Aloe as laxative
As in ancient times, drug aloe (prepared from the bitter yellow juice of the leaf) and its derivatives are used extensively today as active ingredients in commercial laxative preparations, most often in combination with other botanical laxatives such as cascara sagrada bark and senna leaves or pods. Aloe leaves are cut at the base to release the juice, which is then heated to evaporate the water. The remaining dark brown mass is drug aloe. Commercial aloin is a refined form of drug aloe that contains high concentrations of barbaloin, aloe's main laxative constituent. In Germany, concentrated extracts of dried aloe leaves are used as laxatives preceding rectal surgery and as a hemorrhoid treatment.
Despite their widespread use in commercial preparations, drug aloe and aloin are considered the least desirable of plant laxatives for home health care. Besides being extremely bitter, they produce cramping and irritation in the digestive tract. Overdose or other misuse can cause abdominal pain, gastrointestinal bleeding, or even kidney disorders. Pregnant or nursing women should not take products containing drug aloe or aloin because they stimulate the uterus (which can bring on premature labor) and because they pass readily into the mother's milk, sometimes causing gastrointestinal distress in the nursing infant.
In his book Natural Health, Natural Medicine (Houghton Mifflin, 1990), Andrew Weil suggests that fresh aloe gel applied directly to the skin provides immediate relief for burns and general skin irritation or inflammation, and he cautions that commercial products which boast of their aloe content may not contain sufficient amounts to be effective.
The gel is prepared commercially by many methods, some of them patented or proprietary processes. Most involve pressing, but some entail solvent extraction; according to Albert Leung, a natural products chemist, properties of commercial gel products produced by solvent extraction vary greatly and generally are not the same as aloe gel squeezed from a fresh aloe leaf.
Aloe products are available in liquid and solid form. The most popular liquids are concentrates of various strengths; ``spray-dried'' aloe vera is the most popular solid product. Although commercial liquid concentrates are usually genuine, Leung suggests that the higher the concentration of aloe, the more degradation it has undergone. He also warns that despite claims that solid products are 200x[mult. sign] concentrates of pure aloe gel, most contain large proportions of fillers such as acacia gum, guar gum, locust bean gum, lactose, and hydrolyzed starch.
Growing aloe vera
For a fresh aloe source, your best bet is that plant on the windowsill. Happily, aloe thrives on neglect, but this tropical or subtropical native can't tolerate temperatures much below 40øF. Even a light frost will reduce it to a blackened, oozing mass of dead tissue.
My plants do well in a bright window out of direct sunlight. The soil should be well drained and porous--a coarse, sandy potting soil that's not too rich seems to suit aloe best. Overwatering and poor drainage are the greatest threats to this plant.
If you leave an aloe undisturbed in a slightly oversized pot, it will soon produce suckers which, when they're a couple of inches tall, can easily be separated from the main plant and replanted. You can also cut off an overlong stalk and simply plant it in a pot. It will root readily.