Curcumin in human osteosarcoma: From analogs to carriers

Amicis Omnia Sunt Communia: NF-κB Inhibition as an Alternative to Overcome Osteosarcoma Heterogeneity

Tumor heterogeneity poses a significant challenge in osteosarcoma (OS) treatment. In this regard, the "omics" era has constantly expanded our understanding of biomarkers and altered signaling pathways (i.e., PI3K/AKT/mTOR, WNT/β-catenin, NOTCH, SHH/GLI, among others) involved in OS pathophysiology. Despite different players and complexities, many commonalities have been described, among which the nuclear factor kappa B (NF-κB) stands out. Its altered activation is pervasive in cancer, with pleiotropic action on many disease-relevant traits. Thus, in the scope of this article, we highlight the evidence of NF-κB dysregulation in OS and its integration with other cancer-related pathways while we summarize the repertoire of compounds that have been described to interfere with its action. In silico strategies were used to demonstrate that NF-κB is closely coordinated with other commonly dysregulated signaling pathways not only by functionally interacting with several of their members but also by actively participating in the regulation of their transcription. While existing inhibitors lack selectivity or act indirectly, the therapeutic potential of targeting NF-κB is indisputable, first for its multifunctionality on most cancer hallmarks, and secondly, because, as a common downstream effector of the many dysregulated pathways influencing OS aggressiveness, it turns complex regulatory networks into a simpler picture underneath molecular heterogeneity.

Morin inhibits osteosarcoma migration and invasion by suppressing urokinase plasminogen activator through a signal transducer and an activator of transcription 3

Osteosarcoma, the most common primary bone cancer that affects adolescents worldwide, has the early metastatic potential to be responsible for high mortality rates. Morin has a multipurpose role in numerous cancers, whereas little is known about its role in osteosarcoma migration and invasion. Therefore, we hypothesized that morin suppresses the invasive activities and the migratory potential of human osteosarcoma cells. Our results showed that morin reduced migration and invasion capabilities in human osteosarcoma U2OS and HOS cells. Moreover, morin inhibited the urokinase plasminogen activator (uPA) expression through a signal transducer and an activator of transcription-3 (STAT3) phosphorylation. After STAT3 overexpression, the decrease of the migratory potential and uPA expression caused by 100 μM of morin in U2OS cells was countered, indicating that STAT3 contributes to the antimetastatic property of morin in human osteosarcoma cells by reducing uPA. In conclusion, morin may be a potential candidate for the antimetastatic treatment of human osteosarcoma.

Curcumin Analog L48H37 Induces Apoptosis in Human Oral Cancer Cells by Activating Caspase Cascades and Downregulating the Inhibitor of Apoptosis Proteins through JNK/p38 Signaling

L48H37 is a synthetic curcumin analog that has anticancer potentials. Here, we further explored the anticancer effect of L48H37 on oral cancer cells and its mechanistic acts. Cell cycle distribution was assessed using flow cytometric analysis. Apoptosis was elucidated by staining with PI/Annexin V and activation of the caspase cascade. Cellular signaling was explored using apoptotic protein profiling, Western blotting, and specific inhibitors. Our findings showed that L48H37 significantly reduced the cell viability of SCC-9 and HSC-3 cells, resulting in sub-G1 phase accumulation and increased apoptotic cells. Apoptotic protein profiling revealed that L48H37 increased cleaved caspase-3, and downregulated cellular inhibitor of apoptosis protein 1 (cIAP1) and X-linked inhibitor of apoptosis protein (XIAP) in SCC-9 cells, and the downregulated cIAP1 and XIAP in both oral cancer cells were also demonstrated by Western blotting. Meanwhile, L48H37 triggered the activation of caspases and mitogen-activated protein kinases (MAPKs). The involvement of c-Jun N-terminal kinase (JNK) and p38 MAPK (p38) in the L48H37-triggered apoptotic cascade in oral cancer cells was also elucidated by specific inhibitors. Collectively, these findings indicate that L48H37 has potent anticancer activity against oral cancer cells, which may be attributed to JNK/p38-mediated caspase activation and the resulting apoptosis. This suggests a potential benefit for L48H37 for the treatment of oral cancer.

HO-3867, a curcumin analog, elicits cell apoptosis and p38-mediated caspase activation in hepatocellular carcinoma

HO-3867, a synthetic curcumin analog, has displayed various tumor-suppressive characteristics and improved bioabsorption over its parent compound. However, its influences on the development of hepatocellular carcinoma (HCC) are poorly defined. To address this, we tested the anticarcinogenic impact of HO-3867 and investigated the underlying mechanisms in fighting liver cancer. Our result demonstrated that HO-3867 reduced the viability of HCC cells, accompanied by promotion of cell cycle arrest at the sub-G1 stage and apoptotic responses. Furthermore, a distinctive profile of apoptosis associated proteins, encompassing elevated heme oxygenase-1 (HO-1) level and caspase activation, was detected in HO-3867-stimulated HCC cells. In addition, such HO-3867-mediated elevation in caspase activation was dampened by pharmacological suppression of p38 activities. Taken together, our findings unveiled that HO-3867 triggered cell cycle arrest and apoptotic events in liver cancer, involving a p38-mediated activation of caspase cascades. These data highlighted a usefulness of curcumin or its analogs on the management of hepatocarcinogenesis.

Cytotoxicity Enhancement in Osteosarcoma with Multifunctional I-131 Radiotherapeutic Nanoparticles: In Vitro Three-Dimensional Spheroid Model and Release Kinetics Modeling

This novel radiolabeled chitosan nanoparticle, facilitated with curcumin, increased doxorubicin cytotoxicity and radiosensitivity to MG-63 osteosarcoma cells in a three-dimensional model. Delivery of the anti-epidermal growth factor receptor (EGFR) targeted carboxymethyl chitosan nanoparticles, directly labeled with Na131I (ICED-N), achieved deep tumor penetration in a three-dimensional model. Of three kinetic models, the Higuchi model more closely matched the experimental curve and release profiles. The anti-EGFR targeting resulted in a 513-fold greater targeting efficacy to MG-63 (EGFR+) cells than the control fibroblast (EGFR-) cells. The curcumin-enhanced ICED-N (4 × 0.925 MBq) fractionated-dose regime achieved an 18.3-fold increase in cell cytotoxicity compared to the single-dose (1 × 3.70 MBq) doxorubicin-loaded nanoparticle, and a 13.6-fold increase in cell cytotoxicity compared to the single-dose Na131I nanoparticle. Moreover, the ICED-N fractionated dose increased cells in the G2/M phase 8.78-fold, indicating the cell cycle arrest in the G2/M phase is associated with DNA fragmentation, and the intracellular damage is unable to be repaired. Overall, the results indicate that the fractionated dose was more efficacious than a single dose, and curcumin substantially increased doxorubicin cytotoxicity and amplified osteosarcoma cell radiosensitivity to Na131I.

Engineered nanomaterials enhance drug delivery strategies for the treatment of osteosarcoma

Osteosarcoma (OS) is the most common malignant bone tumor in adolescents, and the clinical treatment of OS mainly includes surgery, radiotherapy, and chemotherapy. However, the side effects of chemotherapy drugs are an issue that clinicians cannot ignore. Nanomedicine and drug delivery technologies play an important role in modern medicine. The development of nanomedicine has ushered in a new turning point in tumor treatment. With the emergence and development of nanoparticles, nanoparticle energy surfaces can be designed with different targeting effects. Not only that, nanoparticles have unique advantages in drug delivery. Nanoparticle delivery drugs can not only reduce the toxic side effects of chemotherapy drugs, but due to the enhanced permeability retention (EPR) properties of tumor cells, nanoparticles can survive longer in the tumor microenvironment and continuously release carriers to tumor cells. Preclinical studies have confirmed that nanoparticles can effectively delay tumor growth and improve the survival rate of OS patients. In this manuscript, we present the role of nanoparticles with different functions in the treatment of OS and look forward to the future treatment of improved nanoparticles in OS.

Curcumin alleviates 1-methyl- 4-phenyl- 1,2,3,6-tetrahydropyridine- induced Parkinson's disease in mice via modulating gut microbiota and short-chain fatty acids

Background: The microbiota-gut-brain axis has been proposed as a potential therapeutic target of PD. The effects of curcumin against Parkinson's disease have been demonstrated; however, its neuroprotective mechanisms remain unknown. Our study investigated the potential mechanisms through which curcumin ameliorates Parkinson's disease via the microbiota-gut-brain axis. Methods: Mice were randomly divided into four groups: control, Curcumin, MPTP, and MPTP + Curcumin. Motor deficits and gastrointestinal dysfunction were assessed using behavioral test, intestinal motility test, and fecal parameter measurement. The loss of dopaminergic neurons and intestinal barrier function was measured using Western blot and immunofluorescence. Shotgun metagenomic sequencing and LC-MS were parallelly performed on mice feces to investigate alterations in microbiota and metabolites. Results: Curcumin alleviated motor deficits and the loss of dopaminergic neurons in MPTP-induced mice. Curcumin ameliorated gastrointestinal and intestinal barrier dysfunctions in MPTP-induced mice. Curcumin reduced gut microbial dysbiosis and modulated carbohydrate metabolism in MPTP-induced mice. Curcumin restored short-chain fatty acid (SCFA) profiles in MPTP-induced mice. Conclusion: Concurrently, these results indicate that curcumin inhibits Parkinson's disease by regulating the gut microbiota and short-chain fatty acids.

Curcumin-loaded Butea monosperma gum-based hydrogel: A new excipient for controlled drug delivery and anti-bacterial applications

The wide spectrum of applications provided by curcumin has attracted researchers worldwide to identify its molecular targets and employ it in various biomedical applications. The present research work focuses on the development of a Butea monosperma gum-based hydrogel encapsulated with curcumin and further employing it for two diverse applications, i.e., drug delivery and anti-bacterial application. A central composite design was utilized for the optimization of significant process variables to achieve maximum swelling. A maximum of 662 % swelling was attained at the initiator (0.06 g), monomer (3 ml), crosslinker (0.08 g), solvent (14 ml), and time (60 s). Furthermore, the characterization of the synthesized hydrogel was performed via FTIR, SEM, TGA, H1-NMR, and XRD analysis. Various important properties like swelling rate under different solutions, water retention capacity, re-swelling capability, porosity, and density measurement suggested that the prepared hydrogel exhibited a highly stable crosslinked network with high porosity (0.23) and density (62.5 g/cm³) values. The encapsulation efficiency of curcumin in the hydrogel was reported to be 93 % and 87.3 %, respectively, wherein BM-g-poly(AA) ~ Cur exhibited excellent sustained pH-responsive site release of curcumin at two different pH values, with the maximum amount of release taking place at pH 7.4 (792 ppm) and a minimum at pH 5 (550 ppm) due to the lesser ionization of the functional groups present in the hydrogel at a lower pH value. Additionally, the results from the pH shock studies indicated our material to be stable and efficient even with fluctuations in pH, resulting in the optimal amount of drug release at each pH range. Furthermore, anti-bacterial studies revealed that the synthesized BM-g-poly(AA) ~ Cur was effective against both gram-negative and gram-positive bacteria, with maximum values of zones of inhibition of 16 mm in diameter, thereby showing the best results in comparison to the already developed matrices to date. As a result, the newly discovered BM-g-poly(AA) ~ Cur properties reflect the hydrogel network's suitability for drug release and anti-bacterial applications.

EF-24, a Curcumin Analog, Inhibits Cancer Cell Invasion in Human Nasopharyngeal Carcinoma through Transcriptional Suppression of Matrix Metalloproteinase-9 Gene Expression

Cancer metastasis is a main cause of failure in treating subjects with nasopharyngeal carcinoma (NPC) and is frequently linked to high death rates. EF-24, an analog of curcumin, has exhibited many anti-cancer properties and enhanced bioavailability over curcumin. Nevertheless, the effects of EF-24 on the invasiveness of NPC are poorly understood. In this study, we demonstrated that EF-24 effectively inhibited TPA-induced motility and invasion responses of human NPC cells but elicited very limited cytotoxicity. In addition, the TPA-induced activity and expression of matrix metalloproteinase-9 (MMP-9), a crucial mediator of cancer dissemination, were found to be reduced in EF-24-treated cells. Our reporter assays revealed that such a reduction in MMP-9 expression by EF-24 was transcriptionally mediated by NF-κB via impeding its nuclear translocation. Further chromatin immunoprecipitation assays displayed that the EF-24 treatment decreased the TPA-induced interaction of NF-κB with the MMP-9 promoter in NPC cells. Moreover, EF-24 inhibited the activation of JNK in TPA-treated NPC cells, and the treatment of EF-24 together with a JNK inhibitor showed a synergistic effect on suppressing TPA-induced invasion responses and MMP-9 activities in NPC cells. Taken together, our data demonstrated that EF-24 restrained the invasiveness of NPC cells through the transcriptional suppression of MMP-9 gene expression, implicating the usefulness of curcumin or its analogs in controlling the spread of NPC.

Therapeutic Potential of Phenolic Compounds in Medicinal Plants-Natural Health Products for Human Health

Phenolic compounds and flavonoids are potential substitutes for bioactive agents in pharmaceutical and medicinal sections to promote human health and prevent and cure different diseases. The most common flavonoids found in nature are anthocyanins, flavones, flavanones, flavonols, flavanonols, isoflavones, and other sub-classes. The impacts of plant flavonoids and other phenolics on human health promoting and diseases curing and preventing are antioxidant effects, antibacterial impacts, cardioprotective effects, anticancer impacts, immune system promoting, anti-inflammatory effects, and skin protective effects from UV radiation. This work aims to provide an overview of phenolic compounds and flavonoids as potential and important sources of pharmaceutical and medical application according to recently published studies, as well as some interesting directions for future research. The keyword searches for flavonoids, phenolics, isoflavones, tannins, coumarins, lignans, quinones, xanthones, curcuminoids, stilbenes, cucurmin, phenylethanoids, and secoiridoids medicinal plant were performed by using Web of Science, Scopus, Google scholar, and PubMed. Phenolic acids contain a carboxylic acid group in addition to the basic phenolic structure and are mainly divided into hydroxybenzoic and hydroxycinnamic acids. Hydroxybenzoic acids are based on a C6-C1 skeleton and are often found bound to small organic acids, glycosyl moieties, or cell structural components. Common hydroxybenzoic acids include gallic, syringic, protocatechuic, p-hydroxybenzoic, vanillic, gentistic, and salicylic acids. Hydroxycinnamic acids are based on a C6-C3 skeleton and are also often bound to other molecules such as quinic acid and glucose. The main hydroxycinnamic acids are caffeic, p-coumaric, ferulic, and sinapic acids.

Characterization of Stable Pyrazole Derivatives of Curcumin with Improved Cytotoxicity on Osteosarcoma Cell Lines

Curcumin (CUR) is a natural molecule that is unstable due to the presence of a bis-ketone. To obtain more stable derivatives in biological fluids, the bis-ketone was replaced with pyrazole or O-substituted oximes. Their stability in solution was studied by UV-visible spectrophotometry. The effects on proliferation were studied by MTT assay and/or clonogenicity assay. Induction of apoptosis was evaluated by annexin V staining and Western blot analysis. The bioavailability was obtained from the analysis of the molecular chemical-physical characteristics. The replacement of the bis-ketone with a pyrazole ring or O-substituted oximes improved the stability of all the CUR-derivative molecules. These derivatives were more stable than CUR in solution and were generally cytotoxic on a panel of cancer cell lines tested, and they promoted caspase-dependent apoptosis. Derivative 1 was the most potent in the osteosarcoma (OS) lines. With respect to CUR, this derivative showed cytotoxicity at least three times higher in the MTT assay. In addition, in the clonogenic assay, 1 maintained the activity in conditions of long treatment presumably by virtue of its improved stability in biological fluids. Notably, 1 should have improved chemical-physical characteristics of bioavailability with respect to CUR, which should allow for reaching higher blood levels than those observed in the CUR trials. In conclusion, 1 should be considered in future clinical studies on the treatment of OS, either alone or in combination with other medications currently in use.