Showing posts sorted by relevance for query quercetin. Sort by date Show all posts
Showing posts sorted by relevance for query quercetin. Sort by date Show all posts

Tuesday, January 19, 2010

Quercetin blocks Hepatitis C infection....

The conventional treatments for hepatitis C are interferon and ribavirin, which can cause major side effects and aren't effective in all patients. But something interesting and unique has been achieved  by UCLA researchers.

As per the claim by the lead researcher Samuel French Assistant Professor, Pathology of UCLA, they have  identified major two cellular proteins (HSPs, heat shock proteins 40 and 70) that play an important role in hepatitis C infection, and they say the finding may point to new and less toxic treatments for the disease, which can lead to cirrhosis and liver cancer. The researchers also found that Quercetin,  blocks the synthesis of two heat shock proteins 40 and 70proteins  and significantly inhibited viral infection in tissue culture.


 
Quercetin (see the structure) :  

Is a plant-derived flavonoid, specifically a flavonol, used as a nutritional supplement. Laboratory studies show it may have anti-inflammatory and antioxidant properties,  and it is being investigated for a wide range of potential health benefits.Interestingly American cancer society, says that while quercetin has been promoted as being effective against a wide variety of diseases, including cancer, There is current early-stage clinical research on quercetin addressing safety and efficacy against sarcoidosis, asthma and glucose absorption in obesity and diabetes. Food riches in Quercetin includes, capers, lovage, apples, tea (Camellia sinensis), onion, especially red onion (higher concentrations of quercetin occur in the outermost rings), red grapes, citrus fruit, tomato, broccoli and other leafy green vegetables, cherries and berries.


Significant claims by the researchers are ;


a. quercetin targets cellular proteins rather than viral proteins, there is less likelihood of developing viral
    resistance (cellular proteins cannot change like viral proteins can);
b. quercetin may allow for the dissection of the viral life cycle and has potential therapeutic use to reduce
    virus  production with low associated toxicity.

Hope the researcher will have positive results from the phase 1 clinical trial.....

Ref :http://www.cancer.ucla.edu/Index.aspx?page=644&recordid=312

Saturday, June 27, 2020

Study: Antioxidant flavonol linked to lower risk of Alzheimer's dementia


In continuation of my update on kaempferol, myricetin and  quercetin


Kaempferol.png 

                                                                 kaempferol

Skeletal formula of myricetin

                                                                       

                                                                      myricetin

                                                 

                                                                          Quercetin

        

People who eat or drink more foods with the antioxidant flavonol, which is found in nearly all fruits and vegetables as well as tea, may be less likely to develop Alzheimer's dementia years later, according to a study published in the January 29, 2020, online issue of Neurology, the medical journal of the American Academy of Neurology.

"More research is needed to confirm these results, but these are promising findings," said study author Thomas M. Holland, MD, of Rush University in Chicago. "Eating more fruits and vegetables and drinking more tea could be a fairly inexpensive and easy way for people to help stave off Alzheimer's . With the  increasing worldwide, any decrease in the number of people with this devastating disease, or even delaying it for a few years, could have an enormous benefit on ."
Flavonols are a type of flavonoid, a group of phytochemicals found in plant pigments known for its beneficial effects on health.
The study involved 921 people with an average age of 81 who did not have Alzheimer's dementia. The people filled out a questionnaire each year on how often they ate certain foods. They were also asked about other factors, such as their level of education, how much time they spent doing  and how much time they spent doing mentally engaging activities such as reading and playing games.
The people were tested yearly to see if they had developed Alzheimer's dementia. They were followed for an average of six years. The researchers used various tests to determine that 220 people developed Alzheimer's dementia during the study.
The people were divided into five groups based on how much flavonol they had in their diet. The average amount of flavonol intake in US adults is about 16 to 20 milligrams per day. In the study, the lowest group had intake of about 5.3 mg per day and the highest group consumed an average of 15.3 mg per day.
The study found that people in the highest group were 48 percent less likely to later develop Alzheimer's dementia than the people in the lowest group after adjusting for genetic predisposition and demographic and lifestyle factors. Of the 186 people in the highest group, 28 people, or 15 percent, developed Alzheimer's dementia, compared to 54 people, or 30 percent, of the 182 people in the lowest group.
The results were the same after researchers adjusted for other factors that could affect the risk of Alzheimer's dementia, such as, diabetes, previous heart attack, stroke and high blood pressure.
The study also broke the flavonols down into four types: isorhamnetin, kaempferol, myricetin and quercetin. The top food contributors for each category were: pears, olive oil, wine and tomato sauce for isorhamnetin; kale, beans, tea, spinach and broccoli for kaempferol; tea, wine, kale, oranges and tomatoes for myricetin; and tomatoes, kale, apples and tea for quercetin.
People who had high intake of isorhamnetin were 38 percent less likely to develop Alzheimer's. Those with high intake of kaempferol were 51 percent less likely to develop dementia. And those with high intake of myricetin were also 38 percent less likely to develop dementia. Quercetin was not tied to a lower risk of Alzheimer's dementia.
Holland noted that the study shows an association between dietary flavonols and Alzheimer's risk but does not prove that flavonols directly cause a reduction in disease risk.
Other limitations of the study are that the food frequency questionnaire, although valid, was self-reported, so people may not accurately remember what they eat, and the majority of participants were white people, so the results may not reflect the general population.
https://en.wikipedia.org/wiki/Myricetin
https://en.wikipedia.org/wiki/Quercetin
https://medicalxpress.com/news/2019-07-high-hemoglobin-linked-dementia.html

Thursday, August 12, 2010

ProstaCaid (33-ingredient comprehensive polyherbal preparation) against prostate cancer......

We have seen  many benefits of natural products rich in  Quercetin,   Epigallocatechin gallate (EGCG) and many other polyphenol antioxidant from natural products like green tea, broccoli peaches and plums. Interestingly, now researchers from  Columbia University have come up with an interesting finding, i.e., ProstaCaid is a 33-ingredient comprehensive polyherbal preparation with supplements of vitamin C, vitamin D3, zinc, selenium, quercitin, 3,3′-diinodolymethane (DIM), and lycopene was able to stop abnormal cell growth and induce apoptosis (programmed cell death) in both hormone sensitive and hormone resistant prostate cancer cell lines at unusually low concentrations, which makes the findings more significant...

Herbal extracts include the extracts from turmeric root, saw palmetto berry, grape skin, pomegranate, pumpkin seed, pygeum bark, sarsaparilla root, green tea, and Japanese knotweed. Hence, it is rich in natural polyphenols, including quercetin, resveratrol, epigallocatechin gallate (EGCG), and ellagic acid, which have previously demonstrated anticancer potential. The unique formula contains 3 medicinal mushrooms grown on an herbal-enhanced medium. The mushrooms included are Phellinus linteus, Ganoderma lucidum, and Coriolus versicolor, each with known anticancer properties.

Researchers claim that, ProstaCaid was designed based on constituents that exhibit antiprolifetaive, antioxidant, and apoptotic activities; however, its efficacy and the mechanisms of action are yet to be examined. Researchers looked at the effectiveness of the preparation in suppressing several types of prostate cancer cell lines in culture and attempt to delineate the mechanism of action for justification in pursuing animal to determine efficicacy invivo.

Researchers conclude that, the anticancer activity of ProstaCaid may be ascribed to its polyphenolic flavonoids and curcuminoids derived from various herbs as well as other supplements, such as DIM. The preparation contains supplements such as quercetin (15%), Curcuma longa root extract complex with enhanced bioavailability (BCM-95; 20%), DIM (3%), and resveratrol (0.2%). Some of these components have shown a strong doseand time-dependent growth inhibition and apoptotic death in prostate cancer cells; 25 mM of quercetin inhibited about 50% PC3 cell growth for 72 hours. At 24 hours, 50 mM and 100 mM quercetin induced G2/M arrest and apoptosis, manifested by the decrease in G2/M-related protiens.

Researchers summarise  that,    ProstaCaid has anti-cancer activities in both AD and AI prostate cancer cells at very low concentrations (25 mg/mL). It also suggests that ProstaCaid inhibits cell growth and survival, at least through the inhibition of AKT and MAPK signaling. The effect on AI cell lines is especially of importance as there is presently no curative therapy for hormone refractory prostate cancer.

Researchers postulate that ProstaCaid may affect activity of Cdc2/cyclin B1 kinase by reducing this complex formation. Cdc2 could be dephosphorylated by Cdc25C and become inactive or be phosphorylated by protein kinase, such as Wee1, and then converted into an inactive form. They also suggest that more studies are needed in the future to test it and to define its upstream events in PC3 cells.

Ref : Jun Yan and Aaron E. Katz, Integr Cancer Ther 2010 9: 186

Saturday, February 6, 2010

7,8-Dihydroxyflavone (a selective TrkB agonist) as new class of brain protecting drugs ?

In recent days, I have seen many groups working on the diverse activities of  flavonoid family of chemicals. In my earlier blog, have mentioned about Quercetin   (quercetin a flavonoid has been reported for diverse activities). Now interestingly  investigators at Emory University School of Medicine,  have reported that '7,8-Dihydroxyflavone' (see structure - also a  member of the flavonoid family of chemicals, abundant in fruits and vegetables-cherries to soybeans)   can partially prevent the death of neurons in experimental models of three neurological diseases" and  this  selective effect suggest that it could be  a new class of brain-protecting drugs.

Investigators at Emory University School of Medicine, led by Dr. Keqiang Ye, (Associate professor of pathology and laboratory medicine), were searching for a way to mimic a protein found in the brain called BDNF (brain-derived neurotrophic factor).

BDNF has been studied extensively for its ability to protect neurons vulnerable to degeneration in several diseases, such as ALS, Parkinson's and Alzheimer's disease,  Ye, one of the authors says, "the trouble with BDNF is one of delivery. It's a protein, so it can't cross the blood-brain barrier and degrades quickly". 

Researchers tried a a library of chemicals to find those that could stimulate one of the proteins on the surfaces of neurons that BDNF binds to. They could show that, 7,8-dihydroxyflavone sends survival signals to brain cells by pulling together two TrkB receiver-dish molecules, just like BDNF does. Interesting part of this research is that, 7,8-Dihydroxyflavone is active in the brain when injected into the body cavity (meaning that it can cross the blood-brain barrier). As claimed by the co-author Ye, many experimental "neuroprotectant" drugs have been unsuccessful in clinical trials for diseases such as stroke and Parkinson's over the last decade and 7,8-Dihydroxyflavone is the first molecule that specifically triggers TrkB. To show the effects of 7,8-dihydroxyflavone depended on TrkB,  authors used mice with a modified TrkB gene and were successful in doing so. Detailed animal studies to substantiate the claim  are essential , still  in my opinion its a good achievement... (details...)

Monday, May 28, 2012

Flavonoid Compound Found in Foods and Supplements May Prevent the Formation of Blood Clots, Study Suggests...

A compound called  rutin (see structure - a quercetin derivative), commonly found in fruits and vegetables and sold over the counter a dietary supplement, has been shown to inhibit the formation of blood clots in an animal model of thrombosis.

 As per the researchers claim,
"Approximately half of all morbidity and mortality in the United States can be attributed to heart attack or stroke."..

The study focused on protein disulfide isomerase (PDI) which is found in all cells. Investigators in BIDMC's Division of Hemostasis and Thrombosis had previously shown that PDI is rapidly secreted from both platelets and endothelial cells during thrombosis, when a clot forms in a blood vessel, and that inhibition of PDI could block thrombosis in a mouse model.

"This was a transformative and unanticipated finding because it identified, for the first time, that PDI is secreted from cells in a live animal and is a potential target for preventing thrombosis," says Flaumenhaft. However, because intracellular PDI is necessary for the proper synthesis of proteins, the scientists had to identify a specific compound that could block the thrombosis-causing extracellular PDI -- without inhibiting the intracellular PDI.
They began by conducting a high-throughput screen of a wide array of compounds to identify PDI inhibitors. Among the more than 5,000 compounds that were screened, quercetin-3-rutinoside (rutin) emerged as the most potent agent. "Rutin was essentially the champion compound," says Flaumenhaft.

A bioflavonoid that is naturally found in many fruits, vegetables and teas including onions, apples and citrus fruits, rutin is also sold as an herbal supplement, having received a special designation for safety from the U.S. Food and Drug Administration (FDA). Surprisingly, studies of the rutin molecule demonstrated that the same part of the molecule that provides rutin with its ability to inhibit PDI also prevents the compound from entering cells."That finding explained how this compound can be both a potent inhibitor of PDI and a safe food supplement," says Flaumenhaft. "Our next questions were, 'Is this compound anti-thrombotic? Can it prevent blood clots?'"

Monday, January 25, 2010

Apple pectin as a novel prebiotic substance, that helps the intestinal microbiota....

We know the proverb "An apple a day keeps the doctor away" because of the fact that apple has been  addressing the health effects of the fruit, dates from 19th century. Interestingly apples have shown reduce the risk of  colon cancer, prostate cancer and lung cancer.Compared to many other fruits and vegetables, apples contain relatively low amounts of Vitamin C, but are rich source of other antioxidants.  The fiber content, while less than in most other fruits, helps regulate bowel movements and may thus reduce the risk of colon cancer. They may also help with heart disease, weight loss,  and controlling cholesterol, as they do not have any cholesterol, have fiber, which reduces cholesterol by preventing re absorption, and are bulky for their caloric content like most fruits and vegetables . There is  in vitro evidence that  phenolic compounds in apples (quercetin, epicatechin, and procyanidin B2) are  cancer-protective and  also demonstrate antioxidant activity.

Apples can be canned or juiced and the juice can be fermented to make apple cider (non-alcoholic, sweet cider) and cider (alcoholic, hard cider), ciderkin, and vinegar. Alcoholic beverages are produced such as applejack (beverage) and Calvados.  Apple wine can also be made. Pectin is also produced. 

Now microbiologists at the University of Denmark's National Food Institute,  tested the effect of apple consumption by feeding rats a diet of whole apples as well as apple-derived products such as apple juice and puree. The researchers then checked the bacteria in the guts of the rats to see if consuming apples affected levels of "friendly" bacteria, which are beneficial for digestive health and may reduce the risk of some diseases. Researchers found that rats eating a diet high in pectin, a component of dietary fiber in apples, had increased amounts of certain bacteria that may improve intestinal health.

As per the claim by the researchers, consuming apples affected levels of "friendly" bacteria, (bacteria that are beneficial for digestive health) and there by  reduce the risk of some diseases. And bacteria help produce short-chain fatty acids that provide ideal pH conditions for ensuring a beneficial balance of microorganisms. They also produce butyrate, which is an important fuel for the cells of the intestinal wall. Interestingly, consumption of apple pectin (7% in the diet) increases the population of butyrate and beta-glucuronidase producing Clostridiales, and decreases the population of specific species within the Bacteroidetes group in the rat gut. Similar changes were not caused by consumption of whole apples, apple juice, puree or pomace....

Ref : http://www.biomedcentral.com/content/pdf/1471-2180-10-13.pdf

Wednesday, July 8, 2020

Plant flavonols significantly reduce Alzheimer’s risk

A new study published in the journal Neurology in January 2020 concludes that increasing the intake of plant flavonols steeply reduces the risk of Alzheimer’s dementia (AD) by up to a half. In other words, AD could be prevented in many people simply by regularly eating and drinking more foods containing these compounds such as tea, oranges, and broccoli.

Alzheimer’s disease

AD is a progressive brain disorder in which the individual loses cognitive skills, including memory and thinking skills, and the ability to perform simple tasks. It is by far the leading cause of such disorders and affects over 5 million Americans.
One study was carried out on over 900 people, who were part of a community-wide ongoing larger research project called the Rush Memory and Aging (MAP) Project. These participants were assessed yearly for their neurologic health and dietary patterns, for an average of 6 years, but some for as long as 12 years. The average age was 81 years, and 3 out of 4 were female.

The findings

In the first study, 220/921 participants developed AD during the study. The risk of AD fell with a greater intake of flavonols. This finding held good even after the researchers adjusted for other health-associated factors – because those with the highest total flavonol intake were also the best educated, most active and took part in more cognitive activities. They also accounted for genetic factors like the presence of the APOE4 gene, and for cardiovascular risk factors that could influence the risk of AD, such as diabetes mellitus, history of heart attack, or stroke, or hypertension.
When classified into five groups based on decreasing flavonol intake, the participants in the first group (highest intake) consumed over 15 mg of flavonols a day. Compared to those in the lowest fifth (about 5 mg a day), these individuals showed an approximately 50% reduction in AD risk.
In concrete terms, 28 of 186 patients in the highest-intake group developed AD, vs. 54 of 182 in the lowest-intake group.
With respect to individual flavonols, kaempferol intake was linked to a reduction of almost 50%, and both myricetin and isorhamnetin by 40% each. A fourth flavonol, called quercetin, had no noticeable effect on AD risk.
Participants with the highest flavonol intake drank about one cup of black tea a day. Kale, and about a glass of red wine each day, could also supply flavonols.

Sources of flavonols

Kaempferol is richly present in green leafy vegetables, including spinach, broccoli, beans, tea and kale – and also in tea. Isorhamnetin-rich foods include olive oil, red wine, pears and tomato sauce. Myricetin is found in tea, kale, oranges, tomatoes and red wine.
Researcher Thomas Holland says, “More research is needed to confirm these results, but these are promising findings. Eating more fruits and vegetables and drinking more tea could be a fairly inexpensive and easy way for people to help stave off Alzheimer's dementia.”

Implications

Many scientists disagree with the emphasis on flavonols. Though these were thought to have antioxidant activity in the body, this theory was discredited many decades earlier. Antioxidant activity ceases when they are ingested and subjected to the activity of enzymes in the digestive tract.
They point out that flavonols are found in many plants, fruits and vegetables, which have been associated with good health for centuries. Nutritionists say that the AD-delaying effects of such foods are likely due to other plant chemicals which are relatively more abundant. On the other hand, taking flavonol pills or tea extracts is unlikely to produce the same healthful effect, and overdoses could be counterproductive.
This is not to say that eating more flavonol-rich foods or drinking a cup of black tea in the morning would hurt, since any foods containing these chemicals would also contain many more healthful compounds including vitamins, minerals and plant fiber. Holland makes a valid point with his conclusion: “'With the elderly population increasing worldwide, any decrease in the number of people with this devastating disease, or even delaying it for a few years, could have an enormous benefit on public health.”
https://n.neurology.org/content/early/2020/01/29/WNL.0000000000008981

Wednesday, July 19, 2017

Animal studies examine role of raspberry products in weight management and motor function

Image result for red raspberries Image result for red raspberries


The latest issue of the Journal of Berry Research includes two new animal studies that investigate the effects of raspberry consumption in helping to support healthy weight and motor function (strength, balance and coordination). Future studies are needed to support the results found in these studies.

One-cup of frozen red raspberries has only 80 calories, is an excellent source of vitamin C, and provides nine grams of fiber (more fiber than any other berry). Like most berries, raspberries are a low-glycemic index food. Raspberries contain phytochemicals, such as ellagic acid, quercetin, gallic acid, cyanidins, pelargonidins, catechins, kaempferol and salicylic acid.

Animal and cellular studies examining how phytochemicals may work at the molecular level suggest that certain phytochemicals may help slow age-related declines. Age is the number one risk factor for many chronic diseases. Likewise, obesity is a major risk factor for chronic disease. These latest animal studies examine two important areas of health where raspberry products may play a role in weight management and also support motor function.

OBESITY

An animal study conducted by researchers at Oregon State University found that when added to a high-fat, high-sucrose diet, raspberry products and raspberry phytochemicals were found to significantly decrease weight gain associated with a high-fat, high calorie diet. Raspberry juice and raspberry puree concentrates were provided at 10% of total energy (the equivalent of 200 calories in a 2,000 calorie diet), and a combination of ellagic acid and raspberry ketone were provided at 0.2% weight/weight.

In the study, 76 male mice were divided into the following diets: a low-fat control group (10% calories from fat), a high-fat control group (45% calories from fat) and seven "high-fat treatment" groups that included a high-fat diet plus either raspberry juice concentrate, raspberry puree concentrate, raspberry fruit powder, raspberry seed extract, raspberry ketone and a combination of equal parts of ellagic acid and raspberry ketone.

"The addition of raspberry juice concentrate, raspberry puree concentrate and the combination of ellagic acid plus raspberry ketones to the high fat diet significantly reduced weight gain observed in the high-fat fed mice," said Dr. Neil Shay, Principal Investigator. "In the case of the high-fat and raspberry juice concentrate diet, weight gain was reduced to a level that was statistically equivalent to the weight gain of the low-fat fed mice, despite the fact that all high-fat fed groups consumed the same amount of calories and more energy than the low-fat control group throughout the study."

The researchers concluded that the intake of a reasonable level of some raspberry food products may influence some of the metabolic consequences of consuming a high-fat, high-calorie diet in the development of obesity in male mice.

"We hope that the findings from this study can help guide the design of future clinical trials," said Dr. Shay.

MOTOR FUNCTION

Researchers from the Human Nutrition Research Center on Aging at Tufts University evaluated the effectiveness of a red raspberry-supplemented diet on age-sensitive measures of learning, memory and motor performance in older rats.

In this 10-week study, red raspberry supplementation was found to significantly improve motor skills. Specifically, compared to rats fed a standard well-balanced diet, rats fed a diet supplemented with freeze-dried raspberry extract performed better on tests which measured psychomotor coordination and balance, as well as tests that measure muscle tone, strength, and stamina.

"These results may have important implications for healthy aging," said lead researcher Barbara Shukitt-Hale, PhD. "While further research in humans is necessary, animal model studies are helpful in identifying deficits associated with normal aging."