Neuroprotection by Flaxseed Oil in a Model of Hippocampal Injury Induced by Trimethyltin Involves Purinergic System Modulation

A large body of evidence suggests that flaxseed oil (FSO), one of the richest sources of essential omega-3 fatty acids, has neuroprotective properties. Purinergic signaling plays a crucial role in pathophysiological processes in the nervous system. There is a lack of evidence regarding the effects of FSO on the purinergic system under both physiological and neurotoxic conditions. Here we report the effects of dietary FSO consumption in a rat model of trimethyltin (TMT) intoxication. Exposure to TMT selectively induces hippocampal neuronal damage and glial reactivation associated with oxidative stress and neuroinflammation, causing severe behavioral impairments. When administered orally (1 mL/kg) before and during TMT intoxication (single dose 8 mg/kg, i.p.) to female Wistar rats, FSO effectively prevented the behavioral disturbances induced by TMT. FSO selectively increased CAT-mRNA level in both healthy and TMT-intoxicated animals, while preventing TMT-induced upregulation of Nrf2, NF-κB, and GPx1 without affecting SOD2 or Gsr-mRNA levels. FSO prevented microgliosis, microglial NTPDase1-eN upregulation, and the increase in purinergic receptors involved in microglial reactivity. Pretreatment with FSO in TMT-intoxicated rats maintained the activity and expression of NTPDase1 at control level, while the activity and expression of eN and ADA were increased. FSO upregulated eN, A₁R, A_2BR, A₃R, ADA, and NGF, while downregulating NTPDase1, A_2AR, and ENT1 in TMT-intoxicated rats. This suggests complex modulation of purinergic signaling, particularly the adenosine system. These findings may contribute to a better understanding of the effects of FSO, highlighting the impact of the dietary intake of this oil on the brain.