(Press-News.org) Fish oil is touted for its anti-inflammatory and anti-diabetic benefits, but scientist weren't sure how the omega-3 fatty acids in fish oil work. Now, according to a report in the September 3rd issue of the journal Cell, scientists have nailed how omega-3 fatty acids both shut down inflammation and reverse diabetes in obese mice.
Omega-3s alleviate inflammation by acting on a receptor (GPR120) found in fat tissue and on inflammatory immune cells called macrophages, studies in mice show.
"Omega-3s are very potent activators of GPR120 on macrophages -- more potent than any other anti-inflammatory we've ever seen," said Jerrold Olefsky of the University of California, San Diego.
In fact, there are all sorts of ways to trigger inflammation, he added. Activation of GPR120 by omega-3s blocks not one, but all inflammatory pathways.
GPR120 is a G protein-coupled receptor (GPCRs), a group involved in many important cell functions and that includes the targets of many drugs. Other researchers had recently shown that five orphan GPCRs, GPR120 included, respond to free fatty acids.
Olefsky's team focused on GPR120 from the start because of where it turned up -- in fat tissue and on macrophages. If your goal is to fight inflammation, "that's just where you'd want them to be expressed," Olefsky said.
Once they knew how omega-3s were working through GPR120, the researchers looked to a mouse that lacked the receptor. When those animals were made obese on a high-fat diet and treated with omega-3 fatty acids, they showed all the signs of inflammation and the insulin resistance that leads to diabetes; the omega-3s didn't help at all. Normal mice on a high-fat diet of course still gained weight, but omega-3s "had a really robust effect in preventing inflammation," Olefsky said. That anti-inflammatory effect acted as an insulin sensitizer, and a pretty good one at that. The omega-3 treatment was as effective, or even more effective, than the popular insulin-sensitizing drug Rosiglitazone (trade name Avandia).
Olefsky said the dose of omega-3 it took to get these effects in the mice was enough to double their blood concentrations. "That's a big increase," he said, "but not unbelievable."
What any of this means for humans isn't yet clear, but a large number of people are already supplementing their diets with fish oil and an omega-3 prescription drug is already on the market for some indications. Olefsky isn't going to make any recommendation at this point, but says he doesn't see much of a downside to taking the supplements "as long as it isn't in enormous doses."
There are more details the researchers hope to work out. For one, omega-3s seem to block the migration of macrophage cells into body tissues. "It's a remarkable effect, and we don't know its action," he said.
While omega-3s appear to be very good at what they do in activating GPR120 to curb inflammation, it's possible that a small molecule could be found to work even better, Olefsky said, noting that omega-3 has a relatively low affinity for the receptor.
One interesting tidbit that Olefsky says even many scientists don't know: Like us, fish don't actually produce omega-3 fatty acids very efficiently at all. Instead, they become enriched with the fatty acids by eating algae.
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The researchers include Da Young Oh, University of California, San Diego, La Jolla, CA; Saswata Talukdar, University of California, San Diego, La Jolla, CA; Eun Ju Bae, University of California, San Diego, La Jolla, CA; Takeshi Imamura, Shiga University of Medical Science, Tsukinowa, Seta, Otsu-city, Shiga, Japan; Hidetaka Morinaga, University of California, San Diego, La Jolla, CA; WuQiang Fan, University of California, San Diego, La Jolla, CA; Pingping Li, University of California, San Diego, La Jolla, CA; Wendell J. Lu, University of California, San Diego, La Jolla, CA; Steven M. Watkins, Tethys Bioscience, West Sacramento, CA; and Jerrold M. Olefsky, University of California, San Diego, La Jolla, CA.
LA JOLLA, CA – August 30, 2010 –– An international team led by scientists from The Scripps Research Institute, the Swiss Tropical Institute, the Genomics Institute of the Novartis Research Foundation and the Novartis Institute for Tropical Diseases has discovered a promising new drug candidate that represents a new class of drug to treat malaria. Clinical trials for the compound are planned for later this year.
The research was published on September 3, 2010, in the prestigious journal Science.
"We're very excited by the new compound," said Elizabeth Winzeler, a Scripps ...
Athens, Ga. – Stem cells might be thought of as trunks in the tree of life. All multi-cellular organisms have them, and they can turn into a dazzling variety other cells—kidney, brain, heart or skin, for example. One class, pluripotent stem cells, has the capacity to turn into virtually any cell type in the body, making them a focal point in the development of cell therapies, the conquering of age-old diseases or even regrowing defective body parts.
Now, a research team at the University of Georgia has shown for the first time that a gene called Myc (pronounced "mick") ...
Kidney transplants that show a combination of fibrosis (scarring) and inflammation after one year are at higher risk of long-term transplant failure, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN).
To identify these abnormalities, doctors would need to perform routine biopsies on apparently normal kidney transplants—rather than waiting for problems to occur. "Even for some transplants that would be expected to have a very long graft survival, protocol biopsies performed in the first year may indicate the ...
Researchers at the University of California, San Diego School of Medicine have identified the molecular mechanism that makes omega-3 fatty acids so effective in reducing chronic inflammation and insulin resistance.
The discovery could lead to development of a simple dietary remedy for many of the more than 23 million Americans suffering from diabetes and other conditions.
Writing in the advance online edition of the September 3 issue of the journal Cell, Jerrold Olefsky, MD, and colleagues identified a key receptor on macrophages abundantly found in obese body fat. ...
DURHAM, N.C. – Duke University Medical Center researchers have found two genes in mice which might help identify why some people are more susceptible than others to potentially deadly staph infections.
The researchers uncovered important genetic clues that ultimately could help inform patient management and drug development.
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Results of a study reported in the September issue of the Journal of the American Geriatrics Society suggest that Veterans with post-traumatic stress disorder (PTSD) have a greater risk for dementia than Veterans without PTSD, even those who suffered traumatic injuries during combat.
Exposure to life threatening events, like war, can cause PTSD, and there are high rates among veterans. PSTD includes symptoms such as avoiding things or people that remind a person of the trauma, nightmares, difficulty with sleep, and mood problems.
"We found Veterans with PTSD had ...
DURHAM, N.H. – New research from the University of New Hampshire shows that the "gateway effect" of marijuana – that teenagers who use marijuana are more likely to move on to harder illicit drugs as young adults – is overblown.
Whether teenagers who smoked pot will use other illicit drugs as young adults has more to do with life factors such as employment status and stress, according to the new research. In fact, the strongest predictor of whether someone will use other illicit drugs is their race/ethnicity, not whether they ever used marijuana.
Conducted by UNH associate ...
Roberto Carlos' free kick goal against France in 1997's Tournoi de France is thought by many to have been the most skilful free kick goal - from 35m with a powerful curling banana trajectory - ever scored; but by others to have been an incredible fluke.
Taken in 1997, a year before the French won the World Cup, Brazilian Carlos's goal held France to a frustrating draw but, now, a group of French physicists – perhaps with a nostalgic eye to a happier time for French football – have computed the trajectory and shown that Carlos' goal was no fluke.
The research published ...
Heidelberg, 3 September 2010 – Our cerebral cortex, or pallium, is a big part of what makes us human: art, literature and science would not exist had this most fascinating part of our brain not emerged in some less intelligent ancestor in prehistoric times. But when did this occur and what were these ancestors? Unexpectedly, scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have now discovered a true counterpart of the cerebral cortex in an invertebrate, a marine worm. Their findings are published today in Cell, and give an idea of what ...
Montreal, September 3, 2010 – Dr. Éric A. Cohen, Director of the Human Retrovirology research unit at the Institut de recherches cliniques de Montréal (IRCM), and his team published yesterday, in the online open-access journal PLos Pathogens, the results of their most recent research on the role of the Vpr protein in HIV (human immunodeficiency virus) infection and AIDS (acquired autoimmune deficiency syndrome).
"We previously identified that HIV, when infecting target cells, blocks cell division and induces cell death," says Dr. Cohen. "We then discovered that the Vpr ...
