Tuesday, May 31, 2011

Economic value of Medicinal Plants

Biodiversity has an economic value with local, regional, national and international implications. Consequently, biodiversity is often an issue of economics and so of politics. Biodiversity has also an alternative value an intrinsic value which is academic/scientific, that is unrelated to direct human use. However, the intrinsic value studies form the basis for economic valuation and exploitation.


Plant species are used for medicinal purposes in two ways:

a) as traditional medicines, singly or in formulations, such as those prepared and dispensed by traditional medical practitioners, which may or may not attract a market price; and

b) commercial products, dispensed by prescription or over the counter sales, such as patented/licensed medical products of allopathy or traditional systems of medicine.

Both these uses have economic value. For the lack of adequate and appropriate data, it is near impossible to evaluate the returns from the first category. The economic value of plant based drugs, therefore, largely rests on the second category uses. It is estimated that in the rich world, 25 per cent of all medical drugs are based on plants and their derivatives. In the poor world, this is closer to 75 per cent.

The economic value of a particular species of plants in medicinal use depends upon a number of factors, among which the following are important:

a) Certain plant species are used in a large number of formulations. The use of a particular species with reference to the number therapeutic effects it exerts or the number of formulations in which it is an ingredient, is expressed as the therapeutic index and frequency index, respectively. A higher index reflects a higher economic value attributable to a particular species. Such species are often referred to as the ‘elite species’. For example neem (Azadirachta indica) is indicated for use against 10 out of 18 symptoms in gastro-intestinal disorders and against eight out of 11 symptoms in dental care. Neem has several other medicinal and non-medicinal uses as well. Consequently, neem is one of the elite species of Indian medicinal plants.

b) Certain species are of great importance in the treatment of a particular disease as they happen to be the only (or one of very few) species with that therapeutic potential, as the alkaloids of Catharanthus roseus in the treatment of leukemia. The importance of the disease also is a factor. Such species attract high market rate.

c) Some species have a narrow distribution and/or occur in small populations. Some may be difficult to cultivate. Such species also command a higher price. For example, Trichopus zeylanica, occurring in south India, Sri Lanka and the Malay peninsula, is recently projected as the Indian equivalent of ginseng. This species now attracts a high market value.

d) Certain species of medicinal plants like Rauvolfia serpentina and Saraca asoca have been over exploited and so now occur rather scarcely in nature. It is difficult to cultivate Rauvolfia serpentina on a large scale while Saraca asoca is rather easier to propagate. The market value of some species, thus depends upon such criteria.

e) There are synthetic substitutes for several originally plant derived products, as for example clove oil. If the synthetic substitute is cheaper to produce than the plant based product and/or if the natural products have no other uses, the economic value of the natural product falls. However, certain therapeutically active constituents produced by plants like digoxin and digitoxin have not been produced synthetically. Some like vincristine, vinblastin, opiates, etc., that have been synthesised have proven to be less efficient than the natural products. The economic value of a species of medicinal plants depends upon this situation as well.

f) The economic value of a particular species varies with time. An effective synthetic substitute, or the discovery of a better natural alternative or the disuse of the species/product over a period of time, may deplete the species of its market value. For example, till sulphonamides came into use, sandalwood oil was the most widely used effective antispetic. Subsequently, sandalwood oil (Saantalum album) has fallen into disuse as an antiseptic. Its economic value should have come down but did not as sandalwood oil has other uses with higher economic returns.

g) The costs involved in isolation and purification of an active principle involve several considerations. It requires about a tonne of leaves of Catharanthus roseus to obtain one gram of the alkaloid vincristine, essentially needed to treat leukaemia. Vincristine is one of the expensive plant products costing about US$ 24,000/g. Vinblastin, another alkaloid from the same species, used to treat Hodgkin disease, is present in quantity 1,000 more times than vincristine. One gram of vinblastine costs about US$ 6,800. It is now possible to convert vinblastine into vincristine through biotransformation. There is also a growing interest in the other alkaloids present in Catharanthus roseus. Thus, several factors govern the cost of the raw material and the final product of a medicinal plant, from time to time.

The potential of plants as sources of medicine is often taken in support of identification and preservation of the world’s most species rich ecosystems. Such assessments are speculative and totally based on chance. Screening the vast vegetable world for potential sources of medicine and their use in the traditional way or through the application of biotechnology for a large scale industrial production of the active constituents or by chemical synthesis, is a very uncertain and a long term proposition that involves heavy financial investment with no certainty of the economic returns. There is no guarantee that the future drugs will all be derived from plants.

Thursday, May 12, 2011

Acoustic Benefits of Plants

Trees and shrubs have been used extensively to reduce noise from traffic on busy roads. New research shows that plants can also help to reduce background noise levels inside of buildings, particularly those in which hard, reflective surfaces dominate. If you have marble or tile flooring, plaster walls, or large glass windows or doors, you will see a significant noise reduction benefit by following the 1 plant for every 100 square foot rule. Noise reduction is beneficial to health and lowers stress levels.

The investigation of the acoustic benefits of interior plants was carried out at South Bank University in London. To quantify the acoustic effect, the sound absorption coefficients of a number of plant species were measured and compared with other building materials. Plants will have very little noise reduction effect in acoustically dead areas, such as rooms with thick carpet, heavy drapes, or paneled walls.

Results indicated that plants are generally more efficient at absorbing high sound frequencies than low frequencies. High frequencies cause the most irritation to building occupants. Noted examples of good sound absorbing plants are those listed above, particularly Spathiphyllum (peace lilly), Philodendron(sweetheart plant), Dracaena marginata (dragon tree), and Ficus benjamina (weeping fig).

An abundance of experiments and tests have been conducted to determine the effects of plants in the work environment. The results support the conclusion that workers are more creative, shoppers spend more when plants are around, and hotel occupancy rates improve with the presence of plants. The image of almost any enterprise is enhanced by plants.

Dr. Bruno Cortis, a Chicago cardiologist, says "Plants make people feel calmer and more optimistic." Interestingly, studies have shown that hospital patients who face a window with a garden view recovered more quickly than those who had to look at a wall.

Monday, April 18, 2011

Drink Tea and Fight with Cancer

Tea drinkers rejoice! Studies show that drinking tea reduces the risk of some cancers in humans. Previously tea was thought to have cardiovascular benefits, but there is mounting evidence that tea has cancer-fighting properties as well. Specifically, the antioxidant properties in green, black and oolong or real tea are cited in these studies. These teas originate from the Camellia sinensis plant and are excellent sources of polyphenols or plant chemicals (phytochemicals).

In particular real tea is rich in flavonoids, powerful antioxidants, which have been highly touted as a primary staple in the diet of the Okinawan people of Japan, otherwise known as the healthiest people on earth. Herbal teas are derived from a different plant source and lack the antioxidant properties of the flavanoids in real tea.

Antioxidants help protect the body against disease by counteracting the harmful effects of free radicals - stray, highly reactive particles that accumulate in the body as byproducts of metabolism. Free radicals injure surrounding cells through oxidation. Left unchecked they can damage cellular DNA and potentially cause cancer.

Antioxidants, such as vitamins C and E and beta-carotene are free radical scavengers. But research from both the National Foundation for Cancer Research and the University of Kansas reports that green tea is 100 times more potent than vitamin C and 25 times more potent than vitamin E at protecting cells from damage linked to cancer, heart disease and other illnesses. In addition, indications are that black tea contains the same amount of phytochemicals as green tea.

Most of the data supporting the anti-cancer benefits of tea at this point is derived from animal studies in which animals were treated with polyphenols equivalent to amounts consumed by regular tea drinkers. Evidence is the strongest for prevention of cancers of the oral cavity, stomach and colon. A few animal studies link tea with a decreased risk of lung and skin cancers . Studies in humans have been less consistent but still suggest that tea has anticancer benefits.

So drink tea to your health!

Friday, April 15, 2011

Medicinal Plants: What Makes them Different

For all intents and purposes, there is no actual difference between plants we commonly use for their curative properties, from those we don't. In that the biological process that defines plants applies to all members of the plant kingdom, any plant may serve a medicinal purpose--perhaps one we simply have yet to discover or learn to utilize.

Basically, it all comes down to the chemical make-up of a given plant as to whether it will serve a common curative function, rare curative function, or constitute that list of plants that as yet have no known curative function. But the latter list is shortening every day. For millennium, humankind used plants for their healing abilities, having no rational explanation for their effectiveness. Today, however, the fields of organic chemistry and pharmacology have qualitatively determined which chemical factors of a given plant are responsible for its therapeutic effect.

These distinctions regard the "active principles" or chemical "constituents" of a given plant.

Alkaloids rank among the most effective and therapeutic constituents of plants, as well as the most dangerous. Alkaloids are a group of naturally occurring chemical compounds which mostly contain basic nitrogen atoms. Traditionally used only as topical applications due to their ability to poison when taken internally, plants in this category include Greater Celandine, Jimsonweed, and White Hellebore.

Numbering in the thousands, alkaloids are now recognized as having remarkable therapeutic effects regarding analgesic, anti-timorous and anti-bacterial properties, but should only be utilized and administered by experienced practitioners.

Science defines glycosides as a molecule in which a sugar is bound to a small organic molecule. Glycosides play numerous important roles in living organisms.

Plants in this category include Foxglove, Alder Buckthorn, Pot Marigold, and Milk Thistle--all of which have a variety of curative properties including anti-inflammatory, antiseptic, and laxative action, and are proven to be remarkably effective against a wide variety of disease from affecting muscles tissue of the heart to easing general muscle pain; improving liver and gall bladder conditions to clearing the lungs of mucus.

Essential oils are generally aromatic, quite unstable organic compounds of a recognizable "oil-like" character. Extracted from Wild Thyme, for example, they have proven effective against respiratory infections, while the oils of Yarrow, Sweet-Flag, and Fennel are commonly used to treat infections of the digestive tract. Among the other plants commonly utilized for their curative oils are Juniper, Parsley, Rosemary, Peppermint, Dill, Anise, and Caraway.

Scientifically, Tannins are astringent, bitter plant polyphenolic compounds that either binds and precipitates or shrinks proteins and various other organic compounds including amino acids and alkaloids. They are generally utilized for their effectiveness in hastening the healing of wounds and inflamed mucous membranes. Internally, tannins extracted from herbs such as Oak Bark, Agrimony, and Garden Sage are used to treat varicose veins, hemorrhoids, and burns. Internally, they are effective against diarrhea and nausea.

Bitters varied chemical composition have been used for centuries to treat stomach disorders and digestion. There are numerous brands of bitters that were formerly marketed as patent medicines but are now considered to be digestifs, rather than medicines such as Vermouth. Centaury, Wormwood, and Blessed Thistle are among those plants used in the preparation of bitters for these therapeutic properties.

Sugars are an essential part of many medicinal preparations. Generally used as a term for a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, other sugars are used in industrial food preparation known by more specific names—glucose, fructose or fruit sugar, high fructose corn syrup. Extracted from plants such as Coltsfoot, Mallow, Ribwort, and Mullein, sugars have a wide range of healing abilities from treating diabetes to inflammation of the upper respiratory passages; providing general nourishment to treating intestinal ailments.

Vegetable fats and oils are lipid materials derived from plants. Plants store energy in their fatty oils. When isolated, they are used in ointments, a wide variety of medicines (both natural and processed), cosmetics, and are recognized primarily for their ability to effectively treat diseases of the digestive tract. Physically, oils are liquid at room temperature and fats are solid.

An organic acid is an organic compound with acidic properties. Close to sugars in biogenetic composition, organic acids are found in all plants. Among those most familiar are malic acid, citric acid, and tartaric acid. As "primary metabolites," their benefits are naturally utilized in many herbal preparations.

Wednesday, April 13, 2011

The Cornerstone of Ayurveda: Neem

Used extensively as a major component in Ayurvedic and Unani medicinal system, Neem is used for addressing a range of skin ailments. Its extracts are widely used in Ayurveda for their anti-diabetic, anti-bacterial, anti-viral, contraceptive and sedative properties.

With the sobriquet ‘Village Pharmacy’ conferred on a herb, Neem needs no introduction. Used extensively as a major component in Ayurvedic and Unani medicinal system, Neem is used for addressing a range of skin ailments. Its extracts are widely used in Ayurveda for their anti-diabetic, anti-bacterial, anti-viral, contraceptive and sedative properties. In a Neem tree, every part is believed to have medicinal properties. The leaves, bark, seeds and flowers are all used in various medicinal preparations.

Most widely used for acquiring healthy skin, the oil and extracts of the herb are widely recommended for acne treatment and skin rashes. The leaves of the tree are also reported to remove toxins, purify blood and prevent damage caused by free radical in the body by neutralizing them. Not only is it a tonic and an astringent, Neem maintains healthy blood circulation and cleanses the body of toxins and impurities. Proper usage of the herb is known to help in achieving glowing and radiant skin. When administered on skin, Neem extracts and oil remove the redness and itching while improving the condition of the skin for the duration of the treatment. In case of pimples and acne, application of Neem kills bacteria and removes inflammation, thereby making the skin smooth and supple.

Known for more than 5000 years for its wide range of therapeutic properties, the Neem tree belongs to the plant family of Meliaceae and is indigenous to the Indian sub-continent. Also found in Sri Lanka, Burma, Bangladesh and Pakistan, Neem grows in tropical and semi-tropical regions. A fast-growing ever-green tree which grows to a height of 50-56 feet, the branches of neem trees are widespread and have asymmetric leaflets.

Extracts of Neem bark are used for the overall healthy functioning of the body. Cool, bitter, astringent and acrid, its bark is efficacious in the treatment of common cold, fever and worm infestation. Widely recommended for its antiseptic property, Neem is beneficial for women and children for multiple reasons. Its antibacterial properties are especially effective for gum diseases and cavities. Due to its strong anti-oxidant properties, Neem protects against chemically induced carcinogens and liver damage by boosting antioxidant levels.

The Neem tree has been identified on the five-thousand-year-old seals excavated from the Indus Valley Civilization”. Believed to exorcise the the demon of diseases, the Ayurvedic herb is not only used for its medicinal properties, but also worshipped in India as a deity. Known to contain nimbin, nimbinene and quercentin, the leaves of the tree help in the treatment of neuromuscular pains. The leaves of this Ayurvedic plant remove toxins, purify blood and prevent damage caused by free radical in the body by neutralizing them.