There is no cure for obesity, but researchers at the University of Alabama at Birmingham suggest a treatment that could reverse its damaging effects. The mouse study shows that a therapy involving the continuous release of nitric oxide could help with obesity and related conditions like Type 2 diabetes.
Nitric oxide is a gaseous signaling-chemical involved in relaxing the inner muscles of blood vessels. Scientists say providing it as a therapeutic treatment could be highly effective for patients struggling with their weight.
“Because reduced bioavailability of nitric oxide is the hallmark of cardiometabolic syndrome, supplying exogenous nitric oxide at a sustained level may be an efficient way of treating the cardiometabolic syndrome,” comments Jeonga Kim, PhD, leader of the UAB study in a statement. “The strategy of reducing body weight by the local delivery of nitric oxide may be a novel, efficient and safe way to prevent and treat multiple metabolic diseases.”
The study authors built a nanomatrix gel that releases a burst of nitric oxide for the first 24 hours followed by a sustained nitric oxide release for a month. The gel was injected under the skin of 8-week-old mice every two weeks for 12 weeks. Mice were fed a high-fat diet to simulate obesity and insulin resistance in humans caused by a poor diet.
After 12 weeks, mice given nitric oxide had 17% less body weight than mice who did not have nitric oxide. The researchers confirmed the weight difference came from a loss of fat and not lean mass or water weight. Results also showed increased phosphorylation of the enzyme hormone-sensitive lipase and a decrease in the fat cell size in epididymal white adipose tissue. Breaking down fats could explain the weight loss.
Beyond weight loss, mice injected with nitric oxide showed better glucose tolerance and a reduction in fasting serum insulin and leptin levels. Signs of inflammation were also decreased in nitric-oxide mice.
One of the nitric oxide’s roles is to stimulate mitochondrial biogenesis, a mechanism to convert white adipocytes to beige adipocytes. The brown fat helps preserve core body temperature in cold conditions by producing heat. The fat cells in brown adipose tissue were smaller in nitric-oxide mice than in the control group.
Another benefit of receiving the nitric oxide gel is improved blood flow in the brain. The blood flow improved mice’s learning ability to navigate their surroundings as tested with the Morris water maze test. The nitric oxide gel also protected against non-alcoholic fatty liver disease possibly from a decrease in triglycerides in the liver and lower cholesterol in the blood.
The study is published in the journal ACS Applied Materials & Interfaces.