Antioxidant, anti-inflammatory and cytoprotective effects of crocin, a bioactive constituent of saffron, in Alzheimer's and Parkinson's diseases with a focus on molecular mechanisms: A systematic review.

Objective: This study assessed the neuroprotective effects of crocin one of the main bioactive compounds of saffron, in Alzheimer's and Parkinson's diseases, by focusing on its anti-oxidative, anti-inflammatory, and cytoprotective properties. Materials and Methods: models of Alzheimer's and Parkinson's diseases. Using three online literature databases (PubMed, Scopus, and Google Scholar), we identified studies describing the neuroprotective effects of crocin in Alzheimer's and Parkinson's diseases. A literature search was carried out using a combination of keywords such as crocin, Alzheimer's disease, Parkinson's disease, antioxidant, anti-inflammatory, and cytoprotective. Papers were identified to describe the neuroprotective effects of crocin from 2013 until 2024. Results: The total number of articles included in the present review is 28. Reducing reactive oxygen species (ROS) and malondialdehyde (MDA) and increasing superoxide dismutase (SOD) levels indicate the anti-oxidant effects of crocin. Crocin can show anti-inflammatory activities via decreasing tumor necrosis factor-alpha (TNF-α) and interleukin levels. Crocin can display cytoprotective effects via down-regulation of p- extracellular signal-regulated kinase (ERK)1/2, and augmentation of phosphoinositide 3-kinases (PI3K)/Akt/ mammalian target of rapamycin (mTOR) signaling pathway activity. Conclusion: Finally due to a noticeable efficacy of crocin, it is suggested that crocin can be used as a suitable neuroprotective agent against Alzheimer's and Parkinson's diseases.