The effect of purple sweet potato (Ipomea batatas L.) extract gel toward TNF-α expression and skin collagen density on rats (Rattus norvegicus) with open wound models

Abstract Open wound is a damage to the skin or tissues under the skin that can be caused by sharp objects or fights between animals. Purple sweet potato ( Ipomea batatas L ) contains some bioactive substances, such as anthocyanin and tannin, which help to prevent the prolongation of the inflammatory phase and increase fibroblast proliferation. The aim of this research was to determine the effect of purple sweet potato extract gel toward the expression of TNF-α and skin collagen density on rats with open wound model. The open wound was made circular using a modified Morton method. This study used a completely randomized design with 20 rats, Wistar strain aged 12 weeks, weighing 150-200 g, divided into 5 groups with 4 replicates. TNF-α expression observed in immunohistochemistry method and analyzed using one-way ANOVA statistical test, followed by Honestly Significant Difference Test. The density of collagen with Masson Trichome staining was analyzed by the Kruskal-Wallis nonparametric statistic test with Mann-Whitney-U test. The results showed that the purple sweet potato extract as a therapy for open wounds was significantly reduce the TNF-α expression and increase collagen density. The conclusion is that the purple sweet potato extract with 30% concentration is the most effective therapy in increasing collagen density but not very effective in reducing TNF-α expression.