Aloe vera is known as the healing plant and the silent healer. This plant possesses several important properties, such as immunomodulation, wound healing, healing of heat-related damage and burn, and anti-inflammatory.
The exact mechanism of action of Aloe vera is not known. However, in vivo, Aloe vera gel and its phytoconstituents correct the immunosuppression caused by UV rays. Also, in vitro, several constituents of Aloe and its gel have shown antioxidant activity. Acemannan, which is of the main ingredients in Aloe gel, has immunostimulant properties.
The polysaccharides present in Aloe vera extract are absorbed orally and act in an unchanged form in the blood as immunomodulators and can induce immune responses, and modulate immune function, especially through activation of macrophages and production of cytokines.
Acemannan increases the activity of monocytes, macrophages and their cytotoxicity and stimulates Killer T-Cells. In 14 AIDS patients, daily intake of 800 mg acemannan resulted in objective increase in number of circulating monocytes and macrophages and improved clinical symptoms. The release of interleukin I, interleukin 6 TNF-α and TNF-δ from macrophages is dose-dependently induced. Acemannan alone, or as adjuvant to antivirals such as azidothymidine and acyclovir prevent multiplication of HIV and herpes virus. Aloe-emodin deactivates influenza virus, Varicella zoster and Pseudorabies virus. The anthraquinones isolated from Aloe, too, kill enveloped viruses.