Dioscin, a natural steroid saponin, induces apoptosis and DNA damage through reactive oxygen species: a potential new drug for treatment of glioblastoma multiforme

Dioscin decreases M2 polarization via inhibiting a positive feedback loop between RBM47 and NF-κB in glioma

BACKGROUND

The role of the glioblastoma (GBM) microenvironment is pivotal in the development of gliomas. Discovering drugs that can traverse the blood-brain barrier and modulate the tumor microenvironment is crucial for the treatment of GBM. Dioscin, a steroidal saponin derived from various kinds of plants and herbs known to penetrate the blood-brain barrier, has shown its powerful anti-tumor activity. However, little is known about its effects on GBM microenvironment.

METHODS

Bioinformatics analysis was conducted to assess the link between GBM patients and their prognosis. Multiple techniques, including RNA sequencing, immunofluorescence staining, Western blot analysis, RNA-immunoprecipitation (RIP) assays, and Chromatin immunoprecipitation (CHIP) analysis were employed to elucidate the mechanism through which Dioscin modulates the immune microenvironment.

RESULTS

Dioscin significantly impaired the polarization of macrophages into the M2 phenotype and enhanced the phagocytic ability of macrophages in vitro and in vivo. A strong correlation between high expression of RBM47 in GBM and a detrimental prognosis for patients was demonstrated. RNA-sequencing analysis revealed an association between RBM47 and the immune response. The inhibition of RBM47 significantly impaired the recruitment and polarization of macrophages into the M2 phenotype and enhanced the phagocytic ability of macrophages. Moreover, RBM47 could stabilize the mRNA of inflammatory genes and enhance the expression of these genes by activating the NF-κB pathway. In addition, NF-κB acts as a transcription factor that enhances the transcriptional activity of RBM47. Notably, we found that Dioscin could significantly inhibit the activation of NF-κB and then downregulate the expression of RBM47 and inflammatory genes protein.

CONCLUSION

Our study reveals that the positive feedback loop between RBM47 and NF-κB could promote immunosuppressive microenvironment in GBM. Dioscin effectively inhibits M2 polarization in GBM by disrupting the positive feedback loop between RBM47 and NF-κB, indicating its potential therapeutic effects in GBM treatment.

A review of natural products and small-molecule therapeutics acting on central nervous system malignancies: Approaches for drug development, targeting pathways, clinical trials, and challenges

In 2021, the World Health Organization released the fifth edition of the central nervous system (CNS) tumor classification. This classification uses histopathology and molecular pathogenesis to group tumors into more biologically and molecularly defined entities. The prognosis of brain cancer, particularly malignant tumors, has remained poor worldwide, approximately 308,102 new cases of brain and other CNS tumors were diagnosed in the year 2020, with an estimated 251,329 deaths. The cost and time-consuming nature of studies to find new anticancer agents makes it necessary to have well-designed studies. In the present study, the pathways that can be targeted for drug development are discussed in detail. Some of the important cellular origins, signaling, and pathways involved in the efficacy of bioactive molecules against CNS tumorigenesis or progression, as well as prognosis and common approaches for treatment of different types of brain tumors, are reviewed. Moreover, different study tools, including cell lines, in vitro, in vivo, and clinical trial challenges, are discussed. In addition, in this article, natural products as one of the most important sources for finding new chemotherapeutics were reviewed and over 700 reported molecules with efficacy against CNS cancer cells are gathered and classified according to their structure. Based on the clinical trials that have been registered, very few of these natural or semi-synthetic derivatives have been studied in humans. The review can help researchers understand the involved mechanisms and design new goal-oriented studies for drug development against CNS malignancies.

Hepa-ToxMOA: a pathway-screening method for evaluating cellular stress and hepatic metabolic-dependent toxicity of natural products

In the field of drug discovery, natural products have emerged as therapeutic agents for diseases such as cancer. However, their potential toxicity poses significant obstacles in the developing effective drug candidates. To overcome this limitation, we propose a pathway-screening method based on imaging analysis to evaluate cellular stress caused by natural products. We have established a cellular stress sensing system, named Hepa-ToxMOA, which utilizes HepG2 cells expressing green fluorescent protein (GFP) fluorescence under the control of transcription factor response elements (TREs) for transcription factors (AP1, P53, Nrf2, and NF-κB). Additionally, to augment the drug metabolic activity of the HepG2 cell line, we evaluated the cytotoxicity of 40 natural products with and without S9 fraction-based metabolic activity. Our finding revealed different activities of Hepa-ToxMOA depending on metabolic or non-metabolic activity, highlighting the involvement of specific cellular stress pathways. Our results suggest that developing a Hepa-ToxMOA system based on activity of drug metabolizing enzyme provides crucial insights into the molecular mechanisms initiating cellular stress during liver toxicity screening for natural products. The pathway-screening method addresses challenges related to the potential toxicity of natural products, advancing their translation into viable therapeutic agents.

Dioscin: Therapeutic potential for diabetes and complications

Diabetes mellitus is a widespread metabolic disorder with increasing incidence worldwide, posing a considerable threat to human health because of its complications. Therefore, cost-effective antidiabetic drugs with minimal side effects are urgently needed. Dioscin, a naturally occurring compound, helps to reduce the complications of diabetes mellitus by regulating glucose and lipid metabolism, protecting islet β cells, improving insulin resistance, and inhibiting oxidative stress and inflammatory response. Plant-derived dioscin reduces the risk of toxicity and side effects associated with chemically synthesized drugs. It is a promising option for treating diabetes mellitus because of its preventive and therapeutic effects, which may be attributed to a variety of underlying mechanisms. However, data compiled by current studies are preliminary. Information about the molecular mechanism of dioscin remains limited, and no high-quality human experiments and clinical trials for testing its safety and efficacy have been conducted. As a resource for research in this area, this review is expected to provide a systematic framework for the application of dioscin in the treatment of diabetes mellitus and its complications.

Protective effects of dioscin against Parkinson's disease via regulating bile acid metabolism through remodeling gut microbiome/GLP-1 signaling

It is necessary to explore potent therapeutic agents via regulating gut microbiota and metabolism to combat Parkinson's disease (PD). Dioscin, a bioactive steroidal saponin, shows various activities. However, its effects and mechanisms against PD are limited. In this study, dioscin dramatically alleviated neuroinflammation and oxidative stress, and restored the disorders of mice induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). 16 S rDNA sequencing assay demonstrated that dioscin reversed MPTP-induced gut dysbiosis to decrease Firmicutes-to-Bacteroidetes ratio and the abundances of Enterococcus, Streptococcus, Bacteroides and Lactobacillus genera, which further inhibited bile salt hydrolase (BSH) activity and blocked bile acid (BA) deconjugation. Fecal microbiome transplantation test showed that the anti-PD effect of dioscin was gut microbiota-dependent. In addition, non-targeted fecal metabolomics assays revealed many differential metabolites in adjusting steroid biosynthesis and primary bile acid biosynthesis. Moreover, targeted bile acid metabolomics assay indicated that dioscin increased the levels of ursodeoxycholic acid, tauroursodeoxycholic acid, taurodeoxycholic acid and β-muricholic acid in feces and serum. In addition, ursodeoxycholic acid administration markedly improved the protective effects of dioscin against PD in mice. Mechanistic test indicated that dioscin significantly up-regulated the levels of takeda G protein-coupled receptor 5 (TGR5), glucagon-like peptide-1 receptor (GLP-1R), GLP-1, superoxide dismutase (SOD), and down-regulated NADPH oxidases 2 (NOX2) and nuclear factor-kappaB (NF-κB) levels. Our data indicated that dioscin ameliorated PD phenotype by restoring gut dysbiosis and regulating bile acid-mediated oxidative stress and neuroinflammation via targeting GLP-1 signal in MPTP-induced PD mice, suggesting that the compound should be considered as a prebiotic agent to treat PD in the future.

UPLC-Q TOF-MS-Based metabolomics and anti-myocardial ischemia activity of Dioscoreae Nipponicae Rhizoma from different geographical origins

The dried rhizome of Dioscorea nipponica Makino ("Chuanshanlong" in Chinese) is a medicinal herb with multiple major producing areas. The main objective of this study was the comparative profiling of Dioscoreae Nipponicae Rhizoma (DNR) from various geographical origins. A hypoxia/reoxygenation-induced H9c2 cell injury model was established, and the antimyocardial ischemia activity of DNR samples from different origins was detected using the cell counting kit-8 (CCK-8) method. The result showed that the antimyocardial ischemia potential of DNR samples from the Heilongjiang province was higher than that of the other studied samples. Subsequently, a plant metabolomics technique utilizing ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q TOF-MS) was used to determine the differences in DNR samples from various geographical origins. Forty compounds, including steroidal saponins, free fatty acids, and organic acids, were tentatively identified based on UPLC-Q TOF-MS fragmentation pathways and via comparison with available reference standards. Partial least squares discriminant analysis was performed to estimate the differences in DNR samples from different origins. Five compounds were significantly up-regulated and correlated with antimyocardial ischemia in DNR samples from Heilongjiang province. Molecular docking was used to discern the interactions of key markers with the active sites of the target protein. The findings signified that UPLC-Q TOF-MS metabolomics coupled with molecular docking is a powerful tool to rapidly identify the quality control characteristics of DNR samples and their products. The research provides a direction for the rational utilization of DNR.

Toxicological effects of Saponin on the free larval stages of Schistosoma mansoni, infection rate, some biochemical and molecular parameters of Biomphalaria alexandrina snails

Saponins have been used as biopesticides. The objective of the present study is to investigate the toxic effects of Saponin against Biomphalaria alexandrina snails. Results showed that Saponin exhibited a molluscicidal activity against adult B. alexandrina snails at LC₅₀ (70.05 mg/l) and had a larvicidal effect on the free larval stages of Schistosoma mansoni. To evaluate the lethal effects, snails were exposed to either LC₁₀ (51.8 mg/l) or LC₂₅ (60.4 mg/l) concentrations of Saponin. The survival, the infection rates, protein, albumin, and total fat levels were decreased, while glucose levels were increased in exposed snails compared to control snails. Also, these concentrations significantly raised Malondialdehyde (MDA) and Glutathione S Transferase (GST) levels, whereas reduced Superoxide dismutase (SOD) activity and the total antioxidant capacity (TAC) in exposed snails. Furthermore, these concentrations resulted in endocrine disruptions where it caused a significant increase in testosterone (T) level; while a significant decrease in Estradiol (E2) levels were noticed. As for Estrogen (E) level, it was increased after exposure to LC₁₀ Saponin concentration while after exposure to LC₂₅ concentration, it was decreased. Also, LC₁₀ and LC₂₅ concentrations of Saponin caused a genotoxic effect and down-regulation of metabolic cycles in the snails. In conclusion, Saponins caused deleterious effects on the intermediate host of schistosomiasis mansoni. Therefore, B. alexandrina snails could be used as models to screen the toxic effects of Saponins in the aquatic environment and if it was used as a molluscicide, it should be used cautiously and under controlled circumstances.

In vitro evaluation of dioscin and protodioscin against ER-positive and triple-negative breast cancer

Women's breast cancer is one of the most significant healthcare issues for the human race that demands a proactive strategy for a cure. In this study, the cytotoxic activity (MTT assay) of two natural steroidal compounds, protodioscin and dioscin, against two major subtypes of human breast cancer estrogen receptor-positive (ER-positive)/MCF-7 and triple-negative breast cancer (TNBC)/MDA-MB-468), was assessed. The clonogenic capacity was evaluated using the clonogenic assay. Oxidative stress was determined by measuring the formation of malondialdehyde and H2O2 and the assessment of total antioxidant enzyme activities (SOD, GPx, GR, and TrxR). Protodioscin and dioscin were highly cytotoxic against the tested cell lines (1.53 μM <IC50< 6 μM) with low cytotoxicity on normal cells (PBMC; IC50 ≥ 50 μM). Interestingly, these compounds were responsible for a substantial decrease in the clonogenic capacity of both cell lines. Moreover, dioscin was able to reduce the cell motility of the invasive breast cancer cells (MDA-MB-468). At the molecular level, the two treatments resulted in an increase of reactive oxygen species. Notably, both compounds were responsible for decreasing the enzymatic activities of glutathione reductase and thioredoxin reductase. On the basis of such considerations, protodioscin and dioscin may serve as promising natural compounds to treat TNBC and ER-positive breast cancer through the induction of oxidative stress.

Diosgenin: An Updated Pharmacological Review and Therapeutic Perspectives

Plants including Rhizoma polgonati, Smilax china, and Trigonella foenum-graecum contain a lot of diosgenin, a steroidal sapogenin. This bioactive phytochemical has shown high potential and interest in the treatment of various disorders such as cancer, diabetes, arthritis, asthma, and cardiovascular disease, in addition to being an important starting material for the preparation of several steroidal drugs in the pharmaceutical industry. This review aims to provide an overview of the in vitro, in vivo, and clinical studies reporting the diosgenin's pharmacological effects and to discuss the safety issues. Preclinical studies have shown promising effects on cancer, neuroprotection, atherosclerosis, asthma, bone health, and other pathologies. Clinical investigations have demonstrated diosgenin's nontoxic nature and promising benefits on cognitive function and menopause. However, further well-designed clinical trials are needed to address the other effects seen in preclinical studies, as well as a better knowledge of the diosgenin's safety profile.

Dioscin: A review on pharmacological properties and therapeutic values

Dioscin has gained immense popularity as a natural, bioactive steroid saponin, which offers numerous medical benefits. The growing global incidence of disease-associated morbidity and mortality continues to compromise human health, facilitating an increasingly urgent need for nontoxic, noninvasive, and efficient treatment alternatives. Natural compounds can contribute vastly to this field. Over recent years, studies have demonstrated the remarkable protective actions of dioscin against a variety of human malignancies, metabolic disorders, organ injuries, and viral/fungal infections. The successful usage of this phytocompound has been widely seen in medical treatment procedures under traditional Chinese medicine, and it is becoming progressively prevalent worldwide. This review provides an insight into the wide spectrum of pharmacological activities of dioscin, as reported and compiled in recent literature. The various novel approaches and applications of dioscin also verify the advantages exhibited by plant extracts against commercially available drugs, highlighting the potential of phytochemical agents like dioscin to be further incorporated into clinical practice.

Cytotoxic activity of standardized extracts, a fraction, and individual secondary metabolites from fenugreek seeds against SKOV-3, HeLa and MOLT-4 cell lines

CONTEXT

Trigonella foenum-graecum L. (Fabaceae) has many therapeutic properties and anticancer potential.

OBJECTIVE

The cytotoxic activities of standardized extracts and a fraction from fenugreek seeds and their compounds (sapogenins, flavone C-glycosides, alkaloid trigonelline) against human cancer SKOV-3, HeLa and MOLT-4 cells were evaluated.

MATERIALS AND METHODS

Fenugreek seeds were extracted with 70% methanol (A) or water (B). Furthermore, the seeds were purified with petroleum ether and chloroform and next extracted with methanol to obtain fraction (C). The quantitative analysis of saponins and flavonoids in the extracts was done with HPLC methods. The extracts (5-120 µg/mL) and compounds (1-50 µg/mL) were tested on the cells by MTT assay and RTCA system. The effect of a fraction on ROS production, mitochondrial membrane potential and caspase-3/7 activity in HeLa and SKOV-3 cells was also evaluated by flow cytometry.

RESULTS

The strongest cytotoxic activity on cancer cells showed the fraction C (IC₅₀ was 3.91 ± 0.03 for HeLa, 3.97 ± 0.07 for SKOV-3, and 7.75 ± 0.37 for MOLT-4) with the highest content of steroidal saponins (163.18 ± 11.03 μg/mg) and flavone C-glycosides (820.18 ± 0.05 μg/mg). The fraction significantly increased ROS production (up to four times higher than in keratinocytes as control) and caspases activity in the cells. The examined flavonoids did not exhibit the cytotoxic activity in contrast to yamogenin, tigogenin, and diosgenin.

CONCLUSIONS

The obtained results complement the data on the cytotoxic activity of Foenugraeci Semen and synergistic effect of flavonoids and saponins complex contained in the plant.

Chrysophanol Induced Glioma Cells Apoptosis via Activation of Mitochondrial Apoptosis Pathway

Glioma is a common intracranial tumor originated from neuroglia cell. Chrysophanol is an anthraquinone derivative proved to exert anticancer effects in various cancers. This paper investigated the effect and mechanism of chrysophanol in glioma. Glioma cell lines U251 and SHG-44 were adopted in the experiments. The cells were treated with chrysophanol at different concentrations (0, 10, 20 50, 100 and 200 μM) for 48 h in the study, and then processed with MitoTempo. Mitochondria and cytosol were isolated to investigate the role of mitochondria during chrysophanol functioning on glioma cells. Cell viability was detected through 3-(4,5-Dimethyl-2-Thiazolyl)-2,5-Diphenyl Tetrazolium Bromide (MTT) assay, and cell apoptosis, cell cycle as well as relative reactive oxygen species (ROS) were assessed by flow cytometry. Expressions of Cytosol Cyt C, cleaved caspase-3, cleaved caspase-9, Cyclin D1 and Cyclin E were evaluated by western blot. In U251 and SHG-44 cells, with chrysophanol concentration rising, cell viability, expressions of Cyclin D1 and Cyclin E were decreased while cell apoptosis, levels of cleaved caspase-3, cleaved caspase-9 and Cytosol Cyt C as well as ROS accumulation were increased with cell cycle arrested in G1 phase. Besides, chrysophanol promoted ROS accumulation, cell apoptosis and transfer of Cyt C from mitochondria to cytosol in cells while MitoTempo partly reversed the effect of chrysophanol. Chrysophanol promoted cell apoptosis via activating mitochondrial apoptosis pathway in glioma.

An Overview of NO Signaling Pathways in Aging

Nitric Oxide (NO) is a potent signaling molecule involved in the regulation of various cellular mechanisms and pathways under normal and pathological conditions. NO production, its effects, and its efficacy, are extremely sensitive to aging-related changes in the cells. Herein, we review the mechanisms of NO signaling in the cardiovascular system, central nervous system (CNS), reproduction system, as well as its effects on skin, kidneys, thyroid, muscles, and on the immune system during aging. The aging-related decline in NO levels and bioavailability is also discussed in this review. The decreased NO production by endothelial nitric oxide synthase (eNOS) was revealed in the aged cardiovascular system. In the CNS, the decline of the neuronal (n)NOS production of NO was related to the impairment of memory, sleep, and cognition. NO played an important role in the aging of oocytes and aged-induced erectile dysfunction. Aging downregulated NO signaling pathways in endothelial cells resulting in skin, kidney, thyroid, and muscle disorders. Putative therapeutic agents (natural/synthetic) affecting NO signaling mechanisms in the aging process are discussed in the present study. In summary, all of the studies reviewed demonstrate that NO plays a crucial role in the cellular aging processes.

Saponins in Cancer Treatment: Current Progress and Future Prospects

Saponins are steroidal or triterpenoid glycoside that is distinguished by the soap-forming nature. Different saponins have been characterized and purified and are gaining attention in cancer chemotherapy. Saponins possess high structural diversity, which is linked to the anticancer activities. Several studies have reported the role of saponins in cancer and the mechanism of actions, including cell-cycle arrest, antioxidant activity, cellular invasion inhibition, induction of apoptosis and autophagy. Despite the extensive research and significant anticancer effects of saponins, there are currently no known FDA-approved saponin-based anticancer drugs. This can be attributed to a number of limitations, including toxicities and drug-likeness properties. Recent studies have explored options such as combination therapy and drug delivery systems to ensure increased efficacy and decreased toxicity in saponin. This review discusses the current knowledge on different saponins, their anticancer activity and mechanisms of action, as well as promising research within the last two decades and recommendations for future studies.

Insights into the antitumor mechanism of ginsenosides Rg3

Panax ginseng, an ancient herb, belonging to Chinese traditional medicine, is an important herb that has a remarkable impact on various diseases. Ginsenoside Rg3, one of the most abundant ginsenosides, exerts significant functions in the prevention of various types of cancers with few side effects. In the present review, its functional molecular mechanisms are explored, including the improvement of antioxidant and anti-inflammation properties, immune regulation, induction of tumor apoptosis, prevention of tumor invasion and metastasis, tumor proliferation and angiogenesis, and reduction of chemoresistance and radioresistance. On the other hand, metabolism, pharmacokinetics and clinical indications of Rg3 are also discussed. The biological functional role of ginsenoside Rg3 may be associated with that it is a steroid glycoside with diverse biological activities and many signaling pathway can be regulated. Many clinical trials are highly needed to confirm the functions of ginsenoside Rg3.

Eupafolin induces autophagy and apoptosis in B-cell non-Hodgkin lymphomas

OBJECTIVES

Eupafolin, an extract from Artemisia princeps, possesses multiple pharmacological activities. However, the effect of eupafolin on B-cell non-Hodgkin lymphomas is currently unknown. In this study, we report that eupafolin shows anticancer activity against B-cell non-Hodgkin lymphomas cell line, OCI-LY-3.

METHODS

A CCK-8 assay was used to detect the proliferation inhibition of OCI-LY-3 cells treated with additional concentrations of eupafolin. Flow cytometric analysis method of the cell apoptosis was detected after cells stained with Annexin-V-FITC/PI according to the manufacturer's instructions. The proteins in the cell were detected by western blot after treatment with eupafolin.

KEY FINDINGS

Eupafolin induced apoptosis in this cell line evidenced by the caspases activation, cleavage of PARP and downregulation of Bcl-2 and Bcl-xl. Eupafolin-induced autophagy was verified by accumulation of LC3-II and beclin-1. Eupafolin induced autophagy promoting apoptosis by the treatment of eupafolin combined with autophagy inhibitors 3-methyladenine and bafilomycin A1, respectively. Moreover, we disclose that the expression levels of p-Akt, p-mTOR,p-P70S6K and p-4EBP1 decrease in the Akt/mTOR signalling pathway, and the expression levels of proteins in the NF-ΚB signalling pathway, such as p-p65, p-IκBα, is downregulation.

CONCLUSIONS

Together, these results provide crucial evidences explaining the antitumour activity of eupafolin in human NHL cell line, OCI-LY-3.

Protective Role of Natural Products in Glioblastoma Multiforme: A Focus on Nitric Oxide Pathway

In spite of therapeutic modalities such as surgical resection, chemotherapy, and radiotherapy, Glioblastoma Multiforme (GBM) remains an incurable fatal disease. This necessitates further therapeutic options that could enhance the efficacy of existing modalities. Nitric Oxide (NO), a short-lived small molecule, has been revealed to play a crucial role in the pathophysiology of GBM. Several studies have demonstrated that NO is involved in apoptosis, metastasis, cellular proliferation, angiogenesis, invasion, and many other processes implicated in GBM pathobiology. Herein, we elaborate on the role of NO as a therapeutic target in GBM and discuss some natural products affecting the NO signaling pathway.

Peptide-functionalized liposomes as therapeutic and diagnostic tools for cancer treatment

Clinically efficacious medication in anticancer therapy has been successfully designed with liposome-based nanomedicine. The liposomal formulation in cancer drug delivery can be facilitated with a functionalized peptide that mediates the specific drug delivery opportunities with increased drug penetrability, specific accumulation in the targeted site, and enhanced therapeutic efficacy. This review aims to focus on recent advances in peptide-functionalized liposomal formulation techniques in cancer diagnosis and treatment regarding recently published literature. It also will highlight different aspects of novel liposomal formulation techniques that incorporate surface functionalization with peptides for better anticancer effect and current challenges in peptide-functionalized liposomal drug formulation.

Dioscin inhibits human endometrial carcinoma proliferation via G0/G1 cell cycle arrest and mitochondrial-dependent signaling pathway

The present study emphasized on the anti-cancerous effects of dioscin and its underlying molecular mechanism in human endometrial cancer Ishikawa cells. Dioscin significantly suppressed the proliferation of Ishikawa cells at IC₅₀ of 2.37 μM. Besides, dioscin could inhibit the proliferation of Ishikawa cells by blocking the G0/G1 cell cycle through up-regulation of p16, p21, and p27 and down-regulation of cycle-cellular protein (Cyclin A/D/E) and cyclin-dependent kinase (CDK2/4/6). Also, it promoted apoptosis through the mitochondrial pathway, including the regulation of Bcl family proteins, the increase of ROS levels, the activation of caspases (Caspase 9/3), and the decrease of mitochondrial membrane permeability. Whereas dioscin also effectively activated the marker genes and proteins (Fas, TNF-R1, and Caspase 8) related to the death receptor-mediated pathway which confirmed the involvement of both the pathways for dioscin-induced apoptosis. The current results demonstrated that dioscin possessed potential health benefits with respect to endometrial cancer prevention and treatment.

Molecular Mechanisms Underlying Intestinal Ischemia/Reperfusion Injury: Bioinformatics Analysis and In Vivo Validation

Background

Intestinal ischemia/reperfusion (I/R) injury is a serious clinical complication. This study aimed to explore the hub genes and pathways of intestinal I/R injury.

Material/Methods

GSE96733 from the GEO website was extracted to analyze the differentially expressed genes (DEGs) of intestinal I/R injured and sham-operated mice at 3 h and 6 h after surgery. The DAVID and STRING databases were used to construct functional enrichment analyses of DEGs and the protein–protein interaction (PPI) network. In Cytoscape software, cytoHubba was used to identify hub genes, and MCODE was used for module analysis. Testing by qRT-PCR detected the expression of hub genes in intestinal I/R injury. Western blot analysis detected the key proteins involved with the important pathways of intestinal I/R injury.

Results

IL-6, IL-10, CXCL1, CXCL2, and IL-1β were identified as critical upregulated genes, while IRF7, IFIT3, IFIT1, Herc6, and Oasl2 were identified as hub genes among the downregulated genes. The qRT-PCR testing showed the expression of critical upregulated genes was significantly increased in intestinal I/R injury (P<0.05), while the expression of hub downregulated genes was notably reduced (P<0.05). The proteins of CXCL1 and CXCR2 were upregulated following intestinal I/R injury (P<0.05) and the CXCL1/CXCR2 axis was involved with intestinal I/R injury.

Conclusions

The results of the present study identified IL-6, IL-10, CXCL1, CXCL2, IL-1β, IRF7, IFIT3, IFIT1, Herc6, and Oasl2 as hub genes in intestinal I/R injury and identified the involvement of the CXCL1/CXCR2 axis in intestinal I/R injury.

Antitumor effects of dioscin in A431 cells via adjusting ATM/p53-mediated cell apoptosis, DNA damage and migration

Skin cancer is the deadliest type of malignant disease and causes primary mortality worldwide. Dioscin, which exists in medicinal plants, has potent anticancer effects. However, its effects on skin cancer remain unknown. In the present study, the activity and mechanism of dioscin on the human skin cancer A431 cell line were investigated, MTT, colony formation, Transwell, wound-healing, TUNEL, Comet, immunofluorescence and western blot assays were used to assess the effects of dioscin on A431 cells. The results of MTT, colony formation, Transwell and wound-healing assays revealed that dioscin suppressed proliferation, colony formation and invasion of the cancer cells. TUNEL and comet assays demonstrated that dioscin exhibited significant effects on cell apoptosis and DNA damage. Investigations into the mechanism revealed that the expression levels of phosphorylated Ataxia telangiectasia-mutated (ATM) were considerably activated by dioscin, which significantly upregulated the expression levels of p53 to activate mitochondrial apoptosis signaling. Furthermore, the expression levels of BAX, cleaved caspase-3/9 and cleaved poly (ADP-ribose) polymerase were upregulated, and the expression levels of BCL-2 were downregulated by dioscin. Additionally, dioscin markedly downregulated the expression levels of matrix metalloproteinase 2 (MMP2), MMP9, RHO and cdc42, which are all associated with tumor invasion. In addition, p53-small interfering RNA transfection experiments indicated that dioscin exhibited excellent activity against skin cancer in vitro by decreasing p53 expression. Overall, the present results suggested that dioscin inhibited skin cancer cell proliferation via adjusting ATM/p53-mediated cell apoptosis, migration and DNA damage, which should be considered as a potential option for future treatments of skin cancer.

Diosgenin, a steroidal saponin, and its analogs: Effective therapies against different chronic diseases

BACKGROUND

Chronic diseases are a major cause of mortality worldwide, and despite the recent development in treatment modalities, synthetic drugs have continued to show toxic side effects and development of chemoresistance, thereby limiting their application. The use of phytochemicals has gained attention as they show minimal side effects. Diosgenin is one such phytochemical which has gained importance for its efficacy against the life-threatening diseases, such as cardiovascular diseases, cancer, nervous system disorders, asthma, arthritis, diabetes, and many more.

AIM

To evaluate the literature available on the potential of diosgenin and its analogs in modulating different molecular targets leading to the prevention and treatment of chronic diseases.

METHOD

A detailed literature search has been carried out on PubMed for gathering information related to the sources, biosynthesis, physicochemical properties, biological activities, pharmacokinetics, bioavailability and toxicity of diosgenin and its analogs.

KEY FINDINGS

The literature search resulted in many in vitro, in vivo and clinical trials that reported the efficacy of diosgenin and its analogs in modulating important molecular targets and signaling pathways such as PI3K/AKT/mTOR, JAK/STAT, NF-κB, MAPK, etc., which play a crucial role in the development of most of the diseases. Reports have also revealed the safety of the compound and the adaptation of nanotechnological approaches for enhancing its bioavailability and pharmacokinetic properties.

SIGNIFICANCE

Thus, the review summarizes the efficacy of diosgenin and its analogs for developing as a potent drug against several chronic diseases.

Antitumor effects of aconitine in A2780 cells via estrogen receptor β‑mediated apoptosis, DNA damage and migration

Ovarian cancer (OVCA) is the deadliest type of malignant gynecological disease, and previous studies have demonstrated that estrogen receptor β (ERβ) serves important roles in this disease. Aconitine, a toxin produced by the Aconitum plant, displays potent effects against cancers. The aim of the study was to investigate the pharmacological activities and mechanisms of aconitum on OVCA. In the present study, the activity of aconitine in the human OVCA A2780 cell line was investigated. The results revealed that aconitine suppressed cell viability, colony formation and motility. Terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling, mitochondria membrane potential and comet assays showed that aconitine induced mitochondria apoptosis and DNA damage in A2780 cells. Investigation of the mechanism revealed that a high expression of ERβ and prolyl hydroxylase 2 was detected after aconitine treatment, and aconitine significantly suppressed the expression of vascular endothelial growth factor and hypoxia-inducible factor 1α to activate ERβ signaling. Moreover, the expression levels of p53, Bax, apoptotic peptidase activating factor 1, cytochrome C, cleaved caspase-3/9 and cleaved poly (ADP-ribose) polymerase were upregulated, and the expression levels of Bcl-2, Bcl-xl and phosphorylated ATM serine/threonine kinase were downregulated by aconitine. Interestingly, aconitine also markedly downregulated the expression of matrix metalloproteinase 2 (MMP2) and MMP9, which are associated with tumor invasion. In addition, a molecular docking assay revealed that aconitine exerted strong affinity towards ERβ mainly through hydrogen bonding and hydrophobic effects. Collectively, these results suggested that aconitine suppressed OVCA cell growth by adjusting ERβ-mediated apoptosis, DNA damage and migration, which should be considered a potential option for the future treatment of OVCA.

Diosgenin and GSK126 Produce Synergistic Effects on Epithelial-Mesenchymal Transition in Gastric Cancer Cells by Mediating EZH2 via the Rho/ROCK Signaling Pathway

Background

Diosgenin, a natural steroidal saponin isolated from Trigonella foenum-graecum, has been reported to exert anti-cancer effects. Inhibitors of enhancer of zeste homology 2 (EZH2) have been widely used in treatment of cancers. However, the effects of combined treatment with diosgenin and an EZH2 inhibitor on gastric cancer (GC) cells, and the mechanism for those effects are not fully understood.

Methods

AGS and SGC-7901 gastric cancer cells were treated with diosgenin (0 to 8 μM), followed by treatment with either diosgenin or an EZH2 inhibitor, GSK126 alone. Afterwards, an EZH2 overexpression plasmid and Rho inhibitor, GSK429286A was involved in cells. Cell proliferation, cell cycle distribution, and cell apoptosis, migration, and invasion were examined by CCK-8 assays, flow cytometry, and transwell assays. Western blotting was performed to detect the relative levels of protein expression.

Results

Treatment with diosgenin alone caused a dose-dependent decrease in the cell viability, and combined treatment with an EZH2 inhibitor plus GSK126 caused a further significant decrease. A further analysis revealed that treatment with either diosgenin or GSK126 alone induced significant increases in G0/G1 cell cycle arrest and apoptosis, and combined treatment with both agents induced further increases in those parameters. In addition, combined treatment with diosgenin and GSK126 synergistically induced even stronger effects on impaired cell proliferation, G0/G1 phase arrest, and cell apoptosis when compared to treatment with either diosgenin or GSK126 treatment alone. At the molecular level, we demonstrated that inhibition of Rho/ROCK signaling by combined treatment with diosgenin and GSK126 could downregulate the expression of epithelial–mesenchymal transition (EMT)-related molecules. We also found that EZH2 overexpression reversed the anti-tumor effect of diosgenin by inducing cell survival, blocking G1-phase arrest, and promoted EMT. While, these biological properties were further reversed by GSK429286A.

Conclusion

Collectively, combined treatment with diosgenin and GSK126 produced even more significant effects on GC cell inhibition by targeting EZH2 via Rho/ROCK signaling-mediated EMT, which might be a therapeutic strategy for improving the poor therapeutic outcomes obtained with GSK126 monotherapy.

Radiation-synthesis of chitosan/poly (acrylic acid) nanogel for improving the antitumor potential of rutin in hepatocellular carcinoma

The current study aimed to investigate the ability of chitosan/poly (acrylic acid) nanogel (CAN) to improve the bioavailability and anticancer potential of rutin. Synthesis of CAN was carried out by gamma radiation-induced polymerization of acrylic acid in an aqueous solution of chitosan. The relationship between the hydrodynamic radius of CAN and the absorbed radiation doses was also investigated. The prepared nanogels were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) techniques, and then, it was used as a nano-drug carrier for rutin. The developed formulation was evaluated for its antitumor activity against chemically induced hepatocarcinoma in rats. The following parameters were measured: aspartate and alanine aminotransferase, alkaline phosphatase, gamma glutamyltransferase, and total bilirubin as liver function test; vascular endothelial growth factor as an angiogenesis marker; α-fetoprotein as a tumor marker; and P53, caspase-3, Bax, and Bcl-2 as apoptosis markers. Histopathological examination was also confirmed. Significant enhanced anti-proliferative, anti-angiogenic, and apoptotic effects were observed for rutin-loaded CAN than free rutin, indicating that this formulation could provide a novel therapeutic approach to serve as a promising agent for treatment of hepatocellular carcinoma. Graphical abstract.

Dioscin protects against diabetic nephropathy by inhibiting renal inflammation through TLR4/NF-κB pathway in mice

Diabetic nephropathy (DN) is a chronic kidney disease caused by the long-term loss of renal function, which occurs in 20% - 40% of all diabetes and is also the primary cause of end-stage renal diseases. DN is related with other lethal diseases, particularly cardiovascular diseases, leading to an increased risk of death. Therefore, an effective treatment for DN is required. Here we tested the protective effect of dioscin in a mouse model of streptozocin (STZ)-induced DN. First, STZ was intraperitoneally injected into C57BL/6 J mice and TLR4^-/- mice respectively, on a daily basis for 5 days to induce diabetes. Dioscin was then orally administered into diabetic mice daily for 8 weeks. Our results show that STZ injection effectively induced diabetes in mice as indicated by the increased blood glucose levels in C57BL/6 J mice, whereas it did not cause diabetes in TLR4^-/- mice. Dioscin significantly ameliorated STZ-induced renal damage via reducing inflammatory responses in diabetic mice and antagonizing the activation of TLR4/NF-κB pathway and the production of inflammatory cytokines. In conclusion, our study highlights the potential of dioscin as a novel approach to treat DN in diabetic patients.

New molecular and biochemical insights of doxorubicin-induced hepatotoxicity

Chemotherapeutic antibiotic doxorubicin belongs to the anthracycline class, slaughters not only the cancer cells but also non-cancerous cells even in the non-targeted organs thereby resulting in the toxicity. The liver is primarily involved in the process of detoxification and this mini-review we focused mainly to investigate the molecular mechanisms heading hepatotoxicity caused due to doxorubicin administration. The alterations in the doxorubicin treated liver tissue include vacuolation of hepatocytes, degeneration of hepatocyte cords, bile duct hyperplasia and focal necrosis. About the literature conducted, hepatotoxicity caused by doxorubicin has been explained by estimating the levels of liver serum biomarkers, ROS production, antioxidant enzymes, lipid peroxidation, and mitochondrial dysfunction. The liver serum biomarkers such as ALT and AST, elated levels of free radicals inducing oxidative stress characterized by a surge in Nrf-2, FOXO-1 and HO-1 genes and diminution of anti-oxidant activity characterized by a decline in SOD, GPx, and CAT genes. The augmented levels of SGOT, SGPT, LDH, creatine kinase, direct and total bilirubin levels also reveal the toxicity in the hepatic tissue due to doxorubicin treatment. The molecular insight of hepatotoxicity is mainly due to the production of ROS, ameliorated oxidative stress and inflammation, deteriorated mitochondrial production and functioning, and enhanced apoptosis. Certain substances such as extracts from medicinal plants, natural products, and chemical substances have been shown to produce an alleviating effect against the doxorubicin-induced hepatotoxicity are also discussed.

Molecular Targets for Combined Therapeutic Strategies to Limit Glioblastoma Cell Migration and Invasion

The highly invasive nature of glioblastoma imposes poor prospects for patient survival. Molecular evidence indicates glioblastoma cells undergo an intriguing expansion of phenotypic properties to include neuron-like signaling using excitable membrane ion channels and synaptic proteins, augmenting survival and motility. Neurotransmitter receptors, membrane signaling, excitatory receptors, and Ca2+ responses are important candidates for the design of customized treatments for cancers within the heterogeneous central nervous system. Relatively few published studies of glioblastoma multiforme (GBM) have evaluated pharmacological agents targeted to signaling pathways in limiting cancer cell motility. Transcriptomic analyses here identified classes of ion channels, ionotropic receptors, and synaptic proteins that are enriched in human glioblastoma biopsy samples. The pattern of GBM-enriched gene expression points to a major role for glutamate signaling. However, the predominant role of AMPA receptors in fast excitatory signaling throughout the central nervous system raises a challenge on how to target inhibitors selectively to cancer cells while maintaining tolerability. This review critically evaluates a panel of ligand- and voltage-gated ion channels and synaptic proteins upregulated in GBM, and the evidence for their potential roles in the pathological disease progress. Evidence suggests combinations of therapies could be more effective than single agents alone. Natural plant products used in traditional medicines for the treatment of glioblastoma contain flavonoids, terpenoids, polyphenols, epigallocatechin gallate, quinones, and saponins, which might serendipitously include agents that modulate some classes of signaling compounds highlighted in this review. New therapeutic strategies are likely to exploit evidence-based combinations of selected agents, each at a low dose, to create new cancer cell-specific therapeutics.

Therapeutic Potential of Diosgenin and Its Major Derivatives against Neurological Diseases: Recent Advances

Diosgenin (DG), a well-known steroidal sapogenin, is present abundantly in medicinal herbs such as Dioscorea rhizome, Dioscorea villosa, Trigonella foenum-graecum, Smilax China, and Rhizoma polgonati. DG is utilized as a major starting material for the production of steroidal drugs in the pharmaceutical industry. Due to its wide range of pharmacological activities and medicinal properties, it has been used in the treatment of cancers, hyperlipidemia, inflammation, and infections. Numerous studies have reported that DG is useful in the prevention and treatment of neurological diseases. Its therapeutic mechanisms are based on the mediation of different signaling pathways, and targeting these pathways might lead to the development of effective therapeutic agents for neurological diseases. The present review mainly summarizes recent progress using DG and its derivatives as therapeutic agents for multiple neurological disorders along with their various mechanisms in the central nervous system. In particular, those related to therapeutic efficacy for Parkinson's disease, Alzheimer's disease, brain injury, neuroinflammation, and ischemia are discussed. This review article also critically evaluates existing limitations associated with the solubility and bioavailability of DG and discusses imperatives for translational clinical research. It briefly recapitulates recent advances in structural modification and novel formulations to increase the therapeutic efficacy and brain levels of DG. In the present review, databases of PubMed, Web of Science, and Scopus were used for studies of DG and its derivatives in the treatment of central nervous system diseases published in English until December 10, 2019. Three independent researchers examined articles for eligibility. A total of 150 articles were screened from the above scientific literature databases. Finally, a total of 46 articles were extracted and included in this review. Keywords related to glioma, ischemia, memory, aging, cognitive impairment, Alzheimer, Parkinson, and neurodegenerative disorders were searched in the databases based on DG and its derivatives.

Dioscin alleviates lipopolysaccharide-induced acute lung injury through suppression of TLR4 signaling pathways

Aim: Acute lung injury (ALI) is a life-threatening inflammatory syndrome that lacks an effective therapy. Dioscin, a natural steroid saponin isolated from a variety of herbs, could serve as an anti-inflammatory agent, as suggested in previous reports. The purpose of this study was to explore the effects of dioscin on lipopolysaccharide (LPS)-induced ALI and validate the potential mechanisms.Materials and Methods: An ALI model was induced by intratracheal administration of LPS. Dioscin (20, 40, and 80 mg/kg) was administered intragastrically once daily for seven consecutive days prior to LPS challenge.Results: Our data revealed that dioscin significantly suppressed LPS-induced lung pathological changes, pulmonary capillary permeability, pulmonary edema, inflammatory cell infiltration, myeloperoxidase (MPO) activity, and cytokine production, including tumor necrosis factor (TNF)-α, interleukin (IL)-6, and keratinocyte chemoattractant (KC). Moreover, dioscin inhibited LPS-induced nuclear factor-kappaB (NF-κB) activation as well as Toll-like receptor 4 (TLR4) expression.Conclusions: In brief, the results indicated that dioscin alleviates LPS-induced ALI through suppression of TLR4 signaling pathways.

Coronarin D Induces Apoptotic Cell Death and Cell Cycle Arrest in Human Glioblastoma Cell Line

Glioblastoma (GBM) is the most frequent and highest-grade brain tumor in adults. The prognosis is still poor despite the use of combined therapy involving maximal surgical resection, radiotherapy, and chemotherapy. The development of more efficient drugs without noticeable side effects is urgent. Coronarin D is a diterpene obtained from the rhizome extract of Hedychium coronarium, classified as a labdane with several biological activities, principally anticancer potential. The aim of the present study was to determine the anti-cancer properties of Coronarin D in the glioblastoma cell line and further elucidate the underlying molecular mechanisms. Coronarin D potently suppressed cell viability in glioblastoma U-251 cell line, and also induced G1 arrest by reducing p21 protein and histone H2AX phosphorylation, leading to DNA damage and apoptosis. Further studies showed that Coronarin D increased the production of reactive oxygen species, lead to mitochondrial membrane potential depolarization, and subsequently activated caspases and ERK phosphorylation, major mechanisms involved in apoptosis. To our knowledge, this is the first analysis referring to this compound on the glioma cell line. These findings highlight the antiproliferative activity of Coronarin D against glioblastoma cell line U-251 and provide a basis for further investigation on its antineoplastic activity on brain cancer.

SK channel activation potentiates auranofin-induced cell death in glio- and neuroblastoma cells

Brain tumours are among the deadliest tumours being highly resistant to currently available therapies. The proliferative behaviour of gliomas is strongly influenced by ion channel activity. Small-conductance calcium-activated potassium (SK/K_Ca) channels are a family of ion channels that are associated with cell proliferation and cell survival. A combined treatment of classical anti-cancer agents and pharmacological SK channel modulators has not been addressed yet. We used the gold-derivative auranofin to induce cancer cell death by targeting thioredoxin reductases in combination with CyPPA to activate SK channels in neuro- and glioblastoma cells. Combined treatment with auranofin and CyPPA induced massive mitochondrial damage and potentiated auranofin-induced toxicity in neuroblastoma cells in vitro. In particular, mitochondrial integrity, respiration and associated energy generation were impaired. These findings were recapitulated in patient-derived glioblastoma neurospheres yet not observed in non-cancerous HT22 cells. Taken together, integrating auranofin and SK channel openers to affect mitochondrial health was identified as a promising strategy to increase the effectiveness of anti-cancer agents and potentially overcome resistance.

Dioscin attenuates oxLDL uptake and the inflammatory reaction of dendritic cells under high glucose conditions by blocking p38 MAPK

Dioscin has been shown to affect the regulation of metabolic diseases, including diabetes; however, the mechanism of action is still unclear. Under high glucose (HG) conditions, the expression of scavenger receptors and the uptake of oxidized low‑density lipoprotein (oxLDL) are upregulated in dendritic cells (DCs), which are critical steps in atherogenesis and inflammation. In this study, the focus was on the impact of dioscin on the function of DCs. Immature DCs were cultured with: 5.5 mM glucose medium (control group); 30 mM glucose medium (HG group); HG + 10 mM dioscin; HG + 20 mM dioscin; HG + 30 mM dioscin; and HG + 40 mM dioscin. For subsequent experiments, 30 mM dioscin was used as the experimental concentration. Dichlorodihydrofluorescein fluorescence was used to measure the intracellular production of reactive oxygen species (ROS) in DCs. The expression levels of the scavenger receptors, including class A scavenger receptors (SR‑A), CD36 and lectin‑like oxidized low‑density lipoprotein receptor‑1 (LOX‑1) were determined via quantitative PCR. The protein expression of p38 mitogen‑activated protein kinase (MAPK) was determined by western blotting. Furthermore, ELISA was used to detect the levels of interleukin (IL)‑6, IL‑10 and IL‑12. Finally, DCs were incubated with diOlistic (Dil)‑labeled oxLDL, and flow cytometry analysis was used to investigate the Dil‑oxLDL‑incorporated fraction. The incubation of DCs with dioscin inhibited the induction of ROS production, in a dose‑dependent manner, under HG conditions. The upregulation of SR‑A, CD36 and LOX‑1 genes was partially abolished by dioscin, which also partially reversed p38 MAPK protein upregulation. Furthermore, increased secretion of IL‑6 and IL‑12, and decreased secretion of IL‑10 in DCs, induced by HG, was also reversed by dioscin. To conclude, dioscin could attenuate the production of ROS, inflammatory cytokine secretion and oxLDL uptake by DCs in HG conditions by preventing the expression of scavenger receptors and p38 MAPK, thus playing a positive role in preventing atherogenesis.

Recent Advances in the Pharmacological Activities of Dioscin

Dioscin is a typical saponin with multiple pharmacological activities. The past few years have seen an emerging interest in and growing research on this pleiotropic saponin. Here, we review the emerging pharmacological activities reported recently, with foci on its antitumor, antimicrobial, anti-inflammatory, antioxidative, and tissue-protective properties. The potential use of dioscin in therapies of diverse clinical disorders is also discussed.

LY303511 displays antiproliferation potential against oral cancer cells in vitro and in vivo

LY303511 was developed as a negative control of LY294002 without pan-phosphoinositide 3-kinase (PI3K) inhibition. We hypothesize LY303511 generate reactive oxygen species (ROS) to induce apoptosis for killing oral cancer cells. In MTS assay, LY303511 dose-responsively decreases survival in three kinds of oral cancer cells but little damage to normal oral cells (HGF-1). Two oral cancer cells (CAL 27 and SCC-9) with highly sensitivity to LY303511 were used. In 7-aminoactinomycin D (7AAD) assay, LY303511 slightly increases subG1 population in oral cancer cells. In annexin V/7AAD and/or pancaspase assays, LY303511 induces apoptosis in oral cancer cells but HGF-1 cells remains in basal level. In oxidative stress, LY303511 induces ROS and mitochondrial superoxide in oral cancer cells. In 8-oxo-2'-deoxyguanosine assay, LY303511 induces oxidative DNA damage in oral cancer cells. In zebrafish model, LY303511 inhibits CAL 27-xenografted tumor growth. Therefore, LY303511 displays antiproliferation potential against oral cancer cells in vitro and in vivo.

Prospect of natural products in glioma: A novel avenue in glioma management

Glioma is one of the most perplexing cancers because of its infiltrating nature, molecular signaling, and location in central nervous system. Blood-brain barrier acts as a natural barrier to the glioma making it difficult to access by conventional chemotherapy. Clinicians are using natural compounds or their derivatives for several diseases including different cancers. However, the feasibility of using natural compounds in glioma is not explored in details. Natural compounds can act over a wide variety of signaling pathways such as survival and metabolic pathways and induce cell death. Some of the natural agents have additional benefits of crossing biological barriers such as blood-brain barrier with ease having few or no impact on the surrounding healthy cells. All of these benefits make natural compounds a prospective candidate for the glioma management. This article evaluates the benefits of using natural compounds for glioma therapy and their possible mechanism of actions. We have discussed the natural compounds assessed currently for glioma therapy and proposed a few novel natural compounds with potential antiglioma effect based on their mechanism of action.

N-Aminoacyl and N-hydroxyacyl derivatives of diosgenyl 2-amino-2-deoxy-β-d-glucopyranoside: Synthesis, antimicrobial and hemolytic activities

Diosgenyl 2-amino-2-deoxy-β-d-glucopyranoside is a semisynthetic saponin with antimicrobial and antitumor activities. To search for more effective analogues, N-aminoacyl and N-hydroxyacyl derivatives of this saponin were synthesized conventionally and with microwave assistance, and tested against the human pathogenic fungi and Gram-positive and Gram-negative bacteria. None of the tested compounds exhibit activity against Gram-negative bacteria. Almost all of the synthesized N-aminoacyl saponins exhibit antifungal activity and act effectively against Gram-positive bacteria, some better than the parent compound. The best acting saponins are the same size and possess sarcosine or l- or d-alanine attached to the parent glucosaminoside. Shorter and longer aminoacyl residues are less advantageous. d-Alanine derivative is the most effective against Gram positive bacteria. Structure-activity relationship (SAR) analysis indicates that the free α-amino group in aminoacyl residue is necessary for antimicrobial activities of the tested saponins. (N-Acetyl)aminoacyl and N-hydroxyacyl analogs are inactive. Measurements of the hemolytic activities demonstrate that the best acting saponins are not toxic towards human red blood cells.

Dioscin, a Steroidal Saponin Isolated from Dioscorea nipponica, Attenuates Collagen-Induced Arthritis by Inhibiting Th17 Cell Response

Dioscin, a steroidal saponin isolated from Dioscorea nipponica Makino, has previously been shown to possess antiarthritic effects. However, the underlying mechanism is still elusive. Herein, we investigated the therapeutic effects of dioscin on collagen-induced arthritis (CIA) in DBA/1 mice and related mechanism. Cytokine production in CII-specific immune responses were measured by enzyme-linked immunosorbent assay (ELISA); Th17 cell-related gene expression, including IL-17A, ROR[Formula: see text] and IL-23p19, were detected by qPCR analysis; Surface marker, T regulatory (Treg) cells and intracellular cytokines (IL-17A and IFN-[Formula: see text]) were evaluated by flow cytometry. We performed Th17 cell differentiation assay in vitro. Results showed that, in vivo, dioscin treatment significantly reduced the severity of CIA, which was accompanied by decreased Th17 response, but not Th1 and Treg response; dioscin-treated mice also showed lower percentage of CD11b[Formula: see text] Gr-1[Formula: see text] neutrophils; In vitro, dioscin treatment suppressed the differentiation of naive CD4[Formula: see text] T cells into Th17 cell and decreased IL-17A production. Collectively, our results indicate that dioscin exerts antiarthritic effects by inhibiting Th17 cell immune response.

Effects of Baicalin on piglet monocytes involving PKC-MAPK signaling pathways induced by Haemophilus parasuis

Background

Haemophilus parasuis (HPS) is the causative agent of Glässer’s disease, characterized by arthritis, fibrinous polyserositis and meningitis, and resulting in worldwide economic losses in the swine industry. Baicalin (BA), a commonly used traditional Chinese medication, has been shown to possess a series of activities, such as anti-bacterial, anti-viral, anti-tumor, anti-oxidant and anti-inflammatory activities. However, whether BA has anti-apoptotic effects following HPS infection is unclear. Here, we investigated the anti-apoptotic effects and mechanisms of BA in HPS-induced apoptosis via the protein kinase C (PKC)–mitogen-activated protein kinase (MAPK) pathway in piglet’s mononuclear phagocytes (PMNP).

Results

Our data demonstrated that HPS could induce reactive oxygen species (ROS) production, arrest the cell cycle and promote apoptosis via the PKC–MAPK signaling pathway in PMNP. Moreover, when BA was administered, we observed a reduction in ROS production, suppression of cleavage of caspase-3 in inducing apoptosis, and inhibition of activation of the PKC–MAPK signaling pathway for down-regulating p-JNK, p-p38, p-ERK, p-PKC-α and PKC-δ in PMNP triggered by HPS.

Conclusions

Our data strongly suggest that BA can reverse the apoptosis initiated by HPS through regulating the PKC–MAPK signaling pathway, which represents a promising therapeutic agent in the treatment of HPS infection.

Potent effects of dioscin against hepatocellular carcinoma through regulating TP53-induced glycolysis and apoptosis regulator (TIGAR)-mediated apoptosis, autophagy, and DNA damage

BACKGROUND AND PURPOSE

Dioscin shows potent effects against cancers. We aimed to elucidate its pharmacological effects and mechanisms of action on hepatocellular carcinoma (HCC) in vivo and in vitro.

EXPERIMENTAL APPROACH

Effects of dioscin were investigated in SMMC7721 and HepG2 cells, diethylnitrosamine-induced primary liver cancer in rats, and cell xenografts in nude mice. Isobaric tags for relative and absolution quantitation (iTRAQ)-based proteomics was used to find dioscin's targets and investigate its mechanism.

KEY RESULTS

In SMMC7721 and HepG2 cells dioscin markedly inhibited cell proliferation and migration, induced apoptosis, autophagy, and DNA damage. It inhibited DEN-induced primary liver cancer in rats, markedly changed body weights and restored levels of α fetoprotein, alanine transaminase, aspartate transaminase, γ-glutamyltransferase, alkaline phosphatase, and Ki67. It also inhibited growth of xenografts in mice. In SMMC7721 cells, 191 differentially expressed proteins were found after dioscin, based on iTRAQ-based assay. TP53-inducible glycolysis and apoptosis regulator (TIGAR) was identified as being significantly down-regulated by dioscin. Dioscin induced cell apoptosis, autophagy, and DNA damage via increasing expression levels of p53, cleaved PARP, Bax, cleaved caspase-3/9, Beclin-1, and LC3 and suppressing those of Bcl-2, p-Akt, p-mammalian target of rapamycin (mTOR), CDK5, p-ataxia telangiectasia-mutated gene (ATM). The transfection of TIGAR siRNA into SMMC7721 cells and xenografts in nude mice further confirmed that the potent activity of dioscin against HCC is evoked by adjusting TIGAR-mediated inhibition of p53, Akt/mTOR, and CDK5/ATM pathways.

CONCLUSIONS AND IMPLICATIONS

The data suggest that dioscin has potential as a therapeutic, and TIGAR as a drug target for treating HCC.

Advances in the antitumor activities and mechanisms of action of steroidal saponins

The steroidal saponins are one of the saponin types that exist in an unbound state and have various pharmacological activities, such as anticancer, anti-inflammatory, antiviral, antibacterial and nerves-calming properties. Cancer is a growing health problem worldwide. Significant progress has been made to understand the antitumor effects of steroidal saponins in recent years. According to reported findings, steroidal saponins exert various antitumor activities, such as inhibiting proliferation, inducing apoptosis and autophagy, and regulating the tumor microenvironment, through multiple related signaling pathways. This article focuses on the advances in domestic and foreign studies on the antitumor activity and mechanism of actions of steroidal saponins in the last five years to provide a scientific basis and research ideas for further development and clinical application of steroidal saponins.

Emodin induces apoptosis in human hepatocellular carcinoma HepaRG cells via the mitochondrial caspase‑dependent pathway

Emodin-induced hepatotoxicity in vivo and in vitro has been gaining increasing attention. However, the exact molecular pathways underlying these effects remain poorly clarified. The aim of the present study was to evaluate the cytotoxic effect of emodin on HepaRG cells and to define the underlying mechanism. The results demonstrated that emodin evidently inhibited HepaRG cell growth in a dose- and time-dependent manner by blocking cell cycle progression in the S and G2/M phase and by inducing apoptosis. Emodin treatment also resulted in generation of reactive oxygen species (ROS), which abrogated mitochondrial membrane potential (MMP). The above effects were all suppressed by antioxidants, such as N-acetylcysteine (NAC). Further studies by western blot analysis howed that emodin upregulated p53, p21, Bax, cyclin E, cleaved caspase-3, 8 and 9, and cleaved poly(ADP-ribose)polymerase (PARP). However, the protein expression of Bcl-2, cyclin A and CDK2 was downregulated. Taken together, our results suggest that emodin induces apoptosis via the mitochondrial apoptosis pathway through cell cycle arrest and ROS generation in HepaRG cells.

Dioscin inhibits colon cancer cells' growth by reactive oxygen species-mediated mitochondrial dysfunction and p38 and JNK pathways

Dioscin is a natural steroid saponin derived from several plants that shows potent anticancer effects against a variety of cancer cells. Here, we investigated the antitumor effect of dioscin against human colon cancer cells and evaluated the molecular mechanism involved in this process. The cell cytotoxicity was studied by the MTT assay and BrdU incorporation. The proapoptotic mechanism of dioscin was characterized by flow cytometry analysis. A western blot and an immunofluorescence staining were used to investigate how dioscin induces apoptosis in vitro. In our study, dioscin could significantly inhibit the growth of colon cancer cells in a time-dependent and dose-dependent manner. Dioscin induces apoptosis and reactive oxygen species (ROS) generation, promoting the disruption of mitochondrial membrane potential, Bax translocation to the mitochondria, cytochrome C release to cytosol, activations of caspase-9/3, PARP cleavage, and subsequent apoptosis. Dioscin-induced apoptosis was accompanied by sustained phosphorylation of JNK, p38-MAPK. N-acetyl-L-cysteine, a scavenger of ROS, significantly reversed dioscin-induced cell death and activation of JNK and p38. Collectively, the data indicate that the induction of apoptosis by dioscin is mediated through ROS proteins, which are critical upstream signals for JNK/p38-MAPK activation.

Dioscin overcome TKI resistance in EGFR-mutated lung adenocarcinoma cells via down-regulation of tyrosine phosphatase SHP2 expression

Resistance to tyrosine kinase inhibitors (TKIs) results in tumor relapse and poor prognosis in patients with lung adenocarcinoma. TKI resistance caused by epidermal growth factor receptor (EGFR) mutations at T790M and c-Met amplification occurs through persistent activation of the MEK/ERK and PI3K/AKT signaling pathways. We therefore expected that dual inhibitors of both signaling pathways could overcome TKI resistance in lung adenocarcinoma. Here, dioscin was selected from a product library of Chinese naturally occurring compounds and overcame TKI resistance in EGFR-mutated lung adenocarcinoma cells. Mechanistically, dioscin may down-regulate the expression of SH2 domain-containing phosphatase-2 (SHP2) at the transcription level by increasing p53 binding to the SHP2 promoter due to reactive oxygen species (ROS). Simultaneous inhibition of MEK/ERK and PI3K/AKT activation via decreased SHP2 expression and its interaction with GAB1 may be responsible for dioscin-mediated TKI sensitivity. A higher unfavorable response to TKI therapy occurred more commonly in patients with high SHP2 mRNA expression than in patients with low SHP2 mRNA expression. Therefore, we suggest that dioscin may act as a dual inhibitor of the MEK/ERK and PI3K/AKT signaling pathways to overcome TKI resistance via dysregulation of SHP2 expression in lung adenocarcinoma.