Neuropharmacological Activity of Passiflora incarnata : An Updated and Comprehensive Review of its Molecular Mechanisms

Passiflora incarnata is a worldwide ethnomedicinal species with sedative, anxiolytic, and anticonvulsant properties, among other neurological effects. Despite the importance of the topic and several articles published, there is a lack of documents that address an integrated and critical view of the mechanisms related to the neuropharmacological activities of the species. Therefore, this review aimed to update and compile articles on neuropharmacological mechanisms of P. incarnata, as well as to critically discuss the topic. The search included documents from three different databases. Its chemical composition includes flavonoids, alkaloids, organic acids, and benzoflavones, which collectively account for its broad neuropharmacological activity. Flavonoids such as vitexin, isovitexin, orientin, and chrysin are the predominant metabolites, while β-carboline alkaloids occur in smaller quantities but contribute to monoamine oxidase (MAO) inhibition. The presence of γ-aminobutyric acid (GABA) further supports its GABAergic modulatory potential. Furthermore, hydroethanolic and n-butanol extracts of P. incarnata enhance GABA receptor expression, increase melatonin levels, and prevent scopolamine-induced memory deficits, reflecting synergistic mechanisms underlying its sedative and nootropic effects. Additionally, chrysin exerts neuroprotective and antidepressant effects through modulation of GABA activity, inhibition of MAO-B, and regulation of apoptotic signaling. Other constituents, including benzoflavone fractions, have shown promise in mitigating withdrawal symptoms from alcohol, nicotine, and cannabinoids. The plant also exhibits anticonvulsant, anti-inflammatory, and antioxidant effects, potentially linked to flavonoids and amino acids. Collectively, P. incarnata is a valuable medicinal plant with multiple central nervous system actions mediated by complex phytochemical interactions. Moreover, its safety profile is favorable, with rare hypersensitivity reactions.