PHYTOCHEMICALS AND UNDER UTILISED PLANTS OF KERALA
Plants continue to remain their historic significance as important sources of novel compounds used in biology and medicine even today. Besides micronutrients, vitamins, minerals essential to human health, naturally occurring compounds ie., phytochemicals in plants are receiving increasing attention from researchers looking into the connection between diet and disease. Phytochemicals are chemical substances produced by plants in addition to vitamins, minerals and fiber, which protect plants from the ravages of sunlight, wind and other damages caused by nature. The term �Phyto� is a Greek word which means plant. Although phytochemicals are not essential for our day to day operations, most of them appear to have disease-fighting properties. Phytochemicals are also responsible for the colour, aroma, texture taste of fruits and leaves. Within the contest of nutrition and natural health, phytochemicals only refers to plant chemicals that humans eat and use medicinally. Phytochemicals such as flavanoids, anthocyanins, carotenoids and antioxidant vitamins (C&E) have strong antioxidant potential in scavenging free radicals which contribute to aging and illness through cellular damage. They can reduce the incidence of various degenerative diseases. Many plant foods are now conferred the status of functional foods as they provide health benefits besides meeting basic nutritional needs.
In the past many centuries, science and technology have been labouring for improving the quality of life, standard of living and even life style of humanity. Unfortunately, some of these changes knowingly or unknowingly disturbed the balance of life. Thus, life style changes made their negative impacts on practices like eating patterns and dietary habits. Now refined foods, artificial flavour, colours, aroma etc. have replaced the traditional customs of eating herbs, raw foods, unrefined foods etc., which used to provide phytochemicals at no extra cost. However, the scientific community has now accepted the beneficial side of these chemicals and its ability to prevent and control various diseases.
Herbal remedies and food preparations are rapidly gaining popularity throughout the world as a result of dissatisfaction with modern medicine/food preparations, believing that all these preparations are having negative side effects. It is a widely held belief that herbal preparations are "natural" and are therefore intrinsically harmless. However, their effects can be very powerful and potentially lethal if used incorrectly.
India has an ancient cultural heritage, which was influenced by the insight of Arsha Bharatha (Indian) Saints who led a spiritual life in close association with the Mother Nature. This association can be seen in every aspect of our life including dietary habits, religious practices and festivals, where plants and plant products play a major role. A great majority of Indians are vegetarians. This again proves the importance of plants with respect to our nutrition. Practice of Ayurveda involves the application of herbal medications and nutritional supplements. Thus, Indians are blessed with the potentialities of plant foods. Our illustrious ancestors have better documented the promotive, preventive and curative properties of several herbs in the classic Ayurvedic texts. They also recommended the inclusion of some of these herbs in the dietary management. Our indigenous food items, beverages and culinary preparations are knowingly or unknowingly exploiting the goodness of plant foods. India is perhaps the only country in the world where vegetarianism exists among communities and societies for hundreds of generations. The overall figure of vegetarianism in the whole country in 1971 was 28%.
Consumption of green leafy vegetables for health benefits is a common practice in Kerala. Different items are regularly consumed in this category. The major and acceptable green leafy vegetable of Kerala is the leaves of Moringa pterygosperma Gaertn (Moringaceae), commonly known as drum sticks are generally recommended in diseases of liver, spleen etc. They are rich in minerals, vitamins, tannins, phenolic compounds, mucilage etc. they are also mentioned for the treatment of ascitis rheumatism and anaemia in folk medicine. Likewise, thazhuthama, (Boerhavia diffusa Linn of the family Nictaginaceae family) is an under utilised leafy vegetable. But it is popular for its medicinal properties and it is considered as the source of plant of the drug punarnava. Punarnavas has been suggested as a Rasayana in Ashtangahridaya according to which it could rejuvenate even the most unhealthy or old and give them new life.
Now a days the cyanophycean algae, spirullina is very popular for its capabilities. It is known as a "superfood" due to high content of nutrients compared to other plant sources of food, because its nutrients are more concentrated than other foods, plants, grains or herbs. It contains all the essential amino acids, a high level of beta-carotene (provitamin A), B vitamins, trace minerals, fatty acids, chlorophyll and other important micronutrients. Recent studies reveal therapeutic significance of spirulina as hypocholesterolemic, immunostimulant, antiviral and antimutagenic properties. A detailed study with under-utilised leaves of the tropical region, Kerala would reveal the potentialities of these plants. Systematic blending of commonly available herbs would produce cheap, effective, and phytochemicaly rich food supplement and valuable phytochemicals for commercialisation in place of costly food supplements.
There are thousands of tropical fruits available in Kerala. Unfortunately most of the native fruits are under-utilised due to lack of proper collection, systematic processing and negligence from the part of scientists and traders. One of the popular tropical fruits of Kerala is Jackfruit (Artocarpus integrifolia). Jackfruit is enriched with the proteins, lectins. Lectins are heterogenous group of proteins or glycoproteins sharing a common ability to recognize and combine with specific carbohydrate moieties on cell surfaces. Lectins are sugar-binding proteins or glycoproteins of non-immune origin derived from various plants or animals with specific sugar binding capacity. The main characteristics of lectins are their ability to bind sugars, to agglutinate cells and to stimulate lymphocytes with varying degrees of specificity. Lectins are of great interest to immunologists because of their ability to interact with lymphocytes and to induce blast cell formation. Two types of lectins, one (Jackfruit lectin JFL) from Artocarpus integrifolia seeds (Plavu : chakka) and another (Artocarpus hirsuta Agglutinin, AHA) from Artocarpus hirsute (Wild jack fruit : anjili chakka) available in Kerala. Gaikwad et al (2002) recently reported about the unfolding, inactivation and dissociation of the lectin from Artocapus hirsuta after chemical and thermal denaturation. Unfortunately anjili fruits are one of the under utilised fruits of Kerala. It is a common fruit during summer months. After using its flakes, the discarded seeds are dried and are used directy. Now a days there are studies going on the lectins present in these seeds as mentioned earlier. There are also practice of collecting edible oil from its seeds. Hence systematic a study has to be conducted the phytochemical potentialities of flakes, seeds and oil from it.