Depression affects at least 350 million people around the world, yet almost two-thirds of patients don't respond to the medication prescribed by their doctors. Because of this, a possible may happen and it's only a matter of time before suicide rates skyrocket. In recent studies, it was discovered that inflammation plays a major role in the development of depression. This urged the researchers at the University of California- Davis to explore a new chemical to control the severe psychiatric disorder.
It was discovered that the experimental drug reacts to the same enzyme aimed by drugs made for inflammation-based diseases. According to Medical Daily, the drug works as an inhibitor of soluble epoxide hydrolase or sEH. This enzyme contributes to several diseases such as hypertension (high blood pressure), pain, cardiac hypertrophy (thickening of the heart), and several types of cancer.
Authors of the study explained that the samples of brains from dead patients who suffered from depression and schizophrenia show an elevated expression of sEH compared to those without the disease. An inhibitor of sEH is apparently a good target for antidepression.
How do you evaluate the effects of a depression drug in animals? That was the simple question acclaimed professor and lead author of the study Dr. Bruce Hammock asked before he began.
A past study funded by the National Institute for Mental Health analyzed the same path, except that it dealt with mood and anxiety disorders that affect one of every 6 people in their lifetime. The authors of the said study noticed that the improvement of animal models was the major challenge of the researchers. Dr. Scott J. Russo of Mt. Sinai and the authors he worked with in the study believes that the limited number of model animals can explain the scarceness of novel drugs, repubhub.icopyright.net reports.
One issue that researchers found difficult to handle was that patients suffering from depression exhibit a very wide range of symptoms. However, the symptoms that help researchers were the physiological response of the animals. Scientists used different kinds of stress to bring out the symptoms of depression in rodents with each stress exactly like the other. However, the mice's pituitary-adrenal axis reacted when the researchers repeatedly exposed them to social defeat as the depression-inducing stressor.
Researchers use the "resident-intruder" approach to test the mice since they are known to be very territorial. The researchers tested this method by placing smaller mouse in a cage of older mice that have already made the cage their home. After having a hard time with the older mice, the smaller mouse will show signs of social defeat even when it is already transferred in a new cage with mice of the same size and age. The mouse will act just like an anxious and scared human. It will also approach other rodents with caution which will usually result to them scampering away.
To examine an effective sEH inhibitor known as TPPU, Hammock and his team chose social defeat as their experimental protocol. They found that the mice without the sEH gene did not show any sign of any depression-like behavior after being exposed to social-defeat stress repeatedly. Also, they found that sEH protein was higher in important regions of the brain of those mice that were chronically stressed than the comparison mice.
The mice were pretreated with TPPU and it helped prevent depression-like behavior after being exposed to social-defeat stress or induced inflammation. TPPU showed a quick effect in controlling symptoms of depression in the mice.
