7,8-dihydroxyflavone (7,8-DHF) is a synthetic flavonoid that was initially discovered in a study screening for small molecules that could activate a particular receptor known as tropomyosin-related kinase B (TrkB), because the peptide produced in the human body that acts on this receptor, called brain derived neurotrophic factor (BDNF), could not be used due to poor absorption into the brain. 7,8-DHF was found to be a potent mimic of BDNF able to act on TrkB in a similar manner. This means that 7,8-DHF could theoretically cause similar effects as BDNF in the brain, and in theory be more therapeutically useful due to its better absorption and ability to cross the blood-brain barrier.
When the TrkB receptor is activated, neurons tend to experience growth and protective effects. The growth tends to affect the dendrites of the neuron which reach out into the synapse to communicate with subsequent neurons, and 7,8-DHF has shown an ability to promote the growth of these dendrites into the synapse to help restore communication between neurons in animal models of cognitive decline (Alzheimer's and aging being researched). Some other supplements such as bacopa monnieri and polygala tenuifolia tend to work via activating this receptor via releasing BDNF in the brain.
There is a possible nootropic use of this flavonoid in otherwise healthy subjects, but the cognitive benefits seen in cognitively unwell rodents may not correlate well to healthy subjects. The evidence to support its benefits in cognitive enhancement in healthy rodents is mixed, and no human evidence exists at all.
Due to 7,8-DHF being a simple and effective activator of TrkB which can cross the blood-brain barrier, it will likely continue being researched for its cognitive effects.