Antitumor properties of an ethanolic extract from seeds of Solanum melongena L.: in vitro and in vivo study in colon cancer

Natural compound research is a promising area to develop new agents with higher efficacy for the treatment of colon cancer (CRC), the second most common cause of cancer deaths worldwide. In this context, Solanum melongena L., also known as eggplant, is a widely consumed vegetable with numerous health benefits, including antioxidant, anti-inflammatory and antiproliferative properties. S. melongena L. S0506, a new material with a striated pattern on the skin, was selected to determine its antitumor capacity and the molecular mechanisms underlying the therapeutic effects. An ethanolic extract from S. melongena L. S0506 defatted seeds was assayed in CRC, glioblastoma and pancreatic cancer cells lines showing a high antiproliferative activity. The extract showed a high content of bioactive compounds, highlighting the presence of kaempferol 3-sophorotrioside, capsianoside III and protodiosin which induced cell cycle arrest in cancer cell lines and quercetin capable of reducing inflammation and oxidative stress in AOM/DSS colon cancer model. Analysis of the extract action mechanism showed a clear activation of the apoptotic and autophagic pathways. Interestingly, a decrease in angiogenesis and a reduction of cancer stem cell subpopulations were detected. In vivo studies using an experimental model of AOM/DSS-induced CRC corroborated the antitumor effect of the ethanolic extract of S. melongena L. S0506, which was able to reduce number of polyps by 62.5%. Our findings suggest that S. melongena L. S0506 could be a potential source of new antitumor agents in colon cancer treatment although further research will be necessary to determine its applicability in clinical settings.