A new clinical study used functional Magnetic Resonance Imaging (fMRI) technology to look at the effects of short term supplementation with Zembrin (from HGH Pharmaceuticals, Ltd.) and the reduction of anxiety-related activity in the amygdala and its associated anxiety circuitry within two hours of administration (Neuropsychopharmacology. 2013 Dec;38(13):2708-16). The study found that Zembrin has the potential to help in the management of stress. Zembrin is the first patented, standardized and clinically studied extract of the South African plant Sceletium tortuosum.

In the double blind, placebo-controlled crossover trial, 16 healthy participants were scanned during performance in a perceptual-load and an emotional-matching task. Amygdala reactivity to fearful faces under low perceptual load conditions decreased after a 25 mg dose of Zembrin. Follow-up analysis on the emotion-matching task showed that amygdala-hypothalamus coupling was also reduced. The results demonstrated for the first time, S. tortuosum on the threat circuitry of the human brain.

"This study is the first of its kind to directly examine the effects of these types of compounds on brain activity. It further supports the science on the mechanisms of action for Zembrin, and has pioneered the use of brain-imaging technology to evaluate and validate the activity of a plant used for centuries by the San people of southern Africa," said Barbara Davis, director, medical and scientific affairs at PLT Health Solutions, marketer of Zembrin.