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Quercetin is a polyphenolic flavonoid. Common sources in the diet are apples, onions, berries, and red wine. Epidemiological studies have found an inverse relationship between dietary quercetin intake and cardiovascular disease. This has led to in vitro, in vivo, and clinical research to determine the mechanism by which quercetin exerts cardioprote...
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... chemical structure of pure quercetin is an unconjugated aglycone that does not have a carbohydrate moiety (Fig. 1). Quercetin in foods, such as onions, has a sugar group in its structure, which is known as a glycoside form (Fig. 2). Sup- plemental forms of quercetin are usually quercetin aglycone, although some products have small amounts of a glycoside called rutin as well. The bioavailability of quercetin is depen- dent on the form of quercetin ...
Context 2
... role of quercetin to decrease blood pressure in animals and humans Please note that all studies reviewed here used the aglycone form of quercetin ( Fig. 1) unless otherwise noted. Quercetin has been shown to have vasodilator effects in vitro using iso- lated rat arteries (42)(43)(44). This vasodilatory effect is also ob- served using metabolites of quercetin such as isorhamnetin, tamarixetin, and kaempferol and is reported to be independent of the endothelium (42,44). It should also be ...
Citations
... It has been observed that quercetin can trigger the breakdown of fat cells in a manner that depends on both the dosage and duration, by elevating levels of cyclic adenosine monophosphate and enhancing the activity of hormone-sensitive lipase (Ahn, Lee, Kim, Park, & Ha, 2008;Huang, Liao, Dong, & Pu, 2019). Moreover, some studies suggest that quercetin may have a modest hypotensive effect, possibly through its ability to improve blood vessel function and reduce inflammation (Dagher et al., 2021;Larson, Symons, & Jalili, 2010;Nazari-Khanamiri & Ghasemnejad-Berenji, 2023;Papakyriakopoulou et al., 2022). Quercetin also has been investigated for its potential to improve insulin sensitivity and regulate fasting blood glucose (FBG) levels (Ansari et al., 2022;Papakyriakopoulou et al., 2022). ...
... Los polifenoles inhiben la actividad enzimática compitiendo con el sustrato por los sitios activos. Además, los flavonoides están directamente relacionados con su capacidad para unirse con el ion zinc en el sitio activo de ECA (Larson, Symons & Jalili, 2010). Estos compuestos también mostraron competencia inhibición enzimática, en la que la presencia de grupos hidroxilo y el anillo B desempeña un papel importante en la actividad inhibidora (Balasuriya & Rupasinghe, 2012). ...
Fruits contain high levels of biologically active compounds that impart health benefits, Zacatecas occupies the first places in quince production nationwide. The objective of the present study was to evaluate the content and profile of phenolic compounds, as well as to the antioxidant and antihypertensive of quince harvested in Zacatecas. Methanolic extracts were made to evaluate the antioxidant capacity and it was determined by the DPPH and ABTS methods. The antihypertensive activity was evaluated by means of the inhibition of the angiotensin converting enzyme I, presenting an inhibition of 45%, and the phenolic compounds profile was determined by HPLC-DAD. The flavonoid and tannin content were 422 and 250 mg of catechin equivalents/ 100 g (db), respectively; for total phenolics it was 122 mg of gallic acid equivalents/ 100 g (db) and for coumarins 46 mg of coumarin equivalents/100 g (db). Regarding antioxidant capacity, levels of 6,853 and 11,050 μmol Trolox equivalents/100 g (db) were obtained for DPPH and ABTS, respectively. Four flavonoids catechin, quercetin, rutin and myricetin and two phenolic acids ferulic and sinapic were identified, these phenolic compounds may be responsible for the health benefits of quince.
... Reduction in the ratio of CD4 + :CD8 + T cells and suppression of macrophages, dendritic, mast cells, and interleukin-6 (IL-6) levels were revealed after a specific tissue was treated with Quercetin in pre-clinical studies ( Figure 1) [8][9]. Besides, Quercetin is expected to have an antiviral activity by acting as a zinc chelator and zinc ionophore [10]. However, because most of these studies were done using Quercetin in vitro with high concentration and in vivo studies cannot use the same doses, it showed minimum effect during clinical trials. ...
Coronavirus disease 2019 (COVID-19) is an
infectious disease caused by a new strain of
coronavirus, SARS-CoV-2. There are three
phases of COVID-19: early infection stage,
pulmonary stage, and hyper-inflammation stage.
It is essential to prevent lung or other organ
injuries by preventing phase-II and phase-III
using pharmacological or non-pharmacological
treatments. This case series study aims to
evaluate the safety and efficacy of Quercetin,
Bromelain, zinc, and vitamin C combination
supplements in patients with COVID-19. In this
study, twenty-two patients diagnosed (mean age
49.27, 68.18% male) with COVID-19 in Imam
Abdulrahman Alfaisal Hospital in Riyadh have
administrated Quercetin 800 mg, Bromelain 165
mg, zinc acetate 50 mg, and vitamin C 1 g once
daily as supplements for 3 to 5 days. The mean
levels of WBC, ANC, ALC, AMC, and AST, D
dimer were measured to investigate the safety
of the used treatment. we planned to measure
how long stay at the hospital, Chemistry profiles
like D dimer, serum ferritin, CRP, serum zinc,
and interleukin 6 as planned in the protocol and
measured not done for all parameters like zinc,
and interleukin 6 were not done as unavailable
facilities at lab of hospital Their mean values were
normal among all included patients before and
after taking the supplements. Therefore, the oncedaily
administration of these supplements was
found to be safe for patients infected with SARSCoV-
2 and may prevent the poor prognosis of the
disease. Randomized clinical trials are needed in
the future to ensure the efficacy of Quercetin,
Bromelain, zinc, and vitamin C combination.
The study was registered at clinicaltrials.gov
with the identifier: NCT04468139.
... Reduction in the ratio of CD4 + :CD8 + T cells and suppression of macrophages, dendritic, mast cells, and interleukin-6 (IL-6) levels were revealed after a specific tissue was treated with Quercetin in pre-clinical studies ( Figure 1) [8][9]. Besides, Quercetin is expected to have an antiviral activity by acting as a zinc chelator and zinc ionophore [10]. However, because most of these studies were done using Quercetin in vitro with high concentration and in vivo studies cannot use the same doses, it showed minimum effect during clinical trials. ...
Coronavirus disease 2019 (COVID-19) is an infectious disease caused by a new strain of coronavirus. There are three phases of COVID-19: early infection stage, pulmonary stage and hyper-inflammation stage respectively. It is important to prevent lung or other organs injuries by preventing phase-II and phase-III via pharmacological or non-pharmacological treatments. This was a case series study done on twenty-two patients confirmed to be infected with SARS-CoV-2 and diagnosed with COVID-19. Patients in this study have been used quercetin 800 mg, bromelain 165 mg, zinc acetate 50 mg and ascorbic acid 1 g once daily as supplements for 3 to 5 days during SARS-CoV-2 infection. The aim of this study is to evaluate the safety and efficacy of quercetin, bromelain, zinc and ascorbic acid combination supplements on patients with COVID-19. The mean levels of WBC, ANC, ALC, AMC and AST were normal among all included patients before and after taking quercetin, bromelain, zinc and ascorbic acid supplements (P-value >0.05). Quercetin 800 mg, bromelain 165 mg, zinc acetate 50 mg and ascorbic acid 1 g once daily supplements were safe for patients infected with SARS-CoV-2 and may prevent poor prognosis. Randomized clinical trials needed in the future to ensure the efficacy of quercetin, bromelain, zinc and vitamin C combination.
... In consumers with more than 29 mg of treatment with quercetin, the rate of death is 68% less than in consumers treated with less than 10 mg. Quercetin can reduce arterial blood pressure; however, QU cannot reduce BP in prehypertensive and normotensive models [17]. QU progresses the reduction in BP dose-dependently. ...
Cardiovascular diseases (CVD) are the leading causes of global death, increasing over time. Despite current novel improvements, it is still a major medical challenge. Quercetin (QU) is a flavonoid with anti-inflammatory, vasodilatory, antihypertensive, antiarrhythmogenic, and antiapoptotic effects. It can reduce low-density lipoprotein (LDL) and cholesterol oxidation and prevent endothelial dysfunction in CVD. Also, it can protect myocardial cells against oxidative stress and inflammation caused by free radicals. An updated review of the literature on the cardiovascular effects of quercetin was performed using PubMed, Embase, and Science Direct databases. The aim of this review is to summarize the various effects of quercetin on the cardiovascular system.
... A previous study demonstrated that quercetin has a relatively long half-life of 28 h, suggesting that regular onion consumption can maintain quercetin concentration at high levels [16]. In particular, continuous intake of quercetin through diet may promote the functional regulation of vascular endothelial cells, thereby preventing hypertension [17]. Furthermore, a recent study indicated that quercetin and its derivatives exert a cardioprotective effect and prevent various cardiovascular diseases (CVDs) [18]. ...
... Therefore, the protective effect of onions may be an important preventive strategy for CVD development as well as myocardial infarction and stroke associated with high mortality [22]. A previous study showed that quercetin exerts an antihypertensive effect through mechanisms such as reducing oxidative stress, inhibiting angiotensinconverting enzyme (ACE) activity, improving endothelial cell function, and directly acting on vascular smooth muscles [17]. For example, a crossover study using populations at risk for obesity showed that 150 mg of quercetin per day can reduce systolic blood pressure (BP) and plasma oxidized low-density lipoprotein (ox-LDL) levels [23]. ...
... Therefore, quercetin may substantially contribute to cardioprotection [75]. In conclusion, regular intake of quercetin through diet may contribute to the prevention of hypertension and health of blood vessels [17]. In the future, further elucidation of the relationship between the antihypertensive effect of quercetin and suppression of the cardiovascular system is warranted. ...
Onion consumption has been reported to be associated with a lower incidence of myocardial infarction and stroke. Quercetin found in onions may contribute to this effect. This review aimed to describe the role of quercetin in vascular endothelial dysfunction-related hypertension. It also described the effects of quercetin on blood pressure (BP) regulation, vascular endothelial cell health associated with cardiovascular disease (CVD), and possible mechanisms underlying these effects. To this end, several epidemiological, in vivo, and in vitro studies published in PubMed, ScienceDirect, and Web of Science were analyzed. Epidemiological studies have shown that onions and quercetin can lower BP level and improve vascular dysfunction. The antioxidant and anti-inflammatory effects of quercetin may contribute to antihypertensive effect and endothelial cell health. In particular, in vivo studies have demonstrated that quercetin and its metabolites inhibit the renin–angiotensin (RA) system and increase nitric oxide (NO) production, reactive oxygen species production, and vascular endothelial cell inflammation, thereby possibly contributing to the improvement of endothelial dysfunction. Thus, quercetin acts directly on vascular endothelial cells to block hypertension and potentially contributes to CVD prevention.
... Flavonoid juga dilaporkan meningkatkan ekspresi sintase oksida nitrat endotel yang membantu mengurangi tekanan darah, katekin menghambat ACE dengan melekat pada ion Zn atau dengan asam amino di situs aktif sehingga katekin memblokir aktivitas katalitik ACE dan katekin dapat bekerja sebagai ACEI(21,22).Selain katekin, dalam Uncaria gambir terdapat senyawa flavonoid berupa quarcetin. Quarcetin juga merupakan salah satu bagian dari flavonoid yang memiliki efek vasodilator, quarcetin dapat mengurangi stress oksidatif, meningkatkan fungsi endotel atau vaskular dan pengganggu RAS (rennin-angiotensin system).Pada studi epidemiologi telah menemukan hubungan antara asupan flavonoid dan penyakit kronis, yang menunjukkan efek perlindungan jantung yang kuat dari beberapa flavonoid salah satunya yaitu quarcetin(23). dosis uji yaitu dosis 1 (56 mg/grBB) dan dosis 2 (112 mg/grBB), kontrol positif menggunakan captopril 25 mg dan kontrol negatif menggunakan Na-CMC 0,5%. ...
Hipertensi merupakan peningkatan tekanan darah diatas normal yang terjadi secara bertahap dan bisa memburuk seiring waktu, hipertensi adalah satah satu penyakit degeneratif yang banyak diderita oleh masyarakat di seluruh dunia. Akar kayu bajakah kalalawit (Uncaria gambir (W.Hunter) Roxb) banyak digunakan secara empiris sebagai salah obat antihipertensi, mengandung antioksidan seperti flavonoid. Tujuan penelitian ini adalah untuk mengetahui aktivitas variasi dosis ektrak akar kayu bajakah kalalawit terhadap tekanan darah pada mencit jantan yang diinduksi hipertensi dengan Monosodium Glutamat (MSG) 8 mg selama 14 hari. penelitian ini menggunakan hewan coba mencit putih jantan galur swiss yang dibagi menjadi 4 kelompok yaitu kontol negatif, kontrol positif (captopril 25 mg), dosis 1 (56 mg/grBB dan dosis 2 (112 mg/grBB). Tekanan darah hewan diukur menggunakan sphygmomanometer sebelum induksi H-0, setelah induksi H-14 dan setelah pemberian ekstrak H-17. Analisis data dilakukan secara oneway ANOVA dilanjutkan dengan uji LSD (Least Significant Different). Hasil menunjukkan ekstrak bajakah kalalawit dengan dosis 56 mg dan 112 mg mampu menurunkan tekanan darah mencit, dimana hasil pengukuran tekanan darah tidak berbeda jauh antara dosis 2 dengan kontrol positif yang diberi captopril 25 mg. Flavonoid pada bajakah kalalawit yang berfungsi sebagai agen antihipertensi adalah katekin dan quarcetin yang bekerja dengan cara menghambat proses terbentuknya angiotensi I menjadi angiotensi II. Kesimpulannya pemberian ekstrak bajakah kalalawit pada dosis 56 mg dan 112 mg yang diberikan pada mencit hipertensi menunjukkan potensi sebagai antihipertensi. Kata kunci : bajakah kalalawit, ekstrak, hipertensi, MSG, Flavonoid
... Additionally, polyphenols play a part in the redox-sensitive PI3-kinase/Akt pathway's activation, which boosts NO generation. All of these mechanisms work together to lower blood pressure in hypertensive circumstances [68] (Fig. 3, Table 3) [69][70][71][72][73] ( Table 4) [74][75][76][77][78][79][80][81]. ...
Hypertension is a critical health problem. It is also the primary cause of coronary heart disease, stroke, and renal vascular disease. The use of herbal drugs in the management of any disease is increasing. They are considered the best immune booster to fight against several types of diseases. To date, the demand for herbal drugs has been increasing because of their excellent properties. This review highlights antihypertensive drugs, polyphenols, and synbiotics for managing hypertension. Evidence is mounting in favour of more aggressive blood pressure control with lower adverse effects, especially for specific patient populations. This review aimed to present contemporary viewpoints and novel treatment options, including cutting-edge technological applications and emerging interventional and pharmaceutical therapies, as well as key concerns arising from several years of research and epidemiological observations related to the management of hypertension.
... Unfortunately, the mechanisms by which quercetin affects blood pressure remain partly unclear [24]. Different mechanisms of action have been proposed, including the following: reduction in oxidative stress, interference with the RAAS system (specifically ACE inhibitors), and /or improvements in endothelial and/or vascular function [25]. Furthermore, in accordance with the inherent features of diabetes and CKD [26], blood lactate levels showed a chronic increment in all diabetic groups. ...
Diabetic Kidney Disease (DKD) is a major microvascular complication for diabetic patients and is the most common cause of chronic kidney disease (CKD) and end-stage renal disease. Antidiabetic drugs, such as metformin and canagliflozin, have been shown to exert renoprotective effects. Additionally, quercetin recently showed promising results for the treatment of DKD. However, the molecular pathways through which these drugs exert their renoprotective effects remain partly unknown. The current study compares the renoprotective potential of metformin, canagliflozin, metformin + canagliflozin, and quercetin in a preclinical rat model of DKD. By combining streptozotocin (STZ) and nicotinamide (NAD) with daily oral N(ω)-Nitro-L-Arginine Methyl Ester (L-NAME) administration, DKD was induced in male Wistar Rats. After two weeks, rats were assigned to five treatment groups, receiving vehicle, metformin, canagliflozin, metformin + canagliflozin, or quercetin for a period of 12 weeks by daily oral gavage. Non-diabetic vehicle-treated control rats were also included in this study. All rats in which diabetes was induced developed hyperglycemia, hyperfiltration, proteinuria, hypertension, renal tubular injury and interstitial fibrosis, confirming DKD. Metformin and canagliflozin, alone or together, exerted similar renoprotective actions and similar reductions in tubular injury and collagen accumulation. Renoprotective actions of canagliflozin correlated with reduced hyperglycemia, while metformin was able to exert these effects even in the absence of proper glycemic control. Gene expression revealed that the renoprotective pathways may be traced back to the NF-κB pathway. No protective effect was seen with quercetin. In this experimental model of DKD, metformin and canagliflozin were able to protect the kidney against DKD progression, albeit in a non-synergistic way. These renoprotective effects may be attributable to the inhibition of the NF-κB pathway.
... 49 Quercetin (5,7,3 ′ ,4 ′ -avan-3-ol), a pentahydroxyavone with ve hydroxyl groups, is an abundant avonoid found in apples, onions, red wine and berries. 50 It has four active groups: a dihydroxy group in the A ring, o-dihydroxy group B, C ring C2, C3 double and carbonyl groups. The phenolic group and double bonds present rationales for the biological properties of quercetin. ...
In the contemporary world, evolution of the scientific field has reached an elevation but has its own intricacies. It is necessary to use naturally occurring materials, which are often incorporated into modern therapeutics and have made major contributions. Generated medical waste needs to be processed to ensure that clean-up is not messy. In many cases, the cost of waste disposal is greater than the cost of the starting materials. It is important to prevent, or at least minimize, the formation of hazardous products that are environmentally harmful. In this study, we review the various applications of phytochemicals, such as curcumin, EGCG, tannic acid, cellulose, ascorbic acid, aloe vera and quercetin, for the healing of chronic wounds (e.g., incisional, diabetic and burn wounds), along with antiviral and antibacterial properties, with an emphasis on hydrogels fabricated from biopolymers.
