Importance of the plants basically originates due to the presence of specific biological active classes of organic compounds. Plants are rich in a wide variety of secondary metabolite such as tannins, terpenoids, alkaloids and flavonoids etc, which have been found to exhibit antimicrobial properties. The affordability, reliability, availability and low toxicity of medicinal plants in therapeutic use has made them popular and acceptable by mankind for implementation in medical health care all over the world.
It is true that without nature humans life is not possible. The food, clothes and shelter are three basic necessity of human beings and an important one necessity is good health, which provided by plant kingdom. Plant kingdoms are the rich source of organic compounds, many of which have been used for medicinal purposes. In traditional medicine, there are many natural crude drugs that have the potential to treat many disease and disorders one of them is Ricinus communis ( CASTOR).
Morphology and Habitat
The castor oil plant is a fast-growing, suckering perennial shrub or occasionally a soft wooded small tree up to 6 meter or more, but it is not hardy in nature. This plants was cultivated for leaf and flower colors and for oil production. Leaves are green or reddish in colour and about 30-60 cm in diameter. The leaves contain 5-12 deep lobes with coarsely toothed segments which are alternate and palmate. The stems are varying in pigmentation. The flowers are monoecious and about 30-60 cm Long. The fruit is a three-celled thorny capsule. The capsule of fruit covered with soft spins like processes and dehiscing into three 2-valved cocci. The seeds are considerable differences in size and colour. They are oval, somewhat compressed, 8-18 mm long and 4-12 mm broad. The testa is very smooth, thin and brittle. Castor seeds have a warty appendage called the caruncle, which present usually at one end from which runs the raphe to terminate in a slightly raised chalaza at the opposite end of the seed.
This plant is common and quite wild in the jungles in India and it is cultivated throughout India, chiefly in the Madras, Bengal and Bombay presidencies.
Two varieties of this plant are known
- A perennial bushy plant with large fruits and large red seeds which yields about 40 P.C of oil,
- A much smaller annual shrub with small grey (white) seeds having brown spots and yielding 37% of oil1.
Benefits of Castor
Castor antioxidant activity can be concluded by using lipid method and free radical scavenging effect on 2,2 picrylhydrazyl radical (DPPH) and hydroxyl hydrogen peroxide. The high antioxidant activity of the seed of communism at low concentration shows that it could be very useful for the treatment of disease resulting from oxidative stress. The responsible chemical constituent of antioxidant activity are Methyl ricinoleate, Ricinoleic acid, 12 octadecadienoic acid and methyl ester stem and leave extracts also produce antioxidant activity due to the presence of flavonoids in their extracts.
The ethanolic root extract of castor is effective in treatment of asthma because of its antiallergic and mast cell stabilizing potential effect. Saponins has mast cell stabilizing effect and the flavonoids possess smooth muscle relaxant and bronchodilator activity; the apigenin and luteolin like flavonoids were generally inhibit basophil histamine release and neutrophils beta glucuronidase release, and finally shows in-vivo antiallergic activity. The Castors ethanolic extract decreases milk induced leucocytosis and eosinophilia and possess antiasthmatic activity due to presence of flavonoids or saponins.
The methanol extracts of Castor seed possess positive preliminarily Phytochemical tests for both steroids and alkaloids. The sex hormone being steroidal compound’s (phytosterols) and the presence of steroids in methanol extract of Castor seed produces anti-fertility effect.
Hepato protective activity:
Castor leaves ethanolic extract 250/500mg/kg body weight possesses hepatoprotective activity due to their inhibitory activities of an increase in the activities of serum transaminases and the level of liver lipid per oxidation, protein, glycogen and the activities of acid and alkaline phosphatase in liver induced by carbon tetrachloride (CCL4).
The presence of flavonoids in ethanol extract of castor produces beneficial effect the flavonoids have the membrane stabilizing and antiperoxidative effects. Hence the castor increase the regenerative and reparative capacity of the liver due to the presence of flavonoids and tannins. The anticholestatic and hepatoprotective activity is seen against paracetamol-induced hepatic damage due to the presence of N-demethyl ricinine isolated from the leaves of castor Linn. The whole leaves of castor shows the protective effect against liver necrosis as well as fatty changes induced by CCL4 while the glycoside and cold aqueous extract provide protection only against liver necrosis and fatty changes the stages of acute inflammation.
The antimicrobial activities of castor were good against dermatophytic and pathogenic bacterial strains Streptococcus progenies, Staphylococcus aureus as well as Klebsiella pneumonia, Escherichia coli. The different solvent extracts of roots of castor (200mg/ml) possess antimicrobial activity which can be assesed by using well diffusion method against pathogenic microorganisms such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium, Proteus vulgaris, Bacillus subtilis, Candida albicans and Aspergillus niger. The hexane and methanol extracts showed maximum antimicrobial activity where the aqueous extracts has no significant antimicrobial properties.
Wound healing activity
The castor possess wound healing activity due to the active constituent of castor oil which produce antioxidant activity and inhibit lipid per oxidation. Those agents whose inhibits lipid per oxidation is believed to increase the viability of collagen fibrils by increasing the strength of collagen fibres, increasing the circulation, preventing the cell damage and by promoting the DNA synthesis.
The 250 and 500 mg/kg dose of castor methanolic leaves extract possess protective effect in prevention of cellular events during edema formation and in all the stages of acute inflammation. The anti-inflammatory activity of castor methanolic extract was due to the presence of flavonoids because the flavonoids.
The castor oil of Castor seed possess significant antiulcer propertie at a dose of 500 mg/kg and 1000 mg/kg, but at the dose 1000 mg/kg was more potent against the ulceration caused by pylorus ligation, aspirin and ethanol in rats. The result showed that the antiulcer activity of Castor is due to the cytoprotective action of the drug or strengthening of gastric mucosa and thus enhancing the mucosal defence.