The steadily growing life expectancy, contemporary lifestyles, and changing environmental circumstances are responsible for the rising prevalence of the processes leading to various illnesses. The death rate due to multiple ailments has increased worldwide. Over the years, it has become necessary to seek new treatments that may cure chronic diseases and other infectious disorders ^[1][2][1,2].

Picrorhiza is derived from the Greek language, which means “bitter” (picros) and “roots” (rhiza). Picrorhiza is a genus comprising two species (Picrorhiza scrophulariiflora Pennell and Picrorhiza kurroa (P. kurroa)  Royle ex Benth) of the family Plantaginaceae. Most species are found in nature at sites such as cliffs, crevices, and mountainsides. Picrorhiza kurroa Royle ex Benth is mainly found at an altitude of 3000–5000 m above sea level in the Himalayan ranges of Nepal, Pakistan, and India ^[3][4][4,5]. This plant grows on rocky slopes and organic and moist soils in the Himalayan region (Garhwal to Bhutan). It is also found in northern Burma, western China, and southeastern Tibet ^[4][5]. It is also grown in the central and eastern regions but is abundant in the northwestern region ^[3][4]. It is a well-established herbal medicine for many ailments, ranging from dyspepsia to hepatitis ^[5][6]. Traditional and modern medicine have used bitter extracts from the dried rhizomes of this plant as a purgative, brain tonic, stomachic, and antiperiodic to treat dyspepsia ^[6][7][8][7,8,9]. Many traditional herbs are known for their cooling, heating, or neutral properties. If the heat is reduced by a herb, it becomes known for its cooling properties. P. kurroa has a cooling effect and is used as an antipyretic, cardiotonic, laxative, antiasthmatic, and anthelmintic ^[9][10]. Bhandari et al. (2010), Rana et al. (2018), and Bhattacharjee (2013) provided local names and botanical descriptions of P. kurroa ^[10][11][12][11,12,13]. P. kurroa has been used to treat respiratory diseases, allergies, inflammatory conditions, fever, diarrhea, chronic scorpion stings, asthma, and liver-related diseases ^{[10][13][14][15]}[11,14,15,16]. Hepatoprotective effects against carbon tetrachloride, alcohol, isoniazid, paracetamol, amanita mushrooms, rifampicin, Plasmodium berghei, and aflatoxin B1 poisoning have been reported ^{[16][17][18][19][20][21][22]}[17,18,19,20,21,22,23]. Jaundice can be treated with P. kurroa ^[23][24]. The ethanolic extract contains 50–60 percent of two iridoid glycohepatosides in the ratio of 1:1.5, picroside-I, and kutkoside, which have been proven to have powerful hepatoprotective effects against miscellaneous hepatotoxins, including alcohol in preclinical studies. The active constituents of kutki consist of kutkoside and iridoid glycosides (IGs) (picroside I and II), which are primarily found in the rhizome and roots ^[24][25]. No major adverse effects have been reported for this plant. The diverse pharmacological activities of P. kurroa, a medicinally significant endangered plant, have led researchers to develop practical techniques for its in vitro mass multiplication ^[6][7][8][7,8,9]. The International Union for Conservation of Nature (IUCN) reported that this species should be protected under the rare endangered species (RET) category. Practical actions, such as in situ and ex situ conservation, are required to preserve this plant ^[25][26][26,27].

2. Ethnobotanical Properties of P. kurroa

Picrorhiza kurroa plants have a long creeping rootstock that is bitter and grows in rock crevices and moist, sandy soil. The plant’s leaves are oval, flat, and serrated. The flowers are pale purple or white, appear from June to August, and are borne on a tall spike. The plants are harvested manually from October to December. The morphological features of the plant are depicted in Figure 1. Traditional medicine is affordable and widely available in developing nations, and many people rely on it for their primary healthcare needs. In Ayurveda, P. kurroa is known as “kutki” or “Katuka” and has several health advantages recorded in both Samhitas (medical treatise of Ayurveda) ^[27][28]. Nighantu (an important treatise on ayurvedic herbs that mentions names of drugs from various sources, such as vegetables, minerals, and animals, and their synonyms, actions, and uses) examined and discussed the qualities and dosages of P. kurroa for treating various illnesses ^[28][29]. Adarsa Nighantu also explains how to properly use the herb’s root portion as the recommended daily dose ^[29][30]. Tibetan medical experts and non-specialists use this plant’s rhizomes to cure colds, coughs, skin diseases, liver diseases, fever, indigestion, jaundice, scorpion stings, hepatitis, and metabolic problems ^[30][31][31,32]. A brief botanical description of P. kurroa is shown in Table 1.