Ethnopharmacological relevance: Tripterygium hypoglaucum (levl.) Hutch (Celastraceae) (THH) root is a traditional Chinese medicinal herb commonly used for treating autoimmune diseases and cancer. Alkaloid is one of the most bioactive components of THH extract. To evaluate the in vitro and in vivo antitumor properties of the total alkaloids of THH (THHta).
Materials and methods: THHta was extracted in pilot-scale. HCT116 cells were chose to establish human colon cancer xenograft model. The in vitro anti-tumor activity of THHta was tested by Cell malignant transformation test, Soft agar colony formation assay and MTT assay. The in vivo anti-tumor effect of THHta was confirmed by xenograft mouse model. THHta-induced apoptosis was examined by flow cytometry. The levels of apoptosis-related proteins were investigated by Western blot.
Results: TPA-induced cell transformation was significantly inhibited by THHta in JB6 Cl41 cells. THHta inhibits the growth of colon cancer cells in vitro in a significant dose-dependent manner. Compared to the control set, i.p. administration of THHta to xenograft mice significantly reduced both tumor weight and volume. Apoptosis induction of THHta was mediated by activation of caspase-3, PARP and inhibiting of Bcl-2, Bcl-xL and XIAP.
Conclusion: THHta was effective in inhibiting tumor growth both in vitro and in vivo at less toxic concentrations by inducing apoptosis which suggested it could be developed as a potential anticancer agent.
Keywords: 12-O-tetradecanog 1 phorbol-13-acetate; Alkaloid; Apoptosis; B-cell lymphoma 2; B-cell lymphoma-extra large; Bcl-2; Bcl-xL; DISC; DMSO; FADD; FBS; Fas associated death domain protein; HE; PARP; TBST; THH; THHta; TNF receptor associated death domain; TPA; TRADD; Traditional Chinese medicine; Tripterygium hypoglaucum (levl.) Hutch; Tripterygium hypoglaucum (levl.) Hutch (Celastraceae); Tris Buffered Saline Tween; X-linked inhibitor of apoptosis protein; XIAP; death-inducing signaling complex; dimethyl sulfoxide; fetal bovine serum; hematoxylin and eosin; poly ADP-ribose polymerase; total alkaloids of Tripterygium hypoglaucum (levl.) Hutch (Celastraceae).
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