Three medicinal Corydalis species of the Himalayas: Their ethnobotany, pharmacognosy, phytochemistry and pharmacology

Herbal medicines including the scholarly Bhutanese Sowa Rigpa medicine (BSM) contribute significantly to primary health care services and play a considerable part in modern drug discovery. BSM, which was integrated with modern health care system in 1967, currently uses more than 200 species of medicinal plants including three closely related members of the Corydalis species; Corydalis calliantha, C. crispa, and C. dubia. Maintaining the quality of these medicinal plants has been always challenging due to adulterants and also due to lack of traditional quality control parameters that could distinguish closely related species. Therefore there is an urgent need to develop reliable analytical methods and quality parameters. Given the significant medicinal properties attributed to the three Corydalis species which are extensively used in BSM, a thorough literature review was performed to investigate their existing quality control parameters including: 1) morphological assessment, 2) habitat and ecological evaluation, 3) macroscopical and microscopical examination, 4) physiochemical limit setting and comparative high-performance thin layer chromatography (HPTLC) profiling, and 5) phytochemical and biological activities. The study revealed that there are distinct species-specific features including ecological adaptation, micromorphology, anatomy, phytochemical values and HPTLC profiles presented by each Corydalis species, and that these quality parameters support traditional quality screening processes in BSM.