Calebin A Potentiates the Effect of 5-FU and TNF-β (Lymphotoxin α) against Human Colorectal Cancer Cells: Potential Role of NF-κB

Calebin A attenuated inflammation in RAW264.7 macrophages and adipose tissue to improve hepatic glucose metabolism and hyperglycemia in high-fat diet-fed obese mice

The increased incidence of obesity, which become a global health problem, requires more functional food products with minor side and excellent effects. Calebin A (CbA) is a non-curcuminoid compound, which is reported to be an effective treatment for lipid metabolism and thermogenesis. However, its ability and mechanism of action in improving obesity-associated hyperglycemia remain unclear. This study was designed to explore the effect and mechanism of CbA in hyperglycemia via improvement of inflammation and glucose metabolism in the adipose tissue and liver in high-fat diet (HFD)-fed mice. After 10 weeks fed HFD, obese mice supplemented with CbA (25 and 100 mg/kg) for another 10 weeks showed a remarkable reducing adiposity and blood glucose. CbA modulated M1/M2 macrophage polarization, ameliorated inflammatory cytokines, and restored adiponectin as well as Glut 4 expression in the adipose tissue. In the in vitro study, CbA attenuated pro-inflammatory markers while upregulated anti-inflammatory IL-10 in LPS + IFNγ-generated M1 phenotype macrophages. In the liver, CbA attenuated steatosis, inflammatory infiltration, and protein levels of inflammatory TNF-α and IL-6. Moreover, CbA markedly upregulated Adiponectin receptor 1, AMPK, and insulin downstream Akt signaling to improve glycogen content and increase Glut2 protein. These findings indicated that CbA may be a novel therapeutic approach to treat obesity and hyperglycemia phenotype targeting on adipose inflammation and hepatic insulin signaling.

Effect of Calebin-A on Critical Genes Related to NAFLD: A Protein-Protein Interaction Network and Molecular Docking Study

Background

Calebin-A is a minor phytoconstituent of turmeric known for its activity against inflammation, oxidative stress, cancerous, and metabolic disorders like Non-alcoholic fatty liver disease(NAFLD). Based on bioinformatic tools. Subsequently, the details of the interaction of critical proteins with Calebin-A were investigated using the molecular docking technique.

Methods

We first probed the intersection of genes/ proteins between NAFLD and Calebin-A through online databases. Besides, we performed an enrichment analysis using the ClueGO plugin to investigate signaling pathways and gene ontology. Next, we evaluate the possible interaction of Calebin-A with significant hub proteins involved in NAFLD through a molecular docking study.

Results

We identified 87 intersection genes Calebin-A targets associated with NAFLD. PPI network analysis introduced 10 hub genes (TP53, TNF, STAT3, HSP90AA1, PTGS2, HDAC6, ABCB1, CCT2, NR1I2, and GUSB). In KEGG enrichment, most were associated with Sphingolipid, vascular endothelial growth factor A (VEGFA), C-type lectin receptor, and mitogen-activated protein kinase (MAPK) signaling pathways. The biological processes described in 87 intersection genes are mostly concerned with regulating the apoptotic process, cytokine production, and intracellular signal transduction. Molecular docking results also directed that Calebin-A had a high affinity to bind hub proteins linked to NAFLD.

Conclusion

Here, we showed that Calebin-A, through its effect on several critical genes/ proteins and pathways, might repress the progression of NAFLD.

Resveratrol as sensitizer in colorectal cancer plasticity

Despite tremendous medical treatment successes, colorectal cancer (CRC) remains a leading cause of cancer deaths worldwide. Chemotherapy as monotherapy can lead to significant side effects and chemoresistance that can be linked to several resistance-activating biological processes, including an increase in inflammation, cellular plasticity, multidrug resistance (MDR), inhibition of the sentinel gene p53, and apoptosis. As a consequence, tumor cells can escape the effectiveness of chemotherapeutic agents. This underscores the need for cross-target therapeutic approaches that are not only pharmacologically safe but also modulate multiple potent signaling pathways and sensitize cancer cells to overcome resistance to standard drugs. In recent years, scientists have been searching for natural compounds that can be used as chemosensitizers in addition to conventional medications for the synergistic treatment of CRC. Resveratrol, a natural polyphenolic phytoalexin found in various fruits and vegetables such as peanuts, berries, and red grapes, is one of the most effective natural chemopreventive agents. Abundant in vitro and in vivo studies have shown that resveratrol, in interaction with standard drugs, is an effective chemosensitizer for CRC cells to chemotherapeutic agents and thus prevents drug resistance by modulating multiple pathways, including transcription factors, epithelial-to-mesenchymal transition-plasticity, proliferation, metastasis, angiogenesis, cell cycle, and apoptosis. The ability of resveratrol to modify multiple subcellular pathways that may suppress cancer cell plasticity and reversal of chemoresistance are critical parameters for understanding its anti-cancer effects. In this review, we focus on the chemosensitizing properties of resveratrol in CRC and, thus, its potential importance as an additive to ongoing treatments.

Chemotherapy-induced metastasis: molecular mechanisms and clinical therapies

Chemotherapy, the most widely accepted treatment for malignant tumors, is dependent on cell death induced by various drugs including antimetabolites, alkylating agents, mitotic spindle inhibitors, antitumor antibiotics, and hormonal anticancer drugs. In addition to causing side effects due to non-selective cytotoxicity, chemotherapeutic drugs can initiate and promote metastasis, which greatly reduces their clinical efficacy. The knowledge of how they induce metastasis is essential for developing strategies that improve the outcomes of chemotherapy. Herein, we summarize the recent findings on chemotherapy-induced metastasis and discuss the underlying mechanisms including tumor-initiating cell expansion, the epithelial-mesenchymal transition, extracellular vesicle involvement, and tumor microenvironment alterations. In addition, the use of combination treatments to overcome chemotherapy-induced metastasis is also elaborated.

Calebin A targets the HIF-1α/NF-κB pathway to suppress colorectal cancer cell migration

Background: Hypoxia-inducible factor-1α (HIF-1α) is one of the major tumor-associated transcription factors modulating numerous tumor properties such as tumor cell metabolism, survival, proliferation, angiogenesis, and metastasis. Calebin A (CA), a compound derived from turmeric, is known for its anti-cancer activity through modulation of the NF-κB pathway. However, its impact on HIF-1α in colorectal cancer (CRC) cell migration is unknown. Methods: Human CRC cells (HCT-116) in 3D alginate and monolayer multicellular TME (fibroblasts/T lymphocytes) were subjected to CA or the HIF-1α inhibitor to explore the efficacy of CA on TME-induced inflammation, migration, and tumor malignancy. Results: CA significantly inhibited TME-promoted proliferation and migration of HCT-116 cells, similar to the HIF-1α inhibitor. Colony formation, toluidine blue staining, and immunolabeling showed that CA inhibited the migration of HCT-116 cells partly by inhibiting HIF-1α, which is critical for CRC cell viability, and these observations were confirmed by electron microscopy. In addition, Western blot analysis confirmed that CA inhibited TME-initiated expression of HIF-1α and biomarkers of metastatic factors (such as NF-κB, β1-integrin, and VEGF), and promoted apoptosis (caspase-3), in a manner comparable to the HIF-1α inhibitor. Finally, TME induced a purposeful pairing between HIF-1α and NF-κB, suggesting that the synergistic interplay between the two tumor-associated transcription factors is essential for CRC cell malignancy and migration and that CA silences these factors in tandem. Conclusion: These results shed light on a novel regulatory modulation of CA signaling in CRC cell migration, partially via HIF-1α/NF-κB with potentially relevant implications for cancer therapy.

Augmentation of Docetaxel-Induced Cytotoxicity in Human PC-3 Androgen-Independent Prostate Cancer Cells by Combination With Four Natural Apoptosis-Inducing Anticancer Compounds

Docetaxel (DTX) is the treatment of choice for metastatic castration-resistant prostate cancer. However, developing drug resistance is a significant challenge for achieving effective therapy. This study evaluated the anticancer and synergistic effects on DTX of four natural compounds (calebin A, 3^'-hydroxypterostilbene, hispolon, and tetrahydrocurcumin) using PC-3 androgen-resistant human prostate cancer cells. We utilized the CellTiter-Glo^® luminescent cell viability assay and human PC-3 androgen-independent prostate cancer cells to determine the antiproliferative effects of the four compounds alone and combined with DTX. Cytotoxicity to normal human prostate epithelial cells was tested in parallel using normal immortalized human prostate epithelial cells (RWPE-1). We used cell imaging and quantitative caspase-3 activity to determine whether these compounds induce apoptosis. We also measured the capacity of each drug to inhibit TNF-α-induced NF-kB using a colorimetric assay. Our results showed that all four natural compounds significantly augmented the toxicity of DTX to androgen-resistant PC-3 prostate cancer cells at IC₅₀. Interestingly, when used alone, each of the four compounds had a higher cytotoxic activity to PC-3 than DTX. Mechanistically, these compounds induced apoptosis, which we confirmed by cell imaging and caspase-3 colorimetric assays. Further, when used either alone or combined with DTX, the four test compounds inhibited TNF-α-induced NF-kB production. More significantly, the cytotoxic effects on normal immortalized human prostate epithelial cells were minimal and non-significant, suggesting prostate cancer-specific effects. In conclusion, the combination of DTX with the four test compounds could effectively enhance the anti-prostate cancer activity of DTX. This combination has the added value of reducing the DTX effective concentration. We surmise that calebin A, 3^'-hydroxypterostilbene, hispolon, and tetrahydrocurcumin were all excellent drug candidates that produced significant antiproliferative activity when used alone and synergistically enhanced the anticancer effect of DTX. Further in vivo studies using animal models of prostate cancer are needed to confirm our in vitro findings.

Targeting Autophagy Using Long Non-Coding RNAs (LncRNAs): New Landscapes in the Arena of Cancer Therapeutics

Cancer has become a global health hazard accounting for 10 million deaths in the year 2020. Although different treatment approaches have increased patient overall survival, treatment for advanced stages still suffers from poor clinical outcomes. The ever-increasing prevalence of cancer has led to a reanalysis of cellular and molecular events in the hope to identify and develop a cure for this multigenic disease. Autophagy, an evolutionary conserved catabolic process, eliminates protein aggregates and damaged organelles to maintain cellular homeostasis. Accumulating evidence has implicated the deregulation of autophagic pathways to be associated with various hallmarks of cancer. Autophagy exhibits both tumor-promoting and suppressive effects based on the tumor stage and grades. Majorly, it maintains the cancer microenvironment homeostasis by promoting viability and nutrient recycling under hypoxic and nutrient-deprived conditions. Recent investigations have discovered long non-coding RNAs (lncRNAs) as master regulators of autophagic gene expression. lncRNAs, by sequestering autophagy-related microRNAs, have been known to modulate various hallmarks of cancer, such as survival, proliferation, EMT, migration, invasion, angiogenesis, and metastasis. This review delineates the mechanistic role of various lncRNAs involved in modulating autophagy and their related proteins in different cancers.

The Journey of Resveratrol from Vineyards to Clinics

With rising technological advancements, several factors influence the lifestyle of people and stimulate chronic inflammation that severely affects the human body. Chronic inflammation leads to a broad range of physical and pathophysiological distress. For many years, non-steroidal drugs and corticosteroids were most frequently used in treating inflammation and related ailments. However, long-term usage of these drugs aggravates the conditions of chronic diseases and is presented with morbid side effects, especially in old age. Hence, the quest for safe and less toxic anti-inflammatory compounds of high therapeutic potential with least adverse side effects has shifted researchers' attention to ancient medicinal system. Resveratrol (RSV) - 3,4,5^' trihydroxystilbene is one such naturally available polyphenolic stilbene derivative obtained from various plant sources. For over 2000 years, these plants have been used in Asian medicinal system for curing inflammation-associated disorders. There is a wealth of in vitro, in vivo and clinical evidence that shows RSV could induce anti-aging health benefits including, anti-cancer, anti-inflammatory, anti-oxidant, phytoesterogenic, and cardio protective properties. However, the issue of rapid elimination of RSV through the metabolic system and its low bio-availability is of paramount importance which is being studied extensively. Therefore, in this article, we scientifically reviewed the molecular targets, biological activities, beneficial and contradicting effects of RSV as evinced by clinical studies for the prevention and treatment of inflammation-mediated chronic disorders.

Modulation of diverse oncogenic signaling pathways by oroxylin A: An important strategy for both cancer prevention and treatment

BACKGROUND

Regardless of major advances in diagnosis, prevention and treatment strategies, cancer is still a foreboding cause due to factors like chemoresistance, radioresistance, adverse side effects and cancer recurrence. Therefore, continuous development of unconventional approaches is a prerequisite to overcome foregoing glitches. Natural products have found their way into treatment of serious health conditions, including cancer since ancient times. The compound oroxylin A (OA) is one among those with enormous potential against different malignancies. It is a flavonoid obtained from the several plants such as Oroxylum indicum, Scutellaria baicalensis and S. lateriflora, Anchietea pyrifolia, and Aster himalaicus.

PURPOSE

The main purpose of this study is to comprehensively elucidate the anticancerous effects of OA against various malignancies and unravel their chemosensitization and radiosensitization potential. Pharmacokinetic and pharmacodynamic studies of OA have also been investigated.

METHOD

The literature on antineoplastic effects of OA was searched in PubMed and Scopus, including in vitro and in vivo studies and is summarized based on a systematic review protocol prepared according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The term "oroxylin A" was used in combination with "cancer" and all the title, abstracts and keywords appeared were considered.

RESULTS

In Scopus, a total of 157 articles appeared out of which 103 articles that did not meet the eligibility criteria were eliminated and 54 were critically evaluated. In PubMed, from the 85 results obtained, 26 articles were eliminated and 59 were included in the preparation of this review. Mounting number of studies have illustrated the anticancer effects of OA, and its mechanism of action.

CONCLUSION

OA is a promising natural flavonoid possessing wide range of pleiotropic properties and is a potential anticancer agent. It has a great potential in the treatment of multiple cancers including brain, breast, cervical, colon, esophageal, gall bladder, gastric, hematological, liver, lung, oral, ovarian, pancreatic and skin. However, lack of pharmacokinetic studies, toxicity assessments, and dose standardization studies and adverse effects limit the optimization of this compound as a therapeutic agent.

Multifunctionality of Calebin A in inflammation, chronic diseases and cancer

Chronic diseases including cancer have high case numbers as well as mortality rates. The efficient treatment of chronic diseases is a major ongoing medical challenge worldwide, because of their complexity and many inflammatory pathways such as JNK, p38/MAPK, MEK/ERK, JAK/STAT3, PI3K and NF-κB among others being implicated in their pathogenesis. Together with the versatility of chronic disease classical mono-target therapies are often insufficient. Therefore, the anti-inflammatory as well as anti-cancer capacities of polyphenols are currently investigated to complement and improve the effect of classical anti-inflammatory drugs, chemotherapeutic agents or to overcome drug resistance of cancer cells. Currently, research on Calebin A, a polyphenolic component of turmeric (Curcuma longa), is becoming of growing interest with regard to novel treatment strategies and has already been shown health-promoting as well as anti-tumor properties, including anti-oxidative and anti-inflammatory effects, in diverse cancer cells. Within this review, we describe already known anti-inflammatory activities of Calebin A via modulation of NF-κB and its associated signaling pathways, linked with TNF-α, TNF-β and COX-2 and further summarize Calebin A's tumor-inhibiting properties that are known up to date such as reduction of cancer cell viability, proliferation as well as metastasis. We also shed light on possible future prospects of Calebin A as an anti-cancer agent.

Evidence That β1-Integrin Is Required for the Anti-Viability and Anti-Proliferative Effect of Resveratrol in CRC Cells

The β1-integrin receptor is broadly expressed on tumor and other cells in the tumor microenvironment (TME), and is an unfavorable prognostic factor for cancers. Nature-derived resveratrol has preventive and apoptotic effects on tumors, but whether resveratrol can exert its suppressive actions on TME-induced tumorigenesis through β1-integrin on the surface of CRC cells is still unknown. HCT116 or SW480 cells were exposed to inhibitory antibodies against β1-integrin, bacitracin (selective β1-integrin inhibitor), integrin-binding RGD (Arg-Gly-Asp) peptide, and/or resveratrol. We evaluated the anti-tumor actions and signaling impacts of resveratrol in colorectal cancer (CRC)-TME. We found that resveratrol completely altered the β1-integrin distribution pattern and expression on the surface of CRC cells in TME. Moreover, resveratrol down-regulated CRC cell proliferation, colony formation, viability, and up-regulated apoptosis in a concentration-dependent way. These actions of resveratrol were antagonized mainly by inhibitory antibodies against β1-integrin but not β5-integrin, and by an integrin-binding RGD peptide but not by RGE peptide, and by bacitracin in TME. Similarly, resveratrol-blocked TME-induced p65-NF-kB and its promoted gene markers linked to proliferation (cyclin D1), invasion (focal adhesion kinase, FAK), or apoptosis (caspase-3), were largely abrogated by anti-β1-integrin or RGD peptide, suggesting that β1-integrin is a potential transmission pathway for resveratrol/integrin down-stream signaling in CRC cells. The current results highlight, for the first time, the important gateway role of β1-integrins as signal carriers for resveratrol on the surfaces of HCT116 and SW480 cells, and their functional cooperation for the modulatory effects of resveratrol on TME-promoted tumorigenesis.

Bacteria-Mediated Modulatory Strategies for Colorectal Cancer Treatment

Colorectal cancer (CRC) is one of the most common tumors worldwide, with a higher rate of distant metastases than other malignancies and with regular occurrence of drug resistance. Therefore, scientists are forced to further develop novel and innovative therapeutic treatment strategies, whereby it has been discovered microorganisms, albeit linked to CRC pathogenesis, are able to act as highly selective CRC treatment agents. Consequently, researchers are increasingly focusing on bacteriotherapy as a novel therapeutic strategy with less or no side effects compared to standard cancer treatment methods. With multiple successful trials making use of various bacteria-associated mechanisms, bacteriotherapy in cancer treatment is on its way to become a promising tool in CRC targeting therapy. In this study, we describe the anti-cancer effects of bacterial therapy focusing on the treatment of CRC as well as diverse modulatory mechanisms and techniques that bacteriotherapy offers such as bacterial-related biotherapeutics including peptides, toxins, bacteriocins or the use of bacterial carriers and underlying molecular processes to target colorectal tumors.

Modulation of TLR/NF-κB/NLRP Signaling by Bioactive Phytocompounds: A Promising Strategy to Augment Cancer Chemotherapy and Immunotherapy

Background

Tumors often progress to a more aggressive phenotype to resist drugs. Multiple dysregulated pathways are behind this tumor behavior which is known as cancer chemoresistance. Thus, there is an emerging need to discover pivotal signaling pathways involved in the resistance to chemotherapeutic agents and cancer immunotherapy. Reports indicate the critical role of the toll-like receptor (TLR)/nuclear factor-κB (NF-κB)/Nod-like receptor pyrin domain-containing (NLRP) pathway in cancer initiation, progression, and development. Therefore, targeting TLR/NF-κB/NLRP signaling is a promising strategy to augment cancer chemotherapy and immunotherapy and to combat chemoresistance. Considering the potential of phytochemicals in the regulation of multiple dysregulated pathways during cancer initiation, promotion, and progression, such compounds could be suitable candidates against cancer chemoresistance.

Objectives

This is the first comprehensive and systematic review regarding the role of phytochemicals in the mitigation of chemoresistance by regulating the TLR/NF-κB/NLRP signaling pathway in chemotherapy and immunotherapy.

Methods

A comprehensive and systematic review was designed based on Web of Science, PubMed, Scopus, and Cochrane electronic databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to include papers on TLR/NF-κB/NLRP and chemotherapy/immunotherapy/chemoresistance by phytochemicals.

Results

Phytochemicals are promising multi-targeting candidates against the TLR/NF-κB/NLRP signaling pathway and interconnected mediators. Employing phenolic compounds, alkaloids, terpenoids, and sulfur compounds could be a promising strategy for managing cancer chemoresistance through the modulation of the TLR/NF-κB/NLRP signaling pathway. Novel delivery systems of phytochemicals in cancer chemotherapy/immunotherapy are also highlighted.

Conclusion

Targeting TLR/NF-κB/NLRP signaling with bioactive phytocompounds reverses chemoresistance and improves the outcome for chemotherapy and immunotherapy in both preclinical and clinical stages.

Pre-Administration of Berberine Exerts Chemopreventive Effects in AOM/DSS-Induced Colitis-Associated Carcinogenesis Mice via Modulating Inflammation and Intestinal Microbiota

Inflammatory activation and intestinal flora imbalance play an essential role in the development and progression of colorectal cancer (CRC). Berberine (BBR) has attracted great attention in recent years due to its heath-related benefits in inflammatory disorders and tumors, but the intricate mechanisms have not been fully elucidated. In this study, the effects and the mechanism of BBR on colon cancer were investigated in an azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colitis-associated carcinogenesis mice model. Our results showed that pre-administration of BBR showed a decrease in weight loss, disease activity index (DAI) score, and the number of colon tumors in mice, compared with the model group. The evidence from pathological examination indicated that the malignancy of intestinal tumors was ameliorated after pre-administration of BBR. Additionally, pre-administration with BBR suppressed the expression of pro-inflammatory factors (interleukin (IL)-6, IL-1β, cyclooxygenase (COX)-2 and tumor necrosis factor (TNF)-α) and the cell-proliferation marker Ki67, while expression of the tight junction proteins (ZO-1 and occludin) were increased in colon tissue. Moreover, the levels of critical pathway proteins involved in the inflammatory process (p-STAT3 and p-JNK) and cell cycle regulation molecules (β-catenin, c-Myc and CylinD1) exhibited lower expression levels. Besides, 16S rRNA sequence analysis indicated that pre-administration of BBR increased the ratio of Firmicutes/Bacteroidetes (F:M) and the relative abundance of potentially beneficial bacteria, while the abundance of cancer-related bacteria was decreased. Gavage with Lactobacillus rhamnosus can improve the anti-tumor effect of BBR. Overall, pre-administration of BBR exerts preventive effects in colon carcinogenesis, and the mechanisms underlying these effects are correlated with the inhibition of inflammation and tumor proliferation and the maintenance of intestinal homeostasis.

KIF15 knockdown suppresses gallbladder cancer development

Gallbladder cancer (GBC) is commonly regarded as one of the most lethal malignant tumor types with poor prognosis. Kinesin family member 15 (KIF15) is reported to be tightly related with progression of multiple cancer types which, however, has not been clarified in GBC so far. KIF15 was significantly up-regulated in clinical GBC tissues compared with that in para-carcinoma tissues and the expression level was also correlated with tumor malignancies. In addition to tissues, GBC cells also exhibited a high expression abundance of KIF15. After down-regulating KIF15 via lentiviral transfection, GBC cell proliferation and migration were both inhibited, while cell apoptosis was promoted markedly. Likewise, silencing KIF15 significantly interfered the growth of nude mouse xenografts. Our experiments in GBC cell lines also demonstrated that KIF15 overexpression accelerated cell proliferation but lessened cell apoptosis in both GBC-SD and SGC-996 cells. Further investigation of the mechanism occurring in GBC inhibition mediated by KIF15 knockdown revealed that KIF15 deficiency led to decreased activity of several signaling pathways (TNF, PI3K/AKT and MAPK), a reduction of CDK6 expression regulated by enhanced p21, and HSP60 absence. Following the treatment of shCtrl- and shKIF15-transfected cells with AKT activator, we found that anti-tumor effects resulting from KIF15 deficiency could be relieved by AKT activator in both experimental cells. Overall, for the first time, we demonstrated that KIF15 was overexpressed in GBC and displayed a close relationship between KIF15 levels and GBC clinical stages. Furthermore, low expression of KIF15 resulted in obvious anti-tumor effects.

Multitargeting Effects of Calebin A on Malignancy of CRC Cells in Multicellular Tumor Microenvironment

Background

Tumor microenvironment (TME) provides the essential prerequisite niche for promoting cancer progression and metastasis. Calebin A, a component of Curcuma longa, has long been investigated as a safe multitargeted agent with antitumor and anti-inflammatory properties. However, the multicellular-TME-induced malignancy and the antitumorigenic potential of Calebin A on colorectal cancer (CRC) cells in 3D-alginate cultures are not yet understood, and more in-depth research is needed.

Methods

3D-alginate tumor cultures (HCT116 cells) in the multicellular proinflammatory TME (fibroblast cells/T lymphocytes), tumor necrosis factor beta (TNF-β)-TME (fibroblast cells/TNF-β) were treated with/without Calebin A to address the pleiotropic actions of Calebin A in the CRC.

Results

We found that Calebin A downmodulated proliferation, vitality, and migration of HCT116 cells in 3D-alginate cultures in multicellular proinflammatory TME or TNF-β-TME. In addition, Calebin A suppressed TNF-β-, similar to multicellular-TME-induced phosphorylation of nuclear factor kappa B (NF-κB) in a concentration-dependent manner. NF-κB-promoting proinflammatory mediators, associated with tumor growth and antiapoptotic molecules (i.e.,MMP-9, CXCR4, Ki-67, β1-integrin, and Caspase-3) and its translocation to the nucleus in HCT116 cells, were increased in both TME cultures. The multicellular-TME cultures further induced the survival of cancer stem cells (CSCs) (upregulation of CD133, CD44, and ALDH1). Last but not the least, Calebin A suppressed multicellular-, similar to TNF-β-TME-induced rigorous upregulation of NF-κB phosphorylation, various NF-κB-regulated gene products, CSCs activation, and survival in 3D-alginate tumor cultures.

Conclusions

The downmodulation of multicellular proinflammatory-, similar to TNF-β-TME-induced CRC proliferation, survival, and migration by the multitargeting agent Calebin A could be a new therapeutic strategy to suppress inflammation and CRC tumorigenesis.

Chemical Characterization of Sambucus nigra L. Flowers Aqueous Extract and Its Biological Implications

The main goal of this study was to chemically characterize an aqueous S. nigra flower extract and validate it as a bioactive agent. The elderflower aqueous extraction was performed at different temperatures (50, 70 and 90 °C). The extract obtained at 90 °C exhibited the highest phenolic content and antiradical activity. Therefore, this extract was analyzed by GC-MS and HPLC-MS, which allowed the identification of 46 compounds, being quercetin and chlorogenic acid derivatives representative of 86% of the total of phenolic compounds identified in hydrophilic fraction of the aqueous extract. Naringenin (27.2%) was the major compound present in the lipophilic fraction. The antiproliferative effects of the S. nigra extract were evaluated using the colon cancer cell lines RKO, HCT-116, Caco-2 and the extract’s antigenotoxic potential was evaluated by the Comet assay in RKO cells. The RKO cells were the most susceptible to S. nigra flower extract (IC₅₀ = 1250 µg mL⁻¹). Moreover, the extract showed antimicrobial activity against Gram-positive bacteria, particularly Staphylococcus aureus and S. epidermidis. These results show that S. nigra-based extracts can be an important dietary source of bioactive phenolic compounds that contribute to health-span improving life quality, demonstrating their potential as nutraceutical, functional foods and/or cosmetic components for therapeutic purposes.

Curcumin Attenuates Environment-Derived Osteoarthritis by Sox9/NF-kB Signaling Axis

Inflammation has a fundamental impact on the pathophysiology of osteoarthritis (OA), a common form of degenerative arthritis. It has previously been established that curcumin, a component of turmeric (Curcuma longa), has anti-inflammatory properties. This research evaluates the potentials of curcumin on the pathophysiology of OA in vitro. To explore the anti-inflammatory efficacy of curcumin in an inflamed joint, an osteoarthritic environment (OA-EN) model consisting of fibroblasts, T-lymphocytes, 3D-chondrocytes is constructed and co-incubated with TNF-α, antisense oligonucleotides targeting NF-kB (ASO-NF-kB), or an IkB-kinase (IKK) inhibitor (BMS-345541). Our results show that OA-EN, similar to TNF-α, suppresses chondrocyte viability, which is accompanied by a significant decrease in cartilage-specific proteins (collagen II, CSPG, Sox9) and an increase in NF-kB-driven gene proteins participating in inflammation, apoptosis, and breakdown (NF-kB, MMP-9, Cox-2, Caspase-3). Conversely, similar to knockdown of NF-kB at the mRNA level or at the IKK level, curcumin suppresses NF-kB activation, NF-kB-promotes gene proteins derived from the OA-EN, and stimulates collagen II, CSPG, and Sox9 expression. Furthermore, co-immunoprecipitation assay shows that curcumin reduces OA-EN-mediated inflammation and chondrocyte apoptosis, with concomitant chondroprotective effects, due to modulation of Sox-9/NF-kB signaling axis. Finally, curcumin selectively hinders the interaction of p-NF-kB-p65 directly with DNA—this association is disrupted through DTT. These results suggest that curcumin suppresses inflammation in OA-EN via modulating NF-kB-Sox9 coupling and is essential for maintaining homeostasis in OA by balancing chondrocyte survival and inflammatory responses. This may contribute to the alternative treatment of OA with respect to the efficacy of curcumin.

Targeting Farnesoid X receptor (FXR) for developing novel therapeutics against cancer

Cancer is one of the lethal diseases that arise due to the molecular alterations in the cell. One of those alterations associated with cancer corresponds to differential expression of Farnesoid X receptor (FXR), a nuclear receptor regulating bile, cholesterol homeostasis, lipid, and glucose metabolism. FXR is known to regulate several diseases, including cancer and cardiovascular diseases, the two highly reported causes of mortality globally. Recent studies have shown the association of FXR overexpression with cancer development and progression in different types of cancers of breast, lung, pancreas, and oesophagus. It has also been associated with tissue-specific and cell-specific roles in various cancers. It has been shown to modulate several cell-signalling pathways such as EGFR/ERK, NF-κB, p38/MAPK, PI3K/AKT, Wnt/β-catenin, and JAK/STAT along with their targets such as caspases, MMPs, cyclins; tumour suppressor proteins like p53, C/EBPβ, and p-Rb; various cytokines; EMT markers; and many more. Therefore, FXR has high potential as novel biomarkers for the diagnosis, prognosis, and therapy of cancer. Thus, the present review focuses on the diverse role of FXR in different cancers and its agonists and antagonists.

Xanthohumol from Hop: Hope for cancer prevention and treatment

Cancer is a major public health concern due to high mortality and poor quality of life of patients. Despite the availability of advanced therapeutic interventions, most treatment modalities are not efficacious, very expensive, and cause several adverse side effects. The factors such as drug resistance, lack of specificity, and low efficacy of the cancer drugs necessitate developing alternative strategies for the prevention and treatment of this disease. Xanthohumol (XN), a prenylated chalcone present in Hop (Humulus lupulus), has been found to possess prominent activities against aging, diabetes, inflammation, microbial infection, and cancer. Thus, this manuscript thoroughly reviews the literature on the anti-cancer properties of XN and its various molecular targets. XN was found to exert its inhibitory effect on the growth and proliferation of cancer cells via modulation of multiple signaling pathways such as Akt, AMPK, ERK, IGFBP2, NF-κB, and STAT3, and also modulates various proteins such as Notch1, caspases, MMPs, Bcl-2, cyclin D1, oxidative stress markers, tumor-suppressor proteins, and miRNAs. Thus, these reports suggest that XN possesses enormous therapeutic potential against various cancers and could be potentially used as a multi-targeted anti-cancer agent with minimal adverse effects.

Evidence That Tumor Microenvironment Initiates Epithelial-To-Mesenchymal Transition and Calebin A can Suppress it in Colorectal Cancer Cells

Background: Tumor microenvironment (TME) has a pivotal impact on tumor progression, and epithelial-mesenchymal transition (EMT) is an extremely crucial initial event in the metastatic process in colorectal cancer (CRC) that is not yet fully understood. Calebin A (an ingredient in Curcuma longa) has been shown to repress CRC tumor growth. However, whether Calebin A is able to abrogate TME-induced EMT in CRC was investigated based on the underlying pathways. Methods: CRC cell lines (HCT116, RKO) were exposed with Calebin A and/or a FAK inhibitor, cytochalasin D (CD) to investigate the action of Calebin A in TME-induced EMT-related tumor progression. Results: TME induced viability, proliferation, and increased invasiveness in 3D-alginate CRC cultures. In addition, TME stimulated stabilization of the master EMT-related transcription factor (Slug), which was accompanied by changes in the expression patterns of EMT-associated biomarkers. Moreover, TME resulted in stimulation of NF-κB, TGF-β1, and FAK signaling pathways. However, these effects were dramatically reduced by Calebin A, comparable to FAK inhibitor or CD. Finally, TME induced a functional association between NF-κB and Slug, suggesting that a synergistic interaction between the two transcription factors is required for initiation of EMT and tumor cell invasion, whereas Calebin A strongly inhibited this binding and subsequent CRC cell migration. Conclusion: We propose for the first time that Calebin A modulates TME-induced EMT in CRC cells, at least partially through the NF-κB/Slug axis, TGF-β1, and FAK signaling. Thus, Calebin A appears to be a potential agent for the prevention and management of CRC.

Radix Tetrastigma Inhibits the Non-Small Cell Lung Cancer via Bax/Bcl-2/Caspase-9/Caspase-3 Pathway

Lung cancer with high mortality is regarded as a challenging global problem with unsatisfied curative effects. Clinically, the chemotherapy drugs are often faced with side-effects and tumor resistance. Radix Tetrastigma (RT) is a traditional Chinese herb and now regarded as a kind of functional food. In this study, A549-bearing nude mice control was adopted to evaluate the anti-tumor capacity of RT. Results demonstrated that RT showed excellent anti-tumor ability with no side-effect on mice compared to chemotherapy drug (5-Fu).Further studies proved that RT down-regulated the proliferation-related proteins (PCNA, Ki67) and vascular endothelial growth factor (VEGF). Additionally, RT up-regulated the ratio of Bax/Bcl-2, which caused the over-expression of Caspase-9, leading to the activation of downstream protein caspase-3, eventually resulting in apoptosis of A549 in solid tumor. These results together suggest that RT inhibits the non-small cell lung cancer (NSCLC) via Bax/Bcl2/Caspase-9/Caspase-3 pathway. Furthermore, the anti-A549 abilities of the main flavonoid components from RT were compared, and kaempferol-3-O-rutinoside would play a role in RT's outstanding anti-NSCLC ability.

Shikonin promotes ubiquitination and degradation of cIAP1/2-mediated apoptosis and necrosis in triple negative breast cancer cells

Background

Shikonin (SKO) is a natural naphthoquinone derived from Chinese herbal medicine Arnebiae Radix with high development potentials due to its anti-inflammatory and anti-tumor activities. Overwhelming evidences have indicated that SKO can induce both necrosis and apoptosis in cancer cells, while the mechanisms for triple negative breast cancer cells is still need to be disclosed.

Methods

In this study, kinds of molecular biological technologies, including flow-cytometry, Western blot, immunoprecipitation, enzyme-linked immunosorbent assay (ELISA) as well as real-time quantitative PCR (RT-qPCR), were applied for investigation on the underlying mechanisms of SKO induced necrosis and apoptosis for MDA-MB-231 cells. Inhibitors were also used for validation ofthe key signaling pathways involved in SKO triggered necrosis and apoptosis.

Results

We found that SKO significantly triggered necrosis and apoptosis of MDA-MB-231 cells in both a concentration- and time-dependent manner. Mechanism studies demonstrated that SKO significantly promoted the autoubiquitination levels and facilitated the proteasome dependent degradation of cellular inhibitor of apoptosis protein 1 (cIAP1) and cIAP2 in MDA-MB-231 cells. Autoubiquitination and degradation of cIAP1 and cIAP2 induced by SKO further led to significant decreased ubiquitination and inactivation of RIP1, which played an important role in inhibition of pro-survival and accelerating of necrosis of MDA-MB-231 cells. Treatment with proteasome inhibitor lactacystin significantly rescued the cell viability induced by treatment of SKO.

Conclusions

Our results demonstrate that SKO promotes the autoubiquitination and degradation of cIAP1 and cIAP2, which further induces the decrease of the ubiquitination of RIP1 to inhibit the activation of pro-survival signaling pathways and accelerate the necrosis of MDA-MB-231 cells. The disclosed mechanisms of SKO induced necrosis and apoptosis in our study is firstly reported, and it is believed that SKO could be considered as a potential candidate and further developed for the treatment of triple negative breast cancer.

Rationalizing the therapeutic potential of apigenin against cancer

BACKGROUND

Despite the remarkable advances made in the diagnosis and treatment of cancer during the past couple of decades, it remains the second largest cause of mortality in the world, killing approximately 9.6 million people annually. The major challenges in the treatment of the advanced stage of this disease are the development of chemoresistance, severe adverse effects of the drugs, and high treatment cost. Therefore, the development of drugs that are safe, efficacious, and cost-effective remains a 'Holy Grail' in cancer research. However, the research over the past four decades shed light on the cancer-preventive and therapeutic potential of natural products and their underlying mechanism of action. Apigenin is one such compound, which is known to be safe and has significant potential in the prevention and therapy of this disease.

AIM

To assess the literature available on the potential of apigenin and its analogs in modulating the key molecular targets leading to the prevention and treatment of different types of cancer.

METHOD

A comprehensive literature search has been carried out on PubMed for obtaining information related to the sources and analogs, chemistry and biosynthesis, physicochemical properties, biological activities, bioavailability and toxicity of apigenin.

KEY FINDINGS

The literature search resulted in many in vitro, in vivo and a few cohort studies that evidenced the effectiveness of apigenin and its analogs in modulating important molecular targets and signaling pathways such as PI3K/AKT/mTOR, JAK/STAT, NF-κB, MAPK/ERK, Wnt/β-catenin, etc., which play a crucial role in the development and progression of cancer. In addition, apigenin was also shown to inhibit chemoresistance and radioresistance and make cancer cells sensitive to these agents. Reports have further revealed the safety of the compound and the adaptation of nanotechnological approaches for improving its bioavailability.

SIGNIFICANCE

Hence, the present review recapitulates the properties of apigenin and its pharmacological activities against different types of cancer, which warrant further investigation in clinical settings.

Curcumin, a traditional spice component, can hold the promise against COVID-19?

The severity of the recent pandemic and the absence of any specific medication impelled the identification of existing drugs with potential in the treatment of Coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Curcumin, known for its pharmacological abilities especially as an anti-inflammatory agent, can be hypothesized as a potential candidate in the therapeutic regimen. COVID-19 has an assorted range of pathophysiological consequences, including pulmonary damage, elevated inflammatory response, coagulopathy, and multi-organ damage. This review summarizes the several evidences for the pharmacological benefits of curcumin in COVID-19-associated clinical manifestations. Curcumin can be appraised to hinder cellular entry, replication of SARS-CoV-2, and to prevent and repair COVID-19-associated damage of pneumocytes, renal cells, cardiomyocytes, hematopoietic stem cells, etc. The modulation and protective effect of curcumin on cytokine storm-related disorders are also discussed. Collectively, this review provides grounds for its clinical evaluation in the therapeutic management of SARS-CoV-2 infection.

Potential of guggulsterone, a farnesoid X receptor antagonist, in the prevention and treatment of cancer

Cancer is one of the most dreadful diseases in the world with a mortality of 9.6 million annually. Despite the advances in diagnosis and treatment during the last couple of decades, it still remains a serious concern due to the limitations associated with currently available cancer management strategies. Therefore, alternative strategies are highly required to overcome these glitches. The importance of medicinal plants as primary healthcare has been well-known from time immemorial against various human diseases, including cancer. Commiphora wightii that belongs to Burseraceae family is one such plant which has been used to cure various ailments in traditional systems of medicine. This plant has diverse pharmacological properties such as antioxidant, antibacterial, antimutagenic, and antitumor which mostly owes to the presence of its active compound guggulsterone (GS) that exists in the form of Z- and E-isomers. Mounting evidence suggests that this compound has promising anticancer activities and was shown to suppress several cancer signaling pathways such as NF-κB/ERK/MAPK/AKT/STAT and modulate the expression of numerous signaling molecules such as the farnesoid X receptor, cyclin D1, survivin, caspases, HIF-1α, MMP-9, EMT proteins, tumor suppressor proteins, angiogenic proteins, and apoptotic proteins. The current review is an attempt to summarize the biological activities and diverse anticancer activities (both in vitro and in vivo) of the compound GS and its derivatives, along with its associated mechanism against various cancers.

Resveratrol Suppresses Cross-Talk between Colorectal Cancer Cells and Stromal Cells in Multicellular Tumor Microenvironment: A Bridge between In Vitro and In Vivo Tumor Microenvironment Study

The interaction between tumor cells and the tumor microenvironment (TME) is an important process for the development of tumor malignancy. Modulation of paracrine cross-talk could be a promising strategy for tumor control within the TME. The exact mechanisms of multi-targeted compound resveratrol are not yet fully understood. Whether resveratrol can modulate paracrine signal transduction-induced malignancy in the multicellular-TME of colorectal cancer cells (CRC) was investigated. An in vitro model with 3D-alginate HCT116 cells in multicellular-TME cultures (fibroblast cells, T-lymphocytes) was used to elucidate the role of TNF-β, Sirt1-ASO and/or resveratrol in the proliferation, invasion and cancer stem cells (CSC) of CRC cells. We found that multicellular-TME, similar to TNF-β-TME, promoted proliferation, colony formation, invasion of CRC cells and enabled activation of CSCs. However, after co-treatment with resveratrol, the malignancy of multicellular-TME reversed to HCT116. In addition, resveratrol reduced the secretion of T-lymphocyte/fibroblast (TNF-β, TGF-β3) proteins, antagonized the T-lymphocyte/fibroblast-promoting NF-κB activation, NF-κB nuclear translocation and thus the expression of NF-κB-promoting biomarkers, associated with proliferation, invasion and survival of CSCs in 3D-alginate cultures of HCT116 cells induced by TNF-β- or multicellular-TME, but not by Sirt1-ASO, indicating the central role of this enzyme in the anti-tumor function of resveratrol. Our results suggest that in vitro multicellular-TME promotes crosstalk between CRC and stromal cells to increase survival, migration of HCT116 and the resveratrol/Sirt1 axis suppresses this loop by modulating paracrine agent secretion and NF-κB signaling. Fibroblasts and T-lymphocytes are promising targets for resveratrol in the prevention of CRC metastasis.

Inhibition of semaphorin 4D enhances chemosensitivity by increasing 5-fluorouracile-induced apoptosis in colorectal cancer cells

Overexpression of semaphorin 4D (SEMA4D), an immune semaphorin, is found in various human malignancies, including colorectal cancer (CRC). In this study, we explored the relationship between silencing SEMA4D expression and 5-fluorouracil (5-FU) response in the colorectal cancer cell line. SW48 cells were transfected with a short interfering RNA (siRNA) in order to silence SEMA4D gene expression and then exposed to 5-FU for 48 h. The down-regulation of SEMA4D expression was confirmed by qRT-PCR and the particular concentration of 5-FU was acquired using MTT assay. Flow cytometry and western blot were used to evaluate apoptosis rate and pro- and anti-apoptotic expression levels of proteins involved in apoptosis including Bax, Bcl-2, P53, and caspase-3. Other oncogenic activities including epithelial-mesenchymal transition (EMT) process, cancer stem cell (CSC) markers, and β-catenin pathway were investigated using qRT-PCR, and western blot. The proliferation was analyzed via colony formation test and cell invasion was assessed by transwell assay. Our data demonstrate that SEMA4D silencing results in strikingly elevated apoptosis in response to 5-FU treatment and leads to down-regulation of Bcl-2 and overexpression of Bax, P53, and caspase-3 in protein levels. Furthermore, the mRNA and protein expression levels of β-catenin, as well as transcript expressions of CSCs and EMT markers, were remarkably diminished. However, mRNA expression of E-cadherin as an epithelial marker was significantly increased in 5-FU treatment combined with siRNA SEMA4D. This study implicates that the silencing of SEMA4D by siRNA promotes the chemosensitivity of SW48 cells to 5-FU and it may be a potential therapeutic agent for colon cancer therapy.

Targeting NF-κB Signaling by Calebin A, a Compound of Turmeric, in Multicellular Tumor Microenvironment: Potential Role of Apoptosis Induction in CRC Cells

Increasing lines of evidence suggest that chronic inflammation mediates most chronic diseases, including cancer. The transcription factor, NF-κB, has been shown to be a major regulator of inflammation and metastasis in tumor cells. Therefore, compounds or any natural agents that can inhibit NF-κB activation have the potential to prevent and treat cancer. However, the mechanism by which Calebin A, a component of turmeric, regulates inflammation and disrupts the interaction between HCT116 colorectal cancer (CRC) cells and multicellular tumor microenvironment (TME) is still poorly understood. The 3D-alginate HCT116 cell cultures in TME were treated with Calebin A, BMS-345541, and dithiothreitol (DTT) and examined for invasiveness, proliferation, and apoptosis. The mechanism of TME-induced malignancy of cancer cells was confirmed by phase contrast, Western blotting, immunofluorescence, and DNA-binding assay. We found through DNA binding assay, that Calebin A inhibited TME-induced NF-κB activation in a dose-dependent manner. As a result of this inhibition, NF-κB phosphorylation and NF-κB nuclear translocation were down-modulated. Calebin A, or IκB-kinase (IKK) inhibitor (BMS-345541) significantly inhibited the direct interaction of nuclear p65 to DNA, and interestingly this interaction was reversed by DTT. Calebin A also suppressed the expression of NF-κB-promoted anti-apoptotic (Bcl-2, Bcl-xL, survivin), proliferation (Cyclin D1), invasion (MMP-9), metastasis (CXCR4), and down-regulated apoptosis (Caspase-3) gene biomarkers, leading to apoptosis in HCT116 cells. These results suggest that Calebin A can suppress multicellular TME-promoted CRC cell invasion and malignancy by inhibiting the NF-κB-promoting inflammatory pathway associated with carcinogenesis, underlining the potential of Calebin A for CRC treatment.