Curcumin and cancer biology: Focusing regulatory effects in different signalling pathways

Effects of mesenchymal stem cells versus curcumin on sonic hedgehog signaling in experimental model of Hepatocellular Carcinoma

BACKGROUND

Sonic Hedgehog (SHH) is a fundamental signaling pathway that controls tissue reconstruction, stem cell biology, and differentiation and has a role in gut tissue homeostasis and development. Dysregulation of SHH leads to the development of HCC.

METHODS, AND RESULTS

The present study was conducted to compare the effects of mesenchymal stem cells (MSCs) and curcumin on SHH molecular targets in an experimental model of HCC in rats. One hundred rats were divided equally into the following groups: control group, HCC group, HCC group received MSCs, HCC group received curcumin, and HCC group received MSCs and curcumin. Histopathological examinations were performed, and gene expression of SHH signaling target genes (SHH, PTCH1, SMOH, and GLI1) was assessed by real-time PCR in rat liver tissue. Results showed that SHH target genes were significantly upregulated in HCC-untreated rat groups and in MSC-treated groups, with no significant difference between them. Administration of curcumin with or without combined administration of MSCs led to a significant down-regulation of SHH target genes, with no significant differences between both groups. As regards the histopathological examination of liver tissues, both curcumin and MSCs, either through separate use or their combined use, led to a significant restoration of normal liver pathology.

CONCLUSIONS

In conclusion, SHH signaling is upregulated in the HCC experimental model. MSCs do not inhibit the upregulated SHH target genes in HCC. Curcumin use with or without MSCs administration led to a significant down-regulation of SHH signaling in HCC and a significant restoration of normal liver pathology.

Wondrous Yellow Molecule: Are Hydrogels a Successful Strategy to Overcome the Limitations of Curcumin?

Curcumin is a natural compound with a great pharmaceutical potential that involves anticancer, anti-inflammatory, antioxidant, and neuroprotective activity. Unfortunately, its low bioavailability, instability, and poor water solubility significantly deteriorate its clinical use. Many attempts have been made to overcome this issue, and encapsulating curcumin in a hydrogel matrix may improve those properties. Hydrogel formulation is used in many drug delivery forms, including classic types and novel forms such as self-assembly systems or responsive to external factors. Reviewed studies confirmed better properties of hydrogel-stabilized curcumin in comparison to pure compound. The main enhanced characteristics were chemical stability, bioavailability, and water solubility, which enabled these systems to be tested for various diseases. These formulations were evaluated for wound healing properties, effectiveness in treating skin diseases, and anticancer and regenerative activity. Hydrogel formulation significantly improved biopharmaceutical properties, opening the opportunity to finally see curcumin as a clinically approved substance and unravel its therapeutic potential.

Curcuminoids as Cell Signaling Pathway Modulators: A Potential Strategy for Cancer Prevention

Despite substantial advancements in curative modern medicine in the last few decades, cancer risk and casualty rates have continued to mount globally. The exact reason for cancer's onset and progression is still unknown. However, skeletal and functional abnormalities in the genetic code are assumed to be the primary cause of cancer. Many lines of evidence reported that some medicinal plants can be utilized to curb cancer cell proliferation with a safe, fruitful, and cost-efficient perspective. Curcuminoid, isolated from Curcuma longa, have gotten a lot of focus due to their anticancer potential as they reduce tumor progression, invasion, and dissemination. Further, they modulated signal transduction routes like MAPK, PI3K/Akt/mTOR, JAK/STAT, and Wnt/β-catenin, etc., and triggered apoptosis as well as actuated autophagy in malignant cells without altering the normal cells, thus preventing cancer progression. Besides, Curcuminoid also regulate the function and expression of anti-tumor and carcinogenic miRNAs. Clinical studies also reported the therapeutic effect of Curcuminoid against various cancer through decreasing specific biomarkers like TNF-α, Bcl-2, COX-2, PGE2, VEGF, IκKβ, and various cytokines like IL-12p70, IL-10, IL-2, IFN-γ levels and increasing in p53 and Bax levels. Thus, in the present review, we abridged the modulation of several signal transduction routes by Curcuminoids in various malignancies, and its modulatory role in the initiation of tumor-suppressive miRNAs and suppression of the oncogenic miRNAs are explored. Additionally, various pharmacokinetic approaches have been projected to address the Curcuminoids bioavailability like the use of piperine as an adjuvant; nanotechnology- based Curcuminoids preparations utilizing Curcuminoids analogues are also discussed.

A co-carrier for plasmid DNA and curcumin delivery to treat pancreatic cancer via dendritic poly(l-lysine) modified amylose

Pancreatic cancer is one of the most lethal malignancies in the world and remains one of the leading causes of cancer related death. For its treatment, a lot of investigations have dealt not only with individual chemotherapy by using polymeric carriers to deliver anticancer drugs, but also with individual gene therapy by using polymeric carriers to deliver nucleic acids such as small interfering RNA (siRNA) and plasmid DNA. However, relatively few studies have been focused on the co-delivery of gene and anticancer drug by multifunctional polymeric carriers for its synergistic therapy. In this work, a DPLL-functionalized amylose (ADP) was prepared by the click reaction between azidized amylose and propargyl focal point poly(l-lysine) dendrons, and then used to co-deliver plasmid pIRES2-EGFP-TNFα and curcumin for pancreatic cancer treatment. Due to the internal hydrophobic cavity of amylose component, ADP could load efficiently curcumin with anticancer activity and showed a sustained release behavior. Moreover, the curcumin-loaded ADP could form colloidally stable nanocomplexes with plasmid DNA in aqueous system due to the existence of cationic poly(l-lysine) dendrons and exhibited high gene transfection efficiency. The in vitro and in vivo tests confirmed the effectiveness of using ADP to co-deliver plasmid pIRES2-EGFP-TNFα and curcumin for synergistic therapy of pancreatic cancer.

Curcumin inhibits malignant behavior of colorectal cancer cells by regulating M2 polarization of tumor-associated macrophages and metastasis associated in colon cancer 1 (MACC1) expression

The present study was to investigate the underlying mechanism of the antitumor effect of curcumin in colorectal cancer cells, focusing on the M2 polarization of tumor-associated macrophages (TAMs). The effect of curcumin on the malignant behavior of colorectal cancer cells was investigated by WST assay for cell growth, and Transwell assay for cell migration/invasion. THP-1 cells were differentiated into macrophages and coculture with colorectal cancer cells to study the influence of curcumin on M2 polarization, presenting as the levels of ARG1 mRNA, IL-10, and CD163-positive cells. GEO database was searched for the shared altered gene of curcumin in colorectal cells and human monocytes. Molecular docking was used to visualize the binding between curcumin and MACC1. Curcumin restricted the proliferation, apoptosis, and migration/invasion of HCT 116 and SW620 cells. Curcumin attenuated levels of the M2 macrophage markers, CD163 + cells, IL-10 secretion, and ARG1 mRNA. MACC1 was a target of curcumin in colorectal cancer cells, relating to macrophage. Rescue experiments showed that MACC1 overexpression can reverse the antitumor effect of curcumin in colorectal cancer cells and M2 polarization of TAMs. Curcumin's antiproliferative and anti-migratory effects in colorectal cancer cells may be mediated by MACC1 and inhibition of M2 polarization of TAMs.

Application of curcumin nanoformulations to target folic acid receptor in cancer: Recent trends and advances

Curcumin, derived from turmeric, has a strong anticancer potential known for millennia. The development of this phytochemical as a medicine has been hampered by several significant deficiencies, including its poor water solubility and low bioavailability. This review article discusses possibilities to overcome these bottlenecks by focusing on this natural polyphenol's nanoformulation. Moreover, preparation of curcumin conjugates containing folates as ligands for folic acid receptors can add a new important dimension in this field, allowing specific targeting of cancer cells, considering the significantly higher expression of these receptors in malignant tissues compared to normal cells. It is highly expected that simultaneous improvement of different aspects of curcumin in fighting against such a complex and multifaceted disease like cancer. Therefore, we can better comprehend cancer biology by developing a mechanistic understanding of curcumin, which will also inspire the scientific community to develop new pharmacological models, and exploration of emerging directions to revitalize application of natural products in cancer therapy.

Natural compounds targeting nuclear receptors for effective cancer therapy

Human nuclear receptors (NRs) are a family of forty-eight transcription factors that modulate gene expression both spatially and temporally. Numerous biochemical, physiological, and pathological processes including cell survival, proliferation, differentiation, metabolism, immune modulation, development, reproduction, and aging are extensively orchestrated by different NRs. The involvement of dysregulated NRs and NR-mediated signaling pathways in driving cancer cell hallmarks has been thoroughly investigated. Targeting NRs has been one of the major focuses of drug development strategies for cancer interventions. Interestingly, rapid progress in molecular biology and drug screening reveals that the naturally occurring compounds are promising modern oncology drugs which are free of potentially inevitable repercussions that are associated with synthetic compounds. Therefore, the purpose of this review is to draw our attention to the potential therapeutic effects of various classes of natural compounds that target NRs such as phytochemicals, dietary components, venom constituents, royal jelly-derived compounds, and microbial derivatives in the establishment of novel and safe medications for cancer treatment. This review also emphasizes molecular mechanisms and signaling pathways that are leveraged to promote the anti-cancer effects of these natural compounds. We have also critically reviewed and assessed the advantages and limitations of current preclinical and clinical studies on this subject for cancer prophylaxis. This might subsequently pave the way for new paradigms in the discovery of drugs that target specific cancer types.

Plants against cancer: the immune-boosting herbal microbiome: not of the plant, but in the plant. Basic concepts, introduction, and future resource for vaccine adjuvant discovery

The presence of microorganism communities (MOCs) comprised of bacteria, fungi, archaea, algae, protozoa, viruses, and the like, are ubiquitous in all living tissue, including plant and animal. MOCs play a significant role in establishing innate and acquired immunity, thereby influencing susceptibility and resistance to disease. This understanding has fostered substantial advancements in several fields such as agriculture, food science/safety, and the development of vaccines/adjuvants, which rely on administering inactivated-attenuated MOC pathogens. Historical evidence dating back to the 1800s, including reports by Drs Busch, Coley, and Fehleisen, suggested that acute febrile infection in response to "specific microbes" could trigger spontaneous tumor remission in humans. This discovery led to the purposeful administration of the same attenuated strains, known as "Coley's toxin," marking the onset of the first microbial (pathogen) associated molecular pattern (MAMPs or PAMPs)-based tumor immunotherapy, used clinically for over four decades. Today, these same MAMPS are consumed orally by billions of consumers around the globe, through "specific" mediums (immune boosting "herbal supplements") as carriers of highly concentrated MOCs accrued in roots, barks, hulls, sea algae, and seeds. The American Herbal Products Association (AHPA) mandates microbial reduction in botanical product processing but does not necessitate the removal of dead MAMP laden microbial debris, which we ingest. Moreover, while existing research has focused on the immune-modulating role of plant phytochemicals, the actual immune-boosting properties might instead reside solely in the plant's MOC MAMP laden biomass. This assertion is logical, considering that antigenic immune-provoking epitopes, not phytochemicals, are known to stimulate immune response. This review explores a neglected area of research regarding the immune-boosting effects of the herbal microbiome - a presence which is indirectly corroborated by various peripheral fields of study and poses a fundamental question: Given that food safety focuses on the elimination of harmful pathogens and crop science acknowledges the existence of plant microbiomes, what precisely are the immune effects of ingesting MAMPs of diverse structural composition and concentration, and where are these distributed in our botanicals? We will discuss the topic of concentrated edible MAMPs as acid and thermally stable motifs found in specific herbs and how these would activate cognate pattern recognition receptors (PPRs) in the upper gut-associated lymphoid tissue (GALT), including Peyer's patches and the lamina propria, to boost antibody titers, CD8+ and CD4+ T cells, NK activity, hematopoiesis, and facilitating M2 to M1 macrophage phenotype transition in a similar manner as vaccines. This new knowledge could pave the way for developing bioreactor-grown/heat-inactivated MOC therapies to boost human immunity against infections and improve tumor surveillance.

Targeting Signaling Pathway by Curcumin in Osteosarcoma

The most prevalent primary bone malignancy among children and adolescents is osteosarcoma. The high mortality rate of osteosarcoma is due to lung metastasis. Despite the development of multi-agent chemotherapy and surgical resection, patients with osteosarcoma have a high metastasis rate and poor prognosis. Thus, it is necessary to identify novel therapeutic agents to improve the 5-year survival rate of these patients. Curcumin, a phytochemical compound derived from Curcuma longa, has been employed in treating several types of cancers through various mechanisms. Also, in vitro studies have demonstrated that curcumin could inhibit cell proliferation and induce apoptosis in osteosarcoma cells. Development in identifying signaling pathways involved in the pathogenesis of osteosarcoma has provided insight into finding new therapeutic targets for the treatment of this cancer. Targeting MAPK/ERK, PI3k/AKT, Wnt/β-catenin, Notch, and MircoRNA by curcumin has been evaluated to improve outcomes in patients with osteosarcoma. Although curcumin is a potent anti-cancer compound, it has rarely been studied in clinical settings due to its congenital properties such as hydrophobicity and poor bioavailability. In this review, we recapitulate and describe the effect of curcumin in regulating signaling pathways involved in osteosarcoma.

Curcumin activates NLRC4, AIM2, and IFI16 inflammasomes and induces pyroptosis by up-regulated ISG3 transcript factor in acute myeloid leukemia cell lines

Curcumin, the primary bioactive component isolated from turmeric, has been found to possess a variety of biological functions, including anti-leukemia activity. However, the effect of curcumin in different leukemia cells vary. In this study, we demonstrated that curcumin induced the expression of AIM2, IFI16, and NLRC4 inflammasomes in leukemia cells U937 by increasing the expression levels of ISG3 transcription factor complex, which activated caspase 1, promoted cleavage of GSDMD, and induced pyroptosis. We also found that pyroptosis executor GSDMD was not expressed in two curcumin-insensitive cells HL60 and K562 cells. In addition, exogenous overexpression of GSDMD by lentiviral transduction in K562 cells increased the anti-cancer activity of curcumin, and inhibiting the expression of GSDMD by shRNA enhanced U937 cells to resist curcumin. The results showed that inducing pyroptosis is a novel mechanism underlying the anti-leukemia effects of curcumin.

Molecular modeling piloted analysis for semicarbazone derivative of curcumin as a potent Abl-kinase inhibitor targeting colon cancer

The human Abl kinases comprise a family of proteins that are known to be key stimulus drivers in the signaling pathways modulating cell growth, cell survival, cell adhesion, and apoptosis. Recent collative studies have indicated the role of activation of Abl and Abl-related genes in solid tumors; further terming the Abl kinases as molecular switches which promote proliferation, tumorigenesis, and metastasis. The up-regulated Abl-kinase expression in colorectal cancer (CRC) and the role of Abl tyrosine kinase activity in the Matrigel invasion of CRC cells have cemented its significance in CRC advancement. Therefore, the requisite of identifying small molecules which serve as Abl selective inhibitors and designing anti-Abl therapies, particularly for CRC tumors, has driven this study. Curcumin has been touted as an effective inhibitor of cancer cells; however, it is limited by its physicochemical inadequacies. Hence, we have studied the behavior of heterocyclic derivatives of curcumin via computational tools such as pharmacophore-based virtual screening, molecular docking, free-energy binding, and ADME profiling. The most actively docked molecule, 3,5-bis(4-hydroxy-3-methylstyryl)-1H-pyrazole-1-carboxamide, was comparatively evaluated against Curcumin via molecular dynamics simulation using Desmond, Schrödinger. The study exhibited the improved stability of the derivative as compared to Curcumin in the tested protein pocket and displayed the interaction bonds with the contacted key amino acids. To further establish the claim, the derivatives were synthesized via the mechanism of cyclization of Curcumin and screened in vitro using SRB assay against human CRC cell line, HCT 116. The active derivative indicated an IC₅₀ value of 5.85 µM, which was sevenfold lower as compared to Curcumin’s IC₅₀ of 35.40 µM. Hence, the results base the potential role of the curcumin derivative in modulating Abl-kinase activity and in turn may have potential therapeutic value as a lead for CRC therapy.

Multiple Myeloma Inhibitory Activity of Plant Natural Products

A literature search on plant natural products with antimyeloma activity until the end of 2020 resulted in 92 compounds with effects on at least one human myeloma cell line. Compounds were divided in different compound classes and both their structure-activity-relationships as well as eventual correlations with the pathways described for Multiple Myeloma were discussed. Each of the major compound classes in this review (alkaloids, phenolics, terpenes) revealed interesting candidates, such as dioncophyllines, a group of naphtylisoquinoline alkaloids, which showed pronounced and selective induction of apoptosis when substituted in position 7 of the isoquinoline moiety. Interestingly, out of the phenolic compound class, two of the most noteworthy constituents belong to the relatively small subclass of xanthones, rendering this group a good starting point for possible further drug development. The class of terpenoids also provides noteworthy constituents, such as the highly oxygenated diterpenoid oridonin, which exhibited antiproliferative effects equal to those of bortezomib on RPMI8226 cells. Moreover, triterpenoids containing a lactone ring and/or quinone-like substructures, e.g., bruceantin, whitaferin A, withanolide F, celastrol, and pristimerin, displayed remarkable activity, with the latter two compounds acting as inhibitors of both NF-κB and proteasome chymotrypsin-like activity.