Isolation and evaluation of rhoifolin: an anxiolytic flavonoid from <i>Citrus paradisi</i> Macfayden var. <i>redblush</i> leaves

<i>Citrus</i> species have a history of use in treating neurological conditions like insomnia, anxiety, and nervousness, though these claims lack exhaustive validation. This study evaluated the anxiolytic activity of <i>Citrus paradisi</i> Macfayden var. redblush leaves, aiming to isolate and characterise the bioactive constituent. Four leaf extracts (petroleum ether (60-80 °C), chloroform, methanol and aqueous) were evaluated for anxiolytic activity using elevated plus maze (EPM) in mice. The methanol extract showed anxiolytic activity and was subjected to bioactivity guided isolation using solvent partitioning, column chromatography and preparative HPLC to isolate the anxiolytic compound, CP-1, characterised as rhoifolin (based on spectroscopic analysis). Rhoifolin, at 0.705% w/w in leaves, was confirmed as anxiolytic compound through additional tests (light-dark box and social interaction tests) and holds promise as a potential treatment for anxiety disorders.