Scopadulciol, Isolated from Scoparia dulcis, Induces β-Catenin Degradation and Overcomes Tumor Necrosis Factor-Related Apoptosis Ligand Resistance in AGS Human Gastric Adenocarcinoma Cells

Linderapyrone analogue LPD-01 as a cancer treatment agent by targeting importin7

The Wnt/β-catenin signaling pathway plays important roles in several cancer cells, including cell proliferation and development. We previously succeeded in synthesizing a small molecule compound inhibiting the Wnt/β-catenin signaling pathway, named LPD-01 (1), and 1 inhibited the growth of human colorectal cancer (HT-29) cells. In this study, we revealed that 1 inhibits the growth of HT-29 cells stronger than that of another human colorectal cancer (SW480) cells. Therefore, we have attempted to identify the target proteins of 1 in HT-29 cells. Firstly, we investigated the effect on the expression levels of the Wnt/β-catenin signaling pathway-related proteins. As a result, 1 inhibited the expression of target proteins of Wnt/β-catenin signaling pathway (c-Myc and Survivin) and their genes, whereas the amount of transcriptional co-activator (β-catenin) was not decreased, suggesting that 1 inhibited the Wnt/β-catenin signaling pathway without affecting β-catenin. Next, we investigated the target proteins of 1 using magnetic FG beads. Chemical pull-down assay combined with mass spectrometry suggested that 1 directly binds to importin7. As expected, 1 inhibited the nuclear translocation of importin7 cargoes such as Smad2 and Smad3 in TGF-β-stimulated HT-29 cells. In addition, the knockdown of importin7 by siRNA reduced the expression of target genes of Wnt/β-catenin signaling pathway. These results suggest that importin7 is one of the target proteins of 1 for inhibition of the Wnt/β-catenin signaling pathway.

A New Diterpenoid of Indonesian Scoparia dulcis Linn: Isolation and Cytotoxic Activity against MCF-7 and T47D Cell Lines

Scoparia dulcis Linn plays an important role in treatment because it contains active compounds that are proven to have a variety of activities, including cytotoxicity on various cancer cells. The objective of this study is to isolate and identify the cytotoxic compounds in the ethyl acetate fraction of Scoparia dulcis, observe cell cycle inhibition and induction of apoptosis in vitro, and carry out molecular studies using in silico studies. A new diterpene compound was isolated from the ethyl acetate fraction of Scoparia dulcis L. of Indonesian origin. Chromatographic methods were used to isolate the compound, spectroscopic methods were used to elucidate its structure, and these data were compared with those reported in the literature. The compound was tested for its cytotoxic activity against two breast cancer cells (MCF-7 and T47D). The results of the isolated compound showed a cytotoxic effect on MCF-7 and T47D breast cancer cells at IC50 70.56 ± 1.54 and <3.125 ± 0.43 µg/mL, respectively. The compound inhibited the growth of MCF-7 and T47D breast cancer cells and the accumulation of cells in the G1 phases, and it induced apoptosis. Based on a spectroscopic analysis, the isolated compound was identified as 2α-hydroxyscopadiol, which is a new diterpenoid. A docking study revealed that the isolate's hydroxyl groups are essential for interacting with crucial residues on the active sites of the ER and PR and caspase-9. The isolate inhibits ER and PR activity with binding energies of -8.2 kcal/mol and -7.3 kcal/mol, respectively. In addition, the isolate was also able to induce apoptosis through the activation of the caspase-9 pathway with an affinity of -9.0 kcal/mol. In conclusion, the isolated compound from S. dulcis demonstrated anticancer activity based on in vitro and in silico studies.

Membrane Localization of β-Catenin in Prostate Cancer PC3 Cells Treated with Teucrium persicum Boiss. Extract

Teucrium persicum Boiss. is an Iranian endemic plant which belongs to the Lamiaceae family and has been used to relieve pains in traditional Iranian medicine. We have previously found that treatment of prostate cancer PC3 cells with Teucrium persicum extract leads to the formation of small populations of epithelial cells. β-Catenin is a component of cell adherens junctions in epithelial cells and therefore, in this study, we have investigated the effect of Teucrium persicum extract on expression, cellular localization, and transcriptional activity of β-Catenin protein in PC-3 cells. Indirect immunofluorescence microscopy results showed that the cells treated with T. persicum extract had higher levels of β-Catenin protein at the cell membrane. Western blotting experiments produced consistent results. Gene expression studies by using a few β-Catenin-target genes including c-MYC, CYCLIN D1, and a reporter Luciferase gene under the control of several β-Catenin/TCF binding elements showed that treatment of PC3 cells with the methanolic extract of T. persicum decreases the transcriptional activities of β-Catenin. The results of this study provide further support for the anticancer properties of T. persicum. Definitely, more detailed molecular investigations are needed to find the mechanism(s) behind these effects. Highlightsβ-Catenin protein is a main component of Wnt signaling pathway and adherens junction.Activation of Wnt signaling pathway affects translocation of β-Catenin.Teucrium persicum extract induces β-Catenin localization at cell membrane.Teucrium persicum affects the transcriptional activity of β-Catenin.It stabilizes E-cadherin/β-Catenin protein complex and adherens junction.

Anticancer activity of Nigerian medicinal plants: a review

Background

Cancer is currently the leading cause of death globally and the number of deaths from cancer is on the rise daily. Medicinal plants have been in continuous use over the years for the management of cancer, particularly, in most developing countries of the world including Nigeria. The use of synthetic drugs for the treatment of cancer is often accompanied by toxic side effects. Thus, the alternative use of readily available and inexpensive medicinal plants is the panacea to the toxic side effects associated with synthetic drugs.

Main body

The present review summarized the anticancer activity of 51 medicinal plants that are widespread in all regions of Nigeria. Furthermore, the proposed anticancer pharmacological actions as well as the anticancer bioactive compounds, the type of cancer cell inhibited, the plant parts responsible for the anticancer activity, and the nature of the extracts used for the studies were discussed in this review. The 51 Nigerian medicinal plants were reported to exhibit anticancer activities of the prostate, cervices, lung, skin, colon, esophagus, blood, ovary, central nervous system/brain, breast, stomach, pancreas, larynx, and kidney. The major classes of bioactive compounds indicated to be responsible for the anticancer activity include the polyphenols, flavonoids, alkaloids, saponins, triterpenes, tannins, and quinones. The major anticancer pharmacological actions of these bioactive compounds were antiproliferative, cytotoxic, cytostatic, antimetastatic, apoptotic, and antioxidative as well as provoked cell cycle arrest, inhibition of angiogenesis and reduction of cancer cell viability.

Conclusion

The Nigerian medicinal plants can be harnessed to provide for readily available and inexpensive anticancer drugs in the future because the plants reported in this review showed promising anticancer activity.

Analysis of Gene Expression of miRNA-106b-5p and TRAIL in the Apoptosis Pathway in Gastric Cancer

Helicobacter pylori (H. pylori) is one of the main causes of gastric gancer. TNF-related apoptosis-inducing ligand (TRAIL) is a protein able to promote apoptosis in cancer cells, however not in gastric cancer, which presents resistance to apoptosis via TRAIL. It is believed that MicroRNA-106b-5p might be involved in this resistance, although its role in Gastric Cancer is unclear. We aimed to determine the expression of microRNA-106b-5p and TRAIL in patients with gastric diseases, infected by H. pylori, and understand the relationship between these genes and their role in apoptosis and the gastric cancer pathways. H. pylori was detected by PCR, gene expression analysis was performed by real-time-qPCR, and bioinformatics analysis was performed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Cytoscape software. A total of 244 patients were divided into groups (Control, Gastritis, and Cancer); H. pylori was detected in 42.2% of the samples. The cancer group had a poor expression of TRAIL (p < 0.0001) and overexpression of microRNA-106b-5p (p = 0.0005), however, our results confirmed that these genes are not directly related to each other although both are apoptosis-related regulators. Our results also indicated that H. pylori decreases microRNA-106b-5p expression and that this is a carcinogenic bacterium responsible for gastric diseases.

Isolation and characterization of cytotoxic and anti-inflammatory constituents fromScoparia dulcisL

Scoparia dulcis L. is one of the edible widely distributed Scropholariaceae species in Asia, Africa and America. It is used in the treatment of respiratory and inflammatory diseases, diabetes, hypertension, cancer, hepatitis and tuberculosis. A phytochemical investigation on S. dulcis led to the isolation of two new acyclic diterpenes Acetic acid 6-hydroxy-2-(6-hydroxy-4-methyl-hex-4-enylidene)-4,8-dimethyl-undeca-4,8-dienyl ester (1) and Acetic acid 8-hydroxy-2-(6-hydroxy-4-methyl-hex-4-enylidene)-6,10-dimethyl-undeca-5,9-dienyl ester (2) in addition to eight known compounds (3–10), namely scopadulciol (3), 4- epi-scopadulcic acid B (4), dulcidiol (5), scopadulcic acid B (6), hymenoxin (7), glutinol (8), eupatilin (9) and 5-demethylnobiletin (10). The structures elucidation was performed using spectroscopic means, including 1D and 2D nuclear magnetic resonance and high-resolution electrospray ionization mass spectrum spectrometric analysis. Furthermore, the isolated compounds were investigated for their anti-inflammatory activity through the determination of inhibition of nuclear factor-kappa B activity in human chondrosarcoma (SW1353) cells, the inhibition of inducible nitric oxide synthase mouse macrophages (RAW264.7) and the decrease in cellular oxidative stress in HepG2 cells. Moreover, the cytotoxic activity was investigated against four cancer and two kidney cell lines. Among the isolates, 3, 5 and 10 showed anti-inflammatory activity in terms of inhibiting nuclear factor-kappa B and inducible nitric oxide synthase. Compounds 3–5 were the most cytotoxic towards cancer cell lines (IC50: 3.8 µM to 42.3 µM) followed by 10 (IC50: 30.9- > 64.4 µM). Cytotoxicity of compounds 3–5 was comparable to the activity of doxorubicin.

Screening for natural products that affect Wnt signaling activity

Wnt signaling has been implicated in numerous aspects of development, cell biology, and physiology. When aberrantly activated, Wnt signaling can also lead to the formation of tumors. Thus, Wnt signaling is an attractive target for cancer therapy. Based on our screening program targeting Wnt signaling activity using a cell-based luciferase screening system assessing TCF/β-catenin transcriptional activity, we isolated a series of terpenoids and heterocyclic aromatic compounds that affect the Wnt signaling pathway at different points. Here, we describe our recent results in screening for natural products that inhibit or activate Wnt signaling.

DR5-Cbl-b/c-Cbl-TRAF2 complex inhibits TRAIL-induced apoptosis by promoting TRAF2-mediated polyubiquitination of caspase-8 in gastric cancer cells

Ubiquitination of caspase‐8 regulates TNF‐related apoptosis‐inducing ligand (TRAIL) sensitivity in cancer cells, and the preligand assembly complex plays a role in caspase‐8 polyubiquitination. However, whether such a complex exists in gastric cancer cells and its role in TRAIL‐triggered apoptosis is unclear. In this study, DR5, casitas B‐lineage lymphoma‐b (Cbl‐b)/c‐Cbl, and TRAF2 formed a complex in TRAIL‐resistant gastric cancer cells, and Cbl‐b and c‐Cbl were the critical adaptors linking DR5 and TRAF2. Treatment with TRAIL induced caspase‐8 translocation into the DR5‐Cbl‐b/c‐Cbl‐TRAF2 complex to interact with TRAF2, which then mediated the K48‐linked polyubiquitination of caspase‐8. The proteasome inhibitor bortezomib markedly enriched the p43/41 products of caspase‐8 activated by TRAIL, indicating proteasomal degradation of caspase‐8. Moreover, TRAF2 knockdown prevented the polyubiquitination of caspase‐8 and thus increased TRAIL sensitivity. In addition, the inhibition of Cbl‐b or c‐Cbl expression and overexpression of miR‐141 targeting Cbl‐b and c‐Cbl partially reversed TRAIL resistance by inhibiting the interaction between TRAF2 and caspase‐8 and the subsequent polyubiquitination of caspase‐8. These results indicate that the DR5‐Cbl‐b/c‐Cbl‐TRAF2 complex inhibited TRAIL‐induced apoptosis by promoting TRAF2‐mediated polyubiquitination of caspase‐8 in gastric cancer cells.

Diterpenes and Their Derivatives as Potential Anticancer Agents

As therapeutic tools, diterpenes and their derivatives have gained much attention of the medicinal scientists nowadays. It is due to their pledging and important biological activities. This review congregates the anticancer diterpenes. For this, a search was made with selected keywords in PubMed, Science Direct, Web of Science, Scopus, The American Chemical Society and miscellaneous databases from January 2012 to January 2017 for the published articles. A total 28, 789 published articles were seen. Among them, 240 were included in this study. More than 250 important anticancer diterpenes and their derivatives were seen in the databases, acting in the different pathways. Some of them are already under clinical trials, while others are in the nonclinical and/or pre-clinical trials. In conclusion, diterpenes may be one of the lead molecules in the treatment of cancer. Copyright © 2017 John Wiley & Sons, Ltd.

Elucidation of terpenoid metabolism in Scoparia dulcis by RNA-seq analysis

Scoparia dulcis biosynthesize bioactive diterpenes, such as scopadulcic acid B (SDB), which are known for their unique molecular skeleton. Although the biosynthesis of bioactive diterpenes is catalyzed by a sequence of class II and class I diterpene synthases (diTPSs), the mechanisms underlying this process are yet to be fully identified. To elucidate these biosynthetic machinery, we performed a high-throughput RNA-seq analysis, and de novo assembly of clean reads revealed 46,332 unique transcripts and 40,503 two unigenes. We found diTPSs genes including a putative syn-copalyl diphosphate synthase (SdCPS2) and two kaurene synthase-like (SdKSLs) genes. Besides them, total 79 full-length of cytochrome P450 (CYP450) genes were also discovered. The expression analyses showed selected CYP450s associated with their expression pattern of SdCPS2 and SdKSL1, suggesting that CYP450 candidates involved diterpene modification. SdCPS2 represents the first predicted gene to produce syn-copalyl diphosphate in dicots. In addition, SdKSL1 potentially contributes to the SDB biosynthetic pathway. Therefore, these identified genes associated with diterpene biosynthesis lead to the development of genetic engineering focus on diterpene metabolism in S. dulcis.

New Frontiers in Promoting TRAIL-Mediated Cell Death: Focus on Natural Sensitizers, miRNAs, and Nanotechnological Advancements

Cancer is a multifaceted and genomically complex disease, and rapidly emerging scientific evidence is emphasizing on intra-tumor heterogeneity within subpopulations of tumor cells and rapidly developing resistance against different molecular therapeutics. There is an overwhelmingly increasing list of agents currently being tested for efficacy against cancer. In accordance with the concept that therapeutic agents must have fewer off target effects and considerable efficacy, TRAIL has emerged as one among the most deeply investigated proteins reportedly involved in differential killing of tumor cells. Considerable killing activity of TRAIL against different cancers advocated its entry into clinical trials. However, data obtained through preclinical and cell culture studies are deepening our understanding of wide-ranging mechanisms which induce resistance against TRAIL-based therapeutics. These include downregulation of death receptors, overexpression of oncogenes, inactivation of tumor suppressor genes, imbalance of pro- and anti-apoptotic proteins, and inactivation of intrinsic and extrinsic pathways. Substantial fraction of information has been added into existing pool of knowledge related to TRAIL biology and recently accumulating evidence is adding new layers to regulation of TRAIL-induced apoptosis. Certain hints have emerged underscoring miR135a-3p- and miR-143-mediated regulation of TRAIL-induced apoptosis, and natural agents have shown remarkable efficacy in improving TRAIL-based therapeutics by increasing expression of tumor suppressor miRNAs. In this review, we summarize most recent breakthroughs related to naturopathy and strategies to nanotechnologically deliver TRAIL to the target site in xenografted mice. We also set spotlight on positive and negative regulators of TRAIL-mediated signaling. Comprehensive knowledge of genetics and proteomics of TRAIL-based signaling network obtained from cancer patients of different populations will be helpful in getting a step closer to personalized medicine.

Ursolic acid inhibits proliferation and induces apoptosis by inactivating Wnt/β-catenin signaling in human osteosarcoma cells

Although multiple chemotherapeutic agents have been used for osteosarcoma (OS) treatment, their mechanisms need further study. Ursolic acid (UA), a pentacyclic triterpenoid, can reduce cell proliferation and induce apoptosis in various cancer cells, such as OS. However, the exact mechanism underlying this function remains unclear. In this study, we investigated the anti‑proliferative effect of UA in human OS 143B cells and dissected the possible molecular mechanism underlying this effect. We demonstrated that UA can reduce cell proliferation, induce apoptosis and arrest cell cycle in 143B cells, as well as inhibit OS tumor growth in a mouse xenograft model. Using a luciferase reporter assay, we found that the Wnt/β‑catenin signaling is inhibited by UA in 143B cells. Correspondingly, the expression level and nuclear translocation of β‑catenin are both decreased by UA. Exogenous expression of β‑catenin attenuates the anticancer effect of UA in 143B cells, while knockdown of β‑catenin enhances this effect. UA increases the expression level of p53 in a concentration‑dependent manner, and inhibition of p53 reduces the anticancer effect of UA in 143B cells. Moreover, inhibition of p53 partly reverses the UA‑induced downregulation of β‑catenin, as do the targets of Wnt/β‑catenin signaling, such as c‑Myc and cyclin D1. Our findings indicated that UA can inhibit the proliferation of 143B OS cells through inactivation of Wnt/β-catenin signaling, which may be mediated partly by upregulating the expression of p53.

Ethnomedical research and review of Q'eqchi Maya women's reproductive health in the Lake Izabal region of Guatemala: Past, present and future prospects

ETHNOPHARMACOLOGICAL RELEVANCE

In Central America, most Maya women use ethnomedicines for all aspects of their reproductive cycle including menstruation, pregnancy and menopause. However, very few of these plants have been documented, collected and tested in appropriate pharmacological assays to determine possible safety and efficacy. The aim of this work was to provide an overview of information on the ethnomedical uses, ethnopharmacology, chemistry and pharmacological research for medicinal plants used for women's reproductive health in Guatemala, with a special emphasis on the Q'eqchi Maya of the Lake Izabal region, to demonstrate therapeutic potential and support future research in the field.

MATERIALS AND METHODS

Reviews of the ethnobotanical, ethnomedical and ethnopharmacological literature were performed for 30 plants collected in the Lake Izabal region of Guatemala and used by the Q'eqchi Maya for treatment of reproductive health issues were performed up to and including July 2015 using multiple databases, library searches for abstracts, books, dissertations, and websites.

RESULTS AND CONCLUSIONS

Review of the published research confirms that many of the plants used by Q'eqchi Maya women for the management of reproductive health issues have pharmacological activities, including analgesic, anti-inflammatory, estrogenic, progestagenic and/or serotonergic effects, that support the use of these plants and provide plausible mechanisms of action for their traditional uses. Furthermore, a new serotonin agonist, 9, 10-methylenedioxy-5, 6-Z-fadyenolide was isolated, thereby demonstrating an untapped potential for drug discovery. However, to date much of the pharmacological assays have been in vitro only, and few in vivo studies have been performed. Considering the large percentage of the Maya population in Guatemala that use traditional medicines, there remains a significant lack of pharmacological and toxicological data for these plants. Future research should focus on the safety and efficacy of medicinal plants using in vivo preclinical studies and clinical trials, as well as chemical analysis. Since medicinal plants from the Piperaceae are most commonly used as traditional medicines by the Q'eqchi Maya women, and new bioactive compounds have been identified from Piper species, investigations of commonly used plants from this family would be an appropriate place to start. Data generated from such studies would contribute to Guatemala's national effort to promote a complementary relationship between traditional Maya medicine and public health services.

Diterpenoids of terrestrial origin

This review covers the isolation and chemistry of diterpenoids from terrestrial as opposed to marine sources and includes labdanes, clerodanes, pimaranes, abietanes, kauranes, cembranes and their cyclization products. The literature from January to December, 2015 is reviewed.

Natural compounds with Wnt signal modulating activity

This article highlights natural compounds that are reported to modulate the Wnt signalling activity. The plausible mechanisms of action of the natural Wnt modulators are also presented.