Search

Flavonoids have shown anti-hypertensive and anti-atherosclerotic properties: the impact of habitual flavonoid intake on vascular function, central haemodynamics and arterial stiffness may be important. We investigated the relationship between habitual flavonoid consumption and measures of central blood pressure and arterial stiffness. We performed cross-sectional analysis of 381 non-smoking healthy older adults (mean age 66·0 (sd 4·1) years; BMI, 26·4 (sd 4·41) kg/m2; 41 % male) recruited as part of the Australian Research Council Longevity Intervention study. Flavonoid intake (i.e. flavonols, flavones, flavanones, anthocyanins, isoflavones, flavan-3-ol monomers, proanthocyanidins, theaflavins/thearubigins and total consumption) was estimated from FFQ using the US Department of Agriculture food composition databases. Measures of central haemodynamics and arterial stiffness included systolic blood pressure (cSBP), diastolic blood pressure (cDBP), mean arterial pressure (cMAP) and augmentation index (cAIx). After adjusting for demographic and lifestyle confounders, each sd/d higher intake of anthocyanins ((sd 44·3) mg/d) was associated with significantly lower cDBP (−1·56 mmHg, 95 % CI −2·65, −0·48) and cMAP (−1·62 mmHg, 95 % CI −2·82, −0·41). Similarly, each sd/d higher intake of flavanones ((sd 19·5) mg/d) was associated with ~1 % lower cAIx (−0·93 %, 95 % CI −1·77, −0·09). These associations remained significant after additional adjustment for (1) a dietary quality score and (2) other major nutrients that may affect blood pressure or arterial stiffness (i.e. Na, K, Ca, Mg, n-3, total protein and fibre). This study suggests a possible benefit of dietary anthocyanin and flavanone intake on central haemodynamics and arterial stiffness; these findings require corroboration in further research.

Wound is known as disruption in the integrity of a tissue. The mechanisms of regeneration and tissue repair consist of a series of molecular and cellular events that occur after the onset of a tissue lesion to rebuild the damaged tissue. The remodelling phases of the exudative, proliferative, and extracellular matrix are concurrent events that occur through the interaction of complex processes involving soluble mediators, blood cells and parenchymal cells. Exudative phenomena that occur after injury, lead to tissue edema growth. The proliferative stage aims to minimize the area of tissue damage by myofibroblasts and fibroplasia contracting. Angiogenesis and reepithelialisation processes can still be observed at this point. Endothelial cells are capable of differentiating into mesenchymal components and this distinction seems to be finely coordinated by a series of signalling proteins. Many of the medicines available today is derived from natural sources. Flavonoids are essential components of the human diet apart from their physiological functions in plants, even though they are not considered as nutrients. In this review, naturally occurring flavonoid is discussed which occur in citrus fruits, vegetables, nuts, and beverages like coffee, tea, and red wine, and also in medical herbs. They exhibit different pharmacological actions, like antioxidant, anti-allergic, anti-bacterial, anti-inflammatory, anti-mutagenic and anti-cancer activity. One of the flavanones is Naringenin which is the ordinary dietary poly-phenolic constituent of the citrus fruits (grapefruit and oranges) and vegetables. It is beneficial in various neurological, cardiovascular, gastrointestinal, rheumatological, metabolic, malignant disorders, and functionally, this ameliorative effect of naringenin is primarily attributed to its anti-inflammatory (via inhibiting staffing of cytokines and inflammatory transcription factors) and anti-oxidant (via scavenging of free radicals, bolstering of endogenous antioxidant defence system and metal ion chelation) effects

BACKGROUND AND OBJECTIVES The prevalence of NCDs (Non-communicable Diseases) was increasing in Indonesia. The antioxidants have been known as a potential nutrient that prevent and reduce the risk of the NCDs. Flavonoid is the most abundant antioxidant in plant-source diet and commonly consumed in Indonesia. In other side, there was not a flavonoid database based on various Indonesian foods. The aim of this study was to build a flavonoid database based on Indonesian foods. METHODS The selected food items used food items of Indonesian Total Diet Survey 2014 (SDT 2014). We did not determine the flavonoids contents in the laboratories, we compiled its content by using the United States Department of Agriculture Database and related refferences. The estimation for calculating flavonoid content used USDA Database technique. The total flavonoid content for each food items were summarized into six flavonoid subclasses (anthocyanidine, flavan-3-ols, flavanone, flavone, flavonols, dan isoflavone). The total flavonoid content was presented by mg/100 gram of each food items. RESULTS There were 13 food groups and 1,203 food items in this database. There were 654 food items had flavonoid content. The highest mean of flavonoid content was legumes (45.36 mg/100 g). The vegetables and products were the food group with the most foods containing flavonoid (120 food items). CONCLUSION There were 654 food items in Indonesian foods contained flavonoid. The highest mean of flavonoid content were legumes. This findings can provide valuable information for Indonesian people to increase dietary flavonoid intake.

Phloretin (PHL) is an abundant dietary flavonoid possessing several pharmacological activities but with poor aqueous solubility and low bioavailability. Herein, two new cocrystals of phloretin-nico...

A lack of data regarding flavonoid food composition and flavonoid intake has limited the ability to evaluate proposed health benefits effects in populations. We estimated the dietary flavonoids intake of the Brazilian population based on the diet composition obtained through two dietary surveys, which were available from a Food Service and Brazilian Household Budget Survey, using the USDA and Phenol-Explorer databases. The mean daily estimated flavonoid intake was similar when calculated using the USDA and Phenol-Explorer databases in the Household Budget Survey (56.32 mg/day and 64.22 mg/day, respectively). Similar results were observed when calculated using both databases in a Food Service (86.66 mg/meal and 106.33 mg/meal, respectively). The major class contributor was flavanones mainly from oranges, followed by flavonols mainly from onions and apples. The main difference was found in the third flavonoid class, anthocyanidins and flavan-3-ol using the USDA and Phenol-Explorer databases, respectively. In conclusion, there was a balance of intake between the five flavonoid subclasses, which is determined to be important to diversity in a diet. Despite some technical features, both databases are a useful source of food flavonoid contents, but the method of data collection used to estimate the intake impairs great differences in the results.

Background:Flavonoids are a diverse group of plant constituents with demonstrated neuroprotective and anti-tumor effects. Flavonoid intake may decrease the risk of glioma, but the possibility of an association has not yet been investigated in humans.Objectives:We evaluated the association between dietary flavonoid consumption and the risk of glioma.Methods:We followed participants in the female Nurses’ Health Study (1984–2014; n = 81,688) and Nurses’ Health Study II (1991–2017; n = 95,228) and the male Health Professionals Follow-Up Study (1986–2014; n = 49,885). We used multivariable-adjusted Cox proportional hazards regression models to evaluate the associations between average long-term (up to 30 years) or recent (up to 12 years) dietary flavonoid intake (total flavonoids and each of 6 subclasses) and risks of incident glioma. Flavonoid intake was derived from validated quadrennial FFQs. Incident glioma was self-reported and confirmed by a medical record review or was determined by a medical record review after death.Results:We documented 536 incident cases of glioma across 5,936,386 person-years of follow-up. Long-term total flavonoid, flavan-3-ol, and polymeric flavonoid (polymer) intakes were associated with decreased glioma risks in pooled analyses comparing the highest to lowest quintiles of consumption [HR, 0.79 (95% CI, 0.59–1.05; P-trend = 0.04) for total flavonoids; 0.76 (95% CI, 0.57–1.01; P-trend = 0.04) for flavan-3-ols; and 0.82 (95% CI, 0.61–1.09; P-trend = 0.05) for polymers]. Associations with recent intake were weaker. There were no associations with other flavonoid subclasses. After additional adjustment for tea consumption, there were no associations between flavan-3-ol or polymer consumption and glioma.Conclusions:Increased dietary intakes of flavan-3-ol and polymeric flavonoids, especially those predominant in tea, were associated with decreased glioma risks in a prospective cohort of men and women.

The aim of this study was to identify the health risk factors associated with flavonoid intake in cohort studies investigating the association between dietary polyphenols and the risk of cardiovascular disease (CVD). A systematic search of the PubMed and EMBASE databases was performed. Prospective studies with the background characteristics given for categories of flavonoid intake were eligible to inclusion. A bivariate meta-analysis summarising the intercepts and slopes of the linear regression and a dose-response meta-analysis of differences in means were used to analyse the relationships. The intake of total flavonoids was inversely associated with BMI, alcohol consumption, saturated fat intake, and current smoking, and positively associated with vitamin E, folate, fibre, beta-carotene intake, multivitamin supplement use, and high physical activity. The results of this study underline the importance of considering the association between dietary flavonoid consumption and CVD risk in the context of a healthy lifestyle.

Background: Naringenin belongs to the class flavanones, and chemically it is known as 5,7-dihydroxy-2-(4-hydroxyphenyl) chroman-4-one. It is one of the dietary poly-phenolic constituents of the citrus fruits and vegetables. Naringenin possesses excellent antioxidant, antiinflammatory, and antimicrobial activities. These activities promote wound healing activity. Naringenin has been incorporated in the gel base to be applied on the wounded skin. The wound healing property of naringenin gel has not been studied extensively in the literature to date. Objective: The present study aims to unveil the wound healing property of naringenin gel formulation on excision and incision model. Materials and Methods: 0.5% and 1% naringenin was incorporated in a carbopol gel base formulation and evaluated for physicochemical parameters. Incision and excision wound models were used to study wound contraction, tensile strength, healing index, the period of epithelization and histopathological parameters. Antimicrobial activity was performed using agar plate method. Results: Naringenin (0.5% and 1%) treatment shows a significant increase in the percentage of wound contraction, good healing index and shorter epithelization period. Histopathology of naringenin gel treated wound tissue showed more fibroblasts, less macrophage infiltration, and wellformed collagen fibers as compared to control. In incision wound model, the animals were treated with 0.5% and 1% naringenin gel for nine days and showed a significant increase in the tensile strength. Naringenin exerts antimicrobial activity against fungus and E. coli. Conclusion: The present study explored potent wound healing activity of naringenin gels.

Background Within- and between-person variation in nutrient intake is well established, but little is known about variability in dietary flavonoid intake, including the effect of seasonality. Methods Within- and between-individual variability of flavonoid intake, and intake of flavonoid subclasses was examined in older adults (n = 79; mean age 70.1 y (range: 60y-80y)), using three separate 4-day weighed food records (WFR) collected approximately 4 months apart. The effects of seasonality were also examined. Mixed-effects linear regression models were used to estimate within- and between-individual variance components for flavonoids and subclasses. The number of days of dietary assessment required for a high level of hypothetical accuracy was calculated from variance ratios. Results Within- and between-individual variability was high for flavonoid intake, and intake of flavonoid subclasses, with variance ratios > 1. It was calculated that six days of WFR data are required for total flavonoid intake, and between 6 and 10 days was required for flavonoid subclasses. There was no effect of seasonality for total flavonoid intake or intake of flavonoid subclasses, with the exception that flavan-3-ol and flavanone intakes which were relatively low in summer, and in summer and winter, respectively. Conclusion While the effects of seasonality on total flavonoid intake may be small, within- and between-individual variation associated with flavonoid intake assessment appears to be substantial across 12 days of WFR data in older adults. It is recommended that a minimum of 6 days of weighed food records are collected to minimise the impact of within- and between-individual variability on total flavonoid intake assessments in this population. Electronic supplementary material The online version of this article (10.1186/s12937-017-0309-7) contains supplementary material, which is available to authorized users.

This study aimed to investigate the association between dietary flavonoid intake and the prevalence of obesity using body mass index (BMI), waist circumference, and percent body fat (%BF) according to sex among Korean adults. Based on the Korean Health and Nutrition Examination Survey 2008–2011, 23 118 adults in Korea were included. Dietary intakes were obtained using 24-h dietary recall data. A higher total intake of flavonoid was associated with a lower prevalence of obesity in women, based on %BF (odds ratio [95% confidence interval] = 0.82 [0.71–0.94]), and abdominal obesity (0.81 [0.71–0.92]). The intake of flavonols (0.88 [0.78–0.99]), flavanones (0.81 [0.72–0.92]), flavanols (0.85 [0.74–0.97]), isoflavones (0.85 [0.75–0.96]), and proanthocyanidins (0.81 [0.71–0.92]) was inversely associated with abdominal obesity, and a higher intake of flavanones (0.87 [0.76–0.99]) and proanthocyanidins (0.85 [0.75–0.98]) was associated with a lower prevalence of obesity, with respect to %BF in women. In contrast, the intake of flavonols (1.16 [1.02–1.33]), flavanones (1.18 [1.04–1.35]), and anthocyanidins (1.27 [1.11–1.46]) was positively associated with obesity based on BMI in men. In conclusion, high intake of dietary flavonoids may be associated with a decreased prevalence of abdominal obesity and obesity, based on %BF, among women. Novelty Higher flavonoid intake was associated with decreased prevalence of abdominal obesity and obesity based on %BF in Korean women. However, in men, the intake of flavonols, flavanones, and anthocyanidins was positively associated with obesity as given by BMI.

Luteolin, a polyphenolic plant flavonoid, has been attributed with numerous beneficial properties like anti-cancer, antioxidant, and anti-inflammatory action. Luteolin has been reported earlier to be neuroprotective in models of spinal cord injury and traumatic brain injury and also induces neurite outgrowth in PC12 cells. However, the effect of luteolin on early differentiation, which might be important for its beneficial effects, is unknown. In this report, we show that luteolin negatively affects early differentiation of embryonic stem cells, hampering the formation of embryoid bodies. At later stages of differentiation, luteolin specifically inhibits neuronal differentiation, where the expression of early neuronal markers is suppressed, whereas luteolin treatment does not inhibit expression of meso- and endodermal markers. Further, in a developing zebrafish model, luteolin treatment leads to fewer numbers of mitotic cells in the brain. These specific effects of luteolin on neuronal differentiation could possibly be due to its ability to inhibit the lysine acetyltransferase, p300, since the structurally closely related p300 non-inhibitor flavonoid, apigenin, does not inhibit neuronal differentiation. These results show that luteolin perturbs neuronal differentiation of embryonic stem cells.

A series of dietary flavonoid acacetin 7-O-methyl ether derivatives were computationally designed aiming to improve the selectivity and potency profiles against monoamine oxidase (MAO) B. The designed compounds were evaluated for their potential to inhibit human MAO-A and -B. Compounds 1c, 2c, 3c, and 4c were the most potent with a Ki of 37 to 68 nM against MAO-B. Compounds 1c–4c displayed more than a thousand-fold selectivity index towards MAO-B compared with MAO-A. Moreover, compounds 1c and 2c showed reversible inhibition of MAO-B. These results provide a basis for further studies on the potential application of these modified flavonoids for the treatment of Parkinson’s Disease and other neurological disorders.

The molecular nature, antioxidant, and anticancer actions of the dietary flavonoid daidzein binding to two types of β-lactoglobulin (βLG) are investigated in this work by using different kinds of spectroscopic techniques, electrochemical analysis, molecular docking, and molecular dynamics simulation. The results showed that hydrogen bonds and van der Waals interactions played a major role in the development of the stable complex. It may be deduced from molecular docking studies and competitive assays that daidzein binds to the outer surface of βLG with appropriate binding energies. The results of molecular dynamics showed the creation of a relatively stable complex in which daidzein binding reduced the flexibility of key residues in the binding site. In terms of the masking effect of βLG, the best antioxidant activity was found at low concentrations of the βLG-daidzein complex. After 48 hours of exposure to a 50 μM mixture of βLG and daidzein, the complexes showed increased anticancer activity with maximal mortalities of 38.62 and 47.08% for HeLa and MCF-7 cells, respectively. The improvement of daidzein's solubility and anticancer activity as a result of its complexation with βLG, as well as its light and heat stability, could be a beneficial approach in the food and pharmaceutical industries.

Flavonoids are polyphenolic phytochemicals with health-promoting properties, yet knowledge about their intake in at-risk populations is limited. This study sought to estimate intakes of total flavonoids and six flavonoid classes in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study, determine if differences in intakes exist by race (African American (AA) and White (W)) and income (&lt, or &gt, 125% Federal poverty guidelines), and compare intakes to those of a nationally representative population with similar demographic and socioeconomic characteristics. Data transformation normalized the flavonoid intake distributions prior to conducting statistical tests. With the exception of the flavanone class, flavonoid intakes of AAs were significantly lower than those of W (p &lt, 0.01), regardless of other potential mediating factors including sex, age, and income. Total flavonoid intakes in HANDLS did not differ from intakes in the nationally representative study, but anthocyanidin and flavone intakes were lower, and race specific differences were found for several flavonoid classes. These findings imply that benefits attributable to flavonoid consumption may not be experienced equally by AAs and Whites, nor in vulnerable populations such as that represented by HANDLS relative to the U.S. population, and may play a role in observed health disparities.

Didymin (isosakuranetin 7-O-rutinoside) is an orally bioactive dietary flavonoid glycoside first found in citrus fruits. Traditionally, this flavonoid has long been used in Asian countries as a dietary antioxidant. Recent studies have provided newer insights into this pleiotropic compound, which could regulate multiple biological activities of many important signaling molecules in health and disease. Emerging data also presented the potential therapeutic application of dietary flavonoid glycoside didymin against cancer, neurological diseases, liver diseases, cardiovascular diseases, and other diseases. In this review, we briefly introduce the source and extraction methods of didymin, and summarize its potential therapeutic application in the treatment of various diseases, with an emphasis on molecular targets and mechanism that contributes to the observed therapeutic effects. The dietary flavonoid didymin can be used to affect health and disease with multiple therapeutic targets, and it is anticipated that this review will stimulate the future development of this potential dietary medicine.

Toll-like receptor 2 (TLR2) responses are involved in various inflammatory immune disorders. Phloretin is a naturally occurring dietary flavonoid that is abundant in fruit. Here, we investigated whether the anti-inflammatory activity of phloretin is mediated through TLR2 pathways, and whether phloretin acts as an inhibitor of TLR2/1 heterodimerization using the TLR2/1 agonist Pam3CSK4. We tested the effects of phloretin on tumor necrosis factor (TNF)-&alpha, production induced by various TLRs using known TLR-specific agonists. Phloretin significantly inhibited Pam3CSK4-induced TRL2/1 signaling in Raw264.7 cells compared to TLR signaling induced by the other agonists tested. Therefore, we further tested the effects of phloretin in human embryonic kidney (HEK) 293-hTLR2 cells induced by Pam3CSK4, and confirmed that phloretin has comparable inhibition of TLR2/1 heterodimerization to that induced by the known TLR2 inhibitor CU-CPT22. Moreover, phloretin reduced the secretion of the inflammatory cytokines TNF-&alpha, and interleukin (IL)-8 in Pam3CSK4-induced HEK293-hTLR2 cells, whereas it did not significantly reduce these cytokines under Pam2CSK4-induced activation. Western blot results showed that phloretin significantly suppressed Pam3CSK4-induced TLR2 and NF-&kappa, B p65 expression. The molecular interactions between phloretin and TLR2 were investigated using bio-layer interferometry and in silico docking. Phloretin bound to TLR2 with micromolar binding affinity, and we proposed a binding model of phloretin at the TLR2&ndash, TLR1 interface. Overall, we confirmed that phloretin inhibits the heterodimerization of TLR2/1, highlighting TLR2 signaling as a therapeutic target for treating TLR2-mediated inflammatory immune diseases.

Metallopeptidases of the M49 family are proteolytic enzymes that contain highly conserved HEXXXH motif and whose catalytic activity depends on the zinc cation [1]. Dipeptidyl peptidase III (DPP III) is the best characterized member of this family with distribution detected in almost all forms of life. The physiological role of DPP III has not been precisely determined, however it is assumed that it is involved in intracellular protein catabolism, mammalian pain modulatory system, and in the defense against oxidative stress. Flavonoids belong to the group of polyphenolic compounds that are ubiquitous in plants. They are important component of human diet and seem to have various pharmacological actions [2]. In this study, we selected 15 dietary flavonoids belonging to four different structural subclasses to investigate their potential inhibitory activity (at the physiological concentration i.e., 100 μM) against human DPP III. Inhibition of DPP III activity was determined using the spectrophotometric method [3] with minor modifications. For that purpose, purified recombinant human DPP III was briefly preincubated with a flavonoid in buffered solution and the enzymatic reaction was started with a Arg-Arg β- naphthylamide as a substrate. After the incubation time the reaction was stopped and the absorbance at 530 nm was measured. The percentage of enzyme inhibition (% inh.) was calculated by comparing the enzymatic activity without (normal activity) and with a flavonoid (inhibited activity). The results, obtained by in vitro assay showed that all analyzed dietary flavonoids have inhibitory effect against human DPP III hydrolytic activity at given concentration. The strongest inhibition (% inh. > 90) has been obtained with galangin, genistein, fisetin, kaempferol, and luteolin. A slightly lower inhibition (% inh. 50-90) has been observed for 3, 6- dihydroxyflavone, 3, 7- dihydroxyflavone, 6- hydroxyflavone, apigenin, morin and quercetin, while 3-hydroxyflavone, chrysin, flavone and flavanone have shown an inhibition of less than 50%. These data indicate that the presence and exact distribution of different structural groups on dietary flavonoids are important for their inhibitory properties. [1] N. D. Rawlings, F. R. Morton, C. Y. Kok, J. Kong, and A. J. Barrett Nucleic Acids Res 36 (2008) D320– D325. [2] S. Kumar, A. K. Pandey, Sci. World J. (2013) 162750. [3] M. Abramić, M. Zubanović, Lj. Vitale, Biol. Chem. Hoppe-Seyler 369 (1988) 29–38.

The metabolic oxidation pathways of dietary flavonoid eriodictyol (Er) are not very well-probed. In the present work, the electrochemical oxidation behavior of Er was studied in aqueous Britton-Robinson (B-R) buffer solution using cyclic voltammetry (CV), chronoamperometry (CA), and bulk-electrolysis (BE). The oxidation products and reaction pathways of Er in the absence and the presence of glutathione (GSH) were proposed and identified in view of the results obtained by ultra-high-performance liquid chromatography coupled with mass spectrometry (UPLC-MS). In the absence of GSH, eriodictyol shows one quasi-reversible oxidation process at E-1/2=0.305V, followed by a totally irreversible anodic peak at a more positive potential (E-p(a)=1.05V vs. Ag/AgCl, 3M KCl). Putatively, the first process corresponds to the oxidation of the catechol moiety on the B ring of Er while the second one is attributed to the oxidation of the resorcinol moiety on the A ring. In the presence of GSH, however, the anodic oxidation of Er was proposed to be an ECEC-type mechanism. The Er molecule first underwent a two-electron oxidation coupled with loss of two-proton to generate the corresponding quinone, which was either reduced to the original Er molecule by GSH, or further interacted with GSH to produce mono- and bi- glutathione conjugates of Er. The proposed mechanism was confirmed by digital simulation of the cyclic voltammograms.

Background: Dietary flavonoids have been related to lower risks of various chronic diseases, but it is unclear whether flavonoid intake in midlife helps to maintain good health and wellbeing in aging. Objective: We examined the relation of flavonoid intake in midlife with the prevalence of healthy aging. Design: We included 13,818 women from the Nurses’ Health Study with dietary data and no major chronic diseases in 1984‐1986 when they were aged in their late 50s (median age: 59 y); all women provided information on multiple aspects of aging an average of 15 yl ater. Intakes of 6 major flavonoid subclasses in midlife were ascertained on the basis of averaged intakes of flavonoid-rich foods from 2 food-frequency questionnaires(1984‐1986).Wedefinedhealthycomparedwithusualaging as of age 70 y; healthy aging was based on survival to $ 70 yw ith maintenance of 4 health domains (no major chronic diseases or major impairments in cognitive or physical function or mental health). Results: Of women who survived until $70 y of age, 1517 women (11.0%) met our criteria for healthy aging. Compared with women in the lowest quintile of intake, women in the highest quintile of intake of several flavonoid subclasses at midlife had greater odds of healthy aging. After multivariable adjustment, ORs were as follows: flavones, 1.32 (95% CI: 1.10, 1.58); flavanone, 1.28 (95% CI: 1.08, 1.53); anthocyanin, 1.25 (95% CI: 1.04, 1.50); and flavonol, 1.18 (95% CI: 0.98, 1.42) (all Ptrend # 0.02). Consistently, greater intakes of major sources of these flavonoids (i.e., oranges, berries, onions, and apples) were associated with increased odds of healthy aging. We showed no association with flavan-3-ol monomers (P-trend = 0.80) or polymers (P-trend = 0.63). Conclusion: Higher intake of flavonoids at midlife, specifically flavones,flavanones,anthocyanins,andflavonols,isassociatedwithgreater likelihood of health and wellbeing in individuals surviving to older ages. Am J Clin Nutr 2014;100:1489‐97.

Flavonoids, a broad category of nonnutrient food components, are potential protective dietary factors in the etiology of some cancers. However, previous epidemiological studies showing associations between flavonoid intake and cancer risk have used unvalidated intake assessment methods. A 62-item food frequency questionnaire (FFQ) based on usual intake of a representative Australian adult population sample was validated against a 3-day diet diary method in 60 young adults. Spearman's rank correlations showed 17 of 25 individual flavonoids, 3 of 5 flavonoid subgroups, and total flavonoids having strong/moderate correlation coefficients (0.40-0.70), and 8 of 25 individual flavonoids and 2 of 5 flavonoid subgroups having weak/insignificant correlations (0.01-0.39) between the 2 methods. Bland-Altman plots showed most subjects within ±1.96 SD for intakes of flavonoid subgroups and total flavonoids. The FFQ classified 73-90% of participants for all flavonoids except isorhamnetin, cyanidin, delphinidin, peonidin, and pelargonidin; 73.3-85.0% for all flavonoid subgroups except Anthocyanidins; and 86.7% for total flavonoid intake in the same/adjacent quartile determined by the 3-day diary. Weighted kappa values ranged from 0.00 (Isorhamnetin, Pelargonidin) to 0.60 (Myricetin) and were statistically significant for 18 of 25 individual flavonoids, 3 of 5 subgroups, and total flavonoids. This FFQ provides a simple and inexpensive means to estimate total flavonoid and flavonoid subgroup intake.

In recent years, flavonoids have been revealed to be helpful in the treatment of many diseases. Rutin (3,3',4',5,7-pentahydroxyflavone-3-rhamnoglucoside) is an important flavonoid that is consumed in the daily diet. It is also known as vitamin P and quercetin-3-O-rutinoside. In addition, it is found in many food items, vegetables, and beverages. The cytoprotective effects of rutin, including gastroprotective, hepatoprotective, and anti-diabetic effects, have been shown in several studies. Furthermore, rutin has several pharmacological effects such as anti-inflammatory and anti-glycation activities.This work reviewed characteristic, pharmacokinetic, and metabolic effects of rutin in all experimental and human studies.Based on the above summarized effects of rutin, this flavonoid appears to be a potent component that could be considered in the treatment of several gastrointestinal diseases and diabetes.

Two novel syntheses of the flavone luteolin are described. In the first, 3,5-dimethoxyphenol was converted to 2-hydroxy-4,6-dimethoxyacetophenone and then by condensation with 3,4-dimethoxybenzaldehyde to 2′-hydroxy-3,4,4′,6′-tetramethoxychalcone. In the second, the chalcone step was prepared in which 3,5-dimethoxyphenol was acylated with 3,4-dimethoxycinnamoyl chloride. The chalcone was then cyclised with iodine and demethylated with pyridine hydrochloride to form luteolin in 47% and 40% overall yield, respectively. Several disadvantages of previous syntheses like long reaction time, harsh reaction conditions and low overall yield have been overcome.

Knowing the dietary flavonoid intake of individuals and populations is the first step to clearly understand their health effects. Dietary flavonoid intake studies have been hampered by the lack of flavonoid food composition data. The objectives of this study were to estimate intakes of individual, classes and total flavonoids in the US adults; to evaluate the effects of socio-demographic factors on the flavonoid consumption patterns; and to establish major dietary sources of flavonoids. We calculated flavonoid intakes using the most updated USDA flavonoid and isoflavone databases, and the National Health and Nutrition Examination Survey (NHANES) III 24-h dietary recall (DR). Estimated mean total flavonoid intake by US adults was 344.83 ± 9.13 mg/day. The flavan-3-ols (191.99 ± 6.84 mg/day) were the most abundant flavonoid class. The three most dominant individual flavonoids were catechin, epicatechin and polymers. Tea, wine, beer, citrus fruits and apples were the most important sources of total flavonoid intakes in the US adults.

Dietary flavonoids and lignans may protect against several chronic diseases, but there is little evidence on the relationship between flavonoid and lignan intake and mortality. We investigated the association between both all-cause and specific-cause mortality and intake of flavonoids and lignans in the Spanish European Prospective Investigation into Cancer and Nutrition (EPIC-Spain) cohort.The EPIC-Spain study follows 40,622 participants (38% men) aged 29-69 years. A validated diet history questionnaire was administered at recruitment. A food composition database was compiled based on US Department of Agriculture and Phenol-Explorer databases. Cox proportional hazards models, adjusted for confounders, were used in the analyses.During a mean follow-up of 13.6 years, 1915 deaths were reported, with 416 from cardiovascular diseases (CVDs) and 956 from cancer. After adjustment for several potential confounders, the hazard ratios (HRs) for the highest versus the lowest quintile of dietary flavanone and flavonol intakes were 0.60 (95% confidence interval = 0.38-0.94) and 0.59 (0.40-0.88). Total flavonoid intake was also associated with a decrease in all-cause mortality (0.71 [0.49-1.03]). Lignan intake was not associated with all-cause mortality. In cause-specific mortality analyses, using competing risk regressions, doubling total flavonoid intake was inversely related to mortality from CVD (HR for log2 0.87 [0.77-0.98]), but not to mortality from either cancer (HR for log2 0.96 [0.89-1.04]) or other causes (HR for log2 0.97 [0.87-1.09]).A diet high in flavonoids, particularly in flavanones and flavonols, is associated with a reduction in all-cause mortality, mainly of mortality from CVD.

Objective: To examine the effect of galangin on hyperglycemia-mediated oxidative stress in streptozotocin (STZ)-induced diabetic rats. Methods: Diabetes was induced by intraperitoneal administration of low-dose STZ (40 mg/kg body weight (BW)) into male albino Wistar rats. Galangin (8 mg/kg BW) or glibenclamide (600 µg/kg BW) was given orally, once daily for 45 days to normal and STZ-induced diabetic rats. Results: Diabetic rats showed significantly increased levels of plasma glucose, thiobarbituric acid reactive substances, lipid hydroperoxides, and conjugated dienes. The levels of insulin and non-enzymatic antioxidants (vitamin C, vitamin E, reduced glutathione) and the activity of enzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase (GST)) were decreased significantly in diabetic control rats. These altered plasma glucose, insulin, lipid peroxidation products, enzymatic and non-enzymatic antioxidants ions were reverted to near-normal level after the administration of galangin and glibenclamide. Conclusion: The present study shows that galangin decreased oxidative stress and increased antioxidant status in diabetic rats, which may be due to its antidiabetic and antioxidant potential.

The last few decades have seen a resurgence of interest among the scientific community in exploring the efficacy of natural compounds against various human cancers. Compounds of plant origin belonging to different groups such as alkaloids, flavonoids and polyphenols evaluated for their cancer preventive effects have yielded promising data, thereby offering a potential therapeutic alternative against this deadly disease. The flavonol fisetin (3,3′,4′,7-tetrahydroxyflavone), present in fruits and vegetables such as strawberries, apple, cucumber, persimmon, grape and onion, was shown to possess anti-microbial, anti-inflammatory, anti-oxidant and more significantly anti-carcinogenic activity when assessed in diverse cell culture and animal model systems. The purpose of this review is to update and discuss key findings obtained till date from in vitro and in vivo studies on fisetin, with special focus on its anti-cancer role. The molecular mechanism(s) described in the observed growth inhibitory effects of fisetin in different cancer cell types is also summarized. Moreover, an attempt is made to analyze the direction required for future studies that could lead to the development of fisetin as a potent chemopreventive/chemotherapeutic agent against cancer.

Quercetin, a dietary-derived flavonoid, is ubiquitous in fruits and vegetables and plays important roles in human health by virtue of its antioxidant activity.This study was conducted to investigate the possible modulatory effect of quercetin against hepatic lipemic-oxidative injury in rats fed with a high cholesterol diet (HCD), and to highlight the underlying mechanisms of such effect.Different groups of male Sprague-Dawley rats were used; one group was treated by gavage with HCD cocktail (1 mL/100 g) whereas another group was orally administered HCD-enriched with quercetin (15 mg/kg). Corresponding control animals were also used.Quercetin administration significantly decreased liver triglycerides (24%), liver total cholesterol (TC) (22%), serum TC (20%), serum low-density lipoprotein cholesterol (31%), and duplicated serum high-density lipoprotein cholesterol (HDL-C). This study also revealed that quercetin administration significantly reduced the activity of serum alanine aminotransferase (41%), aspartate aminotransferase (51%), and γ-glutamyl transpeptidase (G-GT) (35%). Significant inhibition of thiobarbituric acid-reacting substances (40%), together with a valuable enhancement of reduced glutathione (GSH) content (53%) in the liver homogenates, was observed. In addition, quercetin-treated hypercholesterolemic animals exhibited a reasonable improvement of hepatic antioxidant enzymes. Moreover, serum and liver content of nitric oxide (NO) were markedly decreased in this model (26 and 25%, respectively), and were almost normalized following quercetin administration.These data revealed that quercetin has the ability to ameliorate HCD-induced lipemic-oxidative injury in rat liver possibly through its antioxidant potential and/or increased NO bioavailability.

The dietary flavonoids, especially their glycosides, are the most vital phytochemicals in diets and are of great general interest due to their diverse bioactivity. Almost all natural flavonoids exist as their O-glycoside or C-glycoside forms in plants. The dietary flavonoid C-glycosides have received less attention than their corresponding O-glycosides. This review summarizes current knowledge regarding flavonoid C-glycosides and their influence on human health. Among the flavonoid C-glycosides, flavone C-glycosides, especially vitexin, isoorientin, orientin, isovitexin and their multiglycosides are more frequently mentioned than others. Flavonoid C-monoglycosides are poorly absorbed in human beings with very few metabolites in urine and blood and are deglycosylated and degraded by human intestinal bacteria in colon. However, flavonoid C-multiglycosides are absorbed unchanged in the intestine and distributed to other tissues. Flavonoid C-glycosides showed significant antioxidant activity, anticancer and antitumor activity, hepatoprotective activity, anti-inflammatory activity, anti-diabetes activity, antiviral activity, antibacterial and antifungal activity, and other biological effects. It looks like that the C-glycosylflavonoids in most cases showed higher antioxidant and anti-diabetes potential than their corresponding O-glycosylflavonoids and aglycones. However, there is a lack of in vivo data on the biological benefits of flavonoid C-glycosides. It is necessary to investigate more on how flavonoid C-glycosides prevent and handle the diseases.