The Many Sides of Aloe

Aloe vera has long been used as a powerful healing plant in medicinal traditions in India, China and Africa, as well as an external and internal beauty aid for Egyptian royalty. But its market potential is still tremendous in the Western world.

“Aloe has exponentially increased in functional uses over the past decade,” said Bill Neal, Eastern regional sales manager, Terry Labs. “New horizons are being discovered constantly for one of nature’s oldest and most reliable alternatives to modern medicine.”

According to Barb Apps, director of business development and marketing, AloeCorp, studies over the past 20 years support aloe’s ancient uses as a digestive tonic, blood sugar regulator, detoxifying agent, healthy skin promoter, organ protector and overall body tonic.

Aloe vera, a member of the lily family, has a cactus-like appearance and varies in color, from bright green to grey. It is found in warm, dry climates in Africa, Asia, South and Central America, Southern Europe, the Caribbean and other tropical areas. The two main components of aloe are the gel, found inside the leaves, and the exudate, which comes from the juice obtained from the cells beneath the skin. The gel portion of the plant contains many active constituents, including amino acids, vitamins, minerals, mineral salts, plant hormones and sterols, enzymes, aromatic acids and polysaccharides.¹

Digestive Health

The internal use of aloe has a storied history, according to Robert A. Sinnott, Ph.D., senior vice president for research and development and chief science officer, Mannatech Inc. “Aloe was used internally, thousands of years ago; it’s a great laxative and diuretic,” he said. “It’s had a variety of gastrointestinal (GI) tract uses throughout history. More recently, research is starting to show that some of the compounds that are in the polysaccharides that are in aloe are specific anti-microbial compounds. It’s turning out that they’re particularly good at regulating the bacteria that grows within your GI tract.”

According to Apps, aloe can be used as a GI tonic, to relieve the pain of peptic ulcers, soothe indigestion and flatulence, help heal gastric lesions and prevent damage to the GI system. It may even ease the symptoms of irritable bowel syndrome (IBS), she added, noting further investigation is needed.

In a 2006 study, researchers at Chulalongkorn University, Bangkok, compared the effects of aloe vera and sucralfate on gastric microcirculatory changes, cytokine levels and gastric ulcer healing in rats.² In the ulcer groups treated with sucralfate and aloe on days 1 and 8, gastric inflammation was reduced, epithelial cell proliferation was enhanced and gastric glands became elongated. The ulcer sizes were also reduced compared to the ulcer group without treatment. It was concluded that aloe vera treatment can reduce leukocyte adherence and tumor necrosis factor (TNF)- alpha levels, elevate interleukin-10 (IL-10) levels and promote gastric ulcer healing.

Because of aloe’s soothing and anti-inflammatory properties, researchers at the Institute of Cellular and Molecular Science, London, studied the effects of aloe on inflammatory IBS.³ Forty four subjects with IBS were randomly given oral aloe vera gel or a placebo twice daily for four weeks and changes in the Simple Clinical Colitis Activity Index (SCCAI) were measured. The SCCAI and histological scores decreased significantly during treatment with aloe vera. The researchers concluded oral aloe vera produced a clinical response more often than placebo; aloe vera also reduced the histological disease activity and appeared to be safe. Similarly, researchers at St. George’s Hospital medical school, London, assessed the ef ficacy of aloe vera on IBS.⁴ Patients were randomized to receive either aloe vera or a placebo for a month. Diarrhea predominant patients showed a trend toward a response to treatment, but there was no evidence that aloe vera benefited patients with IBS.

Diabetes Fighter

Aloe vera also appears to possess anti-diabetic activity, helping to lower blood sugar and triglyceride levels, which are often high in diabetic patients. Researchers at the Mahidol Medical University, Bangkok, gave subjects one tablespoon of aloe vera juice, twice daily.⁵ After only two weeks, blood sugar levels had normalized and triglyceride levels were reduced. The researchers conducted a follow-up trial with aloe to determine the effect of treatment in patients unresponsive to glibenclamide, an anti-diabetic medication.⁶ The levels of fasting blood glucose, cholesterol and triglycerides remained stagnant when subjects solely used glibenclamide. Those who had used aloe juice saw a 48 percent decrease in blood sugar levels and a 52 percent decrease in triglycerides.

Animal studies provide further supporting evidence for aloe’s anti-diabetic properties. A 2005 study from the University of Zimbabwe induced diabetes in rats and then administered aloe powder.⁷ Results showed aloe had significant activity on glucose levels. A similar study from the University of Madras, India, examined the ef fect of aloe vera gel on membrane-bound phosphates and lysosomal hydrolases in the liver and kidney of diabetic rats.⁸ After 21 days, aloe had significantly restored the alterations in enzyme activity to near normalcy. Researchers confirmed aloe possesses a significant beneficial effect on membrane-bound phosphatases and lysosomal hydrolases. Yet another study showed aloe can have a long-term blood glucose level control effect.⁹ Researchers at the Morinaga Milk Industry Co., Japan, studied type 2 diabetic mice that were being treated with aloe vera gel. There were significant decreases of 15 to 18 percent in the hemoglobin A1c levels, and severely diabetic mice treated with phytosterols derived from aloe vera gel did not suffer weight reduction due to glucose loss in urine.

Combatting Cancer

Perhaps one of the most active areas of scientific investigation is aloe’s effect on cancer. According to Gillian McKeith, Ph.D., author of Living Food for Health: “The efficacy of aloe’s potent immunostimulant glucomannan has been approved for veterinary use in injectible form for fibrosarcomas and feline leukemia.” In one study, 44 cats, all diagnosed with feline leukemia, were injected with 2 mg of glucomannan weekly for six weeks, and reexamined six weeks after termination of the treatment.¹⁰ Three-quarters (77 percent) of the cats were alive at the end of the 12 week study, which McKeith called significant, as 70 percent of cats will die within eight weeks of diagnosis. The glucomannan from aloe was credited with significant anti-viral, immunostimulant, and bone marrow-stimulating properties by the researchers.

Another study examined the effects of aloe vera leaf pulp on certain tumors.¹¹ Mice with implanted Ehrlich ascites tumors were injected with 55 mg of aloe extract twice a week for 21 days. Tumor size, thymus and spleen weights were measured, as well as leucocyte count, TNF-alpha and sialic acid as tumor markers. Researchers found the best inhibitory effect on tumor growth was obtained with the extract given prophylactically before tumor implantation, although aloe extract also regressed tumor sizes when given simultaneously with, or therapeutically after, tumor implantation. It was concluded aloe has tumor preventive properties due to its immunomodulatory activity. They added aloe could be proposed as a prophylactic for cancer prevention. The same researchers did another study several months later, using the main lectin present in aloe, Aloctin I, on Ehrlich ascites tumors in mice.¹² The lectin administered before tumor implantation regressed tumor size, but was less potent than the leaf pulp used in the previous study.

Studies have also examined human cancers. Researchers at the San Gerardo Hospital, Italy, treated 50 patients suffering from lung cancer, GI tract tumors, breast cancer or brain glibolastoma.¹³ Aloe was given in conjunction with pineal indole melatonin (MLT). Results showed the percent of one year survival was significantly higher in patients treated with MLT plus aloe. According to the researchers, the data suggests natural cancer therapy with MLT and aloe may produce some therapeutic benefits, in terms of stabilization of disease and survival, in patients with advanced solid tumors, for whom no other standard effective therapy is available. Another study looked at the effect of aloe on the growth of human cervical cancer cells.¹⁴ The cells were treated with various concentrations of aloe and cell growth was measured. Aloe inhibited the growth of the cancer cells in a dose-dependent manner.

Challenges in Using Aloe

In the aloe processing industry, not all aloe is created equally: quality and potency are extremely important for manufacturers. “The quality of aloe varies tremendously, depending on how it’s processed and how it is stored,” Sinnott said. “Getting really high quality aloe preparations is an ongoing challenge. We screen dozens of different aloe sources a year. The reason quality varies is that, the longer you store it or the longer you process it, the beneficial compounds, like the polysaccharides, tend to degrade; they break down.”

He added there are also problems with certain components in aloe. “There is another issue with aloe in that there’s a compound in aloe called anthroquinone, and it can be toxic in larger concentrations, and so there are limits on the amount of an throquinone that can be used inorally-ingested aloe preparations,” he said.

According to Bill Pine, vice president of sales and marketing, Improve USA, in order to guarantee the safety and effectiveness of aloe products, buyers should look for the seal of approval from the International Aloe Science Council (IASC). “This will ensure that consumers are purchasing aloe that meets the high standard established by the industry for efficacious benefits to the consumer,” Pine said.

Aloe also tends to vary in flavor from harvest to harvest, Apps noted. “Additionally, there is a slight salty and earthy flavor that requires masking and a sweetener to be palatable for a mass market-type consumer,” she said. However, it is fairly easy to mask the flavor and offer consumers a wide range of flavors, “from fruit to chocolate to tea, coffee or mint,” she added.

The actual process of incorporating aloe into formulations tends to have minimal challenges, because it acts as a “nanoparticle,” said Patrick Anderson, Western regional sales manager, Terry Labs. “It penetrates topically easily, as well as being very effective internally. Due to its water solubility, it is an excellent ingredient in any formulation.”

Aloe in Different Forms

“The majority of aloe sales are from products in beverage form, which follows the pattern of traditional use throughout the world,” Apps said. AloeCorp has also developed dehydrated aloe flakes, which, according to Apps, has superior stability and nutrient retention for two years, can be easily dispersed throughout formulas, and tastes the same as fresh-squeezed aloe upon reconstitution.

Improve USA has also formulated a dehydrated aloe powder, DaltonMax 700. “The powder retains all the natural components found in the fresh leaf, including the very large polysaccharides,” Pine said.

The growing base of research about aloe’s health benefits is also attracting interest from the new quarters, “especially with the ‘beauty from within’ segment, playing off of aloe’s well-known topical benefits for the skin,” Apps noted. She added that in Europe and Asia, aloe vera can be found in many food products, such as yogurt, chewing gum and wine, as well as a “fresh-cubed aloe inner fillet, which can be found in a store’s refrigerated section, to be used at home to make freshly prepared foods.”

Anderson said there has been a rapidly growing interest from manufacturers looking at how aloe will function with other food, drink and supplement ingredients. He added: “Aloe will always be used in supplements and beverages. The question is how will aloe position itself within the upcoming market strategies, such as functional foods and beverages. With the research that has been done on aloe over the years, aloe is a perfect fit for nutritional bars, functional beverages, foods and supplements.”

References

1. McKeith, Gillian. Living Food For Health: 12 Natural Superfoods to Transform Your Health. North Bergen, NJ: Basic Health Publications Inc. 2005

2. Eamlamnam K. “Effects of Aloe vera and sucralfate on gastric microcirculatory changes, cytokine levels and gastric ulcer healing in rats.” World J Gastroenterol. 2006;12(13):2034-9.

3. Langmead L. “Randomized, double-blind, placebo-controlled trial of oral aloe vera gel for active ulcerative colitis.” Ailment Pharmacol Ther. 2004;19(7):739-47.

4. Davis K. “Randomised double-blind placebo-controlled trial of aloe vera for irritable bowel syndrome.” Int J Clin Pract. 2006;60(9):1080-6.

5. Bunyapraphatsara N. “Antidiabetic activity of aloe vera L juice II. Clinical trial in diabetes mellitus patients in combination with gilbenclamede.” Phytomedicine. 1996;3(3):245-8.

6. Sun-A Im. Int Immunopharmacol. 2005;5:271-9.

7. Gundidza M. “Anti-diabetic activity of aloe excelsa.” Cen Afr J Med. 2005;51(11-12):115-20.

8. Rajasekaran S. “Effect of aloe vera lead gel extract on membrane bound phosphatases and lysosmal hydrolases in rats with streptozotocin diabetes.” Pharmazie. 2007;62(3):221-5.

9. Tanaka M. “Identification of five phytosterols from aloe vera gel as anti-diabetic compounds.” Biol Pharm Bull. 2006;29(7):1418-22.

10. Sheets MA. “Studies of the effect of acemannan (tradename) on retrosirius infections; clinical stabilization of feline leukemia virus-infected cats.” Mol Biother. 1991;3(1):41-5.

11. Akev N. “Effect of Aloe vera leaf pulp extract on Ehrlich ascites tumours in mice.” Eur J Cancer Prev. 2007;16(2):151-7.

12. Akev N. “Tumour preventive effect of Aloe vera leaf pulp lectin (Aloctin I) on Ehrlich ascites tumours in mice.” Phytother Res. 2007;21(11):1070-75.

13. Lissoni P. “Biotherapy with the pineal immunomodulating hormone melatonin versus melatonin plus aloe vera in intreatable advanced solid neoplasms.” Nat Immun. 1998;16(1):27-33.

14. Guo JM. “Anti-cancer effect of aloe-emodin on cervical cancer cells involves G2/M arrest and induction of differentiation.” Acta Pharmacol Sin. 2007;28(12):1991-5.