Fisetin prevents the aging-associated decline in relative spectral power of α, β and linked MUA in the cortex and behavioral alterations

Mental health in old age is of great concern due to the increased incidence of neurological and psychiatric diseases. With age, probability of cognitive and behavioral deficits increase and the prognosis deteriorates. Although a few in vitro studies have reported that flavonoid fisetin is beneficial for healthy aging, its effect on deteriorating mental health with aging in vivo is very limited and poorly understood. The brain aging is physiologically characterized by electroencephalograph (EEG) wave frequency, power, and distribution. Brain oscillatory waves from neural tissue get altered by various sensory-cognitive inputs. Besides, the fast-wave α(8-12 Hz)- and β(12-28 Hz)-oscillations are associated with coordination and indeed deal with complex behavioral performances. Therefore, the effect of fisetin supplementation on age-associated EEG mean cortical spectral power in α- and β-oscillations, multi-unit activity (MUA) count were studied in vivo which was not addressed so far. Besides, age-associated cognitive and behavioral alterations were also studied. The relative spectral power of α and β declined along with the MUA count in aged rats compared to young. However, supplementing fisetin for four weeks has improved relative α-power, β-power, and MUA count in aged rats. Also, fisetin supplemented aged rats showed significantly improved cognitive and behavioral performances than aged controls. These findings demonstrated the relative cortical spectral power in α-, β-oscillations, and MUA count change in aged rats and that some of these changes and behavioral alterations may be partly as a result of oxidative stress, which was prevented significantly in fisetin supplemented aged rats. Thus, fisetin boosted mental health in the aged animals.

Keywords: Aging; Fisetin; Morris water maze; Multiple-unit activity; Open-field test; Relative spectral α-power; Relative spectral β-power.