The co-administration of quercetin and gallic acid nanocapsules exhibits a protective effect against aluminium chloride in the brain of animal model

Introduction: Aluminum (Al) is associated with the development of various neurological disorders, including Alzheimer's disease (AD), highlighting the need for materials with protective effects. This study investigated the protective effect of quercetin and gallic acid nanocapsules on brain damage caused by aluminum chloride. Materials and methods: Adult rats were chronically treated with aluminum chloride to generate a disease model. Gallic acid and quercetin were administered orally, both in free forms and as nanocapsules, to evaluate their protective effects. To assess oxidative stress, the levels of lipid peroxidation, total antioxidants, reduced glutathione, glutathione peroxidase, superoxide dismutase, catalase, and myeloperoxidase activity were measured. Brain tissue was also examined for structural abnormalities using hematoxylin and eosin staining. Results: Aluminum chloride treatment significantly increased oxidative stress and brain damage. However, treatment with a combination of gallic acid and quercetin, both in free (20 mg/kg and 50 mg/kg, respectively) and nanocapsule forms, effectively reduced these effects. Histological evaluation showed that co-treatment with quercetin and gallic acid nanocapsules significantly reduced aluminum-induced toxicity and preserved normal brain structure. The nanocapsule forms were more effective at lower doses (10 mg/kg) compared to the free forms. Conclusion: These findings suggest that quercetin and gallic acid nanocapsules can reduce the required therapeutic dose and limit the adverse effects of the free drugs. Nanocapsule formulations may enhance brain delivery and act as neuroprotective agents against aluminum-induced damage and the progression of Alzheimer’s disease. The encapsulated form of quercetin and gallic acid appears to be a promising protective agent in preclinical evaluations.