Ethoxychelerythrine as a potential therapeutic strategy targets PI3K/AKT/mTOR induced mitochondrial apoptosis in the treatment of colorectal cancer.

Several alkaloids found in the Zanthoxylum genus have demonstrated significant anticancer activity. However, the antitumor effects of Ethoxychelerythrine (Eth) have not been previously reported. Cell viability, colony formation, apoptosis and cell cycle analysis, intracellular and reactive oxygen species (ROS), mitochondrial membrane potential (MMP) levels of Eth against SW480 cells were evaluated. Subcutaneously transplanted SW480 cells model was used to determine the effect of Eth on tumor growth in vivo. Inflammation levels, angiogenic factors, pathological observations, quantitative reverse-transcription PCR (qRT-PCR), quantitative proteomics, metabolite profiles and western blotting were conducted. It found that Eth significantly inhibited the proliferation of SW480 and HT29 cells in vitro, with stronger inhibitory activity observed against SW480 cells. Therefore, subsequent studies focused on SW480 cells. In vitro, we observed that Eth arrested the cell cycle at the G0/G1 phase, decreased MMP levels, elevated cellular ROS levels, and induced mitochondrial apoptosis. In vitro, Eth significantly inhibited tumor proliferation and metastasis, and regulated the molecule levels of angiogenesis and inflammatory factors in serum, as well as apoptotic protein in tumor tissues. The serum proteomic revealed that the differential proteins were primarily involved in the PI3K/AKT/mTOR pathway, including laminin β1 (Lamb1), and type I collagen (Col1a1). Metabolomics showed that many abnormal levels of metabolites regulated by the PI3K/AKT/mTOR pathway were obviously reversed towards normal levels after Eth intervention. The correlation analysis between the two-omics revealed that different proteins in the PI3K/AKT pathway, particularly lactate dehydrogenase B (LDHB) and glutathione synthetase (GSS), can interact with most of different metabolites. In summary, Eth exerts anti-tumour effects by inhibiting the activation of the PI3K/AKT/mTOR pathway, which in turn activates mitochondrial apoptosis. Eth may be considered in the development of drugs for relieving colon cancer patients in the future.