ARKA (Leaf)
Arka consists of dried leaves of Calotropis procera (Ait.) R.Br. (Fam. Asclepiadaceae), found wild more or less throughout India.
SYNONYMS
Sanskrit : Bhanu, Ravi, Tapana
Assamese : Akan, Akand
Bengali : Akanda, Akone
English : Madar Tree
Gujrati : Aakado
Hindi : Aak, Akavana, Madar
Kannada : Ekka, Ekkadagida, Ekkegida
Kashmiri : Acka
Malayalam : Erikku
Marathi : Rui
Oriya : Arakha
Punjabi : Ak
Tamil : Erukku, Vellerukku
Telugu : Jilledu
Urdu : Aak, Madar
DESCRIPTION
a) Macroscopic
Sub-sessile, 6-15 cm by 4.5-8 cm, broadly ovate, ovate-oblong, elliptic or obovate acute, pubescent when young and glabrous on both sides on maturity.
b) Microscopic
Midrib-transverse section through midrib shows an upper and lower single layered epidermis externally covered with thick, striated cuticle, few epidermal cells on both surfaces of leaf elongated to form un i-seriate, 2-3 celled trichomes, epidermal cells cubical and radially elongated, epidermis followed by 3-8 layered collenchyma on both lower and upper surfaces, parenchymatous cells thin-walled, isodiametric to circular with intercellular spaces present in ground tissue, stele crescent shaped composed of bicollateral and open vascular bundle, xylem consists mostly of vessels and tracheids, a strip of cambium present between xylem and phloem tissues, laticifers also present in the phloem and parenchymatous zone. Lamina-dorsiventral with mesophyll differentiated into a palisade and spongy tissue, upper and lower epidermis covered externally with a thick, striated cuticle, below upper epidermis three rows of elongated, closely arranged palisade parenchyma present, spongy parenchyma tissues almost radially elongated with intercellular spaces, central cells irregular in shape, laticifers and vascular bundles also present scattered in this region
IDENTITY, PURITY AND STRENGTH
Foreign matter Not more than 2 per cent, Appendix 2.2.2.
Total Ash Not more than 21 per cent, Appendix 2.2.3.
Acid-insoluble ash Not more than 5 per cent, Appendix 2.2.4.
Alcohol-soluble extractive Not less than 5 per cent, Appendix 2.2.6.
Water-soluble extractive Not less than 24 per cent, Appendix 2.2.7.
CONSTITUENTS – Glycoside (Calotropin).
PROPERTIES AND ACTION
Rasa : Katu, Tikta
Guna : Laghu, Sara, Snigdha
Virya : Usna
Vipaka : Katu
Karma : Bhedana, Dipana, Krmighna, Visaghna, Vranahara, Vatahrt, Sopha, Svasahara
IMPORTANT FORMULATIONS – Arkalavana
THERAPEUTIC USES – Svasa, Gulma, Krmiroga, Kandu, Kustha, Vrana, Sotha, Slesmodara Roga, Pliharoga, Arsa
DOSE – 250-750 mg of the drug in powder form.