Visha Chikitsa

The blood–brain barrier (BBB) is a highly selective component of the neurovascular unit that regulates the movement of substances between the systemic circulation and the central nervous system. Contemporary strategies for brain delivery include passive diffusion, carrier-mediated transport, receptor-mediated transcytosis, nanoparticle-based approaches, and intranasal delivery. Ayurveda describes nourishment, distribution, and movement within the body through concepts such as Doshas, Srotas, Agni, and Nyayas including Kedara-Kulya and Khale-Kapota. This narrative, integrative review examines these classical concepts alongside contemporary understanding of BBB structure and transport mechanisms, with the aim of developing a cautious interdisciplinary interpretative framework. Classical Ayurvedic sources and selected scientific literature were examined to identify conceptual correspondences, evidence gaps, and potential areas for future research. The review distinguishes classical descriptions from modern interpretations and hypothesis-generating analogies. Srotas may be considered a functional concept related to movement and distribution, while comparisons with specific vascular structures, cellular components, molecular dimensions, or membrane transport mechanisms remain interpretative rather than established equivalences. Similarly, the lipid-rich nature of Ghrita and the absorption of lipid-associated phytoconstituents may influence formulation-dependent solubilization, systemic absorption, and pharmacokinetics; however, these properties alone do not demonstrate BBB penetration or central nervous system exposure. Nasya may be interpreted in relation to contemporary intranasal drug-delivery pathways, whereas proposed mechanisms of Sirodhara involving central neurophysiological effects require further investigation. Thus, this framework identifies testable points of correspondence without claiming direct equivalence between Ayurvedic concepts and modern BBB mechanisms.