CB1 Receptor Antagonists for Weight Loss

Cross-references: Cannabinoid Receptors

The CB1 receptor is responsible for the appetite stimulating properties of the endocannabinoids. The endocannabinoid system dates back almost 4000 years when the therapeutic and psychotropic actions of Cannabis sativa (marijuana) were first documented in India. Among the actions attributed to this plant, the stimulation of hunger and appetite has been widely recognized. Constitutive elements of the endocannabinoid system are the cannabinoid receptors.

The CB1 receptor, in particular, is responsible for the orexigenic (appetite-stimulating) properties of the endocannabinoids. It is expressed in several organs involved at both the central and periopheral levels in the control of food intake and energy metabolisms, such as the hypthalamus, gastrointestinal tract and adipose tissues.

Endocannabinoids are usually produced and immediately released after an influx of calcium ions into a nerve terminal during depolarization. They activate CB1 receptors located presynaptically, inducing a retrograde suppression of neurotransmitter release and, in this way, modulate the action of several neurotransmitters or hormones, including those involved in the central control of energy balance.

Companies such as Sanofi-Aventis are developming new drugs aimed at antagonizing the CB1 receptor as potential anti-obesity compounds, such as rimonabant which are in phase III clinical trails. AVENTIS PHARMACEUTICALS INC. has filed for patents on a combination of a CB1 receptor antagonist and sibutramine. See US Patent Pub 20050032774

Companies doing Cannabinoid research: See GW Pharmaceuticals