Aloe vera is a popular medicinal plant that people have used for thousands of years. The cosmetic, pharmaceutical, and food industries use aloe vera extensively, and the plant has an estimated annual market value of $13 billion1 globally. In the earlier issue, we have discussed on origin, chemical properties, and covered the major functions of aloe vera from the ancient times: skin healing and antidiabetic, in the detailed aspects of mechanism of action and clinical uses. Here in this article, we will dive into more of aloe vera’s health benefits in the modern days.
Gastroesophageal reflux disease (GERD) is a digestive disorder whereby the stomach acid flow back up into the mouth, that often results in heartburn. It usually feels like a burning chest pain that starts behind the breastbone and moves upward to the neck and throat. Aloe vera taken orally for 4 weeks lowered the occurence of symptoms of GERD including heartburn, food regurgitation, dysphagia, flatulence, belching, nausea, and acid regurgitation without causing adverse effects2.
Constipation is a condition in which one may have fewer than three bowel movements a week; occurs when bowel movements become less frequent and stools become difficult to pass. Anthraquinones present in aloe latex are a potent laxative3. It increases intestinal water content, stimulates mucus secretion and increases intestinal peristalsis. Treatment with aloe vera leaf extract for 7 days improved intestinal motility, increased fecal volume, and normalized body weight4.
The anticancer property of aloe vera extract in particular the therapeutic aloe emodin, is studied extensively in slowing down the growth of breast and cervical cancers. Aloe vera extracts reduced cell viability of cancer cell lines (human breast MCF-7 and cervical HeLa) through apoptosis cell death induction and modulation of effector genes expression5. Another recent study showed that Aloe vera extract and training (swimming) combined exerted a protective anticancer effect in breast cancer by inhibiting the COX pathway (COX-2 reduction levels) and prostaglandin E2 production6.
Acemannan, a β-(1–4)-acetylated polymannose extracted from aloe vera gel, has been suggested as biomaterial for bone regeneration7. Histologically, the acemannan-treated groups have increased bone surface, bone volume, and denser bone mass7.
Most of the studies focus on evaluation of the antibacterial activity of aloe vera and its main constituents on the most common bacteria, Staphlococcus aureus and Pseudomonas aeruginosa. Aloe vera aqueous extract reduced growth and biofilm formation against methicillin resistant Staphylococcus aureus8. One of the compounds attributed to antibacterial activity against Staphylococcus aureus is aloe-emodin which acts by inhibiting biofilm development and extracellular protein production9. Aloe vera extracts have shown to inhibit the growth and biofilm production of multidrug-resistant Pseudomonas aeruginosa isolated from burned patients10.
Antiviral activity of aloe vera has been researched for H1N1 subtype influenza virus. Aloe polysaccharides is demonstrated to reduce H1N1 subtype influenza virus replication and viral adsorption period by interacting with influenza virus particles, which in turn is evident with improved clinical functions and lung damage11.
Aloe vera has been traditionally used to treat skin injuries (burns, cuts, insect bites, and eczemas) owing to its skin healing properties as discussed earlier. Research on this medicinal herb that can be found at our gardens has been directed at authenticating traditional uses and deepening the mechanism of action, recognising the compounds responsible for these activities. Among the major active compounds, research in the last six years focused on aloe-emodin, aloin, aloesin, amodin, and acemannan12. Scientific progress has made it necessary to keep up-to-date in the research of old materials with new insights.
- Grace OM, Buerki S, Symonds MRE, Forest F, van Wyk AE, Smith GF, Klopper RR, Bjora CS, Neale S, Demissew S, Simmonds MSJ, Ronsted N. Evolutionary history and leaf succulence as explanations for medicinal use in aloes and the global popularity of Aloe vera. BMC Evol Biol. 2015; 15: 29. doi: 10.1186/s12862-015-0291-7.
- Panahi Y., Khedmat H., Valizadegan G., Mohtashami R., Sahebkar A. Efficacy and safety of Aloe vera syrup for the treatment of gastroesophageal reflux disease: A pilot randomized positive-controlled trial. J. Tradit. Chin. Med. 2015; 35:632–636. doi: 10.1016/S0254-6272(15)30151-5.
- Ishii Y, Tanizawa H, Takino Y. Studies of aloe. V: Mechanism of cathartic effect. Biol Pharm Bull. 1994;17:651–3.
- Ashafa TO, Sunmonu T, Abass AA, Ogbe A. Laxative potential of the ethanolic leaf extract of Aloe vera (L.) Burm. f. in Wistar rats with loperamide-induced constipation. August 2011Journal of Natural Pharmaceuticals 2(3). DOI:10.4103/2229-5119.86268.
- Hussain A., Sharma C., Saniyah K., Kruti S., Shafiul H. Aloe vera inhibits proliferation of human breast and cervical cancer cells and acts synergistically with cisplatin. Asian Pac. J. Cancer Prev. 2015; 16:2939–2946. doi: 10.7314/APJCP.2015.16.7.2939.
- Shirali S., Barari A., Hosseini S.A., Khodadi E. Effects of six weeks endurance training and Aloe vera supplementation on COX-2 and VEGF levels in mice with breast cancer. Asian Pac. J. Cancer Prev. 2017; 18:31–36.
- Godoy DJD, Chokboribal J, Pauwels R, Banlunara W, Sangvanich P, Jaroenporn S, Thunyakitpisal P. Acemannan increased bone surface, bone volume, and bone density in a calvarial defect model in skeletally-mature rats. Journal of Dental Sciences Volume 13, Issue 4, December 2018, Pages 334-341.
- Saddiq A.A., Al-Ghamdi H. Aloe vera extract: A novel antimicrobial and antibiofilm against methicillin resistant Staphylococcus aureus strains. Pak. J. Pharm. Sci. 2018; 31:2123–2130.
- Xiang H., Cao F., Ming D., Zheng Y., Dong X., Zhong X., Wang L. Aloe-emodin inhibits Staphylococcus aureus biofilms and extracellular protein production at the initial adhesion stage of biofilm development. Appl. Microbiol. Biotechnol. 2017; 101:6671–6681. doi: 10.1007/s00253-017-8403-5.
- Goudarzi M., Fazeli M., Azad M., Seyedjavadi S.S., Mousavi R. Aloe vera gel: Effective therapeutic agent against multidrug-resistant Pseudomonas aeruginosa isolates recovered from burn wound infections. Chemother. Res. Pract. 2015; 2015 doi: 10.1155/2015/639806.
- Sun Z., Yu C., Wang W., Yu G., Zhang T., Zhang L., Zhang J., Wei K. Aloe Polysaccharides Inhibit Influenza A Virus Infection-A Promising Natural Anti-flu. Drug. Front. Microbiol. 2018; 9:2338. doi: 10.3389/fmicb.2018.02338.
- Sanchez M, Gonzales-Burgos E, Iglesias I, Gomez-Serranilos MP. Pharmacological Update Properties of Aloe Vera and its Major Active Constituents. Molecules. 2020 Mar; 25(6): 1324. doi: 10.3390/molecules25061324.