The plants of family Euphorbiaceae are mostly monoecious herbs, shrubs, and trees, sometimes succulent and cactus-like. With about 300 genera and 7,500 species, Euphorbiaceae is one of the largest families of plant world, which are further characterized by the frequent occurrence of milky sap. This family occurs mainly in the tropics, with the majority of the species in the Indo-Malayan region and tropical <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />America. However, genus Euphorbia also has many species in non-tropical areas such as the Mediterranean, the Middle East, South Africa, and southern USA (Radcliffe, 1986; Chellaiah et al., 2006). A number of plants of the Spurge family are of considerable economic importance and many are grown as ornamental plants.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
In order to document the ethnobotanical uses of some medicinal plants of genus Euphorbia, survey was carried out during the year 2005, in many districts in Thar Desert. The survey was spread across the seasons to get maximum information. The information on medicinal uses of the indigenous plants have been described after gathering information from general local people, experienced aged rural folk, traditional herbal medicine practitioners and local herbal drug sellers and concluded them by consulting literature.
The randomly selected peoples of different ages from about 25 years and above were interviewed in local language. In addition, direct plant observation and identification was done with the help of local healers known as ‘gunis’. Collected plants were identified by comparing voucher specimens with identified herbarium collections in the herbarium, Department of Botany, University of Rajasthan, Jaipur, that is internationally recognized herbarium known by acronym RUBL. From the collected data, a detailed study of the plants is given here.
In India, more than about 80% of the rural people depend mainly on plants for their primary healthcare needs. Many member plants of family Euphorbiaceae are found in Rajasthan and used here in many traditional remedies. A list of plants of family Euphorbiaceae found in Rajasthan is given in Table 3.2.
Different plants of Euphorbiaceae are used in traditional medicine include: E. antiquorum, (Fig.3.3), E. antisyphilitica (Fig.3.2), E. chamaesyce, (Fig.3.4), E. cyparissias, (Fig.3.5), E. helioscopia (Fig.3.6), E. hypericifolia, (Fig.3.7), E. lathyris, (Fig.3.8), E. longifolia, (Fig.3.9), E. milii, (Fig.3.10), E. neriifolia, (Fig.3.11), E. nivulia (Fig.3.12), E. peplus, (Fig.3.13), E. resinifera, (Fig.3.14), E. royleana, (Fig.3.15).
It was also observed that most of the remedies consist of single plant part and more than one method of preparation. However, many of the remedies consist of different parts of the same plant species to treat single or more diseases.
Detailed ethanobotanical studies of Euphorbia plants found in Rajasthan, are given in Table 3.3
Detailed study of some proposed plants
Euphorbia hirta L.;
Vernacular/ common names: Dudhi, Lal-dudhi. Dugdhika, Pusitoa.
E. hirta is an annual plant growing to 0.3m by 0.25m. The flowers are monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and are pollinated by Insects. The plant prefers light (sandy) and medium (loamy) soils and requires well-drained soil. The plant prefers acid, neutral, and basic (alkaline) soils. It cannot grow in the shade, and requires dry or moist soil (Blanc et al., 1972) (Fig: 3.16, 3.17).
Sap of E. hirta contains relatively abundant white latex, which is toxic on ingestion and irritant externally, causing photosensitive skin reactions, dermatitis, and severe inflammation. The toxicity can remain high even in dried plant material (Huxley, 1992). Prolonged and regular contact with the sap is inadvisable because of its carcinogenic nature. The analysis of the latex has revealed 1-inositol, pyrrogalic and catechuic tannins and the alkaloid xanthoramnine (Matthews. 1994). Baslas and Agarwal (1980) and Gupta and Gargi (1966) found taxerol, frieldelin, P-sitosterol, myricyl alcohol, ellergic acid and hentriacontane in extracts of the stem.
Blanc et al., (1972) reported ellagic, gallic, chlorogenic and caffeic acids, kaempferol, quercitol, quercitrin (as a genin of a heteroside), and a number of amino acids. The use of latex on warts, whitlows and the like is worldwide (Hartwell, 1967). The plant has a diuretic and purgative action and is known to have a remedy for inflammation of the respiratory tract, and for asthma as it has a special reputation for causing bronchial relaxation (Johnson et al., 2004).
The plant shows antibiotic activity (Sofowora, 1993). A number of substances have been detected in the plant; tannins, gallic acid, quercetin, phenols, phyto-sterols, alcohols, alkaloids etc. (Kerharo and Adam, 1974; Burkill, 1985). The alcoholic extract of the whole plant had an anticancer action in mice (Sharma and Kumar, 2000; Hartwell, 1967). The plant has also been shown to have anthelmintic activity (Ayensu, 1979; Sofowora, 1993; Adedapo et al., 2005).
E. hirta is traditionally used to treat bronchitic asthma and laryngeal spasm, though in modern herbalism it is more used in the treatment of intestinal amoebic dysentery (Stuart.1979). It should not be used without expert guidance, however, since large doses cause gastro-intestinal irritation, nausea and vomiting (Adedapo et al., 2005). The aerial parts of the plant are harvested when in flower during the summer and can be dried for later use.
The stem, taken internally, is famed as a treatment for asthma, bronchitis and various other lung complaints (Duke and Ayensu, 1985). The herb relaxes the bronchioles but apparently depresses the heart and general respiration. The whole plant is decocted and used in the treatment of athlete's foot, dysentery, enteritis, and skin conditions (Duke and Ayensu, 1985). It has been used in the treatment of syphilis. The sap is applied to warts in order to destroy them. The treatment needs to be repeated 2 - 3 times a day over a period of several weeks to be fully effective (Chopra et al., 1986).