Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The flavonoid luteolin inhibits niacin-induced flush.

ABSTRACT: BACKGROUND AND PURPOSE: Sustained release niacin effectively lowers serum cholesterol, LDL and triglycerides, while raising HDL. However, 75% of patients experience cutaneous warmth and itching known as flush, leading to discontinuation. Acetylsalicylic acid (aspirin) reduces this flush only by about 30%, presumably through decreasing prostaglandin D2 (PGD2). We investigated whether niacin-induced flush in a rat model involves PGD2 and 5-HT, and the effect of certain flavonoids. EXPERIMENTAL APPROACH: Three skin temperature measurements from each ear were recorded with an infrared pyrometer for each time point immediately before i.p. injection with either niacin or a flavonoid. The temperature was then measured every 10 min for 60 min. KEY RESULTS: Niacin (7.5 mg per rat, equivalent to a human dose of 1750 mg per 80 kg) maximally increased ear temperature to 1.9+/-0.2 degrees C at 45 min. Quercetin and luteolin (4.3 mg per rat; 1000 mg per human), administered i.p. 45 min prior to niacin, inhibited the niacin effect by 96 and 88%, respectively. Aspirin (1.22 mg per rat; 325 mg per human) inhibited the niacin effect by only 30%. Niacin almost doubled plasma PGD2 and 5-HT, but aspirin reduced only PGD2 by 86%. In contrast, luteolin inhibited both plasma PGD2 and 5-HT levels by 100 and 67%, respectively. CONCLUSIONS AND IMPLICATIONS. Niacin-induced skin temperature increase is associated with PGD2 and 5-HT elevations in rats; luteolin may be a better inhibitor of niacin-induced flush because it blocks the rise in both mediators.

SUBMITTER: Papaliodis D

PROVIDER: S-EPMC2437911 | biostudies-other | 2008 Apr

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Luteolin, a natural flavonoid, inhibits methylglyoxal induced apoptosis via the mTOR/4E-BP1 signaling pathway.

Project description:Methylglyoxal (MG) accumulation has been observed in human cerebrospinal fluid and body tissues under hyperglycaemic conditions. Recent research has demonstrated that MG-induces neuronal cell apoptosis, which promotes the development of diabetic encephalopathy. Our previous animal study has shown that luteolin, a natural flavonoid, attenuates diabetes-associated cognitive dysfunction. To further explore the neuroprotective properties of luteolin, we investigated the inhibitive effect of luteolin on MG-induced apoptosis in PC12 neuronal cells. We found that MG inhibited cell viability in a dose-dependent manner and induced apoptosis in PC12 cells. Pretreatment with Luteolin significantly elevated cell viability, reduced MG-induced apoptosis, inhibited the activation of the mTOR/4E-BP1 signaling pathway, and decreased pro-apoptotic proteins, Bax, Cytochrome C as well as caspase-3. Furthermore, we found that pretreatment with the mTOR inhibitor, rapamycin, significantly reduced the expression of the pro-apoptotic protein Bax. Therefore, these observations unambiguously suggest that the inhibitive effect of Luteolin against MG-induced apoptosis in PC12 cells is associated with inhibition of the mTOR/4E-BP1 signaling pathway.

| S-EPMC5554232 | biostudies-literature

A Food-Derived Flavonoid Luteolin Protects against Angiotensin II-Induced Cardiac Remodeling.

Project description:Oxidative stress has been implicated in cardiac remodeling (cardiac fibrosis and hypertrophy), which impairs cardiac function and metabolism; therefore, it is anticipated antioxidative compounds will have protective properties against cardiac remodeling. Luteolin (3',4',5,7-tetrahydroxyflavone), a widely distributed flavonoid found in many herbal extracts including celery, green pepper, perilla leaves and seeds, and chamomile, is a known to be a potent antioxidant and was previously demonstrated to exert an antifibrotic effect in the lungs and the liver. In this study, we clearly demonstrate that oral pretreatment with the higher-luteolin diet (0.035% (wt/wt)) protected against cardiac fibrosis and hypertrophy as well as a hyperoxidative state in Ang II-infused rats. In cardiac tissue, increased gene expression levels of TGFβ1, CTGF, Nox2, Nox4, ANP, and BNP induced by Ang II were restored by oral pretreatment of this high-luteolin diet. In cultured rat cardiac fibroblasts, H2O2-induced TGFβ1 expression and the phosphorylation of JNK were suppressed by luteolin pretreatment. In conclusion, food-derived luteolin has protective actions against Ang II-induced cardiac remodeling, which could be mediated through attenuation of oxidative stress.

| S-EPMC4556625 | biostudies-literature

The Dietary Flavonoid, Luteolin, Negatively Affects Neuronal Differentiation.

Project description: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.

| S-EPMC6418693 | biostudies-literature

The flavonoid luteolin, but not luteolin-7-O-glucoside, prevents a transthyretin mediated toxic response.

Project description:Transthyretin (TTR) is a homotetrameric plasma protein with amyloidogenic properties that has been linked to the development of familial amyloidotic polyneuropathy (FAP), familial amyloidotic cardiomyopathy, and senile systemic amyloidosis. The in vivo role of TTR is associated with transport of thyroxine hormone T4 and retinol-binding protein. Loss of the tetrameric integrity of TTR is a rate-limiting step in the process of TTR amyloid formation, and ligands with the ability to bind within the thyroxin binding site (TBS) can stabilize the tetramer, a feature that is currently used as a therapeutic approach for FAP. Several different flavonoids have recently been identified that impair amyloid formation. The flavonoid luteolin shows therapeutic potential with low incidence of unwanted side effects. In this work, we show that luteolin effectively attenuates the cytotoxic response to TTR in cultured neuronal cells and rescues the phenotype of a Drosophila melanogaster model of FAP. The plant-derived luteolin analogue cynaroside has a glucoside group in position 7 of the flavone A-ring and as opposed to luteolin is unable to stabilize TTR tetramers and thus prevents a cytotoxic effect. We generated high-resolution crystal-structures of both TTR wild type and the amyloidogenic mutant V30M in complex with luteolin. The results show that the A-ring of luteolin, in contrast to what was previously suggested, is buried within the TBS, consequently explaining the lack of activity from cynaroside. The flavonoids represent an interesting group of drug candidates for TTR amyloidosis. The present investigation shows the potential of luteolin as a stabilizer of TTR in vivo. We also show an alternative orientation of luteolin within the TBS which could represent a general mode of binding of flavonoids to TTR and is of importance concerning the future design of tetramer stabilizing drugs.

| S-EPMC4447256 | biostudies-literature

Endocrine disrupting activities of the flavonoid nutraceuticals luteolin and quercetin.

Project description:Dietary plant flavonoids have been proposed to contribute to cancer prevention, neuroprotection, and cardiovascular health through their anti-oxidant, anti-inflammatory, pro-apoptotic, and antiproliferative activities. As a consequence, flavonoid supplements are aggressively marketed by the nutraceutical industry for many purposes, including pediatric applications, despite inadequate understanding of their value and drawbacks. We show that two flavonoids, luteolin and quercetin, are promiscuous endocrine disruptors. These flavonoids display progesterone antagonist activity beneficial in a breast cancer model but deleterious in an endometrial cancer model. Concurrently, luteolin possesses potent estrogen agonist activity while quercetin is considerably less effective. These results highlight the promise and peril of flavonoid nutraceuticals and suggest caution in supplementation beyond levels attained in a healthy, plant-rich diet.

| S-EPMC3851288 | biostudies-literature

Luteolin, an emerging anti-cancer flavonoid, poisons eukaryotic DNA topoisomerase I.

Project description:Luteolin, a naturally occurring flavonoid, is abundant in our daily dietary intake. It exhibits a wide spectrum of pharmacological properties, but little is known about its biochemical targets other than the fact that it induces topoisomerase II-mediated apoptosis. In the present study, we show that luteolin completely inhibits the catalytic activity of eukaryotic DNA topoisomerase I at a concentration of 40 microM, with an IC50 of 5 microM. Preincubation of enzyme with luteolin before adding a DNA substrate increases the inhibition of the catalytic activity (IC50=0.66 microM). Treatment of DNA with luteolin before addition of topoisomerase I reduces this inhibitory effect. Subsequent fluorescence tests show that luteolin not only interacts directly with the enzyme but also with the substrate DNA, and intercalates at a very high concentration (>250 microM) without binding to the minor groove. Direct interaction between luteolin and DNA does not affect the assembly of the enzyme-DNA complex, as evident from the electrophoretic mobility-shift assays. Here we show that the inhibition of topoisomerase I by luteolin is due to the stabilization of topoisomerase-I DNA-cleavable complexes. Hence, luteolin is similar to camptothecin, a class I inhibitor, with respect to its ability to form the topoisomerase I-mediated 'cleavable complex'. But, unlike camptothecin, luteolin interacts with both free enzyme and substrate DNA. The inhibitory effect of luteolin is translated into concanavalin A-stimulated mouse splenocytes, with the compound inducing SDS-K+-precipitable DNA-topoisomerase complexes. This is the first report on luteolin as an inhibitor of the catalytic activity of topoisomerase I, and our results further support its therapeutic potential as a lead anti-cancer compound that poisons topoisomerases.

| S-EPMC1222798 | biostudies-other

The flavonoid luteolin inhibits Fc?-dependent respiratory burst in granulocytes, but not skin blistering in a new model of pemphigoid in adult mice.

Project description:Bullous pemphigoid is an autoimmune blistering skin disease associated with autoantibodies against the dermal-epidermal junction. Passive transfer of antibodies against BP180/collagen (C) XVII, a major hemidesmosomal pemphigoid antigen, into neonatal mice results in dermal-epidermal separation upon applying gentle pressure to their skin, but not in spontaneous skin blistering. In addition, this neonatal mouse model precludes treatment and observation of diseased animals beyond 2-3 days. Therefore, in the present study we have developed a new disease model in mice reproducing the spontaneous blistering and the chronic course characteristic of the human condition. Adult mice were pre-immunized with rabbit IgG followed by injection of BP180/CXVII rabbit IgG. Mice pre-immunized against rabbit IgG and injected 6 times every second day with the BP180/CXVII-specific antibodies (n?=?35) developed spontaneous sustained blistering of the skin, while mice pre-immunized and then treated with normal rabbit IgG (n?=?5) did not. Blistering was associated with IgG and complement C3 deposits at the epidermal basement membrane and recruitment of inflammatory cells, and was partly dependent on Ly-6G-positive cells. We further used this new experimental model to investigate the therapeutic potential of luteolin, a plant flavonoid with potent anti-inflammatory and anti-oxidative properties and good safety profile, in experimental BP. Luteolin inhibited the Fc?-dependent respiratory burst in immune complex-stimulated granulocytes and the autoantibody-induced dermal-epidermal separation in skin cryosections, but was not effective in suppressing the skin blistering in vivo. These studies establish a robust animal model that will be a useful tool for dissecting the mechanisms of blister formation and will facilitate the development of more effective therapeutic strategies for managing pemphigoid diseases.

| S-EPMC3273480 | biostudies-literature

Anxiolytic effects of the flavonoid luteolin in a mouse model of acute colitis.

Project description:Anxiety related disorders commonly occur in association with major depressive disorder (MDD) in individuals suffering from peripheral inflammation, with a higher prevalence among IBS patients. We have previously shown that the bioflavonoid luteolin has pronounced analgesic and antidepressant-like effects in mice with dextran sodium sulfate (DSS)-induced colitis. Here, we further evaluate the biological effect of luteolin as a possible anxiolytic agent in DSS treated mice. Anxiolytic action was evaluated using the open field test (OF), the novelty suppressed feeding test (NSFT) and the elevated plus maze test (EPM). Luteolin increased the number of crossings in the center of the OF apparatus, reduced the latency to interact with the food pellet in the NSFT, and increased the time spent in the open arms in the EPM. These results suggest luteolin as a possible natural anxiolytic molecule without sedative effects, thus reinforcing its therapeutic potential for the comorbidities involving peripheral inflammation, pain, mood and anxiety-related disorders.

| S-EPMC6933648 | biostudies-literature

Luteolin: A Flavonoid that Has Multiple Cardio-Protective Effects and Its Molecular Mechanisms.

Project description:Cardiovascular disease (CVD) has become the leading cause of morbidity and mortality worldwide. A well-monitored diet with a sufficient intake of fruits and vegetables has been confirmed as a primary prevention of CVD. Plant constituents such as flavonoids have been shown to confer healthy benefits. Luteolin (Lut), a kind of flavonoid, possesses anti-oxidative, anti-tumor, and anti-inflammatory properties. Recent scientific literature has reported the cardiac protective effects of Lut in vitro and in vivo. Therefore, the aim of this review is to provide an update and detailed overview with cardio-protective molecular mechanisms of Lut with a focus on multiple intrinsic and extrinsic effectors. We further explore how these mechanisms participate in ischemia/reperfusion (I/R) injury, heart failure (HF) and atherosclerosis (AS). A proper understanding of the cardiovascular protective effects and the relative mechanisms of Lut may provide the possibility of new drug design and development for CVD. With the previous studies mainly focused on basic research, we need to advance the prospects of its further clinical utilization against CVD, large prospective clinical trials of Lut are needed to observe its therapeutic effects on patients with I/R injury, HF and AS, especially on the effective therapeutic dosage, and safety of long-term administration.

| S-EPMC5635727 | biostudies-literature

Apolipoprotein E3 Containing Nanodiscs as Vehicles for Transport and Targeted Delivery of Flavonoid Luteolin

Project description: Not available

| S-EPMC10795050 | biostudies-literature