Lupeol inhibits proliferation and induces apoptosis of human pancreatic cancer PCNA-1 cells through AKT/ERK pathways

Bioinformatic analysis of the molecular targets of curcumin in colorectal cancer

Colorectal cancer (CRC) is a major global health concern, with rising incidence and mortality rates. Conventional treatments often come with significant complications, prompting the exploration of natural compounds like curcumin as potential therapeutic agents. Using bioinformatic tools, this study investigated the role of curcumin in CRC treatment. Significant protein interactions between curcumin and target proteins were identified in the STITCH database. Differentially expressed genes (DEGs) associated with CRC were then analyzed from GEO databases. Comparing curcumin targets and CRC-related DEGs, nine significant common targets were identified: DNMT1, PCNA, CCND1, PLAU, MMP3, SOX9, FOXM1, CXCL2, and SERPINB5. Pathway enrichment analyses revealed that curcumin-targeted pathways were primarily related to p53, IL-17, NF-kappa B, TNF, and cell cycle signaling, all crucial in CRC development and progression. Further analyses using DAID and EnrichR algorithms showed that the curcumin targets exhibited greater specificity to bronchial epithelial cells and colorectal adenocarcinoma than other diseases. Analyses via the DSigDB database indicated that curcumin ranks highly among other drugs targeting the identified CRC-related genes. Docking studies revealed favorable binding interactions between curcumin and the key CRC-related proteins, suggesting potential molecular mechanisms by which curcumin may exert its effects. In summary, this study provides bioinformatic and docking evidence that curcumin may exert beneficial effects on CRC by modulating the expression or activity of multiple CRC-susceptibility genes involved in critical signaling pathways. These findings warrant further experimental validation and support the potential of curcumin as a therapeutic agent for CRC.

Molecular pharmacology and therapeutic advances of the pentacyclic triterpene lupeol

BACKGROUND

Plant triterpenoids are major sources of nutraceuticals that provide many health benefits to humans. Lupeol is one of the pentacyclic dietary triterpenoids commonly found in many fruits and vegetables, which is highly investigated for its pharmacological effect and benefit to human health.

PURPOSE

This systematic review critically discussed the potential pharmacological benefits of lupeol and its derivatives as evidenced by various cellular and animal model studies. To gain insight into the pharmacological effects of lupeol, the network pharmacological approach is applied. Pharmacokinetics and recent developments in nanotechnology-based approaches to targeted delivery of lupeol along with its safety use are also discussed.

METHODS

This study is dependent on the systematic and non-exhaustive literature survey for related research articles, papers, and books on the chemistry, pharmacological benefits, pharmacokinetics, and safety of lupeol published between 2011 and 2021. For online materials, the popular academic search engines viz. Google Scholar, PubMed, Science Direct, Scopus, ResearchGate, Springer, as well as official websites were explored with selected keywords.

RESULTS

Lupeol has shown promising benefits in the management of cancer and many other human diseases such as diabetes, obesity, cardiovascular diseases, kidney and liver problems, skin diseases, and neurological disorders. The pharmacological effects of lupeol primarily rely on its capacity to revitalize the cellular antioxidant, anti-inflammatory and anti-apoptotic mechanisms. Network pharmacological approach revealed some prospective molecular targets and pathways and presented some significant information that could help explain the pharmacological effects of lupeol and its derivatives. Despite significant progress in molecular pharmacology, the clinical application of lupeol is limited due to poor bioavailability and insufficient knowledge on its mode of action. Structural modification and nanotechnology-guided targeted delivery of lupeol improve the bioavailability and bioactivity of lupeol.

CONCLUSION

The pentacyclic triterpene lupeol possesses numerous human health-benefiting properties. This review updates current knowledge and critically discusses the pharmacological effects and potential applications of lupeol and its derivatives in human health and diseases. Future studies are needed to evaluate the efficacies of lupeol and its derivatives in the management and pathobiology of human diseases.

Eribulin Mesylate Improves Cisplatin-Induced Cytotoxicity of Triple-Negative Breast Cancer by Extracellular Signal-Regulated Kinase 1/2 Activation

Background and Objectives; Triple-negative breast cancer (TNBC) is associated with poor patient prognosis because of its multiple molecular features. Thus, more effective treatment for TNBC is urgently needed. This study determined the possible involvement of ERK1/2 activation in cisplatin-induced cytotoxicity in TNBC by providing additional eribulin treatment. Materials and Methods; We investigated cell viability and apoptosis caused by eribulin, cisplatin, or co-treatment in HCC38, MDA-MB-231, and SKBR3 human breast cancer cells. Results; Cisplatin significantly lowered cell viability and caused high apoptotic cell death in all breast cancer cell lines. The viability of TNBC cells was significantly lower in the group co-treated with cisplatin and eribulin than in the cisplatin-only treatment group. Additional eribulin treatment significantly enhanced PARP cleavage and caspase-3 activity in cisplatin-treated TNBC cells. Moreover, cisplatin treatment activated ERK1/2 in all breast cancer cell lines. The cisplatin and eribulin combination synergistically activated ERK1/2 in TNBC cells compared with the cisplatin-only treatment. Administration of the ERK1/2 inhibitor PD98059 increased the viability of TNBC cells treated with cisplatin plus eribulin. Conclusions; Eribulin could synergize the cytotoxic and apoptotic activities of cisplatin and increase ERK1/2 activation, thus enhancing anti-cancer effects against TNBC cells.

Herbals and Plants in the Treatment of Pancreatic Cancer: A Systematic Review of Experimental and Clinical Studies

Background: Pancreatic cancer represents the most lethal malignancy among all digestive cancers. Despite the therapeutic advances achieved during recent years, the prognosis of this neoplasm remains disappointing. An enormous amount of experimental (mainly) and clinical research has recently emerged referring to the effectiveness of various plants administered either alone or in combination with chemotherapeutic agents. Apart from Asian countries, the use of these plants and herbals in the treatment of digestive cancer is also increasing in a number of Western countries as well. The aim of this study is to review the available literature regarding the efficacy of plants and herbals in pancreatic cancer. Methods: The authors have reviewed all the experimental and clinical studies published in Medline and Embase, up to June 2021. Results: More than 100 plants and herbals were thoroughly investigated. Favorable effects concerning the inhibition of cancer cell lines in the experimental studies and a favorable clinical outcome after combining various plants with established chemotherapeutic agents were observed. These herbals and plants exerted their activity against pancreatic cancer via a number of mechanisms. The number and severity of side-effects are generally of a mild degree. Conclusion: A quite high number of clinical and experimental studies confirmed the beneficial effect of many plants and herbals in pancreatic cancer. More large, double-blind clinical studies assessing these natural products, either alone or in combination with chemotherapeutic agents should be conducted.

A pharmacognostic approach for mitigating pancreatic cancer: emphasis on herbal extracts and phytoconstituents

Background

Pancreatic cancer is studied as one of the most lethal cancers with currently no control of its lethality, mainly due to its late diagnosis and lack of foolproof treatment processes. Despite continuous efforts being made in looking for therapies to deal with cancer, it keeps on being a labyrinth for the researchers. Efforts like discovering new treatment options, repurposing existing drugs, are continuously made to deal with this cancer.

Main body

With the urge to get answers and the fact that nature has all roots of therapeutics, efforts are made in the direction of finding those answers for providing ministrations for pancreatic cancer from plant products. Plant products are used as treatment options either directly in the form of extracts or an alternative to them is individual phytochemicals that are either isolated from the plants or are commercially synthesized for various purposes. In this review, we put forward such pharmacognostic initiatives made in combating pancreatic cancer, focusing mainly on plant extracts and various phytochemicals; along with the mechanisms which they triggered to fulfill the need for cytotoxicity to pancreatic cancer cells (in vitro and in vivo).

Conclusion

This study will thus provide insights into new combination therapy that can be used and also give a clue on which plant product and phytoconstituent can be used in dealing with pancreatic cancer.

Graphical abstract

Function of selected natural antidiabetic compounds with potential against cancer via modulation of the PI3K/AKT/mTOR cascade

Diabetes mellitus (DM) is a metabolic disorder with growing global incidence, as 387 million people were diagnosed in 2014 with an expected projection of 642 million in 2040. Several complications are associated with DM including heart attack, stroke, kidney failure, blindness, and cancer. The latter is the second leading cause of death worldwide accounting for one in every six deaths, with liver, pancreas, and endometrium cancers are the most abundant among patients with diabetes. Phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway plays a vital role in developing a wide array of pathological disorders, among them diabetes and cancer. Natural secondary metabolites that counteract the deleterious effects of reactive oxygen species (ROS) and modulate PI3K/Akt/mTOR pathway could be a promising approach in cancer therapy. Here, 717 medicinal plants with antidiabetic activities were highlighted along with 357 bioactive compounds responsible for the antidiabetic activity. Also, 43 individual plant compounds with potential antidiabetic activities against cancer via the modulation of PI3K/Akt/mTOR cascade were identified. Taken together, the available data give an insight of the potential of repurposing medicinal plants and/or the individual secondary metabolites with antidiabetic activities for cancer therapy.

Lupeol induces autophagy and apoptosis with reduced cancer stem-like properties in retinoblastoma via phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin inhibition

OBJECTIVES

To evaluate the anticancer effects of lupeol in retinoblastoma cells.

METHODS

WERI-Rb-1 and Y-79 cell lines were used to evaluate the anticancer effect of lupeol. After lupeol treatment, the viability, proliferation, apoptosis, cancer stem-like properties, autophagy and in vivo tumour xenograft formation were detected.

KEY FINDINGS

In this study, lupeol decreased cell viability in both WERI-Rb-1 and Y-79 cell lines. Lupeol could also inhibit proliferation and induce apoptosis of RB cells, with increased Bax level and decreased Ki67, survivin and Bcl-2 levels. Furthermore, lupeol could suppress the spheroid formation and stem-like properties of RB cells. Moreover, LC3 II/LC3 I ratio and the levels of Beclin1 and ATG7 were increased after lupeol treatment, indicating that lupeol could induce autophagy in RB cells. Next, the inhibitory effect of lupeol on the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathway was observed. In tumour-bearing mice, lupeol suppressed tumour growth, and this might relate to its role in cell apoptosis, autophagy and stem-like properties.

CONCLUSIONS

Lupeol suppressed proliferation and cancer stem-like properties, and promoted autophagy and apoptosis of RB cells by restraining the PI3K/AKT/mTOR pathway.

Human Mesenchymal Stem Cell-Derived Exosomal microRNA-143 Promotes Apoptosis and Suppresses Cell Growth in Pancreatic Cancer via Target Gene Regulation

Background

This study aimed to explore the regulatory mechanism of hsa-miR-143-3p and lncRNA RP11-363N22.3-functioning upstream of KRAS-in exosomes derived from human mesenchymal stem cells (hMSCs) in pancreatic cancer.

Methods

Western blotting and quantitative PCR were used to determine gene expression. In vitro, cell proliferation, apoptosis, and cell cycle and invasion were evaluated using CCK-8 assay, flow cytometry, and transwell assays, respectively. In vivo, the effect of hsa-miR143-3p was investigated using a tumorigenesis test in nude mice. The association between hsa-miR-143-3p and lncRNA RP11-363N22.3 was investigated using the dual-luciferase assay.

Results

hsa-miR-143-3p expression significantly increased in hMSC exosomes than in those in human pancreatic cancer cell line (CFPAC-1) exosomes. In vitro, compared to the MOCK (CFPAC-1 only) group, cell proliferation and invasion were inhibited and apoptosis was induced in the inhibitor NC (CFPAC-1 + MSC-hsa-miR-3p inhibitor NC) group, while these changes were reversed in the inhibitor (CFPAC-1 + MSC-hsa-miR-3p inhibitor) group. The expression of lncRNA RP11-363N22.3 and genes related to miR-143 significantly decreased in the inhibitor NC group compared to the MOCK group, and increased in the inhibitor group compared to inhibitor NC group. A targeted combinatorial effect was observed between lncRNA RP11-363N22.3 and hsa-miR-143-3p. In vivo, the tumor volume of the mimics (CFPAC-1 + MSC-hsa-miR-143-3p mimics) group was smaller than that of the mimics NC (CFPAC-1 + MSC-hsa-miR-143-3p mimics NC) and MOCK groups. H&E staining showed that there were no obvious pathological changes in MOCK and mimic NC groups, while cell necrosis was seen in some regions in mimic groups.

Conclusion

hsa-miR-143-3p may promote apoptosis and suppress cell growth and invasion in pancreatic cancer.

Lupeol and its derivatives as anticancer and anti-inflammatory agents: Molecular mechanisms and therapeutic efficacy

Lupeol is a natural triterpenoid that widely exists in edible fruits and vegetables, and medicinal plants. In the last decade, a plethora of studies on the pharmacological activities of lupeol have been conducted and have demonstrated that lupeol possesses an extensive range of pharmacological activities such as anticancer, antioxidant, anti-inflammatory, and antimicrobial activities. Pharmacokinetic studies have indicated that absorption of lupeol by animals was rapid despite its nonpolar characteristics, and lupeol belongs to class II BCS (biopharmaceutics classification system) compounds. Moreover, the bioactivities of some isolated or synthesized lupeol derivatives have been investigated, and these results showed that, with modification to C-3 or C-19, some derivatives exhibit stronger activities, e.g., antiprotozoal or anticancer activity. This review aims to summarize the advances in pharmacological and pharmacokinetic studies of lupeol in the last decade with an emphasis on its anticancer and anti-inflammatory activities, as well as the research progress of lupeol derivatives thus far, to provide researchers with the latest information, point out the limitations of relevant research at the current stage and the aspects that should be strengthened in future research.

S-adenosylmethionine induces apoptosis and cycle arrest of gallbladder carcinoma cells by suppression of JAK2/STAT3 pathways

S-adenosylmethionine (SAM) is a naturally occurring physiologic molecule found ubiquitously in all mammalian cells and an essential compound in many metabolic pathways. It has been reported to possess many pharmacological properties including cancer-preventive and anticancer effects. However, the precise molecular mechanism involved in its anticancer effect is not yet clear. The present study is conducted to investigate the anticancer activity and the underlying mechanisms of SAM on human gallbladder cancer cells (GBC-SD and SGC-996) in vitro and in vivo. Cells were dealt with SAM and subjected to cell viability, colony formation, Hoechst staining, apoptosis, cycle arrest, western blot, and xenograft tumorigenicity assay. Experimental results showed that SAM could significantly inhibit the growth and proliferation and induce the apoptosis as well as cell cycle arrest in G0/G1 phase of GBC-SD and SGC-996 cells in a dose-dependent manner in vitro. The expression levels of p-JAK2, p-STAT3, Mcl-1, and Bcl-XL were significantly downregulated. In addition, inhibition of the JAK2/STAT3 pathway significantly enhanced the anti-apoptotic effect of SAM, suggesting the key roles of JAK2/STAT3 in the process. More importantly, our in vivo studies demonstrated that administration of SAM could significantly decrease the tumor weight and volume and immunohistochemistry analysis proved the downregulation of p-JAK2 and p-STAT3 in tumor tissues following SAM treatment, consistent with our in vitro results. In summary, our findings indicated that SAM can inhibit cell proliferation and induce apoptosis as well as cycle arrest of GBC cells by suppression of JAK2/STAT3 pathways and the dramatic effects of SAM hinting that SAM might be a useful therapeutic option for patients suffering from gallbladder cancer.

Arg-Gly-Asp-modified elastin-like polypeptide regulates cell proliferation and cell cycle proteins via the phosphorylation of Erk and Akt in pancreatic β-cell

Objective

Enhancement of β-cell proliferation plays an important role in maintaining β-cell mass and function, and in improving pancreatic β-cell survival before transplantation. Extracellular matrix (ECM) components increase the adhesion and proliferation of β-cells, and the RGD-modified elastin-like polypeptide (RGD-ELP, REP) has been described as a bioactive matrix. In this study, we investigated whether REP could enhance β-cell adhesion and proliferation and elucidated the signaling pathways involved.

Methods

We investigated the effect of REP on cell adhesion, proliferation and insulin secretion via assays using Rin-m and rat islets. Crystal violet, CCK-8, and BrdU assay, FACS, western blot, real time q-PCR analyses and insulin ELISA were examined. To explain the associated mechanisms, phosphorylation of Akt and extracellular signal-regulated kinase (Erk) were measured.

Results

REP more increased the adhesion, proliferation and survival of Rin-m cells compared to elastin-like poly peptide (ELP) without RGD-motif. The enhancement of β-cell proliferation by REP was associated with increased cyclin D1, cyclin D2 and cdk6, and decreased p27 levels. When β-cells were cultured on REP, Erk and the phosphatidylinositol 3-kinase (PI3-kinase) downstream effector, Akt was stimulated. Treatment with the Erk pathway inhibitor and PI3-kinase inhibitor decreased REP-induced β-cell adhesion and proliferation, and regulated REP-induced cell cycle proteins. Additionally, REP increased the mRNA and protein levels of insulin and its transcription factor, PDX-1, and insulin secretion.

Conclusions

Our results demonstrate that the up-regulation of the PI3K/Akt and Erk signaling pathways and the regulation of cell cycle proteins by REP could serve as effective strategies for improving pancreatic β-cell adhesion and proliferation.

Phytochemical profile and antiproliferative effect of Ficus crocata extracts on triple-negative breast cancer cells

Background

Some species of the Ficus genus show pharmacological activity, including antiproliferative activity, in cell lines of several cancer Types. ficus crocata is distributed in Mexico and used in traditional medicine, as it is believed to possess anti-inflammatory, analgesic, and antioxidant properties. However, as of yet, there are no scientific reports on its biological activity. This study aims to evaluate the phytochemical profile of F. crocata leaf extracts and their effects on breast cancer MDA-MB-231 cells proliferation. Moreover, the study aims to unearth possible mechanisms involved in the decrease of cell proliferation.

Methods

The extracts were obtained by the maceration of leaves with the solvents hexane, dichloromethane, and acetone. The phytochemical profile of the extracts was determined using gas chromatography coupled with mass analysis. Cell proliferation, apoptosis, and cell cycle analysis in MDA-MB-231 cells were determined using a Crystal violet assay, MTT assay, and Annexin-V/PI assay using flow cytometry. The data were analyzed using ANOVA and Dunnett’s test.

Results

The hexane (Hex-EFc), dichloromethane (Dic-EFc), and acetone (Ace-EFc) extracts of F. crocata decreased the proliferation of MDA-MB-231 cells, with Dic-EFc having the strongest effect. Dic-EFc was fractioned and its antiproliferative activity was potentiated, which enhanced its ability to induce apoptosis in MDA-MB-231 cells, as well as increased p53, procaspase-8, and procaspase-3 expression.

Conclusions

This study provides information on the biological activity of F. crocata extracts and suggests their potential use against triple-negative breast cancer.

Mapping Pharmacological Network of Multi-Targeting Litchi Ingredients in Cancer Therapeutics

Considerable pharmacological studies have demonstrated that the extracts and ingredients from different parts (seeds, peels, pulps, and flowers) of Litchi exhibited anticancer effects by affecting the proliferation, apoptosis, autophagy, metastasis, chemotherapy and radiotherapy sensitivity, stemness, metabolism, angiogenesis, and immunity via multiple targeting. However, there is no systematical analysis on the interaction network of “multiple ingredients-multiple targets-multiple pathways” anticancer effects of Litchi. In this study, we summarized the confirmed anticancer ingredients and molecular targets of Litchi based on published articles and applied network pharmacology approach to explore the complex mechanisms underlying these effects from a perspective of system biology. The top ingredients, top targets, and top pathways of each anticancer function were identified using network pharmacology approach. Further intersecting analyses showed that Epigallocatechin gallate (EGCG), Gallic acid, Kaempferol, Luteolin, and Betulinic acid were the top ingredients which might be the key ingredients exerting anticancer function of Litchi, while BAX, BCL2, CASP3, and AKT1 were the top targets which might be the main targets underling the anticancer mechanisms of these top ingredients. These results provided references for further understanding and exploration of Litchi as therapeutics in cancer as well as the application of “Component Formula” based on Litchi’s effective ingredients.

Chemosensitization of Therapy Resistant Tumors: Targeting Multiple Cell Signaling Pathways by Lupeol, A Pentacyclic Triterpene

Background:

The resistance of cancer cells to different therapies is one of the major stumbling blocks for successful cancer treatment. Various natural and pharmaceuticals drugs are unable to control drug-resistance cancer cell's growth. Also, chemotherapy and radiotherapy have several side effects and cannot apply to the patient in excess. In this context, chemosensitization to the therapy-resistant cells by non-toxic phytochemicals could be an excellent alternative to combat therapy-resistant cancers.

Objective:

To review the currently available literature on chemosensitization of therapy resistance cancers by Lupeol for clinically approved drugs through targeting different cell signaling pathways.

Methods:

We reviewed relevant published articles in PubMed and other search engines from 1999 to 2019 to write this manuscript. The key words used for the search were “Lupeol and Cancer”, “Lupeol and Chemosensitization”, “Lupeol and Cell Signaling Pathways”, “Cancer Stem Cells and Lupeol” etc. The published results on the chemosensitization of Lupeol were compared and discussed.

Results:

Lupeol chemosensitizes drug-resistant cancer cells for clinically approved drugs. Lupeol alone or in combination with approved drugs inhibits inflammation in different cancer cells through modulation of expression of IL-6, TNF-α, and IFN-γ. Lupeol, through altering the expression levels of BCL-2, BAX, Survivin, FAS, Caspases, and PI3K-AKT-mTOR signaling pathway, significantly induce cell deaths among therapy-resistant cells. Lupeol also modulates the molecules involved in cell cycle regulation such as Cyclins, CDKs, P53, P21, and PCNA in different cancer types.

Conclusion:

Lupeol chemosensitizes the therapy-resistant cancer cells for the treatment of various clinically approved drugs via modulating different signaling pathways responsible for chemoresistance cancer. Thus, Lupeol might be used as an adjuvant molecule along with clinically approved drugs to reduce the toxicity and increase the effectiveness.

Homeobox B5 suppression attenuates proliferation and elevates apoptosis in hepatoma cell lines through ERK/MDM2 signalling

Homeobox B5 (HOXB5), a member of the HOX gene family, is an important gene in tumourigenesis. However, its role in hepatocellular carcinoma (HCC) cell proliferation and apoptosis remains unclear. In this study, we investigated the role and regulation mechanism of HOXB5 in HCC cell lines Hep3B and LM6. The data indicated high expression of HOXB5 in HCC tissues and cell lines. In HCC cells, inhibition of HOXB5 by transfection with HOXB5 siRNA significantly constrained cell viability, and Bcl-2 levels, and it increased cell apoptosis, cytochrome c levels, BAX levels, and caspase-3 activity. On the contrary, HOXB5 overexpression increased proliferation and Bcl-2 levels but inhibited BAX levels and caspase-3 activity in these cells. HOXB5 downregulation attenuated activation of extracellular signal-regulated kinase (ERK) and expression of the murine double minute 2 (MDM2) oncogene. Incubation with the ERK activator, phorbol 12-myristate 13-acetate (40 μmol/L), for 12 hours reversed the effects of HOXB5 inhibition on MDM2 expression, cell proliferation, and apoptosis in HCC cells. Overall, this study demonstrated that HOXB5 inhibition regulated MDM2 expression by controlling ERK activation and that it modulated proliferation and apoptosis in HCC cells.

Secondary metabolites in plants: main classes, phytochemical analysis and pharmacological activities

Plants are an essential source of chemical compounds with different biological properties that man can use to his advantage. These substances are mainly produced as a result of chemical conversions of secondary metabolism. This article reviews the main classes of secondary metabolites that synthesize plants as well as their characteristics and their biological functions. Examples are provided for each of the classes. Emphasis is placed on the methods of extracting secondary metabolites and phytochemical screening, as well as on the main pharmacological activities described for the MS.

Plant triterpenoid saponins: biosynthesis, in vitro production, and pharmacological relevance

The saponins are a diverse class of natural products, with a broad scale distribution across different plant species. Chemically characterized as triterpenoid glycosides, they posses a 30C oxidosqualene precursor-based aglycone moiety (sapogenin), to which glycosyl residues are subsequently attached to yield the corresponding saponin. Based on the chemically distinct aglycone moieties, broadly, they are divided into triterpenoid saponins (dammaranes, ursanes, oleananes, lupanes, hopanes, etc.) and the sterol glycosides. This review aims to present in detail the biosynthesis patterns of the different aglycones from a common precursor and their glycosylation patterns to yield the functionally active glycoside. The review also presents recent advances in the pharmacological activities of these saponins, particularly as potent anti-neoplastic pharmacophores, antioxidants, or anti-viral/antibacterial agents. Since alternate production pedestals for these pharmacologically important triterpenes via cell and tissue cultures are an attractive option for their sustainable production, recent trends in the variety and scale of in vitro production of plant triterpenoids have also been discussed.

The Anti-proliferative Activity of GnRH Through Downregulation of the Akt/ERK Pathways in Pancreatic Cancer

Gonadotropin-releasing hormone (GnRH) has been demonstrated to exert anti-proliferative functions on various tumor cells in endometrial, ovarian, bladder, or prostate cancer as a part of the autocrine system. In addition, the expression levels of GnRH and its receptor had been identified in breast cancer or non-reproductive cancers, such as glioblastoma and pancreatic cancer. Previous studies have reported abnormal GnRH expression in several malignant tumors, suggesting that GnRH and its receptor might be essential for tumourigenesis. In the present study, we attempted to clarify the mechanisms underlying GnRH function in cell proliferation in pancreatic cancer. Our results indicated that GnRH expression might be essential for the malignancy of pancreatic cancer. We then found that GnRH overexpression can induce cell apoptosis through activating the Bcl-2/Bax pathway and autophagy might be involved in the GnRH-mediated apoptosis in Panc1 cells. Further investigation showed that the inhibition of GnRH may promote tumor invasion and migration through upregulation of MMP2 expression in pancreatic cancer cells. Moreover, our results indicated that GnRH can regulate the Akt/ERK1/2 pathways to promote cell proliferation by inhibiting cell apoptosis in Panc1 cells. Therefore, our finding exhibited that the regulation of GnRH expression may be essential for tumourigenesis in pancreatic cancer, and might be a potential target for the treatment of the patients with pancreatic cancer.

Oxymatrine Synergistically Potentiates the Antitumor Effects of Cisplatin in Human Gastric Cancer Cells

Cisplatin (CDDP) has been extensively used for gastric cancer (GC) treatment but limited by drug resistance and severe toxicity. The chemo-sensitizers that enhance its efficiency and overcome its limitation are urgently needed. Oxymatrine (OMT), a primary active ingredient from the dry roots of Sophora favescens, has shown powerful anti-cancer property with little side-effect. In this study, we explored the chemo-sensitization of OMT to potentiate the anti-tumor effect of CDDP. GC cell lines were dealt with OMT and/or CDDP and then subjected to different experimental methods. We found that OMT could significantly potentiate the CDDP-caused BGC-823 and SGC7901 cells viability loss, and OMT acts synergistically with CDDP. The combinative treatment could arrest cell cycle in G0/G1 phase by increasing p21, p27 and decreasing cyclin D1, and induced apoptosis by ROS generation and AKT/ERK inactivation. Inhibition of ROS respectively reversed the cell death induced by OMT and/or CDDP, suggesting the pivotal roles of ROS in the process. Moreover, OMT enhanced the antitumor effects of CDDP in nude mice bearing BGC823 tumor xenografts in vivo. Taken together, this study highlights that the co-treatment with OMT and CDDP exerted synergistic antitumor effects in GC cells, and that these effects may be mediated by ROS generation and inactivation of the AKT/ERK pathways.

Knockdown of AGR2 induces cell apoptosis and reduces chemotherapy resistance of pancreatic cancer cells with the involvement of ERK/AKT axis

BACKGROUND

Pancreatic cancer (PC), an aggressive human malignancy, presents with a striking resistance to chemotherapy. Interesting, AGR2 has been found to be upregulated in various cancers and has been found to promote the dissemination of PC cells. Thereby, a series of in-vitro experiments were performed to investigate the relationship between AGR2 and the ERK/AKT axis, and to explore whether it affects PC cells.

METHODS

Positive expression of AGR2 protein in the PC and paracancerous tissues collected from 138 patients with PC was detected using immunohistochemistry. After treatment with FGF2 (an ERK/AKT axis agonist), siRNA against AGR2 or their combination respectively, cell viability, chemotherapy resistance, radiotherapy resistance, migration, invasion and apoptosis in PC cells were detected using CCK8 assay, MTT assay, clone formation assay, wound healing assay, Transwell assay and flow cytometry, respectively. The expressions of AGR2 and ERK/AKT axis-related genes and proteins in tissues and cells were detected using reverse transcription quantitative polymerase chain reaction and Western blot assay.

RESULTS

PC tissues exhibited highly-expressed AGR2 and abnormally activated ERK/AKT axis. FGF2 promoted the expression of AGR2, ERK/AKT axis activation, cell viability, chemotherapy resistance, migration and invasion, but decreased cell apoptosis in PC cells. However, knockdown of AGR2 resulted in inhibition of the ERK/AKT axis, reduced PC cell viability, chemotherapy resistance, migration and invasion but increased cell apoptosis in PC cells.

CONCLUSION

The findings reveal that AGR2 silencing could promote cell apoptosis and inhibit cell migration, invasion and chemotherapy resistance of PC cell with the involvement of the ERK/AKT axis.

Lenalidomide improvement of cisplatin antitumor efficacy on triple-negative breast cancer cells in vitro

Lenalidomide is an immunomodulatory drug and possesses anti-angiogenic and immunomodulatory activities against multiple myeloma. The present study assessed the in vitro effect of lenalidomide combined with cisplatin on MDA-MB-231, a triple-negative breast cancer (TNBC) cell line and explored the underlying molecular mechanism of this combination. Cell viability, apoptosis and the protein expression of phosphorylated (p) and total extracellular signal-regulated kinase (ERK), B-cell lymphoma-2 (Bcl-2), caspase-3, cleaved poly-adenosine diphosphate-ribose polymerase (cPARP), vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) were measured in MDA-MB-231 cells treated with different concentrations of lenalidomide, cisplatin and their combination using different biochemical assays. Lenalidomide demonstrated no significant effect on the cell viability of MDA-MB-231 cells, even at high concentrations, whereas lenalidomide in combination with cisplatin, significantly reduced cisplatin IC₅₀ from 7.8 to 3.0 µM in MDA-MB-231 cells. In addition, lenalidomide and cisplatin in combination significantly induced cell apoptosis by 1.6- and 1.38-fold, respectively compared with lenalidomide and cisplatin alone (P<0.05). The expression levels of VEGF, bFGF and Bcl-2 proteins were significantly reduced (P<0.01), whereas caspase-3 and cleaved PARP expression were significantly increased in MDA-MB-231 cells treated with the combination compared to those treated with single agents (P<0.01). Lenalidomide treatment alone significantly reduced the p-ERK level compared with the control (P<0.05) and cisplatin treatment alone significantly increased it (P<0.01), however treatment with them in combination significantly reduced the p-ERK level in MDA-MB-231 cells compared with cisplatin treatment alone (P<0.05). In conclusion, the present study provides the basis for using lenalidomide in combination with cisplatin in TNBC therapy.

Oxymatrine synergistically enhances antitumor activity of oxaliplatin in colon carcinoma through PI3K/AKT/mTOR pathway

Oxymatrine (OMT), one of the main active components of extracts from the dry roots of Sophora flavescens, has been reported to possess many pharmacological properties including cancer-preventive and anti-cancer effects. The aim of the present study is to explore the efficiency of combination therapy with OMT and oxaliplatin (OXA) and identify the in vitro and in vivo cytotoxicity on colon cancer lines (HT29 and SW480) and mice model. Cells were treated with OMT and/or OXA and subjected to cell viability, colony formation, apoptosis, cell cycle, western blotting, xenograft tumorigenicity assay and immunohistochemistry. The results demonstrated that OMT and OXA inhibited the proliferation of colon cancer cells, and combination therapy of OMT and OXA resulted in a combination index < 1, indicating a synergistic effect. Co-treatment with OMT and OXA caused G0/G1 phase arrest by upregulating P21, P27 and downregulating cyclin D, and induced apoptosis through decreasing the expression of p-PI3K, p-AKT, p-mTOR, p-p70S6K. In addition, pretreatment with a specific PI3K/AKT activator (IGF-1) significantly neutralized the pro-apoptotic activity of OXA + OMT, demonstrating the important role of PI3K/AKT in this process. Moreover, in nude mice model, co-treatment displayed more efficient inhibition of tumor weight and volume on SW480 xenograft mouse model than single-agent treatment with OXA or OMT. Immunohistochemistry analysis suggests the combinations greatly suppressed tumor proliferation, which consistent with our in vitro results. In conclusion, our findings highlight that the combination therapy with OMT and OXA exerted synergistic antitumor effects in colon cancer cells through PI3K/AKT/mTOR pathway and combination treatment with OMT and OXA would be a promising therapeutic strategy for colon carcinoma treatment.

Metformin synergistically enhances antitumor activity of cisplatin in gallbladder cancer via the PI3K/AKT/ERK pathway

Metformin (Met) is a widely used antidiabetic drug and has demonstrated interesting anticancer effects in various cancer models, alone or in combination with chemotherapeutic drugs. The aim of the present study is to investigate the synergistic effect of Met with cisplatin (Cis) on the tumor growth inhibition of gallbladder cancer cells (GBC-SD and SGC-996) and explore the underlying mechanism. Cells were treated with Met and/or Cis and subjected to cell viability, colony formation, apoptosis, cell cycle, western blotting, xenograft tumorigenicity assay and immunohistochemistry. The results demonstrated that Met and Cis inhibited the proliferation of gallbladder cancer cells, and combination treatment with Met and Cis resulted in a combination index < 1, indicating a synergistic effect. Co-treatment with Met and Cis caused G0/G1 phase arrest by upregulating P21, P27 and downregulating CyclinD1, and induced apoptosis through decreasing the expression of p-PI3K, p-AKT, and p-ERK. In addition, pretreatment with a specific AKT activator (IGF-1) significantly neutralized the pro-apoptotic activity of Met + Cis, suggesting the key role of AKT in this process. More importantly, in nude mice model, Met and Cis in combination displayed more efficient inhibition of tumor weight and volume in the SGC-996 xenograft mouse model than Met or Cis alone. Immunohistochemistry analysis suggests the combinations greatly suppressed tumor proliferation, which is consistent with our in vitro results. In conclusion, our findings indicate that the combination therapy with Met and Cis exerted synergistic antitumor effects in gallbladder cancer cells through PI3K/AKT/ERK pathway, and combination treatment with Met and Cis would be a promising therapeutic strategy for gallbladder cancer patients.

Lupeol and Its Role in Chronic Diseases

Lupeol belongs to pentacyclic lupane-type triterpenes and exhibits in edible vegetables, fruits and many plants. Many researches indicated that lupeol possesses many beneficial pharmacological activities including antioxidant, anti-inflammatory, anti-hyperglycemic, anti-dyslipidemic and anti-mutagenic effects. From various disease-targeted animal models, these reports indicated that lupeol has anti-diabetic, anti-asthma, anti-arthritic, cardioprotective, hepatoprotective, nephroprotective, neuroprotective and anticancer efficiency under various routes of administration such as topical, oral, subcutaneous, intraperitoneal and intravenous. It is worth mentioning that clinical trials of lupeol were performed to treat canine oral malignant melanoma and human moderate skin acne in Japan and Korea. The detailed mechanism of anti-inflammatory, anti-diabetic, hepatoprotective and anticancer activities was further reviewed from published papers. These evidence indicate that lupeol is a multi-target agent to exert diverse pharmacological potency with many potential targeting proteins such as α-glucosidase, α-amylase, protein tyrosine phosphatase 1B (PTP 1B) and TCA cycle enzymes and targeting pathway such as IL-1 receptor-associated kinase-mediated toll-like receptor 4 (IRAK-TLR4), Bcl-2 family, nuclear factor kappa B (NF-kB), phosphatidylinositol-3-kinase (PI3-K)/Akt and Wnt/β-catenin signaling pathways. This review also provides suggestion that lupeol might be a valuable and potential lead compound to develop as anti-inflammatory, anti-diabetic, hepatoprotective and anticancer drugs.

Melicope ptelefolia leaf extracts exhibit antioxidant activity and exert anti-proliferative effect with apoptosis induction on four different cancer cell lines

Background

Melicope ptelefolia is a well-known herb in a number of Asian countries. It is often used as vegetable salad and traditional medicine to address various ailments. However, not many studies have been currently done to evaluate the medicinal benefits of M. ptelefolia (MP). The present study reports antioxidant, anti-proliferative, and apoptosis induction activities of MP leaf extracts.

Method

Young MP leaves were dried, powdered and extracted sequentially using hexane (HX), ethyl acetate (EA), methanol (MeOH) and water (W). Antioxidant activity was evaluated using ferric reducing antioxidant power (FRAP), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radicals scavenging and cellular antioxidant activity (CAA) assays. Anti-proliferative activity was evaluated through cell viability assay, using the following four human cancer cell lines: breast (HCC1937, MDA-MB-231), colorectal (HCT116) and liver (HepG2). The anti-proliferative activity was further confirmed through cell cycle and apoptosis assays, including annexin-V/7-aminoactinomycin D staining and measurements of caspase enzymes activation and inhibition.

Result

Overall, MP-HX extract exhibited the highest antioxidant potential, with IC₅₀ values of 267.73 ± 5.58 and 327.40 ± 3.80 μg/mL for ABTS and DPPH radical-scavenging assays, respectively. MP-HX demonstrated the highest CAA activity in Hs27 cells, with EC₅₀ of 11.30 ± 0.68 μg/mL, while MP-EA showed EC₅₀ value of 37.32 ± 0.68 μg/mL. MP-HX and MP-EA showed promising anti-proliferative activity towards the four cancer cell lines, with IC₅₀ values that were mostly below 100 μg/mL. MP-HX showed the most notable anti-proliferative activity against MDA-MB-231 (IC₅₀ = 57.81 ± 3.49 μg/mL) and HCT116 (IC₅₀ = 58.04 ± 0.96 μg/mL) while MP-EA showed strongest anti-proliferative activity in HCT116 (IC₅₀ = 64.69 ± 0.72 μg/mL). The anticancer potential of MP-HX and MP-EA were also demonstrated by their ability to induce caspase-dependent apoptotic cell death in all of the cancer cell lines tested. Cell cycle analysis suggested that both the MP-HX and MP-EA extracts were able to disrupt the cell cycle in most of the cancer cell lines.

Conclusions

MP-HX and MP-EA extracts demonstrated notable antioxidant, anti-proliferative, apoptosis induction and cancer cell cycle inhibition activities. These findings reflect the promising potentials of MP to be a source of novel phytochemical(s) with health promoting benefits that are also valuable for nutraceutical industry and cancer therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-017-1761-9) contains supplementary material, which is available to authorized users.

Matrine reduces the proliferation of A549 cells via the p53/p21/PCNA/eIF4E signaling pathway

The aim of the present study was to investigate how matrine affects the proliferation of A549 human lung adenocarcinoma cells via the p53/p21/proliferating cell nuclear antigen (PCNA)/eukaryotic translation initiation factor 4E (eIF4E) signaling pathway. The effect of different concentrations of matrine on the proliferation of A549 cells was investigated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The migration of A549 cells following exposure to varied concentrations of matrine was detected using a Transwell cell migration assay. The effect of 240 mg/l matrine on the apoptotic rate of A549 cells was determined using flow cytometry. The change in the mRNA and protein expression levels of p53, p21, PCNA and eIF4E following exposure to matrine were detected using reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. The increase of matrine from 60–240 mg/l led to reduced cell migration and inhibition of A549 cell proliferation. The apoptotic rate of A549 cells when treated with 240 mg/l matrine was significantly different when compared with the untreated control. The mRNA expression levels of p53 and p21 in the group treated with 240 mg/l matrine were significantly higher compared with the control group. The mRNA expression levels of PCNA and eIF4E were significantly lower in the 240 mg/l matrine-treated group compared with the control. The protein expression levels of p53 and p21 were significantly higher in the 240 mg/l matrine group compared with the control group. Treatment with 240 mg/l matrine reduced the protein expression levels of PCNA and eIF4E. Matrine also reduced the migration ability of A549 cells and inhibited their proliferation, which may be associated with the overexpression of p53 and p21, and the reduction of PCNA and eIF4E expression levels.

Diindolylmethane and Lupeol Modulates Apoptosis and Cell Proliferation in N-Butyl-N-(4-Hydroxybutyl) Nitrosamine Initiated and Dimethylarsinic Acid Promoted rat Bladder Carcinogenesis

Bladder cancer has been shown to resist programmed cell death with altered expression of both pro-apoptotic and anti-apoptotic proteins. To study is to investigate the apoptotic properties of Diindolylmethane (DIM) and Lupeol on N-Butyl-N-(4-hydroxybutyl) Nitrosamine (BBN) initiated and Dimethylarsinic Acid (DMA) promoted urinary bladder cancer. Sixty male Wistar rats were divided into 6 groups. Group I: Control. Group II: Rats were experimentally developed bladder carcinogenesis with BBN and DMA. Group III and IV: DIM and lupeol were administered after BBN treatment for 28 weeks. Group V and VI: DIM and lupeol alone treatment for 36 weeks. All the experimental rats were maintained and euthanized after 36 weeks protocol. Urinary bladder tissues were collected and processed for further investigations. Apoptotis and cell proliferative marker such as Bax, Bcl-2, caspase-3, caspase-9 and PCNA were quantified using immunohistochemical analysis. The Immunohistochemical expression of Bax, Bcl-2, caspase-3, caspase-9 and PCNA were aberrant in BBN + DMA treated tumor group. Administration of DIM and lupeol inhibited the progression of bladder cancer, induced the expression of apoptotic Bax, caspase-3, caspase-9 and inhibited the expression of anti-apoptotic Bcl-2, PCNA in the urinary bladder of rats. Administration of diindolylmethane and lupeol treatment induces apoptosis and cellular proliferation by its anti-carcinogenic properties. From our results DIM and lupeol would be the agent or adjunct for the treatment of bladder carcinogenesis.

Down-regulation of tumor endothelial marker 8 suppresses cell proliferation mediated by ERK1/2 activity

Tumor endothelial marker 8 (TEM8) was recently suggested as a putative anti-tumor target in several types of human cancer based on its selective overexpression in tumor versus normal endothelial cells. The objective of this study was to detect the potential functions of TEM8 in osteosarcoma. Overall, TEM8 was mainly located in cytoplasm and was up-regulated in osteosarcoma compared to benign bone lesions and adjacent non tumor tissue (ANT). High TEM8 expression group had a significant lower overall survival rate than that in the low TEM8 expression group. TEM8 knock-down by siRNA or shRNA results in significant reduction of osteosarcoma cell growth and proliferation both in vitro and in vivo. Ablation of TEM8 led to increasing of p21 and p27 and suppression of cyclin D1 mediated by Erk1/2 activity. These findings suggest that down-regulation of TEM8 play an important role in the inhibition of tumorigenesis and development of osteosarcoma.

Lupeol enhances inhibitory effect of 5-fluorouracil on human gastric carcinoma cells

Lupeol, a dietary triterpene present in many fruits and medicinal plants, has been reported to possess many pharmacological properties including cancer-preventive and anti-cancer effects in vitro and in vivo. Here, we investigated the anti-cancer efficacy and adjuvant chemotherapy action of lupeol in gastric cancer (GC) cells (SGC7901 and BGC823) and explored the underlying mechanisms. Cells were treated with lupeol and/or 5-fluorouracil (5-Fu) and subjected to cell viability, colony formation, apoptosis, western blot, semiquantitative RT-PCR, and xenograft tumorigenicity assay. Our results showed that lupeol and 5-Fu inhibited the proliferation of SGC7901 and BGC823 cells, and combination treatment with lupeol and 5-Fu resulted in a combination index < 1, indicating a synergistic effect. Co-treatment with lupeol and 5-Fu induced apoptosis through up-regulating the expressions of Bax and p53 and down-regulating the expressions of survivin and Bcl-2. Furthermore, co-treatment displayed more efficient inhibition of tumor weight and volume on BGC823 xenograft mouse model than single-agent treatment with 5-Fu or lupeol. Taken together, our findings highlight that lupeol sensitizes GC to 5-Fu treatment, and combination treatment with lupeol and 5-Fu would be a promising therapeutic strategy for human GC treatment.

Oxymatrine synergistically enhances the inhibitory effect of 5-fluorouracil on hepatocellular carcinoma in vitro and in vivo

Oxymatrine (OMT), one of the main active components of extracts from the dry roots of Sophora flavescens, has long been employed clinically to treat cancers. Here, we investigated the synergistic effect of OMT with 5-fluorouracil (5-Fu) on the tumor growth inhibition of hepatocellular carcinoma cells (HCC; Hep-G2 and SMMC-7721) and explored the underlying mechanism. Cells were treated with OMT and/or 5-Fu and subjected to cell viability, colony formation, apoptosis, cell cycle, western blotting, xenograft tumorigenicity assay, and immunohistochemistry. OMT and 5-Fu inhibited the proliferation of Hep-G2 and SMMC-7721 cells, and combination treatment with OMT and 5-Fu resulted in a combination index <1, indicating a synergistic effect. Co-treatment with OMT and 5-Fu caused G0/G1 phase arrest by upregulating P21 and P27 and downregulating cyclin D, and induced apoptosis through increasing the production of reactive oxygen species (ROS) and decreasing the levels of p-ERK. In addition, the inhibition of ROS respectively reversed the cell death induced by 5-Fu + OMT, suggesting the key roles of ROS in the process. More importantly, 5-Fu and OMT in combination exhibit much superior tumor weight and volume inhibition on SMMC-7721 xenograft mouse model in comparison to 5-Fu or OMT alone. Immunohistochemistry analysis suggests the combinations greatly suppressed tumor proliferation, which was consistent with our in vitro results. Taken together, our findings indicated that OMT sensitizes HCC to 5-Fu treatment by the suppression of ERK activation through the overproduction of ROS, and combination treatment with OMT and 5-Fu would be a promising therapeutic strategy for HCC treatment.

Lupeol Induces Apoptosis and Cell Cycle Arrest of Human Osteosarcoma Cells Through PI3K/AKT/mTOR Pathway

Lupeol, a dietary triterpene present in many fruits and medicinal plants, has been reported to possess many pharmacological properties including anticancer effect in vitro and in vivo However, the activity of lupeol against osteosarcoma remains unclear. The present study is conducted to investigate the anticancer activity and the underlying mechanisms of lupeol on human osteosarcoma cells (MNNG/HOS and MG-63) in vitro and in vivo MNNG/HOS and MG-63 cells were treated by lupeol and subjected to methyl thiazolyl tetrazolium analysis, Hoechst staining, annexin V/propidium iodide double staining, cell cycle analysis, and Western blot analysis. In addition, MNNG/HOS xenograft tumors were established in female nude BALB/c mice, and lupeol was intravenously administered to evaluate the anticancer capacity in vivo Our results showed that lupeol induced apoptosis as well as cell cycle arrest in G0/G1 phase of MNNG/HOS and MG-63 cells in a dose-dependent manner in vitro Furthermore, the protein expression levels of phospho-phosphatidylinositol 3-kinase (p-PI3K), phospho-protein kinase B (p-AKT), p-p70S6K, and cyclin D1 were significantly downregulated, whereas the expression levels of p21 and p27 were upregulated. These protein interactions may play a pivotal role in the regulation of apoptosis and cell cycle arrest. More importantly, our in vivo studies showed that administration of lupeol decreased tumor growth in a dose-dependent manner and has no significant effect on the function of liver and kidney. Taken together, our findings indicated that lupeol can induce apoptosis as well as cell cycle arrest of human osteosarcoma cells through phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin pathway and might offer a promising new approach in the effective treatment of osteosarcoma.