142 Handbook of herbs and spices
that Withania somnifera root has chemopreventive efficacy against forestomach and
skin carcinogenesis and warrants the identification and isolation of active compounds
responsible for its anticancer effects, which may provide the lead for the development
of antitumor agents (Padmavathi et al., 2005).
9.5 Mechanism of action of herbs and spices.....................................
The use of herbs for medical benefit has played an important role in nearly every
culture on earth. Herbal medicine was practised by ancient cultures in Asia, Africa,
Europe and the Americas. The recent popularity in use of herbals can be tied to the
belief that herbs can provide some benefit over and above allopathic medicine and
allow users to feel that they have some control in their choice of medications (Wargovich,
2001).
Ayurveda pharmacology considers drug action to be mediated totally or partially
through rasa (taste), vipaka (assimilation/fate of the drug), veerya (dosage) and prabhava
(activity) of the drug. It is worth remembering that selection of a plant reported in
classical texts for a particular disease alone is not going to help as Ayurveda is indeed
a way of life. A holistic approach is required which would re-normalize the altered
environment. Hence, in Ayurveda extracting the active principles from the crude drug
as in the case of modern medicines is not recommended since it is believed that
curative action of a crude drug is not due to one or two major constituents but
because of synergistic action of a number of major and minor constituents present in
the crude drugs. The process is different and much more complex than the simplistic
model of the modern medicines (Ayyar, 1946). One of the most promising strategies
for cancer prevention today is chemoprevention using readily available natural
substances from vegetables, fruits, herbs and spices (Das et al., 2004).
There is considerable scientific evidence, both epidemiological and experimental,
regarding vegetables and fruits as key features of diets associated with reduced risks
of diseases such as cancers and infections. This has led to the use of a number of
phytometabolites as anticarcinogenic and cardioprotective agents, promoting a dramatic
increase in their consumption as dietary supplements. It is well observed that alteration
of cell cycle regulatory gene expression is frequently found in tumor tissues or
cancer cell lines, and studies have suggested that the herbal-based or plant-originated
cell cycle regulators might represent a new set of potential targets for anticancer
drugs (Singh et al., 2003).
An impressive body of data exists in support of the concept that Indian food
ingredients can be used in preventive strategies aimed at reducing the incidence and
mortality of different types of cancers because of their antioxidative, antimutagenic
and anticarcinogenic properties. Vital ingredients used in Indian cooking include
turmeric, cloves, ginger, aniseed, mustard, saffron, cardamom and garlic (Sengupta
et al., 2004).
9.6 Evidence supporting the functional benefits of herbs and spices
Scientific evidence is accumulating that many of these herbs and spices do have