WORLD JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES

Priya

World Journal of Pharmacy and Pharmaceutical Sciences

SJIF Impact Factor 2.786

Volume 3, Issue 11, 209-218.

Review Article

ISSN 2278 – 4357

ALOE VERA - A MIRACLE PLANT WITH BIOLOGICAL ACTIONS Dr.Priya Senan.V *Post Graduate Department of Biotechnology, SAS SNDP Yogam College (affiliated to Mahatma Gandhi University, Kottayam), Konni, Pathanamthitta, Kerala, 689691, India.

Article Received on 26 August 2014, Revised on 17 September 2014, Accepted on 09 October 2014

ABSTRACT Aloe vera is the oldest and most applied medicinal plant worldwide. This miracle plant plant is also known as the „harmonious remedy‟ by the Chinese people, the „elixir of youth‟ by the Russians and the „herb of immortality‟ by the ancient Egyptians. It originated in North Africa

*Correspondence for

and can now be found almost anywhere which has a mild climate. For

Author

centuries, Aloe vera (Aloe barbadensis) has been used to treat a

Dr. Priya Senan. V

number of medical conditions such as asthma, mild fever, wounds,

Department of

burns, gastrointestinal disorders, diabetes, immune modulation, AIDS,

Biotechnology, SAS SNDP

cancer and various skin diseases. So, there is an urgent need to

Yogam College (affiliated to Mahatma Gandhi University, Kottayam),

investigate more and more on scientific basis of the therapeutic potential of the miracle plant and to popularize it for great interest.

Konni, Pathanamthitta, Kerala, 689691 India

Key words: Aloe vera, Therapeutic potential, Immunomodulation, Antioxidant.

INTRODUCTION Aloe vera is a perennial, drought resisting and succulent plant belonging to Liliacea family, of which there are about 360 species. It is a cactus -like plant that grows readily in hot, dry climates and currently, because of demand, is cultivated in large quantities

[1]

.The Egyptians

called Aloe the „Plant of Immortality‟ because it can live and even bloom without soil. The name aloe, is derived from the Arabic “alloeh” or Hebrew “halal” meaning bitter shiny substance [2]. It is indigenous to Africa and Mediterranean countries

[3]

. Aloe vera has number

of uses and mainly they are used as food preservative and medicine. Commercially aloe can be found in pills, sprays, ointments, lotions, liquids, drinks, jellies and creams

[4]

. Numerous

aloe species around the world are used for conditions ranging from dermatitis to cancer [5]

.Various studies have revealed that Aloe vera leaf possesses many pharmaceutical activities

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including antimicrobial, anticancer, antioxidant, antidiabetic, antiulcer, hepatoprotective, immunomodulatory and many more activities [6-10 ] . HISTORY Aloe vera has been used for medicinal purposes in several cultures for millennia: Greece, Egypt, India, Mexico, Japan and China beauty regimen and medicines

[12]

[11]

. Cleopatra was said to include aloe cream in her

. The medicinal use of aloe was already mentioned more

than 4000 years ago in collection of Sumerian clay tablets dated 2100 BC. Aloe was also mentioned as a laxative in the Egyptian Papyrus Ebers from 1552 BC. Aloe had a very long historical use as a strong laxative treatment for chronic constipation; it is still listed as a laxative in many pharmacopoeias. PLANT DESCRIPTION The botanical name of Aloe vera is Aloe barbadensis Miller. It belongs to Liliacea family and is shrubby, perennial, xerophytic, succulent, pea green colour plant. The aloe plant has long, triangular, fleshy leaves that have spikes along the edges

[13]

. Each leaf is composed of three

layers, an inner clear gel that contains 99% water and rest is made up of glucomannans, aminoacids, lipids, sterols and vitamins. The middle layer of latex which is the bitter yellow sap and contains anthrquinones and glycosides. The outer thick layer of 15-20 cells called as rind which has protective function and synthesizes carbohydrates and proteins; this is the part that yields laxative anthraquinones [14]. ACTIVE COMPONENTS WITH ITS PROPERTIES Aloe contains 75 potentially active constituents: Vitamins, enzymes, minerals, sugar, lignin, saponins, salicylic acids and aminoacids [15-23]. 1.Anthraquinones/anthrones: It provides 12 anthraquinones, which are phenolic compounds traditionally known as laxatives. Aloin and emodine act as analgesics, antibacterials and antivirals. 2.Hormones: Auxins and gibberellins that help in wound healing and have anti-inflammatory action. 3.Vitamins: It contains vitamin A, C and E which are antioxidants. It also contains vitamin B12, choline and folic acid. Antioxidants neutralizes free radicals.

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4.Aminoacids: It provides 20 of the 22 human required amino acids and 7 of the 8 essential amino acids. It also contains salicylic acid that possesses anti-inflammatory and antibacterial properties. 5.Carbohydrates: It provides monosacchrides and polysaccharides. These are derived from the mucilage layer of the plant and are known as mucopolysaccharides (eg. mannan, acetylated mannan, acetylated glucomannan, glucogalactomannan, galactan, arabinogalactan etc.). A glycoprotein with antiallergic properties called alprogen and a novel antiinflammatory compound, C-glucosyl chromone has been isolated from Aloe vera gel [24-25] . 6.Enzymes: Alkaline phosphatase, amylase, bradykinase, carboxypeptidase, catalase, cyclooxidase, cylooxygenase, lipase, oxidase, carboxylase, superoxidase dismutase etc are present. Bradykinase helps to reduce excessive inflammation when applied to the skin topically, while others help in the breakdown of sugars and fats. 7.Inorganic compounds: The minerals like calcium, chromium, copper, selenium, magnesium, manganese, potassium, sodium and zinc are present. They are essential for the proper functioning of various enzyme systems in different metabolic pathways and few are antioxidants. 8.Fatty acids: It provides 4 plant steroids; cholesterol, campesterol, B sisosterol and lupeol. All these have anti-inflammatory action and lupeol also possesses antiseptic and analgesic properties. BIOLOGICAL AND PHARMACOLOGICAL ACTIONS OF ALOE VERA GEL Healing properties The gel Aloe vera was used for healing wounds and burns. It is used to relieve thermal burn, sun burn and promote wound healing

[26]

. The gel stimulates cell growth and enhances the

restoration of damaged skin. Aloe vera contains a majority of the necessary amino acids and vitamins that our skin needs to heal. The Aloe vera gel itself forms a glue like substance on skin which acts as a natural „band aid‟, sealing in the nutrients and allowing them to begin working immediately and keeping out any bacteria or agents that could cause healing to slow or cease completely. Reports have shown that the tannic acid and polysaccharides are effective components for wound healing

[27-28]

. Glucomannan, a mannose- rich

polysaccharide and gibberellins, a growth hormone interacts with growth factor receptors on the fibroblast, thereby stimulating its activity and proliferation, which in turn significantly increases collagen synthesis after topical and oral Aloe vera

[29]

. Aloe gel not only increased

collagen content of the wound but also changed collagen composition and increase the degree

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of collagen cross linking. Due to this it accelerated wound contraction and increased the breaking strength of resulting scar tissue

[30]

. An increased synthesis of hyaluric acid and

dermatan sulfate in the granulation tissue of a healing wound following oral or topical treatment has been reported [31]. Moisturising effect The gel moisturises the skin because it has a water holding capacity. Mucopolysaccharides help in binding moisture in to the skin. Aloe stimulates fibroblast which produces the collagen and elastin fibers making the skin more elastic and wrinkled. The amino acids present in the gel also soften hardened skin cells and zinc act as an astringent to tighten pores. It also has antiacne effect [32]. Antioxidant effects It has been reported by several authors that different fractions of Aloe vera gel as well as unfractionated whole gel have antioxidant effects. Glutathione peroxidase activity, superoxidase dismutase enzymes and a phenolic antioxidants were found to be present in Aloe vera gel, which may be responsible for these antioxidant effects. The cell free techniques used in this study assessed the scavenging of both superoxides and peroxyl radicals. The Aloe vera gel in a concentration of 1 in 50 also inhibited prostaglandin E2 production from inflamed colorectal biopsies, but had no effect on thromboxane B2 release [33].

Antimicrobial activities Antibacterial, antiviral

[34]

and antifungal activity of Aloe vera gel extract has been reported.

Aloe vera contains several antiseptic agents like lupeol, salicylic acid, urea nitrogen, cinnamonic acid, phenols and sulfur. Anthraquinones isolated from the exudate of Aloe vera have shown wide antimicrobial activity. Many anthraquinones have shown antiviral effects on enveloped viruses

[35].

They all have inhibitory action on fungi, bacteria and viruses.

Acemannan acts alone and synergistically with azidothymidine (AZT) and cyclovir to block reproduction of Herpes and AIDS Virus. A number of reports are available on the microbial activity of the hexane, ethanolic, acetone, petroleum ether, ethyl acetate extracts of Aloe vera gel and leaves [36-37]. Immune Modulation: Aloe gel helps to stimulate the body‟s immune system

[38].

Aloe

extracts increased phagocytosis in asthamatic adults [39]. Alprogen inhibit calcium influx into

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mast cells, thereby inhibiting the antigen antibody mediated release of histamine and leukotriene from mast cells

[40]

. In a study on mice that had previously been implanted with

murine sarcoma cells, acemannan stimulates the synthesis and release of interleukin-1 (IL-1) and tumour necrosis factor from macrophages in mice, which in turn initiated an immune attack that resulted in necrosis and regression of the cancerous cells. Several low molecular weight compounds are also capable of inhibiting the release of reactive oxygen free radicals from activated human neutrophils

[41]

.

Laxative effect Anthraquinones present in latex are a potent laxative. These water soluble glycosides are split by intestinal bacteria into aglycones which effect the laxative action. It increases intestinal water content, stimulates mucus secretion and increases intestinal peristalsis

[42]

. Aloe

emodin, a degradation product of B glycosides in the colon is the laxative metabolite. Gastro protective properties Aloe vera juice protects the mucus membrane of the stomach especially when irritated or damaged. Aloe vera juice is considered helpful for relieving many types of gastrointestinal irritation. It has been claimed that Aloe vera gel has the ability to cure gastric ulcers or protect against its formation in both animals and humans. The antiulcer activity of Aloe vera has been attributed to several possible mechanisms including its anti-inflammatory properties, healing effects, mucus stimulatory effects and regulation of gastric secretion

[43]

. It was

suggested that the Aloe vera extract possess cytoprotection activity at this low concentration, therefore protection against mucosal injury by means of a mechanism different from gastric acid inhibition and neutralization. Several hypothesis have been given for the mechanism of cytoprotection, namely increased mucus synthesis, increased mucosal blood flow and increased phospholipid content of the mucosal coating [44] . Antitumour/ anticancer activity The actions may be due to direct or indirect effects. Indirect effect is due to stimulation of the immune and direct effect is due to anthraquinones. Aloe vera stimulates the immune system that in turn protects the body against tumour related disorders. Two fractions from aloes that are claimed to have anticancer effects include glycoproteins (lectins) and polysaccharides [45] . The anti-tumour activity of polysaccharides isolated from aloe-vera and specifically acemannan has been investigated in many in vitro models as well as in different animal species. Different studies indicated antitumour activity for Aloe vera in terms of reduced

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tumour burden, tumour shrinkage, tumour necrosis and prolonged survival rates. One mechanism of acion that was proposed for these anticancer effects of aloe polysaccharides is stimulation of the immune response

[46]

apoptosis in cervical cancer cell lines

[47]

. It has been reported that the aloe emodin induces .

Anti-inflammatory activity: Aloe vera inhibits the cyclooxygenase pathway and reduces prostaglandin E2 production from arachidonic acid. Recently, the novel anti-inflammatory compound called C-glucosyl chrome was isolated from gel extracts [48]. Antiseptic effect: Aloe vera contains six antiseptic agents- Lupeol, salicylic acid, urea nitrogen, cinnamonic acid, phenols and sulfur. They all have inhibitory action on fungi, bacteria and viruses [49]. Antidiabetic effect Several preclinical and clinical trials showed a blood glucose lowering effect for Aloe vera gel preparations in different forms. Reports have shown that the mechanism of action Aloe vera extracts to reduce blood glucose levels in streptozotocin induced diabetic rats is by enhancing glucose metabolism. It was further proposed that the glucose lowering effect could be explained by an antioxidant mechanism because it attenuated oxidative damage in the brains of streptozotocin induced diabetic rats [50]. Intestinal drug absorption enhancement Only limited information is currently available on the drug absorption enhancement activities of A.vera gel, but if it proves to be safe and effective absorption enhancer in vivo, it could be used in novel dosage forms for the oral delivery of poorly absorbable drugs that are administered by means of injections. In a recent in vitro study it was shown that both A.vera gel and whole leaf extract could decrease the trans epithelial electrical resistance of intest inal epithelial cell monolayers (Caco-2), thereby indicating opening of the tight junctions between adjacent epithelial cells. The Aloe vera and whole leaf extract were also able to significantly increase the transport of the macromolecular peptide drug insulin, across the Caco-2 cell monolayers [51]. CONCLUSION The pharmacological attributes of Aloe vera have been revalidated in modern sciences through various in vivo and in vitro studies. Aloe vera has a long history as a medicinal plant

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with diverse therapeutic applications. Even though Aloe vera is a promising herb with its clinical applications in medicine, in future controlled studies are required to prove the effectiveness of Aloe vera under the various conditions. ACKNOWLEDGEMENT Thanks are to various research journals for their research findings for successful completion of this technical task. The author is grateful to the Principal, SAS SNDP Yogam College, Konni, Pathanmthitta, Kerala for the facilities provided for the literature survey. REFERENCES 1. Renisheya Joy Jeba MT, Johnson M, Nancy Beaulah S, Laju RS, Anu priya G, Renola Joy Jeba Ethal T. Antibacterial and antifungal activity of Aloe vera gel extract. Int J of Biomed and Adv Res, 2012; 03(3): 184-187. 2. Karkala M, Bhushan B. Aloe vera: A wonder plant its history, cultivation and medicinal uses. J Pharmacogn and Phytochem, 2014; 2(5): 85-88. 3. Rajeswari R, Umadevi M, Sharmila RC, Pushpa R, Selvavenkadesh S, Sampath Kumar KP, Debjit B. Aloe vera; the miracle plant its medicinal and traditional uses in India. J Pharmacogn and Phytochem. 2012; 1(4):118-125. 4. Hosseni N, Fakhraee R. Medical uses of Aloe vera. 5. Kathi JK, Victoria C. The long wood herbal task force and the centre for holistic pediatric education and research. Aloe vera, 1999; 1-24. 6. Bashir A, Saeed B, Talat YM, Jehan N. Comparative study of antimicrobial activities of Aloe vera extracts and antibiotics against isolates from skin infections. Afr J Biotech, 2011;10: 3835-3840. 7. Naveena, Bharath BK, Selva S. Antitumour activity of Aloe vera against Ehrlich Ascites Carcinomam (EAC) in Swiss Albino mice. International Journal of Pharma and Biosciences.2011; 2:200-409. 8. Miladi S, Damak M. In vitro antioxidant activities of Aloe vera leaf skin extracts. J Soc Chim Tunisie, 2008; 10: 101-109. 9. Jones K. Dietary Aloe vera supplementation and glycemic control in diabetes. B5 srl Nutraco, 2007; 6-9. 10. Borra SK, Lagisetty RK, Mallela GR. Anti-ulcer effect of aloe vera in non steroidal antiinflammatory drug induced peptic ulcers in Rats. Afr J of Pharma and Pharmacol, 2011; 5(16):1867-1872.

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11. Amar S, Resham Vasani, Saple DG. Aloe vera: A short review. Ind J Dermatol, 2008; 53(4):163-166. 12. Haller J. A drug for all seasons: medical and pharmacological history of aloe Bull NY Acad Sci.1990; 66. 13. Sharrif MM, Sandeep KV. Aloe vera their chemical composition and applications: A review. Int J of Biol and Med Res. 2011; 2(1): 466-471. 14. Schulz V, Hansel R, Tyler VE. Rational phytotherapy: A physicians guide to Herbal medicine. Berlin: Springer, 1997; 306. 15. Atherton P. Aloe vera revisited. Br J Phytother, 1998;4:76-83. 16. Shelton M. Aloe vera, its chemical and therapeutic properties. Int J Dermatol.1991; 30:679-683. 17. Atherton P. The essential Aloe Vera: the actions and the evidence. 2 nd ed 1997. 18. Ni Y, Tizard, IR. Analytical Methodology: the gel- analysis of aloe pulp and its derivatives. In aloes The Genius aloe- Reynolds, T., Ed.; CRC press: Bocaraton. 2004-pp 111-126. 19. Dagne E, Bisrat D, Viljoen A, VanWyk, BE. Chemistry of Aloes species. Curr. Org.Chem, 2000-4:1055-1078. 20. Femenia A, Sanchez ES, Simal S, Rosello C. Compositional features of polysaccharides from aloe vera (Aloe barbadensis Miller) plant tissues. Carbohydr. Polym, 1999-39:109117. 21. 21.Choi S, Chung, MH. A review on the relationship between Aloe vera components and their biologic effects. Semin. Integr.Med, 2003;1:53-62. 22. Surjushe A, Vasani R, Saple DG. Aloe vera: A short review. Indian J Deramatol, 2008; 53:163-166 23. Hamman JH. Composition and application of aloe vera leaf gel. Molecules, 2008; 13:1599-1616. 24. Ro JY, Lee B, Kim JY, Chung Y, Chung MH. Inhibitory mechanism of aloe single component (Alprogen) on mediator release in guinea pig lung mast cells activated with specific antigen-antibody reactions. J Pharmacol Exp Ther, 2000;292:114-21. 25. Hutter JA, Salmon M, Stavinoha WB, Satsangi N, Williams RF, Streeper RT. Anti– inflammatory C- glucosyl chromone from Aloe barbadensis. J Nat Prod, 1996;59:541-3. 26. Foster S. Aloe vera, The succulent with skin soothing cell protecting properties. Herbs for Health magazine, 1999. 27. Freytag A. Suggested role of tarumatic acid in aloe wound healing. Pharmiz, 1954;9:705

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28. Kameyama S, 1979.Wound healing compostion from Aloe arborescens extracts. Jap. Patent, 785-6995. 29. Chithra R, Sajithal GB, Chandrakasan G. Influence of aloe vera on collagen characteristics in healing dermal wounds in rats. Mol Cell Biochem, 1998;181:71-6. 30. Heggers J, Kucukcelebi A, Listengarten D, Stabenau J, Ko F, Broemeling LD. Beneficial effect of aloe on wound healing in an excisional wound model. J Althern Complement Med, 1996; 2:271-277. 31. Chitra P, Sajithal G, Chandrakasan G. Influence of Aloe on the Glycosamino glycans in the matrix of healing dermal wounds in rats. J Ethanopharmacol, 1998; 59: 179-186. 32. West DP, Zhu YF. Evaluation of Aloe vera gel gloves in the treatment of dry skin associated with occupational exposure. Am J Infect Control, 2003; 31: 40-42. 33. Langmead L, Makins RJ, Ramptons DS. Anti-inflammmatory effects of aloe vera gel in human colorectal mucosa in vitro. Aliment. Pharmacol. Ther, 2004; 19: 521-527. 34. Kahlon J, Kemp MCX, Yawei N, Carpenter RH, McAnalley HR, Shannon WM. In evaluation of the synergestic

antiviral effects of acemannan in combination with

azidothymidine and acyclovir. Molecular Biotherapy,1991; 3: 214-223. 35. Alves DS, Perez Fons L, Estepa A, Micol V. Membrane related effects underlying the biological activity of the anthrax quinines emodin and barbaloin.Biochem. Pharmacol, 2004; 68: 549-561. 36. Agarry OO, Olaleye MT, Bello-Michael CO. Comparative antimicrobial activities of aloe vera gel and leaf. Afr J of Biotech, 2005;4(12): 1413-1414. 37. Arunkumar S, Muthuselvam M. Analysis of phytochemical constituents and antimicrobial activities of Aloe vera L. against clinical pathogens. W J of Agri Sci. 2009; 5(5): 572576. 38. Davis HR. Aloe vera: A Scietific Approach Published by Vantage Press, New York, USA. 39. Shida T. Effect of aloe extract on peripheral phagocytosis in adult bronchial asthma. Planta Medica, 1985; 51:273-275. 40. Hart LA, Nibbering PH, Van Den Barselaar MT, Van Dijik H, Labdei. 41. Effects of low molecular weight constituents from Aloe vera gel on oxidative metabolism and cytotoxic and bactericidal activities of human neutrophils. Int J Immunopharmacol, 1990; 12: 427-434. 42. Ishii Y, tanizawa H, Takino Y. Studies of Aloe V. Mechanism of Cathartic effect. Biol Pharm Bull, 1994;17:651-653.

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43. Suvitayavat W, Sumrongkit C, ThirawarapanSS, Bunyapraphatsara N. Effects of aloe preparation on the histamine induced gastric secreation in rats. J Ethanopharmacol, 2004; 90:239-247. 44. Yusuf S, Agunu A, diana M. The effects of Aloe Vera A. berger (Liliaceae) on gastric acid secretion and acute gastric mucosal injury in rats. J Ehanopharmacol, 2004:93,3337. 45. Reynolds T, Dweck AC. Aloe vera leaf gel:

review update. J. Ethanopharmacol,

1999;68;33-37. 46. Steenkamp V, Stewart MJ. Medicinal applications and toxicological activities of Aloe products. Pharm.Biol, 2007,45;411-420. 47. Srinivas,G., Anto, R.J., Srinivas, P., Vidyalekshmi, S., Senan,V.P,

Karunagaran, D.

Emodin induces apoptosis of human cervical cancer cells through poly (ADP-ribose) polymerase cleavage and activation of caspase-9. Eur J Pharmacol. 2003; 473: 117-125. 48. Hutter JA, Salmon M, Stavinoha WB, Satsangi N, Williams RF, Streeper RT. Anti– inflammatory C- glucosyl chromone from Aloe barbadensis. J Nat Prod, 1996;59:541-3. 49. Zawahry ME, Hegazy MR, Helal M. Use of aloe in treating leg ulcers and dermatoses. Int J dermatol, 1973; 12:68-73. 50. Boudreu MD, Beland FA. An evaluation of the biological and toxicological properties of Aloe barbadensis (Miller), aloe vera. J Environ. Sci. Health C, 2006; 24:103-154. 51. Hamman JH, Viljoen AM. Use of Aloe vera for increasing the bioavailability of poorly absorbable drugs. 2008. SA patent application 2008/01542.

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