Natural Health Products (NHP's) and Natural Compounds as Therapeutic Agents for the Treatment of Cancer; Mechanisms of Anti-Cancer Activity of Natural Compounds and Overall Trends

CD44/PD-L1-mediated networks in drug resistance and immune evasion of breast cancer stem cells: Promising targets of natural compounds

Cancer stem cells (CSCs) significantly interfere with immunotherapy, leading to challenges such as low response rates and acquired resistance. PD-L1 expression is associated with the CSC population's overexpression of CD44. Mounting evidence suggests that the breast cancer stem cell (BCSC) marker CD44 and the immune checkpoint PD-L1 contribute to treatment failure through their networks. Natural compounds can overcome therapy resistance in breast cancer by targeting mechanisms underlying resistance in BCSCs. This review provides an updated insight into the CD44 and PD-L1 networks of BCSCs in mediating metastasis and immune evasion. The review critically examines existing literature, providing a comprehensive understanding of the topic and emphasizing the impact of natural flavones on the signaling pathways of BCSCs. Additionally, the review discusses the potential of natural compounds in targeting CD44 and PD-L1 in breast cancer (BC). Natural compounds consistently show potential in targeting regulatory mechanisms of BCSCs, inducing loss of stemness, and promoting differentiation. They offer a promising approach for developing alternative therapeutic strategies to manage breast cancer.

Formulation, development and evaluation of hyaluronic acid-conjugated liposomal nanoparticles loaded with regorafenib and curcumin and their in vitro evaluation on colorectal cancer cell lines

Colorectal cancer is one of the major causes of global cancer, with chemotherapy and radiation therapy being effective but limited due to low specificity. Regorafenib, a multikinase inhibitor, provides hope to patients with metastatic colorectal cancer and was approved by the FDA in 2012. However, due to resistance issues and adverse events, its efficacy is compromised, necessitating further refinement. Meanwhile, curcumin, a compound of turmeric, exhibits anticancer effects through antioxidant and anti-inflammatory actions, induction of the apoptosis, arrest of cell cycle, inhibition of angiogenesis, and modulation of signaling pathways. Unfortunately, its clinical utility is limited by its poor bioavailability, pointing towards innovative drug delivery strategies for enhanced efficacy in colorectal cancer treatment. Hyaluronic acid (HA)-decorated liposomes (LIPO) have been developed to target colorectal cells through an overexpressed CD44 receptor, increasing antitumor and antimetastasis efficacy. This study investigates the possibility of loading curcumin (CUR) or regorafenib (REGO) into a liposomal formulation for passive and HA-actively targeted treatment, evaluating its critical quality attributes (CQA) (size, zeta potential, polydispersity index) and cytotoxic activity in the HT29 colorectal cancer cell line. The average particle size of the plain liposomes and those decorated with HA was 144.00 ± 0.78 nm and 140.77 ± 1.64 nm, respectively. In contrast, curcumin-loaded plain liposomes and HA-decorated liposomes had 140 ± 2.46 nm and 164.53 ± 15.13 nm, respectively. The prepared liposomes had a spherical shape with a narrow size distribution and an acceptable zeta potential of less than -30 mV. The encapsulation efficiency was 99.2 % ± 0.3 and 99.9 ± 0.2 % for HA-decorated and bare regorafenib loaded. The % EE was 98.9 ± 0.2 % and 97.5 ± 0.2 % for bare liposomal nanoparticles loaded with curcumin and coated with curcumin. The IC50 of free REGO, CUR, REGO-LIPO, CUR-LIPO, REGO-LIPO-HA and CUR-LIPO-HA were 20.17 ± 0.78, 64.4 ± 0.33, 224.8 ± 0.06, 49.66 ± 0.22, 73.66 ± 0.6, and 27.86 ± 0.49 µM, respectively. The MTT assay in HT29 cells showed significant cytotoxic activity of the HA-decorated liposomal formulation compared to the base uncoated formulation, indicating that hyaluronic acid-targeted liposomes loaded with regorafenib or curcumin could be a promising targeted formulation against colorectal cancer cells.

Does Boric Acid Inhibit Cell Proliferation on MCF-7 and MDA-MB-231 Cells in Monolayer and Spheroid Cultures by Using Apoptosis Pathways?

Most breast cancers originate in the lobules or ducts of the breast. Breast cancer as the second main cause of death among women in the world is the most common kind of cancer in women. Studies have been conducted to find the optimal treatment for breast cancer. Moreover, the therapeutic effects of different drugs and substances on this disease have been intensively researched. Boric acid accounts for 96% of the boron content in body fluids, and its derivatives are absorbed by the human body. It is assumed to be represented as (B(OH)2). Experimental studies have shown a reduction of cell proliferation and stimulation of apoptosis in some melanoma, prostate, and colon cancer cell lines through boric acid. The aim of this study was to investigate if boric acid could be used for treating breast cancer. The impacts of boric acid on the human breast carcinoma cell lines MCF-7 and MDA-MB-231 were studied with TUNEL, BrdU, caspase-3, and endo-G immunohistochemical studies in 3D and 2D culture systems. Furthermore, we conducted a qRT-PCR study to show changes in the expression of some genes involved in apoptosis. Suppression of cell proliferation through boric acid-inducing apoptosis was observed both in 3D and 2D culture conditions. These results are compatible with the gene expression results. The ENDOG, CASP3, CASP8, and CASP9 gene expression significantly changed at all time intervals in MCF-7 and MD-MB-231 cell lines boric acid can potentially treat breast cancer as an anti-cancer agent candidate.

Phytometabolites as modulators of breast cancer: a comprehensive review of mechanistic insights

Breast cancer (BC) is a highly debilitating malignancy affecting females globally and imposing a substantial burden on healthcare systems in both developed and developing nations. Despite the application of conventional therapeutic modalities such as chemotherapy, radiation therapy, and hormonal intervention, BC frequently exhibits resistance, necessitating the urgent development of novel, cost-effective, and accessible treatment strategies. In this context, there is a growing scientific interest in exploring the pharmacological potential of chemical compounds derived from botanical sources, which often exhibit notable biological activity. Extensive in vitro and in vivo investigations have revealed the capacity of these compounds, referred to as phytochemicals, to attenuate the metastatic cascade and reduce the risk of cancer dissemination. These phytochemicals exert their effects through modulation of key molecular and metabolic processes, including regulation of the cell cycle, induction of apoptotic cell death, inhibition of angiogenesis, and suppression of metastatic progression. To shed light on the latest advancements in this field, a comprehensive review of the scientific literature has been conducted, focusing on secondary metabolite agents that have recently been investigated and have demonstrated promising anticancer properties. This review aims to delineate their underlying mechanisms of action and elucidate the associated signaling pathways, thereby contributing to a deeper understanding of their therapeutic potential in the context of BC management.

Cancer patients' behaviors and attitudes toward natural health products

BACKGROUND

Natural health products (NHPs), including vitamins, minerals, and herbal supplements, are the most common complementary and alternative medicine (CAM) among cancer patients. Our survey determined the attitudes and behaviors of cancer patients toward natural complementary therapies that should be considered to implement an integrative approach in the future.

METHODS

Our survey was conducted in four hospitals in Belgium. Questionnaires were posted online from October 2020 to October 2021 for cancer patients. Descriptive statistics were used to analyze the data. A [Formula: see text] test was applied to study the type of NHP consumed according to diagnosis time. Fischer's exact test compared patients who had changed their consumption since diagnosis and those who had not.

RESULTS

Out of 349 questionnaires collected, only 59 met all inclusion criteria. 83.1 % of the patients agreed that conventional medicine (CM) could benefit from complementary therapies, but they did not estimate (72.3 % of the patients) that those latter are more effective than conventional medicine. More than half of the patients used five or more NHPs. The most frequent NHPs consumed daily were vitamins (64.4 %), followed by other products (i.e., probiotics, gemmotherapy, birch sap and omega 3/6) (42.4 %) and herbs (40.7 %). Almost all patients started taking NHPs before their cancer diagnosis, but 72.7 % have changed their consumption significantly (p = 0.009) since their diagnosis. Boosting the immune system (79.7 %) and limiting conventional treatment side effects (76.9 %) were the most common reasons for NHPs' use. 74.4 % of the patients did not take complementary therapies to delay or avoid conventional treatment.

CONCLUSIONS

The combination and high diversity of NHPs consumption highlight the importance of educating patients and healthcare providers (HCPs) about the risk of drug interactions associated with these natural products. Most cancer patients are more interested in using this non-mainstream medicine to complement their conventional treatment than as an alternative. Knowing the patients' reasons and understanding patients' attitudes toward NHPs will be essential for HCPs to address NHPs' use.

Anti-cancer activity of Marsdenialongise A, a new C21 steroidal glycoside isolated from Marsdenia longipes W.T. Wang (Apocynaceae)

C21 steroidal glycosides are a group of natural compounds with biological activities such as anti-cancer, anti-microbial, and anti-viral properties. In this study, we isolated and determined the structure of a new C21 steroidal glycoside, named Marsdenialongise A from Marsdenia longipes W.T. Wang, using nuclear magnetic resonance spectroscopy and mass spectra data. Marsdenialongise A is a derivative of tenacigenin B and was isolated for the first time from a plant. The inhibitory effect of Marsdenialongise A on cancer cells was evaluated through MTT and cell migration assays, cell cycle, and apoptosis analyses. The results of the MTT assay showed that Marsdenialongise A reduces the cell viability of cancer cells, with the AGS cell line being more sensitive than other cell lines, with an IC50 value of 5.69 µM (for 48 h of treatment). Marsdenialongise A also exhibited an ability to prevent the migration of cancer cells in AGS cells. Further analysis using flow cytometry has revealed that Marsdenialongise A is capable of inducing cell cycle arrest and apoptosis. The overexpression of reactive oxygen species (ROS) production induced by Marsdenialongise A can be considered a cause that leads to the influence on the cell cycle and apoptosis of cancer cells. Thus, Marsdenialongise A can be considered a potential anti-cancer agent.

Licochalcone D Inhibits Skin Epidermal Cells Transformation through the Regulation of AKT Signaling Pathways

Cell transformation induced by epidermal growth factor (EGF) and 12-O-tetradecanoylphorbol-13-acetate (TPA) is a critical event in cancer initiation and progression, and understanding the underlying mechanisms is essential for the development of new therapeutic strategies. Licorice extract contains various bioactive compounds, which have been reported to have anticancer and anti-inflammatory effects. This study investigated the cancer preventive efficacy of licochalcone D (LicoD), a chalcone derivative in licorice extract, in EGF and TPA-induced transformed skin keratinocyte cells. LicoD effectively suppressed EGF-induced cell proliferation and anchorage-independent colony growth. EGF and TPA promoted the S phase of cell cycle, while LicoD treatment caused G1 phase arrest and down-regulated cyclin D1 and up-regulated p21 expression associated with the G1 phase. LicoD also induced apoptosis and increased apoptosis-related proteins such as cleaved-caspase-3, cleaved-caspase-7, and Bax (Bcl-2-associated X protein). We further investigated the effect of LicoD on the AKT signaling pathway involved in various cellular processes and found decreased p-AKT, p-GSK3β, and p-NFκB expression. Treatment with MK-2206, an AKT pharmacological inhibitor, suppressed EGF-induced cell proliferation and transformed colony growth. In conclusion, this study demonstrated the potential of LicoD as a preventive agent for skin carcinogenesis.

Antiproliferative activity and apoptosis-inducing mechanism of Curcuma longa (Turmimax®) on HeLa cell lines

Curcumin, the primary polyphenol found in turmeric, is derived from the Curcuma longa plant. Since curcumin is nontoxic and has a wide range of medicinal qualities, including anti-oxidant, analgesic, anti-inflammatory, and antibacterial action, it has been widely employed in Ayurveda medicine for ages. Curcumin has recently been discovered to have anti-cancer properties through its impact on numerous biological pathways involved in carcinogenesis, metastasis, tumorigenesis, cell cycle regulation, mutagenesis, and oncogene expression. In this study, we determined the Antiproliferative activity and apoptosis-inducing mechanism of C. longa (Turmimax®) on human cancer cells. The cytotoxic effect was evaluated against HeLa cell lines using the MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. Flow cytometric analysis was performed to detect apoptotic cell death. Turmimax® exhibits promising properties as a potential anti-cancer therapeutic agent in human cervical adenocarcinomas and possibly other cancer types, with an IC50 value of 87.89 µg/mL. In HeLa cells treated with Turmimax®, cell cycle arrest was seen in the G0/G1 and S phases. By inducing apoptosis and increasing the number of apoptotic cells in a dose-dependent manner, the experimental data suggest that Turmimax® has considerable promise in cancer prevention and treatment.

Tiliroside Combined with Anti-MUC1 Monoclonal Antibody as Promising Anti-Cancer Strategy in AGS Cancer Cells

Specific changes in mucin-type O-glycosylation are common for many cancers, including gastric ones. The most typical alterations include incomplete synthesis of glycan structures, enhanced expression of truncated O-glycans (Tn, T antigens and their sialylated forms), and overexpression of fucosylation. Such altered glycans influence many cellular activities promoting cancer development. Tiliroside is a glycosidic dietary flavonoid with pharmacological properties, including anti-cancer. In this study, we aim to assess the effect of the combined action of anti-MUC1 and tiliroside on some cancer-related factors in AGS gastric cancer cells. Cancer cells were treated with 40, 80, and 160 µM tiliroside, 5 µg/mL anti-MUC1, and flavonoid together with mAb. Real-Time PCR, ELISA, and Western blotting were applied to examine MUC1 expression, specific, tumor-associated antigens, enzymes taking part in their formation, Gal-3, Akt, and NF-κB. MUC1 expression was significantly reduced by mAb action. The combined action of anti-MUC1 and tiliroside was more effective in comparison with monotherapy in the case of C1GalT1, ST3GalT1, FUT4, Gal-3, NF-κB, Akt mRNAs, and Tn antigen, as well as sialyl T antigen expression. The results of our study indicate that applied combined therapy may be a promising anti-gastric cancer strategy.

Ethanolic extract of Origanum syriacum L. leaves exhibits potent anti-breast cancer potential and robust antioxidant properties

Background: Breast cancer (BC) is the second most common cancer overall. In women, BC is the most prevalent cancer and the leading cause of cancer-related mortality. Triple-negative BC (TNBC) is the most aggressive BC, being resistant to hormonal and targeted therapies. Hypothesis/Purpose: The medicinal plant Origanum syriacum L. is a shrubby plant rich in bioactive compounds and widely used in traditional medicine to treat various diseases. However, its therapeutic potential against BC remains poorly investigated. In the present study, we screened the phytochemical content of an ethanolic extract of O. syriacum (OSEE) and investigated its anticancer effects and possible underlying mechanisms of action against the aggressive and highly metastatic human TNBC cell line MDA-MB-231. Methods: MTT, trans-well migration, and scratch assays were used to assess cell viability, invasion, or migration, respectively. Antioxidant potential was evaluated in vitro using the DPPH radical-scavenging assay and levels of reactive oxygen species (ROS) were assessed in cells in culture using DHE staining. Aggregation assays were used to determine cell-cell adhesion. Flow cytometry was used to analyze cell cycle progression. Protein levels of markers of apoptosis (BCL-2, pro-Caspase3, p53), proliferation (p21, Ki67), cell migration, invasion, or adhesion (FAK, E-cadherin), angiogenesis (iNOS), and cell signaling (STAT3, p38) were determined by immunoblotting. A chorioallantoic Membrane (CAM) assay evaluated in ovo angiogenesis. Results: We demonstrated that OSEE had potent radical scavenging activity in vitro and induced the generation of ROS in MDA-MB-231 cells, especially at higher OSEE concentrations. Non-cytotoxic concentrations of OSEE attenuated cell proliferation and induced G₀/G₁ cell cycle arrest, which was associated with phosphorylation of p38 MAPK, an increase in the levels of tumor suppressor protein p21, and a decrease of proliferation marker protein Ki67. Additionally, only higher concentrations of OSEE were able to attenuate inhibition of proliferation induced by the ROS scavenger N-acetyl cysteine (NAC), indicating that the anti-proliferative effects of OSEE could be ROS-dependent. OSEE stimulated apoptosis and its effector Caspase-3 in MDA-MB-231 cells, in correlation with activation of the STAT3/p53 pathway. Furthermore, the extract reduced the migration and invasive properties of MDA-MB-231 cells through the deactivation of focal adhesion kinase (FAK). OSEE also reduced the production of inducible nitric oxide synthase (iNOS) and inhibited in ovo angiogenesis. Conclusion: Our findings reveal that OSEE is a rich source of phytochemicals and has robust anti-breast cancer properties that significantly attenuate the malignant phenotype of MD-MB-231 cells, suggesting that O. syriacum may not only act as a rich source of potential TNBC therapeutics but may also provide new avenues for the design of novel TNBC drugs.

Biosynthesis of silver nanoparticles using Citrus hystrix leaf extract and evaluation of its anticancer efficacy against HeLa cell line

BACKGROUND

Cervical cancer continues to be the leading cause of death worldwide despite the availability of many therapeutic options. Biogenic synthesis of metal nanoparticles paves a new way for the development of targeted drug delivery modalities of cancer therapeutics.

OBJECTIVE

In this study, we demonstrate the efficacy of biosynthesized silver nanoparticles from methanolic leaf extract of Citrus hystrix as an anticancer agent used against cervical cancer cell line HeLa.

METHODS

The addition of 1mM silver nitrate to methanolic leaf extract of Citrus hystrix resulted in the biosynthesis of silver nanoparticles during the reaction mixture and was incubated in the dark for 1 hour at pH 9 with gentle stirring. Characterization of synthesized NPs was carried out using various analyses. MTT assay, DAPI, AO/EB double staining and RT-PCR analysis were carried out to evaluate the cytotoxic activity of ChAgNPs.

RESULTS AND CONCLUSION

The absorption band at 430 nm, as shown by UV-Vis spectroscopy revealed the formation of AgNPs. SEM and TEM analysis shows that most of the ChAgNPs were spherical in shape and XRD patterns revealed the crystalline nature of the particles. Moreover, its potent cytotoxic effect on the HeLa cell line was analyzed using MTT assay with an IC₅₀ value of 56 µg/ml by decreasing the cell viability in a dose and time-dependent manner. The induced apoptotic activity was confirmed by DAPI and double staining methods. Autophagic and apoptotic mediated cell death in ChAgNPs treated HeLa cell line were confirmed by staining procedures and RT-PCR methods.

New Achievements for the Treatment of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) constitutes a heterogeneous group of malignancies that are often aggressive and associated with a poor prognosis. The development of new TNBC treatment strategies has become an urgent clinical need. Diagnosis and subtyping of TNBC are essential to establish alternative treatments and targeted therapies for every TNBC patient. Chemotherapy, particularly with anthracycline and taxanes, remains the backbone for medical management for both early and metastatic TNBC. More recently, immune checkpoint inhibitors and targeted therapy have revolutionized cancer treatment. Included in the different strategies studied for TNBC treatment is drug repurposing. Despite the numerous medications available, numerous studies in medicinal chemistry are still aimed at the synthesis of new compounds in order to find new antiproliferative agents capable of treating TNBC. Additionally, some supplemental micronutrients, nutraceuticals and functional foods can potentially reduce the risk of developing cancer or can retard the rate of growth and metastases of established malignant diseases. Finally, nanotechnology in medicine, termed nanomedicines, introduces nanoparticles of variable chemistry and architecture for cancer treatment. This review highlights the most recent studies in search of new therapies for the treatment of TNBC, along with nutraceuticals and repositioning of drugs.

Natural Products in Preventing Tumor Drug Resistance and Related Signaling Pathways

Drug resistance is still an obstacle in cancer therapy, leading to the failure of tumor treatment. The emergence of tumor drug resistance has always been a main concern of oncologists. Therefore, overcoming tumor drug resistance and looking for new strategies for tumor treatment is a major focus in the field of tumor research. Natural products serve as effective substances against drug resistance because of their diverse chemical structures and pharmacological effects. We reviewed the signaling pathways involved in the development of tumor drug resistance, including Epidermal growth factor receptor (EGFR), Renin-angiotensin system (Ras), Phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt), Wnt, Notch, Transforming growth factor-beta (TGF-β), and their specific signaling pathway inhibitors derived from natural products. This can provide new ideas for the prevention of drug resistance in cancer therapy.

Boric acid suppresses cell proliferation by TNF signaling pathway mediated apoptosis in SW-480 human colon cancer line

BACKGROUND/AIM

Colon cancer is one of the most common cancers. Treatment success and survival rates are not high enough with current approaches. Therefore, there is a need to develop new agents and treatment methods. Boric acid is the most frequently observed form of boron. Some epidemiological data suggest that environmental exposure to boric acid reduces the incidence of prostate cancer in men, cervical and lung cancers in women. Experimental studies show, boric acid reduces cell proliferation and stimulates apoptosis in some prostate, melanoma, breast cancer cell lines. In this study, it was investigated whether boric acid could be a new candidate molecule that could be used in the treatment of colon cancer.

MATERIALS AND METHODS

The effects of boric acid on human colon adenocarcinoma cell line SW-480 were investigated with BrdU, TUNEL, Caspase-3, and AIF immunohistochemical studies in both 2D and 3D culture systems. In addition, a qRT-PCR study was carried out to determine the expression changes in key genes that take part in apoptosis.

RESULTS

We observed that boric acid suppresses cell proliferation and induces apoptosis both in 2D and 3D culture conditions. In addition, as a result of qRt-PCR studies, it was revealed that the observed apoptotic process was related to the TNF signaling pathway.

CONCLUSION

Boric acid can be considered as a potential anti-cancer agent candidate for colon cancer treatment.

DATA AVAILABILITY

All data generated or analyzed during this study are included in this published article.

The Cooperative Anti-Neoplastic Activity of Polyphenolic Phytochemicals on Human T-Cell Acute Lymphoblastic Leukemia Cell Line MOLT-4 In Vitro

Acute lymphoblastic leukemia (ALL) is the most common hematological malignancy affecting pediatric patients. ALL treatment regimens with cytostatics manifest substantial toxicity and have reached the maximum of well-tolerated doses. One potential approach for improving treatment efficiency could be supplementation of the current regimen with naturally occurring phytochemicals with anti-cancer properties. Nutraceuticals such as quercetin, curcumin, resveratrol, and genistein have been studied in anti-cancer therapy, but their application is limited by their low bioavailability. However, their cooperative activity could potentially increase their efficiency at low, bioavailable doses. We studied their cooperative effect on the viability of a human ALL MOLT-4 cell line in vitro at the concentration considered to be in the bioavailable range in vivo. To analyze their potential side effect on the viability of non-tumor cells, we evaluated their toxicity on a normal human foreskin fibroblast cell line (BJ). In both cell lines, we also measured specific indicators of cell death, changes in cell membrane permeability (CMP), and mitochondrial membrane potential (MMP). Even at a low bioavailable concentration, genistein and curcumin decreased MOLT-4 viability, and their combination had a significant interactive effect. While resveratrol and quercetin did not affect MOLT-4 viability, together they enhanced the effect of the genistein/curcumin mix, significantly inhibiting MOLT-4 population growth in vitro. Moreover, the analyzed phytochemicals and their combinations did not affect the BJ cell line. In both cell lines, they induced a decrease in MMP and correlating CMP changes, but in non-tumor cells, both metabolic activity and cell membrane continuity were restored in time. (4) Conclusions: The results indicate that the interactive activity of analyzed phytochemicals can induce an anti-cancer effect on ALL cells without a significant effect on non-tumor cells. It implies that the application of the combinations of phytochemicals an anti-cancer treatment supplement could be worth further investigation regardless of their low bioavailability.

The Employment of Genera Vaccinium, Citrus, Olea, and Cynara Polyphenols for the Reduction of Selected Anti-Cancer Drug Side Effects

Cancer is one of the most widespread diseases globally and one of the leading causes of death. Known cancer treatments are chemotherapy, surgery, radiation therapy, targeted hormonal therapy, or a combination of these methods. Antitumor drugs, with different mechanisms, interfere with cancer growth by destroying cancer cells. However, anticancer drugs are dangerous, as they significantly affect both cancer cells and healthy cells. In addition, there may be the onset of systemic side effects perceived and mutagenicity, teratogenicity, and further carcinogenicity. Many polyphenolic extracts, taken on top of common anti-tumor drugs, can participate in the anti-proliferative effect of drugs and significantly reduce the side effects developed. This review aims to discuss the current scientific knowledge of the protective effects of polyphenols of the genera Vaccinium, Citrus, Olea, and Cynara on the side effects induced by four known chemotherapy, Cisplatin, Doxorubicin, Tamoxifen, and Paclitaxel. In particular, the summarized data will help to understand whether polyphenols can be used as adjuvants in cancer therapy, although further clinical trials will provide crucial information.

Two Zn(II) coordination polymers with anticancer drug norcantharidin as ligands for cancer chemotherapy

Here two Zn(II) coordination polymers [Zn₂₀(DMCA)₁₂]O₁₂ (DMCA = demethylcantharic acid, DMCA-Zn1) and [Zn(DMCA)](H₂O)₂ (DMCA-Zn2) are synthesized from a broad-spectrum anticancer drug norcantharidin (NCTD) and Zn(NO₃)₂·6H₂O under solvothermal conditions. By mechanical grinding with a biocompatible polymeric surfactant F127, ultrasonic treatment and filtration, DMCA-Zn1 and DMCA-Zn2 can be transformed into stable nanoparticles (DMCA-Zn1 NPs and DMCA-Zn2 NPs) suspended in water with average diameters of around 190 nm and 162 nm for drug delivery. The in vitro evaluation indicates that DMCA-Zn1 NPs and DMCA-Zn2 NPs can enter into HepG2 and Hep3B cancer cells via endocytosis and inhibit their proliferation. Meanwhile they exhibit relatively low toxicity to L927 normal cells. The in vivo evaluation confirms that DMCA-Zn1 NPs and DMCA-Zn2 NPs can more effectively inhibit the growth of Hep3B tumors with relatively few side effects compared with free NCTD. This approach can be extended to other anticancer drugs to construct nanodrug delivery systems for cancer treatment.

Nutraceuticals and Cancer: Potential for Natural Polyphenols

Cancer is one of the leading causes of death globally, associated with multifactorial pathophysiological components. In particular, genetic mutations, infection or inflammation, unhealthy eating habits, exposition to radiation, work stress, and/or intake of toxins have been found to contribute to the development and progression of cancer disease states. Early detection of cancer and proper treatment have been found to enhance the chances of survival and healing, but the side effects of anticancer drugs still produce detrimental responses that counteract the benefits of treatment in terms of hospitalization and survival. Recently, several natural bioactive compounds were found to possess anticancer properties, capable of killing transformed or cancerous cells without being toxic to their normal counterparts. This effect occurs when natural products are associated with conventional treatments, thereby suggesting that nutraceutical supplementation may contribute to successful anticancer therapy. This review aims to discuss the current literature on four natural bioactive extracts mostly characterized by a specific polyphenolic profile. In particular, several activities have been reported to contribute to nutraceutical support in anticancer treatment: (1) inhibition of cell proliferation, (2) antioxidant activity, and (3) anti-inflammatory activity. On the other hand, owing to their attenuation of the toxic effect of current anticancer therapies, natural antioxidants may contribute to improving the compliance of patients undergoing anticancer treatment. Thus, nutraceutical supplementation, along with current anticancer drug treatment, may be considered for better responses and compliance in patients with cancer. It should be noted, however, that when data from studies with bioactive plant preparations are discussed, it is appropriate to ensure that experiments have been conducted in accordance with accepted pharmacological research practices so as not to disclose information that is only partially correct.

Synergistic Effect Induced by Gold Nanoparticles with Polyphenols Shell during Thermal Therapy: Macrophage Inflammatory Response and Cancer Cell Death Assessment

BACKGROUND

In recent decades, gold nanoparticle (Au NP)-based cancer therapy has been heavily debated. The physico-chemical properties of AuNPs can be exploited in photothermal therapy, making them a powerful tool for selectively killing cancer cells. However, the synthetic side products and capping agents often induce a strong activation of the inflammatory pathways of macrophages, thus limiting their further applications in vivo.

METHODS

Here, we described a green method to obtain stable polyphenol-capped AuNPs (Au NPs@polyphenols), as polyphenols are known for their anti-inflammatory and anticancer properties. These NPs were used in human macrophages to test key inflammation-related markers, such as NF-κB, TNF-α, and interleukins-6 and 8. The results were compared with similar NPs obtained by a traditional chemical route (without the polyphenol coating), proving the potential of Au NPs@polyphenols to strongly promote the shutdown of inflammation. This was useful in developing them for use as heat-synergized tools in the thermal treatment of two types of cancer cells, namely, breast cancer (MCF-7) and neuroblastoma (SH-SY5Y) cells. The cell viability, calcium release, oxidative stress, HSP-70 expression, mitochondrial, and DNA damage, as well as cytoskeleton alteration, were evaluated.

RESULTS

Our results clearly demonstrate that the combined strategy markedly exerts anticancer effects against the tested cancer cell, while neither of the single treatments (only heat or only NPs) induced significant changes.

CONCLUSIONS

Au NP@polyphenols may be powerful agents in cancer treatment.

Anticancer Activity of Two Novel Hydroxylated Biphenyl Compounds toward Malignant Melanoma Cells

Melanoma, the deadliest form of skin cancer, is still one of the most difficult cancers to treat despite recent advances in targeted and immune therapies. About 50% of advanced melanoma do not benefit of such therapies, and novel treatments are requested. Curcumin and its analogs have shown good anticancer properties and are being considered for use in combination with or sequence to recent therapies to improve patient outcomes. Our group previously published the synthesis and anticancer activity characterization of a novel curcumin-related compound against melanoma and neuroblastoma cells (D6). Here, two hydroxylated biphenyl compounds-namely, compounds 11 and 12-were selected among a small collection of previously screened C2-symmetric hydroxylated biphenyls structurally related to D6 and curcumin, showing the best antitumor potentiality against melanoma cells (IC50 values of 1.7 ± 0.5 μM for 11 and 2.0 ± 0.7 μM for 12) and no toxicity of normal fibroblasts up to 32 µM. Their antiproliferative activity was deeply characterized on five melanoma cell lines by performing dose-response and clonal growth inhibition assays, which revealed long-lasting and irreversible effects for both compounds. Apoptosis induction was ascertained by the annexin V and TUNEL assays, whereas Western blotting showed caspase activation and PARP cleavage. A cell cycle analysis, following cell treatments with either compound 11 or 12, highlighted an arrest in the G2/M transition. Taking all this evidence together, 11 and 12 were shown to be good candidates as lead compounds to develop new anticancer drugs against malignant melanoma.

Effectiveness of Complementary Therapies in Cancer Patients: A Systematic Review

According to the World Health Organization, cancer is the second leading cause of death in the world. In Spain, about a quarter of a million cases were diagnosed in 2017, and 81% of the Spanish population has used, at least once, some kind of complementary therapy. Said therapies are increasingly being used by cancer patients. The purpose of the study is to analyse the effectiveness of complementary therapies among cancer patients. A systematic peer review was conducted following the PRISMA-ScR guide in four databases (PubMed, CINAHL, Scopus and WOS). The inclusion criteria were Randomised Clinical Trials, published between 2013 and 2018, with a value of 3 or more on the Jadad Scale. The protocol was registered in PROSPERO (CRD42019127593). The study sample amounted to 1845 patients (64.55% women), the most common being breast cancer patients (794), followed by lung cancer patients (341). Fifteen complementary therapies were identified. We found two studies for each of the following: electroacupuncture, phytotherapy, hypnotherapy, guided imagery and progressive muscle relaxation. From the remaining ones, we identified a study on each therapy. The findings reveal some effective complementary therapies: auriculotherapy and acupuncture, laser moxibustion, hypnosis, Ayurveda, electroacupuncture, progressive muscle relaxation and guided imagery, yoga, phytotherapy, music therapy and traditional Chinese medicine. On the other hand, electroacupuncture, laser moxibustion and traditional Chinese medicine presented adverse effects, and kinesiology did not show effectiveness.