Aloe barbadensis (Miller) or Aloe Vera  is a succulent plant renowned for its medicinal and cosmetic uses. This evergreen perennial is native to the Arabian Peninsula but widely cultivated around the world. Its thick, fleshy leaves contain a gel-like substance that is highly valued for its soothing and healing properties. Aloe vera is used extensively in skincare, health supplements, and traditional medicine.

Botanical Classification:

• Kingdom: Plantae
• Order: Asparagales
• Family: Asphodelaceae
• Genus: Aloe
• Species: Aloe barbadensis

Plant Characteristics:

• Growth Form: Aloe vera is a rosette-forming succulent with a basal rosette of thick, fleshy, lance-shaped leaves. It typically grows up to 60-90 cm (24-36 inches) in height and spreads outward.
• Leaves: The leaves are long, lance-shaped, and have a smooth, green to grey-green surface with serrated edges. They contain a clear, gel-like substance within their tissues.
• Flowers: Aloe vera produces tall flower spikes that can reach up to 90 cm (36 inches) in height. The flowers are tubular and can vary in color from yellow to orange or red. Flowering usually occurs in the winter or early spring.
• Fruit: The plant produces a capsule that contains numerous small seeds.

Chemical Composition and Structure:

• Aloe Vera Gel:The gel inside the leaves is composed of:
  • Polysaccharides: Such as acemannan, which is responsible for the plant's soothing and healing effects.
  • Vitamins: Including vitamins A, C, and E, which are known for their antioxidant properties.
  • Minerals: Such as calcium, magnesium, zinc, and potassium, which contribute to its nutritional profile.
  • Enzymes: Including amylase and lipase, which aid in the breakdown of sugars and fats.
  • Amino Acids: Aloe vera gel contains 20 of the 22 essential amino acids needed by the human body.

How to Cultivate It:

• Soil: Aloe vera prefers well-drained soil, ideally a sandy or loamy mix. It is important to avoid waterlogged conditions, which can lead to root rot.
• Climate: Aloe vera thrives in warm climates and is suitable for USDA hardiness zones 8-11. It requires plenty of sunlight and performs best in temperatures ranging from 15-30°C (59-86°F).
• Watering: The plant is drought-tolerant and should be watered sparingly. Allow the soil to dry out between waterings to prevent overwatering.
• Propagation: Aloe vera can be propagated from offsets or pups that grow around the base of the plant. These can be separated and replanted once they are large enough.

Uses and Benefits:

• Skincare: Aloe vera gel is widely used in skincare products for its moisturizing, soothing, and anti-inflammatory properties. It helps to alleviate sunburn, minor burns, and skin irritations.
• Haircare: Aloe vera is included in hair products to promote healthy scalp and hair. It helps to condition the hair, reduce dandruff, and soothe an itchy scalp.
• Health Supplements: Aloe vera juice is consumed for its potential digestive benefits and detoxifying properties. It is believed to aid in digestion and support overall gut health.
• Traditional Medicine: Aloe vera has been used in traditional medicine for centuries to treat a variety of conditions, including wounds, digestive issues, and inflammation.

Applications:

• Cosmetics and Personal Care: Aloe vera is a common ingredient in lotions, creams, gels, and shampoos due to its moisturizing and soothing properties.
• Pharmaceuticals: Used in topical formulations for burns, wounds, and skin conditions due to its healing effects.
• Food and Beverages: Aloe vera juice is used as a health drink and in various food products for its purported health benefits.

Environmental and Safety Considerations:

• Environmental Impact: Aloe vera is a sustainable crop that requires minimal water and can thrive in arid conditions. It has a low environmental footprint compared to more water-intensive crops.
• Safety: Aloe vera is generally safe for topical and internal use when used appropriately. However, some individuals may experience allergic reactions or skin irritation. It is advisable to perform a patch test before widespread application.

The most common aloes used in medicine and cosmetics are :

• Aloe barbadensis
• Aloe ferox
• Aloe greatheadii

Studies

The use of herbs is a well-established method for treating certain diseases, but herbs can trigger side effects and can interact with other herbs, supplements or medications. For these reasons, one should only proceed with caution when taking them with the assistance of a doctor (1). In any case, it is important to set quantities and frequency of intake that only a doctor can prescribe.

Latex and gels are made from the plant with a long history of topical and local therapy, as a treatment for burns, wounds, skin irritation and constipation, and in Ayurvedic medicine it is used against skin diseases, however ingestion has been associated with several physical ailments (2).

It abounds in anthraquinones, plant enzymes and useful tricyclic aromatic secondary metabolites, including aloe emodin and chrysophanol (3).

It contains antioxidant vitamins (A, C, E, B12), niacin, riboflavin and folic acid and, used as a laxative stimulant, anthelmintic. It also contains potassium, calcium, magnesium, copper, zinc, chromium, iron and magnesium lactate (4) as well as polysaccharides (glucomannans), amino acids, fatty acids (lupeol and campesterol), lipids, plant sterols, tannins and enzymes (amylase, catalase and peroxidase) used as herbal medicines.

Skin

Aloe vera improved epithelialisation and granulation tissue of burn wounds in patients with superficial second degree burns (5) and significantly increased skin elasticity index (6) and collagen levels (7).

Digestive system

Aloe has been used for the treatment of diseases affecting the digestive system and in particular has been closely associated with gastroprotection having demonstrated the potential to alleviate alcohol-induced acute gastric injury (8).

Diabetes

Aloe vera administration has been shown to restore blood glucose levels to normal with a concomitant increase in insulin levels, thereby exerting antidiabetic effects, improving insulin secretion, pancreatic β-cell function and restoring pancreatic islet mass (9).

Bones

The results of this study indicate that Aloe is an excellent source of antioxidant and anti-osteoporotic phytochemicals (10).

Teeth

Aloe vera may prove to be an effective mouthwash due to its ability to reduce dental plaque (11).

For more information:

Aloe vera studies

References_____________________________________________________________________

(1) Aloe - University of Maryland - Medical Center http://umm.edu/health/medical/altmed/herb/aloe

(2) Boudreau M, Beland F (2006) An evaluation of the biological and toxicological properties of Aloe barbadensis (miller), Aloe vera. J Environ Sci Heal C 24: 103–154

Abstract. Aloe barbadensis (Miller), Aloe vera, has a long history of use as a topical and oral therapeutic. The plant is the source of two products, gel and latex, which are obtained from its fleshy leaves. Aloe vera products contain multiple constituents with potential biological and toxicological activities, yet the active components elude definition. Ingestion of Aloe vera is associated with diarrhea, electrolyte imbalance, kidney dysfunction, and conventional drug interactions; episodes of contact dermatitis, erythema, and phototoxicity have been reported from topical applications. This review examines the botany, physical and chemical properties, and biological activities of the Aloe vera plant.

(3) Enhancement of Anti-Inflammatory Activity of Aloe vera Adventitious Root Extracts through the Alteration of Primary and Secondary Metabolites via Salicylic Acid Elicitation
Yun Sun Lee, Hyun Kyoung Ju, Yeon Jeong Kim, Tae-Gyu Lim, Md Romij Uddin, Yeon Bok Kim, Jin Hong Baek, Sung Won Kwon, Ki Won Lee, Hak Soo Seo, Sang Un Park, Tae-Jin Yang
PLoS One. 2013; 8(12): e82479. Published online 2013 Dec 16. doi: 10.1371/journal.pone.0082479

Abstract. Aloe vera (Asphodeloideae) is a medicinal plant in which useful secondary metabolites are plentiful. Among the representative secondary metabolites of Aloe vera are the anthraquinones including aloe emodin and chrysophanol, which are tricyclic aromatic quinones synthesized via a plant-specific type III polyketide biosynthesis pathway. However, it is not yet clear which cellular responses can induce the pathway, leading to production of tricyclic aromatic quinones. In this study, we examined the effect of endogenous elicitors on the type III polyketide biosynthesis pathway and identified the metabolic changes induced in elicitor-treated Aloe vera adventitious roots. Salicylic acid, methyl jasmonate, and ethephon were used to treat Aloe vera adventitious roots cultured on MS liquid media with 0.3 mg/L IBA for 35 days. Aloe emodin and chrysophanol were remarkably increased by the SA treatment, more than 10-11 and 5-13 fold as compared with untreated control, respectively. Ultra-performance liquid chromatography-electrospray ionization mass spectrometry analysis identified a total of 37 SA-induced compounds, including aloe emodin and chrysophanol, and 3 of the compounds were tentatively identified as tricyclic aromatic quinones. Transcript accumulation analysis of polyketide synthase genes and gas chromatography mass spectrometry showed that these secondary metabolic changes resulted from increased expression of octaketide synthase genes and decreases in malonyl-CoA, which is the precursor for the tricyclic aromatic quinone biosynthesis pathway. In addition, anti-inflammatory activity was enhanced in extracts of SA-treated adventitious roots. Our results suggest that SA has an important role in activation of the plant specific-type III polyketide biosynthetic pathway, and therefore that the efficacy of Aloe vera as medicinal agent can be improved through SA treatment.

(4) Shelton M. Aloe vera, its chemical and therapeutic properties. Int J Dermatol. 1991;30:679–683. doi: 10.1111/j.1365-4362.1991.tb02607.x

(5) Irani PS, Varaie S. Comparison of the Effect of Aloe Vera Gel and Nitrofurazone 2% on Epithelialization and Granulation Tissue Formation Regarding Superficial Second-Degree Burns. Iran J Med Sci. 2016 May;41(3 Suppl):S3. 

Abstract. Background: Therapeutic effects of various treatment options in burn wound healing have been one of the most controversial issues in wound care. Aloe Vera is an herbal medicine, which has wound healing effects on chronic wound. The present study was carried out to examine and compare the effect of Aloe Vera gel and nitrofurazone 2% on epithelialization and granulation tissue formation with respect to superficial second-degree burns....Conclusion: In conclusion, Aloe Vera gel enhanced epithelialization and granulation tissue of burn wounds in superficial second-degree burn patients better than nitrofurazone 2%. The mechanism of the remarkable efficacy of Aloe Vera gel in the epithelialization and granulation tissue of burn injuries may be explained by its hydrocolloid and moisturizing and anti-inflammatory effects.

(6) Tanaka M, Yamamoto Y, Misawa E, Nabeshima K, Saito M, Yamauchi K, Abe F, Furukawa F. Aloe sterol supplementation improves skin elasticity in Japanese men with sunlight-exposed skin: a 12-week double-blind, randomized controlled trial. Clin Cosmet Investig Dermatol. 2016 Nov 10;9:435-442. doi: 10.2147/CCID.S118947. Erratum in: Clin Cosmet Investig Dermatol. 2016 Dec 16;10 :1. 

Abstract. Background/objective: Recently, it was confirmed that the daily oral intake of plant sterols of Aloe vera gel (Aloe sterol) significantly increases the skin barrier function, moisture, and elasticity in photoprotected skin. This study aimed to investigate whether Aloe sterol intake affected skin conditions following sunlight exposure in Japanese men....Results: Depending on the time for the revelation of the sunlight, the b* value and melanin index increased and the skin moisture decreased. After taking an Aloe sterol tablet daily for 12 weeks, the skin elasticity index (R2, R5, and R7) levels were significantly higher than the baseline value. There were no differences between the groups in these skin elasticity values. In the subgroup analysis of subjects aged <46 years, the change in the R5 and R7 was significantly higher in the Aloe group than in the placebo group at 8 weeks (P=0.0412 and P=0.0410, respectively). There was a difference in the quantity of sun exposure between each subject, and an additional clinical study that standardizes the amount of ultraviolet rays is warranted. No Aloe sterol intake-dependent harmful phenomenon was observed during the intake period. Conclusion: Aloe sterol ingestion increased skin elasticity in the photodamaged skin of men aged <46 years.

(7) Tanaka M, Yamamoto Y, Misawa E, Nabeshima K, Saito M, Yamauchi K, Abe F, Furukawa F. Effects of Aloe Sterol Supplementation on Skin Elasticity, Hydration, and Collagen Score: A 12-Week Double-Blind, Randomized, Controlled Trial. Skin Pharmacol Physiol. 2016;29(6):309-317. doi: 10.1159/000454718.

(8) Park CH, Son HU, Yoo CY, Lee SH. Low molecular-weight gel fraction of Aloe vera exhibits gastroprotection by inducing matrix metalloproteinase-9 inhibitory activity in alcohol-induced acute gastric lesion tissues. Pharm Biol. 2017 Dec;55(1):2110-2115. doi: 10.1080/13880209.2017.1371770. 

Abstract. Context: Aloe has been used for the prevention and cure of various diseases and symptoms including burns, injuries, oedema and pain. Objective: This study determines the specific inhibitory activity of matrix metalloproteinase (MMP)-9 induced by the low molecular-weight gel fraction of Aloe vera (L.) Burm.f. (lgfAv) on alcohol-induced acute gastric lesions....Conclusions: The present findings suggest that lgfAv has the potential to alleviate alcohol-induced acute gastric lesions, which is mediated in part, mainly by the suppression of the mRNA expression of MMP-9.

(9) Noor A, Gunasekaran S, Vijayalakshmi MA. Improvement of Insulin Secretion and Pancreatic β-cell Function in Streptozotocin-induced Diabetic Rats Treated with Aloe vera Extract. Pharmacognosy Res. 2017 Dec;9(Suppl 1):S99-S104. doi: 10.4103/pr.pr_75_17.

Abstract. Background: Diabetes mellitus is a metabolic disorder characterized by chronic hyperglycemia. Plant extracts and their products are being used as an alternative system of medicine for the treatment of diabetes. Aloe vera has been traditionally used to treat several diseases and it exhibits antioxidant, anti-inflammatory, and wound-healing effects. Streptozotocin (STZ)-induced Wistar diabetic rats were used in this study to understand the potential protective effect of A. vera extract on the pancreatic islets. Objective: The aim of the present study was to evaluate the A. vera extract on improvement of insulin secretion and pancreatic β-cell function by morphometric analysis of pancreatic islets in STZ-induced diabetic Wistar rats....Conclusion: A. vera extract exerts antidiabetic effects by improving insulin secretion and pancreatic β-cell function by restoring pancreatic islet mass in STZ-induced diabetic Wistar rats.

(10) Sun YN, Li W, Lee SH, Jang HD, Ma JY, Kim YH. Antioxidant and anti-osteoporotic effects of anthraquinones and related constituents from the aqueous dissolved Aloe exudates. Nat Prod Res. 2017 Dec;31(23):2810-2813. doi: 10.1080/14786419.2017.1295238. 

Abstract. In this study, 25 known anthraquinones and related compounds were isolated from aqueous dissolved Aloe exudates. The antioxidant and anti-osteoporotic activities of the isolated compounds were then investigated. Compounds 8, 11, 20, and 23 showed good antioxidant activity based on peroxyl radical-scavenging and reducing capacity assays at a concentration of 10.0 μM. Additionally, compounds 7, 9, 15-16, 18, 21-22 and 24-25 showed potent peroxyl radical-scavenging activities with values ranging from 5.28 to 14.60 at 10.0 μM. Moreover, compounds 8, 11, 15, 20 and 22 exhibited significantly suppressed tartrate-resistant acid phosphatase (TRAP) activity in nuclear factor-κB ligand-activated osteoclastic RAW 264.7 cells, with values of 125.67, 118.54, 127.64, 125.82 and 124.98%, respectively. These results indicate that Aloe is an excellent source of antioxidant and anti-osteoporotic phytochemicals.

(11) Gupta RK, Gupta D, Bhaskar DJ, Yadav A, Obaid K, Mishra S. Preliminary antiplaque efficacy of aloe vera mouthwash on 4 day plaque re-growth model: randomized control trial. Ethiop J Health Sci. 2014 Apr;24(2):139-44. doi: 10.4314/ejhs.v24i2.6.

Abstract. Background: Due to increasing resistance to antibiotics and rising incidence of oral diseases, there is a need for alternative treatment modalities to combat oral diseases. The aim of the present study was to access the effect of Aloe vera mouthwash on the dental plaque in the experimental period of 4 days and to compare it with the bench mark control chlorhexidine and placebo (saline water)....Conclusion: The results of the present study indicated that Aloe vera may prove an effective mouthwash due to its ability in reducing dental plaque.