Exploring the anti-neuroinflammatory potential of steroid and terpenoid-derived phytochemicals to combat Alzheimer's disease

Alzheimer's disease (AD) is an age-related progressive neurodegenerative disorder that significantly affects cognitive functions in a way that causes loss of memory, thinking, and behavior. Multiple studies revealed that neuroinflammation associated with AD is linked with the amyloid-beta deposition in the brain. Elevated levels of expression of cytokines, microglial activation, nuclear factor kappa B, and reactive oxygen species play roles in AD-related inflammatory processes. Indeed, effective therapeutic approaches are urgently required to develop therapeutic agents to prevent and treat AD. So far, many anti-AD drug candidates have failed in the clinical stages and currently available drugs only provide symptomatic treatment. In recent times, pharmacologically active phytochemicals have been found to possess promising anti-neuroinflammatory effects; therefore, these natural products can be useful in AD treatment. In this review, we have comprehensively discussed the role of neuroinflammation and the molecular processes altered by multiple steroid and terpenoid-derived phytochemicals in various AD-related neuroinflammatory pathways. Indeed, steroid and terpenoid-derived phytochemicals show important therapeutic activities, which can be useful in ameliorating and treating AD-related neurodegeneration.