Triterpenoid Saponins from Anemone flaccida Suppress Tumor Cell Proliferation by Regulating MAPK, PD1/PDL1, and STAT3 Signaling Pathways and Altering Cancer Metabolism

STAT3 orchestrates immune dynamics in hepatocellular carcinoma: A pivotal nexus in tumor progression

Hepatocellular carcinoma (HCC) presents a formidable challenge in oncology, attributed to its association with chronic liver diseases and global prevalence. The immune microenvironment profoundly influences HCC progression, balancing immune suppression and antitumor responses. The Signal Transducer and Activator of Transcription 3 (STAT3) is central to this equilibrium, orchestrating immune dynamics and intertwining tumor progression with immune evasion mechanisms. Dysregulated STAT3 signaling, activated by various stimuli, including cytokines and growth factors, promotes an immunosuppressive milieu within HCC tumors, fostering tumor survival and proliferation while hindering immune surveillance. Non-coding RNAs and other molecules regulate this process, modulating STAT3 activity and influencing immune cell function. Moreover, therapeutic interventions targeting the STAT3 pathway, alongside advancements in radiotherapy, cancer vaccines, and diabetes-related drugs, offer promising strategies in HCC management. Integrating natural compounds with immunotherapy emerges as a novel approach, leveraging their ability to enhance antitumor immunity and counter immune evasion strategies. Understanding the multifaceted role of STAT3 and its interactions within the immune landscape of HCC is paramount for devising effective therapeutic interventions and improving patient outcomes.

Exploring Natural Compounds Targeting PD-L1 and STAT3: Toxicogenomic Analysis, Virtual Screening, Molecular Docking, ADMET Evaluation, and Biological Activity Prediction

BACKGROUND

One of the most important targets in cancer immunotherapy is programmed cell death ligand 1 (PD-L1). Monoclonal antibodies developed for this target have disadvantages due to their low bioavailability and some immune-related adverse effects. Additionally, small molecules targeting PD-L1 are still in the experimental stage. At this point, discovering non-toxic natural compounds that directly or indirectly target PD-L1 is essential. In this in silico study, a comprehensive literature search was conducted to identify publications reporting the master regulator of PD-L1, which was suggested as a Signal Transducer and Activator of Transcription 3 (STAT3). The relationship between STAT3 and PD-L1 was further investigated through bioinformatic analysis.

METHODS

Subsequently, natural compounds targeting PD-L1 and STAT3 were screened, and compounds with suitable toxicity profiles were docked against both PD-L1 and STAT3. Following molecular docking, the selected molecules underwent DNA docking, ADMET profile analysis, and in silico assessment of biological activities. The relationship between PD-L1 and STAT3 was determined in 52 out of the 453 articles, and it was further demonstrated in genegene interactions. Following the virtual screening, 76 natural compounds were identified, and after pre-filtering based on physicochemical properties, drug-likeness, and ADMET profiles, 29 compounds remained.

RESULTS

Subsequent docking revealed that two compounds, 6-Prenylapigenin, and Gelomulide J, persisted. ADMET and biological activity prediction results suggested that 6-Prenylapigenin is non-toxic and has the potential to inhibit PD-L1 and STAT3 in silico. The present study highlights that STAT3 serves as the master regulator of PD-L1, and it further suggests that 6- Prenylapigenin exhibits the potential to modulate PD-L1 and/or STAT3.

CONCLUSION

This finding could pave the way for the development of small molecules designed to block the PD-1/PD-L1 interaction by silencing the PD-L1 and/or STAT3 genes or reducing protein levels.

Paulownin elicits anti-tumor effects by enhancing NK cell cytotoxicity through JNK pathway activation

Paulownin, a natural compound derived from Paulownia tomentosa wood, exhibits various physiological functions, including anti-bacterial and anti-fungal effects. However, the impact of paulownin on natural killer (NK) cell immune activity remains largely unknown. In this study, we investigated the effect of paulownin on NK cell activity both in vitro and in vivo, and explored its potential mechanisms. NK-92 cells were used for in vitro experiments and a BALB/c mouse model with B16F10 cells injected subcutaneously were used for in vivo anti-tumor analysis. We found that paulownin enhanced the cytolytic activity of NK-92 cells against leukemia, human colon, and human lung cancer cell lines. Paulownin treatment increased the expression of the degranulation marker protein CD107a and cytolytic granules, including granzyme B and perforin in NK-92 cells. Moreover, these enhancements of cytotoxicity and the expression of cytolytic granules induced by paulownin were also observed in human primary NK cells. Signaling studies showed that paulownin promoted the phosphorylation of JNK. The increased perforin expression and elevated cytotoxic activity induced by paulownin were effectively inhibited by pre-treatment with a JNK inhibitor. In vivo studies demonstrated that the administration of paulownin suppressed the growth of B16F10 melanoma cells allografted into mice. Paulownin administration promoted the activation of NK cells in the spleen of mice, resulting in enhanced cytotoxicity against YAC-1 cells. Moreover, the anti-tumor effects of paulownin were reduced upon the depletion of NK cells. Therefore, these results suggest that paulownin enhances NK cell cytotoxicity by activating the JNK signaling pathway and provide significant implications for developing new strategies for cancer immunotherapy.

Cooperative STAT3-NFkB signaling modulates mitochondrial dysfunction and metabolic profiling in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) continues to pose a significant health challenge and is often diagnosed at advanced stages. Metabolic reprogramming is a hallmark of many cancer types, including HCC and it involves alterations in various metabolic or nutrient-sensing pathways within liver cells to facilitate the rapid growth and progression of tumours. However, the role of STAT3-NFκB in metabolic reprogramming is still not clear.

APPROACH AND RESULTS

Diethylnitrosamine (DEN) administered animals showed decreased body weight and elevated level of serum enzymes. Also, Transmission electron microscopy (TEM) analysis revealed ultrastructural alterations. Increased phosphorylated signal transducer and activator of transcription-3 (p-STAT3), phosphorylated nuclear factor kappa B (p-NFκβ), dynamin related protein 1 (Drp-1) and alpha-fetoprotein (AFP) expression enhance the carcinogenicity as revealed in immunohistochemistry (IHC). The enzyme-linked immunosorbent assay (ELISA) concentration of IL-6 was found to be elevated in time dependent manner both in blood serum and liver tissue. Moreover, immunoblot analysis showed increased level of p-STAT3, p-NFκβ and IL-6 stimulated the upregulation of mitophagy proteins such as Drp-1, Phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK-1). Meanwhile, downregulation of Poly [ADP-ribose] polymerase 1 (PARP-1) and cleaved caspase 3 suppresses apoptosis and enhanced expression of AFP supports tumorigenesis. The mRNA level of STAT3 and Drp-1 was also found to be significantly increased. Furthermore, we performed high-field 800 MHz Nuclear Magnetic Resonance (NMR) based tissue and serum metabolomics analysis to identify metabolic signatures associated with the progression of liver cancer. The metabolomics findings revealed aberrant metabolic alterations in liver tissue and serum of 75th and 105th days of intervention groups in comparison to control, 15th and 45th days of intervention groups. Tissue metabolomics analysis revealed the accumulation of succinate in the liver tissue samples, whereas, serum metabolomics analysis revealed significantly decreased circulatory levels of ketone bodies (such as 3-hydroxybutyrate, acetate, acetone, etc.) and membrane metabolites suggesting activated ketolysis in advanced stages of liver cancer.

CONCLUSION

STAT3-NFκβ signaling axis has a significant role in mitochondrial dysfunction and metabolic alterations in the development of HCC.

Natural bioactive compounds and STAT3 against hepatocellular carcinoma: An update

Hepatocellular carcinoma (HCC) is a challenging and very fatal liver cancer. The signal transducer and activator of transcription 3 (STAT3) pathway is a crucial regulator of tumor development and are ubiquitously active in HCC. Therefore, targeting STAT3 has emerged as a promising approach for preventing and treating HCC. Various natural bioactive compounds (NBCs) have been proven to target STAT3 and have the potential to prevent and treat HCC as STAT3 inhibitors. Numerous kinds of STAT3 inhibitors have been identified, including small molecule inhibitors, peptide inhibitors, and oligonucleotide inhibitors. Due to the undesirable side effects of the conventional therapeutic drugs against HCC, the focus is shifted to NBCs derived from plants and other natural sources. NBCs can be broadly classified into the categories of terpenes, alkaloids, carotenoids, and phenols. Most of the compounds belong to the family of terpenes, which prevent tumorigenesis by inhibiting STAT3 nuclear translocation. Further, through STAT3 inhibition, terpenes downregulate matrix metalloprotease 2 (MMP2), matrix metalloprotease 9 (MMP9) and vascular endothelial growth factor (VEGF), modulating metastasis. Terpenes also suppress the anti-apoptotic proteins and cell cycle markers. This review provides comprehensive information related to STAT3 abrogation by NBCs in HCC with in vitro and in vivo evidences.

Babao Dan Inhibits Gastric Cancer Progression in vivo through Multiple Signaling Pathways

Objective:

The aim of this study was to explore the effects of Babao dan (BBD), a traditional Chinese medicine, on gastric cancer (GC) progressionin vivo.

Materials and Methods:

A subcutaneous xenograft mouse model of GC was established using MGC80-3 cells. The terminal deoxynucleotidyl transferase-mediated dUTP: 2’-deoxyuridine 5’-triphosphate -biotin nick-end labeling method was adopted to detect cell apoptosisin vivo. The expression levels of proteins associated with proliferation, apoptosis, and angiogenesis were measured by immunohistochemical staining or western blotting (WB). The activation and protein levels of p-c-Jun N-terminal kinase (JNK), p-p38, p-extracellular-regulated kinase 1/2, p-nuclear factor-κB (NF-κB), and p-STAT3 were examined by Bio-plex and WB.

Results:

BBD significantly inhibited tumor growth in GC mouse models with no adverse effect on body weight or organ function. It was also found that BBD significantly suppressed the proliferation of GC tumor cells, induced the apoptosis of tumor cells, and inhibited angiogenesis through inactivating with mitogen-activated protein kinase, NF-κB, and STAT3 pathways.

Conclusions:

BBD exerts suppressive effects on GC tumor growth by regulating multiple pathwaysin vivo, which may provide a novel treatment option for GC therapy.

Thymus as Incontrovertible Target of Future Immune Modulatory Therapeutics

Thymus plays a crucial role in cellular immunity by acting as a warehouse for proliferating and differentiating lymphocytes. Thymic stromal cells educate T-cells to differentiate self from non-self antigens while nurse cells and thymoproteasome play a major role in the maturation and differentiation of T-cells. The thymic conditions dictate T-cells to cope with the risk of cancer development. A study was designed to demonstrate potential mechanisms behind the failure to eliminate tumors and impaired immune surveillance as well as the impact of delay in thymus regression on cancer and autoimmune disorders. Scientific literature from Pubmed; Scopus; WOS; JSTOR; National Library of Medicine Bethesda, Maryland; The New York Academy of Medicine; Library of Speech Rehabilitation, NY; St. Thomas' Hospital Library; The Wills Library of Guys Hospital; Repository of Kings College London; and Oxford Academic repository was explored for pathological, physiological, immunological and toxicological studies of thymus. Studies have shown that systemic chemotherapy may lead to micro inflammatory environment within thymus where conventionally and dynamically metastasized dormant cells seek refuge. The malfunctioning of the thymus and defective T and Treg cells, bypassing negative selection, contributes to autoimmune disorders, while AIRE and Fezf2 play significant roles in thymic epithelial cell solidity. Different vitamins, TCM, and live cell therapy are effective therapeutics. Vitamin A, C, D, and E, selenium and zinc, cinobufagin and dietary polysaccharides, and glandular extracts and live cell injections have strong potential to restore immune system function and thymus health. Moreover, the relationship between different ages/ stages of thymus and their corresponding T-cell mediated anti-tumor immune response needs further exploration.

Hyperoside Inhibits RNF8-mediated Nuclear Translocation of β-catenin to Repress PD-L1 Expression and Prostate Cancer

BACKGROUND

Hyperoside is a flavonol glycoside isolated from Hypericum perforatum L. that has inhibitory effects on cancer cells; however, its effects on prostate cancer (PCa) remain unclear. Therefore, we studied the anti-PCa effects of hyperoside and its underlying mechanisms in vitro and in vivo.

AIM

This study aimed to explore the mechanism of hyperoside in anti-PCa.

METHODS

3-(4,5-Dimethyl-2-Thiazolyl)-2,5-Diphenyl Tetrazolium Bromide (MTT), transwell, and flow cytometry assays were used to detect PCa cell growth, invasion, and cell apoptosis. Immunoblot analysis, immunofluorescence, immunoprecipitation, and quantitative real-time PCR (qRT-PCR) were used to analyze the antitumor mechanism of hyperoside.

RESULTS

Hyperoside inhibited PCa cell growth, invasion, and cell cycle and induced cell apoptosis. Furthermore, RING finger protein 8 (RNF8), an E3 ligase that assembles K63 polyubiquitination chains, was predicted to be a direct target of hyperoside and was downregulated by hyperoside. Downregulation of RNF8 by hyperoside impeded the nuclear translocation of β-catenin and disrupted the Wnt/β-catenin pathway, which reduced the expression of the target genes c-myc, cyclin D1, and programmed death ligand 1 (PD-L1). Decreased PD-L1 levels contributed to induced immunity in Jurkat cells in vitro. Finally, in vivo studies demonstrated that hyperoside significantly reduced tumor size, inhibited PD-L1 and RNF8 expression, and induced apoptosis in tumor tissues of a subcutaneous mouse model.

CONCLUSION

Hyperoside exerts its anti-PCa effect by reducing RNF8 protein, inhibiting nuclear translocation of β-catenin, and disrupting the Wnt/β-catenin pathway, in turn reducing the expression of PD-L1 and improving Jurkat cell immunity.

A Proposed Association between Improving Energy Metabolism of HepG2 Cells by Plant Extracts and Increasing Their Sensitivity to Doxorubicin

Increasing cancer cell sensitivity to chemotherapy by amending aberrant metabolism using plant extracts represents a promising strategy to lower chemotherapy doses while retaining the same therapeutic outcome. Here, we incubated HepG2 cells with four plant extracts that were selected based on an earlier assessment of their cytotoxicity, viz asparagus, green tea, rue, and avocado, separately, before treatment with doxorubicin. MTT assays elucidated a significant decrease in doxorubicin-IC₅₀ following HepG2 incubation with each extract, albeit to a variable extent. The investigated extract's ultra-performance liquid chromatography and gas chromatography coupled with mass spectrometry (UPLC/MS and GC/MS) revealed several constituents with anticancer activity. Biochemical investigation displayed several favorable effects, including the inhibition of hypoxia-inducible factor1α (HIF1α), c-Myc, pyruvate kinase-M2 (PKM2), lactate dehydrogenase-A (LDH-A), glucose-6-phosphate dehydrogenase (G6PD), and glutaminase by asparagus and rue extracts. To less extent, HIF1α, c-Myc, PKM2, and LDH-A were partially inhibited by green tea extract, and HIF1α and glutaminase activity was inhibited by avocado oil. Undesirably, green tea extract increased glutaminase; avocado oil rose c-Myc, and both increased G6PD. In conclusion, our study confirms the potential cytotoxic effects of these plant extracts. It highlights a strong association between the ability of asparagus, green tea, rue, and avocado to sensitize HepG2 cells to doxorubicin and their power to amend cell metabolism, suggesting their use as add-on agents that might aid in clinically lowering the doxorubicin dose.

Research advance of natural products in tumor immunotherapy

Cancer immunotherapy has emerged as a novel anti-tumor treatment. Despite significant breakthroughs, cancer immunotherapy remains focused on several types of tumors that are sensitive to the immune system. Therefore, effective strategies to expand its indications and improve its efficacy become key factors for the further development of cancer immunotherapy. In recent decades, the anticancer activities of natural products are reported to have this effect on cancer immunotherapy. And the mechanism is largely attributed to the remodeling of the tumor immunosuppressive microenvironment. The compelling data highlight that natural products offer an alternative method option to improve immune function in the tumor microenvironment (TME). Currently, more attention is being paid to the discovery of new potential modulators of tumor immunotherapy from natural products. In this review, we describe current advances in employing natural products and natural small-molecule drugs targeting immune cells to avoid tumor immune escape, which may bring some insight for guiding tumor treatment.

Medicinal Plants for the Treatment of Gastrointestinal Cancers From the Metabolomics Perspective

Gastrointestinal cancer (GIC), primarily including colorectal cancer, gastric cancer, liver cancer, pancreatic cancer, and esophageal cancer, is one of the most common causes of cancer-related deaths with increasing prevalence and poor prognosis. Medicinal plants have been shown to be a great resource for the treatment of GIC. Due to their complex manifestations of multi-component and multi-target, the underlying mechanisms how they function against GIC remain to be completely deciphered. Cell metabolism is of primary importance in the initialization and development of GIC, which is reported to be a potential target. As an essential supplement to the newest “omics” sciences, metabolomics focuses on the systematic study of the small exogenous and endogenous metabolites involved in extensive biochemical metabolic pathways of living system. In good agreement with the systemic perspective of medicinal plants, metabolomics offers a new insight into the efficacy assessment and action mechanism investigation of medicinal plants as adjuvant therapeutics for GIC therapy. In this review, the metabolomics investigations on metabolism-targeting therapies for GIC in the recent 10 years were systematically reviewed from five aspects of carbohydrate, lipid, amino acid, and nucleotide metabolisms, as well as other altered metabolisms (microbial metabolism, inflammation, and oxidation), with particular attention to the potential of active compounds, extracts, and formulae from medicinal plants. Meanwhile, the current perspectives and future challenges of metabolism-targeting therapies of medicinal plants for GIC were also discussed. In conclusion, the understanding of the action mechanisms of medicinal plants in GIC from the metabolomics perspective will contribute to the clinical application of potential candidates from the resourceful medicinal plants as novel and efficient adjuvant therapeutics for GIC therapy.

Emerging role of natural products in cancer immunotherapy

Cancer immunotherapy has become a new generation of anti-tumor treatment, but its indications still focus on several types of tumors that are sensitive to the immune system. Therefore, effective strategies that can expand its indications and enhance its efficiency become the key element for the further development of cancer immunotherapy. Natural products are reported to have this effect on cancer immunotherapy, including cancer vaccines, immune-check points inhibitors, and adoptive immune-cells therapy. And the mechanism of that is mainly attributed to the remodeling of the tumor-immunosuppressive microenvironment, which is the key factor that assists tumor to avoid the recognition and attack from immune system and cancer immunotherapy. Therefore, this review summarizes and concludes the natural products that reportedly improve cancer immunotherapy and investigates the mechanism. And we found that saponins, polysaccharides, and flavonoids are mainly three categories of natural products, which reflected significant effects combined with cancer immunotherapy through reversing the tumor-immunosuppressive microenvironment. Besides, this review also collected the studies about nano-technology used to improve the disadvantages of natural products. All of these studies showed the great potential of natural products in cancer immunotherapy.

OMICS Applications for Medicinal Plants in Gastrointestinal Cancers: Current Advancements and Future Perspectives

Gastrointestinal cancers refer to a group of deadly malignancies of the gastrointestinal tract and organs of the digestive system. Over the past decades, considerable amounts of medicinal plants have exhibited potent anticancer effects on different types of gastrointestinal cancers. OMICS, systems biology approaches covering genomics, transcriptomics, proteomics and metabolomics, are broadly applied to comprehensively reflect the molecular profiles in mechanistic studies of medicinal plants. Single- and multi-OMICS approaches facilitate the unravelling of signalling interaction networks and key molecular targets of medicinal plants with anti-gastrointestinal cancer potential. Hence, this review summarizes the applications of various OMICS and advanced bioinformatics approaches in examining therapeutic targets, signalling pathways, and the tumour microenvironment in response to anticancer medicinal plants. Advances and prospects in this field are also discussed.

Metabolomics Analysis Reveals the Differences Between Bupleurum chinense DC. and Bupleurum scorzonerifolium Willd

Bupleurum chinense DC. and Bupleurum scorzonerifolium Willd. are two varieties of Bupleuri Radix in Chinese Pharmacopoeia 2020. The clinical efficacy of the two bupleurum species is different. The difference in clinical efficacy is closely related to the composition of plant metabolites. In order to analyze the difference in metabolites, we used liquid chromatography coupled with mass spectrometry (LC-MS) for untargeted metabolome and gas chromatography coupled with mass spectrometry (GC-MS) for widely targeted metabolome to detect the roots (R), stems (S), leaves (L), and flowers (F) of two varieties, and detected 1,818 metabolites in 25 classes. We performed a statistical analysis of metabolites. Differential metabolites were screened by fold-change and variable importance in the projection values of the OPLS-DA model, and significant differences were found among different groups. The content of active components (triterpenoid saponins) was found to be high in the BcR group than in the BsR group. Other pharmacological metabolites were significantly different. By Kyoto Encyclopedia of Genes and Genomes annotation and enrichment analysis, we found that differential metabolites of the aboveground parts mainly concentrated in monoterpenoid biosynthesis, while the differential metabolites of the root mainly concentrated in sesquiterpenoid and triterpenoid biosynthesis. Differences in metabolic networks may indirectly affect the metabolic profile of Bc and Bs, leading to differences in clinical efficacy. Our study provides a scientific basis for subsequent biosynthesis pathway and related bioactivity research, and provides a reference for developing non-medicinal parts and guiding the clinical application of Bupleuri Radix.

Mechanism of drug-induced liver injury and hepatoprotective effects of natural drugs

Drug-induced liver injury (DILI) is a common adverse drug reaction (ADR) and a serious threat to health that affects disease treatments. At present, no targeted clinical drugs are available for DILI. Traditional natural medicines have been widely used as health products. Some natural medicines exert specific hepatoprotective effects, with few side effects and significant clinical efficacy. Thus, natural medicines may be a promising direction for DILI treatment. In this review, we summarize the current knowledge, common drugs and mechanisms of DILI, as well as the clinical trials of natural drugs and their bioactive components in anticipation of the future development of potential hepatoprotective drugs.

Role of Pentacyclic Triterpenoid Acids in the Treatment of Bladder Cancer

Bladder cancer carries a poor prognosis and has proven resistance to chemotherapy. Pentacyclic Triterpenoid Acids (PTAs) are natural bioactive compounds that have a well-known impact on cancer research because of their cytotoxic and chemopreventive activities. This review focuses on bladder cancer which can no longer be successfully treated by DNA damaging drugs. Unlike most of the existing drugs against bladder cancer, PTAs are non-toxic to normal cells. Collecting findings from both in vitro and in vivo studies, it has been concluded that PTAs may serve as promising agents in future bladder cancer therapy. In this review, the roles of various PTAs in bladder cancer have been explored, and their mechanisms of action in the treatment of bladder cancer have been described. Specific PTAs have been shortlisted from each of the chief skeletons of pentacyclic triterpenoids, which could be effective against bladder cancer because of their mode of action. This review thereby throws light on the multi targets and mechanisms of PTAs, which are responsible for their selective anticancer effects and provides guidelines for further research and development of new natural antitumor compounds.

Phytochemicals in Cancer Immune Checkpoint Inhibitor Therapy

The interaction of immune checkpoint molecules in the tumor microenvironment reduces the anti-tumor immune response by suppressing the recognition of T cells to tumor cells. Immune checkpoint inhibitor (ICI) therapy is emerging as a promising therapeutic option for cancer treatment. However, modulating the immune system with ICIs still faces obstacles with severe immunogenic side effects and a lack of response against many cancer types. Plant-derived natural compounds offer regulation on various signaling cascades and have been applied for the treatment of multiple diseases, including cancer. Accumulated evidence provides the possibility of efficacy of phytochemicals in combinational with other therapeutic agents of ICIs, effectively modulating immune checkpoint-related signaling molecules. Recently, several phytochemicals have been reported to show the modulatory effects of immune checkpoints in various cancers in in vivo or in vitro models. This review summarizes druggable immune checkpoints and their regulatory factors. In addition, phytochemicals that are capable of suppressing PD-1/PD-L1 binding, the best-studied target of ICI therapy, were comprehensively summarized and classified according to chemical structure subgroups. It may help extend further research on phytochemicals as candidates of combinational adjuvants. Future clinical trials may validate the synergetic effects of preclinically investigated phytochemicals with ICI therapy.

Chemical characterization of a PD-1/PD-L1 inhibitory activity fraction of the ethanol extract from Gymnadenia conopsea

Searching for PD-1/PD-L1 inhibitor from medicinal plants has become a potential method to discover small molecular cancer immunotherapy drugs. Using PD-1/PD-L1 inhibitory activity assay in vitro, a bioactive fraction was obtained from the ethanol extract of Gymnadenia conopsea. A sensitive UPLC-HRMS/MS method was established for the rapid screening and identification of compositions from bioactive fraction. Based on the characteristic fragmentation patterns of standards analysis and extracted ion chromatogram (EIC) method, 46 compounds were rapidly screened and identified (including 35 succinic acid ester glycosides and 11 other compounds), among which 17 compounds were tentatively identified as new compounds.

Kaempferide Induces G0/G1 Phase Arrest and Apoptosis via ROS-Mediated Signaling Pathways in A549 Human Lung Cancer Cells

Kaempferide is an O-methylated flavonol that has received much attention due to its various biological activities. In this study, we explored the underlying mechanisms of kaempferide in human lung cancer A549 cells. The Cell Counting Kit-8 (CCK-8) assay, Hoechst 33342/propidium iodide double staining, flow cytometry, scratch wound healing assay, and Western blot analysis were used to measure cell apoptosis, the cell cycle, reactive oxygen species (ROS) levels, and cell migration of human lung cancer cells. Kaempferide significantly inhibited human lung cancer cell proliferation, and its toxic effects on normal cells were significantly lower than those of 5-fluorouracil. Kaempferide induced A549 cell apoptosis by decreasing the mitochondrial membrane potential and the expression level of B-cell lymphoma 2, and by increasing the expression levels of Bcl-2-associated X protein and caspase-3. It also regulated mitogen-activated protein kinase (MAPK), signal transducer and activator of transcription 3 (STAT3), and nuclear factor kappa B (NF-κB) signaling pathways by increasing the expression levels of phosphorylated c-Jun N-terminal kinase, p-p38, I kappa B, and by decreasing the expression levels of phosphorylated extracellular signal-regulated kinase, p-STAT3, and NF-κB. Kaempferide induced cell cycle arrest in the G0/G1 phase in A549 cells by downregulating the expression levels of p-AKT, cyclin D1, and cyclin-dependent kinase 2. Furthermore, kaempferide blocked A549 cell migration by downregulating the expression levels of transforming growth factor beta 1 (TGF-β1), p-β-catenin, p-glycogen synthase kinase 3 beta, N-cadherin, and vimentin, and by upregulating the expression level of E-cadherin. Kaempferide enhanced the accumulation of ROS, and N-acetyl-l-cysteine (a ROS inhibitor) decreased the regulation of MAPK, NF-κB, AKT, and TGF-β signaling pathways by kaempferide, inhibited cell apoptosis, and reversed cell cycle arrest. Our results showed that kaempferide induced apoptosis via ROS-mediated MAPK, NF-κB, AKT, and TGF-β signaling pathways in A549 cells. Thus, kaempferide may be a novel drug candidate for lung cancer.

Using Traditional Chinese Medicine to Treat Hepatocellular Carcinoma by Targeting Tumor Immunity

As the leading cause of cancer-related death, hepatocellular carcinoma (HCC) threatens human health and limited treatments are available to cure the disease efficiently and effectively. The particularly immunotolerant environment of the liver lowers the efficacy of current therapies in patients with advanced HCC. Traditional Chinese medicine (TCM) is gathering increasing interest due to the immunoregulatory properties of certain compounds. In advanced HCC, TCM can restore immunosurveillance to promote antitumor effects in several ways, including the upregulation of immunostimulatory factors and the downregulation of immunosuppressive factors. The characteristic multitarget regulation of TCM compounds may provide new insights regarding effective HCC immunotherapies. Here, we review the immunoregulatory potency of TCMs for treating HCC and explain how individual TCM drugs and complex formulas remodel the immune environment in various cell- and cytokine-dependent manners.

Proposed mechanisms for the extracellular release of PD-L1 by the anticancer saponin platycodin D

Platycodin D (PTD) is an oleanane-type terpenoid saponin, isolated from the plant Platycodon grandiflorus. PTD displays multiple pharmacological effects, notably significant anticancer activities in vitro and in vivo. Recently, PTD was shown to trigger the extracellular release of the immunologic checkpoint glycoprotein PD-L1. The reduction of PD-L1 expression at the surface of cancer cells leads to interleukin-2 secretion and T cells activation. In the present review, we have analyzed the potential origin of this atypical PTD-induced PD-L1 release to propose a mechanistic explanation. For that, we considered all published scientific information, as well as the physicochemical characteristics of the natural product (a modeling analysis of PTD and the related saponin β -escin is provided). On this basis, we raise the hypothesis that the capacity of PTD to induce PD-L1 extracellular release derives from two main mechanisms: (i) a drug-promoted shedding of membrane PD-L1 by metalloproteases or more likely, (ii) a cholesterol binding-related effect, that would lead to perturbation of membrane raft domains, limiting the recruitment of proteins like TLR4. The drug-induced membrane effects (frequently observed with saponin drugs), associated with a production of interferon-γ,can favor the release of proteins like PD-L1 into membrane vesicles. Our analysis supports the hypothesis that PTD is a cholesterol-dependent lipid raft-modulating agent able to promote the formation of PD-L1 containing extracellular vesicles. The anticancer potential of PTD and its capacity to modulate the functioning of the PD-1/PD-L1 checkpoint should be further considered.