Molecular mechanisms of neuroprotective offerings by rosmarinic acid against neurodegenerative and other CNS pathologies

Rosmarinic acid (RA) is a natural phenolic compound present in culinary herbs of the Boraginaceae, Lamiaceae/Labiatae, and Nepetoideae families. While the medicinal applications of these plants have been known for ages, RA has only been relatively recently established as an effective ameliorative agent against various disorders including cardiac diseases, cancer, and neuropathologies. In particular, several studies have confirmed the neuroprotective potential of RA in multiple cellular and animal models, as well as in clinical studies. The neuroprotective effects mediated by RA stem from its multimodal actions on a plethora of cellular and molecular pathways; including oxidative, bioenergetic, neuroinflammatory, and synaptic signaling. In recent years, RA has garnered tremendous interest as an ideal therapeutic candidate for treating neurodegenerative diseases. This review first briefly discusses the pharmacokinetics of RA and then proceeds to detail the neuroprotective mechanisms of RA at the molecular levels. Finally, the authors focus on the ameliorative potential of RA against several central nervous system (CNS) disorders, ranging from neuropsychological stress and epilepsy to neurodegenerative diseases such as Alzheimer's disease, Huntington's disease, Parkinson's disease, Lewy body dementia, and amyotrophic lateral sclerosis.