henna chemistry
Posted by atul mulay on March 18, 2000 at 05:30:45:
jaxofhearts gave this response on 3/14/2000:
Okay here we go... I did a bit of research and found a fact sheet on the actual plant at about.com. I can't get in depth to the exact chemical on the skin that reacts with the chemical in the paste but it does list active chemicals. So sorry this was slow in coming but I wanted to answer as thoroughly as possible I hope this helps. For future information you may want to check the references that the fact sheet lists.
This is directly copied from about.com...
Source: Simon, J.E., A.F. Chadwick and L.E. Craker. 1984. Herbs: An Indexed Bibliography. 1971-1980. The Scientific Literature on Selected Herbs, and Aromatic and Medicinal Plants of the Temperate Zone. Archon Books, 770 pp., Hamden, CT.
Henna, Lawsonia inermis L., a perennial shrub native to northern Africa, Asia, and Australia, is naturalized and cultivated in the tropics of America, Egypt, India, and parts of the Middle East. Also known as El-Henna, Egyptian priest, and mignonette tree, the species is sometimes classified as Lawsonia alba Lam. or Lawsonia ruba. Reaching a height of up to 6 meters, the plant has fragrant white or rose-red flowers.
The reported life zone of henna is 19 to 27 degrees centigrade with an annual precipitation of 0.2 to 4.2 meters and a soil pH of 4.3 to 8.0 (4.1-31). Henna is planted today primarily as an ornamental hedge, but is probably best known for the dried, ground leaves (called henna) traditionally used to produce colorfast orange, red, and brown dyes. Dried, powdered leaves of henna contain about 0.5 to 1.5 percent lawsone, the chief constituent responsible for the dyeing properties of the plant (1.1-273, 14.1-35). Henna also contains mannite, tannic acid, mucilage, gallic acid, and napthaquinone (7.6-192).
The leaves of henna have been used in Asia since antiquity as a hair, nail, and skin dye. In the West and the Middle East, henna is used in hair shampoos, dyes, conditioners, and rinses. Henna dye products are mixed with indigo or other plant material to obtain a greater color range. Extracts of henna are also used to stain wood and to dye fabrics and textiles.
As a medicinal plant, henna has been used for astringent, antihemorrhagic, intestinal antineoplastic, cardio-inhibitory, hypotensive, and sedative effects (7.6-192, 11.1-154). It has also been used as a folk remedy against amoebiasis, headache, jaundice, and leprosy (11.1-154). Henna extracts show antibacterial, antifungal, and ultraviolet light screening activity (1.8-169, 7.2-21,14.1-21, 14.1-35). Henna has exhibited antifertility activity in animals and may induce menstruation (7.5-76, 11.1-154).
The dried leaf and petiole of henna are generally recognized as safe when used as a color additive for hair (21 CFR section 73.2190 [1982]).
[Note: References listed above in parentheses can be found in full in the original reference].
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