The mechanism of flavonoids from Cyclocarya paliurus on inhibiting liver cancer based on in vitro experiments and network pharmacology

Combined metabolomic and transcriptomic analysis reveals the key genes for triterpenoid biosynthesis in Cyclocarya paliurus

BACKGROUND

Cyclocarya paliurus is a high-value tree, and it contains a variety of bioactive secondary metabolites which have broad application prospects in medicine, food and health care. Triterpenoids can improve the bioactive function of C. paliurus health tea and also improve the efficacy of health care tea.

RESULTS

The results of this study showed that there were 69 kinds were terpenoids, and triterpenoids accounted for more than 80%. We excavated 5 kinds of triterpenoid metabolites with high content and significant difference dynamics, namely, corosolic acid, asiatic acid, maslinic acid, ursolic acid and oleanolic acid. The co-expression analysis identified CYP71D8 and CYP716A15 co-expressed with β-AS may generate oleanane type triterpenoids by modifying β-amyrin, while CYP71AN24 and CYP98A2 co-expressed with LUS may play a key role in lupine type triterpenoids biosynthesis. MYB,Whirly,WRKY and bHLH families, which showed strong correlation with function genes, may play an important role in the regulation of P450 and OSC expression. A total of 20 modules were identified by WGCNA analysis, and CYP71AU50 and CYP716A15 in tan and orange modules may play a major role in the synthesis of oleanolic acid, ursolic acid and asiatic acid, while CYP82D47 in lightcyan 1 module may be the hub gene for the biosynthesis of corosolic acid and maslinic acid.

CONCLUSIONS

Our findings mined candidate genes closely related to triterpenoid synthesis in C. paliurus. The results of this paper can provide scientific reference for breeding high-content triterpenoid varieties of C. paliurus.

Combination of transcriptomic and proteomic approaches helps unravel the mechanisms of luteolin in inducing liver cancer cell death via targeting AKT1 and SRC

Introduction

Luteolin, a natural compound commonly used in traditional Chinese medicine, shows clinical potential as an anti-liver cancer agent. The mechanisms underlying the anti-liver cancer effect of luteolin are limited versus those reported for other cancers. Accordingly, this study was conducted to bridge the existing knowledge gap.

Methods

Transcriptomic and proteomic analyses of the response of the hepatocellular carcinoma cell line HuH-7 to luteolin were conducted, and a possible pathway was elucidated using confocal laser scanning microscopy (CLSM), flow cytometry, western blotting, qRT-PCR and bio-layer interferometry assay to systematically explore the possible mechanisms underlying the inhibition of the proliferation of liver cancer cells by luteolin.

Results and Discussion

Results showed that luteolin significantly inhibited HuH-7 cell proliferation. Transcriptomic and proteomic analyses collectively revealed that luteolin could promote cell cycle arrest and apoptosis in HuH-7 cells through transcription factors p53, nuclear factor kappa B (NF-κB), FOXO, ATF2, and TCF/LEF via AKT1, as well as the KEAP-NRF and SRC-STAT3 pathways. Furthermore, AKT1 and SRC were identified as the 2 targets of luteolin. Nuclear translocation of transcription factors p53 and NF-κB were affected by luteolin administration. Additionally, AKT1 activity affected normal metabolism in HuH-7 cells and resulted in the accumulation of reactive oxygen species, which activated MOMP and further promoted apoptosis. Our results systematically elucidate the mechanism of luteolin in inhibiting the proliferation of liver cancer cells, mainly through cell cycle arrest and apoptosis via targeting AKT1 and SRC.

Anti-proliferative Effects of Pinocembrin Isolated From Anomianthus dulcis on Hepatocellular Carcinoma Cells

BACKGROUND

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer. Anomianthus dulcis (Dunal) J.Sinclair (syn. Uvaria dulcis) has been used in Thai traditional medicine in various therapeutic indications. Phytochemical constituents of A. dulcis have been isolated and identified. However, their effects on liver cancer and the associated mechanisms have not been elucidated.

METHODS

Dry flowers of A. dulcis were extracted using organic solvents, and chromatographic methods were used to purify the secondary metabolites. The chemical structures of the pure compounds were elucidated by analysis of spectroscopic data. Cytotoxicity against HCC cells was examined using SRB assay, and the effects on cell proliferation were determined using flow cytometry. The mechanisms underlying HCC inhibition were examined by molecular docking and verified by Western blot analysis.

RESULTS

Among 3 purified flavonoids, pinocembrin, pinostrobin, and chrysin, and 1 indole alkaloid (3-farnesylindole), only pinocembrin showed inhibitory effects on the proliferation of 2 HCC cell lines, HepG2 and Li-7, whereas chrysin showed specific toxicity to HepG2. Pinocembrin was then selected for further study. Flow cytometric analyses revealed that pinocembrin arrested the HCC cell cycle at the G1 phase with a minimal effect on cell death induction. Pinocembrin exerted the suppression of STAT3, as shown by the molecular docking on STAT3 with a better binding affinity than stattic, a known STAT3 inhibitor. Pinocembrin also suppressed STAT3 phosphorylation at both Tyr705 and Ser727. Cell cycle regulatory proteins under the modulation of STAT3, namely cyclin D1, cyclin E, CDK4, and CDK6, are substantially suppressed in their expression levels.

CONCLUSION

Pinocembrin extracted from A. dulcis exerted a significant growth inhibition on HCC cells via suppressing STAT3 signaling pathways and its downstream-regulated genes.