ACS: Discoveries of hormones related to weight and appetite in the ‘90s
helped spur a search for obesity treatments targeting those hormones—
with disappointing results. Now scientists are taking a new tack that
could finally yield promising treatments, according to a story in Chemical & Engineering News (C&EN) that was produced in collaboration with the American Chemical Society’s open-access journal ACS Central Science. C&EN is the weekly newsmagazine of ACS.
Jyoti Madhusoodanan, a contributing editor at C&EN, reports that
early attempts to therapeutically target leptin and ghrelin — which
suppress and stimulate appetite, respectively — were mostly ineffective.
But the hormones’ discoveries paved the way to a deeper understanding
of the chemistry of hunger. Scientists have found that in addition to
leptin and ghrelin, many other factors contribute to eating habits.
Protein sensors in the stomach, for example, sense stretch, pressure and
volume changes when a person eats, and create a sense of fullness.
Neurotransmitters in the brain, including dopamine, serotonin and
norepinephrine, also tweak people’s feelings of hunger and satiety.
Recognizing the role of the brain in weight gain, researchers
developed newer therapies, approved in 2013 and 2014, to target
individual neuronal signaling molecules. But to further improve obesity
treatments, drugs will most likely need a more complex approach, given
the multiple factors involved in hunger. So researchers are now trying
combination therapies to better regulate various parts of the body’s
appetite control system. A few more years of research could ultimately
bear out this strategy — or help redirect the field yet again.