Altitude-induced biochemical variations in Picrorhiza kurrooa from Uttarakhand

Picrorhiza kurrooa Royle ex Benth, commonly known as Kutki, is a high-altitude medicinal herb valued for its hepatoprotective and antioxidant properties. This study investigates the effect of altitude on the biochemical composition of P. kurrooa populations from three sites in Uttarakhand: Tungnath (3200 m asl), Baniyakund (2460 m asl), and Pothibasa (2200 m asl). Fresh rhizomes were collected, authenticated, and analyzed for primary and secondary metabolites, including proteins, soluble sugars, starch, proline, phenolics, tannins, and flavonoids. Results revealed a significant increase in soluble protein (67.39±5.9 mg/g fr.wt.), proline (18.50±0.52 µmol/g), phenolics (86.45±1.61 µg/ml GAE), and flavonoid content (29.8±0.52 µg QE/ml) in the Tungnath population compared to lower altitudes. Soluble sugars were also highest in Tungnath, while starch content decreased with altitude. The higher metabolite concentrations at elevated altitudes are attributed to environmental stress factors such as UV-B radiation and cold temperatures, promoting adaptive responses in the plant. These findings underscore the superior adaptability and pharmaceutical potential of high-altitude populations, particularly the Tungnath genotype. Conservation and sustainable cultivation practices are recommended to preserve this endangered species and reduce pressure on wild populations.