Weight-Loss Drugs Shown to be Harmful to Brain

The Endocannabinoid System is a physiological system that blocks hunger similar to smoking tobacco

A drug from a new class of weight-loss treatments disrupted wiring needed for brain development in young mice, American researchers said, raising concerns about using such medications in children.

Mark Bear and colleagues at the Massachusetts Institute of Technology studied the effects of a chemical that suppresses appetite by blocking cannabinoid receptors in the brain, the same brain mechanisms that make people hungry when they smoke marijuana.

“I think that the cautionary note is that these mechanisms play an important role in … brain development,” said Bear.

The Endocannabinoid System (EC System) is a physiological system of cannabinoid receptors and corresponding chemical messengers that is believed to play an important role in regulating body weight and glucose and lipid metabolism. The EC System also plays a role in tobacco dependence.

The chemical messengers of the EC System are endocannabinoids (ECBs) which bind to and activate the cannabinoid (CB 1) receptors. CB 1 receptors are found in the brain as well as in some peripheral tissues of the body such as adipocytes (or “fat cells”) which are associated with lipid and glucose metabolism.

Through both this central and peripheral activity, the EC System helps to regulate food intake and energy expenditure. It is also involved in the body’s response to tobacco use.

Physiologically, the EC System is activated in response to stressful stimuli to help re-establish the normal steady state of the affected cells or tissues. Therefore, the effects of EC System activation are short-lasting, confined to those cells or tissues that have been subjected to stress or damage, and normally end once the organism has recovered from a transient “unbalanced” condition.