Ayurveda – Arka (root)
Arka consists of dried roots of calotropis procera (ait.) r. br. (fam. asclepiadaceae) found wild more or less throughout India.
sanskrit : ravi, bhanu, tapana
assamese : akand, akan
bengali : akanda, akone
english : madar tree
gujrati : aakado
hindi : aak, madar, akavana
kannada : ekka, ekkadagida, ekkegida
kashmiri : acka
malayalam : erikku
marathi : rui
oriya : arakha
punjabi : ak
tamil : vellerukku, erukku
telugu : jilledu
urdu : madar, aak
root-rough, fissured longitudinally, corky and soft, externally yellowish-grey while internally white, central core cream coloured, bark easily separated from xylem, odour, characteristic: taste, bitter and acrid.
transverse section of root shows outer most cork tissue consisting of 4-8 rows of tangentially elongated and radially arranged cells followed
by 3-6 rows of moderately thick-walled, irregular cells of secondary cortex devoid of calcium oxalate crystals and starch grains, cortex composed of large polyhedral parenchymatous cells containing abundant rounded starch grains, some cortical cells contain rosette crystals of calcium oxalate, scattered laticifer cells with brown contents, phloem consists of sieve elements and phloem parenchyama, sieve tubes thick-walled, cells more prominent towards inner region of phloem traversed by uni to tetraseriate medullary rays, phloem cells contain crystals of calcium oxalate, starch grains and laticifers similar to these found in cortex: cambium present just within the phloem consisting of 2-5 rows of thin-walled, tangentially elongated cells xylem forms the central part of root composed of vessels. 11tracheids, fibres and xylem parenchyma, vessels present throughout xylem region and arranged radially in groups of 2-7, sometime single vessels also occur, usually cylindrical having bordered pits on their walls, xylem fibres long, lignified with wide lumen, tapering on ends and have simple pits on walls, medullary rays 1-4 seriate and triseriate in outer region and uni or biseriate in inner region: cells of medullary rays radially elongated, filled with starch similar to those present in cortical cells.
Identity, purity and strength
foreign matter not more than 2 per cent
total ash not more than 4 per cent
acid-insoluble ash not more than 1 per cent
alcohol-soluble extractive not less than 2 per cent
water-soluble extractive not less than 8 per cent
constituents – glycosides (calotropin).
properties and action
rasa : katu, tikta
guna : laghu
virya : usna
vipaka : katu
karma : dipana, kaphavatahrt, bhedana, krmighna, vra¸ahara, viàaghna, kushaghna
important formulations – mahavisagarbha taila, dhanvantara ghrta
therapeutic uses – Gulma, krmiroga, kandu, kushtha, udararoga, vra¸a, svasa
dose – 1-3 g of the drug for decoction.