Hin:Asok, Asoka; Ben:Ashok; Mal:Asokam;
Tel: Asokamu, Vanjalamu
Importance: Ashoka, the sacred tree of Hindus and Buddhists, possesses varied medicinal uses. The bark is useful in dyspepsia, fever, dipsia, burning sensation, visceromegaly, colic, ulcers, menorrhagia, metropathy, leucorrhoea and pimples. The leaf juice mixed with cumin seeds is used for treating stomachalagia. The floweres are considered to be uterine tonic and are used in vitiated conditions of pitta, syphilis, cervical adinitis, hyperdipsia, burning sensation, haemorrhoids, dysentery, scabies in children and inflammation. The well-known Ayurvedic preparations are ”Ashokarishta” and “Ashokaghrita”. Ashokarishta is prescribed in leucorrhoea, haematuria, menorrhagia and other diseases of genitourinary system of females.
Distribution: Ashoka is found almost throughout India, except North-Western India, upto 750m. It is also found in the Andaman Islands.
Botany: Saraca asoca (Roxb.) de Wilde. syn. S. indica auct. non Linn. is a medium sized evergreen tree growing upto 9m height with numerous spreading and drooping glabrous branches. Leaves are pinnate, 30-60cm long having 2-3 pairs of lanceolate leaflets. Flowers are orange or orange yellow, arranged in dense corymbs and very fragrant. Fruits are flat black pods, leathery and compressed with 4-8 seeds/pod. Seeds are ellipsoid oblong and compressed. The bark is dark brown to grey or black with a warty surface. The thickness varies from 5mm to 10mm. The entire cut surface turns reddish on exposure to air. Polyalthia longifolia (Annonaceae) is equated with the name Asoka by some (Kapoor & Mitra, 1979; Chunekar, 1982) and is often used as an adulterant of the genuine Asoka bark or as a substitute (Warrier et al,1996).
Agrotechnology: Asoka grows well in areas with well distributed rainfall and in slightly shady areas. Asoka requires soil rich in organic mater and moisture. The best season of planting is June-July. It is also grown in summer, if irrigation facilities are available. The plant is seed propagated. Seeds are formed usually during February-April. Seeds are collected when they are ripen and fall down and are sown after soaking in water for 12 hours on the prepared beds. Seeds germinate within 20 days. The seeds are then planted in polybags. 2-month-old seedlings from the polybags are used for transplanting. Square shaped pits of 60cm depth are taken at 3m spacing and filled with topsoil, sand and dried cowdung. On this the seedlings are planted. Application of FYM at 10kg/tree/year is highly beneficial. Chemical fertilisers are not usually applied. Irrigation during summer months is essential. No serious pests or diseases are generally noted in this crop. If properly cultivated, Asoka can be cut after 20 years and the bark collected. It is cut at a height of 15cm from the soil level. If given irrigation and fertilisers, the cut wood will sprout again and harvested again after 5 years. This can be continued. When it is difficult to cut the tree, the bark can be peeled off from one side first. When the bark grows and cover that part, the other side can be peeled off. This is also continued (Prasad et al, 1997; Karshakasree, 1998).
Properties and activity: Flowers give -sitosterol, flavonoids and flavone glycosides-quercetin, kaempferol-3-O- -D- glucoside, quercetin-3-O- -D-glucoside. The anthocyanins present are pelargonidin-3, 5-diglucoside and cyanadin-3, 5-diglucoside. Bark yields catechol and sterols-(24)-24-methyl cholest-5-en-3 -ol, (22E, 24)-24-ethylcholesta-5, 22-dien-3 -ol and (24)-24-ethyl cholest-5-en-3 -ol, a wax containing n-alkanes, esters and free primary alcohols. Alcoholic extract and glycoside P2 from stem bark is oxytoxic. Aerial part is CNS active, hypothermic, CNS depressant and diuretic. Stem bark is anticancerous, has spasmodic action on rabbit intestine and cardiotonic action in frog and dog. Seed is antifungal. Stem bark is astringent, antileucorrhoeic, antibilious and uterine sedative. Flower is uterine tonic, antidiabetic and antisyphilitic. Stem bark and flower is antibilious (Husain et al, 1992).