Calotropis procera (Asclepiadaceae) is a wild shrub, which grows up to a height of 1-3 m and its leaves are 10–13 cm wide by 17–19 cm long. Calotropis procera (Ait.) R.Br. commonly known, as ‘Akra’ is a popular medicinal plant found throughout the tropics of Asia and Africa and is used in many traditional systems of medicine. Important factors of the various parts of this plant have been widely reported. Calotropis procera latex has been used in leprosy, eczema, inflammation, cutaneous infections, syphilis, malarial and low hectic fevers, and as abortifacient ( Kumar and Basu, 1994). Leaves: in rheumatism, as an anti-inflammatory and antimicrobial and Roots: as hepatoprotective agents, against colds and coughs, syphilis and elephantiasis, as an anti-inflammatory, analgesic, antimalarial and antimicrobial. Flowers: as cytostatic, abortifacient, antimalarial, in asthma and piles and villagers in Bikaner district ingest almost all plant parts in various dietary combinations for malarial fevers and pyrexias (Sharma and Sharma, 2000). The plant produces latex in the laticifers. It has been established that laticifer differentiation in vitro is a cytokinin-dependent process and among the cytokinins, FAP was more effective than BA and 2-iP. But the type of auxin and its concentration also play an important role in modifying the effect of cytokinin. Among the different auxins used IAA was more effective for laticifer differentiation than IBA and NAA, while 2,4D was inhibitory. Maximum laticifer differentiation (17•01% was observed on MS medium supplemented with 4•6 M FAP and 1 M IAA (Suri and Ramawat, 1995). Dried latex and chloroform extract of roots has been reported to possess anti-inflammatory activity (Kumar and Basu,1994). Aqueous extract of the flowers has been found to exhibit analgesic, antipyretic and anti-inflammatory activity. The alcoholic extract from different parts has been found to possess antimicrobial and spermicidal activity (Kamatha et al., 2002) The anti-inflammatory property of the latex of Calotropis procera was studied on carrageenin- and formalin-induced rat paw oedema model. A single dose of the aqueous suspension of the dried latex was effective to a significant level against the acute inflammatory response (Basu and Nag Chaudhuri 1991, Kumar and Basu, 1994). A literature survey of Calotropis procera revealed that the plant contains mainly cardenolides besides steroids and triterpenes. From the hexane-insoluble fraction of this plant a new free cardenolide named proceragenin has been isolated. The medicinal importance of Calotropis procera prompted the studies on pharma-cological screening of the antibacterial and anti-aggregating activities of proceragenin (Akhtar, 1992). Procesterol, a new steroidal hydroxy ketone, has been isolated from the fresh and undried flowers of Calotropis procera. The chemical and spectral studies identified it as a C-6 C-24 diepimer of stigmast-4-en-6 -ol-3-one (Khan et al.,1989). Bast fibres of Calotropis procera (aak) plant have been separated by retting. The yarn of blend of cotton and aak in 1:1 proportion was inferior to cotton in respect of strength, fineness and evenness. The properties of cloth indicated that aak cloth has high tensile and abrasion strength and more weight per square metre than cotton cloth. The study suggested that good quality cloth could be prepared from aak yarn if its evenness and fineness are improved (Varshney and Bhoi 1987, 1988). Mosquito control by Calotropis latex has been reported by Girdhar et al., (1984). The effect of crude fractions of C procera, its flower, bud and root were tested against a chloroquine sensitive strain, MRC 20 and a chloroquine resistant strain, MRC 76 of Plasmodium falciparum (Sharma and Sharma, 1999). The dry latex (DL) of Calotropis procera (Asclepiadaceae), a potent anti-inflammatory agent has been evaluated for anti-diarrhoeal activity. Anti-diarrhoeal effects of C. gigantea used traditionally in Indian system of medicine were recorded. The remarkable anti-diarrhoeal effect of C.gigantea extract against castor oil-induced diarrhoea model attests to its utility in a wide range of diarrhoeal states (Chitme et al., 2004). Like atropine and phenylbutazone (PBZ), a single oral dose of DL (500 mg/kg) produced a significant decrease in frequency of defecation, severity of diarrhoea and afforded protection from diarrhoea in 80% rats treated with castor oil ( Kumar et al., 2001) . Besides this, the plant contains several useful enzymes. A protease was purified to homogeneity from the latex of medicinal plant Calotropis procera The molecular mass and isoelectric point of the enzyme are 28.8 kDa and 9.32, respectively. Hydrolysis of azoalbumin by the enzyme was optimal in the range of pH 7.0–9.0 and temperature 55–60 °C. The enzyme hydrolyses denatured natural substrates like casein, azoalbumin, and azocasein with high specific activity. Proteolytic and amidolytic activities of the enzyme were activated by thiol protease activators and inhibited by thiol protease inhibitors, indicating the enzyme to be a cysteine protease ( Dubey and Jagannadham 2003). The role of antioxidants, which are thought to scavenge the oxygen-free radicals in plants exposed to relatively low concentrations of ambient air pollutants for long durations, was studied for a year. Increases were observed in superoxide dismutase peroxidase activity, sulphate and leaf area to dry weight ratio, and decreases in stomatal conductance, ascorbic acid, protein content and total lipids, as a general response of all the plants in the polluted area. The results indicate that high peroxidase activity in the control plants and enhanced superoxide-dismutase activity in the polluted area might have enhanced the ability of Cassia siamea to tolerate stress better than Dalbergia sissoo. Similarly, enhanced activities in the polluted sites made Calotropis procera more tolerant of stress than Ipomoea fistulosa. Thus, it appears that monitoring of antioxidant activities offers a useful tool in understanding the mechanisms which make plants relatively tolerant in field conditions (Rao and Dubey 1990). Thus the Calotropis procera plants are more tolerant to field stress conditions. Pretreatment with an ethanolic latex extract of Calotropis procera at a dose of 300 mg/kg body wt., administered orally thrice a day for 30 days, reduced significantly (p < 0.01) the elevated marker enzyme levels in serum and heart homogenates in isoproterenol-induced myocardial infarction. Histopathological observation revealed a marked protection by the extract in myocardial necrotic damage (Mueen et al., 2004).