Design, Synthesis, and Pharmacological Screening of Pyridazinone Hybrids as Anticonvulsant Agents

A series of new hybrid benzimidazole containing pyridazinones derivatives were designed and synthesized in accordance with the pharmacophoric requirements essential for the anticonvulsant activity. The synthesized compounds were evaluated for anticonvulsant activity on mice by the gold standard maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ)-induced seizure models. Among the compounds tested, SS-4F showed significant anticonvulsant activity in both the screens with ED₅₀ values of 25.10 and 85.33 mg/kg in the MES and scPTZ screens, respectively. Compound SS-4F emerged as safer and effective anticonvulsant due to its several-fold higher protective indices. Further, the gamma-aminobutyric acid (GABA) estimation result showed a marked increase in the GABA level (1.7-fold) as compared to the control, which was further confirmed by good binding properties with the GABA_A receptor.