Antitumour drugs are used in the treatment of cancer. The cancer or carcinogenic growth is an abnormal mass of new tissue growing in or on part of the body. Several types of carcinogenic growths have been reported. The cancer is regarded to be an incurable disease in secondary stages. The radioactive substances, metal compounds and several chemotherapeutic drugs have been suggested to control carcinogenic growths. Vinca is good choice for treatment of cancer.
SYNONYMS:- Catharanthus, Vinca Rosea, Periwinkle.
BIOLOGICAL SOURCE:- It is the dried whole plant of Catharanthus roseus G. Don., belonging to family Apocynaceae.
Cultivation & Collection:- This is a drought-resistant species and can be propagated by seeds and cuttings. As the plant blooms throughout the year, the collections of seeds is not difficult. The plant requires very little irrigation and can hence be raised as off-season crop. The cultivation is done in June-July in India and first crop of leaves is ready in November. Harvesting is done 2 to 3 times a year. The seeds are collected and plant is uprooted in February. Depending upon the type of soil and amount of irrigation, about 700 to 1000 kg of leaves per hectare are collected. Leaves are thoroughly dried and sent to the market. Roots are washed, dried and marketed.
Organoleptic Characters: The leaves are green, roots are pale grey, flowers are violet, pink-white or carmine-red in colour. The odour is characteristic and taste is bitter. Vinca is an erect, pubescent herb, with branched tap-root. Leaves are simple, petiolate, ovate, or oblong, unicostate, reticulate. entire, brittle with acute apex and glossy appearance. Flowers are bractate, pedicellate, complete, hermaphrodite, normally 2 to 3 in cymose axillary clusters. Fruits are follicles with several black seeds.
Microscopic Character: Upper surface shows presence of single layer of rectangular celled epidermis with unicellular covering trichomes. Palisade is made up of single layer beneath upper epidermis and contains compact elongated cells Spongy parenchyma is 5 to 8 layered with intercellular spaces.Midrib shows presence of collenchyma below the upper epidermis and above the lower epidermis. Xylem and phloem are present in the centre. Cruciferous stomata are present more frequently on lower epidermis. Calcium oxalate crystals are absent.
T.S. of vinca
Chemical Constituents:
Vinca contains wide varieties of chemicals including the glycosides and alkaloids. The indole-indoline alkaloids are very important constituents About 60 alkaloids have been isolated so far from different parts of vinca. The important alkaloids with anticancer property are vincristine and vinblastine. Vincristine is obtained in about 0.0002 % yield from the crude drug. The other alkaloids present in the drug are ajmalicine, serpentine, lochnerine and tetrahydroalstonine. The total alkaloidal content of the drug is about 1%, of which only a fraction contains therapeutically active alkaloids.
Both vinblastine and vincristine have the same structures with the difference that in vinblastine there is N-methyl group while, in vincristine it is N-formyl group and both possess different activities. The other alkaloids are vindoline, vindolinine and catharanthine
USES:
Vincristine is used in treatment of leukaemia. Vinblastine is used for the treatment of generalised Hodgkin’s disease and chorionepithelioma. Periwinkle has been studied for potential antimicrobial and antiprotozoal applications, as well as for use in diabetes and wound healing; however, there is not enough reliable information to recommend the plant for these uses. Vinca also exhibits hypotensive and antidiabetic activity.
Side Effects:- Periwinkle is UNSAFE. It can cause side effects such as nausea, vomiting, and other stomach and intestinal symptoms. It can also cause nerve, kidney, and liver damage. Large amounts can cause very low blood pressure.
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