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.

Wednesday, 11 June 2008

Bitter Orange


Introduction
This fact sheet provides basic information about bitter orange—common names, uses, potential side effects, and resources for more information. The bitter orange tree is native to eastern Africa and tropical Asia. Today, it is grown throughout the Mediterranean region and elsewhere, including California and Florida. Bitter orange oil is used in foods, cosmetics, and aromatherapyA therapy in which the scent of essential oils from flowers, herbs, and trees is inhaled to promote health and well-being. products. Bitter orange oil from the tree's leaves is called petitgrain, and oil from the flowers is called neroli.

Common Names—bitter orange, Seville orange, sour orange, Zhi shi
Latin Names—Citrus aurantium


What It Is Used For
  • Bitter orange has been used in traditional Chinese medicineA whole medical system that originated in China. It is based on the concept that disease results from disruption in the flow of qi and imbalance in the forces of yin and yang. Practices such as herbs, meditation, massage, and acupuncture seek to aid healing by restoring the yin-yang balance and the flow of qi. and by indigenous people of the Amazon rainforest for nausea, indigestion, and constipation.
  • Current uses of bitter orange are for heartburn, loss of appetite, nasal congestion, and weight loss. It is also applied to the skin for fungal infections such as ringworm and athlete's foot.
How it is used
The dried fruit and peel (and sometimes flowers and leaves) are taken by mouth in extracts, tablets, and capsules. Bitter orange oil can be applied to the skin.

What the Science Says

  • There is not enough scientific evidence to support the use of bitter orange for health purposes.
  • Many herbal weight-loss products now use bitter orange peel in place of ephedra. However, bitter orange contains the chemical synephrine, which is similar to the main chemical in ephedra. The U.S. Food and Drug Administration banned ephedra because it raises blood pressure and is linked to heart attacks and strokes; it is unclear whether bitter orange has similar effects. There is currently little evidence that bitter orange is safer to use than ephedra.

Side Effects and Cautions

  • Because bitter orange contains chemicals that may speed up the heart rate and raise blood pressure, it may not be safe to use as a dietary supplementA product that contains vitamins, minerals, herbs or other botanicals, amino acids, enzymes, and/or other ingredients intended to supplement the diet. The U.S. Food and Drug Administration has special labeling requirements for dietary supplements and treats them as foods, not drugs.. There have been reports of fainting, heart attack, and stroke in healthy people after taking bitter orange supplements alone or combined with caffeine. People should avoid taking bitter orange if they have a heart condition or high blood pressure, or if they are taking medications (such as MAO inhibitors), caffeine, or other herbs/supplements that speed up the heart rate.
  • Due to lack of safety evidence, pregnant women should avoid products that contain bitter orange.
  • Bitter orange oil used on the skin may increase the risk of sunburn, particularly in light-skinned people.
  • 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
  • Bent S, Padula A, Neuhaus J. Safety and efficacy of citrus aurantium for weight loss. American Journal of Cardiology. 2004;94(10):1359–1361.
  • Bitter orange. Natural Medicines Comprehensive Database Web site. Accessed on May 16, 2007.
  • Bitter orange (Citrus aurantium). Natural Standard Database Web site. Accessed on May 16, 2007.
  • Orange peel, bitter. In: Blumenthal M, Goldberg A, Brinckman J, eds. Herbal Medicine: Expanded Commission E Monographs. Newton, MA: Lippincott Williams & Wilkins; 2000:287–289.
  • U.S. Food and Drug Administration. FDA Requests Seizure of More Dietary Supplements Containing Ephedrine Alkaloids. U.S. Food and Drug Administration Web site. Accessed at www.fda.gov/bbs/topics/news/2006/new01325.html on May 23, 2007.

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