Lycopene Supplementation Attenuates Oxidative Stress, Neuroinflammation, and Cognitive Impairment in Aged CD‑1 Mice

The carotenoid pigment lycopene (LYC) possesses several properties, including antioxidative, anti-inflammatory, and neuroprotective properties. This study examined the effects of dietary supplementation with LYC on age-induced cognitive impairment, and the potential underlying mechanisms. Behavioral tests revealed that chronic LYC supplementation alleviated age-associated memory loss and cognitive defects. Histological and immunofluorescence-staining results indicated that LYC treatment reversed age-associated neuronal damage and synaptic dysfunctions in the brain. Additionally, LYC supplementation decreased age-associated oxidative stress via suppression of malondialdehyde levels, which increased glutathione, catalase, and superoxide dismutase activities and the levels of antioxidant-enzyme mRNAs, including those of heme oxygenase 1 and NAD-(P)-H–quinone oxidoreductase-1. Furthermore, LYC supplementation significantly reduced age-associated neuroinflammation by inhibiting microgliosis (Iba-1) and downregulating related inflammatory mediators. Moreover, LYC lowered the accumulation of Aβ1–42 in the brains of aged CD-1 mice. Therefore, LYC has the potential for use in the treatment of several age-associated chronic diseases.