Impact of monosodium glutamate-induced obesity on learning, memory, and DNA damage: Sex-based comparative study in rats

Abstract

Obesity is a global health crisis linked to numerous adverse outcomes including cardiovascular disease, type 2 diabetes, cancer and cognitive decline. This study investigated the sex-specific effects of monosodium glutamate (MSG)-induced obesity on learning, memory, anxiety-like behavior, oxidative stress, and genotoxicity in rats. In 32 neonatal Wistar albino rats, subcutaneous MSG injections were administered to induce obesity. Both male and female obese rats displayed significant abdominal fat accumulation, with a more pronounced increase in females. Cognitive assessments using the Morris water maze test revealed substantial impairments in learning and memory in both sexes, although no significant sex-related differences were observed. Anxiety-like behavior remained unaffected by obesity in both sexes, as indicated by behavioral tests. Oxidative stress in the hippocampus, measured by total oxidant and antioxidant levels, did not show significant alterations. However, the study found genotoxic effects in female obese rats, indicated by DNA damage, whereas male rats did not exhibit such effects. The results suggest that MSG-induced obesity negatively impacts cognitive function and causes genotoxicity, particularly in females, highlighting the potential sex-specific vulnerabilities in obesity-related pathologies. This research provides valuable insights into the cognitive and genetic consequences of obesity, with implications for understanding complex biological mechanisms across sexes.