Medicinal Plants and Bioactive Phytochemicals Targeting Neuroinflammation: Molecular Mechanisms, Preclinical Evidence and Translational Challenges

Abstract

Neuroinflammation is the inflammatory response within the central nervous system which is linked to many neurological disoders. These disorders include Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, ischemic stroke, among others. Short-term reaction to inflammation within the central nervous system has a contribution to the balance of neural homeostasis and protection of tissues but once the neuroinflammation is persistent, it may lead to the production of inflammatory mediators in excess, oxidative stress, and gradual neuronal damage. Increasing evidence suggests that persistent triggering of microglia and astrocytes, and also the disruption of signaling cascades like nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and NLRP3 inflammasome pathways, plays major role in the progression of neurodegenerative diseases. A lot of attention has been given to medicinal plants as a therapeutic agent that has prospects due to their wide range of phytochemicals and multi-target pharmacological effects. Many plant-based compounds such as curcumin, epigallocatechin-3-gallate, ginsenosides, withanolides, and bacosides have shown properties of anti-neuroinflammation and neuroprotection by inhibiting inflammatory signaling pathways, reducing microglial activation, reduction of oxidative stress, and increasing support for neuron survival. This review gives an in-depth review of medicinal plants with anti-neuroinflammatory properties, focusing on their bioactive compounds, mode of action, and clinical applications in neurological disorders. The current challenges, limitations and future research viewpoint relating to the clinical application of medicinal plant compounds are discussed. The findings show that medicinal plants are potential treatment options for neuroinflammatory disorders.