According to a study published in the journal Cell Metabolism, researchers have discovered that a new drug could assist in weight loss that stays away. The drug, which has so far, only been tested in mice, increases sensitivity to the hormone leptin, which is a natural appetite suppressant found in the body. The findings will affect the development of new treatments for combating obesity in humans.
Senior author of the study, George Kunos from the National Institute on Alcohol Abuse and Alcoholism, explained:
“By sensitizing the body to naturally occurring leptin, the new drug could not only promote weight loss, but also help maintain it. This finding bodes well for the development of a new class of compounds for the treatment of obesity and its metabolic consequences.”
Even though leptin suppresses appetite, taking leptin supplements alone has so far proven ineffective in reducing people’s body weight. Researchers believe that this is due to desensitization of the hormone, since leptin is still present yet the body is unable to respond to it.
The reasons for this desensitization still remain uncertain, although researchers hypothesize that cannabinoid receptors might be involved that control the body’s hunger feelings that is generated by marijuana and other naturally occurring cannabinoids.
A more effective weight loss could be achieved by blocking these receptors, instead of providing excess leptin. Based on the fact that consumption of marijuana produces hunger feelings, researchers have developed anti-obesity drugs that target this cannabinoid receptor type 1 (CB1R). In 2006, one such CB1R-binding drug called rimonabant was sold in Europe, but its circulation was revoked a few years later, because the drug was found to cause serious psychiatric side effects, such as anxiety, depression and suicidal thoughts.
Kunos and his team tried to minimize these side effects in a CB1R-targeting drug they developed earlier. Their drug did not enter the brain as easily as rimonabant, but it proved less effective in reducing weight and improving metabolic health, which may be due to its specific mode of action.
Their new study consisted of testing a new compound, JD5037, which targets CB1R without penetrating the brain by suppressing the appetite of obese mice, caused weight loss. The team observed that the compound even managed to partially improve metabolic health by re-sensitizing mice to the appetite-suppressing hormone leptin. Most significantly, the drug caused no signs of anxiety or other behavioral side effects in the test mice.
Kunos concludes:
“Obesity is a growing public health problem, and there is a strong need for new types of medications to treat obesity and its serous metabolic complications, including diabetes and fatty liver disease.”
Written by Petra Rattue