Euphornin L promotes lipid clearance by dual regulation of LDLR and PCSK9.

Our previous study identified euphornin L as an active lipid-lowering compound in high-fat diet-fed Golden Syrian hamsters. The aim of the present study was to investigate the mechanisms underlying the lipid-lowering effects of euphornin L. Euphornin L in HepG2 cells was assessed via DiI-LDL update assays and found to increase LDL-update and LDLR protein levels. RNA interference assays demonstrated that its LDL-update effects were LDLR-dependent. Dual luciferase reporter and mRNA stability assays revealed that euphornin L had little effect on LDLR mRNA transcription but lengthened the half-life of LDLR mRNA by activating ERK protein in cells. Euphornin L decreased the secretion of PCSK9 protein and alleviated PCSK9-mediated LDLR protein degradation. In vivo experiments in hamsters, which were treated with euphornin L (30 mg/kg/day) for 3 weeks, confirmed these findings. LDLR protein levels in liver tissue were upregulated, while PCSK9 protein levels in serum were downregulated. Altogether, the present study demonstrated that euphornin L increased LDLR protein levels by dual regulation of LDLR mRNA and PCSK9 protein, and represented an active compound for lipid-lowering drug development.

Euphornin reduces proliferation of human cervical adenocarcinoma HeLa cells through induction of apoptosis and G2/M cell cycle arrest.

BACKGROUND: The plant Euphorbia helioscopia L. has been used in traditional Chinese medicine for treating various disorders such as tuberculosis and edema. The aim of this study was to investigate the effect of euphornin, a bioactive compound isolated from E. helioscopia, on proliferation of human cervical adenocarcinoma HeLa cells by analyzing cell viability, rate of apoptosis, and cell cycle progression. MATERIALS AND METHODS: The sulforhodamine B assay was used to study the effect of euphornin on the proliferation of HeLa cells. Morphological changes to cell nuclei were identified after Hoechst 33342 staining. Mitochondrial membrane depolarization (MMP) was analyzed after staining with JC-1 dye. The influence of euphornin on the apoptosis rate was analyzed by Annexin V/propidium iodide double staining. Fluorescence-activated cell sorting was applied to investigate the influence of euphornin on cell cycle progression. Proteins were obtained from HeLa cells and analyzed by Western blots. RESULTS: A cell viability assay showed that euphornin inhibited proliferation of HeLa cells in a dose-dependent and time-dependent manner. Euphornin also induced apoptosis in a concentration-dependent manner, with the rates of apoptosis ranging from 25.3% to 52.6%. A high concentration of euphornin was found to block HeLa cells at the G2/M stage. A Western blot analysis suggested that euphornin might exhibit antitumor activity by inducing apoptosis. Euphornin treatment altered the ratio of Bax/Bcl-2 in HeLa cells, which led to the release of cytochrome complex. The levels of cleaved caspase-3, caspase-8, caspase-9, and caspase-10 were also markedly increased by euphornin treatment. Analysis of cell cycles indicated that euphornin induced cell cycle arrest by increasing the level of the phospho-CDK1 (Tyr15) protein. The various assays demonstrated that euphornin treatment resulted in a significant suppression of cell growth accompanied by G2/M cell cycle arrest and increased rate of apoptosis via mitochondrial and caspase pathways. CONCLUSION: Our findings suggest that euphornin has the potential to be used as a cancer therapeutic agent against human cervical adenocarcinoma.

Study on the Effect and Mechanism of Euphornin Inducing the Apoptosis of Cervical Cancer Hela Cells / 中国药房

OBJECTIVE:To study induction effect of euphornin on the apoptosis of cervical cancer Hela cells and its mechanism. METHODS:The cervical cancer Hela cells were divided into blank control group,cisplatin group(positive control, 10 mg/L) and euphornin low-dose,medium-dose and high-dose groups (50,100,200 mg/L). They were treated with relevant medicine. The inhibitory effect of Hela cells proliferation was tested by MTT assay after 24,48,72 h of medicine treatment. The apoptotic rate of Hela cells was measured by flow cytometry after 48 h of medicine treatment. Morphology of nucleus was detected by Hoechst 33258 staining. The protein expression of Cyt-C,Bcl-2,Bax,Caspase-3,Caspase-8,Caspase-9 and Caspase-10 were detected by Western blot assay. RESULTS:Compared with blank control group,inhibitory rate of cell proliferation and cell apoptosis rate were increased significantly in cisplatin group and euphornin groups(P＜0.05 or P＜0.01),and obvious staining, deformation,shrinking,fragmentation or apoptotic bodies was found in nucleus. Compared with blank control group,the protein expression levels of Cyt-C,Caspase-8 and Caspase-9 in euphornin low-dose,medium-dose and high-dose groups were increased significantly,while the protein expression level of Bcl-2 and Bcl-2/Bax ratio were decreased significantly(P＜0.05 or P＜0.01);the protein expression levels of Bax,Caspase-3 and Caspase-10 in euphornin medium-dose and high-dose groups were increased significantly(P＜0.05 or P＜0.01). CONCLUSIONS:Euphornin can significantly inhibit the proliferation of Hela cell and promote cell apoptosis,the effect of which will be achieved by activating the Caspase-dependent mitochondrion apoptosis pathway.