Solanum nigrum L. (Longkui) is one the most widely used anticancer herbs in traditional Chinese medicine. α‑Solanine is an important ingredient of S. nigrum L. and has demonstrated anticancer properties in various types of cancer. However, the effects of α‑solanine on colorectal cancer remain elusive. The aim of the present study was to assess the effects of α‑solanine on human colorectal cancer cells. The results demonstrated that α‑solanine inhibited the proliferation of RKO cells in a dose‑ and time‑dependent manner. In addition, α‑solanine arrested the cell cycle at the G0/G1 phase and suppressed the expression levels of cyclin D1 and cyclin‑dependent kinase 2 in RKO cells. α‑Solanine induced apoptosis of RKO cells, as indicated by morphological changes and positive Annexin‑FITC/propidium iodide staining. Additionally, α‑solanine activated caspase‑3, ‑8 and ‑9 in RKO cells, which contributed to α‑solanine‑induced apoptosis. α‑Solanine also increased the generation of reactive oxygen species, which contributed to caspase activation and induction of apoptosis. α‑Solanine inhibited the migration, invasion and adhesion of RKO cells, as well as the expression levels and activity of matrix metalloproteinase (MMP)‑2 and MMP‑9. In addition, α‑solanine inhibited cell proliferation, activated caspase‑3, ‑8 and ‑9, induced apoptosis, and inhibited the migration and invasion of HCT‑116 cells. Furthermore, α‑solanine inhibited tumor growth and induced apoptosis in vivo. These findings demonstrated that α‑solanine effectively suppressed the growth and metastatic potential of human colorectal cancer.
Keywords: colorectal carcinoma; α-solanine; proliferation; cell cycle; apoptosis; metastasis.