Neuroprotective Benefits of Rosmarinus officinalis and Its Bioactives against Alzheimer’s and Parkinson’s Diseases

Neurodegenerative disorders (NDs) are conditions marked by progressively escalating inflammation that leads to the degeneration of neuronal structure and function. There is an increasing interest in natural compounds, especially those from pharmaceutical plants, with neuroprotective properties as part of potential therapeutic interventions. Thus, the rich bioactive content of the perennial herb rosemary (Rosmarinus officinalis) is thoroughly reviewed in this article, with an emphasis on its pleiotropic pharmacological properties, including its antioxidant, anti-inflammatory, and neuroprotective health-promoting effects. In addition, a comprehensive analysis of the existing scientific literature on the potential use of rosemary and its bioactive constituents in treating neurodegenerative disorders was also conducted. Rosemary and its bioactives’ chemical properties and neuroprotective mechanisms are discussed, focusing on their ability to mitigate oxidative stress, reduce inflammation, and modulate neurotransmitter activity. The role of rosemary in enhancing cognitive function, attenuating neuronal apoptosis, and promoting neurogenesis is outlined. Key bioactive components, such as rosmarinic acid and carnosic acid, are also highlighted for their neuroprotective act. The promising outcomes of the conducted pre-clinical studies or clinical trials confirm the efficacy of rosemary in preventing or alleviating Alzheimer’s and Parkinson’s diseases both in vitro (in cells) and in vivo (in animal models of NDs). From this perspective, the applications of rosemary’s bio-functional compounds and extracts in the food, cosmetics, and pharmaceutical sectors are also presented; in the latter, we discuss their use against neurodegenerative disorders, either alone or as adjuvant therapies. This paper critically evaluates these studies’ methodological approaches and outcomes, providing insights into the current state of the clinical research and identifying potential avenues for future investigation. All findings presented herein contribute to the growing body of literature and support the exploration of natural compounds as promising candidates for novel applications and neuroprotective interventions, paving the way for more applied scientific research.