In the previous studies, the saponins extracted from natural products could improve cognitive deficits in SAMP8 mice [46], protect splenocytes and thymocytes in an ageing rat model induced by d-gal [33], and attenuate d-gal-induced ageing in rats by activating FOXO3a and Nrf2 pathways [43]. The gene discussed is FOXO3; the disease is Cognitive impairment.