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.