Flavonoids Help Prevent Leukemia Cell Development
Filed Under News January 4, 2009
An extract from grape seeds forces laboratory leukemia cells to commit cell suicide, according to researchers from the University of Kentucky. They found that within 24 hours, 76 percent of leukemia cells had died after being exposed to the extract.
“These results could have implications for the incorporation of agents such as grape seed extract into prevention or treatment of hematological malignancies and possibly other cancers,” said the study’s lead author, Xianglin Shi, Ph.D., professor in the Graduate Center for Toxicology at the University of Kentucky.
“What everyone seeks is an agent that has an effect on cancer cells but leaves normal cells alone, and this shows that grape seed extract fits into this category,” he said.
Shi adds, however, that the research is not far enough along to suggest that people should eat grapes, grape seeds, or grape skin in excess to stave off cancer. “This is very promising research, but it is too early to say this is chemo-protective.”
Hematological cancers – leukemia, lymphoma and myeloma – accounted for an estimated 118,310 new cancer cases and almost 54,000 deaths in 2006, ranking these cancers as the fourth leading cause of cancer incidence and death in the U.S.
Given that epidemiological evidence shows that eating vegetables and fruits helps prevent cancer development, Shi and his colleagues have been studying chemicals known as proanthocyanidins in fruits that contribute to this effect. Shi has found that apple peel extract contains these flavonoids, which have antioxidant activity, and which cause apoptosis in several cancer cell lines but not in normal cells. Based on those studies, and findings from other researchers that grape seed extract reduces breast tumors in rats and skin tumors in mice, they looked at the effect of the compound in leukemia cells.
Using a commercially available grape seed extract, Shi exposed leukemia cells to the extract in different doses and found the marked effect in causing apoptosis in these cells at one of the higher doses.
They also discovered that the extract does not affect normal cells, although they don’t know why.
The researchers then used pharmacologic and genetic approaches to determine how the extract induced apoptosis. They found that the extract strongly activated the JNK pathway, which then led to up-regulation of Cip/p21, which controls the cell cycle.
They checked this finding by using an agent that inhibited JNK, and found that the extract was ineffective. Using a genetic approach – silencing the JNK gene – also disarmed grape seed extract’s lethal attack in leukemia cells.
“This is a natural compound that appears to have relatively important properties,” Shi said.
Weather and Climate Affect Antioxidant Levels in Soybean Seeds
Filed Under News December 19, 2008
Agricultural Research Service (ARS) scientists have found that weather and climate play key roles in levels of a family of antioxidants in soybean seeds.
Lead plant physiologist Steven Britz of the ARS Food Components and Health Laboratory, part of the Beltsville Human Nutrition Research Center in Beltsville, Md., collaborated on the study with William Kenworthy with the University of Maryland in College Park.
The researchers found that weather and climate are significant factors affecting soybean seed tocopherol content. Tocopherols are a family of antioxidants that protect biological membranes. Among this family, alpha-tocopherol is the active form of vitamin E in humans.
Soybean seeds are a major source of vegetable oil in the U.S. diet, and consequently a major contributor to dietary tocopherol intake. The daily Recommended Dietary Allowance for vitamin E for men and women aged 14 and older is 15 milligrams. But more than 50 percent of American adults do not get adequate amounts of vitamin E, according to experts.
For the study, the researchers analyzed the content of tocopherols in soybean seeds grown at several locations in Maryland between 1999 and 2002. Weather was relatively normal between 1999 and 2001, but extreme drought and warmer temperatures characterized 2002.
Since soybeans mature at different rates, the researchers examined up to 18 soybean lines representing different maturity groups. There were small but significant increases in the proportion of alpha-tocopherol in beans from the same genetic line grown in warmer, full-season Eastern Shore locations compared to beans that matured under slightly cooler conditions.
But under extreme drought conditions in 2002, early maturing lines had as much as a 3.5-fold increase in relative alpha-tocopherol content, compared to the other years during which rainfall was adequate.
The field studies showed how nutritional properties of crops can be dramatically affected by weather and potentially by global environmental change, according to the authors.
Study Finds Strawberry Flavonoids May Reduce Risk of Heart Disease
Filed Under News December 17, 2008
A recent study from the University of California, Davis and the Illinois Institute of Technology found that strawberries may reduce the risk of heart disease. The popular fruit is rich in flavonoids, important compounds that may improve function of the endothelium — the cells that line the inside of blood vessels through the entire circulatory system.
In the study, researchers found that strawberries promote a healthy endothelium which supports a healthy cardiovascular system. The loss of proper endothelial function, or endothelial dysfunction, is very common in people with diabetes mellitus, hypertension and other chronic conditions that can increase the risk of heart disease.
For the study, a water-soluble extract of strawberry powder was applied to endothelial tissue in a laboratory model. The extract caused aortic vessels to relax through endothelial- nitric oxide- dependent pathways. The results suggest a beneficial role for strawberry in the management of blood pressure and heart disease risk.
Dr. Britt Burton-Freeman, Director of Nutrition at the National Center for Food Safety and Technology at the Illinois Institute of Technology and Assistant Research Nutritionist at the University of California, Davis has been involved in this and other studies regarding obesity and chronic disease research for more than 15 years. Her current research includes developing dietary strategies in conjunction with lifestyle changes for long-term treatment and management of obesity and related diseases, such as heart disease, diabetes and some cancers. She uses clinical, plant and basic science methodologies to study the effects of diet and dietary constituents on key processes contributing to healthy and pathogenic outcomes in humans.
In a recent presentation to members of the American Dietetic Association, Dr. Burton-Freeman said, “Strawberries contain a variety of bioactive compounds that can promote longevity and quality of life. For humans, these compounds can act as antioxidants, serve as anti-inflammatory agents, improve cell to cell communication, cause cancer cells to die, detoxify carcinogens — a number of benefits consistent with health and disease risk reduction.”
Blueberries May Reverse Memory Loss
Filed Under News December 3, 2008
Researchers at the University of Reading, found in tests, that adding blueberries to peoples diet consistently improved their memory.
They say flavonoid rich foods trigger the part of the brain which is responsible for memory and learning - meaning diets rich in fresh fruits may increase your memory capacity.
Dr Jeremy Spencer, from the department of food biosciences at the university, said: “Scientists have known of the potential health benefits of diets rich in fresh fruits for a long time.
“Our research provides scientific evidence to show that blueberries are good for you and supports the idea that a diet-based approach could potentially be used to increase memory capacity.
“We will be taking these findings to the next level by investigating the effects of diets rich in flavonoids on individuals suffering from cognitive impairment and possibly Alzheimer’s disease.”
The research has been published in the Free Radical Biology and Medicine journal.
Powdered Grapes Reduce Arthritis
Filed Under News December 1, 2008
Researchers at the Johns Hopkins University School of Medicine have shown that powdered grapes appear to reduce pain and inflammation in a rat model of arthritis, where rats’ knees are inflamed using a chemical injection.
Some rats were fed the powdered equivalent of 10 cups of grapes once a day after the arthritis-inducing injection, while others got only sugar water. Over the course of four days after the chemical injection, the researchers tested the rats’ inflammation levels and pain responses by measuring their sensitivity to mechanical stimulation such as prodding their paws and measuring the amount of knee swelling. Rats fed grape powder could withstand stronger prodding than their sugar-fed counterparts.
The researchers also compared the grape powder treatment with a common nonsteroidal anti-inflammatory drug, meloxicam, and found that while the dose of meloxicam alone was not sufficient to reduce pain, animals fed a combination of grape powder and meloxicam experienced even less pain from their arthritis than animals that received either substance alone. The combination treatment also reduced the knee swelling associated with inflammation.
“I think there are two important messages here,” says Jasenka Borzan, PhD, a research associate in anaesthesiology at Hopkins.
“That consuming flavonoids through natural products like grapes can be beneficial to health in general and also specifically for reducing inflammatory pain; and that consuming natural products like grapes may also be beneficial in reducing the amount of medication necessary to reduce inflammation.”
Quercetin Helps Beat Flu
Filed Under News November 13, 2008
In a recent study published in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, when researchers gave mice the flu virus along with a dose of quercetin, they were better able to fight off respiratory infection, especially when their immune systems were put to the test following a bout of stressful exercise. At the end of the 21 day trial, the quercetin-fed “stressed” mice were 27 percent more likely to be healthy, despite the exposure to the virus.
This study, from the University of South Carolina and Clemson University, supports previous findings that suggest including foods containing quercetin, which is a natural anti-histamine and anti-inflammatory compound, may be a natural way to help boost the immune system and help fight off infection.
Antioxidants Prevent Body Damage
Filed Under News November 9, 2008
Antioxidants are chemical compounds or substances that are thought to prevent cellular damage.
Antioxidants such as vitamin E, vitamin C, or beta carotene help remove, molecules called free radicals, from the body. These molecules are side products of damage done to the body by pollution and the natural aging process.
Free radicals in the body’s cells are unstable and tend to react negatively with other important molecules like DNA, causing malfunctions and injury on the cellular level. The destruction these free radicals produce may increase the risk of diseases such as heart disease, arthritis and cancer.
Antioxidants can also be beneficial in neutralizing bacteria and viruses.
Antioxidants Help Trauma Patients
Filed Under News October 23, 2008
Despite continuing improvements in overall delivery of care to critically injured patients, many trauma victims who survive their initial injury will often die of multiple-organ failure following an operation. In a study presented at the 2008 Clinical Congress of the American College of Surgeons (ACS), Bryan A. Cotton, MD, FACS, reported that “implementation of high-dose antioxidant protocol (vitamins C, E, and selenium) resulted in a reduction of pulmonary complications, in general, as well as infectious complications, including central line and catheter-related infections.”
Dr. Cotton, who is assistant professor of surgery at Vanderbilt University Medical Center, Nashville, TN, also observed a remarkable decrease in abdominal wall complications including abdominal compartment syndrome and surgical site infections. When an abdominal wound opens up, the result is not just an infection to be treated with antibiotics, he explained. The wounds need packing and some of them open up to the point where they have to be reconstructed with expensive agents.
“This is a high mortality, high morbidity, may-never-return-to-work-again problem in a young healthy patient,” he said. “Abdominal wall complications are enormous, yet we noted a reduction in some of these complications with implementation of antioxidants. Importantly, the biggest difference was in those patients who had a predicted mortality exceeding 50 percent.”
Immediately prior to completing this study, Dr. Cotton and his colleagues at Vanderbilt demonstrated that this same high-dose antioxidant protocol resulted in a stunning 28 percent reduction in mortality in acutely injured patients. In addition, patients’ length-of-stay in both the hospital and intensive care unit (ICU) were reduced. After the team observed the reduction in mortality after initiating the protocol, they wanted to learn exactly how antioxidants might work. It is all related to addressing the overwhelming oxidative stress, Dr. Cotton said.
He explained that any time a patient has an acute injury, an operation, or some kind of infection, it places a huge stress on the body. This stress can result in injured oxygen molecules called free radicals being released in the body. These molecules roam around, causing considerable damage at the cellular level. This damage is called oxidative stress.
Dr. Cotton said that past research by some renowned scientists in this field has shown a depletion in the store of antioxidants in critically stressed, critically injured patients. Essentially, it appears that antioxidants work as a team in mopping up some of the oxidative stress waste byproducts, reducing the stressors that cause harm.
As Dr. Cotton explains it, antioxidants are like an army of molecular warriors that rush to the site of an injury to fight infection. In the course of doing battle on the front lines, however, most troops are lost early on. When infectious insurgents rise up later on, patients are highly vulnerable to infections. Depletion of antioxidants is one of the mechanisms that explains why we are vulnerable. Antioxidant therapy replenishes those troops to help keep us safe.
“Antioxidant therapy is so simple and that’s what throws people off,” Dr. Cotton said, confessing that he had some doubts about it at first as well. Then he saw an impressive randomized prospective trial conducted by Avery B. Nathens, MD, MPH, which showed that some inflammatory states and responses were remarkably improved in patients who had received antioxidants versus those who did not. Dr. Nathens’ trial did not have enough patients in each arm of the study, though, so they were limited in their mortality conclusions.
“Based on these results, we were inspired to initiate a study with vitamins C and E. When we looked at the literature, however, there were some concurrent studies showing that selenium had an impact too, especially on sepsis and other infectious complications. So we combined all the existing research and did a cost analysis. When we learned it would cost only $11 a patient for a seven-day course of antioxidants, we decided to give it a try.”
This retrospective study followed a total of 4,279 patients admitted to the Vanderbilt University Medical Center trauma unit during the study period. High-dose antioxidant protocol was administered to all acutely injured patients (2,258 individuals) admitted to the center between October 1, 2005, and September 30, 2006. This treatment included 1,000 mg. vitamin C (ascorbic acid) and 1,000 IU vitamin E (DL - tocopherol acetate), each routinely given every eight hours by mouth, if the patient could take it that way. In addition, 200 mcg. selenium was given once daily intravenously. Patients received these supplements upon arrival, and they were continued for seven days or until discharge, whichever happened first. Patients who were pregnant or had serum creatinine levels >2.5mg/dL did not receive antioxidants.
A comparison cohort was made up of all patients (2,021 individuals) admitted to the trauma center between October 1, 2004, and September 30, 2005 prior to implementation of the antioxidant protocol. While pneumonia and renal failure were similar between the groups, the incidence of abdominal compartment syndrome was significantly less (90 versus 31), as were catheter-related infections (75 versus 50) and surgical site infections (101 versus 44). Pulmonary failure meaning the patient could not get off the ventilator was less as well (721 versus 528).
Dr. Cotton is now prescribing high-dose antioxidants only to the most seriously ill patients in the ICU, as they seem to derive the greatest benefit. He and his colleagues will now focus on dose adjustments and length of administration to see if the doses and duration they are currently using are optimal. They have been approached by several groups that are interested in collaborating and investigating these agents as part of multiinstitutional trials and expanding their use to critically ill nontrauma patients.
“While we are all looking for that magic bullet to cure some of the horrible things that can happen after someone is injured or has an operation, we have something at our disposal,” Dr. Cotton said. “It might not be that magic bullet, but it is a very inexpensive and safe way to reduce complications and mortality in the sickest patients.”
Assisting Dr. Cotton with this study were Aviram Giladi, BS; Bryan R. Collier, DO, FACS; Lesly A. Dossett, MD; and Sloan B. Fleming, PharmD, all from Vanderbilt. He received no funding for this research.
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Lycopene Said to Reduce Prostate Cancer Risk
Filed Under News October 8, 2008
Lycopene has been the subject of much research on plant chemicals that promote health. It is a carotenoid responsible for the red color in tomatoes and other fruits like watermelon and grape fruit. Carotenoids, along with phenolic acids and flavonoids, are all phytochemicals, the nutritionally-beneficial active compounds found in fruits and vegetables. Polyphenols, one of the potentially beneficial anti-cancer compounds, is also found in tomato products, predominantly in the skin and seeds.
A variety of epidemiological studies by Giovannucci in 2002; Mill in 1989 and Wu in 2004 have suggested that dietary factors may decrease the risk of prostate cancer. Increased consumption of tomatoes, carotenoids, vitamin C, selenium, cruciferous vegetables, polyphenools, soy, fish, green tea or Vitamin D may all be linked to a decreased risk of prostate cancer. Their studies further show that an increased consumption of fruits and vegetables significantly reduces the incidence of prostate cancer.
Lycopene and tomato products appear to reduce the risk of prostate cancer in epidemiogical studies. A study led by Giovannucci in 1995 showed that lycopene and tomato product intakes were associated with a decreased risk of prostate cancer. One study led by Gann in 1999 suggested a strong inverse association between aggressiveness of the cancer and plasma lycopene. Another study led by Wu in 2004 showed an inverse association between plasma lycopene concentrations and risk of prostate cancer although only in older men without a history of the disease.
Acai Berry Study
Filed Under News October 7, 2008
The study by a team of Texas AgriLife Research scientists, was published in a recent issue of the Journal of Agricultural and Food Chemistry.
The study involved 12 healthy volunteers who consumed a single serving of acai juice or pulp.
“Acai is naturally low in sugar, and the flavor is described as a mixture of red wine and chocolate,” said lead investigator Dr. Susanne Talcott.”
Talcott, who also is assistant professor with the Texas A&M University’s nutrition and food science department, said that previous studies have shown the ability of the human body to absorb target antioxidants (from other produce), but “no one had really tested to see if acai antioxidants are absorbed in humans.”
For the clinical trial, people were given acai pulp and acai juice containing half the concentration of anthocyanins as the pulp and each compared to the control foods: applesauce and a non-antioxidant beverage.
Blood and urine samples at 12 and 24 hours after consumption showed significant increases in antioxidant activity in the blood after both the acai pulp and applesauce consumption, she said. Both acai pulp and acai juice showed significant absorption of antioxidant anthocyanins into the blood and antioxidant effects.
Talcott and her co-researcher and husband Dr. Steve Talcott began studying the berry in 2001.
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