Variation in picrotin and picrotoxin content of Picrorhiza kurroa Royle ex Benth rhizomes from Garhwal Himalaya

Department of Botany, Department of Chemistry, D. S. B. Campus, Kumaun University,

Nainital-263 002, Uttarakhand

E-mail : geeta_k@rediffmail.com

High Altitude Plant Physiology Research Centre (HAPPRC), H. N. B. Garhwal University,

Srinagar Garhwal-246 174, Uttarakhand

Manuscript received online 18 August 2014, revised 04 September 2014, accepted 04 September 2014

Picrorhiza kurroa Royle ex Benth (Scrophulariaceae), commonly known as Kutki, is an important medicinal herb in the traditional ayurvedic system of medicine and has been used to treat various diseases. It is known to contain iridoid glycosides (picrotin and picrotoxin) which are found responsible for the medicinal effects of Kutki. This study addresses variability at active ingredients level among populations of rhizomes of Picrorhiza kurroa Royle ex Benth growing at two different altitudes of Garhwal Himalayas. The plants were collected from two different altitudes, viz. Tungnath (3600 m) and Pothivasa (2200 m) in Rudraprayag district of Garhwal Himalaya, Uttarakhand, India, and analyzed by HPLC (High Performance Liquid Chromatography). A considerable degree of variation in amount of active contents was observed. Picrotin and picrotoxin content was found highest in populations collected from Tungnath compared to Pothivasa suggesting that active content accumulation is directly correlated with altitudinal variation. The present study reveals that there is a remarkable variation in the amount of picrotin and picrotoxin content with increasing altitude.