Effects of anthocyanins on the modulation of neuroinflammation: a systematic review of <i>in vivo</i> studies

Inflammation in the central nervous system (CNS) is involved in the pathophysiology of several neurological and psychiatric diseases. In this regard, anthocyanins - natural flavonoids belonging to a group of polyphenols - stand out for their antioxidant, anti-inflammatory, and neuroprotective activities. This systematic review aimed to answer the questions "What are the impacts of anthocyanins on modulating neuroinflammation <i>in vivo</i>?" and "What are the possible molecular mechanisms involved in the effects of anthocyanins on neuroinflammation?". The search was conducted in the PubMed, Scopus, and Embase databases, and the risk of bias was assessed using SYRCLE. Data analysis followed PRISMA guidelines. Eleven studies conducted in animal models, evaluating the effects of purified or standardized anthocyanins on neuroinflammation, were included. The dose used ranged from 2 to 630 mg/kg of body weight per day and the duration of the treatment varied from 1 day to 20 wks. The main results identified reduced IL-1β, IL-6, TNF-α, TLR4, NF-κB, NLRP3, MAPK and COX-2. These findings were accompanied by antioxidant effects, reduced microglial activation and apoptosis, and cognitive enhancement, highlighting the potential of anthocyanins in controlling neuroinflammation and providing support for the development of future studies. PROSPERO (CRD420251061825).