Fisetin as a caloric restriction mimetic protects rat brain against aging induced oxidative stress, apoptosis and neurodegeneration

Aim In the present study, attempts have been made to evaluate the potential role of fisetin, a caloric restriction mimetic (CRM), for neuroprotection in D-galactose (D-gal) induced accelerated and natural aging models of rat. Main methods Fisetin was supplemented (15 mg/kg b.w., orally) to young, D-gal induced aged (D-gal 500 mg/kg b.w subcutaneously) and naturally aged rats for 6 weeks. Standard protocols were employed to measure pro-oxidants, antioxidants and mitochondrial membrane potential in brain tissues. Gene expression analysis with reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to assess the expression of autophagy, neuronal, aging as well as inflammatory marker genes. We have also evaluated apoptotic cell death and synaptosomal membrane-bound ion transporter activities in brain tissues. Key findings Our data demonstrated that fisetin significantly decreased the level of pro-oxidants and increased the level of antioxidants. Furthermore, fisetin also ameliorated mitochondrial membrane depolarization, apoptotic cell death and impairments in the activities of synaptosomal membrane-bound ion transporters in aging rat brain. RT-PCR data revealed that fisetin up-regulated the expression of autophagy genes (Atg-3 and Beclin-1), sirtuin-1 and neuronal markers (NSE and Ngb), and down-regulated the expression of inflammatory (IL-1β and TNF-α) and Sirt-2 genes respectively in aging brain. Significance The present study suggests that fisetin supplementation may provide neuroprotection against aging-induced oxidative stress, apoptotic cell death, neuro-inflammation, and neurodegeneration in rat brain.