In vivo assessment of newly synthesized achiral copper(ii) and zinc(ii) complexes of a benzimidazole derived scaffold as a potential analgesic, antipyretic and anti-inflammatory

Abstract

Two new complexes of copper(II), [CuL₂], and zinc(II), [ZnL₂], with a tridentate –ONN′– Schiff base ligand (L), a bioactive scaffold derived from 2-aminobenzimidazole and 2-hydroxy-3-methoxybenzaldehyde, were synthesized and characterized using various spectroscopic techniques, viz, IR, ¹H and ¹³C NMR, EPR, HRMS, and elemental analysis and purity analysis using UPLC studies. Both the complexes are non-electrolytic by nature. The newly synthesized compounds were screened for acetic acid-induced analgesic and yeast-induced antipyretic activities in mice and carrageenan-induced paw edema in rats (anti-inflammatory). The results showed that the [CuL₂] compound (at 100 mg kg⁻¹ b.w) possessed potent anti-inflammatory activity whereas [ZnL₂] (at 50 mg kg⁻¹ and 100 mg kg⁻¹ b.w) exhibited significant analgesic activity when compared with standard drugs. Both the complexes have apparently moderate and nearly akin antipyretic activity.