Limonin as serotonin mimetic to protect from Alzheimer’s disease

Limonin (LM), a limonoid glycoside isolated from leaves, fruits, and seeds of citrus plants, belongs to the class of furanolactones [1]. Recently, LM has gained significant interest due to its multiple biological activities such as anti-inflammatory, antitumor, antimicrobial, and antifeedant activity. Lu et al. [2] demonstrated that pretreatment of LPS-induced microglial cells with LM substantially prohibited the formation of ROS and prevented the deposition of NO, PGE2, IL-1β, IL-6, and TNF-α [2]. Furthermore, LM significantly reduced the expressions of iNOS and COX-2 [3]. Their results indicated that LM inhibited inflammatory response through repressing the formation of ROS, accretion and discharge of cytokines, and activation of inflammatory mediators, suggesting its potential as a neuroprotective agent.