Molecular mechanisms of luteolin-7-O-glucoside-induced growth inhibition on human liver cancer cells: G2/M cell cycle arrest and caspase-independent apoptotic signaling pathways

Lonicerae Japonicae Flos with the homology of medicine and food: a review of active ingredients, anticancer mechanisms, pharmacokinetics, quality control, toxicity and applications

Lonicerae Japonicae Flos (LJF, called Jinyinhua in China), comes from the dried flower buds or flowers to be opened of Lonicera japonica Thunb. in the Lonicera family. It has a long history of medicinal use and has a wide range of application prospects. As modern research advances, an increasing number of scientific experiments have demonstrated the anticancer potential of LJF. However, there is a notable absence of systematic reports detailing the anti-tumor effects of LJF. This review integrates the principles of Traditional Chinese Medicine (TCM) with contemporary pharmacological techniques, drawing upon literature from authoritative databases such as PubMed, CNKI, and WanFang to conduct a comprehensive study of LJF. Notably, a total of 507 compounds have been isolated and characterized from the plant to date, which include volatile oils, organic acids, flavonoids, iridoids, triterpenes and triterpenoid saponins. Pharmacological studies have demonstrated that LJF extract, along with components such as chlorogenic acid, luteolin, rutin, luteoloside, hyperoside and isochlorogenic acid, exhibits potential anticancer activities. Consequently, we have conducted a comprehensive review and summary of the mechanisms of action and clinical applications of these components. Furthermore, we have detailed the pharmacokinetics, quality control, and toxicity of LJF, while also discussing its prospective applications in the fields of biomedicine and preventive healthcare. It is hoped that these studies will provide valuable reference for the clinical research, development, and application of LJF.

Luteolin: A promising modulator of apoptosis and survival signaling in liver cancer

Due to the increasing incidence of cancer and the difficulties in determining the safety profile of existing therapeutic approaches, cancer research has recently become heavily involved in the search for new therapeutic approaches. The therapeutic significance of natural substances, especially flavonoids, against the onset and progression of cancer has been emphasized in traditional food-based medicine. Interestingly, the flavone luteolin possesses biological effects that have been linked to its anti-inflammatory, antioxidant, and anticancer effects. Luteolin interacts with several downstream chemicals and signaling pathways, including those involved in apoptosis, autophagy, cell cycle progression, and angiogenesis, to exert its anticancer effects on various cancerous cells. A complete understanding of both intrinsic and extrinsic apoptotic pathways, autophagy, and, most critically, the nanodelivery of luteolin in liver cancer is provided in the current review.

Liver cancer wars: plant-derived polyphenols strike back

Liver cancer currently represents the leading cause of cancer-related death worldwide. The majority of liver cancer arises in the context of chronic inflammation and cirrhosis. Surgery, radiation therapy, and chemotherapy have been the guideline-recommended treatment options for decades. Despite enormous advances in the field of liver cancer therapy, an effective cure is yet to be found. Plant-derived polyphenols constitute a large family of phytochemicals, with pleiotropic effects and little toxicity. They can drive cellular events and modify multiple signaling pathways which involves initiation, progression and metastasis of liver cancer and play an important role in contributing to anti-liver cancer drug development. The potential of plant-derived polyphenols for treating liver cancer has gained attention from research clinicians and pharmaceutical scientists worldwide in the last decades. This review overviews hepatic carcinogenesis and briefly discusses anti-liver cancer mechanisms associated with plant-derived polyphenols, specifically involving cell proliferation, apoptosis, autophagy, angiogenesis, oxidative stress, inflammation, and metastasis. We focus on plant-derived polyphenols with experiment-based chemopreventive and chemotherapeutic properties against liver cancer and generalize their basic molecular mechanisms of action. We also discuss potential opportunities and challenges in translating plant-derived polyphenols from preclinical success into clinical applications.

Phytochemicals as Potential Lead Molecules against Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most prevalent form of liver cancer, accounting for 85-90% of liver cancer cases and is a leading cause of cancer-related mortality worldwide. The major risk factors for HCC include hepatitis C and B viral infections, along with chronic liver diseases, such as cirrhosis, fibrosis, and non-alcoholic steatohepatitis associated with metabolic syndrome. Despite the advancements in modern medicine, there is a continuous rise in the annual global incidence rate of HCC, and it is estimated to reach >1 million cases by 2025. Emerging research in phytomedicine and chemotherapy has established the anti-cancer potential of phytochemicals, owing to their diverse biological activities. In this review, we report the major phytochemicals that have been explored in combating hepatocellular carcinoma and possess great potential to be used as an alternative or in conjunction with the existing HCC treatment modalities. An overview of the pre-clinical observations, mechanism of action and molecular targets of some of these phytochemicals is also incorporated.

An overview of structure-based activity outcomes of pyran derivatives against Alzheimer's disease

Pyran is a heterocyclic group containing oxygen that possesses a variety of pharmacological effects. Pyran is also one of the most prevalent structural subunits in natural products, such as xanthones, coumarins, flavonoids, benzopyrans, etc. Additionally demonstrating the neuroprotective properties of pyrans is the fact that this heterocycle has recently attracted the attention of scientists worldwide. Alzheimer's Disease (AD) treatment and diagnosis are two of the most critical research objectives worldwide. Increased amounts of extracellular senile plaques, intracellular neurofibrillary tangles, and a progressive shutdown of cholinergic basal forebrain neuron transmission are often related with cognitive impairment. This review highlights the various pyran scaffolds of natural and synthetic origin that are effective in the treatment of AD. For better understanding synthetic compounds are categorized as different types of pyran derivatives like chromene, flavone, xanthone, xanthene, etc. The discussion encompasses both the structure-activity correlations of these compounds as well as their activity against AD. Because of the intriguing actions that were uncovered by these pyran-based scaffolds, there is no question that they are at the forefront of the search for potential medication candidates that could treat Alzheimer's disease.

Modulation of Cell Death Pathways for Cellular Protection and Anti-Tumoral Activity: The Role of Thymus spp. Extracts and Their Bioactive Molecules

Natural products used for their health-promoting properties have accompanied the evolution of humanity. Nowadays, as an effort to scientifically validate the health-promoting effects described by traditional medicine, an ever-growing number of bioactivities are being described for natural products and the phytochemicals that constitute them. Among them, medicinal plants and more specifically the Thymus genus spp., arise as products already present in the diet and with high acceptance, that are a source of phytochemicals with high pharmacological value. Phenolic acids, flavonoid glycoside derivatives, and terpenoids from Thymus spp. have been described for their ability to modulate cell death and survival pathways, much-valued bioactivities in the pharmaceutical industry, that continually sought-after new formulations to prevent undesired cell death or to control cell proliferation. Among these, wound treatment, protection from endogenous/exogenous toxic molecules, or the induction of selective cell death, such as the search for new anti-tumoral agents, arise as main objectives. This review summarizes and discusses studies on Thymus spp., as well as on compounds present in their extracts, with regard to their health-promoting effects involving the modulation of cell death or survival signaling pathways. In addition, studies regarding the main bioactive molecules and their cellular molecular targets were also reviewed. Concerning cell survival and proliferation, Thymus spp. present themselves as an option for new formulations designed for wound healing and protection against chemicals-induced toxicity. However, Thymus spp. extracts and some of their compounds regulate cell death, presenting anti-tumoral activity. Therefore Thymus spp. is a rich source of compounds with nutraceutical and pharmaceutical value.

Anti-hepatitis B virus activity of food nutrients and potential mechanisms of action

Hepatitis B virus (HBV) is endemic in many parts of the world and is a significant cause of chronic liver damage and hepatocellular carcinoma. HBV therapeutics vary according to the disease stage. The best therapeutic option for patients with end-stage liver disease is liver transplantation, while for chronic patients, HBV infection is commonly managed using antivirals (nucleos(t)ides analogs or interferons). However, due to the accessibility issues and the high cost of antivirals, most HBV patients do not have access to treatment. These complications have led researchers to reconsider treatment approaches, such as nutritional therapy. This review summarizes the nutrients reported to have antiviral activity against HBV and their possible mechanism of action. Recent studies suggest resveratrol, vitamin E, lactoferrin, selenium, curcumin, luteolin-7-O-glucoside, moringa extracts, chlorogenic acid, and epigallocatechin-3-gallate may be beneficial for patients with hepatitis B. The anti-HBV effect of most of these nutrients has been analyzed in vitro and in animal models. Different antiviral and hepatoprotective mechanisms have been proposed for these nutrients, such as the activation of antioxidant and anti-inflammatory pathways, regulation of metabolic homeostasis, epigenetic control, activation of the p53 gene, inhibition of oncogenes, inhibition of virus entry, and induction of autophagosomes. In conclusion, scientific evidence indicates that HBV replication, transcription, and expression of viral antigens can be affected directly by nutrients. In the future, these nutrients may be considered to develop appropriate nutritional management for patients with hepatitis B.

Metabolomics analyses of traditional Chinese medicine formula Shuang Huang Lian by UHPLC-QTOF-MS/MS

Background

Shuang Huang Lian (SHL) is a traditional Chinese medicine (TCM) formula made from Lonicerae Japonicae Flos, Forsythiae Fructus, and Scutellariae Radix. Despite the widespread use of SHL in clinical practice for treating upper respiratory tract infections (URTIs), the complete component fingerprint and the pharmacologically active components in the SHL formula remain unclear. The objective of this study was to develop an untargeted metabolomics method for component identification, quantitation, pattern recognition, and cross-comparison of various SHL preparation forms (i.e., granule, oral liquid, and tablet).

Methods

Ultra-high-performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS) together with bioinformatics were used for chemical profiling, identification, and quantitation of SHL. Multivariate data analyses such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were performed to assess the correlations among the three SHL preparation forms and the reproducibility of the technical and biological replicates.

Results

A UHPLC-QTOF-MS/MS-based untargeted metabolomics method was developed and applied to analyze three SHL preparation forms, consisting of 178 to 216 molecular features. Among the 95 common molecular features from the three SHL preparation forms, quantitative analysis was performed using a single exogenous reference internal standard. Forty-seven of the 95 common molecular features have been identified using various databases. Among the 47 common components, there were 17 flavonoids, 7 oligopeptides, 5 terpenoids, 2 glycosides, 2 cyclohexanecarboxylic acids, 2 spiro compounds, 2 lipids, 2 glycosylglycerol derivatives, and 8 various compounds such as alkyl caffeate ester, aromatic ketone, benzaldehyde, benzodioxole, benzofuran, chalcone, hydroxycoumarin, and purine nucleoside. Five of the 47 common components were designated by the Chinese Pharmacopoeia as the quality markers of medicinal plants of SHL, and 15 were previously reported to have pharmacological activities. Distinct patterns of the three SHL preparation forms were observed in the PCA and PLS-DA plots.

Conclusions

The developed method is reliable and reproducible, which is useful for the profiling, component identification, quantitation, quality assessment of various SHL preparation forms and may apply to the analysis of other TCM formulas.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00610-x.

Cytotoxicity and 1H NMR metabolomics analyses of microalgal extracts for synergistic application with Tamoxifen on breast cancer cells with reduced toxicity against Vero cells

This study evaluated the cytotoxic activity of Tamoxifen (TMX), an anti-estrogen drug, with microalgal crude extracts (MCEs) in single and synergistic application (TMX-MCEs) on MCF-7 and 4T1 breast cancer cells, and non-cancerous Vero cells. The MCEs of Nannochloropsis oculata, Tetraselmis suecica and Chlorella sp. from five different solvents (methanol, MET; ethanol, ETH; water, W; chloroform, CHL; and hexane, HEX) were developed. The TMX-MCEs-ETH and W at the 1:2 and 1:3 ratios, attained IC50 of 15.84-29.51 μg/mL against MCF-7; 13.8-31.62 μg/mL against 4T1; and 24.54-85.11 μg/mL against Vero cells. Higher late apoptosis was exhibited against MCF-7 by the TMX-N. oculata-ETH (41.15 %); and by the TMX-T. suecica-ETH (65.69 %) against 4T1 cells. The TMX-T. suecica-ETH also showed higher ADP/ATP ratios, but comparable Caspase activities to control. For Vero cells, overall apoptotic effects were lowered with synergistic application, and only early apoptosis was higher with TMX-T. suecica-ETH but at lower levels (29.84 %). The MCEs-W showed the presence of alanine, oleic acid, linoleic acid, lactic acid, and fumaric acid. Based on Principal Component Analysis (PCA), the spectral signals for polar solvents such as MET and ETH, were found in the same cluster, while the non-polar solvent CHL was with HEX, suggesting similar chemical profiles clustered for the same polarity. The CHL and HEX were more effective with N. oculata and T. suecica which were of the marine origin, while the ETH and MET were more effective with Chlorella sp., which was of the freshwater origin. The synergistic application of microalgal bioactive compounds with TMX can maintain the cytotoxicity against breast cancer cells whilst reducing the toxicity against non-cancerous Vero cells. These findings will benefit the biopharmaceutical, and functional and healthy food industries.

Evaluation of Phytochemical Contents and In Vitro Antioxidant, Anti-Inflammatory, and Anticancer Activities of Black Rice Leaf (Oryza sativa L.) Extract and Its Fractions

Black rice leaves (Oryza sativa L.) are a major part of rice straw left in open fields after rice harvest as agricultural waste. In this study, crude ethanolic extract (CEE) and various solvent fractions (hexane (Hex), ethyl acetate (EtOAc), n-butanol (n-BuOH), and aqueous fractions) of black rice leaves were investigated for their bioactive compound contents as well as antioxidant, anti-inflammatory, and anticancer activities. The results demonstrated that among all the fractions, the n-BuOH fraction presented the greatest contents of total phenolics and flavonoids, while anthocyanins were found to be abundant in the n-BuOH and aqueous fractions, which also exhibited powerful antioxidant abilities according to DPPH and ABTS radical-scavenging assays and a reducing power assay. Regarding anti-inflammatory activity, CEE and EtOAc reduced the production of NO and cytokine secretion (PGE2, IL-6, and IL-1β) but displayed less effect on tumor necrosis factor α (TNF-α) release in lipopolysaccharide (LPS)-induced RAW 264.7 cells. They also significantly decreased iNOS and COX-2 protein expression. Additionally, the phenolics-rich ethyl acetate fraction showed the greatest activity against HepG2 liver carcinoma cells, inhibited cell growth, increased the Sub-G1 population, and induced apoptosis via mitochondrion-dependent mechanisms. In conclusion, black rice leaves, a byproduct of rice, exhibited strong antioxidant, anti-inflammatory, and anticancer capacities and might be useful for application in functional foods and the pharmaceutical industry.

Synthetic and Naturally Occurring Heterocyclic Anticancer Compounds with Multiple Biological Targets

Cancer is a complex group of diseases initiated by abnormal cell division with the potential of spreading to other parts of the body. The advancement in the discoveries of omics and bio- and cheminformatics has led to the identification of drugs inhibiting putative targets including vascular endothelial growth factor (VEGF) family receptors, fibroblast growth factors (FGF), platelet derived growth factors (PDGF), epidermal growth factor (EGF), thymidine phosphorylase (TP), and neuropeptide Y4 (NY4), amongst others. Drug resistance, systemic toxicity, and drug ineffectiveness for various cancer chemo-treatments are widespread. Due to this, efficient therapeutic agents targeting two or more of the putative targets in different cancer cells are proposed as cutting edge treatments. Heterocyclic compounds, both synthetic and natural products, have, however, contributed immensely to chemotherapeutics for treatments of various diseases, but little is known about such compounds and their multimodal anticancer properties. A compendium of heterocyclic synthetic and natural product multitarget anticancer compounds, their IC50, and biological targets of inhibition are therefore presented in this review.

Anti-Hepatocellular Carcinoma Biomolecules: Molecular Targets Insights

This report explores the available curative molecules directed against hepatocellular carcinoma (HCC). Limited efficiency as well as other drawbacks of existing molecules led to the search for promising potential alternatives. Understanding of the cell signaling mechanisms propelling carcinogenesis and driven by cell proliferation, invasion, and angiogenesis can offer valuable information for the investigation of efficient treatment strategies. The complexity of the mechanisms behind carcinogenesis inspires researchers to explore the ability of various biomolecules to target specific pathways. Natural components occurring mainly in food and medicinal plants, are considered an essential resource for discovering new and promising therapeutic molecules. Novel biomolecules normally have an advantage in terms of biosafety. They are also widely diverse and often possess potent antioxidant, anti-inflammatory, and anti-cancer properties. Based on quantitative structure-activity relationship studies, biomolecules can be used as templates for chemical modifications that improve efficiency, safety, and bioavailability. In this review, we focus on anti-HCC biomolecules that have their molecular targets partially or completely characterized as well as having anti-cancer molecular mechanisms that are fairly described.

Luteolin-7-O-glucoside inhibits cell proliferation and modulates apoptosis through the AKT signaling pathway in human nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an unnoticeable malignant tumor with a high potential of lymphatic metastasis, and its prevalence is high in Asia. Ionizing radiation is the mainstay of treatment for patients with NPC without metastasis. However, patients with metastatic lesions require advanced treatments such as chemotherapy. The present study investigated the apoptotic effect of luteolin-7-O-glucoside on NPC cells and elucidated its underlying signaling mechanisms. The results revealed that luteolin-7-O-glucoside significantly reduced the proliferation of NPC cell lines (NPC-039 and NPC-BM). Flow cytometry and morphological analysis results demonstrated that luteolin-7-O-glucoside treatment induced S and G₂ /M cell cycle arrest, chromatin condensation, and apoptosis. In addition, mitochondrial membrane potential was observed to be depolarized with an increasing concentration of luteolin-7-O-glucoside. Proteins involved in the extrinsic and intrinsic pathways of apoptosis, such as death receptor, caspase-3, caspase-8, caspase-9, and Bcl-2 family proteins (Bax, t-Bid, Bcl-2, and Bcl-xL), were downregulated and upregulated after treatment with luteolin-7-O-glucoside, respectively. Moreover, the addition of a PI3K/AKT inhibitor enhanced the activation of poly-ADP-ribose-polymerase (PARP) and attenuated cell viability, indicating that luteolin-7-O-glucoside induced apoptosis in NPC cells through the AKT signaling pathway. These results indicated that the apoptosis of NPC cells modulated by luteolin-7-O-glucoside may be preceded by mitochondrial depolarization, cell cycle arrest, extrinsic and intrinsic apoptosis pathway activation, and AKT signaling modulation. Thus, luteolin-7-O-glucoside can be a promising anticancer agent against human NPC.

Hydromethanolic root and aerial part extracts from Echium arenarium Guss suppress proliferation and induce apoptosis of multiple myeloma cells through mitochondrial pathway

Echium arenarium Guss is a Mediterranean plant traditionally used in healing skin wound and it was reported exhibiting potent antioxidant, antibacterial, and antiparasitic activities. However, antitumoral activities of this plant have not yet been explored. Here we investigated for the first time, root (EARE) and aerial part (EAAPE) extracts of E. arenarium Guss to examine cytotoxicity and apoptosis activation pathway on U266 human multiple myeloma (MM) cell line. We demonstrated that EARE and EAAPE decreased U266 cell viability in a dose dependent manner. Based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, EARE was significantly two times more efficient (IC50 value 41 μg/ml) than EAAPE (IC50 value 82 μg/ml) considering 48 h of treatment. Furthermore, after 24 h of exposure to 100 μg/ml of EARE or EAAPE, cell cycle showed remarkable increase in sub-G1 population and a decrease of U266 cells proportion in G1 phase. In addition, EARE increased cell percentage in S phase. Moreover, analysis revealed that EAAPE or EARE induced apoptosis of U266 cells after 24 h of treatment. Interestingly, depolarization of mitochondrial membrane potential and activation of caspase 3/7 were demonstrated in treated U266 cells. Phytochemical analysis of E. arenarium extracts showed that EARE exhibited the highest content of total phenolic content. Interestingly, six phenolic compounds were identified. Myricitrin was the major compound in EARE, followed by luteolin 7-O-glucoside, resorcinol, polydatin, Trans-hydroxycinnamic acid, and hyperoside. These findings proved that an intrinsic mitochondria-mediated apoptosis pathway probably mediated the apoptotic effects of E. arenarium Guss extracts on U266 cells, and this will suggest several action plans to treat MM.

Luteolin-7-O-Glucoside Inhibits Oral Cancer Cell Migration and Invasion by Regulating Matrix Metalloproteinase-2 Expression and Extracellular Signal-Regulated Kinase Pathway

Oral squamous cell carcinoma is the sixth most common type of cancer globally, which is associated with high rates of cancer-related deaths. Metastasis to distant organs is the main reason behind worst prognostic outcome of oral cancer. In the present study, we aimed at evaluating the effects of a natural plant flavonoid, luteolin-7-O-glucoside, on oral cancer cell migration and invasion. The study findings showed that in addition to preventing cell proliferation, luteolin-7-O-glucoside caused a significant reduction in oral cancer cell migration and invasion. Mechanistically, luteolin-7-O-glucoside caused a reduction in cancer metastasis by reducing p38 phosphorylation and downregulating matrix metalloproteinase (MMP)-2 expression. Using a p38 inhibitor, SB203580, we proved that luteolin-7-O-glucoside exerts anti-migratory effects by suppressing p38-mediated increased expression of MMP-2. This is the first study to demonstrate the luteolin-7-O-glucoside inhibits cell migration and invasion by regulating MMP-2 expression and extracellular signal-regulated kinase pathway in human oral cancer cell. The study identifies luteolin-7-O-glucoside as a potential anti-cancer candidate that can be utilized clinically for improving oral cancer prognosis.

ZNF488 is an independent prognostic indicator in nasopharyngeal carcinoma and promotes cell adhesion and proliferation via collagen IV/FAK/AKT/Cyclin D1 pathway

Background: ZNF488 acts as an oncogene which promotes cell invasion and endows tumor cells stem cell capacity in nasopharyngeal carcinoma (NPC), but its correlation with clinicopathologic characteristics and patients' survival in NPC remain undefined. Methods: In this study, 158 cases of confirmed NPC were subjected to immunohistochemistry staining for evaluating endogenous expression. Kaplan-Meier method and log-rank test were used to estimate the survival rates. The relationship between ZNF488 and clinicopathological characteristics was statistically calculated by chi-squared test, univariate and multivariate analysis. In addition, adhesion assay, MTT and colony formation assays were performed for measuring adhesion and proliferation capacity. Cell cycle analysis via flow cytometry was conducted to explore cell cycle distribution. Western blot was used to detect pathway protein levels, and the pFAK (Y397) kit was used for focal adhesion kinase (FAK) activation. Results: We demonstrated that high expression of ZNF488 was significantly correlated with locoregional failure (P=0.018) and distant metastasis (P=0.001). Patients with high ZNF488 expression had poorer overall survival (P<0.001), loco-regional recurrence-free survival (P<0.001), distance metastasis-free survival (P<0.001) and progression-free survival (P<0.001) than those with low ZNF488 group. Multivariate analysis showed that ZNF488 expression was an independent prognostic indicator for predicting NPC patients' survival (HR, 3.314; 95% CI, 1.489-7.386; P=0.003). Additionally, ZNF488-induced collagen IV/FAK/AKT to enhance adhesion ability meanwhile led to the upregulation of Cyclin D1 to facilitate cell proliferation through promoting cell cycle progression and inhibition of apoptosis through caspase-independent way. Conclusion: These results reveal that ZNF488, as an independent prognostic indicator, promotes cell adhesion and proliferation through collagen IV/FAK/AKT/Cyclin D1 pathway in NPC.

HIF-1α/VEGF signaling-mediated epithelial-mesenchymal transition and angiogenesis is critically involved in anti-metastasis effect of luteolin in melanoma cells

Tumor metastasis is still the leading cause of melanoma mortality. Luteolin, a natural flavonoid, is found in fruits, vegetables, and medicinal herbs. The pharmacological action and mechanism of luteolin on the metastasis of melanoma remain elusive. In this study, we investigated the effect of luteolin on A375 and B16‐F10 cell viability, migration, invasion, adhesion, and tube formation of human umbilical vein endothelial cells. Epithelial–mesenchymal transition (EMT) markers and pivotal molecules in HIF‐1α/VEGF signaling expression were analysed using western blot assays or quantitative real‐time polymerase chain reaction. Results showed that luteolin inhibits cellular proliferation in A375 and B16‐F10 melanoma cells in a time‐dependent and concentration‐dependent manner. Luteolin significantly inhibited the migratory, invasive, adhesive, and tube‐forming potential of highly metastatic A375 and B16‐F10 melanoma cells or human umbilical vein endothelial cells at sub‐IC₅₀ concentrations, where no significant cytotoxicity was observed. Luteolin effectively suppressed EMT by increased E‐cadherin and decreased N‐cadherin and vimentin expression both in mRNA and protein levels. Further, luteolin exerted its anti‐metastasis activity through decreasing the p‐Akt, HIF‐1α, VEGF‐A, p‐VEGFR‐2, MMP‐2, and MMP‐9 proteins expression. Overall, our findings first time suggests that HIF‐1α/VEGF signaling‐mediated EMT and angiogenesis is critically involved in anti‐metastasis effect of luteolin as a potential therapeutic candidate for melanoma.

Luteoloside Inhibits Proliferation and Promotes Intrinsic and Extrinsic Pathway-Mediated Apoptosis Involving MAPK and mTOR Signaling Pathways in Human Cervical Cancer Cells

Cervical cancer is a common gynecological malignancy with high incidence and mortality. Drugs commonly used in chemotherapy are often accompanied by strong side-effects. To find an anti-cervical cancer drug with high effects and low toxicity, luteoloside was used to treat the cervical cancer cell line Hela to investigate its effects on cell morphology, proliferation, apoptosis, and related proteins. The study demonstrated that luteoloside could inhibit proliferation remarkably; promote apoptosis and cytochrome C release; decrease the mitochondrial membrane potential and reactive oxygen species level; upregulate the expression of Fas, Bax, p53, phospho-p38, phospho-JNK, and cleaved PARP; downregulate the expression of Bcl-2 and phospho-mTOR; activate caspase-3 and caspase-8; change the nuclear morphology, and fragmentate DNA in Hela cells. These results strongly suggest that luteoloside can significantly inhibit the proliferation and trigger apoptosis in Hela cells. In contrast, luteoloside had less proliferation inhibiting effects on the normal cell lines HUVEC12 and LO2, and minor apoptosis promoting effects on HUVEC12 cells. Furthermore, the luteoloside-induced apoptosis in Hela cells is mediated by both intrinsic and extrinsic pathways and the effects of luteoloside may be regulated by the mitogen-activated protein kinases and mTOR signaling pathways via p53.

Natural product for the treatment of Alzheimer's disease

Alzheimer's disease (AD) is related to increasing age. It is mainly characterized by progressive neurodegenerative disease, which damages memory and cognitive function. Natural products offer many options to reduce the progress and symptoms of many kinds of diseases, including AD. Meanwhile, natural compound structures, including lignans, flavonoids, tannins, polyphenols, triterpenes, sterols, and alkaloids, have anti-inflammatory, antioxidant, anti-amyloidogenic, and anticholinesterase activities. In this review, we summarize the pathogenesis and targets for treatment of AD. We also present several medicinal plants and isolated compounds that are used for preventing and reducing symptoms of AD.

Beneficial Effects of Cynaroside on Cisplatin-Induced Kidney Injury In Vitro and In Vivo

Anti-cancer drugs such as cisplatin and doxorubicin are effectively used more than radiotherapy. Cisplatin is a chemotherapeutic drug, used for treatment of various forms of cancer. However, it has side effects such as ototoxicity and nephrotoxicity. Cisplatin-induced nephrotoxicity increases tubular damage and renal dysfunction. Consequently, we investigated the beneficial effect of cynaroside on cisplatin-induced kidney injury using HK-2 cell (human proximal tubule cell line) and an animal model. Results indicated that 10 μM cynaroside diminished cisplatin-induced apoptosis, mitochondrial dysfunction and caspase-3 activation, cisplatin-induced upregulation of caspase-3/MST-1 pathway decreased by treatment of cynaroside in HK-2 cells. To confirm the effect of cynaroside on cisplatin-induced kidney injury in vivo, we used cisplatin exposure animal model (20 mg/kg, balb/c mice, i.p., once a day for 3 days). Renal dysfunction, tubular damage and neutrophilia induced by cisplatin injection were decreased by cynaroside (10 mg/kg, i.p., once a day for 3 days). Results indicated that cynaroside decreased cisplatin-induced kidney injury in vitro and in vivo, and it could be used for improving cisplatin-induced side effects. However, further experiments are required regarding toxicity by high dose cynaroside and caspase-3/MST-1-linked signal transduction in the animal model.

Luteoloside attenuates anoxia/reoxygenation-induced cardiomyocytes injury via mitochondrial pathway mediated by 14-3-3η protein

Ischemia/reperfusion (I/R) injury is the major cause of acute cardiovascular disease worldwide. 14-3-3η protein has been demonstrated to protect myocardium against I/R injury. Luteoloside (Lut), a flavonoid found in many Chinese herbs, exerts myocardial protection effects. However, the mechanism remains unclear. We hypothesize that the cardioprotective role of Lut is exerted by regulating the 14-3-3η signal pathway. To investigate our hypothesis, an in vitro I/R model was generated in H9C2 cardiomyocytes by anoxia/reoxygenation (A/R) treatment. The effects of Lut on cardiomyocytes with A/R injury were assessed by determining the cell viability, lactate dehydrogenase levels, intracellular reactive oxygen species levels, mitochondrial permeability transition pores (mPTP) openness, caspase-3 activity, and apoptosis rate. The effects on protein expression were tested using western blot analysis. Lut attenuated A/R-induced injury to cardiomyocytes by increasing the expression of 14-3-3η protein and cell viability; decreasing levels of lactate dehydrogenase, reactive oxygen species, mPTP openness, caspase-3 activity, and low apoptosis rate were observed. However, the cardioprotective effects of Lut were blocked by AD14-3-3ηRNAi, an adenovirus knocking down the intracellular 14-3-3η expression. In conclusion, to our knowledge, this is the first study to demonstrate that Lut protected cardiomyocytes from A/R-induced injury via the regulation of 14-3-3η signaling pathway.

The Potential and Action Mechanism of Polyphenols in the Treatment of Liver Diseases

Liver disease, involving a wide range of liver pathologies from fatty liver, hepatitis, and fibrosis to cirrhosis and hepatocellular carcinoma, is a serious health problem worldwide. In recent years, many natural foods and herbs with abundant phytochemicals have been proposed as health supplementation for patients with hepatic disorders. As an important category of phytochemicals, natural polyphenols have attracted increasing attention as potential agents for the prevention and treatment of liver diseases. The striking capacities in remitting oxidative stress, lipid metabolism, insulin resistance, and inflammation put polyphenols in the spotlight for the therapies of liver diseases. It has been reported that many polyphenols from a wide range of foods and herbs exert therapeutic effects on liver injuries via complicated mechanisms. Therefore, it is necessary to have a systematical review to sort out current researches to help better understand the potentials of polyphenols in liver diseases. In this review, we aim to summarize and update the existing evidence of natural polyphenols in the treatment of various liver diseases by in vitro, in vivo, and clinical studies, while special attention is paid to the action mechanisms.

Novel in vitro and in silico insights of the multi-biological activities and chemical composition of Bidens tripartita L

Bidens tripartita L. is a traditional phyto-remedy used in several countries, yet there is still a paucity of data on its biological potential. We aimed to provide new insights on the pharmacological potential of extracts prepared from B. tripartita via highlighting its antioxidant, key enzymes inhibitory potency, and DNA protecting effects. Phytochemical profile was established using High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) and bioactive compound(s) docked against target enzymes using in silico methods. Cytotoxicity against three cancer cell lines was assessed using the methylthiazolyldiphenyl-tetrazolium bromide (MTT) cell viability test. The main compounds were luteolin-7-glucoside (cynaroside), chlorogenic acid, and epicatechin in the extracts. The methanol extract exhibited the highest radical scavenging activity. Ethyl acetate extract showed strongest α-amylase inhibitory activity, while the best α-glucosidase inhibitory effect recorded for the methanol extract. Molecular docking showed that cynaroside strongly interact to α-glucosidase cavity by establishing six hydrogen bonds. B. tripartita extracts were found to protect supercoiled form of pUC19 plasmid (>70%) and also showed anti-proliferative properties. Results amassed in the present study add on to a growing body of literature on the multi-pharmacological potency of B. tripartita which can be applied to bio-products development geared towards management of common diseases.

Phloridzin docosahexaenoate, a novel flavonoid derivative, suppresses growth and induces apoptosis in T-cell acute lymphoblastic leukemia cells

The overall clinical outcome in T-cell acute lymphoblastic leukemia (T-ALL) can be improved by minimizing risk for treatment failure using effective pharmacological adjuvants. Phloridzin (PZ), a flavonoid precursor found in apple peels, was acylated with docosahexaenoic acid (DHA) yielding a novel ester known as phloridzin docosahexaenoate (PZ-DHA). Here, we have studied the cytotoxic effects of PZ-DHA on human leukemia cells using in vitro and in vivo models. The inhibitory effects of PZ-DHA were tested on human Jurkat T-ALL cells in comparison to K562 chronic myeloid leukemia (CML) cells and non-malignant murine T-cells. PZ-DHA, not PZ or DHA alone, reduced cell viability and ATP levels, increased intracellular LDH release, and caused extensive morphological alterations in both Jurkat and K562 cells. PZ-DHA also inhibited cell proliferation, and selectively induced apoptosis in Jurkat and K562 cells while sparing normal murine T-cells. The cytotoxic effects of PZ-DHA on Jurkat cells were associated with caspase activation, DNA fragmentation, and selective down-regulation of STAT3 phosphorylation. PZ-DHA significantly inhibited Jurkat cell proliferation in zebrafish larvae; however, the proliferation of K562 cells was not affected in vivo. We propose that PZ-DHA-induced cytotoxic response is selective towards T-ALL in the presence of a tumor-stromal microenvironment. Prospective studies evaluating the combinatorial effects of PZ-DHA with conventional chemotherapy for T-ALL are underway.

Akt attenuates apoptotic death through phosphorylation of H2A under hydrogen peroxide-induced oxidative stress in PC12 cells and hippocampal neurons

Although the essential role of protein kinase B (PKB)/Akt in cell survival signaling has been clearly established, the mechanism by which Akt mediates the cellular response to hydrogen peroxide (H₂O₂)-induced oxidative stress remains unclear. We demonstrated that Akt attenuated neuronal apoptosis through direct association with histone 2A (H2A) and phosphorylation of H2A at threonine 17. At early time points during H₂O₂ exposure of PC12 cells and primary hippocampal neurons, when the cells can tolerate the level of DNA damage, Akt was activated and phosphorylated H2A, leading to inhibition of apoptotic death. At later time points, Akt delivered the NAD⁺-dependent protein deacetylase Sirtuin 2 (Sirt 2) to the vicinity of phosphorylated H2A in response to irreversible DNA damage, thereby inducing H2A deacetylation and subsequently leading to apoptotic death. Ectopically expressed T17A-substituted H2A minimally interacted with Akt and failed to prevent apoptosis under oxidative stress. Thus Akt-mediated H2A phosphorylation has an anti-apoptotic function in conditions of H₂O₂-induced oxidative stress in neurons and PC12 cells.

Protective Effects of Processed Ginseng and Its Active Ginsenosides on Cisplatin-Induced Nephrotoxicity: In Vitro and in Vivo Studies

Although cisplatin can dramatically improve the survival rate in cancer patients, its use is limited by its nephrotoxicity. Previous investigations showed that Panax ginseng contains components that exhibit protective activity against cisplatin-induced nephropathy. The aim of the present study is to investigate the effect of microwave-assisted processing on the protective effect of ginseng and identify ginsenosides that are active against cisplatin-induced kidney damage to evaluate the potential of using ginseng in the management of nephrotoxicity. The LLC-PK1 cell damage by cisplatin was significantly decreased by treatment with microwave-processed ginseng (MG) and ginsenosides Rg3, Rg5, and Rk1. Reduced expression of p53 and c-Jun N-terminal kinase proteins by cisplatin in LLC-PK1 cells was markedly ameliorated after Rg3 and Rg5/Rk1 treatment. Additionally, elevated expression of cleaved caspase-3 was significantly reduced by ginsenosides Rg5, Rk1, and with even greater potency, Rg3. Moreover, MG and its fraction containing active ginsenosides showed protective effects against cisplatin-induced nephropathy in mice. We found that ginsenosides Rg3, Rg5, and Rk1 generated during the heat treatment of ginseng ameliorate renal damage by regulating inflammation and apoptosis. Results of current experiments provide evidence of the renoprotective effects and therapeutic potential of MG and its active ginsenosides, both in vitro and in vivo.

Stigmasterol isolated from marine microalgae Navicula incerta induces apoptosis in human hepatoma HepG2 cells

Plant sterols have shown potent anti-proliferative effects and apoptosis induction against breast and prostate cancers. However, the effect of sterols against hepatic cancer has not been investigated. In the present study, we assessed whether the stigmasterol isolated from Navicula incerta possesses apoptosis inductive effect in hepatocarcimona (HepG2) cells. According to the results, Stigmasterol has up-regulated the expression of pro-apoptotic gene expressions (Bax, p53) while down-regulating the anti-apoptotic genes (Bcl-2). Probably via mitochondrial apoptosis signaling pathway. With the induction of apoptosis caspase-8, 9 were activated. The DNA damage and increase in apoptotic cell numbers were observed through Hoechst staining, annexin V staining and cell cycle analysis. According to these results, we can suggest that the stigmasterol shows potent apoptosis inductive effects and has the potential to be tested as an anti-cancer therapeutic against liver cancer. [BMB Reports 2014; 47(8): 433-438]

Novel TRAIL sensitizer Taraxacum officinale F.H. Wigg enhances TRAIL-induced apoptosis in Huh7 cells

TRAIL (TNF-related apoptosis inducing ligand) is a promising anti-cancer drug target that selectively induces apoptosis in cancer cells. However, many cancer cells are resistant to TRAIL-induced apoptosis. Therefore, reversing TRAIL resistance is an important step for the development of effective TRAIL-based anti-cancer therapies. We previously reported that knockdown of the TOR signaling pathway regulator-like (TIPRL) protein caused TRAIL-induced apoptosis by activation of the MKK7-c-Jun N-terminal Kinase (JNK) pathway through disruption of the MKK7-TIPRL interaction. Here, we identified Taraxacum officinale F.H. Wigg (TO) as a novel TRAIL sensitizer from a set of 500 natural products using an ELISA system and validated its activity by GST pull-down analysis. Furthermore, combination treatment of Huh7 cells with TRAIL and TO resulted in TRAIL-induced apoptosis mediated through inhibition of the MKK7-TIPRL interaction and subsequent activation of MKK7-JNK phosphorylation. Interestingly, HPLC analysis identified chicoric acid as a major component of the TO extract, and combination treatment with chicoric acid and TRAIL induced TRAIL-induced cell apoptosis via JNK activation due to inhibition of the MKK7-TIPRL interaction. Our results suggest that TO plays an important role in TRAIL-induced apoptosis, and further functional studies are warranted to confirm the importance of TO as a novel TRAIL sensitizer for cancer therapy. © 2015 Wiley Periodicals, Inc.

Antigenotoxic and antioxidant effects of the Mongolian medicinal plant Leptopyrum fumarioides (L): an in vitro study

ETHNOPHARMACOLOGICAL RELEVANCE

Leptopyrum fumarioides has been used in the traditional medicine of Mongolia for the treatment of various diseases, including drug intoxications. However, since there is only sparse information about its chemistry, active components, and pharmacological and toxicological effects, the major aim of the present study employing mouse lymphoma cells was to evaluate the genotoxic and antigenotoxic/antioxidative effects of extracts and components isolated from this plant.

MATERIAL AND METHODS

A crude methanol extract was separated into three different sub-extracts: dichloromethane, n-butanol, and water. The major constituent of the n-butanol extract, i.e., the flavone luteolin-7-O-glucoside and a mixture of the most abundant compounds in the dichloromethane sub-extract were then isolated. DNA damage was evaluated using the comet assay; the antioxidant activity was evaluated using the DPPH radical scavenging assay.

RESULTS

The crude methanol extract, the dichloromethane sub-extract and the mixture of compounds isolated from the latter fraction, increased the level of DNA damage after three hours of exposure. In contrast, no increase in DNA damage was observed in the cells that had been exposed to the n-butanol and water sub-extracts, or to the pure flavone. When non-DNA damaging concentrations of extracts and compounds were tested together with the DNA damaging agent catechol, all sub-extracts were found to reduce the catechol-induced DNA damage (the flavone was then found to be the most effective protective agent). The n-butanol sub-extract and the flavone were also found to have the most prominent antioxidative effects.

CONCLUSION

Based on the results from the present study, components in Leptopyrum fumarioides were found to protect the DNA damage induced by catechol, probably by acting as potent antioxidants.

β-lapachone-Induced Apoptosis of Human Gastric Carcinoma AGS Cells Is Caspase-Dependent and Regulated by the PI3K/Akt Pathway

β-lapachone is a naturally occurring quinone that selectively induces apoptotic cell death in a variety of human cancer cells in vitro and in vivo; however, its mechanism of action needs to be further elaborated. In this study, we investigated the effects of β-lapachone on the induction of apoptosis in human gastric carcinoma AGS cells. β-lapachone significantly inhibited cellular proliferation, and some typical apoptotic characteristics such as chromatin condensation and an increase in the population of sub-G1 hypodiploid cells were observed in β-lapachone-treated AGS cells. Treatment with β-lapachone caused mitochondrial transmembrane potential dissipation, stimulated the mitochondria-mediated intrinsic apoptotic pathway, as indicated by caspase-9 activation, cytochrome c release, Bcl-2 downregulation and Bax upregulation, as well as death receptor-mediated extrinsic apoptotic pathway, as indicated by activation of caspase-8 and truncation of Bid. This process was accompanied by activation of caspase-3 and concomitant with cleavage of poly(ADP-ribose) polymerase. The general caspase inhibitor, z-VAD-fmk, significantly abolished β-lapachone-induced cell death and inhibited growth. Further analysis demonstrated that the induction of apoptosis by β-lapachone was accompanied by inactivation of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. The PI3K inhibitor LY29004 significantly increased β-lapachone-induced apoptosis and growth inhibition. Taken together, these findings indicate that the apoptotic activity of β-lapachone is probably regulated by a caspase-dependent cascade through activation of both intrinsic and extrinsic signaling pathways, and that inhibition of the PI3K/Akt signaling may contribute to β-lapachone-mediated AGS cell growth inhibition and apoptosis induction.