Written by Edzard Ernst and the CAM-Cancer Consortium.
Updated March 20, 2013

Aloe vera

What is it?

Description

Aloe vera is a cactus-like plant with a long history of medicinal use.

Scientific name

Aloe vera, Aloe barbadensis.

Ingredients

Aloe vera gel which is made of the mucilaginous tissue from the centre of the Aloe vera leaf contains polysaccharides. Aloe vera latex (the form taken orally), which is made of the peripheral bundle sheath cells contains aloin, anthraquinones, barbaloine and glycosides1.

Application and dosage

Gel is applied topically as needed. Latex is taken orally at doses between 50 and 200mg daily1.

History

Aloe vera has been used medicinally in many medical cultures. Today it is available as over-the-counter products and used by a range of healthcare professionals e.g. doctors, nurses, herbalists, naturopaths, nutritionists.

Claims of efficacy

Traditionally, Aloe vera has been used for a very wide range of conditions. In oncology, the main claim is that topical application of the gel prevents or treats radiation-induced skin reactions2.

Mechanisms of action

A multitude of potential mechanisms of action has been identified2. In vitro experiments have suggested that constituents of Aloe vera, such as aloin, exhibit anti-cancer effects through anti-angiogenic and cytotoxic activities3-5. Animal experiments have demonstrated detoxification of carcinogens,6 reduction of papilloma growth in mice7,8. and chemopreventive effects through modulating antioxidant and detoxification enzyme activity9.

Aloe vera latex is a powerful laxative. Aloe vera gel has antimicrobial, antioxidant, antiproliferative, chemo-preventive, anti-inflammatory, moisturising and antipuritic actions1,10,11. Anthraquinones of Aloe vera latex also have cytotoxic, radioprotective as well as antiangiogenic effects and inhibit angiogenic and metastatic regulatory processes12,13. In addition, aloin may Aloin enhance cisplatin antineoplastic activity in B16-F10 melanoma cells14. Whole leaf extract of Aloe vera has been shown in animal experiments to have carcinogenic potential 4.

Alleged indications

In oncology, the main indication for Aloe vera is the application of the gel for radiation-induced skin irritation, as well as to prevent or treat cancer.

Prevalence of use

Generally speaking, Aloe vera products are very popular, particularly for self-treatment and for cosmetic use. Most healthcare professionals caring for cancer patients are aware of the claim that Aloe vera gel reduces skin inflammation, and many recommend it to their patients. Precise prevalence figures are not available.

Legal issues

Aloe vera products are sold as cosmetics or as herbal supplements.

Cost and expenditure

High quality products are widely available and usually inexpensive. A typical week’s supply of Aloe vera gel would cost less than €6.

Citation Edzard Ernst, CAM-Cancer Consortium. Aloe vera [online document]. http://ws.cam-cancer.org/The-Summaries/Herbal-products/Aloe-vera. March 20, 2013.

References

  1. Ernst E, Pittler MH, Wider B, Boddy K. The Desktop Guide to Complementary and Alternative Medicine. 2nd edition. Edinburgh: Elsevier Mosby. 2006.
  2. Ulbricht C, Armstrong J, Basch E, Basch S, Dacey C, Dalton S et al. An evidence-based systematic review of Aloe vera by the Natural Standard Research Collaboration. J Herb Pharmacother 2007; 7(3-4):279-323.
  3. Cárdenas C, Quesada AR, Medina MA. Evaluation of the anti-angiogenic effect of Aloe-emodin. Cell Mol Life Sci 2006; 63(24):3083-3089.
  4. Xiao B, Guo J, Liu D, Zhang S. Aloe-emodin induces in vitro G2/M arrest and alkaline phosphatase activation in human oral cancer KB cells. Oral Oncol 2007; 43(9):905-910.
  5. Esmat AY, Tomasetto C, Rio MC. Cytotoxicity of a natural anthraquinone (Aloin) against human breast cancer cell lines with and without ErbB-2: topoisomerase IIalpha coamplification. Cancer Biol Ther 2006; 5(1):97-103.
  6. Singh RP, Dhanalakshmi S, Rao AR. Chemomodulatory action of Aloe vera on the profiles of enzymes associated with carcinogen metabolism and antioxidant status regulation in mice. Phytomed 2000; 7(3):209-219.
  7. Saini M, Goyal PK, Chaudhary G. Anti-tumor activity of Aloe vera against DMBA/croton oil-induced skin papillomagenesis in Swiss albino mice. J Environ Pathol Toxicol Oncol 2010; 29(2):127-135.
  8. Chaudhary G, Saini MR, Goyal PK. Chemopreventive potential of Aloe vera against 7,12-dimethylbenz(a)anthracene induced skin papillomagenesis in mice. Integr Cancer Ther 2007; 6(4):405-412.
  9. El-Shemy HA, Aboul-Soud MA, Nassr-Allah AA, Aboul-Enein KM, Kabash A, Yagi A. Antitumor properties and modulation of antioxidant enzymes' activity by Aloe vera leaf active principles isolated via supercritical carbon dioxide extraction. Curr Med CHem 2010; 17(2):129-138.
  10. Richardson J, Smith JE, McIntyre M, Thomas R, Pilkington K. Aloe vera for preventing radiation-induced skin reactions: a systematic literature review. Clin Oncol 2005; 17:478-484.
  11. Su CK, Mehta V, Ravikumar L, Shah R, Pinto H, Halpern J et al. Phase II double-blind randomized study comparing oral Aloe vera versus placebo to prevent radiation-related mucositis in patients with head-and-neck neoplasms. Int J Radiat Oncol Biol Phys 2004; 60:171-177.
  12. Lissoni P, Giana L, Zerbini S, Trabattoni P, Rovelli F. Biotherapy with the pineal immunomodulating hormone melatonin versus melatonin plus Aloe vera in untreatable advanced solid neoplasms. Nat Immun 1998; 16:27-33.
  13. Suboj P, Babykutty S, Valiyaparambil Gopi DR, Nair RS, Srinivas P, Gopala S. Aloe emodin inhibits colon cancer cell migration/angiogenesis by downregulating MMP-2/9, RhoB and VEGF via reduced DNA binding activity of NF-kappaB. Eur J Pharm Sci 2012; 45(5):581-591.
  14. Tabolacci C, Rossi S, Lentini A, Provenzano B, Turcano L, Facchiano F et al. Aloin enhances cisplatin antineoplastic activity in B16-F10 melanoma cells by transglutaminase-induced differentiation. Amino Acids 2013; 44(1):293-300.
  15. Worthington HV, Clarkson JE, Bryan G, Furness S, Glenny AM, Littlewood A et al. Interventions for preventing oral mucositis for patients with cancer receiving treatment. Cochrane Database Syst Rev 2011;(4):CD000978.
  16. George J. To assess the effectiveness of aloe vera gel in preventing skin reactions associated with radiotherapy. Indian Journal of Palliative Care 2011; 17:91-103.
  17. Sudarshan R, Annigeri RG, Sree VG. Aloe vera in the treatment for oral submucous fibrosis - a preliminary study. J Oral Pathol Med 2012; 41(10):755-761.
  18. Lissoni P, Rovelli F, Brivio F, Zago R, Colciago M, Messina G et al. A randomized study of chemotharpy versus biochemotherapy with chemotherapy plus Aloe arborescens in patients with metastic cancer. In Vivo 2009; 23:171-176.
  19. Puataweepong P, Chanachai M, Dangprasert S, Sithatani C, Sawangsilp T, Narkwong L et al. The efficacy of oral Aloe vera juice for radiation induced mucositis in head and neck cancer patients: a double-blind placebo-controlled study. Asian Biomed 2009; 3(4):375-382.
  20. Sakai R. Epidemiologic survey on lung cancer with respect to cigarette smoking and plant diet. Jpn J Cancer Res 1989; 80(6):513-520.
  21. Yokohira M, Matsuda Y, Suzuki S, Hosokawa K, Yamakawa K, Hashimoto N et al. Equivocal colonic carcinogenicity of Aloe arborescens Miller var. natalensis berger at high-dose level in a Wistar Hannover rat 2-y study. J Food Sci 2009; 74(2):T24-30.
  22. National Toxicology Program. Photocarcinogenesis Study of Aloe vera [CAS NO. 481-72-1(Aloe-emodin)] in SKH-1 Mice (Simulated Solar Light and Topical Application Study). Natl Toxicol Program Tech Rep Ser 2010; Sep(553):1-206.