Vitamin A Compound Might Aid in Colon Cancer Fight

In continuation of my update on Retinoic acid

Retinoic acid, a compound derived in the body from vitamin A, might have a role in suppressing colon cancer, new animal research suggests.

"Retinoic acid has been known for years to be involved in suppressing inflammation in the intestine," said study senior author Dr. Edgar Engleman, professor of pathology and medicine at Stanford University School of Medicine in Palo Alto, Calif.

Meanwhile, the development of colon cancer has been linked to inflammation. For example, inflammatory bowel disease, such as ulcerative colitis, has been associated with colon cancer, he said in a university news release.

"We wanted to connect the dots and learn whether and how retinoic acid levels directly affect cancer development," Engleman added.

When the researchers looked at mice with colon cancer, they saw lower levels of retinoic acid in the intestines of the mice.

The researchers also found that boosting levels of retinoic acid in the intestines of mice with colon cancer slowed progression of the disease.

In humans, colon cancer patients who had high levels of a protein that degrades retinoic acid in their intestinal tissue tended to have worse outcomes than other patients, the study authors noted.

The findings suggest new ways to prevent or treat colon cancer. However, it's important to note that animal research doesn't always produce the same results in humans.

"The intestine is constantly bombarded by foreign organisms. As a result, its immune system is very complex," Engleman said.

"We found that bacteria, or molecules produced by bacteria, can cause a massive inflammatory reaction in the gut that directly affects retinoic acid metabolism," he said.

He said that retinoic acid levels are normally regulated very tightly.

"Now that we've shown a role for retinoic acid deficiency in colorectal cancer, we'd like to identify the specific microorganisms that initiate these changes in humans. Ultimately we hope to determine whether our findings could be useful for the prevention or treatment of colorectal cancer," he concluded.

The study was published online Aug. 30 in the journal Immunity.

Combo Drug for Childhood Asthma Appears Safe in Study

In continuation of my update on fluticasone 

Lingering safety concerns regarding an asthma drug for children may be put to rest by new clinical trial results showing the widely used medication is safe, according to a new report.

Long-acting beta agonists (LABAs) provide short-term relief of asthma symptoms by relaxing and opening the airways. They're prescribed to child asthma sufferers in combination with an inhaled steroid drug to reduce airway inflammation, said study co-author Dr. Stanley Szefler. He is director of pediatric asthma research for the University of Colorado School of Medicine.

"Together they have a dual purpose, one to reduce inflammation and the other to open up the airways to make it easier to breathe," Szefler said.

But a 2008 analysis by the U.S. Food and Drug Administration questioned the safety of LABAs, noting that some studies had found an increased risk of asthma-related deaths in adults and asthma-related hospitalizations in children.

Based on the analysis, the FDA slapped a "boxed warning" label on the drugs, which calls attention to serious or life-threatening risks. The agency also asked GlaxoSmithKline, the manufacturer of a LABA intended for children, to perform a large-scale safety trial for its product, researchers said in background information.

The clinical trial, conducted by Szefler and his colleagues, found that children using a combination LABA/steroid inhaler -- sold as Glaxo's Advair Diskus-a powder form of fluticasone and salmeterol  ( -- did not have any greater risk of harm than children using an inhaler loaded only with a steroid.

  fluticasone   salmeterol

The results have been forwarded to the FDA, which now will decide whether to lift the black box warning, Szefler said.

"The next step is for the FDA to assemble all the available studies, make their own interpretation and determine how that would affect product labeling," he said.

The LABA/steroid combination drug is a valuable option that asthma doctors often use when inhaled steroids alone don't help kids with chronic asthma, said Dr. Alfin Vicencio, chief of pediatric pulmonology at Mount Sinai Hospital in New York City.

The boxed warning has impeded use of that option, he said.

"Not infrequently, families whose children could benefit from this medication decline on the medication specifically because of that warning," Vicencio said. "This manuscript not only gives physicians a little more reassurance, but parents as well."

In the safety trial, researchers recruited more than 6,200 children between 4 and 11 years old. They were randomly assigned inhalers containing a combination of salmeterol (a LABA) and fluticasone (a steroid), or fluticasone alone.

Of all the patients, 27 in the combination drug group had a serious asthma-related event that required hospitalization, compared with 21 in the steroid-only group. There were no deaths, and no emergencies that required insertion of a breathing tube.

The study results appear in the Sept. 1 issue of the New England Journal of Medicine.

The past safety concerns might have cropped up because patients were using an LABA without also taking a steroid alongside it, Szefler said. LABAs provide only short-term relief, and do nothing to treat the chronic airway inflammation targeted by steroids.

"In asthma, when you're using the long-acting beta agonist it should be combined with a steroid," he said.

Inhaled steroids will remain the front-line option for kids with chronic asthma, but this trial shows the combination drug is "a tool that can be used for those children that require something in addition to steroids for their persistent asthma," said Dr. Marilyn Li. She is an assistant professor of clinical pediatrics at the University of Southern California's Keck School of Medicine.

"There's been widespread fear about that kind of medication because of the long-acting beta agonist component, and unjustly so because, truthfully, for those children who have moderate to severe asthma, there is a serious unmet need," Li said.

Newer Epilepsy Drugs May Be Safer During Pregnancy

In continuation of my update on  levetiracetam and topiramate 

  Topiramate    Levetiracetam 

Women who take the new epilepsy drugs levetiracetam and topiramate during pregnancy don't run the risk of harming their infant's mental development, British researchers report.

But the commonly prescribed anti-seizure drug valproate was linked with lower IQs in children, especially when taken at higher doses, researchers say.

"The treatment of epilepsy in women who are considering a pregnancy or are pregnant involves optimizing the health of the mother as well as keeping the risk to the fetus as low as possible," said lead researcher Rebecca Bromley, a research fellow at the Institute for Human Development at the University of Manchester.

In the study, children exposed to levetiracetam (Keppra) or topiramate (Topamax) in the womb did not differ from children not exposed to these drugs. And they had better outcomes than the children exposed to valproate (Depakote) in terms of their IQ, thinking and language skills, Bromley said.

"These data can be used by doctors and women to help them make their decisions about which medication is best for them," she added.

For the study, Bromley and her colleagues used the U.K. Epilepsy and Pregnancy Register to identify 171 women with epilepsy who had a child between 5 and 9 years old. During their pregnancy, 42 of the women took levetiracetam, 27 took topiramate, and 47 took valproate, the researchers said.

Bromley's team compared the women with epilepsy with 55 women who did not take epilepsy drugs during pregnancy. The children had their IQ measured and took tests on verbal and nonverbal comprehension and how fast they could process visual information.

The researchers found that children of women who took levetiracetam or topiramate did not have lower IQs or other thinking-skill problems, compared with kids of mothers who did not take these drugs, no matter what dose of these drugs were taken.

Children whose mothers took valproate, however, had the lowest IQs of the study, Bromley said. These kids scored, on average, 11 points lower on the IQ test.

Among children whose mothers took valproate, 19 percent had IQs lower than the average score of 100, compared with 6 percent among kids whose mothers did not take any epilepsy drugs during pregnancy, the researchers found.

Because the registry the researchers used does not include all women with epilepsy, the findings might not apply to all women with the conditions, Bromley noted. She also said that topiramate, one of the newer drugs, has been associated with an increased risk of birth defects, such as cleft lip and palate.

The study was funded by Epilepsy Research U.K. and the report was published online Aug. 31 in the journalNeurology.

Dr. Ian Miller is a pediatric neurologist and medical director of the comprehensive epilepsy program at Nicklaus Children's Hospital in Miami. "This study means that we have a little bit more information for women who become pregnant while taking epilepsy medicines," he said.

The exact risks of taking any medicine during pregnancy are very difficult to know, he added.

"As a result, many questions remain," Miller said. "But this study gives doctors a reason to choose topiramate or levetiracetam, which did not show a measurable effect on the child's development, rather than valproate, which did."

Women who are on valproate because they already tried other medications and "moved on because those medications were less effective, will face some difficult decisions," he said.

"Any woman of childbearing potential should discuss this aspect of their medical management with their doctor, especially in light of these new findings," Miller added.

Researchers identify promising new drug treatment for cocaine addiction

A team of researchers led by Cardiff University has discovered a promising new drug treatment for cocaine addiction.

The experimental therapy, which involves administering a drug currently used in cancer therapy trials, treats cocaine addiction by inhibiting memories responsible for cravings.

Professor Riccardo Brambilla from Cardiff University's School of Biosciences said: "We have demonstrated that a single administration of a trial drug from the pharmacompany Pfizer can completely obliterate cocaine associated memories and significantly accelerate the end of drug seeking behaviour in animals. With this drug currently being used in cancer trials, it could be easily repositioned for treatment of cocaine addiction and other drugs of abuse."

Cocaine produces its addictive effects partially by acting on the brain's limbic system - a set of interconnected regions that regulate pleasure and motivation. When a person uses cocaine, memories of the intense pleasure felt and the things associated with it are newly created. It is these long lasting memories and drug-associated cues, key to the transition from recreational drug taking to compulsive drug use, which the new treatment inhibited when tested on mice.

Dr Stefania Fasano from Cardiff University added, "With drug use recently on the rise, new treatments for breaking addiction are much needed. The availability of a powerful drug from Pfizer, already validated in humans, could speed up the clinical development of our findings."

The research is published in the journal eLife.

This was an experimental study in mice, which allows for conclusions to be made about cause and effect in this species. To learn about the effect of this treatment in people experimental trials with humans will be necessary.

Ref : https://elifesciences.org/content/5/e17111

Combination drug therapy safe, effective in treating asthma patients

In continuation of my update formoterol and  budesonide

A post-marketing safety study mandated by the U.S. Food and Drug Administration has shown that a combination drug therapy for the treatment of asthma is safe and effective.

The therapy tested consisted of a long-acting beta agonist, formoterol, added to an inhaled glucocorticoid, budesonide.

 Formoterol     Budesonide 

"Our study showed no significant increase in serious adverse events in the combination therapy," said Stephen Peters, M.D., Ph.D., professor of pulmonary, critical care, allergy and immunologic diseases at Wake Forest Baptist Medical Center and lead author of the study.

"A large number of studies have shown that this type of combination therapy really helps asthma control and decreases symptoms. Our findings, in combination with results from another FDA-mandated safety study, are very reassuring to those of us who treat asthmatic patients."

The study is published in the Sept. 1 issue of the New England Journal of Medicine.

In this multicenter, double-blind, 26-week study, the scientists evaluated whether the addition of formoterol to budesonide maintenance therapy increased the risk of serious asthma-related events in patients with moderate to severe asthma. Study participants were age 12 or older, had persistent asthma, received daily asthma medication and had one to four exacerbations in the previous year.

Of the 11,693 patients enrolled in the study, an asthma-related event occurred in 43 patients who received the combination therapy of budesonide and formoterol and in 40 patients who received only budesonide. Two asthma-related deaths were reported in the combination arm of the study and none in the single-therapy group, which is not statistically significant.

In addition, a secondary finding showed a 16.5 percent decrease in asthma exacerbations in the combination therapy group as compared to the group receiving budesonide.

Overall, the researchers found that treatment with budesonide-formoterol was associated with a lower risk of asthma exacerbations than budesonide and a similar risk of serious asthma-related events.

Added benefit still not proven for epilepsy drug

In continuation of my updates Briviact

Brivaracetam (trade name: Briviact) has been approved since January 2016 as add-on therapy for adults and adolescents from 16 years of age with epileptic seizures. The German Institute for Quality and Efficiency in Health Care (IQWiG) had already examined the drug in an early benefit assessment published in May. For several reasons, the indirect comparisons presented by the drug manufacturer were unsuitable to assess an added benefit in comparison with the appropriate comparator therapy. Among other things, the manufacturer had not analysed all relevant outcomes. In the commenting procedure, the manufacturer presented a further indirect comparison.

In the addendum thereupon commissioned to IQWiG by the Federal Joint Committee (G-BA), the Institute has now concluded that this new indirect comparison is methodologically better. Among other things, the manufacturer has now analysed the missing outcomes. However, this indirect comparison submitted subsequently still fails to show an added benefit of brivaracetam over the appropriate comparator therapy.

New analyses only partly rectify the deficits

In its dossier assessment in May, IQWiG criticized that not all brivaracetam studies presented by the manufacturer were relevant for the benefit assessment, that the studies were insufficiently similar for informative indirect comparisons, that the manufacturer had not presented analyses of all relevant outcomes, and that the comparator therapies had not been recognizably customized for the individual patient, as demanded by the G-BA.

The new indirect comparison submitted subsequently by the manufacturer addresses the first 3 points of criticism. The brivaracetam study is relevant for the research question, the studies used for the comparison are sufficiently similar to this study, and further patient-relevant outcomes are addressed. However, the problem remains unsolved that treatment in the control arms was not customized for the individual patient and thus does not correspond to the appropriate comparator therapy.

Non-inferiority of brivaracetam questionable

Independent of the question as to whether the appropriate comparator therapy specified by the G-BA was implemented, in the overall consideration, the indirect comparison shows no advantage of brivaracetam over lacosamide. Neither advantages nor disadvantages of brivaracetam were shown in the outcome categories "mortality" and "health-related quality of life" in comparison with lacosamide.

In the category "side effects", significant effects were shown in favour of brivaracetam (for serious adverse events and some specific adverse events, such as dizziness or eye disorders). However, the available data on the morbidity outcomes "seizure frequency", "50% responder rate" and "freedom of seizure", raise doubts that brivaracetam is at least equally effective as lacosamide. For seizure frequency, the one lacosamide study fails to show a clear advantage or disadvantage of brivaracetam, while the other shows a statistically significant disadvantage of the new drug compared with lacosamide. Both lacosamide studies also deliver heterogeneous results for the two other outcomes, which, however, do not lead to statistically significant advantages or disadvantages.

Overall, the indirect comparison therefore does not show an advantage of brivaracetam over the comparator therapy.

Seeds of tropical shrub guarana contain ten times more amount of catechins than green tea

 

In continuation of my update on catechins. 

The millions of people who consume green tea all over the world benefit from the catechins it contains. Catechins are a class of chemical compounds with anti-oxidant and anti-inflammatory properties, among other healthy ingredients. Researchers at the University of São Paulo's Public Health School (FSP-USP) have discovered that guarana (Paullinia cupana) is a worthy competitor, at least as far as catechins are concerned: the seeds of the tropical shrub, used in fizzy drinks that are among the most popular in Brazil, as well as in over-the-counter supplements, contain more than ten times the amount of catechins found in green tea.

 Catechins

A clinical trial with healthy human volunteers has demonstrated that guarana is a rich source of catechins, which, when properly absorbed, reduce the oxidative stress associated with the development of neurodegenerative and cardiovascular disorders, as well as diabetes, cancer, inflammation and premature aging due to cell death, among other conditions harmful to health and wellbeing.

"Guarana has always been seen above all as a stimulant, especially by the international scientific community, because of its high caffeine content. We also found few Brazilian scientific studies that seek to identify other biological effects of guarana," said Lina Yonekura, the principal investigator for this research and currently an assistant professor at Kagawa University's School of Agriculture in Japan. "This pioneering assessment of the absorption and biological effects of its catechins in human volunteers should foster interest in guarana as a functional food on the part of scientists, the market, and society in general."

The paper with the results of the study is featured on the cover of the latest issue ofFood & Function, published by the Royal Society of Chemistry in the United Kingdom as one of the "Hot Articles in Food & Function 2016.

The month-long study was conducted in two stages. After selecting volunteers who were healthy but slightly overweight and with a moderately elevated risk of cardiovascular disease, the researchers measured baseline parameters on the first day and evaluated the same items again on day 15 after a the implementation of a controlled diet.

The participants were then asked to take guarana at home every morning before breakfast for the next fortnight. They were given bottles containing guarana seed powder and instructed to prepare a daily drink with the contents of one bottle (3 g of guarana powder) in 300 mL of water.

This procedure ensured that each participant acted as his or her own control. The researchers compared the same volunteers' blood tests at different times to avoid the influence of variability between individuals. The acute effect of guarana was measured one hour after the participants drank the solution on day 1 and day 15. The prolonged effect was assessed after overnight fasting on the same days.

The researchers assessed the extent to which guarana affected oxidative stress markers during the two-week intervention period. They also performed a detailed study to evaluate the subjects' absorption of catechins and their metabolites, as they had found no information in the scientific literature on the bioavailability of these compounds in guarana.

The oxidative stress markers included oxidation of low-density lipoprotein (LDL), popularly known as bad cholesterol. LDL is essential to an organism's proper functioning because it is the main particle that carries cholesterol to cells. Cholesterol is a structural component of all cell membranes and is used to manufacture steroid hormones (estrogen and testosterone). When oxidized, however, LDL causes atherosclerosis and increases the risk of cardiovascular disease. The tests performed by Yonekura's team showed an increase in oxidation resistance of the LDL in the blood samples taken from the volunteers after they drank guarana.

They also performed a comet assay, also called single cell gel electrophoresis (SCGE), a technique for quantifying and analyzing DNA damage in individual cells due to various factors, including oxidative stress. In this case, lymphocyte DNA in blood samples taken one hour after guarana intake was less damaged than expected when submitted to an oxidizing environment, indicating the presence of anti-oxidant substances or enhanced performance of the lymphocytes' enzymatic anti-oxidant system.

"All these markers depend on the presence of catechins in the bloodstream," Yonekura said. "The improvement in the parameters we assessed was associated with a rise in the concentration of plasma catechins after guarana intake, showing that guarana was indeed responsible for this effect."

Moreover, she went on, the guarana catechins strengthened the cells' native anti-oxidant enzymes, especially glutathione peroxidase, catalase, and superoxide dismutase, which combine to convert superoxide into peroxide and finally into water, protecting cells from the oxidative damage caused by their own metabolism of outside factors.

The tests showed increased glutathione peroxidase and catalase activity both shortly after guarana ingestion and on the following day.

"These results are exciting, suggesting that the bioavailability of guarana catechins is equal to or greater than that of green tea, cocoa and chocolate catechins," Yonekura said. "In fact, their bioavailability was sufficient to have a positive effect on plasma anti-oxidant activity, protect erythrocyte DNA, reduce plasma lipid oxidation, and increase anti-oxidant enzyme activity. We hope the results lead to heightened interest in guarana as the species is native to the Amazon, and Brazil is practically the only country that produces it on a commercial scale."

Study shows how caffeine counteracts age-related cognitive deficits in animals

A study published in the journal Scientific Reports from Nature publishing group, describes the mechanism by which caffeine counteracts age-related cognitive deficits in animals.

The study coordinated by Portuguese researchers from Instituto de Medicina Molecular (iMM Lisboa) and collaborators from Inserm in Lille, France, along with teams from Germany and United States, showed that the abnormalexpression of a particular receptor - the adenosine A2A, target for caffeine - in the brain of rats induces an aging-like profile namely memory impairments linked to the loss of stress controlling mechanisms.

"This is part of a larger study initiated 4 years ago in which we identified the role of this receptor in stress, but we did not know whether its activation would be sufficient to trigger all the changes. We now found that by altering the amount of this receptor alone in neurons from hippocampus and cortex - memory related areas - is sufficient to induce a profile that we designate as 'early-aging' combining the memory loss and an increase in stress hormones in plasma (cortisol)" - explains Luisa Lopes, Group Leader at iMM Lisboa and the coordinator of the study.

When the same animals were treated with a caffeine analogue, which blocks the action of adenosine A2A receptors, both memory and stress related deficits were normalized.

David Blum, from Inserm research director, adds: "In elderly people, we know there is an increase of stress hormones that have an impact on memory. Our work supports the view that the procognitive effects of A2AR antagonists, namely caffeine, observed in Alzheimer's and age-related cognitive impairments may rely on this ability to counteract the loss of stress controlling mechanisms that occurs upon aging"

This is important not only to understand the fundamental changes that occur upon aging, but it also identifies the dysfunctions of the adenosine A2A receptor as a key player in triggering these changes. And a very appealing therapeutic target" - concludes Luisa Lopes.

Study shows how caffeine counteracts age-related cognitive deficits in animals: A study published in the journal Scientific Reports from Nature publishing group, describes the mechanism by which caffeine counteracts age-related cognitive deficits in animals.