So what is aloe ferox, anyway?
Aloe Ferox is a plant native to South Africa. It's similar to Aloe Vera, but has many times more nutritional and medicinal value than aloe vera.
Over 130 biological active compounds of the aloe ferox have so far been reported. The Aloe ferox leaf contains substances such as amino
How do I use these products?
Each Aloe Ferox product has a list of directions for use. Also, read our pamphlet, "Eat Yourself Slim" which contains other helpful tips.
Disclaimer: Please note that our statements about the healing properties of aloe ferox are not evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease. For your best health, in the case of recurring and long-term illness, you should consult your doctor. You should also consult your doctor before using herbal remedies if you have an existing health condition, are pregnant or are planning to have a baby. No studies have been concluded on internal use of aloe in children.
WHAT YOU MUST KNOW WHEN USING HERBS LIKE ALOE FEROX
Pharmacy in a Plant Aloe ferox is among the tallest of the more than 400 aloe species and is native to southeastern and western regions of South Africa. Compared to the more widely known Aloe vera, Aloe ferox produces 20 times more bitter sap and has higher nutrient concentrations. Two distinct parts of the aloe plant are used medicinally. Firstly the aloe exudate (bitter sap) and secondly the mucilaginous gel from the remainder of the leaf. The aloe bitter is best known for its use as a laxative. However, in addition to the purgative effect the anthraquinone (bitter) substance is also an antioxidant, antiviral and effective for cancer prevention.
Numerous scientific studies on aloe gel are demonstrating its analgesic, anti-inflammatory, wound healing, immune modulating and anti-tumour activities as well as antiviral, anti-bacterial, antifungal and antiviral properties. The aloe juice has been shown to lower cholesterol and triglycerides while demonstrating anti-diabetic activity. Aloe’s medicinal properties can be attributed to the synergistic effect of the combined nutritional elements producing a more powerful effect than the individual components. Aloes are members of the Liliaceae family and are mainly succulents. The nearly 420 species of Aloe are confined mainly to Africa with Aloe ferox among the tallest. Aloe ferox occurs naturally in a broad belt along the southern and eastern coast of South Africa. Aloe ferox is a robust, single stemmed, plant usually 2m (80”) high, but up to 5m (200”) tall in older specimens. They have broad, fleshy leaves that are dull green to greyish green with brown spines along the edges. The dry leaves are persistent on the lower portion of the stem. Bright red or orange flowers appear from May to August and are arranged in erect, candle-shaped clusters (Van Wyk 2003).
Pollination is by bees and nectar seeking birds and propagates with ease. New plants reach maturity (to flower and set seed) within four to six years. Under favourable conditions plants may become in excess of 50 years old. Aloe ferox is not considered an endangered species. It is not listed on the United States Endangered Species Act list. Neither is it listed on the internationally maintained Red List of Threatened Species or on the CITES list of endangered species. All broad leaf Aloe species have basically the same leaf structure. A tough green outer layer encloses the translucent fleshy portion of the leaf.
There are two distinct parts of the plant that are harvested. Firstly the yellow exudate (better known as the bitter sap), which drains from the outer green skin of the leaves when cut, and the remainder of the leaf that contains the mucilaginous gel. The traditional method of harvesting the leaves is still performed as practiced for more than 200 years. The aloe is harvested by cutting 4 to 8 of the lower leaves from the plant. Roughly 200 leaves are stacked in a circle to allow the yellow bitter sap to drain from the leaves. The bitter sap is collected and boiled to remove excess water to produce the bitter crystals.
The harvested leaves are processed at the factory to manufacture the aloe gel and juice. Aloe bitters: (Viljoen 1999, Van Wyk 1995) Anthrones and chromones are the two major classes of compounds, which are found in leaf exudates (22% – 29%) Anthrones: aloin and barbaloin (collective name for aloin A and B) Chromones: aloesin and aloeresin A. Anthraquinones, naphthalene, alkaloids and various other compounds may be present. Aloe gel: (Mabusela 1990) Primary constituents are glucomannoglycan polysaccharides containing acetylated monosaccharides. (~70-80%) Acemannan (mannose) and glucomannan (glucose). Other constituents: Amino acids. (10-15%) Salicylic acid, lignin, saponins and sterols. Fatty acids (gamma-linolenic acid [GLA]). Enzymes, vitamins and minerals. A comparison of the chemical composition of Aloe ferox and Aloe vera was performed based on values available in the literature (Femenia 1999, Mabusela 1990). It must be noted, however, that concentrations tend to vary seasonally and geographically (Grindlay 1986).
The different monosaccharide components of the polysaccharides present in the Aloe ferox and Aloe vera gel are compared (expressed as mol%). Similarly, scientific tests comparing the differences between Aloe ferox and Aloe vera plants (whole leafs), growing side by side, were performed at the Kirstenbosch National Botanical Garden in Cape Town, South Africa. (Jan. ’87) The tests demonstrated the following: The freshly cut leaf of Aloe ferox produced approximately 20 times more bitter sap, weight by weight, than the Aloe vera. Aloe vera has a much softer and more translucent inner gel. It is also notably more mucinous.
After extraction, the juice of the Aloe vera leaves decolourizes and loses its viscosity much more rapidly than does the juice of Aloe ferox. The solids content of the juice in Aloe ferox were constantly greater in volume than those obtained from Aloe vera. The amino acid content of Aloe ferox is almost double that of Aloe vera (see table). Aloe ferox and Aloe vera contain 7 of the 8 essential (** in table) amino acids and all the other 12 non-essential amino acids. Similarly the mineral concentrations of Aloe vera (Femenia 1999) were compared to typical concentration measured in Aloe ferox (expressed as % of dry matter). It is evident that Aloe ferox contains a higher concentration of these minerals, which can potentially ascribed to its harvesting in its natural habitat and not in domesticated fields. As can be seen the chemical composition of Aloe vera is comparable to that of Aloe ferox.
The healing properties of aloe have been known for millennia. The use of aloe was discovered on a Mesopotamian clay tablet (ca. 2100 BC). Aloes were listed in the Ebers papyrus (ca. 1500 BC) as an established cathartic. Legend has it that aloe was an important part of the beauty regimen of the Egyptian queens, Nefertiti and Cleopatra. The Greek physician Dioscorides, while accompanying Nero’s army, mentioned aloe in his writing (ca 100 AD). Alexander the Great (356–323 BC) was persuaded by Aristotle to capture the island of Socrota in the Indian Ocean to secure its aloe A. perryi supplies to treat his wounded soldiers (Bruce 1975). Numerous Aloe species have been used medicinally but only Aloe ferox, Aloe perryi and Aloe vera have demonstrated any commercial importance (Grindlay 1986). Scientific literature now documents various medical applications. Aloe gel has demonstrated anti-inflammatory (Vázquez 1996, Bautista 2004), wound healing (Davis 1989, 1994, Heggers 1996), anti-tumour (Kim 1999, Pecere 2000), antiviral (McDaniels 1990a,b), anti-microbial (Wang 1998) and anti-diabetic (Reynolds 1999) activity. It has also shown immune stimulating (Zhang 1996, Strickland 2001) and cholesterol lowering activity (Tizard 1989). The active constituent in the aloe exudate (bitter) is the anthrones. They are degraded in the colon by bacteria to aloe-emodin, which function as a stimulant laxative (Blumenthal, 1998). Studies have also demonstated aloe-emodin to be antiviral (Sydiskis 1991), an antioxidant (Yen, 2000), effective for liver cancer prevention (Kuo 2002) and inhibits neuroectodermal (embryonic tissue that gives rise to nerve cells) tumor cell growth (Pecere 2000). Anti-inflammatory Inflammation is a non-specific immune response by the body to any type of injury. It is characterized by redness (rubor), heat (calor), swelling (tumor) and pain (dolor). According to Clayton (1993) the steps in inflammation are: vasodilation that reduces blood pressure and increases blood flow (causing redness and heat) followed by swelling due to an excessive amount of tissue fluid (increased vascular permeability enables blood to move out of the capillaries into the tissue) and pain (due to bradykinin, stimulates prostaglandin production and accumulation in inflammatory cells as macrophages). Vázquez (1996) demonstrated the anti-inflammatory effect of aloe gel. It inhibited prostaglandin E2 production from arachidonic acid. While Yagi (1982) showed that the glycoprotein of aloe gel cleaved the bonds of the bradykinin molecule reducing pain and inflammation. In a later study (Bautista 2004) the antibradykinin effect was associated with the inhibition of prostaglandin synthesis.
Inflammation is also involved in conditions such as arthritis. Rheumatoid arthritis closely resembles adjuvant arthritis in rats and was studied by Davis (1992). According to this experiment aloe was injected and decreased inflammation (50%) and stimulated fibroblast growth repair. Hanley (1982) showed when rat paws were injected with A. ferox it decreased inflammation (48%) and inhibited the immune response (72%) [possibly due to inhibition of prostaglandin synthesis]. A subsequent study (Davis 1985) showed that when A. ferox was applied topically in a hydrophilic cream it reduced inflammation (39%) and subsequent arthritis (45%). It has also been found that aloe has analgesic properties that can be ascribed to the presence of salicylates, which has an aspirin like effect (Shelton 1991).
Wound healing A wound to the skin may pierce two layers, the dermis and epidermis. Healing follows the following steps (Reynolds 1999) by: temporary repair is effected by fibrin clot (granulation tissue) to fill the gap which is invaded by cells that produce the inflammatory response and carry out the permanent repair. The epidermis is repaired in 3 phases: (Davis 1994) fibroblasts migrate to the wound site causing granulation tissue to fill the gap, they proliferate and mature to produce collagen, elastin and proteoglycans. Proteoglycans form the basis in which collagen and other connective fibres are embedded. (new connective tissue is found in the dermis) It is essential to avoid microbial infection, as this will retard wound healing.
Wounds treated with aloe showed rapid granulation and increased oxygen supply as a result of the increased blood flow (Davis 1989). The skin punch wounds healed more rapidly. The aloe gel reduced wound diameter, seemed to reduce scarring and inhibited acute inflammation. In another study, (Heggers 1996) stimulation of fibroblast activity and collagen proliferation was demonstrated. Aloe also expedites wound contraction and enhanced wound breaking strength. Choi (2001) isolated a glycoprotein from Aloe vera that stimulated the formation of epidermal tissue. It also enhanced wound healing with significant cell proliferation and migration. In the treatment of burn wound Heggers (1993) showed that the gel penetrated the tissue, relieve pain, reduce inflammation and increase blood supply by inhibiting the synthesis of thromboxane A2, a potent vasoconstrictor. (Gel delays the inflammatory response and speeds up recovery time for first and second degree burns)
A recent study (Barrantes 2003) demonstrated aloe gel enriched with aloins (bitter) to inhibit collagenase and metalloproteases activity, which can degrade collagen connective tissue when unchecked. This activity supports the use of aloe in the treatment of chronic ulcers, burns and wounds. Immune modulation Research on immune stimulation has indicated that acemannan, a polysaccharide within aloe, stimulated macrophage cytokine production and killer T cells (Zhang 1996). Chronic exposure to UV radiation causes sunburn, premature aging of the skin and genetic mutations leading to skin cancer. UV radiation causes systemic suppression of immune responses. Strickland (2001) showed that the gel prevented systemic suppression of T cell mediated immune response and the production of IL-10. The aloe polysaccharides are immunostimulants by interfering with the activation of suppressor mechanisms. Acemannan used for HIV-1+ patients showed a significant increase in the number of circulating monocytes and macrophages (McDaniels 1990a).
In a pilot study treating HIV infected people acemannan increased the number of white blood cell and improved symptoms (McDaniels 1990b). Gastrointestinal functions The aloe juice has been used as a tonic in a series of trials (Bland 1985) on human patients. It indicated a tonic effect on the intestinal tract with: a reduction in pH; a reduction in bowel transit time; intestinal bacterial flora benefited with a reduction in yeast; bowel putrefaction was reduced and protein digestion and absorption was improved. Yamamoto (1973) showed that a component of A. ferox suppresses ulcer growth and L-histidine decarboxylase in rats. Recently the gastropreventative of aloe was demonstrated by inhibiting gastric acid secretion, which makes it suitable for peptic ulcer treatment (Yusuf 2004). When juice is given orally to animals, mannans have been shown to lower cholesterol by inhibiting cholesterol absorption (Tizard 1986). In a small trial with monkeys it was found that aloe juice lowered total cholesterol by 61% with a proportionate rise in HDL (Dixit, 1983). Aloe juice has been used with success to lower blood sugar and triglyceride levels. Diabetic patients that failed to respond to other medication responded to aloe treatment (Reynolds, 1999).
It has been demonstrated that both the aloe exudate (bitter) and gel decreased blood glucose levels in mice. Similarly it has been found that both compounds have a protective effect against hepatotoxic liver injury (Can 2004). The cathartic and laxative action of aloe bitter is well established. Its primary effect is caused by its influence on the motility of the colon (inhibition of stationary and stimulation of propulsive contractions). This results in an accelerated intestinal passage and a reduction in liquid absorption increasing water content in the faeces (Blumenthal 1998). In addition to the purgative effect the anthraquinone (bitter) substances stimulate the flow of gastric juices thus improving digestion. Soeda (1964) found that fractions from A. ferox gave a prophylactic (prevents infection) effect. While in a subsequent study, Soeda (1966) found the aloe juice to have inhibitory action against some bacteria and fungi, particularly Pseudomonas aeroginosa and Proteus vulgaris.
Anti-cancer activity An early report by Soeda (1969) reported anti-tumour activity of A. ferox. Both plant fractions have been shown to inhibit tumour growth. Aloe-emodin has shown mutagenesis inhibition as well as the glycoproteins (lectins) and polysaccharides from the gel. Kuo (2002) has demonstrated that aloe-emodin induced apoptosis (cell disintegration) and acted as an effective anticancer effect in human liver cancer. Similarly, Pecere (2000) found that aloe-emodin did not inhibit fibroblast proliferation while selectively inhibiting human neuroectodermal tumour cells. A purified polysaccharide indicated anticarcinogenic effects by inhibiting the uptake of B[a]P and subsequently binding to cellular DNA. It also had no cytotoxic effect (destructive to cells) (Kim 1999). Strickland (2001) demonstrated the polysaccharides efficacy to prevent non-melanoma skin cancers by preventing T cell immune suppression. Anti-microbial Reynolds (1999) has reviewed the antimicrobial activity of aloe. Antibacterial: The aloe gel and bitter is bactericidal against: a variety of common wound infecting bacteria: Streptococcus pyogenes, Serratia marcescens, Klebsiella pneumonia, Staphylococcus aureus, E. coli, Mycobacterium tuberculosis, Pseudomonas auruginosa and Corynebacterium xerose. The gel is effective against: Streptococcus faecalis responsible for urinary infection. Ferro (2003) showed effective growth inhibition of Shigella flexneri and Streptococcus pyogenes responsible for gastroenteritis. Aloe-emodin in bitter has been shown to inhibit: growth of Helicobacter pylori, which is responsible for peptic ulcers (Wang 1998). Citrobacter, Enterobacter aerogenes, Serratia and Klebsiella that cause gastroenteritis. Proteus vulgaris an opportunistic pathogen of the urinary tract and Salmonella paratyphi causing fever. Antiviral: Aloe gel has been proven to be virucidal to: HIV-1+ patients showing increased numbers of white blood cells and improvement in symptoms (McDaniels 1990b). Herpes simplex infection with significant faster healing time and higher number of healed lesions compared to the control (Syed 1997). Aloe bitter was virucidal: by disrupting the coating of the herpes and influenza virus (Sydiskis 1991). Antifungal: Aloe gel is shown to be fungicidal to: Candida albicans responsible for yeast infections of the mucous membranes. Trichophyton spp. by A. ferox juice (Soeda 1966) responsible for infections such as athlete’s foot and candidiasis (thrush).
Skin The skin is composed of polypeptide chains that form aggregates of collagen fibrils, which influences the swelling and water uptake by the skin. The diffusion of water through the skin is limited and controlled by the stratum corneum (skin surface) that is in equilibrium with the atmosphere and underlying tissue. Since aloe is approximately 99% water it penetrates through the surface of the skin (stratum corneum) to the vascular dermal area thus hydrating the skin. Concurrently, the gel forms a cover to prevent the escape of moisture in the skin. Aloe gel increases the penetration of the skin by water hydration, occlusiveness (closes passage) and by increasing compound solubility. Subsequently, Davis (1991) has demonstrated that aloe gel enhanced the penetration of hydrocortisone and adds to its biological activity. Concomitantly, aloe gel increased oxygen supply as a result of increased blood flow (Davis 1989) and stimulates fibroblast activity and collagen proliferation (Thompson 1991) essential for skin tissue regeneration. Subsequently aloe gel it is used extensively in cosmetics. Aloe gel reduces photo aging by restoring the activity of epidermal cells reduced by UV exposure. The gel increase soluble collagen levels and biosynthesis possibly through macrophage stimulation (Lindblad 1994) In a large clinical trial Syed (1996) studied the effect of an Aloe cream on psoriasis vulgaris. They found that the aloe cream cured 83.3% of the patients compared to 6.6% of the placebo group with a concomitant clearing of the psoriatic plaques. There were no adverse drug reactions or side effects. A study by Vardy (1999) has demonstrated the effectiveness of an aloe lotion for treating seborrheic dermatitis (excessive excretion of sebaceous glands, dandruff) when applied on the skin twice a day. External use: Allergic reactions are rare and there is no reported toxicity.
Internal use: Aloe juice: Aloe juice appears safe and there is no reported toxicity. The mucilage in the aloe juice may interfere with the absorption of other oral medications taken concurrently Aloe bitter: The anthraquinones in the aloe bitters can cause severe diarrhoea and intestinal cramping when overdosed. Chronic internal use of anthraquinones can lead to potassium loss, dehydration and intestinal dependence on laxatives. The aloe bitters may reduce absorption of drugs due to decreased bowel transit time, may increase potassium loss in patients taking corticosteroids or thiazide diuretics, and may potentiate digitalis and other cardiac glycosides due to low potassium levels. Aloe bitters is not recommended for people with intestinal obstruction, intestinal inflammation (eg. Crohn’s disease, ulcerative colitis), appendicitis and abdominal pain of unknown origin. It is clinically proven that the use of anthranoid laxatives, even in the long term, does not cause cancer (Nusko 2000).
REFERENCES Blumenthal, m., busse, W.r., goldberg, a., hall, t. et al. 1998. German Commission E Monographs. Austin:American Botanical Council and Integrative Medicine Communications. BAUTISTA, R., SEGURA, D.& VAZQUEZ, B. 2004. In vitro antibradykinin activity of Aloe barbadensis gel. J. of Ethnopharmacology. In press. BARRANTES, E. & GUINEA, M. 2003. Inhibition of collagenase and matalloproteinases by aloins and aloe gel. Life Sciences. vol.72. p 843-850. BLAND, J. 1985. Effect of orally consumed Aloe vera juice on gastrointestinal function in normal humans. Preventive Medicine. vol.14. p 152-154. BRUCE, W.G.G. 1975. Medicinal properties in the aloe. Excelsa. no.5. p 57-68. CAN, A., AKEV, N., OZSOV, N., BOLKENT, S., ARDA, B.P., et al. 2004. Effect of Aloe vera leaf gel and pulp extract on the liver in type II diabetic rat models. Biol. Pharm. Bull. vol.27. no.5. p 694-698. CHOI, S.W., SON, B.W., SON, Y.S., PARK, Y.I., LEE, S.K. & CHUNG, M.H. 2001. The wound healing effect of a glycoprotein fraction isolated from aloe vera. British J. of Dermatology. vol.145. no.4. p 535-545. CLAYTON, L.T. (Ed.) 1993. Taber’s Cyclopedic Medical Dictionary. Philadelphia:F.A. Davis Company. DAVIS, R.D., SHAPIRO, E. & AGNEW, P.S. 1985. Topical effect of Aloe with ribonucleic acid and vitamin C on adjuvant arthritis. J. Am. Podiatric Med. Ass. vol.75. p 229-237. DAVIS, R.D., LEITNER, M.G., RUSSO, J.M. & BYRNE, M.E. 1989. Wound healing. Oral and topical activity of Aloe vera. J. Am. Podiatric Med. Ass. vol.79. no.11. p 559-562. DAVIS, R.D., PARKER, W.L., & MURDOCH, D.P. 1991. Aloe vera as a biological vehicle for hydrocortisone acetate. J. Am. Podiatric Med. Ass. vol.81. p 1-9. DAVIS, R.D., STEWART, G.J. & BREGMAN, P.J. 1992. Aloe vera and the inflamed synovial pouch model. J. Am. Podiatric Med. Ass. vol.82. no.3. p 140-148. DAVIS, R.H., DIDONATO, J.J., HARTMAN, G.M. & HAAS, R.C. 1994. Anti-inflammatory and wound healing activity of a growth substance in Aloe vera. J. Am. Podiatric Med. Ass. vol.84. no.2. p 77-81. DIXIT, V.P. & JOSHI, S. 1983. Effect of Aloe barbadensis and clofibrate on serum lipids in triton induced hyperlipidaemia in Presbytis monkeys. Indian J. of Medical Research. vol.78. p 417-421. FEMENIA, a., Sanchez, e.s., Simal, S, & Rosello, C. 1999. Compositional features of polysaccharides from Aloe vera (Aloe barbadensis Miler) plant tissue. Carbohydrate polymers. vol.39. p 109-117. FERRO, V.A., BRADBURY, F., CAMERON, P., SHAKIR, E., RAHMAN, S.R. & STIMSON, W.H. 2003. In Vitro susceptibilities of Shigella flexneri and Streptococcus pyogenes to inner gel of Aloe barbadensis Miller. Antimicrobial Agents and Chemotherapy. vol.47. no.3. p 1137-1139. GRINDLAY, D. & REYNOLDS, T. 1986. The Aloe vera phenomena: a review of the properties and modern uses of the leaf parenchyma gel. J. of Ethnopharmacology. vol.16. p 117-151. 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Sustained increase in collagen biosynthesis in acemannan impregnated PVA implants in the rat. Wound Repair and Regeneration. vol.2. p 84. MABUSELA, W.T., STEPHEN, A.M. & BOTHA, M.C. 1990. Carbohydrate polymers from Aloe ferox leaves. Phytochemistry. vol.29. no.11. p 3555-3558. MCDANIELS, H.,COMBS, H.R.M, CARPENTER, R., KEMP, M & MCNALLY, B. 1990a. An increase in circulating monocyte/macrophage (M/M) is induced by oral acemannan in HIV-1 patients. Am. J. Clinical Pathology. vol.94. p 516-517. MCDANIELS, H., CARPENTER, R., KEMP, M. KAHLON, J. & MCNALLY, B. 1990b. Extended survival and prognostic criteria for acemannan (ACE-M) treated HIV patients. Antiviral Research Suppl. vol.1. p 117. NUSKO, G., SCHNEIDER, B., SCHNEIDER, I., WITTEKIND, C. & HAHN, E.G. 2000. Anthranoid laxative use is not a risk factor for colorectal neoplasia: results of a prospective case control study. Gut. vol.46. no.5. p 651-655. PECERE, T., GAZZALO, V., MUCIGNAT, C., PAROLIN, C., et al. 2000. Aloe-emodin is a type of anticancer agent with selective activity against neuroectodermal tumors. Cancer Research. vol.60. p 2800-2804. REYNOLDS, T. & DWECK, A.C. 1999. Aloe vera leaf gel: a review update. J. of Ethnopharmacology. vol.68. p 3-37. SHELTON, R.M. 1991. Aloe vera: its chemical and therapeutic properties. International J. of Dermatology. vol.30. p 679-683. Soeda M, Fukiwara, M and Otomo, M. 1964. Studies on the effect of Cape aloe for irradiation leucopenia. Nippon Igaku Hoshasen Gakkai Zasshi. Dec. 24, p 1109-1112. Soeda, M., Otomo, M., Ome, M & Kawashima K. 1966. Studies on anti-bacterial and anti-fungal activities of Cape aloe. Japan J. Bacteriology. vol.21, no.10, p 609-614. SOEDA, M. 1969. Studies on the anti-tumor activity in Cape Aloe. J. of The Medical Society of Toho University. vol.16. p 365-369. STRICKLAND, F.M. 2001. Immune regulation by polysaccharides: implications for skin cancer. J. of Photchemistry and Photobiology. vol.63. p 132-140. SYDISKIS, R.J., OWEN, D.G., LOHR, J.L., ROSLER, K-H. A. & BLOMSTER, R.N. 1991. Inactivation of enveloped viruses by antraquinones extracted from plants. Antimicrobial Agents and Chemotherapy. vol.35. no.12. p 2463-2466. SYED, T.A., AHMAD, S.A., HOLT, A.H., AHMAD, S.H. & AFZAL, M. 1996. Management of psoriasis with Aloe vera extract in a hydrop cream: aplacebo-controlled, double blind study. Trop. Med. Int. Health. vol.1. no.4. p 505-509. SYED, T., AFZAL, M., ASHFOX, A., HOLT, A., ALI, A & AHMAD, S. 1997. Management of genital herpes in men with 0.5% Aloe vera extract in a hydrophilic cream: a placebo-controlled double blind study. J. of Dermatology Treatment. vol.8. p 99-102. THOMPSON, J.E. 1991. Topical use of aloe vera derived allantoin gel in otolaryngology. Nose and Throat J. vol.70. p119. TIZARD, I., CARPENTER, R.H., MCNALLY, B.H. & KEMP, M. 1989. The biological activity of mannans andrelated complex carbohydrates. Molecular Biotherapy. vol. 1. p 290-296. VAN WYK, B-E., VAN RHEEDE VAN OUDTSHOORN, M.C.B. & SMITH, G.F. 1995. Geographical variation in the major compounds of Aloe ferox leaf exudates. Planta Med. vol.61, p 250-253. VAN WYK, B-E. & SMITH, G. 2003. Guide to the Aloes of South Africa, 2nd ed. Pretoria:Briza. VARDY, A.D., COHEN, A.D. & TCHETOV, T. 1999. A double-blind, placebo-controlled trial of Aloe vera (A. barbadensis) emulsion in the treatment of seborrheic dermatitis. J. Dermatology Treatment. vol.10. no.1. p 7-11. VAZQUEZ, B., AVILA, G.,SEGURA, D. & ESCALANTE, B. 1996. Anti-inflammatory activity of extracts from Aloe vera gel. J. Ethnopharmacology. vol.55. p 69-75. VILJOEN, A. 1999. A chemotaxonomic study of phenolic leaf compounds in the genus Aloe. PhD dissertation. Rand Afrikaans University. WANG, H., CHUNG, J., HO, C., WU, L. & CHANG, S. 1998. Aloe-emodin effects arylamin N-acetyltransferase activity in the bacterium Helicobacter pylori. Planta Medica. vol.64. p 176-178. YAGI, A., HARADA, N., YAMADA, H., IWADARE, S. & NISHIOKA, I. Antibradykin active material in Aloe saponaria. J. of Pharmaceutical Sciences. vol.71. no.10. p 1172-1174. YEN, G-C., DUH, P-D & CHUANG, D-Y. 2000. Antioxidant activity ofanthraquinones and anthrone. Food Chemistry. vol.70. p 437-441. YAMAMOTO, I. 1973. Aloe ulcin, a new principle of Cape aloe and gastrointestinal function, especially experimental ulcer in rats. J. of The Medical Society of Toho University. vol.17. p 243-347. YUSUF, S., AGUNU, A. & DIANA, M. 2004. The effect of Aloe vera Berger (Liliacceae) on gastric acid secretion and acute gastric mucosal injury in rats. J. of Ethnopharmacology. In press. ZHANG, L. & TIZARD, I.R. 1996. Activation of a mouse macrophage cell line by acemannan: the major carbohydrate fraction from aloe vera gel. Immunopharmacology. vol.35. no.2. p 119-128.
Cold processing vs. hot processing: impact on the potency of aloe products
Comments about cold-processing methods as opposed to hot-processing methods of plant materials purport the impression that "hot processing destroys the biological potency of the plant". This notion does not consider temperature specifics or processing conditions. It simply associates a very broad term ("hot") to an undesirable effect and then entrusts the imagination to convey the intended marketing message.
This marketing technique is employed profitably in the aloe business, where indiscriminate statements are often made without scientific support to confirm them. Some websites and other advertising campaigns actively communicate the message that "any form of processing or heat applied to plant material is detrimental to the plant, leaving it ineffective for use". This is a very twisted truth. The true part of the message is that processing does indeed alter any plant material. However, the only way to get plant material into a bottle is to subject the material to some physical and/or chemical action, which is in fact the very definition of "processing". Also, the only way to consume 100% natural and fresh aloe would be to munch through an aloe leaf shortly after it has been harvested!
Life today compels humans to consume processed products. Most simply don't have the luxury, time or money to each plant their own indigenous gardens and live healthy lives of its fruits and leaves. However, the choice of being truly informed lies with the individual. Discriminating between real dangers, marketing messages, and the full truth is not a luxury, but a choice.
Scientifically, there are many factors that could potentially diminish the biological potency of an aloe during processing. For example, the extent of grinding, crushing, freezing, heating, pressurizing, and treatment with chemical additives all play pivotal roles in preserving or diminishing the aloe's beneficial properties.
A claim about any processing method should be evaluated in the light of all the physical and chemical handling procedures that a plant undergoes. For example, under room temperature conditions, an aloe may be grinded and crushed to a worthless pulp, and then further treated with harsh chemicals to affect a desired outcome. In such a case, the "cold-processing" temperature would not preserve the aloe's potency. In another example, aloe leaves may be left whole (no crushing and grinding) but incinerated at high temperatures to a valueless ash. Analysing the effects of the entire processing method is fundamental to evaluate whether processed aloe leaves are beneficial to the product that contains them. However, this report is concerned with the claim that "hot processing destroys the aloe's potency". Hence, for the purpose of this report, only the effects of heat applied to the aloe during processing, are described.
To appreciate the synergistic delivery of the aloe's beneficial properties, it is perhaps first important to review the critical components of the Aloe ferox plant. These are the components that afford the potency of the aloe for human consumption and/or topical application. An Aloe ferox leaf is composed of many nutrients including amino acids, minerals, vitamins, monosaccharides, polysaccharides, fibre, organic acids, and glycosides (bitter containing components). Together, these components function synergistically to impart the aloe's beneficial properties. The relationship between the different components is excellently portrayed by using a conductor-orchestra concept1. Accordingly, polysaccharides act as a conductor leading a symphony, which is composed of many orchestra members. The symphony portrays the beneficial properties; the orchestra members represent the nutrients.
The conductor guides and facilitates individual melodies into a harmonious masterpiece. Without the orchestra members, the conductor has no symphony. In the same way, individual melodies without a conductor will most likely produce a cacophonous sound. Similarly, research suggests that polysaccharides guide the individual beneficial properties of aloe components into a nourishing supplement. From this metaphor, it becomes clear that the maximum preservation of each and every component of the aloe leaf is important during manufacturing.
Advocators of cold-processing often claim that application of any heat destroys the beneficial properties of the aloe. The reliability of this statement must be evaluated by analysing the decomposition temperatures of the different beneficial components. The decomposition temperature of a substance is that temperature at which a substance undergoes chemical change due to heating. As a result, the particular substance degrades into other chemical compounds, and will not be able perform the same functions as before.
The decomposition temperatures of the all the amino acids in the aloe leaf have been analyzed and are generally between 200ºC and 300ºC. There are three exceptions namely Valine (decomposes at 315ºC) and Ethnolamine and Glutamine (both decompose around 170ºC). These decomposition temperatures imply that amino acids found in the aloe will not degrade below 170ºC. The analysis of decomposition temperatures also implies that when processed at around 300ºC, virtually all amino acids of the Aloe ferox leaf are destroyed. This means that a manufacturing procedure which boils an aloe leaf in water (@ 100ºC), would retain the full amino acid potency, while a procedure that process a leaf at temperatures of around 300ºC, would destroy the amino acid potency.
Decomposition temperatures of minerals and fibre are very high. If the yard stick of 100ºC is used as maximum temperature to treating aloe leaves, the potency minerals and fibre components will safely be preserved.
Analysis of decomposition temperatures of vitamins contained in Aloe ferox leaves show that they are not very sensitive to heat. However, some vitamins degrade very quickly when exposed to air. The handling procedures, and not the heat or the lack thereof, are therefore particularly important to retain the vitamin content of the Aloe ferox leaf.
The importance of the polysaccharides in Aloe ferox leaves became clear from the orchestra metaphor. The decomposition temperatures of polysaccharides are of particular importance since they are responsible for delivering the potency. The effects of different temperatures on the polysaccharides in aloe leaves have been well researched2,3. Considering the importance of the role of polysaccharides, it is not only important to know the maximal stability temperature but also understand the application period before degration would set in.
Research found that thermal treatment of aloe leaves at 70ºC for a period as long as 10 hours, had no significant effect on the polysaccharide quantity or quality. At lower and also higher temperatures, polysaccharides lost both quality and quantity after being subject to heat treatment for long periods. However, for a short thermal treatment period (30 minutes), the losses of polysaccharide quality and quantity were minimal, even at temperatures as high as 90ºC.
These findings regarding polysaccharide stability, together with an analysis of the decomposition temperatures of other aloe components, demonstrate that hot processing as such is not necessarily detrimental to the plant material. It is the specifics of the temperature and the period that the material is exposed to heat, that may destroy the potency of the aloe. It becomes clear that a statement claiming that "cold processing is the best while hot processing is detrimental to the beneficial properties of the aloe" is a marketing scheme aimed at promoting a certain product. The decomposition of the biological activity of aloe loe leaves depends on many factors, including the post-harvesting processing time, mechanical crushing and grinding, chemical and enzymatic treatment, and storage.
Based on scientific support, the full truth is that an aloe that is gently harvested, and timeously processed at temperatures below 90ºC, without mechanically or chemically damaging it during manufacturing, and then stored under minimal bacterial exposure, is much more potent and healthy than an aloe that is subject to mechanical, chemical, and enzymatic damage at room temperature.
References 1. Davis, R.H. Aloe vera - A Scientific Approach. Vantage Press Inc.: New York; pp 290 – 360; 1997. 2. Chang X.L.; Wang C.; Yongmei F.; Liu Z. Effects of heat treatments on the stabiolities of polysaccharides substances and barbaloin in gel juice from Aloe vera Miller. Journal of Food Engineering; 75; pp 245 – 251. 2006. 3. Antoni F.G.; Pablo S.; Susana S.; Carmen R. Effect of heat treatment and dehydration on bioactive polysaccharide acemannan and cell wall polymers from Aloe barbadensis Miller. Carbohydrate Polymers; 51; pp 379 – 405; 2003.