Loop-mediated isothermal amplification (LAMP) for quality control of Coscinium fenestratum: a colorimetric platform...

Coscinium fenestratum (Gaertn.) Colebr., commonly known as tree turmeric, is a critically endangered medicinal plant extensively used in Ayurveda and Siddha systems for treating metabolic disorders and various infectious diseases. Due to overexploitation and habitat loss, Coscinium fenestratum faces severe conservation threats, resulting in a scarcity of authentic raw material and frequent adulteration with morphologically similar species such as Anamirta cocculus. The present study reports the development and validation of an internal transcribed spacer (ITS) based loop-mediated isothermal amplification (LAMP) assay for rapid authentication of C. fenestratum and sensitive detection of A. cocculus adulteration. Species specific LAMP primers were designed targeting the variable regions of ITS sequence, and assay optimization identified 7 mM MgSO₄ and 1 M betaine as the optimal reagent concentrations. Colorimetric detection using hydroxy naphthol blue (HNB) dye enabled closed-tube visual detection with a violet to sky blue color transition upon amplification. The assay demonstrated 100 per cent specificity with no cross-reactivity between species and achieved a limit of detection of 0.05 per cent adulterant DNA. Analysis of ten market samples including bark and powdered bark specimens revealed 30 per cent adulteration in the tested samples. The developed LAMP assay requires minimal equipment, uses crude DNA extracts, and delivers results within 60 min, making it suitable for resource-limited laboratory settings. This rapid, sensitive, and user-friendly molecular tool enables reliable authentication and quality control of Ayurvedic medicinal raw materials.