Plants in the Detection, Prevention, Cure and Management of Cancer

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Cancer is the most dreaded and prevalent disease in current times without yet a confident cure or even satisfactory management protocols in sight, in spite of the enormous amounts time, money and energy spent on cancer research in the past quarter century. This is one disease that attracted the attention of a very large number of experts in every system of medicine, physiology and genetics. An overview of various aspects of cancer can be had from the review articles in the special issue of Scientific American of September, 1996.

CRITERIA FOR AN ANTI-NEOPLASTIC DRUG

a) cytotoxic: to inhibit the cancer cell’s metabolism particularly synthesis of proteins and nucleic acids, in order to prevent cell growth, differentiation, vascularisation of the new growth, etc.;

b) mitostatic: to disrupt the process of cell division to prevent the uncontrolled number of cycles of cell division and growth, to retard the proliferation of the cancerous tissue;

c) nontoxic: the drug should be nontoxic to the rest of the body of the patient; it should not cause any side effects such as renal or hepatic dysfunction, neurotoxicity, hypersensitivity, etc.; and

d) target oriented: it should be site-selective targetting its action to the cancerous region and not cause the same effects (or at least not cause them to the same degree as on cancer) on the other parts of the patient’s body.

In addition, the drug should be effective in small and/or few doses, should not be expensive, should have longer shelf life, freely available on the market, etc.

These criteria for an anticancer drug are a tall order. Hardly there is any drug, synthetic or natural, that meets with all these qualifications and so the choice is dictated by the maximum compliance of the criteria and the philosophy of the ‘lesser evil’. With the presence of a large number of different types of cancer, each a kind of a syndrome, no single drug can be expected to be effective against more than one, at the best a few of related cancers. In the West there are very strict regulations governing drug development enforced by the respective Governments. These regulations impose heavy time and financial loads on drug development but have public safety at heart. In fact, such rigour in drug development, marketing and prescription should be implemented, more particularly, in the developing countries.

Thus, several factors made cancer drugs a multimillion dollar and multinational business, hardly within the reach of the poor, even in the western world.

In the face of a largely depressing scenario of the chemotherapeutic approach in developing safe, effective and wide range synthetic or natural drugs, alternative therapies like hormones, bone marrow transplants, immunotherapy, irradiation, etc., are in practice. It has now become evident that a miracle cure is a myth. Hence, the current focus is on prevention, early detection, and pre- and post therapy management.

ANTI-NEOPLASTIC PLANTS IN ANCIENT INDIAN MEDICAL LITERATURE 

Cancer must have been of at least of sporadic occurrence in ancient times but since it was not known in the same manner as today, we cannot expect its direct mention in classical Indian medical literature, although there are many, unverified, claims of curing cancer using classical medication, by several Ayurvedists. Certain of the symptoms described in classical literature, like internal abscesses, malignant ulcers, internal tumours, are indicative of the disease. On the basis of such an interpretation of symptoms, some species of plants mentioned, for use against these disorders, in Charaka Samhitha and Sushrutha Samhitha, can be considered antineoplastic (Table 1). Although these species are used in different other therapeutic contexts, their potential in relation to cancer is hardly recognised and none of these finds a place in modern cancer treatment.

TABLE 1

PLANTS WITH ANTINEOPLASTIC ACTIVITY FROM CHARAKA SAMHITHA

(Data gathered by Dr Mamatha Rao)

Aegle marmelos L. Rutaceae

Alangium lamarckii Thw. Alangiaceae

Asparagus racemosus Willd. Liliaceae

Barleria prionitis L. Acanthaceae

Basella rubra L. Basellaceae

Cleome viscosa L. Capparaceae

Crataeva religiosa Forst. Capparaceae

Gymnema sylvestre Roxb. Asclepiadaceae

Odina wodier Roxb. Anacardiaceae

Plumbago zeylanica L. Plumbaginaceae

Poa cyanosuroides Retz. Poaceae

Pongamia glabra Vent. Fabaceae

Pyrus communis L. Rosaceae

Sesbania grandiflora Pers. Fabaceae

Terminalia chebula Retz. Combretaceae

Sinapis glauca Roxb. Brassicaceae