Navigation Links
Study puts a new spin on ibuprofen's actions
Date:9/25/2011

Ibuprofen, naproxen, and related non-steroidal anti-inflammatory drugs (NSAIDs) the subjects of years of study still have some secrets to reveal about how they work.

Vanderbilt University investigators have discovered surprising new insights into the actions of NSAIDs. Their findings, reported Sept. 25 in Nature Chemical Biology, raise the possibility of developing a new class of inflammation- and pain-fighting medicines.

NSAIDs block the activity of the cyclooxygenase enzymes, COX-1 and COX-2.

"Until about three years ago, we thought we knew everything there was to know about these enzymes and these inhibitors, but we were unaware of some of the details of how they work," said Lawrence Marnett, Ph.D., director of the Vanderbilt Institute of Chemical Biology and professor of Biochemistry, Chemistry and Pharmacology.

COX-1 and COX-2 oxygenate (add oxygen to) the lipid arachidonic acid to generate biologically active prostaglandins. Marnett and his team discovered about 10 years ago that COX-2 (but not COX-1) also oxygenates endocannabinoids naturally occurring analgesic and anti-inflammatory agents that activate cannabinoid receptors (the same receptors that marijuana activates).

The investigators then made a puzzling observation. They found that ibuprofen was a more potent inhibitor of endocannabinoid metabolism compared to arachidonic acid metabolism.

"This was the same drug inhibiting two substrates of the same protein differently," Marnett said. "We didn't understand it."

In the current report, the researchers surveyed a series of different types of NSAIDs for inhibition of COX-2. They included the "mirror-image" versions of ibuprofen, naproxen and flurbiprofen (these drugs come in two different chemical configurations a "right hand" (R) version and a "left hand" (S) version over-the-counter ibuprofen is a mixture of both forms). It had previously been assumed that only the S-forms of these NSAIDs (S-profens) were able to inhibit COX-2.

Marnett and colleagues found that the R-profens inhibited endocannabinoid, but not arachidonic acid, oxygenation.

The researchers also determined that R-profens selectively block endocannabinoid metabolism in isolated dorsal root ganglia (neurons and glial cells from the spinal column). They found that treatment of these cultures with an inflammatory stimulus increased expression of COX-2 and stimulated release of arachidonic acid and endocannabinoids, which were oxidized by COX-2. The R-profens inhibited metabolism of the endocannabinoids (and increased their concentrations), but not arachidonic acid.

The findings offer a potential explanation for the reported observation that R-flurbiprofen is analgesic in people and that it inhibits neuropathic pain in a mouse model.

"We're proposing that R-flurbiprofen is effective in this neuropathic pain setting because it is preventing the metabolism of endocannabinoids by COX-2; so it's maintaining endocannabinoid tone and that's the basis for the analgesic activity," Marnett said.

"It's exciting because you will only see this effect at sites of inflammation where COX-2 might play a role in depleting endocannabinoids. Selective inhibitors like the R-profens could represent a new way to target analgesia without having the GI, and maybe cardiovascular, side effects of traditional NSAIDs."

Marnett and his team will pursue this idea by studying in vivo models of neuroinflammation to determine if these drugs and new compounds they are developing work to inhibit endocannabinoid oxidation and maintain endocannabinoid tone.


'/>"/>

Contact: Leigh MacMillan
leigh.macmillan@vanderbilt.edu
615-322-4747
Vanderbilt University Medical Center
Source:Eurekalert  

Related biology news :

1. University of Arizona to study human-fire-climate interactions
2. Aquarium fishes are more aggressive in reduced environments, a new study finds
3. Harvard School of Public Health awarded $20 million CDC grant to study HIV prevention in Botswana
4. Twin study reveals epigenetic alterations of psychiatric disorders
5. Causes of Gulf War Illness are complex and vary by deployment area -- Baylor University study
6. Study finds bidirectional relationship between schizophrenia and epilepsy
7. CONRAD presents results of pivotal contraceptive study at Reproductive Health 2011
8. Study in underwater laboratory may help manage seaweed-eating fish that protect coral
9. Study finds an increase of children accidentally poisoned with pharmaceuticals
10. UF-led study: Invasive amphibians, reptiles in Florida outnumber world
11. Voting causes stress according to Ben-Gurion University of the Negev study
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Study puts a new spin on ibuprofen's actions
(Date:6/22/2016)... , June 22, 2016   ... management and verification solutions, has partnered with ... software solutions for Visitor Management, Self-Service Kiosks ... provides products that add functional enhancements to ... provides corporations and venues with an automated ...
(Date:6/15/2016)... 15, 2016 Transparency Market ... Recognition Market by Application Market - Global Industry Analysis Size ... to the report, the  global gesture recognition market ... and is estimated to grow at a CAGR ... 2024.  Increasing application of gesture recognition ...
(Date:6/2/2016)... 2016 The Department of Transport Management ... 44 million US Dollar project, for the , ... Personalization, Enrolment, and IT Infrastructure , to ... and implementation of Identity Management Solutions. Numerous renowned international vendors ... Decatur was selected for the most compliant and ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... , June 24, 2016  Regular discussions on a ... take place between the two entities said Poloz. ... Ottawa , he pointed to the country,s ... the federal government. ... said, "Both institutions have common economic goals, why not sit ...
(Date:6/24/2016)... ... June 24, 2016 , ... Researchers at the Universita Politecnica delle Marche in ... peritoneal or pleural mesothelioma. Their findings are the subject of a new article on ... biomarkers are signposts in the blood, lung fluid or tissue of mesothelioma patients that ...
(Date:6/23/2016)... 23, 2016   Boston Biomedical , an ... designed to target cancer stemness pathways, announced that ... Orphan Drug Designation from the U.S. Food and ... cancer, including gastroesophageal junction (GEJ) cancer. Napabucasin is ... inhibit cancer stemness pathways by targeting STAT3, and ...
(Date:6/23/2016)... 2016 Houston Methodist Willowbrook Hospital has ... Association to serve as their official health care ... Willowbrook will provide sponsorship support, athletic training services, ... coaches, volunteers, athletes and families. "We ... Association and to bring Houston Methodist quality services ...
Breaking Biology Technology: