13-Oxyingenol dodecanoate, a cytotoxic ingenol derivative, induces mitochondrial apoptosis and caspase-dependent Akt decrease in K562 cells

Ingenane-type diterpenoids inhibit non-small cell lung cancer cells by regulating SRC/PI3K/Akt pathway

Ingenane-type diterpenoids (ITDs) are distinct components of plants belonging to the genus Euphorbia. These compounds have significant cytotoxic effects on non-small cell lung cancer (NSCLC) cells. However, the underlying molecular mechanism has yet to be reported. To explore the mechanism of the anticancer effect of ITDs, we carried out a network pharmacology prediction study. PPI network suggested that SRC and PI3K had high levels of interaction. In addition, KEGG analysis revealed that these common targets were significantly enriched in the PI3K/Akt signalling pathway. 13-oxyingenol-dodecanoate (13OD) was used for validation after the biological evaluation of some ITDs against NSCLC cells. It demonstrated that 13OD could significantly inhibit the growth of NSCLC cells by inducing apoptosis. The results from molecular docking and Western blotting showed that 13OD interacted with SRC and PI3K and down-regulated the SRC/PI3K/Akt signalling pathway in NSCLC cells. This study provided the underlying mechanism of ITDs against NSCLC.

13-Oxyingenol-dodecanoate inhibits the growth of non-small cell lung cancer cells by targeting ULK1

Lung cancer is the leading cause of cancer deaths worldwide. Non-small cell lung cancer (NSCLC) accounts for 80-85% of all lung cancers. Euphorbia kansui yielded 13-oxyingenol-dodecanoate (13OD), an ingenane-type diterpenoid, which had a strong cytotoxic effect on NSCLC cells. The underlying mechanism and potential target, however, remained unknown. The study found that 13OD effectively inhibited the cell proliferation and colony formation of NSCLC cells (A549 and H460 cells), with less toxicity in normal human lung epithelial BEAS-2B cells. Moreover, 13OD can cause mitochondrial dysfunction, and apoptosis in NSCLC cells. Mechanistically, the transcriptomics results showed that differential genes were mainly enriched in the mTOR and AMPK signaling pathways, which are closely related to cellular autophagy, the related indicators were subsequently validated. Additionally, bafilomycin A1 (Baf A1), an autophagy inhibitor, reversed the mitochondrial damage caused by 13OD. Furthermore, the Omics and Text-based Target Enrichment and Ranking (OTTER) method predicted ULK1 as a potential target of 13OD against NSCLC cells. This hypothesis was further confirmed using molecular docking, the cellular thermal shift assay (CETSA), and Western blot analysis. Remarkably, ULK1 siRNA inhibited 13OD's toxic activity in NSCLC cells. In line with these findings, 13OD was potent and non-toxic in the tumor xenograft model. Our findings suggested a possible mechanism for 13OD's role as a tumor suppressor and laid the groundwork for identifying targets for ingenane-type diterpenoids.

13-oxyingenol dodecanoate derivatives induce mitophagy and ferroptosis through targeting TMBIM6 as potential anti-NSCLC agents

Ingenol diterpenoids continue to attract the attention for their extensive biological activity and novel structural features. To further explore this type of compound as anti-tumor agent, 13-oxyingenol dodecanoate (13-OD) was prepared by a standard chemical transformation from an Euphorbia kansui extract, and 29 derivatives were synthesized through parent 13-OD. Their inhibition activities against different types of cancer were screened and some derivatives showed superior anti-non-small cell lung cancer (NSCLC) cells cytotoxic potencies than oxaliplatin. In addition, TMBIM6 was identified as a crucial cellular target of 13-OD using ABPP target angling technique, and subsequently was verified by pull down, siRNA interference, BLI and CETSA assays. With modulating the function of TMBIM6 protein by 13-OD and its derivatives, Ca2+ release function was affected, causing mitochondrial Ca2+ overload, depolarisation of membrane potential. Remarkably, 13-OD, B6, A2, and A10-2 induced mitophagy and ferroptosis. In summary, our results reveal that 13-OD, B6, A2, and A10-2 holds great potential in developing anti-tumor agents for targeting TMBIM6.

Euphorbia diterpenoids: isolation, structure, bioactivity, biosynthesis, and synthesis (2013-2021)

Covering: 2013 to 2021As the characteristic metabolites of Euphorbia plants, Euphorbia diterpenoids have always been a hot topic in related science communities due to their intriguing structures and broad bioactivities. In this review, we intent to provide an in-depth and extensive coverage of Euphorbia diterpenoids reported from 2013 to the end of 2021, including 997 new Euphorbia diterpenoids and 78 known ones with latest progress. Multiple aspects will be summarized, including their occurrences, chemical structures, bioactivities, and syntheses, in which the structure-activity relationship and biosynthesis of this class will be discussed for the first time.

Effect of the vinegar-process on chemical compositions and biological activities of Euphorbia kansui: A review

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine (TCM) the root of Euphorbia kansui S.L.Liou ex S.B.Ho (EK), is used for treating edema and ascites but is also of toxicological concerns. And the clinical applications of EK have been seriously restricted for its severe toxicity. To reduce its toxicity, a commonly used clinical practice is processing it with vinegar.

AIM OF THE REVIEW

This review aimed to summarize and discuss updated information on biological activities and phytochemistry of EK before and after vinegar-processing, and provide feasible insights for further research on the chemical composition, toxicity and pharmacological effects of EK before and after vinegar-processing.

MATERIALS AND METHODS

The relevant information on chemical compositions and biological activities of EK before and after vinegar-processing was collected from scientific databases (Google Scholar, PubMed, CNKI, SpringerLink, Web of Science, Wiley Online Library and SciFinder). Additionally, published and unpublished Ph.D. and MSc. dissertations were also obtained from online databases.

RESULTS AND DISCUSSIONS

Diuretic and purgative effect of EK are well documented pharmacologically as are acute, irritant and organic toxic effects. Some of about terpenoids reported have antiproliferative effects on cancer cells and potential antiviral effect. After processing with vinegar, the contents of terpenoids mostly were reduced (ingenane and jatrophane type) with some new compounds being generated (unclear). Also, the toxicity of EK was decreased (using mice, rats and zebrafish embryos model), while the diuretic and purgative effects were retained (using cancerous ascites model rats and mice).

CONCLUSIONS

While some evidence exists for the reduction of toxicity without compromising the pharmacological effects of EK after vinegar processing, the specific mechanism of action remains unknown. Consequently, further research is necessary to investigate the mechanisms and the relationship between vinegar processing and changes in the chemical composition as well as pharmacological effects/toxicity. This is essential before a safe clinical use can be endorsed.

Radix Kansui Stir-Fried with Vinegar Reduces Radix Kansui-Related Hepatotoxicity in Mice via Mitochondrial Pathway

OBJECTIVE

To investigate the mechanism of Radix Kansui (RK) stir-fried with vinegar (VRK) decreased hepatotoxicity in mice.

METHODS

According to a random number table, 40 mice were randomly divided into negative control group (0.5% carboxymethylcellulose sodium, 20 mL/kg), positive control group (0.1% mixture of carbon tetrachloride in soybean oil, 20 mL/kg), RK group (the ethyl acetate extracts of RK, 250 g crude drug/kg) and VRK group (the ethyl acetate extracts of VRK, 250 g crude drug/kg) with 10 mice per group. All mice were administered orally by gavage daily for 7 continuous days. The morphology of liver tissues was examined to assess the liver injury by a transmission electron microscope. Hepatocyte apoptosis in vivo was determined by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nickend labeling (TUNEL) assay. Immunohistochemical technique was adopted to detect the expression of particular antiapoptotic and proapoptotic proteins in the mitochondrial pathways, including B-cell lymphoma (Bcl-2) and caspase-3, as well as the expression of inflammatory mediators, including nuclear factor kappa B (NF- κ B) and intercellular adhesion molecule-1 (ICAM-1).

RESULTS

Liver injury and hepatocyte apoptosis were observed in RK mice, and the liver injury were significantly reduced in VRK-treated mice. In immunohistochemistry study, compared with the negative control group, RK inhibited dramatically the Bcl-2 protein expression and significantly increased the expression of caspase-3, NF- κ B and ICAM-1 (all P<0.01). Compared with the RK group, VRK group induced significant increase on Bcl-2 protein expression, and decreased the caspase-3, NF- κ B and ICAM-1 protein expression (P<0.05 or P<0.01).

CONCLUSION

The mechanism of reduced hepatotoxicity of VRK may be associated with the reduced inflammation, regulation of antiapoptotic and proapoptotic mediators in the mitochondrial pathway.

Marine Streptomyces sp. derived antimycin analogues suppress HeLa cells via depletion HPV E6/E7 mediated by ROS-dependent ubiquitin-proteasome system

Four new antimycin alkaloids (1–4) and six related known analogs (5–10) were isolated from the culture of a marine derived Streptomyces sp. THS-55, and their structures were elucidated by extensive spectroscopic analysis. All of the compounds exhibited potent cytotoxicity in vitro against HPV-transformed HeLa cell line. Among them, compounds 6–7 were derived as natural products for the first time, and compound 5 (NADA) showed the highest potency. NADA inhibited the proliferation, arrested cell cycle distribution, and triggered apoptosis in HeLa cancer cells. Our molecular mechanic studies revealed NADA degraded the levels of E6/E7 oncoproteins through ROS-mediated ubiquitin-dependent proteasome system activation. This is the first report that demonstrates antimycin alkaloids analogue induces the degradation of high-risk HPV E6/E7 oncoproteins and finally induces apoptosis in cervical cancer cells. The present work suggested that these analogues could serve as lead compounds for the development of HPV-infected cervical cancer therapeutic agents, as well as research tools for the study of E6/E7 functions.