Effect of a Polyphenol-Rich Extract from Aloe vera Gel on Experimentally Induced Insulin Resistance in Mice

Insulin resistance, which precedes type 2 diabetes mellitus (T2DM), is a widespread pathology associated with the metabolic syndrome, myocardial ischemia, and hypertension. Finding an adequate treatment for this pathology is an important goal in medicine. The purpose of the present research was to investigate the effect of an extract from Aloe vera gel containing a high concentration of polyphenols on experimentally induced insulin resistance in mice. A polyphenol-rich Aloe vera extract (350 mg/kg) with known concentrations of aloin (181.7 mg/g) and aloe-emodin (3.6 mg/g) was administered orally for a period of 4 weeks to insulin resistant ICR mice. Pioglitazone (50 mg/kg) and bi-distilled water were used as positive and negative controls respectively. Body weight, food intake, and plasma concentrations of insulin and glucose were measured and insulin tolerance tests were performed. The insulin resistance value was calculated using the homeostasis model assessment for insulin resistance (HOMA-IR) formula. Results showed that the polyphenol-rich extract from Aloe vera was able to decrease significantly both body weight ( p < 0.008) and blood glucose levels ( p < 0.005) and to protect animals against unfavorable results on HOMA-IR, which was observed in the negative control group. The highest glucose levels during the insulin tolerance curve test were in the negative control group when compared to the Aloe vera extract and pioglitazone treated mice ( p < 0.05). In conclusion, Aloe vera gel could be effective for the control of insulin resistance.

Aloe vera leaf gel: a review update

Research since the 1986 review has largely upheld the therapeutic claims made in the earlier papers and indeed extended them into other areas. Treatment of inflammation is still the key effect for most types of healing but it is now realized that this is a complex process and that many of its constituent processes may be addressed in different ways by different gel components. A common theme running though much recent research is the immunomodulatory properties of the gel polysaccharides, especially the acetylated mannans from Aloe vera, which are now a proprietary substance covered by many patents. There have also been, however, persistent reports of active glycoprotein fractions from both Aloe vera and Aloe arborescens. There are also cautionary investigations warning of possible allergic effects on some patients. Reports also describe antidiabetic, anticancer and antibiotic activities, so we may expect to see a widening use of aloe gel. Several reputable suppliers produce a stabilized aloe gel for use as itself or in formulations and there may be moves towards isolating and eventually providing verified active ingredients in dosable quantities

Beneficial effect of Aloe on wound healing in an excisional wound model

Recent evidence from in vitro and in vivo experiments suggests that topical antimicrobials may be toxic to fibroblasts and keratinocytes and retard wound healing. The purpose of this study was to determine the effects of Aloe, a potential wound-healing agent, on wound contraction in excisional wounds treated with topical antimicrobials. Sprague-Dawley rats were prepared with four 1.5 cm2 dorsal defects through the skin and panniculus. The animals were divided into five groups (n = 10 per group): (1) Aloe, (2) NaOCl solution (0.025%), (3) mafenide acetate, (4) mafenide acetate + Aloe, and (5) control. Wounds were treated topically for 14 days 3 times a day. Serial standard photographs and serial wound planimetry were performed weekly. Following healing, the breaking strength of each resultant scar was determined using an Instron tensiometer. Kruskal-Wallis, ANOVA, and multiple comparison methods were used for data analysis. Aloe and NaOCl solution significantly accelerated wound contraction (p < 0.05). In the mafenide acetate + Aloe group, contraction was similar to the control, whereas the mafenide acetate alone retarded wound healing. The addition of Aloe in combination and alone in wounds increased the breaking energy when compared to controls (p < 0.05). Aloe appears to expedite wound contraction and neutralize the wound retardant effect seen with the topical mafenide acetate alone. This effect appears to be due to an increased collagen activity, which is enhanced by a lectin, consequently improving the collagen matrix and enhancing the breaking strength.