Curcumin Nanoformulations For Neurological and Psychiatric Disorders: Delivery Strategies, Preclinical Evidence and Translational Prospects

Abstract

Background: Curcumin has antioxidant, anti-inflammatory, and anti-aggregation properties relevant to neurological and psychiatric disorders. However, poor water solubility, instability, rapid metabolism, and low oral bioavailability limit its brain exposure. Nanoformulaitons and intranasal delivery offer potential ways to overcome these barriers.

Objective: To review how curcumin nanoformulations improve brain delivery, assess preclinical and clinical evidence in neurological and psychiatric disorders, and identify evidence relevant to adolescents.

Data Source: Targeted searches of PubMed, ScienceDirect, Google Scholar, and relevant journal archives using combined terms related to curcumin, nanoformulations, neurodegenerative diseases, Alzheimer’s disease, epilepsy, cognition, and blood-brain barrier. Additional searches addressed children and adolescents. Relevant studies were synthesised narratively. Primary studies were classified according to brain curcumin measurement and inclusion of free-curcumin comparators and empty-carrier controls.

Data Synthesis: The review examines the delivery barriers and strategies involving liposomes, lipid and polymeric nanoparticles, protein-based carriers, nanoemulsions, exosomes, and intranasal administration. Selected preclinical studies demonstrated nanoformulations markedly increased curcumin brain exposure. Intranasal lactoferrin nanoparticles produced approximately 3.2-fold higher brain curcumin exposure than an intranasal suspension in rats. Intravenous nanostructured lipid carriers achieved measurable cerebral exposure when free curcumin was undetectable. However, many studies inferred brain delivery from behavioural or biochemical improvements rather than directly measuring unchanged curcumin. Some also lacked free-curcumin comparators or empty-carrier controls, limiting attribution of benefits to the formulation. Human findings remain limited and inconsistent, with insufficient evidence to establish adolescent-specific efficacy or safety.

Conclusion: Curcumin nanoformulations show preclinical promise, but clinical benefits remain unproven, particularly in adolescents. Priorities include measuring unchanged curcumin in brain tissue and cerebrospinal fluid, incorporating appropriate comparator and carrier controls, and conducting product-specific clinical trials with adequate safety monitoring. These steps are essential to determine whether improved delivery translates into meaningful patient benefit.