs) in recent decades. In this comprehensive literature review, our goal was a critical appraisal of the pathophysiological mechanisms of quercetin in relation to the classical cardiovascular risk factors (e.g., hyperlipidemia), atherosclerosis, etc. We also assessed experimental and clinical data about its potential application in CVDs. Experimental studies including both in vitro methods and in vivo animal models mainly outline the following effects of quercetin: (1) antihypertensive, (2) hypolipidemic, (3) hypoglycemic, (4) anti-atherosclerotic, and (5) cardioprotective (suppressed cardiotoxicity). From the clinical point of view, there are human studies and meta-analyses implicating its beneficial effects on glycemic and lipid parameters. In contrast, other human studies failed to demonstrate consistent favorable effects of quercetin on other cardiometabolic risk factors such as MS, obesity, and hypertension, underlying the need for further investigation. Analyzing the reason of this inconsistency, we identified significant drawbacks in the clinical trials’ design, while the absence of pharmacokinetic/pharmacodynamic tests prior to the studies attenuated the power of clinical results. Therefore, additional well-designed preclinical and clinical studies are required to examine the therapeutic mechanisms and clinical efficacy of quercetin in CVDs.

Research Advances in Lotus Leaf as Chinese Dietary Herbal Medicine

Lotus leaf (Heye), the dry foliage of Nelumbo nucifera Gaertn, has been valuable as a dietary herbal medicine for thousands of years. Phytochemical studies indicated that alkaloids and flavonoids are the main components of Heye. Polysaccharides, terpenes, and amino acids are also active ingredients. The drug properties of Heye are mild and bitter. Meridian tropism is mainly distributed in the liver, spleen, and stomach meridian. In the Traditional Chinese medicine (TCM) theoretical system, it is in many formulas for the therapy of various symptoms, including wasting-thirst induced by summer heat, diarrhea caused by summer heat-dampness and spleen deficiency, hematochezia, flooding and spotting, among others. Nowadays, the extracts and active components of Heye demonstrate multiple bioactivities, for instance anti-obesity, anti-inflammatory, anti-oxidant, cardiovascular protective, anticancer, hepatoprotective, hypoglycemic, antiviral, antimicrobial, as well as hemostatic activities. This review will provide an overview of Heye serving as a typical plant with functions of both medicine and food, including its practical applications in terms of TCM and healthy diet, phytochemistry, pharmacological activity, together with its toxicity. Besides, the new points and prospects of Heye in the overview are also outlined straightforwardly.

Large Yellow Tea Extract Ameliorates Metabolic Syndrome by Suppressing Lipogenesis through SIRT6/SREBP1 Pathway and Modulating Microbiota in Leptin Receptor Knockout Rats

Metabolic syndrome is a chronic metabolic disorder that has turned into a severe health problem worldwide. A previous study reported that large yellow tea exhibited better anti-diabetic and lipid-lowering effects than green tea. Nevertheless, the potential mechanisms are not yet understood. In this study, we examined the prevention effects and mechanisms of large yellow tea water extract (LWE) on metabolic syndrome using leptin receptor knockout (Lepr−/−) rats. Seven-week-old male Lepr−/− and wild type (WT) littermate rats were divided into Lepr−/− control group (KO) (n = 5), Lepr−/− with LWE-treated group (KL) (n = 5), WT control group (WT) (n = 6), and WT with LWE intervention group (WL) (n = 6). Then, the rats were administered water or LWE (700 mg/kg BW) daily by oral gavage for 24 weeks, respectively. The results showed that the administration of LWE significantly reduced the serum concentrations of random blood glucose, total cholesterol, triglyceride, and free fatty acids, and increased glucose tolerance in Lepr−/− rats. Moreover, LWE remarkably reduced hepatic lipid accumulation and alleviated fatty liver formation in Lepr−/− rats. A mechanistic study showed that LWE obviously activated SIRT6 and decreased the expression of key lipogenesis-related molecules SREBP1, FAS, and DGAT1 in the livers of Lepr−/− rats. Furthermore, LWE significantly improved microbiota dysbiosis via an increase in gut microbiota diversity and an abundance of the microbiota that produce short chain fatty acids (SCFAs), such as Ruminococcaceae, Faecalibaculum, Intestinimonas, and Alistipes. Finally, LWE supplementation increased the concentrations of SCFAs in the feces of Lepr−/− rats. These results revealed that LWE attenuated metabolic syndrome of Lepr−/− rats via the reduction of hepatic lipid synthesis through the SIRT6/SREBP1 pathway and the modulation of gut microbiota.

A critical evaluation of risk to reward ratio of quercetin supplementation for COVID-19 and associated comorbid conditions

The interim results of the large, multinational trials on coronavirus disease 2019 (COVID‐19) using a combination of antiviral drugs appear to have little to no effect on the 28‐day mortality or the in‐hospital course. Therefore, there is a still vivid interest in finding alternate re‐purposed drugs and nutrition supplements, which can halt or slow the disease severity. We review here the multiple preclinical studies, partially supported by clinical evidence showing the quercetin's possible therapeutic/prophylaxis efficacy against severe acute respiratory syndrome coronavirus (SARS‐CoV) as well as comorbidities like chronic obstructive pulmonary disease (COPD), diabetes mellitus, obesity, coagulopathy, and hypertension. Currently, 14 interventional clinical trials are underway assessing the efficacy of quercetin along with other antiviral drugs/nutritional supplements as prophylaxis/treatment option against COVID‐19. The present review is tempting to suggest that, based on circumstantial scientific evidence and preliminary clinical data, the flavonoid quercetin can ameliorate COVID‐19 infection and symptoms acting in concert on two parallel and independent paths: inhibiting key factors responsible for SARS‐CoV‐2 infections and mitigating the clinical manifestations of the disease in patients with comorbid conditions. Despite the broad therapeutic properties of quercetin, further high power randomized clinical trials are needed to firmly establish its clinical efficacy against COVID‐19.

Quercetin Regulates Calcium and Phosphorus Metabolism Through the Wnt Signaling Pathway in Broilers

This study intended to explore the effect and mechanism of different doses of dietary quercetin on calcium and phosphorus metabolism to provide an experimental basis for preventing leg disease in broilers. A total of 480 1-day-old healthy Arbor Acre broilers were randomly allotted into four groups (0, 0.02, 0.04, 0.06%) for 42 days. Compared with control, 0.06% quercetin significantly increased the unit weight and the relative weight of tibia in broilers (P < 0.05). Meanwhile, phosphorus content and bone mineral density (BMD) were significantly increased by 0.06% dietary quercetin supplementation in tibia (P < 0.05). Ash of tibia was significantly increased by 0.04 and 0.06% quercetin in broilers (P < 0.05). In addition, 0.06% quercetin significantly increased the content of serum calcium-binding protein (CB), estradiol (E₂), osteocalcin (OC), alkaline phosphatase (ALP), and calcitonin (CT) (P < 0.05); 0.04% quercetin significantly increased 1,25-dihydroxyvitamin D₃ (1,25-(OH)₂D₃) (P < 0.05) content in serum of broilers. The content of serum parathyroid (PTH) was significantly decreased by 0.02 and 0.06% quercetin (P < 0.05) in broilers. Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the Wnt signaling pathway was a key signaling pathway of calcium and phosphorus metabolism in broilers which was significantly regulated by quercetin. The differentially expressed genes (DEGs) from transcriptome sequencing were validated with real-time quantitative PCR (RT-qPCR). In conclusion, 0.06% dietary quercetin supplementation improved calcium and phosphorus metabolism by regulating the Wnt signaling pathway in broilers.

A comprehensive review on phytochemicals for fatty liver: are they potential adjuvants?

Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome and, as such, is associated with obesity. With the current and growing epidemic of obesity, NAFLD is already considered the most common liver disease in the world. Currently, there is no official treatment for the disease besides weight loss. Although there are a few synthetic drugs currently being studied, there is also an abundance of herbal products that could also be used for treatment. With the World Health Organization (WHO) traditional medicine strategy (2014-2023) in mind, this review aims to analyze the mechanisms of action of some of these herbal products, as well as evaluate toxicity and herb-drug interactions available in literature.

Quercetin extracted from Sophora japonica flower improves growth performance, nutrient digestibility, cecal microbiota, organ indexes, and breast quality in broiler chicks

Objective

The objective of this study was to evaluate the effects of supplementing quercetin extracted from Sophora japonica flower (QS) to the diet of broiler chicks on their growth performance, apparent nutrient digestibility, cecal microbiota, serum lipid profiles, relative organ weight, and breast muscle quality.

Method

A total of 1088 1-day-old broiler chicks (mixed sex) were randomly assigned to four groups based on the initial body weight (43.00 ± 0.29 g). The experimental period was 35 days (starter, days 0-7; grower, days 7-21; finisher, days 21-35). There were 17 replicate cages per treatment and 16 birds per cage. Dietary treatments consisted of birds receiving basal diet without quercetin as the control group and treatment groups consisted of birds fed basal diet supplemented with 0.2, 0.4, or 0.6 g/kg QS.

Results

With the increase of the QS dosage, body weight gain during days 0-7 (P = 0.021), 7-21 (P = 0.010), and 1-35 (P = 0.045), feed intake during days 0-7 (P = 0.037) and 1-35 (P = 0.025), apparent dry matter digestibility (P = 0.008), apparent energy retention (P = 0.004), cecal lactic acid bacteria counts (P = 0.023), the relative weight of breast muscle (P = 0.014), pH value from breast muscle (P < 0.001), and the water holding capacity of breast muscle (P = 0.012) increased linearly, whereas the drip loss from breast muscle (P = 0.001) decreased linearly.

Conclusion

The addition of QS in the diet of broiler chicks had positive effects on the breast muscle yield and breast muscle quality, and improved the dry matter digestibility and energy retention by increasing cecal beneficial bacteria counts, thus improving growth performance.

Nonalcoholic fatty liver disease: The role of quercetin and its therapeutic implications

Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease, affecting almost one-third of the general population and 75% of obese patients with type 2 diabetes. The aim of this article is to review the current evidence concerning the role of quercetin, a natural compound and flavonoid, and its possible therapeutic effects on this modern-day disease. Despite the fact that the exact pathophysiological mechanisms through which quercetin has a hepatoprotective effect on NAFLD are still not fully elucidated, this review clearly demonstrates that this flavonoid has potent antioxidative stress action and inhibitory effects on hepatocyte apoptosis, inflammation, and generation of reactive oxygen species, factors which are linked to the development of the disease. NAFLD is closely associated with increased dietary fat consumption, especially in Western countries. The hepatoprotective effect of quercetin against NAFLD merits serious consideration and further validation by future studies.

Tomato (Solanum lycopersicum L.) seed: A review on bioactives and biomedical activities

The processing of tomato fruit into puree, juices, ketchup, sauces, and dried powders generates a significant amount of waste in the form of tomato pomace, which includes seeds and skin. Tomato processing by-products, particularly seeds, are reservoirs of health-promoting macromolecules, such as proteins (bioactive peptides), carotenoids (lycopene), polysaccharides (pectin), phytochemicals (flavonoids), and vitamins (α-tocopherol). Health-promoting properties make these bioactive components suitable candidates for the development of novel food and nutraceutical products. This review comprehensively demonstrates the bioactive compounds of tomato seeds along with diverse biomedical activities of tomato seed extract (TSE) for treating cardiovascular ailments, neurological disorders, and act as antioxidant, anticancer, and antimicrobial agent. Utilization of bioactive components can improve the economic feasibility of the tomato processing industry and may help to reduce the environmental pollution generated by tomato by-products.

Adipogenesis and therapeutic potentials of antiobesogenic phytochemicals: Insights from preclinical studies

Obesity is one of the most serious public health problems in both developed and developing countries in recent years. While lifestyle and diet modifications are the most important management strategies of obesity, these may be insufficient to ensure long-term weight reduction in certain individuals and alternative strategies including pharmacotherapy need to be considered. However, drugs option remains limited due to low efficacy and adverse effects associated with their use. Hence, identification of safe and effective alternative therapeutic agents remains warranted to combat obesity. In recent years, bioactive phytochemicals are considered as valuable sources for the discovery of new pharmacological agents for the treatment of obesity. Adipocyte hypertrophy and hyperplasia increases with obesity and undergo molecular and cellular alterations that can affect systemic metabolism giving rise to metabolic syndrome and comorbidities such as type 2 diabetes and cardiovascular diseases. Many phytochemicals have been reported to target adipocytes by inhibiting adipogenesis, inducing lipolysis, suppressing the differentiation of preadipocytes to mature adipocytes, reducing energy intake, and boosting energy expenditure mainly in vitro and in animal studies. Nevertheless, further high-quality studies are needed to firmly establish the clinical efficacy of these phytochemicals. This review outlines common pathways involved in adipogenesis and phytochemicals targeting effector molecules of these pathways, the challenges faced and the way forward for the development of phytochemicals as antiobesity agents.

The Therapeutic Effects and Mechanisms of Quercetin on Metabolic Diseases: Pharmacological Data and Clinical Evidence

Metabolic diseases have become major public health issues worldwide. Searching for effective drugs for treating metabolic diseases from natural compounds has attracted increasing attention. Quercetin, an important natural flavonoid, is extensively present in fruits, vegetables, and medicinal plants. Due to its potentially beneficial effects on human health, quercetin has become the focus of medicinal attention. In this review, we provide a timely and comprehensive summary of the pharmacological advances and clinical data of quercetin in the treatment of three metabolic diseases, including diabetes, hyperlipidemia, and nonalcoholic fatty liver disease (NAFLD). Accumulating evidences obtained from animal experiments prove that quercetin has beneficial effects on these three diseases. It can promote insulin secretion, improve insulin resistance, lower blood lipid levels, inhibit inflammation and oxidative stress, alleviate hepatic lipid accumulation, and regulate gut microbiota disorders in animal models. However, human clinical studies on the effects of quercetin in diabetes, hyperlipidemia, and NAFLD remain scarce. More clinical trials with larger sample sizes and longer trial durations are needed to verify its true effectiveness in human subjects. Moreover, another important issue that needs to be resolved in future research is to improve the bioavailability of quercetin. This review may provide valuable information for the basic research, drug development, and clinical application of quercetin in the treatment of metabolic diseases.

A review of the protective effects of quercetin-rich natural compounds for treating ischemia-reperfusion injury

Ischemia-reperfusion (IR) injury causes dysfunction of tissues and organs, and oxidative stress plays an important role. During IR, reactive oxygen species (ROS) are increased. Antioxidants are used to decrease ROS associated with IR. We review the protective effects of quercetin-rich natural antioxidants against IR. We searched PubMed, ScienceDirect, Scopus and Cochrane databases using the keywords: ischemic reperfusion, quercetin, antioxidant and herbal medicine. The effects of quercetin during IR have been reported for animal models in vitro and in vivo. Quercetin-rich plants including Abelmoschus esculentus, coriander, Hypericum perforatum, onion, Psidium guajava, buckwheat and Rosa laevigata Michx have been used to reduce oxidative stress damage to various organs during IR.

Quercetin and non-alcoholic fatty liver disease: A review based on experimental data and bioinformatic analysis

Quercetin, a polyphenol widely present in the plant kingdom, has received great interest due to pleiotropic effects. As evidenced by animal and cellular studies, quercetin exerts hepatoprotection against non-alcoholic fatty liver disease (NAFLD), particularly in hepatic steatosis and hepatitis. Mechanically, various hypotheses of such protective effects have been actively proposed, including improving fatty acid metabolism, anti-inflammation, anti-oxidant, modulating gut microbiota and bile acid, etc. Here, the role of quercetin in NAFLD was summarized. With a particular focus on molecular mechanism, we comprehensively discussed the pathways of quercetin on NAFLD based on the analysis from Gene Expression Omnibus (GEO) database and experimental evidence.

Dietary bioactive compounds as modulators of mitochondrial function

The increase in incidence and prevalence of metabolic diseases, such as diabetes, obesity, and metabolic syndrome, is a health problem worldwide. Nutritional strategies that can impact on mitochondrial activity represent a novel and effective option to modulate energy expenditure and energetic metabolism in cells and tissues and could be used as adjuvant treatments for metabolic-associated disorders. Dietary bioactive compounds also known as "food bioactives" have proven to exert multiple health benefits and counteract metabolic alterations. In the last years, it has been consistently reported that the modulation of mitochondrial function represents one of the mechanisms behind the bioactive compounds-dependent health improvements. In this review, we focus on gathering, summarizing, and discussing the evidence that supports the effect of dietary bioactive compounds on mitochondrial activity and the relation of these effects in the pathological context. Despite the evidence presented here on in vivo and in vitro effects, more studies are needed to determine their effectiveness in humans.

Postnatally induced metabolic and oxidative changes associated with maternal high-fat consumption were mildly affected by Quercetin-3-O-rutinoside treatment in rats

Oxidative stress is usually associated with prolonged intake of high-fat diet (HFD). However, little is known about the impact of maternal HFD on endogenous modulation of antioxidant-defence-enzyme-network, its link to adverse fetal growth and overall effects of Quercetin-3-o-rutinoside (QR) supplementation. Sprague-Dawley rats were initially assigned to normal diet (ND) or HFD for 8 weeks and mated. Post-conception, rats were further divided into four groups, of which two groups had diets supplemented with QR while others continued with their respective diets until delivery. Measurements include food and water consumption, physical parameters (body weight, body mass index (BMI) and fur appearance), oral glucose tolerance, lipid profiles, and placental/liver oxidative changes. We observed that water consumption was significantly increased in dams fed HFD without marked differences in food intake, body weight, BMI and glucose tolerance. Surprisingly, offspring of HFD-fed dams had reduced body weight marked by delayed fur appearance compared to the ND offspring. In dams, there were alterations in lipid profile. Lipid peroxidation was increased in the placenta and liver of gestational day (GD) 19 HFD-fed dams and their postnatal day (PND) 21 male offspring. There was evidence of HFD-induced nitrosative stress in dams and PND28 female offspring. Adaptive defence indicate decreased placenta and liver superoxide dismutase (SOD) levels as well as differential changes in total antioxidant capacity (TAC) and catalase (CAT) activity in HFD treated dams and their progenies. Overall, the results indicate that intrauterine metabolic alterations associated with maternal high-fat consumption may induce oxidative challenge in the offspring accompanied by mild developmental consequences, while QR supplementation has little or no beneficial effects.

New insight into the role of isorhamnetin as a regulator of insulin signaling pathway in type 2 diabetes mellitus rat model: Molecular and computational approach

We intended to examine the molecular mechanism of action of isorhamnetin (IHN) to regulate the pathway of insulin signaling. Molecular analysis, immunofluorescence, and histopathological examination were used to assess the anti-hyperglycemic and insulin resistance lowering effects of IHN in streptozotocin /high fat diet-induced type 2 diabetes using Wistar rats. At the microscopic level, treatment with IHN resulted in the restoration of myofibrils uniform arrangement and adipose tissue normal architecture. At the molecular level, treatment with IHN at three different doses showed a significant decrease in m-TOR, IGF1-R & LncRNA-RP11-773H22.4. expression and it up-regulated the expression of AKT2 mRNA, miR-1, and miR-3163 in both skeletal muscle and adipose tissue. At the protein level, IHN treated group showed a discrete spread with a moderate faint expression of m-TOR in skeletal muscles as well as adipose tissues. We concluded that IHN could be used in the in ameliorating insulin resistance associated with type 2 diabetes mellitus.

Metabolomics Analyses of Cotyledon and Plumule Showing the Potential Domestic Selection in Lotus Breeding

Lotus (Nelumbo nucifera) seeds are widely consumed as functional food or herbal medicine, of which cotyledon (CL) is the main edible part, and lotus plumule (LP) is commonly utilized in traditional Chinese medicine. However, few studies have been conducted to investigate the chemical components of CL and LP in dry lotus seeds, not to mention the comparison between wild and domesticated varieties. In this study, a widely targeted metabolomics approach based on Ultra Performance Liquid Chromatography-electrospray ionization-Tandem mass spectrometry (UPLC-ESI-MS/MS) was utilized to analyze the metabolites in CL and LP of China Antique (“CA”, a wild variety) and Jianxuan-17 (“JX”, a popular cultivar). A total of 402 metabolites were identified, which included flavonoids (23.08% to 27.84%), amino acids and derivatives (14.18–16.57%), phenolic acids (11.49–12.63%), and lipids (9.14–10.95%). These metabolites were classified into ten clusters based on their organ or cultivar-specific characters. Most of these metabolites were more abundant in LP than in CL for both varieties, except for metabolites belonging to organic acids and lipids. The analysis of differentially accumulated metabolites (DAMs) demonstrated that more than 25% of metabolites detected in our study were DAMs in CL and LP comparing “JX” with “CA”, most of which were less abundant in “JX”, including 35 flavonoids in LP, 23 amino acids and derivatives in CL, 7 alkaloids in CL, and 10 nucleotides and derivatives in LP, whereas all of 11 differentially accumulated lipids in LP were more abundant in “JX”. Together with the fact that the seed yield of “JX” is much higher than that of “CA”, these results indicated that abundant metabolites, especially the functional secondary metabolites (mainly flavonoids and alkaloids), were lost during the process of breeding selection.

Effects of polymorphism of the GPAM gene on milk quality traits and its relation to triglyceride metabolism in bovine mammary epithelial cells of dairy cattle

Mitochondrial glycerol-3-phosphate acyltransferase (GPAM) catalyses the initial and rate-regulated first-stage pathway of glycerol lipid synthesis and helps to allocate acyl-CoA (acyl-coenzyme A) to triglyceride (TG) synthesis and away from degradation pathways in animal lipometabolism-related pathways. In this study, RNA interference (RNAi) and GPAM gene overexpression were used to examine the correlation between the expression of GPAM and adipogenesis in bovine mammary epithelial cells (bMECs). Additionally, three novel polymorphisms were identified within the bovine key functional domain of GPAM with Sanger sequencing. The relationship between variants of the GPAM gene and milk quality traits of Chinese Holstein cows was then analysed using statistical methods. The results showed that knockdown of the GPAM gene significantly reduced the synthesis of triglycerides in the bMECs (p < 0.05), whereas the overexpression of the GPAM gene significantly increased the synthesis of TG (p < 0.05). In Chinese Holstein dairy cattle, the polymorphic locus of the GPAM gene E20-3386G > A was significantly correlated with fat, protein and somatic cell count (p < 0.05); I18-652A > G was significantly correlated with fat, total fat content, protein, dry matter and somatic cell count (p < 0.05); and I18-726A > G was significantly correlated with protein, milk yield, dry matter and somatic cell count (p < 0.05). Specifically, individuals with the AA genotype of the I18-652A > G and E20-3386G > A polymorphic loci had a higher milk fat percentage (p < 0.05). In summary, GPAM plays a pivotal role in the intracellular regulation of triglyceride, and its mutations could work as a competent molecular marker for selective breeding in dairy cattle.