Brassinin Combined with Capsaicin Enhances Apoptotic and Anti-metastatic Effects in PC-3 Human Prostate Cancer Cells

Brassinin alleviates cancer cachexia by suppressing diverse inflammatory mechanisms in mice

Cancer cachexia is a multifactorial condition that contributes to the death of about 20% of cancer patients. It has the potential to cause weight loss, reduction in muscle mass, and loss of fat tissue, significantly lowering the quality of life. Currently, there are no approved drugs for cancer cachexia. Here, we have explored the possible impact of brassinin (BSN) on cancer cachexia under in vitro and in vivo settings. After differentiation, C2C12 and 3T3-L1 cells were incubated with colorectal carcinoma cells conditioned media or BSN. For preclinical studies, mice were injected with HT-29 cells followed by intraperitoneal administration of BSN, and muscle and adipose tissues were evaluated by Western blotting and hematoxylin and eosin staining. BSN effectively suppressed muscle atrophy by down-regulating the levels of Muscle RING-finger protein-1 and Atrogin-1, while also increasing the expression of myosin heavy chain in cachexia-induced-C2C12 myotubes. The induction of adipogenesis by BSN prevented adipocyte atrophy in cachexia-induced 3T3-L1 adipocytes. We also noted that BSN disrupted the interaction between COX-2 and signaling transducer and activator of transcription 3 (STAT3) promoter, leading to down-regulation of STAT3 activation. Moreover, it was found that BSN inhibited weight loss in mice and demonstrated anti-cachexic effects. Overall, our observations indicate that BSN can attenuate cancer cachexia through diverse mechanisms.

Investigation on the mechanisms by which the herbal remedies induce anti-prostate cancer activity: uncovering the most practical natural compound

Prostate cancer (PCa) is one of the most reported cancers among men worldwide. Targeting the essential proteins associated with PCa could be a promising method for cancer treatment. Traditional and herbal remedies (HRs) are the most practical approaches for PCa treatment. Here, the proteins and enzymes associated with PCa were determined based on the information obtained from the DisGeNET database. The proteins with a gene-disease association (GDA) score greater than 0.7 and the genes that have a disease specificity index (DSI) = 1 were selected as the target proteins. 28 HRs with anti-PCa activity as a traditional treatment for PCa were chosen as potential bioactive compounds. More than 500 compound-protein complexes were screened to find the top-ranked bioactives. The results were further evaluated using the molecular dynamics (MD) simulation and binding free energy calculations. The outcomes revealed that procyanidin B2 3,3'-di-O-gallate (B2G2), the most active ingredient of grape seed extract (GSE), can act as an agonist for PTEN. PTEN has a key role in suppressing PCa cells by applying phosphatase activity and inhibiting cell proliferation. B2G2 exhibited a considerable binding affinity to PTEN (11.643 kcal/mol). The MD results indicated that B2G2 could stabilize the key residues of the phosphatase domain of PTEN and increase its activity. Based on the obtained results, the active ingredient of GSE, B2G2, could play an agonist role and effectively increase the phosphatase activity of PTEN. The grape seed extract is a useful nutrition that can be used in men's diets to inhibit PCa in their bodies.Communicated by Ramaswamy H. Sarma.

Capsaicin: A chili pepper bioactive phytocompound with a potential role in suppressing cancer development and progression

Cancer profoundly influences morbidity and fatality rates worldwide. Patients often have dismal prognoses despite recent improvements in cancer therapy regimens. However, potent biomolecules derived from natural sources, including medicinal and dietary plants, contain biological and pharmacological properties to prevent and treat various human malignancies. Capsaicin is a bioactive phytocompound present in red hot chili peppers. Capsaicin has demonstrated many biological effects, including antioxidant, anti-inflammatory, antimicrobial, and anticarcinogenic capabilities. This review highlights the cellular and molecular pathways through which capsaicin exhibits antineoplastic activities. Our work also depicts the synergistic anticancer properties of capsaicin in conjunction with other natural bioactive components and approved anticancer drugs. Capsaicin inhibits proliferation in various cancerous cells, and its antineoplastic actions in numerous in vitro and in vivo carcinoma models impact oncogenesis, tumor-promoting and suppressor genes, and associated signaling pathways. Capsaicin alone or combined with other phytocompounds or approved antineoplastic drugs triggers cell cycle progression arrest, generating reactive oxygen species and disrupting mitochondrial membrane integrity, ultimately stimulating caspases and promoting death. Furthermore, capsaicin alone or in combination can promote apoptosis in carcinoma cells by enhancing the p53 and c-Myc gene expressions. In conclusion, capsaicin alone or in combination can have enormous potential for cancer prevention and intervention, but further high-quality studies are needed to firmly establish the clinical efficacy of this phytocompound.

Combined effects of two phytoalexins, brassinin and camalexin, on the cells of colorectal origin

Brassinin and camalexin belong to phytoalexins, plant compounds generated in the response to stress. Both compounds are known to be cytotoxic to several cancer cell lines, mainly by inducing oxidative stress and subsequent apoptosis. In the presented study, cytotoxic effects of brassinin and camalexin, individually and, for the first time, after combined exposure, on the cells of normal (CCD-Co18) and cancer (Caco-2) lines originated from colorectal tissues and their proapoptotic impact on Caco-2 cells were studied. The determined IC50 values indicate a clearly higher sensitivity of cancer cells to the tested substances, as well as a stronger cytotoxic effect of camalexin than brassinin. The synergistic effect of both phytoalexins was also demonstrated. Caspase-dependent and independent mechanisms were involved in the final effects. Both tested phytoalexins caused evident, concentration-dependent symptoms of oxidative stress in cancer cells, leading to apoptosis, but in the highest concentrations, also to necrosis. In case of camalexin, signs of pyroptosis were additionally detected.

The Apoptotic and Anti-Warburg Effects of Brassinin in PC-3 Cells via Reactive Oxygen Species Production and the Inhibition of the c-Myc, SIRT1, and β-Catenin Signaling Axis

Though Brassinin is known to have antiangiogenic, anti-inflammatory, and antitumor effects in colon, prostate, breast, lung, and liver cancers, the underlying antitumor mechanism of Brassinin is not fully understood so far. Hence, in the current study, the apoptotic mechanism of Brassinin was explored in prostate cancer. Herein, Brassinin significantly increased the cytotoxicity and reduced the expressions of pro-Poly ADP-ribose polymerase (PARP), pro-caspase 3, and B-cell lymphoma 2 (Bcl-2) in PC-3 cells compared to DU145 and LNCaP cells. Consistently, Brassinin reduced the number of colonies and increased the sub-G1 population and terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL)-positive cells in the PC-3 cells. Of note, Brassinin suppressed the expressions of pyruvate kinase-M2 (PKM2), glucose transporter 1 (GLUT1), hexokinase 2 (HK2), and lactate dehydrogenase (LDH) as glycolytic proteins in the PC-3 cells. Furthermore, Brassinin significantly reduced the expressions of SIRT1, c-Myc, and β-catenin in the PC-3 cells and also disrupted the binding of SIRT1 with β-catenin, along with a protein-protein interaction (PPI) score of 0.879 and spearman's correlation coefficient of 0.47 being observed between SIRT1 and β-catenin. Of note, Brassinin significantly increased the reactive oxygen species (ROS) generation in the PC-3 cells. Conversely, ROS scavenger NAC reversed the ability of Brassinin to attenuate pro-PARP, pro-Caspase3, SIRT1, and β-catenin in the PC-3 cells. Taken together, these findings support evidence that Brassinin induces apoptosis via the ROS-mediated inhibition of SIRT1, c-Myc, β-catenin, and glycolysis proteins as a potent anticancer candidate.

Naturally derived indole alkaloids targeting regulated cell death (RCD) for cancer therapy: from molecular mechanisms to potential therapeutic targets

Regulated cell death (RCD) is a critical and active process that is controlled by specific signal transduction pathways and can be regulated by genetic signals or drug interventions. Meanwhile, RCD is closely related to the occurrence and therapy of multiple human cancers. Generally, RCD subroutines are the key signals of tumorigenesis, which are contributed to our better understanding of cancer pathogenesis and therapeutics. Indole alkaloids derived from natural sources are well defined for their outstanding biological and pharmacological properties, like vincristine, vinblastine, staurosporine, indirubin, and 3,3′-diindolylmethane, which are currently used in the clinic or under clinical assessment. Moreover, such compounds play a significant role in discovering novel anticancer agents. Thus, here we systemically summarized recent advances in indole alkaloids as anticancer agents by targeting different RCD subroutines, including the classical apoptosis and autophagic cell death signaling pathways as well as the crucial signaling pathways of other RCD subroutines, such as ferroptosis, mitotic catastrophe, necroptosis, and anoikis, in cancer. Moreover, we further discussed the cross talk between different RCD subroutines mediated by indole alkaloids and the combined strategies of multiple agents (e.g., 3,10-dibromofascaplysin combined with olaparib) to exhibit therapeutic potential against various cancers by regulating RCD subroutines. In short, the information provided in this review on the regulation of cell death by indole alkaloids against different targets is expected to be beneficial for the design of novel molecules with greater targeting and biological properties, thereby facilitating the development of new strategies for cancer therapy.

Capsaicin: A Two-Decade Systematic Review of Global Research Output and Recent Advances Against Human Cancer

Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is one of the most important natural products in the genus Capsicum. Due to its numerous biological effects, there has been extensive and increasing research interest in capsaicin, resulting in increased scientific publications in recent years. Therefore, an in-depth bibliometric analysis of published literature on capsaicin from 2001 to 2021 was performed to assess the global research status, thematic and emerging areas, and potential insights into future research. Furthermore, recent research advances of capsaicin and its combination therapy on human cancer as well as their potential mechanisms of action were described. In the last two decades, research outputs on capsaicin have increased by an estimated 18% per year and were dominated by research articles at 93% of the 3753 assessed literature. In addition, anti-cancer/pharmacokinetics, cytotoxicity, in vivo neurological and pain research studies were the keyword clusters generated and designated as thematic domains for capsaicin research. It was evident that the United States, China, and Japan accounted for about 42% of 3753 publications that met the inclusion criteria. Also, visibly dominant collaboration nodes and networks with most of the other identified countries were established. Assessment of the eligible literature revealed that the potential of capsaicin for mitigating cancer mainly entailed its chemo-preventive effects, which were often linked to its ability to exert multi-biological effects such as anti-mutagenic, antioxidant and anti-inflammatory activities. However, clinical studies were limited, which may be related to some of the inherent challenges associated with capsaicin in the limited clinical trials. This review presents a novel approach to visualizing information about capsaicin research and a comprehensive perspective on the therapeutic significance and applications of capsaicin in the treatment of human cancer.

Daidzin targets epithelial-to-mesenchymal transition process by attenuating manganese superoxide dismutase expression and PI3K/Akt/mTOR activation in tumor cells

AIMS

Epithelial-mesenchymal transition (EMT) is a process during which epithelial cells lose their polarity and gain invasive properties to transform into mesenchymal cells. A few recent studies have reported that manganese superoxide dismutase (MnSOD) can effectively modulate EMT phenotype by influencing cellular redox environment via altering the intracellular ratio between O₂^- and H₂O₂. Daidzin (DDZ), a naturally occurring isoflavone isolated from Pueraria lobate (Fabaceae), has numerous pharmacologic effects including anti-cholesterol, anti-angiocardiopathy, anti-cancer. However, the potential inhibitory impact of DDZ on cancer metastasis and specifically on the EMT process has not been evaluated. We aimed to evaluate the possible relationship between MnSOD and EMT as well as influence of DDZ on these two processes in colon and prostate carcinoma cells.

MAIN METHODS

Cell viability was measured by MTT and real time cell analysis (RTCA) assay. Protein expression level of EMT markers and Akt/mTOR/PI3K signaling pathway were evaluated by Western blot analysis. Expression of EMT markers in cells was observed by immunocytochemistry. Cell invasion and migrations were evaluated by wound healing assay and Boyden chamber assay.

KEY FINDINGS

DDZ can block EMT accompanied with down-regulation of MnSOD, fibronectin, vimentin, MMP-9, MMP-2, N-cadherin, twist, and Snail, and up-regulation of occludin and E-cadherin in both unstimulated and TGFβ-induced cells. In addition, DDZ exposure also attenuated cell proliferation, invasion, and metastasis by reversing the EMT process in SNU-C2A, DU145, and PC-3 cells. DDZ treatment also modulated activation of PI3K/Akt/mTOR signaling cascades in DU145 cells. Moreover, an overexpression of MnSOD or silencing of MnSOD expression modulated EMT-related proteins, PI3K/Akt/mTOR activation and invasive activity.

SIGNIFICANCE

This is first finding on the DDZ in regulating MnSOD and EMT process by targeting PI3K/Akt/mTOR pathway in both colorectal and prostate cancer cell lines. Our data indicated that DDZ might act as a potent suppressor of EMT by affecting MnSOD expression in tumor cells.

Cancer Therapy Challenge: It Is Time to Look in the "St. Patrick's Well" of the Nature

Cancer still remains a leading cause of death despite improvements in diagnosis, drug discovery and therapy approach. Therefore, there is a strong need to improve methodologies as well as to increase the number of approaches available. Natural compounds of different origins (i.e., from fungi, plants, microbes, etc.) represent an interesting approach for fighting cancer. In particular, synergistic strategies may represent an intriguing approach, combining natural compounds with classic chemotherapeutic drugs to increase therapeutic efficacy and lower the required drug concentrations. In this review, we focus primarily on those natural compounds utilized in synergistic approached to treating cancer, with particular attention to those compounds that have gained the most research interest.

Ginkgolide C promotes apoptosis and abrogates metastasis of colorectal carcinoma cells by targeting Wnt/β-catenin signaling pathway

Ginkgolide C (GGC), isolated from Ginkbiloba, has been reported to display various pharmacological actions, although, anti-cancer effect of GGC has been poorly understood till now. This study aimed to investigate whether GGC can exhibit anti-neoplastic effects against colon cancer cells and explore underlying mechanism. The Wnt/β-catenin signaling can regulate cell proliferation, survival, metastasis, and migration. Wnt/β-catenin signaling pathway plays important role in colorectal cancer (CRC) and acts as a potential therapeutic target. Abnormal activation of this signaling cascades has been reported in colon CRC. We found that GGC down-regulated Wnt/β-catenin signaling cascade. GGC inhibited the expression of Wnt3a, β-catenin, and β-catenin down-stream signals (Axin-1, p-GSK3β, and β-TrCP). Also, GGC suppressed the expression of Wnt/β-catenin pathway target genes including c-myc, cyclin D1, and survivin. Additionally, GGC induced apoptosis and suppressed cell proliferation, invasion, and migration. GGC down-regulated the expressions of matrix metalloproteinase (MMP)-9 and MMP-2 proteins. Moreover, silencing of β-catenin by small interfering RNA (siRNA) enhanced the GGC-induced apoptosis and inhibitory action of GGC on invasion. Overall, our results indicate that GGC can reduce proliferation and promote apoptosis in colon cancer cells through inhibition of the Wnt/β-catenin signaling pathway. Thus, GGC can serve as a potent therapeutic agent for management of colon cancer as a novel wnt signaling inhibitor.

Brassinin Inhibits Proliferation in Human Liver Cancer Cells via Mitochondrial Dysfunction

Brassinin is a phytochemical derived from Chinese cabbage, a cruciferous vegetable. Brassinin has shown anticancer effects on prostate and colon cancer cells, among others. However, its mechanisms and effects on hepatocellular carcinoma (HCC) have not been elucidated yet. Our results confirmed that brassinin exerted antiproliferative effects by reducing proliferating cell nuclear antigen (PCNA) activity, a proliferation indicator and inducing cell cycle arrest in human HCC (Huh7 and Hep3B) cells. Brassinin also increased mitochondrial Ca²⁺ levels and depolarized the mitochondrial membrane in both Huh7 and Hep3B cells. Moreover, brassinin generated high amounts of reactive oxygen species (ROS) in both cell lines. The ROS scavenger N-acetyl-L-cysteine (NAC) inhibited this brassinin-induced ROS production. Brassinin also regulated the AKT and mitogen-activated protein kinases (MAPK) signaling pathways in Huh7 and Hep3B cells. Furthermore, co-administering brassinin and pharmacological inhibitors for JNK, ERK1/2 and P38 decreased cell proliferation in both HCC cell lines more than the pharmacological inhibitors alone. Collectively, our results demonstrated that brassinin exerts antiproliferative effects via mitochondrial dysfunction and MAPK pathway regulation on HCC cells.

LDL cholesterol promotes the proliferation of prostate and pancreatic cancer cells by activating the STAT3 pathway

Hypercholesterolemia has been found to be closely linked with a significant increase in both cancer incidence and mortality. However, the exact correlation between serum cholesterol levels and cancer has not been completely deciphered. Here we analyzed the effect of low-density lipoprotein (LDL) cholesterol on prostate and pancreatic cancer cells. We noted that LDL induced a substantial STAT3 activation and JAK1, JAK2, Src activation in diverse prostate and pancreatic tumor cells. Moreover, LDL promoted cancer cell proliferation, migration, and invasion as well as upregulated the expression of diverse oncogenic gene products. However, deletion of LDL-activated STAT3 in LNCaP and PANC-1 cells and reduced LDL-induced cell viability. Simvastatin (SV) treatment also alleviated LDL-induced cell viability and migration ability in both the prostate and pancreatic tumor cells. These results demonstrate that LDL-induced STAT3 activation may exert a profound effect on the proliferation and survival of tumor cells.

Corilagin Represses Epithelial to Mesenchymal Transition Process Through Modulating Wnt/β-Catenin Signaling Cascade

Corilagin (CLG), a major component of several medicinal plants, can exhibit diverse pharmacological properties including those of anti-cancer, anti-inflammatory, and hepatoprotective qualities. However, there are no prior studies on its potential impact on the epithelial-to-mesenchymal transition (EMT) process. EMT can lead to dissemination of tumor cells into other organs and promote cancer progression. Hence, we aimed to investigate the effect of CLG on EMT and its mechanism(s) of action in tumor cells. We noted that CLG reduced the expression of various epithelial markers and up-regulated the expression of Occludin and E-cadherin in both basal and TGFβ-stimulated tumor cells. CLG treatment also abrogated cellular invasion and migration in colon and prostate carcinoma cells. In addition, CLG effectively attenuated the Wnt/β-catenin signaling cascade in TGFβ-stimulated cells. Overall, our study suggests that CLG may function as and effective modulator of EMT and metastasis in neoplastic cells.

The Potential of Phytochemicals in Oral Cancer Prevention and Therapy: A Review of the Evidence

The etiological factors of oral cancer are complex including drinking alcohol, smoking tobacco, betel quid chewing, human papillomavirus infection, and nutritional deficiencies. Understanding the molecular mechanism of oral cancer is vital. The traditional treatment for patients with oral squamous cell carcinoma (e.g., surgery, radiotherapy, and chemotherapy) and targeted molecular therapy still have numerous shortcomings. In recent years, the use of phytochemical factors to prevent or treat cancer has received increasing attention. These phytochemicals have little or no toxicity against healthy tissues and are thus ideal chemopreventive agents. However, phytochemicals usually have low water solubility, low bioavailability, and insufficient targeting which limit therapeutic use. Numerous studies have investigated the development of phytochemical delivery systems to address these problems. The present article provides an overview of oral cancer including the etiological factors, diagnosis, and traditional therapy. Furthermore, the classification, dietary sources, anticancer bioactivity, delivery system improvements, and molecular mechanisms against oral cancer of phytochemicals are also discussed in this review.

A facile approach for fabricating CD44-targeted delivery of hyaluronic acid-functionalized PCL nanoparticles in urethane-induced lung cancer: Bcl-2, MMP-9, caspase-9, and BAX as potential markers

Lung carcinoma ranks highest in cancer-related death (about 20% of total cancer deaths) due to poor prognosis and lack of efficient management therapy. Owing to the lack of effective therapeutic approaches, survival rate of less than 5 years persists over the years among non-small cell lung cancer (NSCLC) patients. Capsaicin (CAP) is well reported for its antiproliferative and antioxidant properties in various literature but lacks an appropriate delivery carrier. The present study was aimed to develop CAP-loaded hyaluronic acid (HA) nanoparticles (NPs) utilizing layer by layer technique to achieve enhanced and precise delivery as well as target specificity. The NPs were evaluated for in vitro release, particle size, zeta potential, and cytotoxicity on A549 cells. The optimized NPs exhibited a particle size of 194 ± 2.90 nm, - 27.87 ± 3.21 mV zeta potential, and 80.70 ± 4.29% release, respectively, over a period of 48 h. Flow cytometric analysis revealed superior performance of HA-PCL-CAP in terms of suppressed cell viability in A549 cell lines when compared with CAP and PCL-CAP. Further, HA-anchored NPs were evaluated in vivo for their therapeutic efficacy in urethane-induced lung carcinoma in rat model. The superlative therapeutic potential of HA-PCL-CAP was advocated from the results of reactive oxygen species and mitochondrial membrane-mediated apoptosis. HA-PCL-CAP-administered groups presented greater therapeutic efficacy as revealed through reduced tumor volume and improved animal survival rate. A greater drug accumulation in tumor tissue as revealed from biodistribution studies evidences targeting potential of HA-PCL-CAP in urethane-induced lung carcinoma. Graphical abstract ᅟ.

Theacrine attenuates epithelial mesenchymal transition in human breast cancer MDA-MB-231 cells

Theacrine, a purine alkaloid structurally similar to caffeine, has recently become of interest as a potential therapeutic compound. Here, we investigated the antimetastatic potential of theacrine on human breast cancer MDA-MB-231 cells. We observed that theacrine can reverse epithelial-to-mesenchymal transition (EMT), which resulted in a decrease in the levels of mesenchymal markers (Fibronectin, Vimentin, N-cadherin, Twist, and Snail) and an increase in the levels of epithelial markers (Occludin and E-cadherin) in the cells. Additionally, theacrine attenuates TGF-β-induced EMT, cell adhesion, migration, and invasion in MDA-MB-231 cells. Overall, our results suggest that theacrine may inhibit the breast cancer cell metastasis by reversing the EMT process.

Liquid chromatographic chiral recognition of phytoalexins on immobilized polysaccharides chiral stationary phases. Unusual temperature behavior

Three immobilized polysaccharide chiral stationary phases, Chiralpak IA, Chiralpak IB and Chiralpak IC, were used for the study of enantioseparation of 36 derivatives of natural indole phytoalexins, in most cases bioactive, including racemic spirobrassinin, 1-methoxyspirobrassinin and 1-methoxyspirobrassinol methyl ether. Almost all analytes were baseline resolved at least on two different polysaccharide columns in normal phase mode. The effects of mobile phase composition, the analyte structure and the column temperature on the retention and enantioseparation were investigated. Evaluation of the corresponding thermodynamic parameters using van´t Hoff plots (ln k versus 1/T) in the temperature range -15 to 50 °C indicated that separations were enthalpy controlled in most cases, but some entropy controlled separations were also observed. Moreover, unusual phenomenon, an increase retention with increasing temperature accompanied with increased resolution was observed on the Chiralpak IC column. The elution order of enantiomers was determined in some cases and reversed elution order was also observed.

Brassinin Represses Invasive Potential of Lung Carcinoma Cells through Deactivation of PI3K/Akt/mTOR Signaling Cascade

The epithelial–mesenchymal transition (EMT) is a phenomenon that facilitates epithelial cells to acquire invasive potential to induce the initiation the metastatic spread of tumor cells. Here, we determined if brassinin (BSN) can affect the EMT process and deciphered its anti-cancer effects. BSN attenuated the levels of EMT linked genes and suppressed transforming growth factor beta (TGF-β)-mediated regulation of diverse mesenchymal markers. Additionally, BSN did increase the expression of various epithelial marker proteins in lung cancer cells. TGF-β-induced morphological changes and induction of invasive ability of tumor cells was also found to be abrogated by BSN treatment. Finally, BSN not only suppressed constitutive, but also inducible phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) phosphorylation in tumor cells.

Conditioned media from adipocytes promote proliferation, migration, and invasion in melanoma and colorectal cancer cells

Epidemiological evidence suggests that obesity can significantly increase the risk of various cancers, although the mechanisms underlying this link are completely unknown. Here, we analyzed the effect of adipocytes on melanoma and colon cancer cells proliferation, migration, and invasion. The potential effects of conditioned media (CM) obtained from differentiated mouse 3T3-L1 cells and human adipose tissue-derived mesenchymal stem cells (hAMSC) on the proliferation, migration, and invasion of B16BL6 melanoma and colon 26-L5 cancer cells were investigated. The 3T3-L1 and hAMSC CM increased cell proliferation, migration, and invasion in both the cell lines. In addition, adipocytes CM increased matrix metalloproteinase 9 (MMP-9) and MMP-2 activity in both B16BL6 and colon 26-L5 cells. These effects were found to be associated with an increased expression of various oncogenic proteins in B16BL6 and colon 26-L5 cells. Also, adipocyte CM induced Akt and mTOR activation in both tumor cell lines, and the pharmacological inhibition of Akt and mTOR blocked the CM induced Akt as well as mTOR activation and CM-stimulated melanoma and colon cancer cell proliferation, migration, and invasion. These data suggest that adipocyte promotes melanoma and colon cancer progression through modulating the expression of diverse proteins associated with cancer growth and metastasis as well as modulation of the Akt/mTOR signaling.

Combination of the natural product capsaicin and docetaxel synergistically kills human prostate cancer cells through the metabolic regulator AMP-activated kinase

Background

Current chemotherapy for castration-resistant prostate cancer is established on taxane-based compounds like docetaxel. However, eventually, the development of toxic side effects and resistance limits the therapeutic benefit being the major concern in the treatment of prostate cancer. Combination therapies in many cases, enhance drug efficacy and delay the appearance of undesired effects, representing an important option for the treatment of castration-resistant prostate cancer. In this study, we tested the efficacy of the combination of docetaxel and capsaicin, the pungent ingredient of hot chili peppers, on prostate cancer cells proliferation.

Methods

Prostate cancer LNCaP and PC3 cell lines were used in this study. Levels of total and phosphorylated forms of Akt, mTOR, S6, LKB1, AMPK and ACC were determined by Western blot. AMPK, LKB1 and Akt knock down was performed by siRNA. PTEN was overexpressed by transient transfection with plasmids. Xenograft prostate tumors were induced in nude mice and treatments (docetaxel and capsaicin) were administered intraperitoneally. Statistical analyses were performed with GraphPad software. Combination index was calculated with Compusyn software.

Results

Docetaxel and capsaicin synergistically inhibited the growth of LNCaP and PC3 cells, with a combination index lower than 1 for most of the combinations tested. Co-treatment with docetaxel and capsaicin notably decreased Akt and its downstream targets mTOR and S6 phosphorylation. Overexpression of PTEN phosphatase abrogated the synergistic antiproliferative effect of docetaxel and capsaicin. The combined treatment also increased the phosphorylation of AMP-activated kinase (AMPK) and the phosphorylation of its substrate ACC. In addition, pharmacological inhibition of AMPK with dorsomorphin (compound C) as well as knock down by siRNA of AMPK or its upstream kinase LKB1, abolished the synergy of docetaxel and capsaicin. Mechanistically, we showed that the synergistic anti-proliferative effect may be attributed to two independent effects: Inhibition of the PI3K/Akt/mTOR signaling pathway by one side, and AMPK activation by the other. In vivo experiments confirmed the synergistic effects of docetaxel and capsaicin in reducing the tumor growth of PC3 cells.

Conclusion

Combination of docetaxel and capsaicin represents a therapeutically relevant approach for the treatment of Prostate Cancer.

Arctiin is a pharmacological inhibitor of STAT3 phosphorylation at tyrosine 705 residue and potentiates bortezomib-induced apoptotic and anti-angiogenic effects in human multiple myeloma cells

BACKGROUND

Arctiin is a main component from the fruits of Arctium lappa L., that can be prescribed for cold or flu in East Asian countries; it has also been found to exert chemopreventive actions against various tumor cells.

HYPOTHESIS

In view of this evidence, we examined arctiin for its ability to trigger apoptosis and inhibit the activation of signal transducer and activator of transcription 3 (STAT3) in human multiple myeloma (MM) cells.

METHODS

We evaluated the effect of arctiin on STAT3 signaling cascades and its regulated functional responses in MM cells.

RESULTS

Arctiin effectively blocked the constitutive activation of STAT3 phosphorylation in the residue of tyrosine 705. Arctiin also abrogated the constitutive activation of Src phosphorylation and Janus-activated kinases (JAKs) 1/2. Furthermore, it was found that arctiin treatment clearly enhanced the mRNA and protein levels of protein tyrosine phosphatase ε (PTPε), and the silencing of PTPε caused a reversal of the arctiin-induced PTPε expression and the blockadge of STAT3 phosphorylation. Interestingly, arctiin could not repress IL-6-induced STAT3 activation in serum-starved U266 cells and when arctiin was incubated with a complete culture medium in RPMI 8226 and MM.1S cells. Arctiin suppressed cell proliferation, accumulated cells in the G2/M cell-cycle phase, and induced apoptosis within U266 cells, although the knockdown of PTPε prevented PARP cleavage and caspase-3 activation induced by the arctiin. In addition, arctiin exerted cytotoxicity in MM cells, but did not do so in peripheral blood mononuclear cells. Arctiin down-modulated diverse oncogenic gene products regulated by STAT3, although the induction of apoptosis by arctiin was abrogated upon transfection with pMXs-STAT3C in mouse embryonic fibroblast (MEF) cells. Arctiin also potentiated bortezomib-induced antitumor effects in U266 cells.

CONCLUSION

On the whole, our results indicate that arctiin is a potentially new inhibitor of constitutive STAT3 activation through the induction of PTPε in MM, cells and therefore has great value in treating various tumors sheltering constitutively activated STAT3.

A synergistic approach for management of lung carcinoma through folic acid functionalized co-therapy of capsaicin and gefitinib nanoparticles: Enhanced apoptosis and metalloproteinase-9 down-regulation

BACKGROUND

Lung cancer is one of the most lethal cancers and lacks effective treatment strategy. Therapeutic efficacy can be improved through active targeting approach utilizing surface engineered nanoparticles (NPs) for cancer therapy.

PURPOSE

The present study envisioned development of Folic acid (FA) functionalized NPs for co-administration of gefitinib (Gnb) and capsaicin (Cap) respectively to enhance the therapeutic outcome by disabling the barriers related to tumors extracellular matrix.

RESEARCH METHODS AND PROCEDURE

The FA conjugated Gnb/Cap polymeric (PLGA-PEG) NPs were prepared using oil in water emulsion technique and methodically developed using Quality by Design (QbD) concept employing central composite design. The developed formulations were subjected to various in vitro (A549 cell lines) and in vivo evaluations in urethane-induced lung cancer.

RESULTS

The modified NPs displayed particle sizes of 217.0 ± 3.2 nm and 213.0 ± 5.2 nm and drug release of 85.65 ± 3.21% and 81.43 ± 4.32% for Gnb and Cap respectively. Higher cellular uptake and lower cell viability in A549 cell line was displayed by functionalized NPs compared to free drug. Co administration of Gnb and Cap NPs displayed significant targeting potential, reduction in tumor volume while restoring the biochemical parameters viz., SOD, catalase, TBARS and protein carbonyl, towards normal levels when compared with toxic group. Significant down regulation was observed for anti-apoptotic proteins (MMP-9) and up regulation of pro-apoptotic proteins (caspase-3, caspase-9 and MMP-9) with co-therapy of Gnb and Cap NPs, when compared with individual therapy through Gnb/Cap.

CONCLUSION

Potentiation of the action of Gnb when co administered with Cap NPs can be a promising breakthrough for developing safe, effective and targeted delivery for lung carcinoma therapy.

The combined treatment of brassinin and imatinib synergistically downregulated the expression of MMP-9 in SW480 colon cancer cells

In cancer treatment, which is a major cause of mortality today, combination studies with clinically used chemotherapeutics are becoming increasingly important as much as investigating the effects of novel natural compounds. In this context, phytoalexins constitute an important group due to their unique structure. Brassinin is an essential indole phytoalexin and is a biosynthetic precursor for other phytoalexins. The purpose of this study was to evaluate the anticancer effects of brassinin in combination with imatinib in SW480 cells. In the study, it was observed that brassinin-imatinib combination significantly increased cytotoxicity compared with the single treatment of both compounds and inhibited cell cycle at G0/G1 phase. Annexin V binding and fluorescence imaging assays showed that the combination of brasinin-imatinib induces apoptosis in a dose-dependent manner. Furthermore, the effect of brassinin on the activity of MMP-9 in SW480 cells was evaluated for the first time, and it was detected that MMP-9 activity was significantly reduced. The combination of brassinin-imatinib was found to inhibit MMP-9 activity as well as relative MMP-9 gene expression on a higher level compared with control and compounds alone. Our findings have revealed that the combination of brassinin-imatinib synergistically induces cytotoxicity and apoptosis in SW480 cells. The findings on MMP-9 downregulation have also revealed the anti-metastatic potential of treatment.

Design, synthesis and biological evaluation of novel carbamodithioates as anti-proliferative agents against human cancer cells

A series of new carbamodithioates compounds has been successfully synthesized. All the carbamodithioate derivatives of SFE and SFA with benzenethiols (substituted or unsubstituted) exhibited, in general, higher percentages of inhibition than their parent compounds: SFE and SFA. A number of carbamodithioate derivatives with benzenethiols (substituted or unsubstituted) (1l, 1m, 1n, 1o, 1q, 1s, 2l, 2n, 2p, 2q, 2r and 2s) were investigated for in vitro anti-proliferative activities against five cancer cell lines: SMMC-7721, A549, A375, HCT 116 and Hela. The carbamodithioate compounds (1l, 1m, 1n, 1o, 1q and 1s) derived from SFE and the carbamodithioate compounds (2l, 2n, 2p, 2q, 2r and 2s) derived from SFA are more sensitive toward SMMC-7721and A549 cancer cells than toward other cancer cells in that their IC₅₀ values are appreciably lower. Moreover, they exhibited stronger inhibitory activities than their parent compound SFE and SFE. Further investigation indicated that these carbamodithioate derivatives inhibited colony formation of SMMC-7721 and remarkably induced the G2/M or G0/G1 phase cell cycle arrest and apoptosis in SMMC-7721 cancer cells. More important, these carbamodithioate derivatives are stable in protic solvent media than their parent compounds. By virtue of the simplicity of the preparation of these carbamodithioate derivatives and their stability, compounds 1m and 2s could be the promising candidates for replacement for their parent SFE and SFA for cancer prevention agents.

Bergamottin Suppresses Metastasis of Lung Cancer Cells through Abrogation of Diverse Oncogenic Signaling Cascades and Epithelial-to-Mesenchymal Transition

Bergamottin (BGM) is a naturally occurring furanocoumarin and is known to inhibit the growth of tumor cells. However, there is no available evidence that BGM has an inhibitory effect on cancer metastasis, specifically on the epithelial-to-mesenchymal transition (EMT) process in the malignant cells. Here we aimed to evaluate the antimetastatic potential of BGM in human lung adenocarcinoma cells. Our results demonstrate that BGM can block EMT, and observed inhibition was accompanied by downregulation of fibronectin, vimentin, N-cadherin, twist and snail expression, and upregulation of occludin and E-cadherin. Interestingly, transforming growth factor-β (TGF-β)-induced upregulation of fibronectin, vimentin, N-cadherin, twist and snail, and downregulation of occludin and E-cadherin, were abrogated by BGM treatment. Moreover, the treatment of BGM repressed TGF-β-induced cell invasive potential. BGM treatment also inhibited multiple oncogenic cascades such as PI3K/Akt/mTOR. Overall, the results demonstrate the potential antimetastatic activity of BGM against lung cancer cells.

Inhibitory effect of brassinin on TNF‑α‑induced vascular inflammation in human umbilical vein endothelial cells

Brassinin, a phytoalexin firstly identified as a constituent of Chinese cabbage, has been demonstrated to exhibit antiproliferative effects on various cancer cell lines, by reducing reactive oxygen species (ROS) production via regulation of the antioxidant pathway. The present study aimed to explore the protective effects of brassinin in TNF‑α‑induced vascular inflammation in human umbilical vein endothelial cells (HUVECs). Pretreatment with brassinin significantly inhibited adhesion of U937 cells to TNF‑α‑induced HUVECs in a dose‑dependent manner. Brassinin treatment decreased the expression levels of cell adhesion molecules, including intracellular adhesion molecule‑1 (ICAM‑1), vascular cell adhesion molecule‑1 (VCAM‑1), and endothelial‑selectin (E‑selectin) following stimulation with TNF‑α in HUVECs. In addition, pretreatment with brassinin decreased the protein expression levels of nuclear factor (NF)‑κB p65 in the nucleus, suggesting that brassinin inhibited NF‑κB p65 nuclear translocation. Brassinin treatment also markedly decreased the mRNA expression levels of interleukin‑8 in a dose‑dependent manner. Finally, brassinin pretreatment significantly decreased TNF‑α‑induced intracellular reactive oxygen species (ROS) production in HUVECs compared with control. The present results therefore suggest that brassinin may serve as a potential therapeutic agent for atherosclerosis.

Antiproliferative Effect of Indole Phytoalexins

Indole phytoalexins from crucifers have been shown to exhibit significant anti-cancer, chemopreventive, and antiproliferative activity. Phytoalexins are natural low molecular antimicrobial compounds that are synthesized and accumulated in plants after their exposure to pathogenic microorganisms. Most interestingly, crucifers appear to be the only plant family producing sulfur-containing indole phytoalexins. The mechanisms underlying its anti-cancer properties are unknown. Isolation from cruciferous plants does not provide sufficient quantities of indole phytoalexins and, for biological screening, they are usually obtainable through synthesis. Understanding the molecular mechanism of the action of these substances and their structure-activity relationships is quite important in the development of new analogs with a more favorable profile of biological activities. In this review, we present the key features of indole phytoalexins, mainly their antiproliferative ativities.

Capsaicin mediates caspases activation and induces apoptosis through P38 and JNK MAPK pathways in human renal carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is one of the tumors most refractory to chemotherapy to date. Therefore, novel therapeutic agents are urgently needed for this disease. Capsaicin (CPS), a natural active ingredient of green and red peppers, and a ligand of transient receptor potential vanilloid type 1 (TRPV1), has been showed potential in suppression of tumorigenesis of several cancers. Nonetheless, the anti-cancer activity of CPS has never been studied in human RCC.

METHODS

CCK8 analysis, LDH release activity and ROS generation analysis, flow cytometry analysis, and nuclear staining test were performed to test the influence of CPS in cultured cells in vitro, meanwhile western blot was done to uncover the precise molecular mechanisms. 786-O renal cancer xenografts were builded to investigate the antitumor activity of CPS in vivo.

RESULTS

We found treatment of CPS reduced proliferation of renal carcinoma cells, which could be attenuated by TRPV1 representative antagonist capsazepine (CPZ). CPS induced obvious apoptosis in renal carcinoma cells. These events were associated with substantial up-regulation of pro-apoptotic genes including c-myc, FADD, Bax and cleaved-caspase-3, -8, and -9, while down-regulation of anti-apoptotic gene Bcl2. Besides, CPS-treatment activated P38 and JNK MAPK pathways, yet P38 and JNK inhibitors afforded protection against CPS-induced apoptosis by abolishing activation of caspase-3, -8, and -9. Furthermore, CPS significantly slowed the growth of 786-O renal cancer xenografts in vivo.

CONCLUSIONS

Such results reveal that CPS is an efficient and potential drug for management of human RCC.

Antiproliferative and apoptotic effect of Morus nigra extract on human prostate cancer cells

Background: Morus nigra L. belongs to the family Moraceae and is frequently used in traditional medicine. Numerous studies have investigated the antiproliferative effects of various extracts of different Morus species, but studies involving the in vitro cytotoxic effect of M. nigra extract are very limited. The purpose of this study was to evaluate the phenolic composition and antioxidant activity of dimethyl sulfoxide extract of M. nigra (DEM) and to investigate, for the first time, the probable cytotoxic effect in human prostate adenocarcinoma (PC-3) cells together with the mechanism involved. Methods: Total polyphenolic contents (TPC), ferric reducing antioxidant power (FRAP) and phenolic compounds of DEM were evaluated using spectrophotometric procedures and HPLC. The cytotoxic effect of DEM on PC-3 cells was revealed using the MTT assay. Mechanisms involved in the cytotoxic effect of DEM on PC-3 cells were then investigated in terms of apoptosis, mitochondrial membrane potential and cell cycle using flow cytometry, while caspase activity was investigated using luminometric analysis. Results: TPC and FRAP values were 20.7 ± 0.3 mg gallic acid equivalents and 48.8 ± 1.6 mg trolox equivalents per g sample, respectively. Ascorbic acid and chlorogenic acid were the major phenolic compounds detected at HPLC analysis. DEM arrested the cell cycle of PC-3 cells at the G₁ phase, induced apoptosis via increased caspase activity and reduced mitochondrial membrane potential. Conclusions: Our results indicate that M. nigra may be a novel candidate for the development of new natural product based therapeutic agents against prostate cancer.

Non-pungent long chain capsaicin-analogs arvanil and olvanil display better anti-invasive activity than capsaicin in human small cell lung cancers

The nutritional compound capsaicin inhibits the invasion of many types of human cancers. The clinical development of capsaicin as an anti-cancer drug is limited due to its unfavorable side effects like burning sensation, stomach cramps, gut pain and nausea. This study compared the anti-invasive activity of capsaicin to non-pungent long chain capsaicin analogs, namely arvanil and olvanil, in human small cell lung cancer cells. Boyden chamber invasion assays revealed that arvanil and olvanil displayed improved anti-invasive activity relative to capsaicin in human SCLC cells. The results of the Boyden chamber assay were confirmed by the spherical invasion assay, and similar results were obtained. The anti-invasive activity of arvanil, olvanil and capsaicin were independent of TRPV and CB1 receptors. Furthermore, the anti-invasive activity of arvanil, olvanil and capsaicin was mediated by the AMPK pathway. Depletion of AMPK levels by siRNA methodology abrogated the anti-invasive activity of arvanil, olvanil and capsaicin. The non-pungent capsaicin analogs arvanil and olvanil display improved anti-invasive activity relative to capsaicin in human SCLC cells. These agents may represent the second generation of capsaicin-like compounds which are more potent than the parent molecule and have a better side effect profile.