ProcognitivePotential of Neuroprotective Triazine5‑HT₆ Receptor Antagonists Tested on Chronic ActivityIn Vivo in Rats: Computer-Aided Insight into the Role of Chalcogen-Differenceson the Pharmacological Profile

Among serotonin receptors, the 5-HT₆ subtype is an important protein target and its ligands may play a key role in the innovative treatment of cognitive disorders. This study aimed to extend the body of preclinical research on two naphthyl-derived methylpiperazine-1,3,5-triazine analogues with thioether (<b>WA-22</b>) or Se-ether (<b>PPK-32</b>) linkers, the newly described compounds having high affinity and selectivity for 5-HT₆ receptors and drug-like parameters in vitro. Thus, crystallography-supported deeper insight into their chemical properties, the comparison of their neuroprotective and pharmacokinetic profiles, and especially their impact on memory disturbances after chronic administration to rats were investigated. As a result, the chronic administration of <b>WA-22</b> completely reversed <b>(+)MK-801</b>-induced memory disturbances evaluated in the novel object recognition test (NORT) in rats. The pharmacokinetic and biochemical results support the notion that this 1,3,5-triazine 5-HT₆ receptor ligand could offer a promising therapeutic tool in CNS-related disorders. The selenium compound <b>PPK-32</b>, with a similar range of activity at acute administration, has shown even broader neuroprotective profiles, especially at the genetic level. However, for therapeutic use, its weaker pharmacokinetics (stability), which is a probable limit for action upon chronic administration, would require improvement, e.g., by an appropriate formulation.