Increase of phosphatase and tensin homolog by silymarin to inhibit human pharynx squamous cancer

Exploiting new strategies in combating head and neck carcinoma: A comprehensive review on phytochemical approaches passing through PI3K/Akt/mTOR signaling pathway

Recently, malignant neoplasms have growingly caused human morbidity and mortality. Head and neck cancer (HNC) constitutes a substantial group of malignancies occurring in various anatomical regions of the head and neck, including lips, mouth, throat, larynx, nose, sinuses, oropharynx, hypopharynx, nasopharynx, and salivary glands. The present study addresses the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway as a possible therapeutic target in cancer therapy. Finding new multitargeting agents capable of modulating PI3K/Akt/mTOR and cross-linked mediators could be viewed as an effective strategy in combating HNC. Recent studies have introduced phytochemicals as multitargeting agents and rich sources for finding and developing new therapeutic agents. Phytochemicals have exhibited immense anticancer effects, including targeting different stages of HNC through the modulation of several signaling pathways. Moreover, phenolic/polyphenolic compounds, alkaloids, terpenes/terpenoids, and other secondary metabolites have demonstrated promising anticancer activities because of their diverse pharmacological and biological properties like antiproliferative, antineoplastic, antioxidant, and anti-inflammatory activities. The current review is mainly focused on new therapeutic strategies for HNC passing through the PI3K/Akt/mTOR pathway as new strategies in combating HNC.

Natural compounds as lactate dehydrogenase inhibitors: potential therapeutics for lactate dehydrogenase inhibitors-related diseases

Lactate dehydrogenase (LDH) is a crucial enzyme involved in energy metabolism and present in various cells throughout the body. Its diverse physiological functions encompass glycolysis, and its abnormal activity is associated with numerous diseases. Targeting LDH has emerged as a vital approach in drug discovery, leading to the identification of LDH inhibitors among natural compounds, such as polyphenols, alkaloids, and terpenoids. These compounds demonstrate therapeutic potential against LDH-related diseases, including anti-cancer effects. However, challenges concerning limited bioavailability, poor solubility, and potential toxicity must be addressed. Combining natural compounds with LDH inhibitors has led to promising outcomes in preclinical studies. This review highlights the promise of natural compounds as LDH inhibitors for treating cancer, cardiovascular, and neurodegenerative diseases.

Silymarin inhibits the progression of Ehrlich solid tumor via targeting molecular pathways of cell death, proliferation, angiogenesis, and metastasis in female mice

BACKGROUND

Plant-derived phytochemicals have been reported to exert anticancer activity. This study investigated the antitumor role of silymarin (Silybum marianum) (SMN) and its molecular targets in Ehrlich solid tumor xenografts in vivo.

METHODS AND RESULTS

Female Swiss albino mice were divided into three groups (of five animals each) that were engrafted with Ehrlich tumor (ET) cells with or without SMN treatment. The 3rd groups treated with DMSO only vehicle control group. A significant reduction in animal body mass and tumor volume/weight were observed in xenografted mice treated with SMN. SMN modulated oxidative stress in tumors while enhancing the antioxidant levels in mouse serum. SMN activated both mitochondrial and death receptor-related apoptosis pathways and induced cell cycle arrest, marked by a significant downregulation of cyclin D1 in SMN-treated tumors. Significant decreases in RNA content and protein expression levels of Ki-67 and proliferating cell nuclear antigen were observed in ET cells. Additionally, SMN downregulated vascular endothelial growth factor and nuclear factor-kappa B levels indicating anti-angiogenesis activity of this agent. SMN upregulated the expression of E-cadherin in tumor tissue suggesting, that SMN has potential ability to inhibit metastasis. Tumor tissue from SMN-treated animals showed a remarkable degeneration and reduction in the neoplastic cell density.

CONCLUSIONS

The anticancer effect was associated with apparent apoptosis in neoplastic cells with abundance of multifocal necrotic areas. SMN was found to inhibit ET growth via enhancing apoptosis, inhibition of cell division and reduction in angiogenesis in vivo. Hypothetical scheme of SMN antitumor effects (mechanism of signaling) in solid ET in vivo. SMN anticancer effect may be mediated by molecular mediators that affect proliferation, cell cycle activity, apoptotic pathways, angiogenesis, and metastasis.

Role of Silymarin in Cancer Treatment: Facts, Hypotheses, and Questions

The flavonoid silymarin extracted from the seeds of Sylibum marianum is a mixture of 6 flavolignan isomers. The 3 more important isomers are silybin (or silibinin), silydianin, and silychristin. Silybin is functionally the most active of these compounds. This group of flavonoids has been extensively studied and they have been used as hepato-protective substances for the mushroom Amanita phalloides intoxication and mainly chronic liver diseases such as alcoholic cirrhosis and nonalcoholic fatty liver. Hepatitis C progression is not, or slightly, modified by silymarin. Recently, it has also been proposed for SARS COVID-19 infection therapy. The biochemical and molecular mechanisms of action of these substances in cancer are subjects of ongoing research. Paradoxically, many of its identified actions such as antioxidant, promoter of ribosomal synthesis, and mitochondrial membrane stabilization, may seem protumoral at first sight, however, silymarin compounds have clear anticancer effects. Some of them are: decreasing migration through multiple targeting, decreasing hypoxia inducible factor-1α expression, inducing apoptosis in some malignant cells, and inhibiting promitotic signaling among others. Interestingly, the antitumoral activity of silymarin compounds is limited to malignant cells while the nonmalignant cells seem not to be affected. Furthermore, there is a long history of silymarin use in human diseases without toxicity after prolonged administration. The ample distribution and easy accessibility to milk thistle-the source of silymarin compounds, its over the counter availability, the fact that it is a weed, some controversial issues regarding bioavailability, and being a nutraceutical rather than a drug, has somehow led medical professionals to view its anticancer effects with skepticism. This is a fundamental reason why it never achieved bedside status in cancer treatment. However, in spite of all the antitumoral effects, silymarin actually has dual effects and in some cases such as pancreatic cancer it can promote stemness. This review deals with recent investigations to elucidate the molecular actions of this flavonoid in cancer, and to consider the possibility of repurposing it. Particular attention is dedicated to silymarin's dual role in cancer and to some controversies of its real effectiveness.

Transcriptome profiling reveals Silibinin dose-dependent response network in non-small lung cancer cells

Silibinin (SIL), a natural flavonolignan from the milk thistle (Silybum marianum), is known to exhibit remarkable hepatoprotective, antineoplastic and EMT inhibiting effects in different cancer cells by targeting multiple molecular targets and pathways. However, the predominant majority of previous studies investigated effects of this phytocompound in a one particular cell line. Here, we carry out a systematic analysis of dose-dependent viability response to SIL in five non-small cell lung cancer (NSCLC) lines that gradually differ with respect to their intrinsic EMT stage. By correlating gene expression profiles of NSCLC cell lines with the pattern of their SIL IC50 response, a group of cell cycle, survival and stress responsive genes, including some prominent targets of STAT3 (BIRC5, FOXM1, BRCA1), was identified. The relevancy of these computationally selected genes to SIL viability response of NSCLC cells was confirmed by the transient knockdown test. In contrast to other EMT-inhibiting compounds, no correlation between the SIL IC50 and the intrinsic EMT stage of NSCLC cells was observed. Our experimental results show that SIL viability response of differently constituted NSCLC cells is linked to a subnetwork of tightly interconnected genes whose transcriptomic pattern can be used as a benchmark for assessment of individual SIL sensitivity instead of the conventional EMT signature. Insights gained in this study pave the way for optimization of customized adjuvant therapy of malignancies using Silibinin.

Expression level of NEAT1 differentiates benign and malignant thyroid nodules by regulating NEAT1/miR‑9/PTEN and NEAT1/miR‑124/PDCD6 signalling

The incidence of thyroid nodules has been increasing worldwide; however, there are currently no feasible and robust methods to differentiate malignant thyroid nodules from benign thyroid nodules. The present study aimed to establish a practical method to determine the malignancy of thyroid nodules. Reverse transcription-quantitative PCR and western blot analyses were performed to compare the levels of long non-coding RNA nuclear enriched abundant transcript 1 (NEAT1), microRNA (miR)-9, miR-124, PTEN and programmed cell death protein 6 (PDCD6) in the peripheral blood and thyroid tissue samples between patients with malignant and benign thyroid nodules. Additionally, a regulatory relationship between NEAT1, miR-124, miR-9, PTEN and PDCD6 was established in the present study. The diagnostic value of NEAT1, miR-124 and miR-9 was determined using a ROC analysis. The expression levels of NEAT1, PTEN and PDCD6 in peripheral blood and thyroid tissue samples collected from the benign group were higher compared with those in the malignant group, whereas the expression levels of miR-124 and miR-9 were lower in the benign group. In the peripheral blood, NEAT1 expression exhibited an area under the curve (AUC) value of 0.8546, whereas miR-124 and miR-9 expression had AUC values of 0.7657 and 0.7019, respectively. In the thyroid tissue, NEAT1, miR-124, and miR-9 had AUC values of 0.9304, 0.8221 and 0.7757, respectively. Additionally, miR-9 and miR-124 expression levels in BCPaP and SW579 cells was decreased after transfection with a NEAT1 expression vector compared with those in cells transfected with the control vector, whereas the expression of PTEN and PDCD6 was upregulated. By contrast, transfection with short hairpin RNA targeting NEAT1 notably increased the expression of miR-9 and miR-124 while downregulating the expression of PTEN and PDCD6 compared with that in the control cells. In conclusion, the results of the present study demonstrated that the dysregulation of NEAT1 expression may be used to differentiate benign and malignant thyroid nodules.

Silymarin and Cancer: A Dual Strategy in Both in Chemoprevention and Chemosensitivity

Silymarin extracted from milk thistle consisting of flavonolignan silybin has shown chemopreventive and chemosensitizing activity against various cancers. The present review summarizes the current knowledge on the potential targets of silymarin against various cancers. Silymarin may play on the system of xenobiotics, metabolizing enzymes (phase I and phase II) to protect normal cells against various toxic molecules or to protect against deleterious effects of chemotherapeutic agents on normal cells. Furthermore, silymarin and its main bioactive compounds inhibit organic anion transporters (OAT) and ATP-binding cassettes (ABC) transporters, thus contributing to counteracting potential chemoresistance. Silymarin and its derivatives play a double role, namely, limiting the progression of cancer cells through different phases of the cycle-thus forcing them to evolve towards a process of cell death-and accumulating cancer cells in a phase of the cell cycle-thus making it possible to target a greater number of tumor cells with a specific anticancer agent. Silymarin exerts a chemopreventive effect by inducing intrinsic and extrinsic pathways and reactivating cell death pathways by modulation of the ratio of proapoptotic/antiapoptotic proteins and synergizing with agonists of death domains receptors. In summary, we highlight how silymarin may act as a chemopreventive agent and a chemosensitizer through multiple pathways.

Low-Frequency Magnetic Fields (LF-MFs) Inhibit Proliferation by Triggering Apoptosis and Altering Cell Cycle Distribution in Breast Cancer Cells

Breast cancer is a common malignancy threatening women’s health around the world. Despite improved treatments for different subtypes of breast tumors that have been put forward, there still exists a poor therapeutic response and prognosis. Magnetic fields, as a non-invasive therapy, have shown anti-tumor effects in vitro and in vivo; however, the detailed mechanisms involved are still not clear. In this study, we found that in exposure to low-frequency magnetic fields (LF-MFs) with an intensity of 1 mT and frequencies of 50, 125, 200, and 275 Hz, separately, the proliferation of breast cancer cells was inhibited and LF-MF with 200 Hz reached the optimum inhibition effect, on exposure time-dependently. Notably, we found that exposure to LF-MF led to MCF-7 and ZR-75-1 cell apoptosis and cell cycle arrest. Moreover, we also discovered that LF-MF effectively increased the level of reactive oxygen species (ROS), suppressed the PI3K/AKT signaling pathway, and activated glycogen synthase kinase-3β (GSK-3β). We demonstrated that the GSK3β activity contributed to LF-MF-induced cell proliferation inhibition and apoptosis, while the underlying mechanism was associated with the inhibition of PI3K/AKT through increasing the intracellular ROS accumulation. These results indicate that LF-MF with a specific frequency may be an attractive therapy to treat breast cancers.

Silymarin suppresses HepG2 hepatocarcinoma cell progression through downregulation of Slit-2/Robo-1 pathway

BACKGROUND

14 million people are diagnosed with new cancer and approximately 8 million people die from cancer every year. Hepatocellular carcinoma is the most common type of liver cancer and covers almost 5-6% of cancer deaths worldwide. Silybum marianum, a plant that contains silymarin, has been used traditionally in the treatment of liver diseases for centuries. The antioxidant, anti-inflammatory and anti-fibrotic anti-cancer properties of silymarin have been demonstrated in several studies in vivo and in vitro. The Slit/Robo signaling pathway plays a role in many processes such as neurogenesis, angiogenesis, cell proliferation, cell movement, cancer progression, cell invasion, migration and metastasis. In this study, we aimed to investigate the effects of silymarin on HepG2 Hepatocellular carcinoma cells on Slit-2/Robo-1 signaling pathway and CXCR-4 which plays a role in the metastasis process.

METHODS

HepG2 Hepatocellular carcinoma cells were used in the study. Different doses of silymarin's effect on HepG2 cells were observed by hematoxylin and eosin staining. Immunoblotting techniques were used to test the expression of Slit-2/Robo-1 and CXCR4 protein level. Immunocytochemistry was used to visualize the localization of Slit-2/Robo-1 and CXCR4 protein within the cells.

RESULTS

Silymarin caused apoptosis in HepG2 cells, decreased the level of CXCR-4 protein dose-dependently, and decreased the Slit-2/Robo-1 protein level at low doses and increased it at high doses.

CONCLUSIONS

Silymarin doses showed anti-carcinogenic, anti-metastatic and apoptotic effects in a dose-dependent manner on HepG2 cells through the Slit-2/Robo-1 pathway.

Silymarin inhibits Toll-like receptor 8 gene expression and apoptosis in Ramos cancer cell line

OBJECTIVE

Silymarin is a herbal extract containing flavonolignans, and it has inhibitory effects against the growth of different cancer cell lines by inducing apoptosis. Toll-like receptors are suggested as a novel and attractive target to treat cancer. The current study aimed at examining the mechanism of silymarin-induced apoptosis in Ramos cells and investigating its effects on TLR8 expression.

MATERIALS AND METHODS

The half maximal inhibitory concentration (IC₅₀) of silymarin in Ramos cells was determined via MTT viability test while the type of cell death was tested by annexin V/propidium iodide (PI) double staining method. The activity of caspase-3 and expression of TLR8 were measured in a time-dependent manner (in IC₅₀) by colorimetric assay and real-time polymerase chain reaction (RT-PCR), respectively.

RESULTS

The results of MTT showed that IC₅₀ of silymarin in Ramos cells was 100 μg/ml after 48 hr treatment (p<0.01). Flow cytometry by annexin V/PI, showed that silymarin induced early/late apoptosis in this cell line (p<0.05 to p<0.01). In addition, the caspase-3 colorimetric method showed that caspase-3 increased in the Ramos cell line after treatment (p<0.01). This treatment led to a reduction in TLR8 mRNA expression in a time-dependent manner (p<0.01).

CONCLUSION

The results indicated a new mechanism in the anticancer activity of Toll-like receptor (TLR) signaling after silymarin treatment in Ramos cancer cell line. This plant could be used to develop anticancer agents inhibiting TLRs.

In vitro and in vivo anti-cancer activity of silymarin on oral cancer

Silymarin, a standardized extract from milk thistle fruits has been found to exhibit anti-cancer effects against various cancers. Here, we explored the anti-cancer activity of silymarin and its molecular target in human oral cancer in vitro and in vivo. Silymarin dose-dependently inhibited the proliferation of HSC-4 oral cancer cells and promoted caspase-dependent apoptosis. A human apoptosis protein array kit showed that death receptor 5 may be involved in silymarin-induced apoptosis, which was also shown through western blotting, immunocytochemistry, and reverse transcription-polymerase chain reaction. Silymarin increased cleaved caspase-8 and truncated Bid, leading to accumulation of cytochrome c. In addition, silymarin activated death receptor 5/caspase-8 to induce apoptotic cell death in two other oral cancer cell lines (YD15 and Ca9.22). Silymarin also suppressed tumor growth and volume without any hepatic or renal toxicity in vivo. Taken together, these results provide in vitro and in vivo evidence supporting the anti-cancer effect of silymarin and death receptor 5, and caspase-8 may be essential players in silymarin-mediated apoptosis in oral cancer.

Enhanced miR-9 promotes laryngocarcinoma cell survival via down-regulating PTEN

MicroRNAs (miRNAs) play important roles in gene regulation during laryngocarcinoma. MiR-9 is a potential oncomiR, but its function in laryngocarcinoma is not known. The aim of this study is to investigate the roles of miR-9 in laryngocarcinoma. We found miR-9 expression was higher in laryngocarcinoma tissues compared with their normal controls, so did the laryngocarcinoma cells. Cellular function of miR-9 indicated that miR-9 restoration in laryngocarcinoma cells could promote cell proliferation and metastasis. Phosphatase and tensin homolog (PTEN) was predicted as a target gene of miR-9 and verified using luciferase reporter assay. PTEN expression was down-regulated in the laryngocarcinoma cells with miR-9 overexpression. We also found that miR-9 expression was negatively associated with PTEN expression in laryngocarcinoma tissues.

Antimutagenic, Antigenotoxic, and Anticytotoxic Activities of Silybum Marianum [L.] Gaertn Assessed by the Salmonella Mutagenicity Assay (Ames Test) and the Micronucleus Test in Mice Bone Marrow

Silymarin (SM), a standardized extract from Silybum marianum (L.) Gaertn., is composed mainly of flavonolignans, and silibinin (SB) is its major active constituent. The present study aimed to evaluate the antimutagenic activities of SM and SB using the Ames mutagenicity test in Salmonella Typhimurium, as well as their anticytotoxic and antigenotoxic activities using the mouse bone marrow micronucleus test. To assess antimutagenicity, Salmonella Typhimurium strains were treated with different concentrations of SM or SB and the appropriate positive control for each strain. To assess antigenotoxicity and anticytotoxicity, Swiss mice were treated with different concentrations of SM or SB and mitomycin C (MMC). The results showed that SM was not significantly effective in reducing the number of frameshift mutations in strain TA98, while SB demonstrated significant protection at higher doses (P < 0.05). Regarding strain TA 100, SM and SB significantly decreased mutagenicity (point mutations) (P < 0.05). The results of the antigenotoxic evaluation demonstrated that SM and SB significantly reduced the frequency of micronucleated polychromatic erythrocytes (MNPCE) (P < 0.05). The results also indicated that SM and SB significantly attenuated MMC-induced cytotoxicity (P < 0.05). Based on these results, both SM and SB presented antimutagenic, antigenotoxic, and anticytotoxic actions.

Increase in apoptosis by combination of metformin with silibinin in human colorectal cancer cells

AIM: To investigate the effect of metformin on silibinin-induced apoptosis in human colorectal cancer (COLO 205) cells.

METHODS: MTT assays were performed to quantify cell viability. Western blot assays were applied to identify the expression of signaling proteins.

RESULTS: The combined treatment of COLO 205 cells with metformin and silibinin decreased cell survival at a dose insufficient to influence the non-malignant cells [Human colonic epithelial cells (HCoEpiC)]. Silibinin and metformin increased phosphatase and tensin homolog and 5’-adenosine monophosphate-activated protein kinase expression in COLO 205 cells and inhibited the phosphorylation of mammol/Lalian target of rapamycin. This combined treatment resulted in an increase in the expression of activated caspase 3 and apoptosis inducing factor, indicating apoptosis.

CONCLUSION: The combined treatment of human colorectal cancer cells with silibinin and metformin may induce apoptosis at a dose that does not affect HCoEpiC. This finding reveals a potential therapeutic strategy for the treatment of colorectal cancer.

Silymarin inhibits the progression of fibrosis in the early stages of liver injury in CCl₄-treated rats

Liver fibrosis, a common condition occurring during the evolution of almost all chronic liver diseases, is the consequence of hepatocyte injury that leads to the activation of Kupffer cells and hepatic stellate cells (HSC). Silymarin (Si) is a herbal product widely used for its hepatoprotective potential. Our study aims to investigate the effects of two different doses of Silymarin on a CCl4-induced model of liver fibrosis with a focus on the early stages of liver injury. Fifty Wistar rats were randomly divided into five groups (n=10): control group (sunflower oil twice a week); CMC group (carboxymethyl cellulose five times a week, sunflower oil twice a week); CCl4 group (CCl4 in sunflower oil, by gavage, twice a week); CCl4+Si 50 group (CCl4 twice a week, Silymarin 50 mg/b.w. in CMC five times a week); and CCl4+Si 200 group (similar to the previous group, with Si 200 mg/b.w.). One month after the experiment began we explored hepato-cytolysis (aminotransferases and lactate dehydrogenase), oxidative stress, fibrosis (histological score, hyaluronic acid), markers of HSC activation (transforming growth factor β1 [TGF-β1], and α-smooth muscle actin [α-SMA] expression by western blot) and activation of Kupffer cells by immunohistochemistry. Our data showed that Si 50 mg/b.w. had the capacity of reducing oxidative stress, hepato-cytolysis, fibrosis, activation of Kupffer cells, and the expression of α-SMA and TGF-β1 with better results than Si 200 mg/b.w. Thus, the usual therapeutic dose of Silymarin, administered in the early stages of fibrotic changes is capable of inhibiting the fibrogenetic mechanism and the progression of initial liver fibrosis.

Modulatory effect of silymarin on inflammatory mediators in experimentally induced benign prostatic hyperplasia: emphasis on PTEN, HIF-1α, and NF-κB

The current study aimed to investigate the potential role of the anti-inflammatory effects of silymarin (SIL) in inhibiting experimentally induced benign prostatic hyperplasia (BPH) in rats. Rats were injected testosterone (3 mg/kg/day, subcutaneously (s.c.)) for 2 weeks. In the treatment group, SIL (50 mg/kg, per orally (p.o.)) was administered daily to rats concomitantly with testosterone. Rats were killed 72 h after the last testosterone injection. Then, prostate tissues were dissected out, weighed, and subjected to histological, immunohistochemical, and biochemical examinations. Rats treated with testosterone showed marked increase in prostate weight and prostate weight/body weight with histopathological picture of inflammation and hyperplasia as well as increased collagen deposition. Co-treatment with SIL significantly alleviated these pathological changes. Further, SIL attenuated testosterone-induced nuclear factor-kappa B (NF-κB), cyclooxygenase-II (COX-II), and inducible nitric oxide synthase (iNOS) upregulation, and blunted testosterone-mediated increase in nitric oxide level and messenger RNA (mRNA) expression of interleukin-6 (IL-6) and IL-8. Testosterone-induced downregulation of phosphatase and tensin homolog (PTEN) and upregulation of hypoxia-inducible factor 1α (HIF-1α) were alleviated by SIL. Our findings highlight the anti-inflammatory properties of SIL as a crucial mechanism of its preventive actions against experimental BPH. This can be attributed to, at least partly, attenuating the expression of NF-kB and the subsequent inflammatory cascade, ameliorating the expression of PTEN, and mitigating that of HIF-1α. These data warrant further investigations for the potential use of SIL in the management of BPH.

New Therapeutic Potentials of Milk Thistle (Silybum marianum)

Silymarin is a bioflavonoid complex extract derived from dry seeds of Milk thistle [( Silybum marianum(L.) Gaernt. (Fam. Asteraceae/Compositaceae)] whose hepatoprotective effect has clinically been proved. Low toxicity, favorable pharmacokinetics, powerful antioxidant, detoxifying, preventive, protective and regenerative effects and side effects similar to placebo make silymarin extremely attractive and safe for therapeutic use. The medicinal properties of silymarin and its main component silibinin have been studied in the treatment of Alzheimer's disease, Parkinson's disease, sepsis, burns, osteoporosis, diabetes, cholestasis and hypercholesterolemia. Owing to its apoptotic effect, without cytotoxic effects, silymarin possesses potential applications in the treatment of various cancers. Silymarin is being examined as a neuro-, nephro- and cardio-protective in the damage of different etiologies due to its strong antioxidant potentials. Furthermore, it has fetoprotective (against the influence of alcohol) and prolactin effects and is safe to be used during pregnancy and lactation. Finally, the cosmetics industry is examining the antioxidant and UV-protective effects of silymarin. Further clinical studies and scientific evidence that silymarin and silibinin are effective in the therapy of various pathologies are indispensable in order to confirm their different flavonolignan pharmacological effects.