Aloe

The laxatives most frequently used world-wide come from plants. Herbal laxatives are either bulk-forming or stimulating.

Stimulant laxatives are high in anthraquinone glycosides, which stimulate bowel muscle contraction. The most frequently used stimulant laxatives are senna leaves, cascara bark, and aloe latex. While senna is the most popular, cascara has a somewhat milder action. Aloe is very potent and should be used with caution. Other stimulant laxatives include buckthorn, alder buckthorn (Rhamnus frangula), and rhubarb (Rheum officinale, R. palmatum).

Aloe is a popular remedy for minor burns and a small preliminary study found it more effective than Vaseline in treating burns.¹ The stabilized aloe gel is typically applied to the affected area of skin three to five times per day. Older case studies reported that aloe gel applied topically could help heal radiation burns,² but a large, double-blind trial did not find aloe effective in this regard.³

A gel containing the Aloe vera polysaccharide acemannan was found in one double-blind trial to speed the healing of canker sores better than the conventional treatment Orabase Plain.⁴ The gel was applied four times daily. Because acemannan levels can vary widely in commercial aloe gel products, it is difficult to translate these results to the use of aloe gel for canker sores.

Aloe vera may also benefit those with genital herpes. A double-blind trial using a 0.5% Aloe vera cream found that applying the cream three times a day shortened the healing time of genital herpes outbreaks. All but 3 of 22 persons in the study who showed healing with the aloe cream had no recurrences 15 months after stopping treatment.⁵

A double-blind trial in Pakistan found that topical application of an aloe extract (0.5%) in a cream was more effective than placebo in the treatment of adults with psoriasis.⁶ The aloe cream was applied three times per day for four weeks.

A crude extract of aloe (Aloe barbadensis, Aloe vera) may help seborrheic dermatitis when applied topically. In a double-blind trial, people with seborrheic dermatitis applied either a 30% crude aloe emulsion or a similar placebo cream twice a day for four to six weeks.⁷ Significantly more people responded to topical aloe vera than to placebo: 62% of those using the aloe vera reported improvements in scaling and itching, compared to only 25% in the placebo group.

Aloe vera has been used historically to improve wound healing and contains several constituents that may be important for this effect. A group of three patients who had chronic skin ulcerations for 5, 7, and 15 years, respectively, had a rapid reduction in ulcer size after the application of aloe gel on gauze bandages to the ulcers, according to a preliminary report.⁸ A controlled study found most patients with pressure ulcers had complete healing after applying an aloe hydrogel dressing to the ulcers every day for ten weeks.⁹ However, this result was not significantly better than that achieved with a moist saline gauze dressing. The amorphous hydrogel dressing used in the above study and derived from the aloe plant (Carrasyn Gel Wound Dressing, Carrington Laboratories, Irving, TX) is approved by the U.S. Food and Drug Administration for the management of mild to moderate skin ulcers.

Aloe vera juice has anti-inflammatory activity and been used by some doctors for people with UC. In a double-blind study of people with mildly to moderately active ulcerative colitis, supplementation with aloe resulted in a complete remission or an improvement in symptoms in 47% of cases, compared with 14% of those given a placebo (a statistically significant difference).¹⁴ No significant side effects were seen. The amount of aloe used was 100 ml (approximately 3.5 ounces) twice a day for four weeks. Other traditional anti-inflammatory and soothing herbs, including calendula, flaxseed, licorice, marshmallow, myrrh, and yarrow. Many of these herbs are most effective, according to clinical experience, if taken internally as well as in enema form.¹⁵ Enemas should be avoided during acute flare-ups but are useful for mild and chronic inflammation. It is best to consult with a doctor experienced with botanical medicine to learn more about herbal enemas before using them. More research needs to be done to determine the effectiveness of these herbs.

In animal studies of skin inflammation, both topical and oral aloe vera have proven beneficial in decreasing inflammation and promoting cellular repair.^{16, 17} Topical aloe vera has facilitated wound healing in controlled human research, as well.¹⁸ In one controlled trial, however, topical aloe vera gel was inferior to conventional management of surgical wounds.¹⁹

A variety of anti-inflammatory herbs historically have been recommended by doctors for people with Crohn’s disease. These include yarrow, chamomile, licorice, and aloe juice. Cathartic preparations of aloe should be avoided. No research has been conducted to validate the use of these herbs for Crohn’s disease.

Other herbs traditionally used to treat reflux and heartburn include digestive demulcents (soothing agents) such as aloe vera, slippery elm, bladderwrack, and marshmallow.²⁰ None of these have been scientifically evaluated for effectiveness in GERD. However, a drug known as Gaviscon, containing magnesium carbonate (as an antacid) and alginic acid derived from bladderwrack, has been shown helpful for heartburn in a double-blind trial.²¹ It is not clear whether whole bladderwrack would be as useful as its alginic acid component.

Topical aloe (Aloe vera) is often recommended for soothing burns, but only one preliminary human study involving sunburn has been published, and applying aloe gel after ultraviolet exposure had no effect on reddening of the skin.²² No research has investigated whether applying aloe gel before ultraviolet exposure might be more effective.