Incorporating Preservatives And Additives On Aloe Vera Leaf Gel For Microbiological Stability And Oxidative Resistance During Storage: Wound Healing Assay In Vivo

Abstract

The therapeutic properties of Aloe vera gel are widely recognized. However, it should be stabilized immediately after extraction to avoid its rapid deterioration upon exposure to environmental conditions. In this study, the fresh gel was stabibized by incorporating benzoic acid (0.1 %), vitamin E (300 ppm) and xanthium gum (0.2 %) as preservatives and additives. Then, we monitored pH change, total antioxidant activity and microbial growth throughout the storage at 4°C and 25°C. At 4°C, the stabilized gel with preservatives showed the best antioxidative stability with maintaining the percentage DPPH inhibition up to 50 % after 30 days of storage Adding benzoic acid on fresh gel as an antimicrobial and maintaining an acidic pH (3.57-3.74) during storage were found to be effective against the development of spoilage micro-organisms. Unlike, the no stabilized gels which showed a microbial contamination with an increase in pH values. Furthermore, the healing effectiveness of the stable gel applied topically one daily to mice’s skin wounds until wound closure was assessed by wound contraction every 2 days. Saline solution and Madécassol® cream are used as negative and positive controls respectively. The stable gel used at both concentration on mice groups showed a significant effect on wound closure rate and the shortened healing process compared to control groups. The wound healing began on the 2th post operative day with an increase in wound contraction from 70 and 75 % to 100 % on the 10th day. Thus, our stabilized gel maintained its wound healing efficacy. Keywords: Aloe vera leaf gel; stabilization; antioxidative stability; microbiological stability; therapeutic efficacy; wound healing.