Influence of chronic caffeine on MDMA-induced behavioral and neuroinflammatory response in mice

Previous research suggests that chronic daily caffeine administration protects against brain injury in different animal models of neurodegenerative diseases, such as Parkinson's and Alzheimer's diseases, ischemic and traumatic brain injury, and allergic encephalitis. However, little is known about the effects of chronic caffeine administration on 3,4-methylenedioxymethamphetamine (MDMA)-induced neuroinflammation.

The present study examines whether chronic caffeine (10, 20, or 30 mg/kg, i.p, for 21 consecutive days) protects against MDMA-induced astrocytic and microglial activation in mice striatum, impairing its neuroinflammatory effects. Additionally, locomotor activity, sensoriomotor reflexes, body temperature, and anxiety were evaluated after caffeine injection on days 0 (basal), 7, 14, and 21 of the chronic treatment in order to assess possible behavioral alterations due to caffeine administration.

On day 22, mice pretreated with caffeine or saline received a neurotoxic regimen of MDMA (3 × 20 mg/kg, i.p., 2-h interval) or saline, and changes in body temperature were evaluated. Forty-eight hours after last MDMA or saline injection (day 24), the aforementioned behavioral parameters were investigated and microglia and astroglia activation to MDMA treatment was examined in the mouse striatum.

Caffeine (10 mg/kg) chronically administered completely prevented MDMA-induced glial activation without inducing physiological or behavioral alterations in any of the assays performed.

Chronic caffeine consumption at low doses exerts anti-inflammatory effects and prevents MDMA-induced neuroinflammation.