Johns Hopkins researchers have discovered that valproic acid, a widely prescribed drug for treating epilepsy, has the additional benefits of reducing fat accumulation in the liver and lowering blood sugar levels in the blood of obese mice. A summary of their research appears in this month’s issue of the journal Molecular Pharmacology.
The liver cells (magenta) of untreated obese mice (left) contain many large, white droplets of fat while those of obese mice treated with valproic acid (right) have much less fat accumulation.
Used with permission of Molecular Pharmacology and Namandje Bumpus.
Fatty liver disease can lead to liver failure and is often caused by obesity and a high-fat diet. Obesity is also associated with the development of type 2 diabetes, which sabotages the body’s process for controlling blood sugar levels. A rapidly rising problem in the developed world, obesity currently affects over 90 million Americans.
Studying the ways in which the cytochrome P450 family of enzymes processes valproic acid, the Johns Hopkins biochemists found that it can activate the protein AMPK, which was already known to be a good drug target for treating metabolic disorders like type 2 diabetes and obesity.
The Bumpus laboratory studies how drugs are processed in cells by enzymes of the cytochrome P450 family. Humans have 57 of these enzymes, and several of them work on the drug valproic acid. In the course of their research, Namandjé Bumpus, Ph.D., assistant professor of pharmacology, and postdoctoral fellow Lindsay Avery, Ph.D., found that valproic acid could activate AMPK in mouse and human liver cells in a dose-dependent way.
“It was exciting to find that valproic acid can activate AMPK,” Bumpus says. “What’s even better is that its byproducts can activate AMPK at much lower doses. That’s a desirable quality if you want to eventually use it to treat people.”
Knowing that valproic acid is extensively processed by cytochrome P450 enzymes, the research team added a cytochrome P450 inhibitor to mouse and human liver cells and found that AMPK was no longer activated. This suggested that the byproducts of valproic acid, as opposed to valproic acid itself, were the molecules activating AMPK. To test this theory, they added four chemically modified versions of the drug to the cells and found that the derivatives were able to activate AMPK without valproic acid. In fact, they achieved higher activation of AMPK at one-fortieth the concentration.
To assess the uptake and breakdown of valproic acid in living organisms, they gave the drug to obese mice with high blood sugar levels, fatty livers and rapid weight gain. Treated mice showed decreased blood sugar levels, decreases in the size and the fat accumulation of their livers, and a stabilization of weight — rather than the continued weight gain experienced by untreated mice.
“The improvements seen in the health of these obese mice were very encouraging,” says Bumpus. “We hope that we will find similar results in obese people who take valproic acid.”
This work was supported by a grant from the National Institute of General Medical Sciences (R01GM103853).
Catherine Kolf | EurekAlert!
Exploring a new frontier of cyber-physical systems: The human body
18.05.2015 | National Science Foundation
Soft-tissue engineering for hard-working cartilage
18.05.2015 | Technische Universitaet Muenchen
Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.
Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...
Development and implementation of an advanced automobile parking navigation platform for parking services
To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...
The world's first electrical car and passenger ferry powered by batteries has entered service in Norway. The ferry only uses 150 kWh per route, which...
On Tuesday, 19 May 2015 the research icebreaker Polarstern will leave its home port in Bremerhaven, setting a course for the Arctic. Led by Dr Ilka Peeken from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) a team of 53 researchers from 11 countries will investigate the effects of climate change in the Arctic, from the surface ice floes down to the seafloor.
RV Polarstern will enter the sea-ice zone north of Spitsbergen. Covering two shallow regions on their way to deeper waters, the scientists on board will focus...
Nanoengineers at the University of California, San Diego developed a gel filled with toxin-absorbing nanosponges that could lead to an effective treatment for skin and wound infections caused by MRSA (methicillin-resistant Staphylococcus aureus), an antibiotic-resistant bacteria. This "nanosponge-hydrogel" minimized the growth of skin lesions on mice infected with MRSA - without the use of antibiotics. The researchers recently published their findings online in Advanced Materials.
To make the nanosponge-hydrogel, the team mixed nanosponges, which are nanoparticles that absorb dangerous toxins produced by MRSA, E. coli and other...
20.05.2015 | Event News
18.05.2015 | Event News
12.05.2015 | Event News
22.05.2015 | Materials Sciences
22.05.2015 | Information Technology
22.05.2015 | Materials Sciences