Abstract

Myocardial dysfunction, a major component of sepsis-induced multiorgan failure, contributes to the production of massive amounts of pro-inflammatory cytokines. Nitric oxide (NO) is known to act as a precursor of free radicals in inflammation. This research was conducted to assess the effect of aminoguanidine (AG) on lipopolysaccharide (LPS)-induced heart injury. 50 male rats were categorized into five groups (n = 10): (1) control, (2) LPS, (3) LPS-AG50, (4) LPS-AG100, and (5) LPS-AG150. LPS (1 mg/kg) was injected for 5 weeks, and AG (50, 100 and 150 mg/kg) was injected 30 min prior to LPS administration. All drugs were injected intraperitoneally. LPS-evolved cardiovascular toxicity was indicated by the augmentation in the level of nitric oxide (NO) metabolites, interleukin (IL)-6 and malondialdehyde (MDA), as well as reduced contents of total thiol groups, catalase (CAT), and superoxide dismutase (SOD) activity in serum, heart, and aortic tissues. In AG treated groups, noxious effects of LPS were not observed in the serum and harvested tissues. AG reduced MDA, NO metabolites, and IL- 6 and increased total thiol, CAT, and SOD activity in the heart, aorta and serum. As an inhibitor of inducible NO synthase (iNOS), AG further reduced LPS-induced oxidative stress and inflammation, hence considered as cardioprotective.