Abstract

Dietary Administration of Aloe Vera Gel Extract Inhibits Intestinal Polyp Formation in Min Mice Fed a High-Fat Diet

Chihara T, Shimpo K, Beppu H, Kaneko T, Higashiguchi T, Sonoda S, Tanaka M, Yamada M and Abe F

Objectives: Aloe vera gel extract (AVGE) was recently produced using a new procedure with supercritical carbon dioxide fluid. AVGE was proven safe in acute toxicity and subchronic toxicological tests, and was shown to contain five phytosterols (Aloe-sterols). AVGE may inhibit the accumulation of visceral fat due to the functions of Aloe-sterols, which may, in turn, contribute to preventing metabolic syndrome. A meta-analysis previously revealed that obesity was positively associated with colon cancer. Therefore, we examined the effects of the dietary administration of AVGE on intestinal polyp formation in Apc-deficient Min mice fed a high-fat diet (HFD). Methods: Male Min mice were divided into normal diet (ND), HFD, and AVGE groups. The ND group was fed an AIN-93G diet, the HFD group was given modified high-fat AIN-93G diets, and the AVGE group was fed HFD 0.0125% containing AVGE for 65 days. Results: Between days 56 and 65, body weights were significantly lower in the HFD group than in the ND group, and were slightly lower in the AVGE group. The total number of polyps (≥0.5 mm in diameter) in the small intestine and total (small and large) intestine was significantly lower in the AVGE group than in the HFD group. When intestinal polyps were categorized by their size into 0.5-1.4, 1.5-2.4, or ≥2.5 mm, the number of large polyps (≥2.5 mm) in the small intestine was significantly lower in the AVGE group than in the HFD group. Plasma HMW adiponectin levels were significantly higher in the AVGE group than in the HFD group. Conclusion: The dietary administration of AVGE reduced the total number of polyps and number of large polyps. By combining our results with other findings, the inhibition of cell proliferation by HMW adiponectin was suggested as one of the mechanisms underlying the suppression of intestinal polyp formation.