Discovery of novel 2-oximino-2-indolylacetamide derivatives as potent anticancer agents capable of inducing cell autophagy and ferroptosis.

A series of 2-oximino-2-indolylacetamide derivatives were designed, synthesized and evaluated for their antitumour effects. Among them, 4d exhibited the most potent antiproliferative effect in vitro on the tested human cancer cells. Additionally, 4d significantly induced cell apoptosis, caused mitochondrial dysfunction, promoted Bax, cleaved-PARP and p53 expression and inhibited Bcl-2 expression in 5-8F cells. Moreover, 4d remarkably promoted autophagosome formation, leading to cell apoptosis. Further investigation indicated that 4d could trigger cell death through cell ferroptosis, including increased ROS generation and lipid peroxidation and decreased glutathione peroxidase 4 (GPx4) expression and glutathione (GSH) levels. More importantly, 4d induced 5-8F cell death by activating ROS/MAPK and inhibiting the AKT/mTOR and STAT3 signalling pathways. Interestingly, 4d significantly suppressed tumour growth in a 5-8F cell xenograft model without obvious toxicity to mice. Overall, these results demonstrate that 4d may be a potential compound for cancer therapy.

Preparation of kakkatin derivatives and their anti-tumor activity.

BACKGROUND: Modern pharmacological studies have confirmed that plant-derived compounds from Puerariae flos (PF) has significant biological activities against liver damage, tumors and inflammation. Kakkatin is an isoflavone polyphenolic compound isolated from PF flower. However, the effect of kakkatin and its derivatives on anti-tumor has not been well explored. AIM: To design and synthesize a kakkatin derivative [6-(hept-6-yn-1-yloxy)-3-(4-hydroxyphenyl)-7-methoxy-4H-chromen-4-one (HK)] to explore its anti-tumor biological activity. METHODS: Hept-6-yn-1-yl ethanesulfonate was introduced to replace hydrogen at the hydroxyl position of kakkatin phenol, and the derivative of kakkatin was prepared; the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to detect cell viability, a clone formation assay was adopted to detect cell proliferation, apoptosis, necrosis, and cell cycles were analyzed by Annexin V/propidium iodide staining and flow cytometry. Cell migration and invasion ability were evaluated by cell scratch assay and transwell assay. The potential mechanism of HK on hepatocellular carcinoma (HCC) SMMC-7721 cells was explored through network pharmacology and molecular docking, and finally real-time PCR assays was used to verify the potential targets and evaluate the biological activity of HK. RESULTS: Compared with kakkatin, the modified HK did not significantly increase the inhibitory activity of gastric cancer MGC803 cells, but the inhibitory activity of HCC SMMC-7721 cells was increased by about 30 times, with an IC50 value of 2.5 µM, and the tumor inhibition effect was better than cisplatin, which could significantly inhibit the cloning, invasion and metastasis of HCC SMMC-7721 cells, and induce apoptosis and G2/M cycle arrest. Its mechanism of action is mainly related to the upregulation of PDE3B and NFKB1 target proteins in the cAMP pathway. CONCLUSION: HK have a significant inhibitory effect on HCC SMMC-7721 cells, and the targets of their action may be PDE3B and NFKB1 proteins in the cAMP pathway, making it a good lead drug for the treatment of HCC.

Alkaloids from Corydalis saxicola and their antiproliferative activity against cancer cells.

Eight undescribed alkaloids named corydalisine D-K (1-7), including one isoquinoline benzopyranone alkaloid (1), one benzocyclopentanone alkaloid (2), four benzofuranone alkaloids (3, 4, and 5a/5b) and two protoberberine alkaloids (6 and 7), along with fourteen known ones, were isolated from the Corydalis saxicola. Their structures, including absolute configurations, were unambiguously identified using spectroscopic techniques, single-crystal X-ray diffraction and electron circular dichroism calculation. Compounds 2, 14 and 21 exhibit antiproliferative activity against five cancer cell lines. The aporphine alkaloid demethylsonodione (compound 14), which exhibited the best activity (IC50 = 3.68 ± 0.25 µM), was subjected to further investigation to determine its mechanism of action against the T24 cell line. The molecular mechanism was related to the arrest of cell cycle S-phase, inhibition of CDK2 expression, accumulation of reactive oxygen species (ROS), induction of cell apoptosis, inhibition of cell migration, and activation of p38 MAPK signaling pathway. The results indicated that 14 could be used as a potential candidate agent for further development of anti-bladder transitional cell carcinoma.

New alkaloids and their in vitro antitumor activity of Corydalis balansae.

The chemical investigation on Corydalis balansae resulted in the isolation of three previous undescribed compounds (1, 10, and 11) and 17 known compounds. Compound 1 and 2 were obtained as two lignanamide dimers, and compound 11 had a spiro [benzofuranone-benzazepine] skeleton, which was found in Corydalis for the first time. The structures of new compound were determined by the detailed analysis of 1D/2D NMR, UV, and IR data. Absolute configurations of compounds 10 and 11 were defined by their crystal X-ray diffraction data and calculations of electronic circular dichroism (ECD). The CCK-8 method was used to assay the inhibition effect of all the compounds on the growth of Hela, MGC-803, A549, and HepG2 cancer cells. Compound 2, 13, and 14 showed moderate inhibitory activity against the tested cell lines. Compound 2 exhibited potential antitumor activity against MGC-803 cells with an IC50 value of 20.8 µM, while the positive control etoposide was 17.3 µM. Furthermore, results from the cellular-mechanism investigation indicated that compound 2 could induce S-phase cell-cycle arrest and MGC-803 cells apoptosis, which was triggered by the up-regulation of PARP1, caspase-3 and -9, Bax, and down-regulation of Bcl-2. The 2-induced strong apoptosis indicated that compound 2 had good potential as an antitumor lead compound.