Herbalism is a traditional medicinal or folk medicine practice based on the use of plants and plant extracts. Herbalism is also known as botanical medicine, medical herbalism, herbal medicine, herbology, and phytotherapy. Sometimes the scope of herbal medicine is extended to include fungi and bee products, as well as minerals, shells and certain animal parts.

Many plants synthesize substances that are useful to the maintenance of health in humans and other animals. These include aromatic substances, most of which are phenols or their oxygen-substituted derivatives such as tannins. Many are secondary metabolites, of which at least 12,000 have been isolated — a number estimated to be less than 10% of the total. In many cases, these substances (particularly the alkaloids) serve as plant defense mechanisms against predation by microorganisms, insects, and herbivores. Many of the herbs and spices used by humans to season food yield useful medicinal compounds.

All plants produce chemical compounds as part of their normal metabolic activities. These include primary metabolites, such as sugars and fats, found in all plants, and secondary metabolites found in a smaller range of plants, some useful ones found only in a particular genus or species. Pigments harvest light, protect the organism from radiation and display colors to attract pollinators. Many common weeds have medicinal properties.

The functions of secondary metabolites are varied. For example, some secondary metabolites are toxins used to deter predation, and others are pheromones used to attract insects for pollination. Phytoalexins protect against bacterial and fungal attacks. Allelochemicals inhibit rival plants that are competing for soil and light.

Plants upregulate and downregulate their biochemical paths in response to the local mix of herbivores, pollinators and microorganisms.The chemical profile of a single plant may vary over time as it reacts to changing conditions. It is the secondary metabolites and pigments that can have therapeutic actions in humans and which can be refined to produce drugs.

Plants synthesize a bewildering variety of phytochemicals but most are derivatives of a few biochemical motifs.

Thursday, 22 May 2008

ASIAN GINSENG



Introduction
This fact sheet provides basic information about the herbA plant or part of a plant used for its flavor, scent, or potential therapeutic properties. Includes flowers, leaves, bark, fruit, seeds, stems, and roots. Asian ginseng—common names, uses, potential side effects, and resources for more information. Asian ginseng is native to China and Korea and has been used in various systems of medicine for many centuries. Asian ginseng is one of several types of true ginseng (another is American ginseng, Panax quinquefolius). An herb called Siberian ginseng or eleuthero (Eleutherococcus senticosus) is not a true ginseng.

Common Names—Asian ginseng, ginseng, Chinese ginseng, Korean ginseng, Asiatic ginseng
Latin Name—Panax ginseng


What It Is Used For
Treatment claims for Asian ginseng are numerous and include the use of the herb to support overall health and boost the immune system. Traditional and modern uses of ginseng include:
Improving the health of people recovering from illness
  • Increasing a sense of well-being and stamina, and improving both mental and physical performance
  • Treating erectile dysfunction, hepatitis C, and symptoms related to menopause
  • Lowering blood glucose and controlling blood pressure

How It Is Used
The root of Asian ginseng contains active chemical components called ginsenosides (or panaxosides) that are thought to be responsible for the herb's medicinal properties. The root is dried and used to make tablets or capsules, extracts, and teas, as well as creams or other preparations for external use.

What the Science Says
Some studies have shown that Asian ginseng may lower blood glucose. Other studies indicate possible beneficial effects on immune function.
To date, research results on Asian ginseng are not conclusive enough to prove health claims associated with the herb. Only a handful of large clinical trials on Asian ginseng have been conducted. Most studies have been small or have had flaws in design and reporting. Some claims for health benefits have been based only on studies conducted in animals.
NCCAM supports studies to better understand the use of Asian ginseng. Areas of recent NCCAM-funded research include Asian ginseng's interactions with other herbs and drugs and the herb's potential to treat chronic lung infection, impaired glucose tolerance, and Alzheimer's disease.

Side Effects and Cautions
When taken by mouth, ginseng is usually well tolerated. Some sources suggest that its use be limited to 3 months because of concerns about the development of side effects.
The most common side effects are headaches and sleep and gastrointestinal problems.
Asian ginseng can cause allergic reactions.
There have been reports of breast tenderness, menstrual irregularities, and high blood pressure associated with Asian ginseng products, but these products' components were not analyzed, so effects may have been due to another herb or drug in the product.
Asian ginseng may lower levels of blood sugar; this effect may be seen more in people with diabetes. Therefore, people with diabetes should use extra caution with Asian ginseng, especially if they are using medicines to lower blood sugar or taking other herbs, such as bitter melon and fenugreek, that are also thought to lower blood sugar.
Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.


Sources
Ginseng, Asian (Panax ginseng). In: Coates P, Blackman M, Cragg G, et al., eds. Encyclopedia of Dietary Supplements. New York, NY: Marcel Dekker; 2005:265-277.

Ginseng, Panax. Natural Medicines Comprehensive Database Web site. Accessed on July 2, 2007.

Ginseng. Natural Standard Database Web site. Accessed on June 28, 2007.

Ginseng root. In: Blumenthal M, Goldberg A, Brinckman J, eds. Herbal Medicine: Expanded Commission E Monographs. Newton, MA: Lippincott Williams & Wilkins; 2000:170-177.

National Center for Complementary and Alternative Medicine. Hepatitis C and Complementary and Alternative Medicine: 2003 Update. National Center for Complementary and Alternative Medicine Web site. Accessed on July 9, 2007.

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