Aluminum and Cadmium Content in Two Commercial Spirulina Supplement and Related Physiological and Histopathological Alterations: In Vivo Study

Spirulina is a widely recognized nutritional supplement, yet the safety and quality of commercial products remain a concern due to potential heavy metal accumulation. This study investigated the heavy metal content, physiological, and histopathological impacts of two commercial Spirulina brands from the Egyptian market on Sprague Dawley rats. Commercial Spirulina and Lab-grown Spirulina (LGC) were analyzed for heavy metal content. Physiological effects were assessed by measuring liver and kidney function markers, lipid peroxidation (MDA), and hematological parameters. Histopathological changes in liver and kidney tissues were examined. LGC was devoid of detectable toxic heavy metals, while commercial brands exhibited alarmingly high concentrations of cadmium (2200 ± 560 mg/kg and 1900 ± 679 mg/kg, respectively) and elevated aluminum. These levels significantly exceeded international safety limits. In vivo, Brand A induced severe dose-dependent histopathological alterations in rat livers and kidneys, including cytoplasmic vacuolization and necrosis, contrasting with the mild changes observed with Brand B and normal histology in the control. Hematological analysis revealed a significant reduction in red blood cell parameters by Brand B, indicative of anaemia, likely linked to its high cadmium content. Both commercial brands demonstrated antioxidant properties by reducing MDA levels, with Brand B showing superior efficacy.