“The adipocyte-derived, anorectic hormone, leptin, was recently shown to owe part of its regulatory effects on appetite-regulating hypothalamic neuropeptides to the elevation of ROS levels in arcuate nucleus (ARC) neurons.

Leptin is also known to exert a negative regulation on hypothalamic endocannabinoid levels and hence on cannabinoid CB1 receptor activity.

Here we investigated the possibility of a negative regulation by CB1 receptor of leptin-mediated ROS formation in the ARC…

We conclude that CB1 activation reverses leptin-induced ROS formation, and hence possibly some of the ROS-mediated effects of the hormone, by preventing PPAR-γ inhibition by leptin, with subsequent increase of catalase activity.

This mechanism might underlie in part CB1 orexigenic actions under physiopathological conditions accompanied by elevated hypothalamic endocannabinoid levels.”