Hydroxytyrosol Decreases LPS- and α-Synuclein-Induced Microglial Activation In Vitro

Abstract

Neuroinflammation is a common feature shared by neurodegenerative disorders, such as Parkinson’sdisease(PD),andseemstoplayakeyroleintheirdevelopmentandprogression. Microglia cells, the principal orchestrators of neuroinflammation, can be polarized in different phenotypes, which means they are able to have anti-inflammatory, pro-inflammatory, or neurodegenerative effects. Increasing evidence supports that the traditional Mediterranean dietary pattern is related to the reduction of cognitive decline in neurodegenerative diseases. A considerable intake of plant foods, fish, and extra virgin olive oil (EVOO), as well as a moderate consumption of red wine, all characteristicoftheMediterraneandiet(MD),arebehindtheseeffects. Thesefoodsareespeciallyrich in polyphenols, being the most relevant in the MD hydroxytyrosol (HT) and their derivatives present in EVOO, which have demonstrated a wide array of biological activities. Here, we demonstrate that HT is able to reduce the inflammation induced by two different stimuli: lipopolysaccharide and α-synuclein. We also study the possible molecular mechanisms involved in the anti-inflammatory effectofHT,includingthestudyofnuclearfactorkappaB(NF-κB),mitogen-activatedproteinkinases (MAPKs), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and inflammasome. Our data support the use of HT to prevent the inflammation associated with PD and shed light into the relationship between MD and this neurological disorder.