Design, synthesis and biological evaluation of triazole-oxadiazole conjugates for the management of cognitive dysfunction.

Acetylcholinesterase has been a promising target for the development of putative therapeutics against cognitive decline. The deleterious effect of oxidative stress on the learning and memory paradigms of an individual has also been well documented. In view of this, the present study demonstrates the design, synthesis and pharmacological evaluation of triazole-oxadiazole conjugates. Eighteen novel hybrids (6-23) have been synthesised by employing suitable synthetic procedures and characterized by various spectral and elemental techniques. Further these synthesised compounds were evaluated against behavioural alterations using step down passive avoidance and escape learning protocol at a dose of 0.5 mg/kg with reference to the standard, donepezil. All the synthesised compounds were evaluated for their in vitro acetylcholinesterase (AChE) inhibition at five different concentrations using mice brain homogenate as the source of the enzyme. Biochemical estimation of markers of oxidative stress (lipid peroxidation, superoxide dismutase, glutathione and catalase) has also been carried out to assess the role of synthesised molecules on the oxidative damage induced by scopolamine. The compounds 13, 17 and 23 displayed appreciable activity towards acetylcholinesterase inhibition. These compounds also decreased scopolamine induced oxidative stress, thus serving as promising leads for the amelioration of oxidative stress induced cognitive decline. The molecular docking study performed to predict the binding mode of the compounds also suggested that these compounds bind appreciably to the amino acids present in the active site of the recombinant human acetylcholinesterase (rhAChE). The results indicated that these compounds could be further traversed as inhibitors of AChE and oxidative stress for the treatment of cognitive dysfunction.