I've been reading about polygala tenuifolia, and look at this!
I am not sure yet how it does all this, but I'll keep reading and updating.
In Traditional Chinese Medicine, Polygala tenuifolia root is one of the most used herbs to support the brain and central nervous system. Traditionally it was often used to reduce forgetfulness and support brain performance during aging (i.e., it’s what we’d consider a nootropic today). It was also commonly used in formulas to support sleep and promote a calmer, more balanced mood. Preclinical research suggests it supports brain protection and repair processes and molecules (such as BDNF and NGF), counters chronic stress, supports sleep, and influences both adenosine signaling—a molecule involved in the sleep homeostatic drive—and GABA signaling—a neurotransmitter involved with relaxation at night and sleep.
"Cyclic adenosine monophosphate (AMP) phosphodiesterase inhibitors contained in Polygala tenuifolia WILLD. were identified as saponins and oleic acid."
"tenuifolia root extract contains the adenosine A 1 receptor antagonists"