Anti-metastatic effect of jolkinolide B and the mechanism of activity in breast cancer MDA-MB-231 cells

Jolkinolide B inhibits the progression of hepatocellular carcinoma by regulating Musashi-2 protein

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths. However, the HCC treatment is still challenging. Herein, we aimed to reveal the anti-tumor effect of Jolkinolide B in HCC cell lines Huh-7 and SK-Hep-1. The results showed that Jolkinolide B inhibited the migration, invasion, and epithelial-to-mesenchymal transition(EMT) of HCC cells. In addition, Jolkinolide B induced HCC cell apoptosis by upregulating Bax and downregulating BCL-2 expressions. Furthermore, we demonstrated that Jolkinolide B inactivated the β-catenin signaling and reduced Musashi-2 expression. Finally, we revealed that Musashi-2 overexpression reversed the Jolkinolide B-induced anti-HCC effect. Overall, we proved that Jolkinolide B is a potential candidate for treating HCC.

Ethnomedicinal Uses, Phytochemistry and Pharmacological Properties of Suregada Genus: A Review

Plants of the Suregada Roxb. ex Rottler (formerly Gelonium Roxb. ex Willd) are utilized to treat various ailments, namely, hepatic, gum diseases, pyrexia, eczema, and venereal diseases. This review links the reported compounds to ethnomedicinal uses through pharmacological activities. The compounds possess anticancer, anti-allergic, antibacterial, anti-inflammatory, antioxidant, and anti-HIV properties. From the previous reports, 32 known species of the Suregada genus have been investigated morphologically, and nine were investigated for their phytochemistry and pharmacology. Phytochemistry, ethnomedicinal, and pharmacological uses of the other 23 Suregada species are not known and/or not reported. In this review, abietane diterpenoids are the main compounds expressed by the Suregada, accounting for 71 of the 114 reported compounds. Ten triterpenoids and sterols, one aliphatic, two lignans, five flavonoids, and twenty-one nitrogen-containing compounds have been reported from the genus.

Evaluation of the Anticancer Potential of Morus nigra and Ocimum basilicum Mixture against Different Cancer Cell Lines: An In Vitro Evaluation

Morus nigra (M) and Ocimum basilicum (O) mixture (MO2) extract was extracted using hexane (MO2H), chloroform (MO2C), ethyl acetate (MO2E), and methanol (MO2M) in a Soxhlet apparatus. The cytotoxicity was evaluated using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. The IC50 values of the MO2C-treated cancer cells were 11.31 μg/mL (MDA-MB-231), 15.45 μg/mL (MCF-7), 18.9 μg/mL (HepG2), 26.33 μg/mL (Huh-7), 30.17 μg/mL (LoVo), and 36.76 μg/mL (HCT116). MO2C-treated cells showed cellular and nuclear morphological alterations like chromatin condensation and formation of apoptotic bodies as observed using light and fluorescent microscopy. The antioxidant and anti-inflammatory properties were investigated in vitro using 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and egg albumin denaturation assays. It was evident that the MO2M extract exhibited the highest antioxidant activity (18.13%), followed by the MO2E extract (12.25%), MO2C extract (9.380%), and MO2H extract (6.31%). The highest inhibition percentage of albumin denaturation was observed in MO2H (28.54%), followed by MO2M (4.32%) at 0.2 and 0.1 mg/mL concentrations, respectively. The compounds identified using gas chromatography-mass spectrometry (GC-MS) analysis for MO2C extract were α-trans-bergamotene, germacrene D, selin-4,7(11)-diene, 2 tridecen-1-ol, and 2-decen-1-ol. The present study reveals that MO2C has promising anticancer activity and may serve as a potent polyherbal extract in cancer treatment.

Jolkinolide B: A comprehensive review of its physicochemical properties, analytical methods, synthesis and pharmacological activity

Jolkinolide B is a typical ent-abietane-type diterpenoid, which is first found in Euphorbia jolkini. It is one of the most important active components in many toxic Euphorbia plants. In recent years, jolkinolide B has garnered increasing attention due to its high potent and multiple pharmacological activities. In order to better understand the research status of jolkinolide B, relevant information about jolkinolide B was collected from scientific databases (SciFinder Scholar, PubMed, ACS website, Elsevier, Web of Science, Google Scholar, Science Direct, and CNKI). There are few studies on chemical synthesis and biosynthesis of jolkinolide B. In addition, researchers on the activities of jolkinolide B are mostly concentrated at the cellular level, and there is a lack of research on the mechanism. In this review, the possible applications of jolkinolide B were systematically illustrated for the first time, from plant sources, physicochemical properties, analytical methods, synthesis and pharmacological activities. Jolkinolide B exhibits extensive pharmacological properties, including anticancer, anti-inflammatory, anti-osteoporosis, and anti-tuberculosis activities. Pharmacological activities of jolkinolide B were mainly focused on anticancer and anti-inflammatory activities, and the mechanism of action may be related with inhibition of JAK/STAT pathway, NF-κB pathway and PI3K/Akt/mTOR pathway. In addition, the extraction methods and analytical methods discussed in this review, will facilitate the development of novel herbal products for better healthcare solutions.

Jolkinolide B inhibits proliferation or migration and promotes apoptosis of MCF-7 or BT-474 breast cancer cells by downregulating the PI3K-Akt pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The diterpenoids extracted from Euphorbia kansui S.L. Liou ex S.B.Ho, Euphorbia fischeriana Steud. have good antitumor effects. Jolkinolide B has anti-breast cancer effect, but it is unclear whether it has different therapeutic effects between luminal A subtype and luminal B subtype breast cancer.

AIM OF THE STUDY

This study investigated the Jolkinolide B has different therapeutic, important targets and pathways effects between luminal A subtype and luminal B subtype breast cancer.

MATERIALS AND METHODS

We used bioinformatics to predict the biological process and molecular mechanism of Jolkinolide B in treating two types of breast cancer. Then, in vitro, cultured MCF-7 cells and BT-474 cells were divided into control group, PI3K inhibitor + control group, Jolkinolide B group and PI3K inhibitor + Jolkinolide B group. The CCK-8 assay, Flow cytometric analysis and Transwell cell migration assay was used to detect the cell proliferation, apoptosis, and migration in each group, respectively. ELISA was used to measure the content of Akt and phosphorylated Akt (p-Akt) in cell lysis buffer.

RESULTS

Compared to luminal A breast cancer, Jolkinolide B had more targets, proliferation, migration processes and KEGG pathways when treating luminal B subtype breast cancer. Jolkinolide B significantly prolonged the survival time of luminal B subtype breast cancer patients. Compared to the control group, the cell proliferation absorbance value (A value) and migration number of the two kinds of breast cancer cells in the Jolkinolide B group were decreased (P < 0.01, n = 6), and the number of apoptotic cells was increased (P < 0.01, n = 6). Compared to the Jolkinolide B group, the A value and migration number of the two types of breast cancer cells were significantly decreased in the PI3K inhibitor + Jolkinolide B group (P < 0.01, n = 6), and the number of apoptotic cells was significantly increased (P < 0.01, n = 6). In addition, compared to MCF-7 cells, the A value and migration number of BT-474 cells stimulated with Jolkinolide B were significantly decreased (P < 0.01, n = 6), and the number of apoptotic cells was significantly increased (P < 0.01, n = 6). Akt and p-Akt protein levels in the two breast cancer cell lines in the Jolkinolide B group were all decreased (P < 0.01, n = 6), especially in BT-474 cells stimulated by Jolkinolide B.

CONCLUSION

Jolkinolide B regulates the luminal A and luminal B subtypes of breast cancer through PI3K-Akt, EGFR and other pathways. Jolkinolide B has more significant therapeutic effect on luminal B subtype breast cancer. In vitro, experiments verified that Jolkinolide B significantly inhibited the proliferation and migration activity of BT-474 breast cancer cells by downregulating the PI3K-Akt pathway.

Integrated Strategy of UHPLC-Q-TOF-MS and Molecular Networking for Identification of Diterpenoids from Euphorbia fischeriana Steud. and Prediction of the Anti-Breast-Cancer Mechanism by the Network Pharmacological Method

Breast cancer is one of the most common malignancies in women worldwide. Traditional Chinese medicine has been used as adjunctive or complementary therapy for breast cancer. Diterpenoids from Euphorbia fischeriana Steud. have been demonstrated to possess anti-breast-cancer activity. This research was aimed to systematically explore the diterpenoids from E. fischeriana and study the multiple mechanisms on breast cancer. The structures of diterpenoids were identified by the integrated strategy of UHPLC-Q-TOF-MS and molecular networking. A total of 177 diterpenoids belonging to 13 types were collected. In silico ADME analysis was performed on these compounds. It indicated that 130 of 177 diterpenoids completely adjusted to Lipinski's rule. The targets of compounds were obtained from PharmMapper. The targets of breast cancer were collected from GeneCards. Then, 197 compounds-related targets and 544 breast cancer-related targets were identified. After the intersection process, 58 overlapping targets between compounds-related targets and breast cancer-related targets were acquired. The STRING database was applied to predict the protein-protein interactions. The GO and KEGG pathway enrichment analysis were performed by using the KOBAS database. It indicated that these predicted pathways were closely related to breast cancer. The treatment effect of E. fischeriana on breast cancer might be performed through signaling pathways, such as IL-17 signaling pathway, MAPK signaling pathway, and PI3K-Akt signaling pathway. The predicted top genes such as EGFR, ESR, MAPK, SRC, CASP3, CDK2, and KDR were involved in cell proliferation, gene transcription, apoptosis, signal transduction, DNA damage and repair, tumor differentiation, metastasis, and cell cycle, which indicated that E. fischeriana might treat breast cancer comprehensively. A compounds-KEGG pathways-related targets network was built by using cytoHubba to analyze the hub compounds and targets. It concluded that E. fischeriana treated breast cancer not only by the main components but also by the microconstituents, which reflected the overall regulatory role of multicomponents treating breast cancer. To estimate the binding affinities, binding sites, and binding postures, molecular docking simulations between 177 diterpenoids and top 19 targets were carried out. The results are basically in line with expectations. In conclusion, these results can serve as references for researchers studying potential targets of diterpenoids from E. fischeriana on breast cancer in the future.

Existing knowledge on Euphorbia fischeriana Steud. (Euphorbiaceae): Traditional uses, clinical applications, phytochemistry, pharmacology and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Euphorbia fischeriana Steud. (Euphorbiaceae) is a perennial herb distributed in grassland, hill slopes or gravel hillside, with average altitude of 100-600 m. The whole grass of E. fischeriana is toxic with roots used as folk medicine to treat Zhushui, dyspepsia, abdominal distension, abdominal pain, cough, as well as external applications such as cure of scabies and tuberculosis of lymph nodes.

AIM OF THE REVIEW

This systematic review aims to provide a detailed and in-depth summary about the reported advances in traditional uses, clinical applications, phytochemistry, pharmacology and toxicity of E. fischeriana, so as to offer fresh ideas and broader vision and insights for subsequent studies.

MATERIALS AND METHODS

Various scientific data bases such as CNKI, Elsevier, Google Scholar, Pubmed, Science Direct, SciFinder Scholar and Web of Science were searched to collect information about E. fischeriana. Other relevant literatures were searched in 'Flora of China Editorial Committee', ancient books, Ph.D and Masters' Dissertation to get more data of E. fischeriana.

RESULTS

A total of 241 chemical constituents have been identified from the roots of E. fischeriana, including diterpenoids, triterpenoids, meroterpenoids, acetophenones, flavonoids, coumarins, steroids, phenolic acids, tannins, etc. Various pharmacological activities have been demonstrated, especially anti-tumor, antibacterial, anti-inflammatory, antiviral and anti-leukemia activities. Moreover, different investigations about clinical uses and toxicology of E. fischeriana indicated that attention should be paid to its usage and dosage.

CONCLUSION

The researches of E. fischeriana are excellent, but gap still remains. As a poisonous traditional Chinese medicine, there are not enough studies on the toxicity of E. fischeriana. In addition, scholars' research on the pharmacological mechanism of E. fischeriana focuses more on the anti-tumor activity, which can be broadened in the future. Presumably, chemical constituents and biological activities of diterpenoids and trace meroterpenoids in E. fischeriana deserve further research in-depth in the future, in order to provide low toxicity and high efficiency lead compounds. Meanwhile, further studies on other medicinal aspects may lay a foundation for the comprehensive development and utilization of E. fischeriana.

SOX9 promotes epidermal growth factor receptor-tyrosine kinase inhibitor resistance via targeting β-catenin and epithelial to mesenchymal transition in lung cancer

AIMS

The first-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), gefitinib, continues to be a primary treatment option for lung cancer patients. However, acquisition of resistance to gefitinib is a major obstacle in lung cancer treatment and its cause is poorly understood. The present study aimed to implicate the role of SOX9-β-catenin in developed resistance to gefitinib through epithelial to mesenchymal transition (EMT) in lung cancer in vitro and ex vivo.

MAIN METHODS

Expression effect of SOX9 on survivability of lung cancer patients was demonstrated through online available Kaplan-Meier Plotter data base. Then, cell viability assay, colony forming assay, cell migration and invasion assays, flow cytometry, drug efflux assay, qRT-PCR, and western blotting were conducted to confirmed the role of SOX9 in gefitinib resistance in lung cancer cells. Dual-luciferase assay established the regulatory relation between SOX9 and β-catenin. Multicellular spheroid assay further explored that down regulation of SOX9 could reverse gefitinib resistance ex vivo.

KEY FINDINGS

Kaplan-Meier method correlated the higher expression of SOX9 and β-catenin with poor overall survival of lung cancer patients. Upregulation of SOX9 was associated gefitinib resistance with increased cell proliferation, migration and invasion, single-cell colony-forming ability, reduced apoptosis, and gefitinib intake in lung cancer cells. Moreover, upregulated SOX9 promoted EMT via targeting β-catenin and knockdown of SOX9 reversed the resistance and EMT phenotype. Similarly, we found that multicellular spheroid of gefitinib resistant cells showed larger surface area with more dispersion and viability of cells, while SOX9 knockdown abolished these induced properties ex vivo.

SIGNIFICANCE

SOX9 expression could provide an innovative perspective as biomarker to understand the EGFR-TKIs resistance in lung cancer.

Cucurbitacin B Diminishes Metastatic Behavior of Cholangiocarcinoma Cells by Suppressing Focal Adhesion Kinase

OBJECTIVE

Cholangiocarcinoma (CCA) is a malignant tumor with aggressive metastatic property resulted from dysregulation of metastasis-regulated signaling pathways. The aim of this study was to investigate the effect of cucurbitacin B on metastatic behavior of CCA cells through modulation of focal adhesion kinase (FAK) protein.

METHODS

KKU-452 cells were treated with a specific FAK inhibitor, FAK inhibitor-14, or cucurbitacin B at various concentrations for 24 h. Cell viability was assessed by sulforhodamine B assay. The migratory and invasive abilities of the cells were investigated using wound healing and transwell invasion assays, respectively. The fibronectin-coated plate was used for adhesion assay. The effects of the test compounds on FAK activation and the expression of metastasis-associated proteins were determined by Western blot analysis. The amount of MMP-9 was evaluated using a commercial ELISA Kit.

RESULTS

FAK inhibitor-14 and cucurbitacin B at concentrations which minimally affected KKU-452 cell viability could suppress FAK activation, evidently by decreased level of phospho-FAK protein after exposure to the compound. At these conditions, cucurbitacin B suppressed metastatic behavior including migration, invasion and adhesion abilities of CCA cells similar to FAK inhibitor-14. Further molecular studies demonstrated that FAK inhibitor-14 and cucurbitacin B downregulated the expression of metastasis-associated proteins including MMP-9, ICAM-1 and VEGF. Consequently, exposure to cucurbitacin B inhibited the production of MMP-9 enzyme in CCA cells similar to FAK inhibitor-14 treatment.

CONCLUSION

FAK participated in regulation of metastatic behavior of KKU-452 CCA cells. Cucurbitacin B suppressed FAK activation in the cells which was associated with inhibition of metastasis essential steps and their related metastatic proteins. The compound may be developed as a novel therapeutic agent for CCA metastasis therapy.
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Development of Potential Antitumor Agents from the Scaffolds of Plant-Derived Terpenoid Lactones

Naturally occurring terpenoid lactones and their synthetic derivatives have attracted increasing interest for their promising antitumor activity and potential utilization in the discovery and design of new antitumor agents. In the present perspective article, selected plant-derived five-membered γ-lactones and six-membered δ-lactones that occur with terpenoid scaffolds are reviewed, with their structures, cancer cell line cytotoxicity and in vivo antitumor activity, structure-activity relationships, mechanism of action, and the potential for developing cancer chemotherapeutic agents discussed in each case. The compounds presented include artemisinin (ART, 1), parthenolide (PTL, 2), thapsigargin (TPG, 3), andrographolide (AGL, 4), ginkgolide B (GKL B, 5), jolkinolide B (JKL B, 6), nagilactone E (NGL E, 7), triptolide (TPL, 8), bruceantin (BRC, 9), dichapetalin A (DCT A, 10), and limonin (LMN, 11), and their naturally occurring analogues and synthetic derivatives. It is hoped that this contribution will be supportive of the future development of additional efficacious anticancer agents derived from natural products.

Anticancer properties of Tulbaghia violacea regulate the expression of p53-dependent mechanisms in cancer cell lines

Cancer is an enormous burden of disease globally. Today, more people die from cancer than a combination of several diseases. And in females, breast and cervical malignancies remain the most common types. Currently, cervical and breast cancer are the most diagnosed gynecological cancer type amongst black females in the Southern Sahara while amongst males prostate cancer is on the upward trend. With many of them still dependent on medicinal plants as a form of therapy and the need to identify new therapeutic agents, we have identified a commonly used medicinal plant Tulbaghia violacea Harv. commonly known as Itswele lomlambo (Xhosa), wilde knoffel (Afrikaans) and Isihaqa (zulu) to evaluate its anticancer properties at a molecular biology level. In this study, we evaluated the molecular mechanism of T. violacea extracts in regulating cell death in various cancer cell lines. To achieve this, T. violacea was collected, dried before crushing into a fine ground powder. Three organic solvents namely, methanol, hexane, and butanol at 10 g per 100 mL were used as extraction solvents. Each cell line was treated with varying concentrations of the plant extract to identify the half-maximal inhibitory concentration (IC50). The IC 50 was later used to analyse if the extracts were inducing apoptosis using annexin V analysis. Furthermore, the molecular mechanisms by which apoptosis was induced was analysed by qPCR, western blots. All three extracts exhibited anticancer activity with the most cytotoxic being methanol extract. p53 expression was significantly increased in treated cells that correlated with increased caspase activity. The results point to possible activation of apoptosis following treatment with hexane extracts.

A Nano-Traditional Chinese Medicine Against Lymphoma That Regulates the Level of Reactive Oxygen Species

Jolkinolide B (JB) is a bioactive compound isolated from a Chinese herbal medicine that exerts antitumor activity. However, the anti-lymphoma effect of JB and its mechanism are yet to be revealed. Because free JB has poor pharmacokinetics and weak antitumor efficacy, we opted to use black phosphorus quantum dot (BPQD) nanomaterials as a drug loading platform to synthesize a nano-traditional Chinese medicine (nano-TCM) called BPQDs@JB. Compared with free JB, Raji cells administrated with BPQDs@JB exhibited the cell viability of 19.85 ± 1.02%, and the production of intracellular reactive oxygen species (ROS) was promoted. Likewise, BPQDs@JB was capable of rising the apoptosis rate of Raji cells to 34.98 ± 1.76%. In nude mice transplanted tumor model administrated with BPQDs@JB, the tumor tissue sections administrated with BPQDS@JB achieved a conspicuous red fluorescence, demonstrating the presence of most ROS production in the BPQDS@JB. TUNEL achieved a number of positive (brown) nuclei in vivo, revealing that BPQDS@JB could significantly induce tumor tissue apoptosis. As revealed from the mentioned results, BPQDs@JB can generate considerable ROS and interfere with the redox state to inhibit tumor. In brief, BPQDs@JB may be adopted as a treatment option for lymphoma.

The effect of Euphorbia szovitsii Fisch. & C.A.Mey extract on the viability and the proliferation of MDA-MB-231 cell line

Some medicinal herbs and compounds are known to target cancer cells, but the success of them as anticancer compounds depends to a large extent on their ability to activate pathways that kill cancer cells by arresting cell cycle and inducing apoptosis. The aim of the present study was to determine the anticancer effects of Euphorbia szovitsii Fisch. & C.A.Mey. on the breast cancer cells to reveal the underlying mechanism of its anti-breast cancer properties. In this experimental study, triple negative breast cancer cell line (MDA-MB-231) was cultivated in RPMI-1640 medium. Hydroalcoholic extract (70:30) of aerial parts of the plant was prepared. The cultured cells were treated with different concentrations (0-1000 μg/ml) of E. szovitsii extract for 24 and 48 h. Toxicity of the extract on MDA-MB-231 cells was examined using MTT (3-[4,5-dimethyl-2-thiazolyl]-2, 5 diphenyl tetrazolium bromide) test. The Annexin V-FITC Apoptosis Detection Kit was used to evaluate apoptosis and necrosis. Flow cytometry technique was employed to differentiate different phases of the cell cycle in the cells. Data were analyzed by GraphPad Prism and SPSS software. After 24 and 48 h, the IC50 values were respectively 76.78 (95% CI = 60.75-97.05; R = 0.8588) and 59.71 (95% CI = 46.25-77.09; R = 0.8543) μg/ml for E. szovitsii The extract exhibited antiproliferative effects against MDA-MB-231 cells in a dose-dependent manner. Annexin V-FITC/PI assay confirmed that the extract was able to induce apoptosis in MDA-MB-231 cells. Moreover, treatment with the extract resulted in cell cycle arrest at G1 phase. Therefore, E. szovitsii could induce apoptosis and cycle arrest in the MDA-MB-231 cell line. It might be a good resource of natural products for producing anti-breast cancer drugs.

A screening of growth inhibitory activity of Iranian medicinal plants on prostate cancer cell lines

BACKGROUND

Prostate cancer has been known as one of the most common malignancy in the men and it is therefore very important to prevent and treat this cancer. In this study, the anticancer effects of 20 species of medicinal plants in Iran, especially those grown in Chaharmahal and Bakhtiari province, were investigated on prostate cancer cell lines to identify potential natural alternatives for the development of prostate cancer anticancer drugs.

METHODS

The plants were gathered from Chaharmahal va Bakhtyari and their aerial parts extracted through maceration method using ethanol 70%. Anti-proliferative activity of extracts on PC-3, DU145 and HDF cell lines was evaluated by MTT assay 48 hours after treatment.

RESULTS

Euphorbia szovitsii Fisch. & C.A.Mey. and Achillea wilhelmsii had anti-proliferative activity more than other plants on PC-3. Also IC50s for Urtica dioica, Euphorbia szovitsii Fisch. & C.A.Mey. and Medicago sativa were lower amount among the examined plants on Du-145.

CONCLUSION

According to our result, Euphorbia szovitsii Fisch. & C.A.Mey., U. dioica and Medicago sativa with good anti-proliferative activity can serve as an effective source of natural products to develop new antiprostate cancer drugs.

Structural Diversity and Biological Activities of Diterpenoids Derived from Euphorbia fischeriana Steud

Diterpenoids are the focus of natural product drug discovery because of their great structural diversity and pronounced biological activities. Euphorbia fischeriana Steud is a Chinese traditional medicinal herb for curing edema, ascites, and cancer. This plant contains rich diterpenoids. Based on the carbon skeleton and substituents, it can be classified into thirteen subtypes: ent-abietane, daphnane, tigliane, ingenane, ent-atisane, ent-rosane, ent-kaurene, ent-kaurane, secotigliane, lathyrane, ent-pimarene, isopimarene and dimeric. In this paper, we reviewed the chemical structures and biological activities of 90 diterpenoids isolated from this medicinal herb. We hope that this work can serve as a reference for further research of these diterpenoids and lay the foundation for drug discovery.

Anti-Cancer Activities of Diterpenoids Derived from Euphorbia fischeriana Steud

Euphorbia fischeriana Steud is an essential oriental folk medicine used for healing cancer, edema and tuberculosis. Recently, its anticancer activitity has attracted more attention. A volume of research has indicated that diterpenoids are the major anticancer active constituents from this medicinal herb. In this review, we aimed to provide a summary of the promising anticancer diterpenoids from this plant; many diterpenoids mentioned in this article are newly discovered diterpenoids. According to the carbon skeleton and substituents, they can be classified into eight subtypes: ent-abietane, daphnane, tigliane, ingenane, ent-atisane, ent-rosane, ent-kaurane, and lathyrane. Futhermore, their key anticancer mechanisms and protein targets of these compounds will be discussed. These natural diterpenoids could provide a reservoir for drug discovery.

Jolkinolide B induces apoptosis of colorectal carcinoma through ROS-ER stress-Ca2+-mitochondria dependent pathway

Colorectal carcinoma (CRC) remains one of the leading causes of death in cancer-related diseases. In this study, we aimed to investigate the anticancer effect of Jolkinolide B (JB), a bioactive diterpenoid component isolated from the dried roots of Euphorbia fischeriana Steud, on CRC cells and its underlying mechanisms. We found that JB suppressed the cell viability and colony formation of CRC cells, HT29 and SW620. Annexin V/PI assay revealed that JB induced apoptosis in CRC cells, which was further confirmed by the increased expression of cleaved-caspase3 and cleaved-PARP. iTRAQ-based quantitative proteomics was performed to identify JB-regulated proteins in CRC cells. Gene Ontology (GO) analysis revealed that these JB-regulated proteins were mainly involved in ER stress response, which was evidenced by the expression of ER stress marker proteins, HSP90, Bip and PDI. Moreover, we found that JB provoked the generation of reactive oxygen species (ROS), and that inhibition of the ROS generation with N-acetyl L-cysteine could reverse the JB-induced apoptosis. Confocal microscopy and flow cytometry showed that JB treatment enhanced intracellular and mitochondrial Ca²⁺ level and JC-1 assay revealed a loss of mitochondrial membrane potential in CRC after JB treatment. The mitochondrial Ca²⁺ uptake and depolarization can be blocked by Ruthenium Red (RuRed), an inhibitor of mitochondrial Ca²⁺ uniporter. Taken together, we demonstrated that JB exerts its anticancer effect by ER stress-Ca²⁺-mitochondria signaling, suggesting the promising chemotherapeutic potential of JB for the treatment of CRC.

Jolkinolide B induces apoptosis and inhibits tumor growth in mouse melanoma B16F10 cells by altering glycolysis

Most cancer cells preferentially rely on glycolysis to produce the energy (adenosine triphosphate, ATP) for growth and proliferation. Emerging evidence demonstrates that the apoptosis in cancer cells could be closely associated with the inhibition of glycolysis. In this study, we have found that jolkinolide B (JB), a bioactive diterpenoid extracted from the root of Euphorbia fischeriana Steud, induced tumor cells apoptosis and decreased the production of ATP and lactic acid in mouse melanoma B16F10 cells. Furthermore, we found that JB downregulated the mRNA expression of glucose transporter genes (Glut1, Glut3 and Glut4) and glycolysis-related kinase genes (Hk2 and Ldha) in B16F10 cells. Moreover, treatment with JB upregulated the mRNA expression of pro-apoptosis genes (Bax), downregulated the mRNA expression of anti-apoptosis genes (Bcl-2, Caspase-3 and Caspase-9), decreased the potential of mitochondrial membrane and increased reactive oxygen species (ROS) levels in B16F10 cells. Finally, intragastric administration of JB suppressed tumor growth and induced tumor apoptosis in mouse xenograft model of murine melanoma B16F10 cells. Taken together, these results suggest that JB could induce apoptosis through the mitochondrial pathway and inhibit tumor growth. The inhibition of glycolysis could play a crucial role in the induction of apoptosis in JB-treated B16F10 cells.