Aloe Vera & Gibberellin, Anti-Inflammatory Activity In Diabetes
Davis RH; Maro NP
J Am Podiatr Med Assoc 79(1):24-6 1989 Jan

Aloe vera inhibits inflammation and adjuvant-induced arthritis. The authors’ laboratory has shown that A. vera improves wound healing, which suggests that it does not act like an adrenal steroid. Diabetic animals were used in this study because of their poor wound healing and anti-inflammatory capabilities. The anti-inflammatory activity of A. vera and gibberellin was measured in streptozotocin-induced diabetic mice by measuring the inhibition of polymorphonuclear leukocyte infiltration into a site of gelatin-induced inflammation over a dose range of 2 to 100 mg/kg. Both Aloe and gibberellin similarly inhibited inflammation in a dose-response manner. These data tend to suggest that gibberellin or a gibberellin-like substance is an active anti-inflammatory component in A. vera.

Anti-Inflammatory Activity Of Extracts From Aloe Vera Gel
Vázquez B; Avila G; Segura D; Escalante B
Laboratory Of Pharmacology, Escuela Nacional de Estudios Profesionales Iztacala (E.N.E.P-I), Universidad Nacional Autónoma de México
J Ethnopharmacol 55(1):69-75 1996 Dec

We studied the effects of aqueous, chloroform, and ethanol extracts of Aloe vera gel on carrageenan-induced edema in the rat paw, and neutrophil migration into the peritoneal cavity stimulated by carrageenan. We also studied the capacity of the aqueous extract to inhibit cyclooxygenase activity. The aqueous and chloroform extracts decreased the edema induced in the hind-paw and the number of neutrophils migrating into the peritoneal cavity, whereas the ethanol extract only decreased the number of neutrophils. The anti-inflammatory agents indomethacin and dexamethasone also decreased carrageenan-induced edema and neutrophil migration. The aqueous extract inhibited prostaglandin E2 production from [14C]arachidonic acid. The chemical tests performed in the aqueous extract for anthraglycosides, reductor sugars and cardiotonic glycosides were positive. In the ethanol extract, the chemical tests performed for saponins, carbohydrates naftoquinones, sterols, triterpenoids and anthraquinones were also positive. In the chloroform extract, the chemical tests performed for sterols type delta 5, and anthraquinones were positive. These results demonstrated that the extracts of Aloe vera gel have anti-inflammatory activity and suggested its inhibitory action on the arachidonic acid pathway via cyclooxygenase.

Isolation Of A Stimulatory System In Aloe Extract
Dr. Davis

A set of experiments Dr. Davis and team members conducted involving the “Isolation of a Stimulatory System in Aloe Extract.” This study was done as a follow up on a previous clinical study in which a 50% ethanol extract was done to evaluate a croton oil-induced ear swelling assay. In this test, the Davis reserach team found that the “superanant fraction” decreased inflammation when applied topically by 29.2%, and the precipitate decerased inflammation by 12.1%. Even more significantly, the precipitate wound healing activity was increased by an average of 47.5. In the original study the superanant exhibited a 78% anti-inflammatory activity of Aloe vera, and promised to offer a low-cost, natural substance that could be used to manage imflammation and wounds in the lower extremeties.

In the new study, however, the Davis research team did not attempt to alter the original alcohol (or ethanol percentage). Instead, they ultracentrafuged the Aloe compound and then froze the two fractions to approximately – 80^oC. Then they applied the superanant (freeze-dried) powder and the Aloe vera freeze dried powder to a test group and control group of white mice. The precipitate (combination of Aloe and ethanol) tested better for wound healing than the superanant and the Aloe each on their own. In fact the superanant showed no ability to heal wounds, the Aloe vera showed an ability of wound healing and anti-inflammatory capacities ranging from a 29.4% ratio, yet exhibited a higher anti-inflammatory activity ratio of 37.4 more than that of either the precipitate or the superanant, and the precipitate combination showed a range of 47.1 in wound healing yet a lower 12.1 anti-inflammatory activity. It was concluded in both these tests that: “Aloe vera has anti-inflammatory components such as amino acids, vitamin C, aspirin like compounds, and mannose which can normalize the acute vascular response. Aloe vera can block the polymorphonuclear leucocyte response, but does not reduce connective tissue formation.”

Part of the process of this particular Davis et al. study also entailed the attempt to isolate a polysaccharide component and glycoprotein (enzyme) constituent in the Aloe vera that might hold the key to all this effective activity. In this case the polysaccharide in question was mannose phosphate. In the singular context, it was determined that the mannose phosphate did serve as a binding agent to the same receptors that formed a positive growth medium for accelerated wound healing, as well as anti-inflammatory activity. However, the reserchers arrived at the conclusion that it would be an all but futile determination to credit any complex saccharide or single element for the total activity attributable to the Aloe vera complex itself.

Role Of Thromboxane In Experimental Inadvertent Intra-Arterial Drug Injections
Zachary LS; Smith DJ Jr; Heggers JP; Robson MC; Boertman JA; Niu XT; Schileru RE; Sacks RJ
J Hand Surg [Am] 12(2):240-5 1987 Mar

Inadvertent intra-arterial injection of drugs produces a well-defined clinical syndrome whose pathophysiology remains unclear. This study was designed to determine the role of the inflammatory mediator, thromboxane, in intra-arterial drug injections. The rabbit ear model, as described by Kinmonth and Sheppard, was used. Five of the experimental groups were treated with specific or nonspecific thromboxane blocking agents and two groups served as controls. Immunohistochemical staining of the control ears showed elevated levels of thromboxane within the first 6 hours postinjury. The specific thromboxane blocking agents, methimazole and Aloe vera, showed almost complete blockade of thromboxane production. The percentage of ear survival was significantly greater in the group treated with topical Aloe vera (p less than 0.05) and even greater survival was achieved in the combined Aloe vera/methimazole group (p less than 0.01). On the basis of these results, we have begun treatment of such injuries with specific and nonspecific thromboxane blocking agents.