Kushenol E Attenuates AOM/DSS-induced Colorectal Tumorigenesis in Mice, Inhibits Proliferation, and Induces Apoptosis in HT-29 Colorectal Cancer Cells.

INTRODUCTION: Kushenol E is a prenylated flavonoid derived from Sophora flavescens. Although preliminary studies have suggested that Kushenol E possesses anticancer activity, its effects and molecular mechanisms in Colorectal Cancer (CRC) remain largely unexplored. Therefore, this study investigated the therapeutical effects of Kushenol E and its underlying molecular mechanisms against CRC. METHODS: HT-29 cells, colorectal organoids, and an AOM/DSS-induced colorectal tumor model in mice were used. Cellular biomarkers related to growth, damage, programmed cell death, mitochondrial membrane integrity, and activation of the p38, ERK, and AKT signal cascades were measured. In vivo, survival rate, body weight, disease activity index, colon length, tumor volume, H&E staining, TUNEL assays, immunohistochemistry, and ELISA were assessed. RESULTS: Kushenol E inhibited HT-29 cell proliferation, induced apoptosis, increased the expression of mitochondrial apoptosis-related proteins Bax and Caspase-3, and reduced Bcl-2 expression. Kushenol E also reduced phospho-ERK and phospho-AKT levels while increasing phospho-p38. In CRC organoids, Kushenol E significantly reduced organoid diameter on day 3 (p < 0.01) and decreased organoid viability (p < 0.01). In AOM/DSS-treated mice, Kushenol E showed increased TUNEL positivity and Bax and caspase-3 expression, together with reduced Ki67 and PCNA expression. Moreover, ELISA analysis showed that Kushenol E reduced serum levels of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) and lowered the tumor-associated biomarker CEA. DISCUSSION: Kushenol E inhibited CRC cell and organoid growth and attenuated AOM/DSSinduced colorectal tumorigenesis. These effects are associated with mitochondrial apoptosis and alterations in p38/ERK/AKT signaling, and are accompanied by reduced inflammatory cytokine and CEA levels in vivo. CONCLUSION: Kushenol E has shown excellent antitumor activity against CRC and warrants further mechanistic, pharmacological, and safety evaluation.