Acetone Extract of Cornus officinalis Leaves Exerts Anti-Melanoma Effects via Inhibiting STAT3 Signaling

Ruiqi Xu,1,2 Mengnan Zeng,1,2 Yuanyuan Wu,1,2 Shengchao Wang,1,2 Beibei Zhang,1,2 Jingke Zhang,1,2 Yuxuan Kan,1,2 Benke Li,1,2 Bing Cao,1,2 Xiaoke Zheng,1,2 Weisheng Feng1,2 1School of Pharmacy, Henan University of Traditional Chinese Medicine, Zhengzhou, People’s Republic of China; 2The Engineering and Technology Center for Chinese Medicine Development of Henan Province, Zhengzhou, People’s Republic of ChinaCorrespondence: Xiaoke Zheng; Weisheng FengSchool of Pharmacy, Henan University of Traditional Chinese Medicine, 156 Jinshui East Road, Zhengzhou, 450046, People’s Republic of ChinaTel +86-371-6019-0296Email zhengxk.2006@163.com; fwsh@hactcm.edu.cnPurpose: This research aims to investigate the intervention and mechanism of 50% acetone extract of C. officinalis leaves (SZYY) on melanoma xenografts.Patients and Methods: Tumor size and cardiac function were measured via ultrasound. The accumulation of 2-deoxy-D-glucose (2-DG) in tumor tissue was examined with near-infrared in vivo imaging. Flow cytometry was performed to assess apoptosis and reactive oxygen species (ROS) levels in tumor and immune cells in spleen. The levels of inflammatory cytokines in serum were detected by cytometric bead array. The expression of proliferation-, apoptosis-, and angiogenesis-related proteins in tumor cells was measured to evaluate the underlying mechanisms. Subsequently, the effects of four compounds separated from SZYY on the proliferation and migration of A375 cells and STAT3 signaling were examined. The peak identification and contents of the four components were performed via high-performance liquid chromatography (HPLC). Finally, we evaluated the inhibitory effects of STAT3 overexpression on the cytotoxic activity of four constituents in A375 cells.Results: SZYY inhibited the growth and glycolysis of melanoma xenograft in mice, improved cardiac function, increased the percentages of macrophages, neutrophils, and lymphocytes in spleen, reduced the levels of IL-6, IL-17A, TNF-α, and IFN-γ in serum, promoted apoptosis and oxidative stress in tumor tissues, and inhibited STAT3 phosphorylation and expression of angiogenic factors. Chemical analysis showed that SZYY is rich in loganin, rutin, triohimas C, and triohimas D, which all could restrain the proliferation and migration of A375 cells and inhibit the phosphorylation and nuclear translocation of STAT3. Moreover, STAT3 overexpression could diminish the cytotoxic activity of four compounds on A375 cells.Conclusion: SZYY could exert anti-melanoma effects via inhibiting STAT3 signaling to induce apoptosis and inhibit tumor angiogenesis. Its active ingredients might be loganin, rutin, triohimas C, and triohimas D.Keywords: Cornus officinalis, melanoma, STAT3, apoptosis, angiogenesis