Synergistic antitumor effects of rhein and doxorubicin in hepatocellular carcinoma cells.

The aim of this study was to investigate the synergistic antitumor activity of rhein and doxorubicin (DOX) and to elucidate the underlying mechanisms in hepatocellular SMMC-7721 and HepG2 cells. Cell growth curves, caspase-3 activity, and intracellular DOX accumulation were observed using an IncuCyte real-time video imaging system. Combination index was used to calculate synergistic potential of rhein and DOX. Cell apoptosis was detected by the Annexin V-FITC/PI apoptosis kit. Lactate dehydrogenase and adenosine triphosphate (ATP) levels were assessed using an assay kit. Oxygen consumption rates (OCR) and extracellular acidification rates were assessed by the Seahorse XFe96 Extracellular Flux Analyzer. Mitochondrial inner membrane potential (ΔΨm) was monitored with JC-1 fluorescence. Western blot analysis was used to detect the level of P-glycoprotein. Synergistic antiproliferative and proapoptotic effects were exerted by the combination of rhein at 10 µM and DOX at 2 µM in SMMC-7721 and HepG2 cells. Rhein could influenced the accumulation of DOX in both cells, which was associated with remarkably decreased mitochondrial energy metabolism and ATP levels. Rhein could reduce ΔΨm in both cells. mPTP, opener atractyloside (ATR) could accelerate the loss of ΔΨm, and further suppress the OCR induced by rhein. In contrast, the mPTP blocker cyclosporin A (Cs A) inhibited the loss of ΔΨm and the OCR induced by rhein. Our data indicate that a decline in mitochondrial energy metabolism was responsible for the synergistic antitumor effects of rhein and DOX in hepatocellular carcinoma cells. Reduction of ΔΨm and opening of mPTP inhibited the exchange of ATP/adenosine diphosphate between mitochondrial matrix and cytoplasm is the important mechanism.

Investigation of the pharmacodynamic substances in dahuang zhechong pill that inhibit energy metabolism.

ETHNOPHARMACOLOGICAL RELEVANCE: Dahuang Zhechong pill (DHZCP) is a commonly used traditional Chinese medicine for the treatment of hepatocarcinoma. AIM OF THE STUDY: Previous studies have found that DHZCP can exert anti-hepatocarcinoma effects and reverse drug resistance by inhibiting energy metabolism. The goal of this study was to further explore the pharmacodynamic substances that inhibit energy metabolism. METHODS: The components of DHZCP absorbed into plasma were identified by UHPLC-Q-TOF-MS/MS. The Swiss and STITCH databases were used for target collection. The DAVID database was used for pathway enrichment analysis. Cytoscape software was used for network construction. The CCK-8 method detected cell viability. Chemiluminescence was used to detect ATP levels. RESULTS: A total of 89 components absorbed into plasma were identified by UHPLC-Q-TOF-MS/MS. Based on this, 24 potential pharmacodynamic substances were selected by network pharmacology. Among them, 11 components such as rhein can significantly inhibit ATP levels. CONCLUSIONS: Rhein, emodin, chrysophanol, hypoxanthine, baicalein, baicalin, wogonoside, acteoside, formononetin, isoliquiritigenin, and glycyrrhizic acid were the pharmacodynamic substances responsible for inhibition of energy metabolism of DHZCP.

Effects of Dahuang zhechong pill on doxorubicin-resistant SMMC-7721 xenografts in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Dahuang zhechong pill (DHZCP) is a famous traditional Chinese medicinal prescription from the "Synopsis of Prescriptions of the Golden Chamber (Jin Kui Yao Lue)",Lue)", an ancient Chinese medical classic. DHZCP is commonly used for clinical treatment of liver cancer by promoting blood circulation to dissolve blood stasis and by removing pathogenic vegetations.vegetations. DHZCP-based treatment has been derived from Traditional Chinese Medicine (TCM) and is officially recorded in the Chinese Pharmacopoeia. AIM OF THE STUDY: The aim of this study was to investigate the ability of DHZCP to reverse doxorubicin (DOX) resistance of SMMC-7721 cells in a xenograft mouse model, and to explore the underlying mechanisms. MATERIALS AND METHODS: Liquid chromatography-mass spectrometry was used to verify the composition of DHZCP. H&E staining was used to observe the pathological changes in hepatocellular carcinoma samples. Intracellular DOX accumulation was observed as intrinsic fluorescence by microscopy. Cell apoptosis was detected by the TUNEL assay. Human antibody arrays were used to analyze the expression of apoptotic- and angiogenic-related proteins. ATP levels were assessed and western blots were used to detect the protein expression of key enzymes of energy metabolism. RESULTS: DHZCP significantly reduced the tumor volume and weight of subcutaneous xenografts of drug-resistant hepatoma cells, and combining DHZCP with lower doses of DOX significantly increased the content of DOX in tumor tissue, increased the apoptosis of hepatoma cells, and reversed Dox resistance. With respect to 43 apoptosis-associated proteins, DHZCP regulated the expression of 5 of them. When combined with low-dose DOX, the expression of 40 apoptosis-related proteins was significantly altered. With respect to 23 angiogenesis-associated proteins, DHZCP upregulated the expression of endostatin and inhibited the expression of matrix metallopeptidase 9. When combined with low-dose DOX, DHZCP significantly downregulated protein expression of urokinase receptor, as well as vascular endothelial growth factor receptors 2 and 3. Especially, DHZCP significantly inhibited the expression of key enzymes of the tricarboxylic acid cycle and of oxidative phosphorylation, reducing the level of ATP in tumor tissue. CONCLUSIONS: DHZCP inhibited the growth of DOX-resistant hepatocellular carcinoma subcutaneous xenografts in nude mice and promoted increased apoptosis caused by DOX, thus reversing DOX resistance. This was associated with a decline in energy metabolism and regulated expression of pro-apoptotic proteins.