Perspectives on natural compounds in chemoprevention and treatment of cancer: an update with new promising compounds

Rice bran arabinoxylan compound as a natural product for cancer treatment - an evidence-based assessment of the effects and mechanisms

CONTEXT

Rice bran arabinoxylan compound (RBAC) is a natural immunomodulator with anticancer properties.

OBJECTIVE

This study critically evaluates the available evidence on the biological pathways of RBAC and its effects on cancer treatment.

METHODS

This secondary analysis of a scoping review includes studies evaluating the mechanisms of RBAC on healthy or malignant cells, animal models, or humans for cancer prevention or treatment. Data from randomized controlled trials on survival and quality of life outcomes were subjectd to meta analysis.

RESULTS

The evidence synthesis was based on 38 articles. RBAC exhibited antitumor properties by promoting apoptosis and restoring immune function in cancer patients to enhance inflammatory and cytotoxic responses to block tumorigenesis. RBAC works synergistically with chemotherapeutic agents by upregulating drug transport. In a clinical trial, combining RBAC with chemoembolization in treating liver cancer showed improved response, reduced recurrence rates, and prolonged survival. RBAC also augments the endogenous antioxidant system to prevent oxidative stress and protect against radiation side effects. In addition, RBAC has chemoprotective effects. Animals and humans have exhibited reduced toxicity and side effects from chemotherapy. Meta analysis indicates that RBAC treatment increases the survival odds by 4.02-times (95% CI: 1.67, 9.69) in the first year and 2.89-times (95% CI: 1.56, 5.35) in the second year.

CONCLUSION

RBAC is a natural product with immense potential in cancer treatment. Additional research is needed to characterize, quantify, and standardize the active ingredients in RBAC responsible for the anticancer effects. More well-designed, large-scale clinical trials are required to substantiate the treatment efficacies further.

The Inhibition Mechanisms of Three Structurally Different Salvianolic Acids on the Non-Enzymatic Glycation of Bovine Serum Albumin

The antiglycation mechanisms of three structurally different salvianolic acids (Sals) including salvianolic acid A (Sal-A), salvianolic acid B (Sal-B) and salvianolic acid C (Sal-C) were investigated using the bovine serum albumin (BSA)-fructose model. The results showed that the three compounds could inhibit the formation of glycation products, maintain protein structural stability, mitigate the development of amyloid fibrils and scavenge radicals. Notably, Sal-A possessed the highest anti-glycated activity compared with Sal-B and Sal-C. This may be related to the fact that Sal-A contained the most molecules of caffeic acid (Sal-A, Sal-B, and Sal-C possessing two, one, and zero caffeic acid units, respectively), and caffeic acid played a leading role in the antiglycation properties relative to Danshensu. Moreover, these compounds quenched the intrinsic fluorescence intensity of BSA in a static mode, with the binding constants in the order of Sal-A > Sal-B > Sal-C. Obviously, Sal-A possessed the strongest binding affinity among these compounds, which may be one of the reasons why it exhibited the optimal antiglycation capability. Furthermore, molecular docking demonstrated that the three Sals exerted protective effects on BSA by preventing glycation modification of lysine and arginine residues. These findings would provide valuable insights into the potential application of Sals for alleviating non-enzymatic glycation of protein.

Contribution of non-steroidal anti-inflammatory drugs to breast cancer treatment: In vitro and in vivo studies

Chronic inflammation plays a crucial role in carcinogenesis. High levels of serum prostaglandin E2 and tissue overexpression of cyclooxygenase-2 (COX-2) have been described in breast, urinary, colorectal, prostate, and lung cancers as being involved in tumor initiation, promotion, progression, angiogenesis, and immunosuppression. Non-steroidal anti-inflammatory drugs (NSAIDs) are prescribed for several medical conditions to not only decrease pain and fever but also reduce inflammation by inhibiting COX and its product synthesis. To date, significant efforts have been made to better understand and clarify the interplay between cancer development, inflammation, and NSAIDs with a view toward addressing their potential for cancer management. This review provides readers with an overview of the potential use of NSAIDs and selective COX-2 inhibitors for breast cancer treatment, highlighting pre-clinical in vitro and in vivo studies employed to evaluate the efficacy of NSAIDs and their use in combination with other antineoplastic drugs.

System-level protein interaction network analysis and molecular dynamics study reveal interaction of ferulic acid with PTGS2 as a natural radioprotector

Ferulic acid is a crucial bioactive component of broccoli, wheat, and rice bran and is also an essential natural product that has undergone significant research. Ferulic acid's precise mode of action and effect on system-level protein networks have not been thoroughly investigated. An interactome was built using the STRING database and Cytoscape tools, utilizing 788 key proteins collected from PubMed literature to identify the ferulic acid-governed regulatory action on protein interaction network (PIN). The scale-free biological network of ferulic acid-rewired PIN is highly interconnected. We discovered 15 sub-modules using the MCODE tool for sub-modulization analysis and 153 enriched signaling pathways. Further, functional enrichment of top bottleneck proteins revealed the FoxO signaling pathway involved in enhancing cellular defense against oxidative stress. The selection of the critical regulatory proteins of the ferulic acid-rewired PIN was completed by performing analyses of topological characteristics such as GO term/pathways analysis, degree, bottleneck, molecular docking, and dynamics investigations. The current research derives a precise molecular mechanism for ferulic acid's action on the body. This in-depth in silico model would aid in understanding how ferulic acid origins its antioxidant and scavenging properties in the human body.Communicated by Ramaswamy H. Sarma.

Tumoricidal properties of thymoquinone on human colorectal adenocarcinoma cells via the modulation of autophagy

Colorectal cancer (CRC) is deadly anaplastic changes in the gastrointestinal tract with high-rate mortality. In recent years, the application of phytocompounds has been extended along with different therapeutic protocols. Here, we monitored the effects of Thymoquinone (TQ) on autophagy via mitochondrial function after modulation of the Wnt/β-catenin signaling pathway.Human colorectal adenocarcinoma HT-29 cells were treated with TQ (60 µM) and 15 µM Wnt3a inhibitor (LGK974) for 48 h. The survival rate was evaluated using an MTT assay. The expression of Wnt-related factors (c-Myc, and Axin), angiogenesis (VE-Cadherin), and mitophagy-related factors (PINK1, OPTN) was assessed using real-time PCR assay. Protein levels of autophagy factors (Beclin-1, LC3, and P62) were monitored using western blotting. Using flow cytometry analysis, the intracellular accumulation of Rhodamine 123 was evaluated. The migration properties were analyzed using a scratch wound healing assay.Data indicated that TQ can reduce the viability of HT-29 cells compared to the control cells (p < 0.05). The expression of VE-Cadherin was inhibited while the expression of PINK1 was induced in treated cells (p < 0.05). Both LGK974 and TQ-treated cells exhibited activation of autophagy flux (Beclin-1↑, LC3II/I↑, and p62↓) compared to the control group (p < 0.05). TQ can increase intracellular accumulation of Rhodamine 123, indicating the inhibition of efflux mechanisms in cancer cells. Along with these changes, the migration of cells was also reduced (p < 0.05).TQ is a potential phytocompound to alter the dynamic growth of human colorectal HT-29 cells via the modulation of autophagy, and mitophagy-related mechanisms.

Oroxylin A suppress LL-37 generated rosacea-like skin inflammation through the modulation of SIRT3-SOD2-NF-κB signaling pathway

Rosacea is a long-term inflammatory skin disease associated with the dysfunction of vascular and immunological systems. Treatment options for rosacea are difficult to implement. Oroxylin A(OA), a traditional Chinese medicine, has anti-inflammation effects in a variety of inflammatory diseases. However, it is not known that whether OA exerts protective effects against LL-37-induced rosacea. In this study, bioinformatics analyses showed that the mechanisms of rosacea and the pharmacological targets of OA were highly overlapped. Subsequently, it was shown that the administration of OA resulted in a notable amelioration of rosacea-like skin lesions, as evidenced by a reduction in immune cell infiltration, modulation of cytokine production, and inhibition of angiogenesis. Plus, it was shown that OA effectively suppressed the generation of ROS generated by LL-37, as well as the subsequent activation of NF-κB signaling pathway. To explore further, we found that OA inhibited LL-37-induced ROS production via SIRT3-SOD2 signaling pathway in keratinocytes. Based on the aforementioned evidence, it can be inferred that OA exhibits a mitigating effect on the inflammatory response in rosacea by modulating the SIRT3-SOD2-NF-κB signaling pathway.

Cellular and molecular antiproliferative effects in 2D monolayer and 3D-cultivated HT-29 cells treated with zerumbone

Zerumbone (ZER) is a phytochemical isolated from plants of the Zingiberaceae family. Numerous studies have demonstrated its diverse pharmacological properties, particularly its potent antitumorigenic activity. This study aimed to assess the antiproliferative effects of ZER on HT-29 cells cultivated in both two-dimensional (2D) monolayer and three-dimensional (3D) spheroid culture systems. The evaluation of growth (size), cell death, and cell cycle arrest in 3D spheroid HT-29 cells was correlated with mRNA expression data. Treatment of 2D cells revealed that ZER exhibited cytotoxicity at concentrations above 30 µM, and an IC50 of 83.54 µM (24-h post-ZER treatment) effectively suppressed cell migration. In the 3D model, ZER induced an increase in spheroid volume over a 72-h period attributed to disaggregation and reconfiguration of characteristic zones. Analysis of cell death demonstrated a significant rise in apoptotic cells after 24 h of ZER treatment, along with cell cycle arrest in the G1 phase. Furthermore, ZER treatment resulted in alterations in mRNA expression, affecting key signaling pathways involved in cell death (BCL2 and BBC3), endoplasmic reticulum stress (ERN1), DNA damage (GADD45A), cell cycle regulation (CDKN1A, NFKB1, MYC, and TP53), and autophagy (BECN1 and SQSTM1). These findings suggested that ZER holds promise as a potential candidate for the development of novel anticancer agents that can modulate crucial cell signaling pathways. Additionally, the use of the 3D culture system proved to be a valuable tool in our investigation.

Isothiocyanates Potentiate Tazemetostat-Induced Apoptosis by Modulating the Expression of Apoptotic Genes, Members of Polycomb Repressive Complex 2, and Levels of Tri-Methylating Lysine 27 at Histone 3 in Human Malignant Melanoma Cells

In this study, we utilized an in vitro model consisting of human malignant melanoma as well as non-tumorigenic immortalized keratinocyte cells with the aim of characterizing the therapeutic effectiveness of the clinical epigenetic drug Tazemetostat alone or in combination with various isothiocyanates. In doing so, we assessed markers of cell viability, apoptotic induction, and expression levels of key proteins capable of mediating the therapeutic response. Our data indicated, for the first time, that Tazemetostat caused a significant decrease in viability levels of malignant melanoma cells in a dose- and time-dependent manner via the induction of apoptosis, while non-malignant keratinocytes were more resistant. Moreover, combinatorial treatment protocols caused a further decrease in cell viability, together with higher apoptotic rates. In addition, a significant reduction in the Polycomb Repressive Complex 2 (PRC2) members [e.g., Enhancer of Zeste Homologue 2 (EZH2), Embryonic Ectoderm Development (EED), and suppressor of zeste 12 (SUZ12)] and tri-methylating lysine 27 at Histone 3 (H3K27me3) protein expression levels was observed, at least partially, under specific combinatorial exposure conditions. Reactivation of major apoptotic gene targets was determined at much higher levels in combinatorial treatment protocols than Tazemetostat alone, known to be involved in the induction of intrinsic and extrinsic apoptosis. Overall, we developed an optimized experimental therapeutic platform aiming to ensure the therapeutic effectiveness of Tazemetostat in malignant melanoma while at the same time minimizing toxicity against neighboring non-tumorigenic keratinocyte cells.

Tailored horseshoe-shaped nicotinonitrile scaffold as dual promising c-Met and Pim-1 inhibitors: Design, synthesis, SAR and in silico study

For the horseshoe tactic to succeed in inhibiting c-Met and Pim-1, the nicotinonitrile derivatives (2a-n) were produced in high quantities by coupling acetyl phenylpyrazole (1) with the proper aldehydes and ethyl cyanoacetate under basic conditions. Consistent basic and spectroscopic data (NMR, IR, Mass, and HPLC) supported the new products' structural findings. With IC50 potency in nanomolar ranges, these compounds had effectively repressed them, particularly compounds 2d and 2 h, with IC50 values below 200 nM. The most potent compounds (2d and 2 h) were tested for their antitumor effects against prostate (PC-3), colon (HCT-116), and breast (MDA-MB-231) and were evaluated in comparison to the anticancer drug tivantinib using the MTT assay. Similar to tivantinib, these compounds showed good antiproliferative properties against the HCT-116 tumor cells while having low cytotoxicity towards healthy fetal colon (FHC) cells. In the HCT-116 cell line, their ability to trigger the apoptotic cascade was also investigated by looking at the level of Bax and Bcl-2 as well as the activation of the proteolytic caspase cascade. When HCT-116 cells were exposed to compounds 2d and 2 h in comparison to the control, active caspase-3 levels increased. The HCT-116 cell line also upregulated Bcl-2 protein levels and downregulated Bax levels. Additionally, when treated with compound 2d, the HCT-116 cell cycle was primarily stopped at the S phase. Compared to the control, compound 2d treatment significantly inhibited the protein expression levels of c-Met and Pim-1 kinases in the treated HCT-116 cells. Thorough molecular modeling analyses, such as molecular docking and dynamic simulation, were performed to ascertain the binding mechanism and stability of the target compounds.

Bioactive compounds as potential alternative treatments to prevent cancer therapy-induced male infertility

About 8-12% of couples experience infertility, with male infertility being the cause in 50% of cases. Several congenital and acquired conditions, including chronic diseases and their treatments, can contribute to male infertility. Prostate cancer incidence increases annually by roughly 3%, leading to an increment in cancer treatments that have adverse effects on male fertility. To preserve male fertility post-cancer survival, conventional cancer treatments use sperm cryopreservation and hormone stimulation. However, these techniques are invasive, expensive, and unsuitable in prepubertal patients lacking mature sperm cells. Alternatively, nutritional therapies enriched with bioactive compounds are highlighted as non-invasive approaches to prevent male infertility that are easily implementable and cost-effective. In fact, curcumin and resveratrol are two examples of bioactive compounds with chemo-preventive effects at the testicular level. In this article, we summarize and discuss the literature regarding bioactive compounds and their mechanisms in preventing cancer treatment-induced male infertility. This information may lead to novel opportunities for future interventions.

Quinces (Cydonia oblonga, Chaenomeles sp., and Pseudocydonia sinensis) as Medicinal Fruits of the Rosaceae Family: Current State of Knowledge on Properties and Use

In recent years, the evaluation of many plant-derived compounds as potential new drugs or functional foods has become an active research topic. The morphological characteristics of quinces of the genera Cydonia sp., Chaenomeles sp., and Pseuocydonia sp. are largely similar, which is why these fruits are often confused. Although they have been appreciated in Asia for centuries as a valuable component of local ethnomedicine, they are less known in Western countries, and scientific knowledge about their health benefits remains fragmentary. This literature review summarizes studies on the content of chemical compounds responsible for the health-promoting and functional properties of the quince fruit. It focuses on the content of carotenoids, vitamins, minerals, and carboxylic acids, although the main emphasis is on the content and diversity of bioactive polyphenols, which are extremely abundant in these fruits. The quince fruits are rich in antioxidants and compounds with proven anti-inflammatory, anticancer, antiallergic, and immunomodulatory effects. Their phytochemicals effectively regulate glycemia and improve the blood lipid profile, suggesting potential antidiabetic and cardioprotective benefits. Analysis of chemical characteristics showed that the Chaenomeles fruits. are underestimated as functional food ingredients. Studies on the molecular effects of their bioactive compounds and species-specific genomic analyses are sorely lacking in the scientific literature.

Overview of the New Bioactive Heterocycles as Targeting Topoisomerase Inhibitors Useful Against Colon Cancer

Colorectal cancer (CRC) is the third most common cancer globally, with high mortality. Metastatic CRC is incurable in most cases, and multiple drug therapy can increase patients' life expectancy by 2 to 3 years. Efforts are being made to understand the relationship between topoisomerase enzymes and colorectal cancer. Some studies have shown that higher expression of these enzymes is correlated to a poor prognosis for this type of cancer. One of the primary drugs used in the treatment of CRC is Irinotecan, which can be used in monotherapy or, more commonly, in therapeutic schemes such as FOLFIRI (Fluorouracil, Leucovorin, and Irinotecan) and CAPIRI (Capecitabine and Irinotecan). Like Camptothecin, Irinotecan and other compounds have a mechanism of action based on the formation of a ternary complex with topoisomerase I and DNA providing damage to it, therefore leading to cell death. Thus, this review focused on the principal works published in the last ten years that demonstrate a correlation between the inhibition of different isoforms of topoisomerase and in vitro cytotoxic activity against CRC by natural products, semisynthetic and synthetic compounds of pyridine, quinoline, acridine, imidazoles, indoles, and metal complexes. The results revealed that natural compounds, semisynthetic and synthetic derivatives showed potential in vitro cytotoxicity against several colon cancer cell lines, and this activity was often accompanied by the ability to inhibit both isoforms of topoisomerase (I and II), highlighting that these enzymes can be promising targets for the development of new chemotherapy against CRC. Pyridine analogs were considered the most promising for this study, while the evaluation of the real potential of natural products was limited by the lack of information in their work. Moreover, the complexes, although promising, presented as the main limitation the lack of selectivity.

Enhanced Cytotoxicity and Antimelanoma Activity of Novel Semisynthetic Derivatives of Betulinic Acid with Indole Conjugation

The prevalence and severity of skin cancer, specifically malignant melanoma, among Caucasians remains a significant concern. Natural compounds from plants have long been explored as potential anticancer agents. Betulinic acid (BI) has shown promise in its therapeutic properties, including its anticancer effects. However, its limited bioavailability has hindered its medicinal applications. To address this issue, two recently synthesized semisynthetic derivatives, N-(2,3-indolo-betulinoyl)diglycylglycine (BA1) and N-(2,3-indolo-betulinoyl)glycylglycine (BA2), were compared with previously reported compounds N-(2,3-indolo-betulinoyl)glycine (BA3), 2,3-indolo-betulinic acid (BA4), and BI. These compounds were evaluated for their effects on murine melanoma cells (B164A5) using various in vitro assays. The introduction of an indole framework at the C2 position of BI resulted in an increased cytotoxicity. Furthermore, the cytotoxicity of compound BA4 was enhanced by conjugating its carboxylic group with an amino acid residue. BA2 and BA3, with glycine and glycylglycine residues at C28, exhibited approximately 2.20-fold higher inhibitory activity compared to BA4. The safety assessment of the compounds on human keratinocytes (HaCaT) has revealed that concentrations up to 10 µM slightly reduced cell viability, while concentrations of 75 µM resulted in lower cell viability rates. LDH leakage assays confirmed cell membrane damage in B164A5 cells when exposed to the tested compounds. BA2 and BA3 exhibited the highest LDH release, indicating their strong cytotoxicity. The NR assay revealed dose-dependent lysosome disruption for BI and 2,3-indolo-betulinic acid derivatives, with BA1, BA2, and BA3 showing the most cytotoxic effects. Scratch assays demonstrated concentration-dependent inhibition of cell migration, with BA2 and BA3 being the most effective. Hoechst 3342 staining revealed that BA2 induced apoptosis, while BA3 induced necrosis at lower concentrations, confirming their anti-melanoma properties. In conclusion, the semisynthetic derivatives of BI, particularly BA2 and BA3, show promise as potential candidates for further research in developing effective anti-cancer therapies.

Compounds targeting ferroptosis in breast cancer: progress and their therapeutic potential

In recent years, there has been a significant increase in the incidence of Breast cancer (BC), making it the most common cancer among women and a major threat to women's health. Consequently, there is an urgent need to discover new and effective strategies for treating BC. Ferroptosis, a novel form of cell death characterized by the accumulation of iron-dependent lipid reactive oxygen species, has emerged as a distinct regulatory pathway separate from necrosis, apoptosis, and autophagy. It is widely recognized as a crucial factor in the development and progression of cancer, offering a promising avenue for BC treatment. While significant progress has been made in understanding the mechanisms of ferroptosis in BC, drug development is still in its early stages. Numerous compounds, including phytochemicals derived from dietary sources and medicinal plants, as well as synthetic drugs (both clinically approved medications and laboratory reagents), have shown the ability to induce ferroptosis in BC cells, effectively inhibiting tumor growth. This comprehensive review aims to examine in detail the compounds that target ferroptosis in BC and elucidate their potential mechanisms of action. Additionally, the challenges associated with the clinical application of ferroptosis-inducing drugs are discussed, offering valuable insights for the development of novel treatment strategies for BC.

Avocado (Persea americana Mill) and its phytoconstituents: potential for cancer prevention and intervention

Dietary compounds, including fruits, vegetables, nuts, and spices, have been shown to exhibit anticancer properties due to their high concentrations of vitamins, minerals, fiber, and secondary metabolites, known as phytochemicals. Although emerging studies suggest that avocado (Persea americana Mill) displays antineoplastic properties in addition to numerous other health benefits, current literature lacks an updated comprehensive systematic review dedicated to the anticancer effects of avocado. This review aims to explore the cancer-preventive effects of avocados and the underlying molecular mechanisms. The in vitro studies suggest the various avocado-derived products and phytochemicals induced cytotoxicity, reduced cell viability, and inhibited cell proliferation. The in vivo studies revealed reduction in tumor number, size, and volume as well. The clinical studies demonstrated that avocado leaf extract increased free oxygen radical formation in larynx carcinoma tissue. Various avocado products and phytochemicals from the avocado fruit, including avocatin-B, persin, and PaDef defensin, may serve as viable cancer prevention and treatment options based on current literature. Despite many favorable outcomes, past research has been limited in scope, and more extensive and mechanism-based in vivo and randomized clinical studies should be performed before avocado-derived bioactive phytochemicals can be developed as cancer preventive agents.

Allyl Isothiocyanate Suppresses the Proliferation in Oral Squamous Cell Carcinoma via Mediating the KDM8/CCNA1 Axis

The dysregulated expression of cyclin genes can lead to the uncontrolled proliferation of cancer cells. Histone demethylase Jumonji-C domain-containing protein 5 (KDM8, JMJD5) and cyclin A1 (CCNA1) are pivotal in cell cycle progression. A promising candidate for augmenting cancer treatment is Allyl isothiocyanate (AITC), a natural dietary chemotherapeutic and epigenetic modulator. This study aimed to investigate AITC's impact on the KDM8/CCNA1 axis to elucidate its role in oral squamous cell carcinoma (OSCC) tumorigenesis. The expression of KDM8 and CCNA1 was assessed using a tissue microarray (TMA) immunohistochemistry (IHC) assay. In vitro experiments with OSCC cell lines and in vivo experiments with patient-derived tumor xenograft (PDTX) and SAS subcutaneous xenograft tumor models were conducted to explore AITC's effects on their expression and cell proliferation. The results showed elevated KDM8 and CCNA1 levels in the OSCC patient samples. AITC exhibited inhibitory effects on OSCC tumor growth in vitro and in vivo. Additionally, AITC downregulated KDM8 and CCNA1 expression while inducing histone H3K36me2 expression in oral cancer cells. These findings underscore AITC's remarkable anticancer properties against oral cancer, highlighting its potential as a therapeutic option for oral cancer treatment by disrupting the cell cycle by targeting the KDM8/CCNA1 axis.

Phytochemicals for the prevention and treatment of pancreatic cancer: Current progress and future prospects

Pancreatic cancer is the third leading cause of cancer-related deaths in the United States, owing to its aggressive nature and suboptimal treatment options, emphasizing the need for novel therapeutic approaches. Emerging studies have exhibited promising results regarding the therapeutic utility of plant-derived compounds (phytochemicals) in pancreatic cancer. The purpose of this review is to evaluate the potential of phytochemicals in the treatment and prevention of pancreatic cancer. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses was applied to collect articles for this review. Scholarly databases, including PubMed, Scopus and ScienceDirect, were queried for relevant studies using the following keywords: phytochemicals, phenolics, terpenoids, alkaloids, sulfur-containing compounds, in vitro, in vivo, clinical studies, pancreatic cancer, tumour, treatment and prevention. Aggregate results pooled from qualified studies indicate phytochemicals can inhibit pancreatic cancer cell growth or decrease tumour size and volume in animal models. These effects have been attributed to various mechanisms, such as increasing proapoptotic factors, decreasing antiapoptotic factors, or inducing cell death and cell cycle arrest. Notable signalling pathways modulated by phytochemicals include the rat sarcoma/mitogen activated protein kinase, wingless-related integration site/β-catenin and phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signal transduction pathways. Clinically, phytochemicals have been found to increase survival while being well-tolerated and safe, though research is scarce. While these promising results have produced great interest in this field, further in-depth studies are required to characterize the anticancer activities of phytochemicals before they can be utilized to prevent or treat pancreatic cancer in clinical practice.

Cucumis sativus (Cucurbitaceae) seed oil prevents benzo(a)pyrene-induced prostate cancer in vitro and in vivo

Despite enormous progress in modern medicine, prostate cancer (PCa) remains a major public health problem due to its high incidence and mortality. Although studies have shown in vitro antitumor effects of cucurbitacins from Cucumis sativus, the in vivo anticancer effect of the seed oil as a whole, has yet to be demonstrated. The present study evaluated the in vitro anticancer mechanisms of C. sativus (CS) seed oil and its possible chemopreventive potential on benzo(a)pyrene (BaP)-induced PCa in Wistar rat. In vitro cell growth, clone formation, cell death mechanism, cell adhesion and migration as well as expression of integrins β-1 and β-4 were assessed. In vivo PCa was induced in 56 male rats versus 8 normal control rats, randomized in normal (NOR) and negative (BaP) control groups which, received distilled water; the positive control group (Caso) was treated with casodex (13.5 mg/kg BW). One group received the total seed extract at the dose of 500 mg/kg BW; while the remaining three groups were treated with CS seed oil at 42.5, 85, and 170 mg/kg BW. The endpoints were: morphologically (prostate tumor weight and volume), biochemically (total protein, prostate specific antigen (PSA), oxidative stress markers such as MDA, GSH, catalase, and SOD) and histologically. As results, CS seed oil significantly and concentration-dependently reduced the DU145 prostate cancer cell growth and clone formation (optimum = 100 μg/mL). It slightly increased the number of apoptotic cells and inhibited the migration and invasion of DU145 cells, while it decreased their adhesion to immobilized collagen and fibrinogen. The expression of integrin β-1 and β-4 was increased in presence of 100 μg/mL CS oil. In vivo, the BaP significantly elevated the incidence of PC tumors (75%), the total protein and PSA levels, pro-inflammatory cytokines (TNF-α, IL-1, and IL-6) and MDA levels compared to NOR. CS seeds oil significantly counteracted the effect of BaP by decreasing significantly the PC incidence (12.5%), and increasing the level of antioxidant (SOD, GSH, and catalase) and anti-inflammatory cytokine IL-10 in serum. While in BaP group PCa adenocarninoma was the most representative neoplasm, rats treated with 85 and 170 mg/kg prevented it in the light of the casodex. It is conclude that CS may provide tumor suppressive effects in vitro and in vivo which makes it an interesting candidate to support the current treatment protocol.

An Exosome-Based Therapeutic Strategy Targeting Neuroinflammation in Alzheimer's Disease with Berberine and Palmatine

Introduction

Neuroinflammation is one of the major pathogeneses in Alzheimer's disease (AD) and mainly involves abnormal inflammatory activation of microglia by multiple pathological stimuli. The treatment of AD remains a major challenge due to the multifactorial characterization of AD and the inefficient ability of therapeutic drugs to permeate through the blood‒brain barrier (BBB). Accordingly, drug combination treatment and drug carrier delivery have become important therapeutic tools for the treatment of multifactorial diseases, especially AD.

Methods

Inflammatory cytokine levels in microglia, including NO, TNF-α, IL-1β, IL-4, and IL-10, were detected. The Morris water maze and object location task were used to investigate the learning and memory functions of APP/PS1 mice in different treatment groups. The number of neurons and plasticity of synapses were evaluated by immunofluorescence double labelling. Additionally, the ratio of β-amyloid plaques and the number of activated microglia were evaluated by immunofluorescence staining. The concentrations of β-amyloid plaques and inflammatory factors in the hippocampus were determined by ELISA. Microglia-derived exosomes (Exos) were extracted and purified by size exclusion chromatography. The distribution of exosomes and drugs was investigated in vitro and in vivo.

Results

Compared to single drug interventions, the combination of Ber and Pal (Ber/Pal) modulated microglial inflammatory cytokine levels. Ber/Pal promoted the recovery of learning and memory impairment in APP/PS1 mice. Immunofluorescence staining indicated that Ber/Pal restored neurons, inhibited Aβ plaque formation and microglial activation, and regulated the secretion of inflammatory factors. Exos promoted the accumulation of drugs in cells and tissues and improved the targeting of drugs across the BBB.

Conclusion

Ber/Pal could offer a synergistic and more comprehensive therapeutic effect in AD. Additionally, the microglia-derived Exos-Ber/Pal delivery system promoted the targeting and permeation of drugs into the brain, suggesting a creative strategy for targeting AD therapy by regulating neuroinflammation in microglial cells.

Combined Use of Immune Checkpoint Inhibitors and Phytochemicals as a Novel Therapeutic Strategy against Cancer

Immune checkpoint inhibitor (ICI) therapy has dramatically changed cancer treatment, opening novel opportunities to cure malignant diseases. To date, most prevalently targeted immune checkpoints are programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), with many others being under extensive investigations. However, according to available data, only a fraction of patients may respond to ICI therapy. Additionally, this therapy may cause severe adverse immune-related side effects, such as diarrhea, headache, muscle weakness, rash, hepatitis and leucopenia, although most of them are not fatal, they can affect the patient's treatment outcome and quality of life. On the other hand, growing evidence has shown that phytochemicals with anticancer effects may combine ICI therapy to augment the safety and effectiveness of the treatment against cancer while reducing the adverse side effects. In this review, we summarize the state of art in the various experiments and clinical application of ICIs plus phytochemicals, with a focus on their combined use as a novel therapeutic strategy to cure cancer.

Signaling pathways driving ocular malignancies and their targeting by bioactive phytochemicals

Ocular cancers represent a rare pathology. The American Cancer Society estimates that 3,360 cases of ocular cancer occur annually in the United States. The major types of cancers of the eye include ocular melanoma (also known as uveal melanoma), ocular lymphoma, retinoblastoma, and squamous cell carcinoma. While uveal melanoma is one of the primary intraocular cancers with the highest occurrence in adults, retinoblastoma remains the most common primary intraocular cancer in children, and squamous cell carcinoma presents as the most common conjunctival cancer. The pathophysiology of these diseases involves specific cell signaling pathways. Oncogene mutations, tumor suppressor mutations, chromosome deletions/translocations and altered proteins are all described as causal events in developing ocular cancer. Without proper identification and treatment of these cancers, vision loss, cancer spread, and even death can occur. The current treatments for these cancers involve enucleation, radiation, excision, laser treatment, cryotherapy, immunotherapy, and chemotherapy. These treatments present a significant burden to the patient that includes a possible loss of vision and a myriad of side effects. Therefore, alternatives to traditional therapy are urgently needed. Intercepting the signaling pathways for these cancers with the use of naturally occurring phytochemicals could be a way to relieve both cancer burden and perhaps even prevent cancer occurrence. This research aims to present a comprehensive review of the signaling pathways involved in various ocular cancers, discuss current therapeutic options, and examine the potential of bioactive phytocompounds in the prevention and targeted treatment of ocular neoplasms. The current limitations, challenges, pitfalls, and future research directions are also discussed.

Potential Chemopreventive Role of Pterostilbene in Its Modulation of the Apoptosis Pathway

Cancer incidence keeps increasing every year around the world and is one of the leading causes of death worldwide. Cancer has imposed a major burden on the human population, including the deterioration of physical and mental health as well as economic or financial loss among cancer patients. Conventional cancer treatments including chemotherapy, surgery, and radiotherapy have improved the mortality rate. However, conventional treatments have many challenges; for example, drug resistance, side effects, and cancer recurrence. Chemoprevention is one of the promising interventions to reduce the burden of cancer together with cancer treatments and early detection. Pterostilbene is a natural chemopreventive compound with various pharmacological properties such as anti-oxidant, anti-proliferative, and anti-inflammatory properties. Moreover, pterostilbene, due to its potential chemopreventive effect on inducing apoptosis in eliminating the mutated cells or preventing the progression of premalignant cells to cancerous cells, should be explored as a chemopreventive agent. Hence, in the review, we discuss the role of pterostilbene as a chemopreventive agent against various types of cancer via its modulation of the apoptosis pathway at the molecular levels.

EGFR-Targeted Liposomes Combined with Ginsenoside Rh2 Inhibit Triple-Negative Breast Cancer Growth and Metastasis

Triple-negative breast cancer (TNBC) remains the most challenging breast cancer subtype due to its lack of targeted therapies and poor prognosis. In order to treat patients with these tumors, efforts have been made to explore feasible targets. Epidermal growth factor receptor (EGFR)-targeted therapy is currently in clinical trials and regarded to be a promising treatment strategy. In this study, an EGFR-targeting nanoliposome (LTL@Rh2@Lipo-GE11) using ginsenoside Rh2 as a wall material was developed, in which GE11 was used as the EGFR-binding peptide to deliver more ginsenoside Rh2 and luteolin into TNBC. In comparison to non-targeted liposomes (Rh2@Lipo and LTL@Rh2@Lipo), the nanoliposomes LTL@Rh2@Lipo-GE11 demonstrated a high specificity to MDA-MB-231 cells that expressed a high level of EGFR both in vitro and in vivo, contributing to the strong inhibitory effects on the growth and migration of TNBC. These results suggest that LTL@Rh2@Lipo-GE11 is a prospective candidate for targeted therapy of TNBC, with a remarkable capability to inhibit tumor development and metastasis.

Evaluation of autophagy inhibition to combat cancer: (vanadium complex)-protein interactions, parameterization, and validation of a new force field

Autophagy has drawn attention from the scientific community, mainly because of its significant advantages over chemotherapeutic processes. One of these advantages is its direct action on cancer cells, avoiding possible side effects, unlike chemotherapy, which reaches tumor cells and affects healthy cells in the body, leading to a great loss in the quality of life of patients. In this way, it is known that vanadium complex (VC) [VO(oda)(phen)] has proven inhibition effect on autophagy process in pancreatic cancer cells. Keeping that in mind, molecular dynamics (MD) simulations can be considered excellent strategies to investigate the interaction of metal complexes and their biological targets. However, simulations of this type are strongly dependent on the appropriate choice of force field (FF). Therefore, this work proposes the development of AMBER FF parameters for VC, having a minimum energy structure as a starting point, obtained through DFT calculations with B3LYP/def2-TZVP level of theory plus ECP for the vanadium atom. An MD simulation in vacuum was performed to validate the developed FF. From the structural analyses, satisfying values of VC bond lengths and angles were obtained, where a good agreement with the experimental data and the quantum reference was found. The RMSD analysis showed an average of only 0.3%. Finally, we performed docking and MD (120 ns) simulations with explicit solvent between VC and PI3K. Overall, our findings encourage new parameterizations of metal complexes with significant biological applications, as well as allow to contribute to the elucidation of the complex process of autophagy.

Antioxidant Activity and Inhibition of Liver Cancer Cells' Growth of Extracts from 14 Marine Macroalgae Species of the Mediterranean Sea

Macroalgae exhibit beneficial bioactivities for human health. Thus, the aim of the present study was to examine the antioxidant and anticancer potential of 14 macroalgae species' extracts, namely, Gigartina pistillata, Gigartina teedei, Gracilaria gracilis, Gracilaria sp., Gracilaria bursa pastoris, Colpomenia sinuosa, Cystoseira amentacea, Cystoseira barbata, Cystoseira compressa, Sargassum vulgare, Padina pavonica, Codium fragile, Ulva intestinalis, and Ulva rigida, from the Aegean Sea, Greece. The antioxidant activity was assessed using DPPH, ABTS^•+, ^•OH, and O₂^•- radicals' scavenging assays, reducing power (RP), and protection from ROO^•-induced DNA plasmid damage assays. Moreover, macroalgae extracts' total polyphenol contents (TPCs) were assessed. Extracts' inhibition against liver HepG2 cancer cell growth was assessed using the XTT assay. The results showed that G. teedei extract's IC₅₀ was the lowest in DPPH (0.31 ± 0.006 mg/mL), ABTS^•+ (0.02 ± 0.001 mg/mL), ^•OH (0.10 ± 0.007 mg/mL), O₂^•- (0.05 ± 0.003 mg/mL), and DNA plasmid breakage (0.038 ± 0.002 mg/mL) and exhibited the highest RP (RP_0.5AU 0.24 ± 0.019 mg/mL) and TPC (12.53 ± 0.88 mg GAE/g dw). There was also a significant correlation between antioxidant activity and TPC. P. pavonica (IC₅₀ 0.93 ± 0.006 mg/mL) exhibited the highest inhibition against HepG2 cell growth. Conclusively, some of the tested extracts exhibited significant chemopreventive properties, and so they may be used for food products.

Comparison of In Vitro Antimelanoma and Antimicrobial Activity of 2,3-Indolo-betulinic Acid and Its Glycine Conjugates

Malignant melanoma is one of the most pressing problems in the developing world. New therapeutic agents that might be effective in treating malignancies that have developed resistance to conventional medications are urgently required. Semisynthesis is an essential method for improving the biological activity and the therapeutic efficacy of natural product precursors. Semisynthetic derivatives of natural compounds are valuable sources of new drug candidates with a variety of pharmacological actions, including anticancer ones. Two novel semisynthetic derivatives of betulinic acid-N-(2,3-indolo-betulinoyl)diglycylglycine (BA1) and N-(2,3-indolo-betulinoyl)glycylglycine (BA2)-were designed and their antiproliferative, cytotoxic, and anti-migratory activity against A375 human melanoma cells was determined in comparison with known N-(2,3-indolo-betulinoyl)glycine (BA3), 2,3-indolo-betulinic acid (BA4) and naturally occurring betulinic acid (BI). A dose-dependent antiproliferative effect with IC₅₀ values that ranged from 5.7 to 19.6 µM was observed in the series of all five compounds including betulinic acid. The novel compounds BA1 (IC₅₀ = 5.7 µM) and BA2 (IC₅₀ = 10.0 µM) were three times and two times more active than the parent cyclic structure B4 and natural BI. Additionally, compounds BA2, BA3, and BA4 possess antibacterial activity against Streptococcus pyogenes ATCC 19615 and Staphylococcus aureus ATCC 25923 with MIC values in the range of 13-16 µg/mL and 26-32 µg/mL, respectively. On the other hand, antifungal activity toward Candida albicans ATCC 10231 and Candida parapsilosis ATCC 22019 was found for compound BA3 with MIC 29 µg/mL. This is the first report of antibacterial and antifungal activity of 2,3-indolo-betulinic acid derivatives and also the first extended report on their anti-melanoma activity, which among others includes data on anti-migratory activity and shows the significance of amino acid side chain on the observed activity. The obtained data justify further research on the anti-melanoma and antimicrobial activity of 2,3-indolo-betulinic acid derivatives.

Phenolic Phytochemicals for Prevention and Treatment of Colorectal Cancer: A Critical Evaluation of In Vivo Studies

Colorectal cancer (CRC) is the third most diagnosed and second leading cause of cancer-related death worldwide. Limitations with existing treatment regimens have demanded the search for better treatment options. Different phytochemicals with promising anti-CRC activities have been reported, with the molecular mechanism of actions still emerging. This review aims to summarize recent progress on the study of natural phenolic compounds in ameliorating CRC using in vivo models. This review followed the guidelines of the Preferred Reporting Items for Systematic Reporting and Meta-Analysis. Information on the relevant topic was gathered by searching the PubMed, Scopus, ScienceDirect, and Web of Science databases using keywords, such as "colorectal cancer" AND "phenolic compounds", "colorectal cancer" AND "polyphenol", "colorectal cancer" AND "phenolic acids", "colorectal cancer" AND "flavonoids", "colorectal cancer" AND "stilbene", and "colorectal cancer" AND "lignan" from the reputed peer-reviewed journals published over the last 20 years. Publications that incorporated in vivo experimental designs and produced statistically significant results were considered for this review. Many of these polyphenols demonstrate anti-CRC activities by inhibiting key cellular factors. This inhibition has been demonstrated by antiapoptotic effects, antiproliferative effects, or by upregulating factors responsible for cell cycle arrest or cell death in various in vivo CRC models. Numerous studies from independent laboratories have highlighted different plant phenolic compounds for their anti-CRC activities. While promising anti-CRC activity in many of these agents has created interest in this area, in-depth mechanistic and well-designed clinical studies are needed to support the therapeutic use of these compounds for the prevention and treatment of CRC.

Plumbagin downregulates UHRF1, p-Akt, MMP-2 and suppresses survival, growth and migration of cervical cancer CaSki cells

Plumbagin is a natural compound known to impede growth of cancerous cells. However, anti-cervical cancer effects of plumbagin and its underlying molecular mechanism still remains elusive. In this study, plumbagin reduced the viability of CaSki cells in a concentration dependent manner and suppressed their colony formation potential. It led to G2/M phase arrest with downregulation of E2F1 and upregulation of p21. Plumbagin reduced mitochondrial membrane potential and concomitantly increased the percentage of apoptotic cells as revealed by annexin V-propidium iodide staining. Real Time PCR and western blotting confirmed that plumbagin induced apoptosis by reducing the expression of pAkt, procaspase 9 and full-length PARP. Furthermore, scratch assay showed that plumbagin suppressed migratory potential of CaSki cells which could be due to the reduced expression and activity of MMP-2 and upregulation of TIMP2. Interestingly, plumbagin also downregulated UHRF1 expression. Transient silencing of UHRF1 like plumbagin, induced G2/M phase arrest, enhanced apoptosis and suppressed metastasis of CaSki cells suggesting the role of UHRF1 in mediating anti-cancer activities of plumbagin. Plumbagin at IC₂₀ (1 μM) interacted synergistically with cisplatin and reduced its IC₅₀ value by 13.23 fold with improved effectivity as revealed by augmented apoptosis in CaSki cells.

Maslinic acid exerts anticancer effects by targeting cancer hallmarks

BACKGROUND

Natural products have long been regarded as a source of anticancer compounds with low toxicity. Evidence revealed that maslinic acid (MA), a widely distributed pentacyclic triterpene in common foodstuffs, exhibited pronounced inhibitory effects against various cancer cell lines. Most cancer cells thrive by acquiring cancer hallmarks, as coined by Hanahan and Weinberg in 2000 and 2011.

PURPOSE

This represents the first systematic review concerning the anticancer properties of MA as these cancer hallmarks are targeted. It aims to summarize the antineoplastic activities of MA, discuss the diverse mechanisms of action based on the effects of MA exerted on each hallmark.

METHODS

A comprehensive literature search was conducted using the search terms "maslinic," "cancer," "tumor," and "neoplasm," to retrieve articles from the databases MEDLINE, EMBASE, Web of Science, and Scopus published up to September 2022. Study selection was conducted by three reviewers independently from title and abstract screening until full-text evaluation. Data extraction was done by one reviewer and counterchecked by the second reviewer.

RESULTS

Of the 330 articles assessed, 40 papers met the inclusion criteria and revealed that MA inhibited 16 different cancer cell types. MA impacted every cancer hallmark by targeting multiple pathways.

CONCLUSION

This review provides insights regarding the inhibitory effects of MA against various cancers and its remarkable biological properties as a pleiotropic bioactive compound, which encourage further investigations.

Resveratrol, Epigallocatechin Gallate and Curcumin for Cancer Therapy: Challenges from Their Pro-Apoptotic Properties

Plant-derived bioactive compounds are gaining wide attention for their multiple health-promoting activities and in particular for their anti-cancer properties. Several studies have highlighted how they can prevent cancer initiation and progression, improve the effectiveness of chemotherapy, and, in some cases, limit some of the side effects of chemotherapy agents. In this paper, we provide an update of the literature on the anti-cancer effects of three extensively studied plant-derived compounds, namely resveratrol, epigallocatechin gallate, and curcumin, with a special focus on the anti-cancer molecular mechanisms inducing apoptosis in the major types of cancers globally.

Chemopreventive and Anticancer Role of Resveratrol against Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most prevailing and aggressive head and neck cancers, featuring high morbidity and mortality. The available conventional treatments suffer from several adverse effects and are often inefficient in terms of their survival rates. Thus, seeking novel therapeutic agents and adjuvants is of the utmost importance for modern society. Natural polyphenolic compounds have recently emerged as promising chemopreventive and anticancer agents. Specifically, the natural compound resveratrol (RSV) has recently gained momentum for this purpose. RSV is useful for treating OSCC due to its antiproliferative, antimetastatic, and proapoptotic effects. Additionally, RSV acts against tumor cells while synergically cooperating with chemotherapeutics, overcoming drug resistance phenomena. Despite these wide-spectrum effects, there are few specific investigations regarding RSV's effects against OSCC animal models that consider different routes and vehicles for the administration of RSV. Interestingly, an injectable RSV-loaded liposome-based formulation was proven to be effective against both in vitro and in vivo OSCC models, demonstrating that the development of RSV-loaded drug delivery systems for systemic and/or loco-regional applications may be the turning point in oral cancer treatment, leading to benefits from both RSV's properties as well as from targeted delivery. Given these premises, this review offers a comprehensive overview of the in vitro and in vivo effects of RSV and its main derivative, polydatin (PD), against OSCC-related cell lines and animal models, aiming to guide the scientific community in regard to RSV and PD use in the treatment of oral precancerous and cancerous lesions.

8-paradol from ginger exacerbates PINK1/Parkin mediated mitophagy to induce apoptosis in human gastric adenocarcinoma

Gastric cancer (GC) occurs in the gastric mucosa, and its high morbidity and mortality make it an international health crisis. Therefore, novel drugs are needed for its treatment. The use of natural products and their components in cancer treatments has shown promise. Therefore, this study aimed to evaluate the effect of 8-paradol, a phenolic compound isolated from ginger (Zingiber officinale Roscoe), on GC and determine its underlying mechanisms of action. In this study, repeated column chromatography was conducted on ginger EtOH extract to isolate gingerol and its derivatives. The cytotoxicity of the eight ginger compounds underwent a (3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide) tetrazolium reduction (MTT) assay. 8-paradol showed the most potent cytotoxicity effect among the isolated ginger compounds. The underlying mechanism by which 8-paradol regulated specific proteins in AGS cells was evaluated by proteomic analysis. To validate the predicted mechanisms, AGS cells and thymus-deficient nude mice bearing AGS xenografts were used as in vitro and in vivo models of GC, respectively. The results showed that the 8-paradol promoted PINK1/Parkin-associated mitophagy, mediating cell apoptosis. Additionally, the inhibition of mitophagy by chloroquine (CQ) ameliorated 8-paradol-induced mitochondrial dysfunction and apoptosis, supporting a causative role for mitophagy in the 8-paradol-induced anticancer effect. Molecular docking results revealed the molecular interactions between 8-paradol and mitophagy-/ apoptosis-related proteins at the atomic level. Our study provides strong evidence that 8-paradol could act as a novel potential therapeutic agent to suppress the progression of GC by targeting mitophagy pathway.

Diverse Neutrophil Functions in Cancer and Promising Neutrophil-Based Cancer Therapies

Neutrophils represent the most abundant cell type of leukocytes in the human blood and have been considered a vital player in the innate immune system and the first line of defense against invading pathogens. Recently, several studies showed that neutrophils play an active role in the immune response during cancer development. They exhibited both pro-oncogenic and anti-tumor activities under the influence of various mediators in the tumor microenvironment. Neutrophils can be divided into several subpopulations, thus contradicting the traditional concept of neutrophils as a homogeneous population with a specific function in the innate immunity and opening new horizons for cancer therapy. Despite the promising achievements in this field, a full understanding of tumor-neutrophil interplay is currently lacking. In this review, we try to summarize the current view on neutrophil heterogeneity in cancer, discuss the different communication pathways between tumors and neutrophils, and focus on the implementation of these new findings to develop promising neutrophil-based cancer therapies.

Phytochemicals as Chemo-Preventive Agents and Signaling Molecule Modulators: Current Role in Cancer Therapeutics and Inflammation

Cancer is one of the deadliest non communicable diseases. Numerous anticancer medications have been developed to target the molecular pathways driving cancer. However, there has been no discernible increase in the overall survival rate in cancer patients. Therefore, innovative chemo-preventive techniques and agents are required to supplement standard cancer treatments and boost their efficacy. Fruits and vegetables should be tapped into as a source of compounds that can serve as cancer therapy. Phytochemicals play an important role as sources of new medication in cancer treatment. Some synthetic and natural chemicals are effective for cancer chemoprevention, i.e., the use of exogenous medicine to inhibit or impede tumor development. They help regulate molecular pathways linked to the development and spread of cancer. They can enhance antioxidant status, inactivating carcinogens, suppressing proliferation, inducing cell cycle arrest and death, and regulating the immune system. While focusing on four main categories of plant-based anticancer agents, i.e., epipodophyllotoxin, camptothecin derivatives, taxane diterpenoids, and vinca alkaloids and their mode of action, we review the anticancer effects of phytochemicals, like quercetin, curcumin, piperine, epigallocatechin gallate (EGCG), and gingerol. We examine the different signaling pathways associated with cancer and how inflammation as a key mechanism is linked to cancer growth.

Ferulic Acid: A Natural Phenol That Inhibits Neoplastic Events through Modulation of Oncogenic Signaling

Despite the immense therapeutic advances in the field of health sciences, cancer is still to be found among the global leading causes of morbidity and mortality. Ethnomedicinally, natural bioactive compounds isolated from various plant sources have been used for the treatment of several cancer types and have gained notable attention. Ferulic acid, a natural compound derived from various seeds, nuts, leaves, and fruits, exhibits a variety of pharmacological effects in cancer, including its proapoptotic, cell-cycle-arresting, anti-metastatic, and anti-inflammatory activities. This review study presents a thorough overview of the molecular targets and cellular signaling pathways modulated by ferulic acid in diverse malignancies, showing high potential for this phenolic acid to be developed as a candidate agent for novel anticancer therapeutics. In addition, current investigations to develop promising synergistic formulations are also discussed.

Synergistically Anti-Multiple Myeloma Effects: Flavonoid, Non-Flavonoid Polyphenols, and Bortezomib

Multiple myeloma (MM) is a clonal plasma cell tumor originating from a post-mitotic lymphoid B-cell lineage. Bortezomib(BTZ), a first-generation protease inhibitor, has increased overall survival, progression-free survival, and remission rates in patients with MM since its clinical approval in 2003. However, the use of BTZ is challenged by the malignant features of MM and drug resistance. Polyphenols, classified into flavonoid and non-flavonoid polyphenols, have potential health-promoting activities, including anti-cancer. Previous preclinical studies have demonstrated the anti-MM potential of some dietary polyphenols. Therefore, these dietary polyphenols have the potential to be alternative therapies in anti-MM treatment regimens. This systematic review examines the synergistic effects of flavonoids and non-flavonoid polyphenols on the anti-MM impacts of BTZ. Preclinical studies on flavonoids and non-flavonoid polyphenols-BTZ synergism in MM were collected from PubMed, Web of Science, and Embase published between 2008 and 2020. 19 valid preclinical studies (Published from 2008 to 2020) were included in this systematic review. These studies demonstrated that eight flavonoids (icariin, icariside II, (-)-epigallocatechin-3-gallate, scutellarein, wogonin, morin, formononetin, daidzin), one plant extract rich in flavonoids (Punica granatum juice) and four non-flavonoid polyphenols (silibinin, resveratrol, curcumin, caffeic acid) synergistically enhanced the anti-MM effect of BTZ. These synergistic effects are mediated through the regulation of cellular signaling pathways associated with proliferation, apoptosis, and drug resistance. Given the above, flavonoids and non-flavonoid polyphenols can benefit MM patients by overcoming the challenges faced in BTZ treatment. Despite the positive nature of this preclinical evidence, some additional investigations are still needed before proceeding with clinical studies. For this purpose, we conclude by providing some suggestions for future research directions.

Naringenin suppresses epithelial ovarian cancer by inhibiting proliferation and modulating gut microbiota

BACKGROUND

Ovarian cancer has the highest mortality among all gynecological malignancies; currently, no effective therapeutics are available for its treatment. Naringenin has been shown to inhibit the progression of various cancers, but its inhibitory effect on ovarian cancer remains unknown.

PURPOSE

This study aimed to evaluate the inhibitory effects of naringenin on ovarian cancer and elucidate the underlying mechanisms.

METHODS

Cancer cell proliferation was detected by cell counting kit-8 and crystal violet assays, and the migration capability was determined by wound healing and transwell assays. Western blotting and immunohistochemistry assays were employed to determine the expression levels of the epidermal growth factor receptor, phosphatidylinositol 3-kinase (PI3K) and cyclin D1 in vitro and in vivo, respectively. An ES-2 xenograft nude mouse model was established for the in vivo experiments, and fecal samples were collected for intestinal microbiota analysis by 16S rDNA sequencing.

RESULTS

Naringenin suppressed the proliferation and migration of A2780 and ES-2 cancer cell lines and downregulated PI3K in vitro. In animal experiments, naringenin treatment significantly decreased the tumor weight and volume, and oral administration exhibited greater effects than intraperitoneal injection. Additionally, naringenin treatment ameliorated the population composition of the microbiota in animals with ovarian cancer and significantly increased the abundances of Alistipes and Lactobacillus.

CONCLUSION

Naringenin suppresses epithelial ovarian cancer by inhibiting PI3K pathway expression and ameliorating the gut microbiota, and the oral route is more effective than parenteral administration.

Chalcone-Acridine Hybrid Suppresses Melanoma Cell Progression via G2/M Cell Cycle Arrest, DNA Damage, Apoptosis, and Modulation of MAP Kinases Activity

This study was focused on investigating the antiproliferative effects of chalcone hybrids in melanoma cancer cells. Among seven chalcone hybrids, the chalcone-acridine hybrid 1C was the most potent and was selected for further antiproliferative mechanism studies. This in vitro study revealed the potent antiproliferative effect of 1C via cell cycle arrest and apoptosis induction. Cell cycle arrest at the G2/M phase was associated with modulation of expression or phosphorylation of specific cell cycle-associated proteins (cyclin B1, p21, and ChK1), tubulins, as well as with the activation of the DNA damage response pathway. Chalcone 1C also induced apoptosis accompanied by mitochondrial dysfunction evidenced by a decrease in mitochondrial membrane potential, increase in Bax/Bcl-xL ratio and cytochrome c release followed by caspase 3/7 activation. In addition, increased phosphorylation of MAP kinases (Erk1/2, p38 and JNK) was observed in chalcone 1C-treated melanoma cells. The strong antiproliferative activities of this chalcone-acridine hybrid suggest that it may be useful as an antimelanoma agent in humans.

Anticancer Properties of Plectranthus ornatus-Derived Phytochemicals Inducing Apoptosis via Mitochondrial Pathway

Since cancer treatment by radio- and chemotherapy has been linked to safety concerns, there is a need for new and alternative anticancer drugs; as such, compounds isolated from plants represent promising candidates. The current study investigates the anticancer features of halimane (11R*,13E)-11-acetoxyhalima-5,13-dien-15-oic acid (HAL) and the labdane diterpenes 1α,6β-diacetoxy-8α,13R*-epoxy-14-labden-11-one (PLEC) and forskolin-like 1:1 mixture of 1,6-di-O-acetylforskolin and 1,6-di-O-acetyl-9-deoxyforskolin (MRC) isolated from Plectranthus ornatus in MCF7 and FaDu cancer cell lines. Cytotoxicity was assessed by MTT assay, ROS production by Di-chloro-dihydro-fluorescein diacetate assay (DCFH) or Red Mitochondrial Superoxide Indicator (MitoSOX) and Mitochondrial Membrane Potential (MMP) by fluorescent probe JC-1 (5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine iodide). In addition, the relative amounts of mitochondrial DNA (mtDNA) were determined using quantitative Real-Time-PCR (qRT-PCR) and damage to mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) by semi-long run quantitative Real-Time-PCR (SLR-qRT-PCR). Gene expression was determined using Reverse-Transcription-qPCR. Caspase-3/7 activity by fluorescence was assessed. Assessment of General In Vivo Toxicity has been determined by Brine Shrimp Lethality Bioassay. The studied HAL and PLEC were found to have a cytotoxic effect in MCF7 with IC₅₀ = 13.61 µg/mL and IC₅₀ = 17.49 µg/mL and in FaDu with IC₅₀ = 15.12 µg/mL and IC₅₀ = 32.66 µg/mL cancer cell lines. In the two tested cancer cell lines, the phytochemicals increased ROS production and mitochondrial damage in the ND1 and ND5 gene regions and reduced MMP (ΔΨm) and mitochondrial copy numbers. They also changed the expression of pro- and anti-apoptotic genes (Bax, Bcl-2, TP53, Cas-3, Cas-8, Cas-9, Apaf-1 and MCL-1). Studies demonstrated increase in caspase 3/7 activity in tested cancer cell lines. In addition, we showed no toxic effect in in vivo test for the compounds tested. The potential mechanism of action may have been associated with the induction of apoptosis in MCF7 and FaDu cancer cells via the mitochondrial pathway; however, further in vivo research is needed to understand the mechanisms of action and potential of these compounds.

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.

Food-Borne Chemical Carcinogens and the Evidence for Human Cancer Risk

Commonly consumed foods and beverages can contain chemicals with reported carcinogenic activity in rodent models. Moreover, exposures to some of these substances have been associated with increased cancer risks in humans. Food-borne carcinogens span a range of chemical classes and can arise from natural or anthropogenic sources, as well as form endogenously. Important considerations include the mechanism(s) of action (MoA), their relevance to human biology, and the level of exposure in diet. The MoAs of carcinogens have been classified as either DNA-reactive (genotoxic), involving covalent reaction with nuclear DNA, or epigenetic, involving molecular and cellular effects other than DNA reactivity. Carcinogens are generally present in food at low levels, resulting in low daily intakes, although there are some exceptions. Carcinogens of the DNA-reactive type produce effects at lower dosages than epigenetic carcinogens. Several food-related DNA-reactive carcinogens, including aflatoxins, aristolochic acid, benzene, benzo[a]pyrene and ethylene oxide, are recognized by the International Agency for Research on Cancer (IARC) as causes of human cancer. Of the epigenetic type, the only carcinogen considered to be associated with increased cancer in humans, although not from low-level food exposure, is dioxin (TCDD). Thus, DNA-reactive carcinogens in food represent a much greater risk than epigenetic carcinogens.

Eumelanin protects the liver against diethylnitrosamine-induced liver injury

This study aims to evaluate in vivo protective effects of eumelanin (EU) on diethylnitrosamine (DEN)-induced liver injury. Wistar albino male rats were divided into 6 groups (n = 6), Control, DMSO, DEN, DEN + EU10, DEN + EU15, and DEN + EU20. Animals in the DEN group were injected i.p a single dose of 200 mg/kg DEN, DEN + EU10 group was given 10 mg/kg EU, DEN + EU15 group was given 15 mg/kg, DEN + EU20 group was given 20 mg/kg EU for a week. The results showed that there was no significant difference in vessel volume density between the groups. Inflammatory cell infiltration, hydropic degeneration, and necrotic cells were observed in the DEN group, and these histopathological changes were significantly reduced in all treatment groups. Although there was a low intensity of PAS-positive staining in the DEN groups, moderate staining was observed in the treatment groups. While Caspase-3, PCNA, TNF-α, and IL-6 expressions increased in the DEN group, their expressions decreased in the EU-treated groups. DEN increased AST, ALT, and MDA levels and decreased CAT levels. In particular, the EU10 dose significantly improved these parameters. The present study revealed that eumelanin has protective effects against DEN-induced liver injury.

Ruellia tuberosa Ethyl Acetate Leaf Extract Induces Apoptosis and Cell Cycle Arrest in Human Breast Cancer Cell Line, MCF-7

Ruellia tuberosa L. has been previously shown to possess antioxidant and antiproliferative activities on cancer cells but its underlying mechanisms are largely unknown. This study aimed to elucidate the mode of action underlying this inhibitory effect on MCF-7 using ethyl acetate extract obtained after liquid-liquid partition of methanol crude extract. Antiproliferative effect of R. tuberosa ethyl acetate leaf extract (RTEAL) was evaluated using MTT assay. Its ability to induce apoptosis was assessed by DNA ladder formation, JC-1, Annexin V, and methylene blue staining assays. Perturbation of cell cycle progression was determined using flow cytometry. RTEAL was found to selectively inhibit the proliferation of MCF-7 cells with the IC50 value of 28 µg/mL. Morphological changes such as nuclear fragmentation and chromatin condensation were observed although DNA laddering was undetected in agarose gel. RTEAL-induced apoptotic pathways by inhibiting the expression of anti-apoptotic BCL-2 while upregulating pro-apoptotic BAX, caspase 7 and caspase 8. RTEAL also caused cell cycle arrests at the S and G2/M phase and dysregulation of cell cycle regulators. These findings collectively demonstrate that RTEAL extract inhibited cell growth by inducing apoptosis and cell cycle arrest, suggesting its therapeutic potential against breast cancer.

Phytochemicals for the Prevention and Treatment of Renal Cell Carcinoma: Preclinical and Clinical Evidence and Molecular Mechanisms

Simple Summary

Renal cell carcinoma (RCC) is the most frequently diagnosed kidney cancer. Once RCC metastasizes, successful treatment is difficult to achieve. There is an apparent need for novel approaches to prevent and treat RCC. Phytochemicals are naturally derived compounds gaining increasing scientific interest due to their cancer preventive and chemotherapeutic properties. These phytochemicals have been shown to exhibit a multitude of anticancer effects against RCC. In this systematic review, we critically evaluate the potential these natural compounds possess for the prevention and treatment of RCC and discuss the future implications this may have in the fight against kidney cancer.

Abstract

Renal cell carcinoma (RCC) is associated with about 90% of renal malignancies, and its incidence is increasing globally. Plant-derived compounds have gained significant attention in the scientific community for their preventative and therapeutic effects on cancer. To evaluate the anticancer potential of phytocompounds for RCC, we compiled a comprehensive and systematic review of the available literature. Our work was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. The literature search was performed using scholarly databases such as PubMed, Scopus, and ScienceDirect and keywords such as renal cell carcinoma, phytochemicals, cancer, tumor, proliferation, apoptosis, prevention, treatment, in vitro, in vivo, and clinical studies. Based on in vitro results, various phytochemicals, such as phenolics, terpenoids, alkaloids, and sulfur-containing compounds, suppressed cell viability, proliferation and growth, showed cytotoxic activity, inhibited invasion and migration, and enhanced the efficacy of chemotherapeutic drugs in RCC. In various animal tumor models, phytochemicals suppressed renal tumor growth, reduced tumor size, and hindered angiogenesis and metastasis. The relevant antineoplastic mechanisms involved upregulation of caspases, reduction in cyclin activity, induction of cell cycle arrest and apoptosis via modulation of a plethora of cell signaling pathways. Clinical studies demonstrated a reduced risk for the development of kidney cancer and enhancement of the efficacy of chemotherapeutic drugs. Both preclinical and clinical studies displayed significant promise of utilizing phytochemicals for the prevention and treatment of RCC. Further research, confirming the mechanisms and regulatory pathways, along with randomized controlled trials, are needed to establish the use of phytochemicals in clinical practice.

Synthesis and cytotoxicity of betulin and betulinic acid derived 30-oxo-amides

Betulin and betulinic acid derived 30-oxo-amides were prepared by hydroboration, subsequent oxidation and amidation; these novel compounds were screened for their cytotoxic activity by SRB assays. All of the compounds showed significant cytotoxic activity for different human tumor cell lines. Small changes in the structure, however, resulted in significant changes in the cytotoxicity of the compounds. Of special interest were compounds 11 and 12, each holding an extra ethylenediamine moiety. These C-30 amides which showed low EC₅₀ values, and both of them acted mainly by apoptosis.

Berberine and Oligomeric Proanthocyanidins Exhibit Synergistic Efficacy Through Regulation of PI3K-Akt Signaling Pathway in Colorectal Cancer

Background

Naturally occurring dietary botanicals offer time-tested safety and anti-cancer efficacy, and a combination of certain compounds has shown to overcome the elusive chemotherapeutic resistance, which is of great significance for improving the mortality of patients with colorectal cancer (CRC). Accordingly, herein, we hypothesized that berberine (BBR) and oligomeric proanthocyanidins (OPCs) might regulate synergistically multiple oncogenic pathways to exert a superior anti-cancer activity in CRC.

Methods

We performed a series of cell culture studies, followed by their interrogation in patient-derived organoids to evaluate the synergistic effect of BBR and OPCs against CRC. In addition, by performing whole genome transcriptomic profiling we identified the key targeted genes and pathways regulated by the combined treatment.

Results

We first demonstrated that OPCs facilitated enhanced cellular uptake of BBR in CRC cells by measuring the fluorescent signal of BBR in cells treated individually or their combination. The synergism between BBR and OPCs were investigated in terms of their anti-tumorigenic effect on cell viability, clonogenicity, migration, and invasion. Furthermore, the combination treatment potentiated the cellular apoptosis in an Annexin V binding assay. Transcriptomic profiling identified oncogene MYB in PI3K-AKT signaling pathway might be critically involved in the anti-tumorigenic properties of the combined treatment. Finally, we successfully validated these findings in patient-derived CRC tumor organoids.

Conclusions

Collectively, we for the first time demonstrate that a combined treatment of BBR and OPCs synergistically promote the anti-tumorigenic properties in CRC possibly through the regulation of cellular apoptosis and oncogene MYB in the PI3K-Akt signaling pathway.

Multiple Effects of Resveratrol on Osteosarcoma Cell Lines

Osteosarcoma (OS) is the most common primary bone sarcoma affecting the life of pediatric patients. The clinical treatment faces numerous difficulties, including the adverse effects of chemotherapies, chemoresistance, and recurrences. In this study, the effects of resveratrol (RSV), a natural polyphenol, on OS cell lines were investigated to evaluate its action as an adjuvant therapy to the current chemotherapy regimens. RSV exhibited multiple tumor-suppressing activities on OS cell lines, inducing a series of critical events. We found (1) a cell growth inhibition due to an increase in cell distress, which was, in part, due to the involvement of the AKT and caspase-3 pathways, (2) an increase in cellular differentiation due to major gene expression levels of the osteoblastic differentiation genes, (3) an inhibition of IL-6 secretion due to an epigenetic effect on the IL-6 promoter, and (4) an inhibition of OS cells migration related to the decrease in IL-8 secretion levels due to an epigenetic effect on its promoter. Finally, the cotreatment of RSV with doxorubicin and cisplatin increased their cytotoxic effect on OS cells. Although further investigations are mandatory, it seems RSV might be a promising therapeutic adjuvant agent for OS cell treatment, exerting an antitumor effect when combined with chemotherapy.

Quercetin- and rutin-based nano-formulations for cancer treatment: A systematic review of improved efficacy and molecular mechanisms

BACKGROUND

Natural products, with incredible chemical diversity, have been widely studied for their antitumor potential. Quercetin (QU) and quercetin glycoside (rutin), both polyphenolic flavonoids, stick out amongst the natural products, through various studies. Rutin (RU) and its aglycone (QU) have various biological properties that include antioxidant, anti-inflammatory, and anticarcinogenic activities. However, several side effects have restricted the efficacy of these polyphenolic flavonoids, which makes it necessary to use new strategies involving low and pharmacological doses of QU and RU, either alone or in combination with other anticancer drugs.

PURPOSE

The aim of this study is to present a comprehensive and critical evaluation of the anticancer ability of different nano-formulations of RU and QU for improved treatment of various malignancies.

METHODS

Studies were recognized via systematic searches of ScienceDirect, PubMed, and Scopus databases. Eligibility checks were conducted based upon predefined selection criteria. Ninety articles were included in this study.

RESULTS

There was conclusive evidence for the association between anticancer activity and treatment with RU or QU. Furthermore, studies indicated that nano-formulations of RU and QU have greater anticancer activities in comparison to either agent alone, which leads to increased efficiency for treating cancer.

CONCLUSION

The results of this systematic review demonstrate the anticancer activities of nano-formulations of RU and QU and their molecular mechanisms through preclinical studies. This paper also attempts to contribute to further research by addressing the current limitations/challenges and proposing additional studies to realize the full potential of RU- and QU-based formulations for cancer treatment.

Pediatric acute lymphoblastic leukemia management using multitargeting bioactive natural compounds: A systematic and critical review

Pediatric acute lymphoblastic leukemia (pALL), a malignancy of the lymphoid line of blood cells, accounts for a large percentage of all childhood leukemia cases. Although the 5-year survival rate for children with ALL has greatly improved over years, using chemotherapeutics as its first-line treatment still causes short- and long-term side effects. Furthermore, induction of toxicity and resistance, as well as the high cost, limit their application. Phytochemicals, with remarkable cancer preventive and chemotherapeutic characteristics, may serve as old solutions to new challenges. Bioactive plant secondary metabolites have exhibited promising antileukemic and adjunctive effects by targeting various molecular processes, including autophagy, cell cycle, angiogenesis, and extrinsic/intrinsic apoptotic pathways. Although numerous reports have shown that numerous plant secondary metabolites can interfere with the progression of malignancies, including leukemia, there was no comprehensive review article on the effect of phytochemicals on pALL. This systematic review aims to provide critical and cohesive analysis of the potential of various naturally-occurring metabolites in the management of pALL with the understanding of underlying molecular and cellular mechanisms of action.