Verbascoside promotes apoptosis by regulating HIPK2-p53 signaling in human colorectal cancer

Upregulated lncRNA PRNT promotes progression and oxaliplatin resistance of colorectal cancer cells by regulating HIPK2 transcription

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer and a significant cause of cancer-related mortality globally. Resistance to chemotherapy, especially during CRC treatment, leads to reduced effectiveness of drugs and poor patient outcomes. Long noncoding RNAs (lncRNAs) have been implicated in various pathophysiological processes of tumor cells, including chemotherapy resistance, yet the roles of many lncRNAs in CRC remain unclear.

AIM

To identify and analyze the lncRNAs involved in oxaliplatin resistance in CRC and to understand the underlying molecular mechanisms influencing this resistance.

METHODS

Gene Expression Omnibus datasets GSE42387 and GSE30011 were reanalyzed to identify lncRNAs and mRNAs associated with oxaliplatin resistance. Various bioinformatics tools were employed to elucidate molecular mechanisms. The expression levels of lncRNAs and mRNAs were assessed via quantitative reverse transcription-polymerase chain reaction. Functional assays, including MTT, wound healing, and Transwell, were conducted to investigate the functional implications of lncRNA alterations. Interactions between lncRNAs and transcription factors were examined using RIP and luciferase reporter assays, while Western blotting was used to confirm downstream pathways. Additionally, a xenograft mouse model was utilized to study the in vivo effects of lncRNAs on chemotherapy resistance.

RESULTS

LncRNA prion protein testis specific (PRNT) was found to be upregulated in oxaliplatin-resistant CRC cell lines and negatively correlated with homeodomain interacting protein kinase 2 (HIPK2) expression. PRNT was demonstrated to sponge transcription factor zinc finger protein 184 (ZNF184), which in turn could regulate HIPK2 expression. Altered expression of PRNT influenced CRC cell sensitivity to oxaliplatin, with overexpression leading to decreased sensitivity and decreased expression reducing resistance. Both RIP and luciferase reporter assays indicated that ZNF184 and HIPK2 are targets of PRNT. The PRNT/ZNF184/HIPK2 axis was implicated in promoting CRC progression and oxaliplatin resistance both in vitro and in vivo.

CONCLUSION

The study concludes that PRNT is upregulated in oxaliplatin-resistant CRC cells and modulates the expression of HIPK2 by sponging ZNF184. This regulatory mechanism enhances CRC progression and resistance to oxaliplatin, positioning PRNT as a promising therapeutic target for CRC patients undergoing oxaliplatin-based chemotherapy.

Clerodendrum chinense Stem Extract and Nanoparticles: Effects on Proliferation, Colony Formation, Apoptosis Induction, Cell Cycle Arrest, and Mitochondrial Membrane Potential in Human Breast Adenocarcinoma Breast Cancer Cells

Breast cancer stands out as the most widespread form of cancer globally. In this study, the anticancer activities of Clerodendrum chinense (C. chinense) stem ethanolic extract were investigated. High-performance liquid chromatography (HPLC) analysis identified verbascoside and isoverbascoside as the major bioactive compounds in the C. chinense stem extract. Successfully developed nanoparticles exhibited favorable hydrodynamic diameter, polydispersity index, and surface charge, thus ensuring stability after four months of storage. The total phenolic content and total flavonoid contents in the nanoparticles were reported as 88.62% and 95.26%, respectively. The C. chinense stem extract demonstrated a dose-dependent inhibitory effect on MCF-7, HeLa, A549, and SKOV-3 cancer cell lines, with IC50 values of 109.2, 155.6, 206.9, and 423 µg/mL, respectively. C. chinense extract and NPs exhibited dose-dependent cytotoxicity and the highest selectivity index values against MCF-7 cells. A dose-dependent reduction in the colony formation of MCF-7 cells was observed following treatment with the extract and nanoparticles. The extract induced cytotoxicity in MCF-7 cells through apoptosis and necrosis. C. chinense stem extract and nanoparticles decreased mitochondrial membrane potential (MMP) and induced G0/G1 phase arrest in MCF-7 cells. In conclusion, use of C. chinense stem extract and nanoparticles may serve as a potential therapeutic approach for breast cancer, thus warranting further exploration.

HMGB1-induced activation of ER stress contributes to pulmonary artery hypertension in vitro and in vivo

BACKGROUND

HMGB1 and ER stress have been considered to participate in the progression of pulmonary artery hypertension (PAH). However, the molecular mechanism underlying HMGB1 and ER stress in PAH remains unclear. This study aims to explore whether HMGB1 induces pulmonary artery smooth muscle cells (PASMCs) functions and pulmonary artery remodeling through ER stress activation.

METHODS

Primary cultured PASMCs and monocrotaline (MCT)-induced PAH rats were applied in this study. Cell proliferation and migration were determined by CCK-8, EdU and transwell assay. Western blotting was conducted to detect the protein levels of protein kinase RNA-like endoplasmic reticulum kinase (PERK), activating transcription factor-4 (ATF4), seven in absentia homolog 2 (SIAH2) and homeodomain interacting protein kinase 2 (HIPK2). Hemodynamic measurements, immunohistochemistry staining, hematoxylin and eosin staining were used to evaluate the development of PAH. The ultrastructure of ER was observed by transmission electron microscopy.

RESULTS

In primary cultured PASMCs, HMGB1 reduced HIPK2 expression through upregulation of ER stress-related proteins (PERK and ATF4) and subsequently increased SIAH2 expression, which ultimately led to PASMC proliferation and migration. In MCT-induced PAH rats, interfering with HMGB1 by glycyrrhizin, suppression of ER stress by 4-phenylbutyric acid or targeting SIAH2 by vitamin K3 attenuated the development of PAH. Additionally, tetramethylpyrazine (TMP), as a component of traditional Chinese herbal medicine, reversed hemodynamic deterioration and vascular remodeling by targeting PERK/ATF4/SIAH2/HIPK2 axis.

CONCLUSIONS

The present study provides a novel insight to understand the pathogenesis of PAH and suggests that targeting HMGB1/PERK/ATF4/SIAH2/HIPK2 cascade might have potential therapeutic value for the prevention and treatment of PAH.

The total polyphenolic glycoside extract of Lamiophlomis rotata ameliorates hepatic fibrosis through apoptosis by TGF-β/Smad signaling pathway

BACKGROUND

Hepatic fibrosis is characterized by the excessive deposition of extracellular matrix (ECM) which is mainly secreted by activated hepatic stellate cells (HSCs). Lamiophlomis rotata (L. rotata) was recorded to treat jaundice in the traditional Tibetan medical system with the potential of hepatoprotection. However, the bioactivities and the possible mechanism of L. rotata on hepatic fibrosis is still largely unknown.

AIM OF THE STUDY

To investigate the anti-hepatic fibrosis effects of bioactivities in L. rotata and the probable mechanism of action.

MATERIALS AND METHODS

Herein, total polyphenolic glycosides of L. rotata (TPLR) was purified with the selectivity adsorption resin and was analyzed by ultrahigh-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-Q/TOF/MSⁿ). The anti-hepatic fibrosis effect of TPLR was evaluated by carbon tetrachloride (CCl₄)-induced liver fibrosis, and was evaluated with the apoptosis of activated HSCs.

RESULTS

In total, sixteen compounds, including nine phenylpropanoids and six flavonoids, were identified in the UPLC-TOF-MSⁿ profile of the extracts. TPLR significantly ameliorated hepatic fibrosis in CCl₄-induced mice and inhibited HSCs proliferation, Moreover, TPLR notably increased the apoptosis of activated HSCs along with up-regulated caspase-3, -8, -9, and -10. Furthermore, TPLR inhibited TGF-β/Smad pathway ameliorating hepatic fibrosis though downregulation the expression of Smad2/3, Smad4, and upregulation the expression of Smad7 in vivo and in vitro. Simultaneously, the expression of fibronectin (FN), α-smooth muscle actin (α-SMA), and Collagen I (Col1α1) were decreased in tissues and in cells with TPLR administration.

CONCLUSION

These results initially demonstrated that TPLR has the potential to ameliorate hepatic fibrosis through an apoptosis mechanism via TGF-β/Smad signaling pathway.

Phenolic Phytochemicals for Prevention and Treatment of Colorectal Cancer: A Critical Evaluation of In Vivo Studies

Colorectal cancer (CRC) is the third most diagnosed and second leading cause of cancer-related death worldwide. Limitations with existing treatment regimens have demanded the search for better treatment options. Different phytochemicals with promising anti-CRC activities have been reported, with the molecular mechanism of actions still emerging. This review aims to summarize recent progress on the study of natural phenolic compounds in ameliorating CRC using in vivo models. This review followed the guidelines of the Preferred Reporting Items for Systematic Reporting and Meta-Analysis. Information on the relevant topic was gathered by searching the PubMed, Scopus, ScienceDirect, and Web of Science databases using keywords, such as "colorectal cancer" AND "phenolic compounds", "colorectal cancer" AND "polyphenol", "colorectal cancer" AND "phenolic acids", "colorectal cancer" AND "flavonoids", "colorectal cancer" AND "stilbene", and "colorectal cancer" AND "lignan" from the reputed peer-reviewed journals published over the last 20 years. Publications that incorporated in vivo experimental designs and produced statistically significant results were considered for this review. Many of these polyphenols demonstrate anti-CRC activities by inhibiting key cellular factors. This inhibition has been demonstrated by antiapoptotic effects, antiproliferative effects, or by upregulating factors responsible for cell cycle arrest or cell death in various in vivo CRC models. Numerous studies from independent laboratories have highlighted different plant phenolic compounds for their anti-CRC activities. While promising anti-CRC activity in many of these agents has created interest in this area, in-depth mechanistic and well-designed clinical studies are needed to support the therapeutic use of these compounds for the prevention and treatment of CRC.

Phytochemicals, Biological Activities, Molecular Mechanisms, and Future Prospects of Plantago asiatica L

Plantago asiatica L. has been used as a vegetable and nutritious food in Asia for thousands of years. According to recent phytochemical and pharmacological research, the active compositions of the plant contribute to various health benefits, such as antioxidant, anti-inflammatory, antibacterial, antiviral, and anticancer. This article reviews the 87 components of the plant and their structures, as well as their biological activities and molecular research progress, in detail. This review provides valuable reference material for further study, production, and application of P. asiatica, as well as its components in functional foods and therapeutic agents.

HIPK2 in cancer biology and therapy: Recent findings and future perspectives

Homeodomain-interacting protein kinase 2 (HIPK2) is a serine-threonine kinase that phosphorylates and regulates a plethora of transcriptional regulators and chromatin modifiers. The heterogeneity of its interactome allows HIPK2 to modulate several cellular processes and signaling pathways, ultimately regulating cell fate and proliferation. Because of its p53-dependent pro-apoptotic activity and its downregulation in many tumor types, HIPK2 is traditionally considered a bone fide tumor suppressor gene. However, recent findings revealed that the role of HIPK2 in the pathogenesis of cancer is much more complex, ranging from tumor suppressive to oncogenic, strongly depending on the cellular context. Here, we review the very recent data emerged in the last years about the involvement of HIPK2 in cancer biology and therapy, highlighting the various alterations of this kinase (downregulation, upregulation, mutations and/or delocalization) in dependence on the cancer types. In addition, we discuss the recent advancement in the understanding the tumor suppressive and oncogenic functions of HIPK2, its role in establishing the response to cancer therapies, and its regulation by cancer-associated microRNAs. All these data strengthen the idea that HIPK2 is a key player in many types of cancer; therefore, it could represent an important prognostic marker, a factor to predict therapy response, and even a therapeutic target itself.

miR-4653-3p overexpression is associated with a poor prognosis of pancreatic ductal adenocarcinoma via HIPK2 downregulation

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignant tumor. Several upregulated and downregulated microRNAs (miRNAs) are associated with invasiveness, tumorigenesis, and prognosis of PDAC. Herein, using in situ hybridization, we evaluated miR-4653-3p expression and pancreatic intraepithelial neoplasia (PanIN) and the association between miR-4653-3p expression and clinicopathological factors in PDAC patients. The miR-4653-3p target was also identified. Ninety PDAC cases, including 30 each with normal pancreatic ducts, low-grade PanINs, and high-grade PanINs, were evaluated. miR-4653-3p expression increased in the order-normal pancreatic duct, low-grade PanIN, high-grade PanIN, and PDAC-with no expression detected in normal pancreatic duct. High expression significantly correlated with advanced pathological T stage, lymph node metastasis, advanced Union for International Cancer Control stage, perineural invasion, venous involvement, and shorter overall and disease-specific survival. Homeodomain Interacting Protein Kinase 2 (HIPK2) was identified as a miR-4653-3p target based on mRNA microarray analysis and database screening. In MIA PaCa-2 cells, miR-4653-3p significantly downregulated HIPK2 expression. HIPK2 expression, unlike that of miR-4653-3p, decreased in the order-normal pancreatic duct, low-grade PanIN, high-grade PanIN, and PDAC. Low HIPK2 expression was associated with shorter overall and disease-specific survival in PDAC patients. Thus, miR-4653-3p associates with tumorigenesis and worse prognosis, partly by reducing HIPK2 expression.

Duranta erecta Linn: A critical review on phytochemistry, traditional uses, pharmacology, and toxicity from phytopharmaceutical perspective

ETHNOPHARMACOLOGICAL RELEVANCE

Duranta erecta Linn. belonging to the Verbenaceae family is widely used in the traditional systems of medicines practiced in Bangladesh, India, Nigeria, the Philippines, and Brazil. The ethnomedicinal application as vermifuge, febrifuge, diuretic, anti-parasitic, and anti-malarial are well documented. D. erecta is also a significant source of phenylethanoid glycoside known as acteoside-a drug in clinical trials for IgA nephropathy patients.

AIM OF THIS REVIEW

This review aims to critically highlight the existing studies on D. erecta, including its botanical authentication, geographical distribution, ethnomedicinal uses, phytochemistry, and pharmacological properties. Critical discussion is focused on the overview and gap in knowledge for future research. Additionally, the clinical significance of its major secondary metabolite, i.e., acteoside, has also been discussed with emphasis on biosynthesis, distribution, pre-clinical, and clinical outcomes.

MATERIALS AND METHODS

Professional research data from 1963 to 2021 appeared in scholarly journals, and books were retrieved from scientific database platforms viz. Sci-Finder, PubMed, CNKI, Science Direct, Web of Science, Wiley, Google Scholar, Taylor and Francis, Springer, and Scopus. The chemical structures for all the phytomolecules were validated using Sci-finder and first-hand references. While plant name and synonyms were corroborated by "The Plant List" (www.theplantlist.org).

RESULTS

D. erecta and its key metabolite acteoside display various biological actions like antimalarial, antimicrobial, antioxidant, anticancer, antinephritic, hepatoprotective, neuroprotective, and antiviral properties. Acteoside literature analysis shows its presence in different stages of clinical trials for anti-nephritic, hepatoprotective, and osteoarthritic activity. The phytochemical review of D. erecta exhibited 64 compounds that have been isolated and identified from D. erecta, such as iridoid glycosides, phenylethanoid glycosides, flavonoids, steroids, phenolics, terpenoids, and saponins. The other significant secondary metabolites responsible for its medicinal properties are acteoside, durantol, pectolinaringenin, repenins, scutellarein, and repennoside.

CONCLUSION

Duranta erecta is one of the Verbenaceae plants, widely used in ethnomedicines having various phytochemicals with understandable pharmacological actions mainly confined at the crude extract level. However, further bioactivity-guided or fingerprint-assisted studies are required to validate the ethnomedicinal uses, concerning cellular and molecular mechanisms, quality standardization, and safety with respect to its bioactive constituent(s). Therefore, the present review identified the gap in the research on scientific validation of Duranta based ethnomedicines and may provide critical information for the development of phytopharmaceuticals/Phyto-cosmeceuticals.

The pharmacokinetic property and pharmacological activity of acteoside: A review

Acteoside (AC), a phenylpropanoid glycoside isolated from many dicotyledonous plants, has been demonstrated various pharmacological activities, including anti-oxidation, anti-inflammation, anti-cancer, neuroprotection, cardiovascular protection, anti-diabetes, bone and cartilage protection, hepatoprotection, and anti-microorganism. However, AC has a poor bioavailability, which can be potentially improved by different strategies. The health-promoting characteristics of AC can be attributed to its mediation in many signaling pathways, such as MAPK, NF-κB, PI3K/AKT, TGFβ/Smad, and AMPK/mTOR. Interestingly, docking simulation study indicates that AC can be an effective candidate to inhibit the activity of SARS-CoV2 main protease and protect against COVID-19. Many clinical trials for AC have been investigated, and it shows great potentials in drug development.

Transforming growth factor-beta (TGF-β) in prostate cancer: A dual function mediator?

Transforming growth factor-beta (TGF-β) is a member of a family of secreted cytokines with vital biological functions in cells. The abnormal expression of TGF-β signaling is a common finding in pathological conditions, particularly cancer. Prostate cancer (PCa) is one of the leading causes of death among men. Several genetic and epigenetic alterations can result in PCa development, and govern its progression. The present review attempts to shed some light on the role of TGF-β signaling in PCa. TGF-β signaling can either stimulate or inhibit proliferation and viability of PCa cells, depending on the context. The metastasis of PCa cells is increased by TGF-β signaling via induction of EMT and MMPs. Furthermore, TGF-β signaling can induce drug resistance of PCa cells, and can lead to immune evasion via reducing the anti-tumor activity of cytotoxic T cells and stimulating regulatory T cells. Upstream mediators such as microRNAs and lncRNAs, can regulate TGF-β signaling in PCa. Furthermore, some pharmacological compounds such as thymoquinone and valproic acid can suppress TGF-β signaling for PCa therapy. TGF-β over-expression is associated with poor prognosis in PCa patients. Furthermore, TGF-β up-regulation before prostatectomy is associated with recurrence of PCa. Overall, current review discusses role of TGF-β signaling in proliferation, metastasis and therapy response of PCa cells and in order to improve knowledge towards its regulation, upstream mediators of TGF-β such as non-coding RNAs are described. Finally, TGF-β regulation and its clinical application are discussed.

Verbascoside represses malignant phenotypes of esophageal squamous cell carcinoma cells by inhibiting CDC42 via the HMGB1/RAGE axis

BACKGROUND

As an aggressive human malignancy, esophageal squamous cell carcinoma (ESCC) is prevalent globally, especially in China. Verbascoside (VE) exerts anti-cancer effects in several human cancers. This work was to investigate the effects of VE on ESCC cells.

METHODS

Esophageal squamous cell carcinoma cell proliferation, apoptosis, migration, and invasion were assessed by CCK-8, TUNEL, and Transwell assays. Gene and protein levels were detected by RT-qPCR and western blotting. CDC42 activity was evaluated by G-lisa assay.

RESULTS

Verbascoside significantly inhibited cell proliferation, migration, and invasion and induced cell apoptosis in ESCC cells. Furthermore, it was found that VE markedly inhibited HMGB1 and RAGE expression in a dose-dependent manner. Besides, HMGB1/RAGE upregulation partially reversed the anti-cancer effects of VE on ESCC cells. VE repressed HMGB1/RAGE-induced CDC42 activation in ESCC cells. In addition, ML141-mediated CDC42 inactivation further enhanced the effect of VE on ESCC cell proliferation, apoptosis, migration, and invasion.

CONCLUSIONS

Our findings indicated that VE has significant anti-tumor potential in ESCC by suppressing HMGB1/RAGE-dependent CDC42 activation.

Anticancer effects of acteoside: Mechanistic insights and therapeutic status

Cancer, the uncontrolled proliferation and metastasis of abnormal cells, is a major public health issue worldwide. To date, several natural compounds have been reported with their efficacy in the treatment of different types of cancer. Chemotherapeutic agents are used in cancer treatment and prevention, among other aspects. Acteoside is a phenylethanoid glycoside, first isolated from Verbascum sinuatum, which has demonstrated multiple effects, including antioxidant, anti-epileptic, neuroprotective, anti-inflammatory, antifungal, antihypertensive, and anti-leishmanial properties. This review gathered, analyzed, and summarized the literature on acteoside and its anticancer properties. All the available information about this compound and its role in different types of cancer was collected using different scientific search engines, including PubMed, Scopus, Springer Link, Wiley Online, Web of Science, Scifinder, ScienceDirect, and Google Scholar. Acteoside is found in a variety of plants and has been shown to have anticancer activity in many experimental models through oxidative stress, apoptosis, anti-angiogenesis, anti-invasion, anti-metastasis, synergism with other agents, and anti-proliferative effects through modulation of several pathways. In conclusion, acteoside exhibited potent anticancer activity against different cancer cell lines through modulating several cancer signaling pathways in different non- and pre-clinical experimental models and thus could be a strong candidate for further clinical studies.

The cytotoxicity and apoptotic effects of verbascoside on breast cancer 4T1 cell line

BACKGROUND

Despite significant advancements in breast cancer therapy, novel drugs with lower side effects are still being demanded. In this regard, we investigated the anti-cancer features of verbascoside in 4 T1 mouse mammary tumor cell.

METHODS

First, MTT assay was performed with various concentrations (ranging between 5 to 200 μM) of verbascoside and IC50 was calculated. Then the expression of Bax, Bcl-2, and caspase-3 was evaluated in treated 4 T1 cells. In addition, we investigated the expression of TLR4, MyD88, and NF-κB to ascertain the underlying mechanism of the anti-proliferative feature of verbascoside. Also, flow cytometry followed by double PI and Annexin V was conducted to confirm the apoptosis-inducing effect of verbascoside.

RESULTS

Our results from MTT assay showed verbascoside inhibits proliferation of 4 T1 cancer cells (IC50 117 μM) while is safe for normal HEK293T cells. By qRT-PCR, we observed that verbascoside treatment (100, 117 and, 130 μM) increases the expression of caspase-3 and Bax while reduces the expression of Bcl-2. Also, verbascoside (100, 117 and, 130 μM) increased the expression of TLR4 only at 130 μM dose and the expression of MyD88 whereas reduced the expression of NF-κB at mRNA level. Flow cytometry analysis also confirmed verbascoside induces apoptosis in 4 T1 cells at 117 μM.

CONCLUSION

Taken together, our data showed verbascoside is a safe natural compound for normal cells while has apoptosis-inducing feature through TLR4 axis on 4 T1 cells.

Exercise downregulates HIPK2 and HIPK2 inhibition protects against myocardial infarction

Background

Exercise can protect myocardial infarction (MI) and downregulate cardiac Homeodomain-Interacting Protein Kinase 2 (HIPK2). However, the role of HIPK2 in MI is unclear.

Methods

HIPK2^–/– mice and miR-222^–/– rats, HIPK2 inhibitor (PKI1H) and adeno-associated virus serotype 9 (AAV9) carrying miR-222 were applied in the study. Animals were subjected to running, swimming, acute MI or post-MI remodeling. HIPK2 inhibition and P53 activator were used in neonatal rat cardiomyocytes (NRCMs) and human embryonic stem cell-derived cardiomyocytes (hESC-CMs) subjected to oxygen glucose deprivation/reperfusion (OGD/R). Serum miR-222 levels were analyzed in healthy people and MI patients that were survival or readmitted to the hospital and/or died.

Findings

Cardiac HIPK2 protein levels were reduced by exercise while increased in MI. In vitro, HIPK2 suppression by lentiviral vectors or inhibitor prevented apoptosis induced by OGD/R in NRCMs and hESC-CMs. HIPK2 inhibitor-treated mice and HIPK2^–/– mice reduced infarct size after acute MI, and preserved cardiac function in MI remodeling. Mechanistically, protective effect against apoptosis by HIPK2 suppression was reversed by P53 activators. Furthermore, increasing levels of miR-222, targeting HIPK2, protected post-MI cardiac dysfunction, whereas cardiac dysfunction post-MI was aggravated in miR-222^–/– rats. Moreover, serum miR-222 levels were significantly reduced in MI patients, as well as in MI patients that were readmitted to the hospital and/or died compared to those not.

Interpretation

Exercise-induced HIPK2 suppression attenuates cardiomyocytes apoptosis and protects MI by decreasing P-P53. Inhibition of HIPK2 represents a potential novel therapeutic intervention for MI.

Funding

This work was supported by the grants from National Key Research and Development Project (2018YFE0113500 to JJ Xiao), National Natural Science Foundation of China (82020108002, 81722008, and 81911540486 to JJ Xiao, 81400647 to MJ Xu, 81800265 to YJ Liang), Innovation Program of Shanghai Municipal Education Commission (2017-01-07-00-09-E00042 to JJ Xiao), the grant from Science and Technology Commission of Shanghai Municipality (18410722200 and 17010500100 to JJ Xiao), the “Dawn” Program of Shanghai Education Commission (19SG34 to JJ Xiao), Shanghai Sailing Program (21YF1413200 to QL Zhou). JS is supported by Horizon2020 ERC-2016-COG EVICARE (725229).

Cytotoxic Effects of Verbascoside on MCF-7 and MDA-MB-231

Objectives

Verbascoside, also known as acteoside/kusaginin, has attracted a great attention due to its pharmacological features. In this study, we aimed to determine the cytotoxic effects of pure verbascoside isolated from Phlomis nissolii L. plant in both MCF-7 and MDA-MB-231 cell lines in vitro.

Materials and Methods

MCF-7 and MDA-MB 231 cells were treated with verbascoside (100, 48, 25, 10, 1, 0.5, and 0.1 μM) for 24, 48, and 72 hours. Cytotoxic effect of verbascoside in MCF-7 and MDA-MB-231 cells was assessed using TEBU-BIO cell counting kit 8.

Results and Conclusion

IC₅₀ values for 24, 48, and 72 h verbascoside exposure of MCF-7 cells were determined as 0.127, 0.2174, and 0.2828 μM, respectively. R² values were calculated as 0.9630, 0.8789 and 0.8752, respectively. Two-Way ANOVA multiple comparison test results showed that 100 μM verbascoside has the highest cytotoxic effect on MCF-7 breast cancer (BC) cells after 72 h of exposure. IC₅₀ values for 24, 48 and 72 h verbascoside exposure of MDA-MB 231 cells were determined as 0.1597, 0.2584 and 0.2563 μM, respectively and R² values were calculated as 0.8438, 0.5107 and 0.9203, respectively. Two-Way ANOVA multiple comparisons test results showed that 100 μM verbascoside has the highest cytotoxic effect on MDA-MB 231 BC cells after 24, 48 and 72 h of exposure.

Inhibitory activity of acteoside in melanoma via regulation of the ERβ-Ras/Raf1-STAT3 pathway

BACKGROUND

Melanoma is an aggressive cancer with a rapidly increasing incidence rate worldwide. Acteoside has been shown to have antitumor effects in multiple human cancers; however, the underlying function and mechanisms of acteoside in melanoma remain unclear.

PURPOSE

This study explored the inhibitory effect of acteoside on melanoma and the possible mechanisms.

METHODS

Acteoside (15 mg/kg, 30 mg/kg) was administered to mice daily for 21 days. ICI182,780 (0.5 mg/kg) was intraperitoneally injected 30 min before acteoside administration three times a week to evaluate whether the effects elicited by acteoside were mediated via the estrogen receptor. Tumor growth and metabolism, cardiac function, ROS and apoptosis levels in the spleen, serum inflammatory factors, and immune cells in the spleen were monitored. STAT3, p-STAT3, CD31, and survivin levels in tumor tissues were measured via immunofluorescence. Ras, Raf1, STAT3, p-STAT3, Bcl-2, Bax, cleaved caspase-3, and cleaved caspase-9 levels in tumor tissues were determined via Western Blotting.

RESULTS

The results showed that acteoside inhibited melanoma growth, alleviated inflammation levels in mice, attenuated ROS and apoptosis levels in the spleen, downregulated the levels of CD31, survivin, Ras, Raf1, p-STAT3, and Bcl-2, and upregulated the levels of ERβ, Bax, cleaved caspase-3, and cleaved caspase-9. Moreover, the effect of acteoside was blocked by ICI182,780.

CONCLUSION

Acteoside may promote the apoptosis of tumor cells by regulating the ERβ-Ras/Raf1-STAT3 signaling axis, thus inhibiting the occurrence and development of melanoma.

Network Pharmacology and Molecular Docking on the Molecular Mechanism of Luo-hua-zi-zhu (LHZZ) Granule in the Prevention and Treatment of Bowel Precancerous Lesions

The Luo-hua-zi-zhu (LHZZ) granule has been widely used for the treatment of colorectal adenoma (CRA), which is a precursor of colorectal cancer (CRC). However, the active components of LUZZ and its mechanism of action against CRA have not yet been elucidated. This study was designed to investigate the effect of LHZZ on CRA and explore its pharmacological mechanisms. First, a total of 24 chemical constituents were identified in the 50% aqueous methanol extract of LHZZ granule based on the mass fragment patterns and mass spectral library using the high resolution UPLC-Q-TOF MS/MS system. Subsequently, based on a network pharmacology study, 16 bioactive compounds and 28 targets of the LHZZ associated with CRA were obtained, forming a compound-target network. Molecular docking tests showed tight docking of these compounds with predicted targeted proteins. The protein–protein interaction (PPI) network identified AKT1, CASP3, TP53 and EGFR as hub targets. The Kyoto Encyclopedia of Genes and Genomes pathway network and pathway-target-compound network revealed that the apoptosis pathway was enriched by multiple signaling pathways and multiple targets, including the hub targets. Finally, the reliability of the core targets was evaluated using molecular docking technology and in vitro studies. Our study indicated that the LHZZ particle has preventive and treatment effect on colorectal adenoma through multi-component, multi-target and multi-pathway.

A Review of Plant Extracts and Plant-Derived Natural Compounds in the Prevention/Treatment of Neonatal Hypoxic-Ischemic Brain Injury

Neonatal hypoxic-ischemic (HI) brain injury is one of the major drawbacks of mortality and causes significant short/long-term neurological dysfunction in newborn infants worldwide. To date, due to multifunctional complex mechanisms of brain injury, there is no well-established effective strategy to completely provide neuroprotection. Although therapeutic hypothermia is the proven treatment for hypoxic-ischemic encephalopathy (HIE), it does not completely chang outcomes in severe forms of HIE. Therefore, there is a critical need for reviewing the effective therapeutic strategies to explore the protective agents and methods. In recent years, it is widely believed that there are neuroprotective possibilities of natural compounds extracted from plants against HIE. These natural agents with the anti-inflammatory, anti-oxidative, anti-apoptotic, and neurofunctional regulatory properties exhibit preventive or therapeutic effects against experimental neonatal HI brain damage. In this study, it was aimed to review the literature in scientific databases that investigate the neuroprotective effects of plant extracts/plant-derived compounds in experimental animal models of neonatal HI brain damage and their possible underlying molecular mechanisms of action.

The Anti-cancer Effect of Olea europaea L. Products: a Review

PURPOSE OF REVIEW

The olive tree (Olea europaea L.) has featured as a significant part of medicinal history, used to treat a variety of ailments within folk medicine. The Mediterranean diet, which is rich in olive products, is testament to Olea europaeas positive effects on health, associated with reduced incidences of cancer and cardiovascular disease. This review aims to summarise the current literature regarding the therapeutic potential of Olea europaea products in cancer, detailing the possible compounds responsible for its chemotherapeutic effects.

RECENT FINDINGS

Much of the existing research has focused on the use of cell culture models of disease, demonstrating Olea europaea extracts, and specific compounds within these extracts, have efficacy in a range of in vitro and in vivo cancer models. The source of Olea europaeas cytotoxicity is yet to be fully defined; however, compounds such as oleuropein and verbascoside have independent cytotoxic effects on animal models of cancer. Initial results from animal models are promising but need to be translated to a clinical setting. Treatments utilising these compounds are likely to be well tolerated and represent a promising direction for future research.

Tumor-derived exosomal microRNA-7-5p enhanced by verbascoside inhibits biological behaviors of glioblastoma in vitro and in vivo

Verbascoside (VB), a glycosylated phenylpropane compound, has been widely used in traditional medicine showing anti-inflammatory and anti-tumor effects in many diseases. The current study aimed to investigate the mechanism underlying the inhibitor effect of VB on glioblastoma (GBM). We isolated and identified the tumor-derived exosomes (TEXs) secreted by GBM cells before and after treatment with VB, after which, we detected expression of microRNA (miR)-7-5p in cells and TEXs by qRT-PCR. Loss- and gain-function assays were conducted to determine the role of miR-7-5p in GBM cells with the proliferation, apoptosis, invasion, migration, and microtubule formation of GBM cells detected. A subcutaneous tumor model and tumor metastasis model of nude mice were established to validate the in vitro findings. We found that VB promoted the expression of miR-7-5p in GBM and transferred miR-7-5p to recipient GBM cells by exosomal delivery. Consequently, miR-7-5p downregulated epidermal growth factor receptor (EGFR) expression to inactivate the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, causing inhibition in the proliferation, migration, invasion, and microtubule formation of GBM cells in vitro, as well as decline in tumor formation and metastasis in vivo. Overall, VB can promote the expression of miR-7-5p in GBM cells and transfer miR-7-5p via exosomes, thereby inhibiting the occurrence of GBM.

Inactivation of homeodomain-interacting protein kinase 2 promotes oral squamous cell carcinoma metastasis through inhibition of P53-dependent E-cadherin expression

Homeodomain-interacting protein kinase 2 (HIPK2), a well-known tumor suppressor, shows contradictory expression patterns in different cancers. This study was undertaken to clarify HIPK2 expression in oral squamous cell carcinoma (OSCC) and to reveal the potential mechanism of HIPK2 involvement in OSCC metastasis. Two hundred and four OSCC tissues, together with paired adjacent normal epithelia, dysplastic epithelia, and lymph node metastasis specimens, were collected to profile HIPK2 expression by immunohistochemical staining. High throughput RNA-sequencing was used to detect the dysregulated signaling pathways in HIPK2-deficient OSCC cells. Transwell assay and lymphatic metastatic orthotopic mouse model assay were undertaken to identify the effect of HIPK2 on tumor invasion. Western blotting and luciferase reporter assay were used to examine the HIPK2/P53/E-cadherin axis in OSCC. Nuclear delocalization of HIPK2 was observed during oral epithelial cancerization progression and was associated with cervical lymph node metastasis and poor outcome. Depletion of HIPK2 promoted tumor cell invasion in vitro and facilitated cervical lymph node metastasis in vivo. According to mRNA-sequencing, pathways closely related to tumor invasion were notably activated. Homeodomain-interacting protein kinase 2 was found to trigger E-cadherin expression by mediating P53, which directly targets the CDH1 (coding E-cadherin) promoter. Restoring P53 expression rescued the E-cadherin suppression induced by HIPK2 deficiency, whereas rescued cytoplasmic HIPK2 expression had no influence on the expression of E-cadherin and cell mobility. Together, nuclear delocalization of HIPK2 might serve as a valuable negative biomarker for poor prognosis of OSCC and lymph node metastasis. The depletion of HIPK2 expression promoted OSCC metastasis by suppressing the P53/E-cadherin axis, which might be a promising target for anticancer therapies.

Biological effects of verbascoside and its anti-inflammatory activity on oral mucositis: a review of the literature

Oral mucositis is among the most common tissue toxicities associated with both cytotoxic cancer regimens and head and neck radiotherapy. Current management of oral mucositis might comprise growth factors and cytokines, anti-inflammatory agents, anesthetics, analgesics, antimicrobial and coating agents, cryotherapy and mucosal protectants. Despite its long history and its impact on patients, there are currently no effective options for the prevention or treatment of mucositis. In recent years, more attention has been focused on the role of natural drugs. Verbascoside belongs to the phenylpropanoid glycosides family. Several biological properties have been described, such as anti-inflammatory, antimicrobial, antitumor and antioxidant. Verbascoside, particularly when in solution with polyvinylpyrrolidone and sodium hyaluronate, thanks to barrier effect, is useful in re-epithelialization and in reducing pain, oral mucositis score, burning and erythema.

Acteoside as a potential therapeutic option for primary hepatocellular carcinoma: a preclinical study

Background

Hepatocellular carcinoma (HCC) is a common malignant tumor with characteristics of poor prognosis, high morbidity and mortality worldwide. In particular, only a few systemic treatment options are available for advanced HCC patients, and include sorafenib and the recently described atezolizumab plus bevacizumab regimen as possible first-line treatments. We here propose acteoside, a phenylethanoid glycoside widely distributed in many medicinal plants as a potential candidate against advanced HCC.

Methods

Cell proliferation, colony formation and migration were analyzed in the three human HCC cell lines BEL7404, HLF and JHH-7. Angiogenesis assay was performed using HUVESs. The BEL7404 or JHH-7 xenograft nude mice model was established to analyze the possible antitumor effects of acteoside. qRT-PCR and western blotting were used to reveal the potential antitumor mechanisms of acteoside.

Results

Acteoside inhibited cell proliferation, colony formation and migration in all the three human HCC cell lines BEL7404, HLF and JHH-7. The prohibition of angiogenesis by acteoside was revealed by the inhibition of tube formation and cell migration of HUVECs. The combination of acteoside and sorafenib produced stronger inhibition of cell colony formation and migration of the HCC cells as well as of angiogenesis of HUVECs. The in vivo antitumor efficacy of acteoside was further demonstrated in BEL7404 or JHH-7 xenograft nude mice model, with an enhancement when combined with sorafenib in inhibiting the growth of JHH-7 xenograft. Further treatment of JHH-7 cells with acteoside revealed an increase in the level of tumor suppressor protein p53 as well as a decrease of kallikrein-related peptidase (KLK1, 2, 4, 9 and 10) gene level with no significant changes of the rest of KLK1–15 genes.

Conclusions

Acteoside exerts an antitumor effect possibly through its up-regulation of p53 levels as well as inhibition of KLK expression and angiogenesis. Acteoside could be useful as an adjunct in the treatment of advanced HCC in the clinic.

Study on the Antibreast Cancer Mechanism and Bioactive Components of Si-Wu-Tang by Cell Type-Specific Molecular Network

Si-Wu-Tang (SWT), a traditional Chinese herbal formula, has shown an effect on antibreast cancer. However, the mechanisms and bioactive components of SWT are still unclear. Fortunately, cell type-specific molecular network has provided an effective method. This study integrated the data of formula components, all types of biomolecules in the human body, and nonexpressed protein in breast cancer cells and constructed the breast cancer cell network and the biological network that SWT acted on the breast cancer-related targets by Entity Grammar System (EGS). Biological network showed 59 bioactive components acting on 15 breast cancer-related targets. The antibreast cancer mechanisms were summarized by enrichment analysis: regulation of cell death, response to hormone stimulation, response to organic substance, regulation of phosphorylation of amino acids, regulation of cell proliferation, regulation of signal transmission, and affection of gland development. In addition, we discovered that verbascoside played the role of antibreast cancer by inhibiting cell proliferation, but there was not a report on this effect. The results of CCK8 and western blot were consistent with the antibreast cancer effect of verbascoside based on biological network. Biological network modeling by EGS and network analysis provide an effective way for uncovering the mechanism and identifying the bioactive components of SWT.

HIPK2 suppresses tumor growth and progression of hepatocellular carcinoma through promoting the degradation of HIF-1α

Aberrant angiogenesis of hepatocellular carcinoma (HCC) leads to tumor growth and local or distant metastasis. Uncovering the underlying mechanisms for the neoangiogenesis of HCC can provide novel potential therapeutic targets in the clinic. Here, we reported that serine/threonine homeodomain-interacting protein kinase 2 (HIPK2) was frequently downregulated in HCC tissues compared with the adjacent normal tissues, and patients with lower HIPK2 protein expression were associated with worse overall survival. Both in vitro and in vivo, HIPK2 inhibited the migration of HCC cells, as well as tumor growth and metastasis in xenograft and orthotopic syngeneic HCC mouse models. Furthermore, HIPK2 inhibited the angiogenesis in HCC tumors. Under the hypoxic condition, HIPK2 knockdown enhanced the angiogenesis and the key regulator, HIF-1α signaling pathway; however, HIPK2 overexpression downregulated the tumoral angiogenesis and HIF-1α signaling. In HCC cells, HIPK2 could directly bind to HIF-1α and stimulate the ubiquitination of HIF-1α for proteasomal degradation. HIF-1α knockout partially rescued the promoting effect of HIPK2 depletion on angiogenesis and tumor growth. In conclusion, the downregulation of HIPK2 could enhance the angiogenesis in HCC through inducing the HIF-1α pathway, and further contribute to tumor growth and metastasis, which may provide a novel therapeutic strategy for HCC.

Verbascoside inhibits progression of glioblastoma cells by promoting Let-7g-5p and down-regulating HMGA2 via Wnt/beta-catenin signalling blockade

Glioblastoma (GBM) continues to show a poor prognosis despite advances in diagnostic and therapeutic approaches. The discovery of reliable prognostic indicators may significantly improve treatment outcome of GBM. In this study, we aimed to explore the function of verbascoside (VB) in GBM and its effects on GBM cell biological processes via let‐7g‐5p and HMGA2. Differentially expressed GBM‐related microRNAs (miRNAs) were initially screened. Different concentrations of VB were applied to U87 and U251 GBM cells, and 50 µmol/L of VB was selected for subsequent experiments. Cells were transfected with let‐7g‐5p inhibitor or mimic, and overexpression of HMGA2 or siRNA against HMGA2 was induced, followed by treatment with VB. The regulatory relationships between VB, let‐7g‐5p, HMGA2 and Wnt/β‐catenin signalling pathway were determined. The results showed that HMGA2 was a direct target gene of let‐7g‐5p. VB treatment or let‐7g‐5p overexpression inhibited HMGA2 expression and the activation of Wnt/β‐catenin signalling pathway, which further inhibited cell viability, invasion, migration, tumour growth and promoted GBM cell apoptosis and autophagy. On the contrary, HMGA2 overexpression promoted cell viability, invasion, migration, tumour growth while inhibiting GBM cell apoptosis and autophagy. We demonstrated that VB inhibits cell viability and promotes cell autophagy in GBM cells by up‐regulating let‐7g‐5p and down‐regulating HMGA2 via Wnt/β‐catenin signalling blockade.

6-O-(3″, 4″-di-O-trans-cinnamoyl)-α-l-rhamnopyranosylcatalpol and verbascoside: Cytotoxicity, cell cycle kinetics, apoptosis, and ROS production evaluation in tumor cells

The aim of this study was to evaluate the impact that 6-O-(3″, 4″-di-O-trans-cinnamoyl)-α- l-rhamnopyranosylcatalpol (Dicinn) and verbascoside (Verb), two compounds simultaneously reported in Verbascum ovalifolium, have on tumor cell viability, apoptosis, cell cycle kinetics, and intracellular reactive oxygen species (ROS) level. At 100 µg/mL and 48 hours incubation time, Dicinn and Verb produced good cytotoxic effects in A549, HT-29, and MCF-7 cells. Dicinn induced cell-cycle arrest at the G₀ /G₁ phase and apoptosis, whereas Verb increased the population of subG₁ cells and cell apoptosis rates. Furthermore, the two compounds exhibited time-dependent ROS generating effects in tumor cells (1-24 hours). Importantly, no cytotoxic effects were induced in nontumor MCF-10A cells by the two compounds up to 100 µg/mL. Overall, the effects exhibited by Verb in tumor cells were more potent, which can be correlated with its structural features, such as the presence of phenolic hydroxyl groups.

Verbascoside suppresses the migration and invasion of human glioblastoma cells via targeting c-Met-mediated epithelial-mesenchymal transition

Verbascoside (VB), a glycosylated phenylpropanoid compound, is derived from the plant Syringa vulgaris (Oleaceae) and has been shown to have antitumor effects in multiple human cancers, including glioblastoma (GBM); however, the underlying mechanism has not been completely elucidated. Epithelial-to-mesenchymal transition (EMT) is the pivotal event in tumor progression. c-Met, a receptor tyrosine kinase, plays an important role in GBM aggressiveness via promoting EMT. The current study aimed to explore whether VB suppresses c-Met-induced EMT and investigated the mechanism of c-Met degradation. We found that VB inhibited GBM cell growth and downregulated c-Met and the EMT markers (snail, vimentin, and zeb1) in vitro and in an orthotopic xenograft mouse model. In addition, overexpressing c-Met in glioblastoma cells abolished the effects of VB on EMT. We also used a microscale thermophoresis (MST) assay to show that VB could directly bind to the c-Met protein, and we showed that VB degraded the c-Met protein via the ubiquitination-proteasome pathway. Our study is the first to identify a new mechanism for the anticancer effects of VB, namely, the inhibition of EMT by directly targeting c-Met; the inhibition of EMT results in c-Met protein degradation through the ubiquitination-proteasome pathway. Our current research indicates that VB is a potential agent to treat GBM via the ubiquitin-mediated degradation of c-Met.

Exosomal miR-1229 derived from colorectal cancer cells promotes angiogenesis by targeting HIPK2

Circulating exosomal microRNAs (exomiR) have been demonstrated to be novel diagnostic biomarkers for various cancers. In this study, we found that circulating exomiR-1229 levels were significantly increased in the serum exosomes of patients with colorectal cancer (CRC) and significantly associated with tumor size, lymphatic metastasis, TNM stage and poor survival. Treatment with siRNA-Drosha, siRNA-ALIX and GW4869 repressed the expression of exomiR-1229 secreted from CRC cells. Both CRC-derived exosomes and exomiR-1229 mimic promoted the tubulogenesis of HUVECs, but transfection with exomiR-1229 inhibitor anta-miR-1229 significantly suppressed tube formation. Subsequently, HIPK2 was identified as a target of exomiR-1229 and responsible for the effect of exomiR-1229 on angiogenesis of HUVECs. ExomiR-1229 inhibited the protein expression of HIPK2, thereby activating VEGF pathway. Finally, anta-miR-1229 effectively inhibited tumor growth and angiogenesis in the nude mouse xenograft model. These results highlighted a novel mechanism of CRC angiogenesis and the biological roles of exomiR-1229.

Drug repositioning in head and neck squamous cell carcinoma: An integrated pathway analysis based on connectivity map and differential gene expression

The severe damage to health and social burden caused by head and neck squamous cell carcinoma (HNSCC) generated an urgent need to develop novel anti-cancer therapy. Currently, drug repositioning has risen in responses to the proper time as an efficient approach to invention of new anti-cancer therapies. In the present study, we aimed to screen candidate drugs for HNSCC by integrating HNSCC-related pathways from differentially expressed genes (DEGs) and drug-affected pathways from connectivity map (CMAP). We also endeavored to unveil the molecular mechanism of HNSCC through creating drug-target network and protein-to-protein (PPI) network of component DEGs in key overlapping pathways. As a result, a total of 401 DEGs were obtained from TCGA and GTEx mRNA-seq data. Taking the intersection part of 27 HNSCC-related Kyoto Encyclopedia of Genes and Genomes pathways and 33 drug-affected pathways, we retained 22 candidate drugs corresponding to two key pathways (cell cycle and p53 signaling pathways) of the five overlapping pathways. Two of the hub genes (PCNA and CCND1) identified from the PPI network of component DEGs in cell cycle and p53 signaling pathways were defined as the critical targets of candidate drugs with increased protein expression in HNSCC tissues, which was reported by the human protein atlas (HPA) database and cBioPortal. Finally, we validated via molecular docking analysis that two drugs with unknown effects in HNSCC: MG-262 and bepridil might perturb the development of HNSCC through targeting PCNA. These candidate drugs possessed broad application prospect as medication for HNSCC.

Plant-derived verbascoside and isoverbascoside regulate Toll-like receptor 2 and 4-driven neutrophils priming and activation

BACKGROUND

Neutrophils have a short live in circulation and accelerate greatly local immune responses via increased granulopoiesis and migration at high numbers to infected or inflamed tissue.

HYPOTHESIS

Since neutrophils produce a variety of factors with destructive and pro-inflammatory potential the regulation of their homeostasis and functions might be eventually beneficial in inflammation-related pathological conditions. Herein we investigated the effect of natural-derived verbascoside (Verb) and its positional isomer isoverbascoside (IsoVerb) on neutrophil functions.

METHODS

We used purified murine bone marrow (BM) neutrophils to study cell responsiveness to priming or activation via Toll-like receptors (TLRs) 2 and 4. The expression of CD11b, chemokine (CXC motif) receptor 2 (CXCR2), the intracellular level of phosphorylated p38 mitogen-activated protein kinase (MAPK) and tumor necrosis factor (TNF)-α in neutrophils were determined by flow cytometry while the release of macrophage inflammatory protein (MIP)-2 in culture supernatant was determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

We found that Verb appeared less powerful inhibitor of TLR2 and TLR4-mediated apoptosis than IsoVerb. However at concentrations below 16 µM and in LPS priming conditions Verb was more selective inhibitor of CD11b and CXCR2 expression than IsoVerb. Both compounds showed similar activity on integrin/chemokine receptor expression when neutrophils were stimulated with ZY or were activated with LPS. Verb sustained CXCR2 expression and turnover via regulation of the cell responsiveness to its ligand KC (CXCL1) and via the release of MIP-2 (CXCL2). Both Verb and IsoVerb increased TNF-α production and inhibited p38 phosphorylation in TNF-α⁺ cells. We fail to discriminate sharply between Verb's and IsoVerb's efficacy when studying p38 phosphorylation in LPS stimulated neutrophils. The multi-parametric analysis provides critical insight on the range of on-target effects of Verb and IsoVerb.

CONCLUSION

The strength and selectivity of Verb and IsoVerb depended on the degree of activation and functional state of neutrophils, and both compounds are with potential to affect neutrophil-related pathologies/conditions in heterogenic populations.

Fixed oil from seeds of narrow-leaved ash (F. angustifolia subsp. angustifolia): Chemical profile, antioxidant and antiproliferative activities

Fraxinus angustifolia subsp. angustifolia is a plant with an age-old use for the production of manna. However, it is also a valuable source of fixed oil rich-seeds. In the present study we examined the chemical and biological properties of this oil in order to support a possible application in foodstuffs, nutraceuticals and cosmetics. Fatty acid composition, volatile and phenolic substances were evaluated. Oleic and linoleic acid represented 45.5% and 50.0%, respectively, of the total fatty acid composition. Among polar phenolic substances identified (secoiridoids, phenylethanoid glycosides, phenolic acids and alcohols, flavonoids, coumarins) isoverbascoside is for the first time reported in this species. Volatiles were mainly characterized by sesquiterpenes. The oil showed good antioxidant activity, in terms of ABTS radical scavenging activity, with an IC₅₀ value of 28.2 μg/mL. The antiproliferative activity was also investigated: amelanotic melanoma (C32) and lung carcinoma (A549) cells were the most sensitive with IC₅₀ values comparable to that of the positive control vinblastine. These findings shed light on the potential use of F. angustifolia subsp. angustifolia fixed oil in nutraceutics and cosmetics.

HPLC-DAD-ESI-Q-TOF-MS/MS profiling of Verbascum ovalifolium Donn ex Sims and evaluation of its antioxidant and cytogenotoxic activities

INTRODUCTION

Plant species of Verbascum genus have been intensively investigated in the last decades but most studies focused on evaluation of their biological activities; there are only few studies dealing with their chemical characterisation.

OBJECTIVE

Detailed investigation of the qualitative and quantitative chemical composition, antioxidant and cytogenotoxic activities of a previously non-studied Verbascum species (V. ovalifolium Donn ex Sims).

METHODS

Qualitative analysis of secondary metabolites was performed by HPLC-DAD-ESI-Q-TOF-MS/MS, whereas quantitative data were obtained through HPLC-DAD. Antioxidant activity was evaluated using in vitro assays; cytotoxic and genotoxic effects were assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) and comet assays, respectively.

RESULTS

More than 50 secondary bioactive metabolites belonging to various classes (iridoids, phenylethanoids, flavonoids, phenolic acids) were detected in the methanolic extract of V. ovalifolium and its fractions. The fragmentation pathways of acylated catalpol-type iridoid diglycosides are thoughtfully described herein. The extracts showed good free radical scavenging and ferric ion reducing properties correlated with phenolic, flavonoid, chlorogenic acid and verbascoside contents. Moreover, 24 h treatment of SK-MEL-2 cells with V. ovalifolium extracts produced significant changes in terms of tumour cell viability. The crude extract and the ethyl acetate fraction showed no important signs of cytogenotoxicity in non-tumour cells.

CONCLUSION

The performed phytochemical and biological analyses contribute to the preclinical knowledge about V. ovalifolium and they could help exploiting it in novel herbal medicinal products.

Verbascoside: Identification, Quantification, and Potential Sensitization of Colorectal Cancer Cells to 5-FU by Targeting PI3K/AKT Pathway

Colorectal cancer (CRC) is the third most common cancer mortality worldwide. Although, 5-Fluorouracil (5-FU)-based chemotherapeutic regimens remain the mainstay for treatment of CRC, intrinsic and acquired resistance to 5-FU is the main reason for treatment failure and relapse. Adjunct or add-on therapy, therefore, should be thought of to enhance responsiveness to 5-FU. Verbascoside (VER) is a phenylethanoid glycoside ingredient present in many Plantago species and was widely used in traditional medicine. VER showed antiproliferative effects in many cancer types including CRC. In the present study, VER in Plantago seeds was identified using UPLC-MS/MS and quantified using newly developed and validated UPLC-DAD followed by investigating its potential sensitization of CRC cells to 5-FU in vitro. The potential impact on PI3K/AKT pathway was also investigated. A synergistic cytotoxic interaction between 5-FU and VER besides G1 cell cycle arrest were detected. Enhanced apoptosis mainly by affecting Bax and Bcl-2 and to a lesser extent Bcl-xL and p53 was also observed. Additionally, 5-FU combined to VER was capable of significantly reducing PI3K and p-AKT/total AKT ratio. Overall, these results suggest a potential role of VER as an adjuvant treatment to decrease the resistance of CRC cells to 5-FU possibly by targeting the PI3K/AKT pathway.

Cistanches Herba: An overview of its chemistry, pharmacology, and pharmacokinetics property

ETHNOPHARMACOLOGICAL RELEVANCE

Cistanches Herba is an Orobanchaceae parasitic plant. As a commonly used Traditional Chinese Medicine (TCM), its traditional functions include treating kidney deficiency, impotence, female infertility and senile constipation. Chemical analysis of Cistanches Herba revealed that phenylethanoid glycosides, iridoids, lignans, oligosaccharides, and polysaccharides were the main constituents. Pharmacological studies demonstrated that Cistanches Herba exhibited neuroprotective, immunomodulatory, hormonal balancing, anti-fatigue, anti-inflammatory, hepatoprotection, anti-oxidative, anti-bacterial, anti-viral, and anti-tumor effects, etc. The aim of this review is to provide updated, comprehensive and categorized information on the phytochemistry, pharmacological research and pharmacokinetics studies of the major constituents of Cistanches Herba.

MATERIALS AND METHODS

The literature search was conducted by systematic searching multiple electronic databases including SciFinder, ISI Web of Science, PubMed, Google Scholar and CNKI. Information was also collected from journals, local magazines, books, monographs.

RESULTS

To date, more than 100 compounds have been isolated from this genus, include phenylethanoid glycosides, carbohydrates, lignans, iridoids, etc. The crude extracts and isolated compounds have exhibited a wide range of in vitro and in vivo pharmacologic effects, such as neuroprotective, immunomodulatory, anti-inflammatory, hepatoprotection, anti-oxidative, anti-bacterial, and anti-tumor effects. The phenylethanoid glycosides, echinacoside and acteoside have attracted the most attention for their significantly neuropharmacology effects. Pharmacokinetic studies of echinacoside and acteoside also have also been summarized.

CONCLUSION

Phenylethanoid glycosides have demonstrated wide pharmacological actions and have great clinical value if challenges such as poor bioavailability, fast and extensive metabolism are addressed. Apart from phenylethanoid glycosides, other constituents of Cistanches Herba, their pharmacological activities and underlying mechanisms are also need to be studied further.

Selective cytotoxicity of the herbal substance acteoside against tumor cells and its mechanistic insights

Natural products are characterized by extreme structural diversity and thus they offer a unique source for the identification of novel anti-tumor agents. Herein, we report that the herbal substance acteoside being isolated by advanced phytochemical methods from Lippia citriodora leaves showed enhanced cytotoxicity against metastatic tumor cells; acted in synergy with various cytotoxic agents and it sensitized chemoresistant cancer cells. Acteoside was not toxic in physiological cellular contexts, while it increased oxidative load, affected the activity of proteostatic modules and suppressed matrix metalloproteinases in tumor cell lines. Intraperitoneal or oral (via drinking water) administration of acteoside in a melanoma mouse model upregulated antioxidant responses in the tumors; yet, only intraperitoneal delivery suppressed tumor growth and induced anti-tumor-reactive immune responses. Mass-spectrometry identification/quantitation analyses revealed that intraperitoneal delivery of acteoside resulted in significantly higher, vs. oral administration, concentration of the compound in the plasma and tumors of treated mice, suggesting that its in vivo anti-tumor effect depends on the route of administration and the achieved concentration in the tumor. Finally, molecular modeling studies and enzymatic activity assays showed that acteoside inhibits protein kinase C. Conclusively, acteoside holds promise as a chemical scaffold for the development of novel anti-tumor agents.

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Acteoside was not toxic in physiological cellular or tissue contexts.

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This natural compound modulated antioxidant responses and proteostatic modules.

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Acteoside showed in vitro and in vivo selective cytotoxicity against tumor cells.

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IP administration of acteoside in a mouse tumor model activated immune responses.

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Acteoside inhibited Protein Kinase C.

Cytogenetic tests reveal no toxicity in lymphocytes of rabbit (Oryctolagus cuniculus, 2n=44) feed in presence of verbascoside and/or lycopene

Phenylpropanoid glycosides (PPG), like other phenolic compounds, are a powerful antioxidants and the Verbascoside (VB) is one of the most active of them. A previous study, by using in vitro exposure of blood human lymphocytes to Verbascoside, reported a significant increasings of chromosome fragility compared to control. In the present study, four homogeneous groups of rabbits were used to test in vivo the VB and/or Lycopene (LP) by feeding the animals without VB and LP (control), in presence of VB or/and LP for 80 days. Lymphocyte cell cultures were performed in three different times: 0, 40 and 80 days of the experiment and the cytogenetic tests that we used [CA-test (Chromosome Abnormalities in terms of chromosome and chromatid breaks) and Sister Chromatid Exchange (SCE-test)] have revealed no mutagenic effects on chromosomes. Indeed, mean values/cell of CA and SCE decreased during the experiment with some difference among and within groups, with significant decreasing value only for some group. The study shows clear evidence that diets rich in Verbascoside (and/or Lycopene) do not originate any mutagenic activity, resulting no cytotoxic for the animals and, suggesting a possible their use in both animal and human diets.

Homeodomain-interacting protein kinase 2 (HIPK2): a promising target for anti-cancer therapies

The HIPK2 (serine/threonine homeodomain-interacting protein kinase 2) is a "caretaker" gene, its inactivation increases tumorigenicity while its activation inhibits tumor growth. This report reviews the anti-tumorigenic mechanisms of HIPK2, which include promotion of apoptosis, inhibition of angiogenesis in hypoxia, prevention of tumor invasion/metastasis and attenuation of multidrug resistance in cancer. Additionally, we summarize conditions or factors that may increase HIPK2 activity.

Network pharmacology-based virtual screening of natural products from Clerodendrum species for identification of novel anti-cancer therapeutics

In the present work, latest network pharmacological approach has been used for the screening of natural anticancer compounds from Clerodendrum species.

Development of a High-Throughput Assay for Inhibitors of the Polo-Box Domain of Polo-Like Kinase 1 Based on Time-Resolved Fluorescence Energy Transfer

Although enzyme-linked immunosorbent assay (ELISA) technology has been widely accepted for binding assays against the polo-box domain (PBD) of polo-like kinase-1 (Plk1), these assays have a limitation-related heterogeneous procedure, such as multiple incubations and washing steps to apply high-throughput screenings (HTSs). In the present study, a Plk1-PBD binding assay based on time-resolved fluorescence energy transfer (TR-FRET) was developed for HTS of PBD-binding inhibitors. The TR-FRET-based Plk1-PBD binding assay is sensitive and robust and can be miniaturized into the 384-well plate-based format. Compared with the ELISA-based Plk1-PBD binding assay (Z' factor, 0.53; signal-to-background ratio, 4.19), the TR-FRET-based Plk1-PBD binding assay improved the Z' factor (0.72) and signal-to-background ratio (8.16). Using TR-FRET based Plk1-PBD binding assay, pilot library screening of 1019 natural compounds was conducted and five hit compounds such as haematoxylin, verbascoside, menadione, lithospermic acid and (1,3-dioxolo[4,5-g]isoquinolinium 5,6,7,8-tetrahydro-4-methoxy-6,6-dimethyl-5-[2-oxo-2-(2-pyridinyl)ethyl]-iodide) (DITMD) were identified as Plk1-PBD inhibitor. In a functional assay to validate the hit compounds, five hit compounds exhibited suppression of HeLa cells proliferation. These results suggest that TR-FRET-based Plk1-PBD binding assay can be applied for an efficient and less time-consuming HTS of compound libraries.

Effects of Olive Metabolites on DNA Cleavage Mediated by Human Type II Topoisomerases

Several naturally occurring dietary polyphenols with chemopreventive or anticancer properties are topoisomerase II poisons. To identify additional phytochemicals that enhance topoisomerase II-mediated DNA cleavage, a library of 341 Mediterranean plant extracts was screened for activity against human topoisomerase IIα. An extract from Phillyrea latifolia L., a member of the olive tree family, displayed high activity against the human enzyme. On the basis of previous metabolomics studies, we identified several polyphenols (hydroxytyrosol, oleuropein, verbascoside, tyrosol, and caffeic acid) as potential candidates for topoisomerase II poisons. Of these, hydroxytyrosol, oleuropein, and verbascoside enhanced topoisomerase II-mediated DNA cleavage. The potency of these olive metabolites increased 10–100-fold in the presence of an oxidant. Hydroxytyrosol, oleuropein, and verbascoside displayed hallmark characteristics of covalent topoisomerase II poisons. (1) The activity of the metabolites was abrogated by a reducing agent. (2) Compounds inhibited topoisomerase II activity when they were incubated with the enzyme prior to the addition of DNA. (3) Compounds were unable to poison a topoisomerase IIα construct that lacked the N-terminal domain. Because hydroxytyrosol, oleuropein, and verbascoside are broadly distributed across the olive family, extracts from the leaves, bark, and fruit of 11 olive tree species were tested for activity against human topoisomerase IIα. Several of the extracts enhanced enzyme-mediated DNA cleavage. Finally, a commercial olive leaf supplement and extra virgin olive oils pressed from a variety of Olea europea subspecies enhanced DNA cleavage mediated by topoisomerase IIα. Thus, olive metabolites appear to act as topoisomerase II poisons in complex formulations intended for human dietary consumption.