ALOE VERA

 Botanical names: Aloe vera, Aloe barbadensi

 Aloe vera  is a species of Aloe, native to northern Africa. A stemless or very short-stemmed succulent  plant, it grows up to one metre in heightl, spreading by offsets and root sprouts. Its lanceolate leaves are thick and fleshy, green to grey-green, with a serrated border. The flowers are produced on a spike up to 90 cm tall, each flower pendulous, with a yellow tubular corolla  2–3 cm long.

Historical or traditional use

Aloe has been traditionally used:                                                                                                              

·        Cosmetic companies add sap or other derivatives from Aloe vera to products such as makeup, tissues, moisturizers, soaps, sunscreens, shampoos and lotions, though the effectiveness of Aloe vera in these products remains unknown. Aloe vera gel is also alleged to be useful for dry skin conditions, especially eczema around the eyes and sensitive facial skin. Most suppliers, however, degrade the polysaccharides during processing (Turner et al, 2004).

Active ingredients

The components of aloe  responsible for its laxative effects are known as anthraquinone glycosides which are split by the normal bacteria in the large intestines to form other molecules (aglycones), which have a laxative action.

It is uncertain which components are responsible for the wound healing properties of aloe. In vitro studies suggest polysaccharides, such as acemannon, help promote skin healing by anti-inflammatory, antimicrobial, and immune-stimulating actions. Aloe has a high concentration of amino acids and other nutrients including, as well as vitamin E, vitamin C, zinc, and essential fatty acids which may aid wound healing.

Effects and Supporting Evidence

In the Mayo Clinic Patient  Monograph on Aloe Vera it is stated: “There is strong scientific evidence in support of the laxative properties of aloe latex, based on the well-established cathartic properties of anthroquinone glycosides (found in aloe latex).(Mayo Clinic,2007)

In laboratory studies aloe vera has antibacterial properties against a range of bacteria, which supports claims that aloe vera is useful for minor skin infections. Aloe vera demonstrated antibacterial activity against Corynebacterium, Salmonella, Streptococcus, S. aureus. (Cowan 1999)

Two small controlled human trials have found that aloe, either alone or in combination with the oral hypoglycemic drug, glibenclamide, effectively lowers blood sugar in people with type 2 (non-insulin-dependent) diabetes. (Yongchaiyudha et al ,1996; Bunyapraphatsara et al 1996)

An aloe extract in a cream has been shown effective in a double-blind, controlled trial in people with psoriasis. (Syed et al 1996)

Dose

·        For constipation, a single 50–200 mg capsule of aloe latex can be taken each day for a maximum of ten days.

·        For skin conditions, the stabilized aloe gel is applied topically to the affected area of skin three to five times per day. If no improvement is observed after 48hours of use, advice or worsening of the condition occurs. Treatment of more serious burns should only be done under the supervision of a healthcare professional.

·         For internal use of aloe gel, two tablespoons (30 ml) three times per day is used by some people for inflammatory bowel conditions, such as Crohn’s disease and ulcerative colitis, The latex form of aloe should NOT be used by anyone with inflammatory intestinal diseases, such as Crohn’s disease, ulcerative colitis.

·         For type 2 diabetes, clinical trials have used one tablespoon (15 ml) of aloe juice, twice daily. Treatment of diabetes with aloe should only be done under the supervision of a medical practitioner..

 Side effects

Except in the rare person who is allergic to aloe, topical application of the gel is generally safe. For any burn that blisters significantly or is otherwise severe(eg large size, excessive pain, fever, loss of sensation to affected area), medical attention is absolutely essential. In some severe burns and wounds, aloe gel may actually impede healing.⁹

In people with constipation, aloe latex should not be used for more than ten consecutive days as it may lead to dependency and fluid loss. Extensive fluid loss may lead to depletion of important electrolytes in the body such as potassium¹¹

Interactions
Diabetics taking the sulfonylurea drug glibenclamide should not use aloe vera without close supervision by a medical practitioner..

References

1. Penneys NS. Inhibition of arachidonic acid oxidation in vitro by vehicle components. Acta Derm Venerol Stockh 1981;62:59–61.

2. Visuthikosol V, Chowchuen B, Sukwanarat Y, et al. Effect of Aloe vera to healing of burn wound: A clinical and histologic study. J Med Assoc Thai 1995;78:403–9.

3.Cowan M. Plant Products as Antimicrobial Agents. Clinical Microbiological Reviews 1999 p. 564-582, Vol. 12, No. 4

4. Turner, CT, Williamson, DA, Stroud, PA, Talley, DJ. (2004). Evaluation and comparison of commercially available Aloe vera L. products using size exclusion chromatography with refractive index and multi-angle laster light scattering detection. International Immunopharmacology 4: 1727-1737.

5. Visuthikosol V, Chowchuen B, Sukwanarat Y, et al. Effect of aloe vera gel in the healing of burn wound: a clinical and histologic study. J Med Assoc Thai 1995;78:403–9.

6. Williams MS, Burk M, Loprinzi CL, et al. Phase III double-blind evaluation of an Aloe vera gel as a prophylactic agent for radiation-induced skin toxicity. Int J Rad Oncol Biol Phys 1996;36:345–9.

7. Yongchaiyudha S, Rungpitarangs V, Bunyapraphatsara N, Chokechaijaroenporn O. Antidiabetic activity of Aloe vera L. juice. I. Clinical trial in new cases of diabetes mellitus. Phytomedicine 1996;3:241–3.

8. Bunyapraphatsara N, Yongchaiyudha S, Rungpitarangsi V, Chokechaijaroenporn O. Antidiabetic activity of Aloe vera L juice. II. Clinical trial in diabetes mellitus patients in combination with glibenclamide. Phytomedicine 1996;3:245–8.

9. Syed TA, Ahmad SA, Holt AH, et al. Management of psoriasis with Aloe vera extract in a hydrophilic cream: a placebo-controlled double-blind study. Trop Med Int Health 1996;1:505–9.