Physalin A exerts anti-tumor activity in non-small cell lung cancer cell lines by suppressing JAK/STAT3 signaling

Covalent binding of withanolides to cysteines of protein targets

Withanolides represent an important category of natural products with a steroidal lactone core. Many of them contain an α,β-unsaturated carbonyl moiety with a high reactivity toward sulfhydryl groups, including protein cysteine thiols. Different withanolides endowed with marked antitumor and anti-inflammatory have been shown to form stable covalent complexes with exposed cysteines present in the active site of oncogenic kinases (BTK, IKKβ, Zap70), metabolism enzymes (Prdx-1/6, Pin1, PHGDH), transcription factors (Nrf2, NFκB, C/EBPβ) and other structural and signaling molecules (GFAP, β-tubulin, p97, Hsp90, vimentin, Mpro, IPO5, NEMO, …). The present review analyzed the covalent complexes formed through Michael addition alkylation reactions between six major withanolides (withaferin A, physalin A, withangulatin A, 4β-hydroxywithanolide E, withanone and tubocapsanolide A) and key cysteine residues of about 20 proteins and the resulting biological effects. The covalent conjugation of the α,β-unsaturated carbonyl system of withanolides with reactive protein thiols can occur with a large set of soluble and membrane proteins. It points to a general mechanism, well described with the leading natural product withaferin A, but likely valid for most withanolides harboring a reactive (electrophilic) enone moiety susceptible to react covalently with cysteinyl residues of proteins. The multiplicity of reactive proteins should be taken into account when studying the mechanism of action of new withanolides. Proteomic and network analyses shall be implemented to capture and compare the cysteine covalent-binding map for the major withanolides, so as to identify the protein targets at the origin of their activity and/or unwanted effects. Screening of the cysteinome will help understanding the mechanism of action and designing cysteine-reactive electrophilic drug candidates.

Establishment of Physalis alkekengi cell suspension culture: time-dependent behavior of genes related to the steroidal compounds, key enzymes, and physalins under static magnetic field

Cell suspension culture has the potential to be a valuable source for the bioactive compound productions. In this study, an optimized procedure was established for callus and cell suspension culture of Physalis alkekengi for the first time, and the impact of static magnetic field (SMF, 6 mT) was studied on the high-value metabolic compounds through investigation of signaling molecules and gene expressions at the late log-to-stationary phase. Results showed that the growth regulators of 6-benzyl amino purine (BAP, 1.5 mg-1 L) and 1-naphthaleneacetic acid (NAA, 0.4 mg-1 L) induced the highest fresh weight, callus rate, callus index, and total withanolides. Cell suspension culture was established in the liquid MS medium supplied with BAP (1.5 mg-1 L) and NAA (0.1 mg-1 L). SMF application decreased slightly the cell growth and viability and enhanced the number of round-shaped cells. The hydrogen peroxide (H2O2) and nitric oxide (NO) levels increased at an all-time series after SMF exposure, and their maximum contents were observed after 12 h. A significant alteration of malondialdehyde content was also identified after 12 h of SMF exposure. The expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), 1-deoxyD-xylulose 5-phosphate synthase (DXS), squalene synthase (SQS), sterol Δ7-reductase (DWF5), and C-7,8 sterol isomerase (HYD1) genes was upregulated significantly after 24 and 48 h. An increase in the total withanolides was related to more activity of HMGR and DXS enzymes in SMF-exposed cells and the maximum physalin A (12.8 mg g-1 DW) and physalin B (1.92 mg g-1 DW) obtained after 24 h compared to controls. Findings suggest that SMF can play a supportive factor in inducing steroidal compounds in P. alkekengi through modulating H2O2 and NO levels and the related-gene expressions.

Michael Acceptors as Anti-Cancer Compounds: Coincidence or Causality?

Michael acceptors represent a class of compounds with potential anti-cancer properties. They act by binding to nucleophilic sites in biological molecules, thereby disrupting cancer cell function and inducing cell death. This mode of action, as well as their ability to be modified and targeted, makes them a promising avenue for advancing cancer therapy. We are investigating the molecular mechanisms underlying Michael acceptors and their interactions with cancer cells, in particular their ability to interfere with cellular processes and induce apoptosis. The anti-cancer properties of Michael acceptors are not accidental but are due to their chemical structure and reactivity. The electrophilic nature of these compounds allows them to selectively target nucleophilic residues on disease-associated proteins, resulting in significant therapeutic benefits and minimal toxicity in various diseases. This opens up new perspectives for the development of more effective and precise cancer drugs. Nevertheless, further studies are essential to fully understand the impact of our discoveries and translate them into clinical practice.

Investigating autophagy and intricate cellular mechanisms in hepatocellular carcinoma: Emphasis on cell death mechanism crosstalk

Hepatocellular carcinoma (HCC) stands as a formidable global health challenge due to its prevalence, marked by high mortality and morbidity rates. This cancer type exhibits a multifaceted etiology, prominently linked to viral infections, non-alcoholic fatty liver disease, and genomic mutations. The inherent heterogeneity of HCC, coupled with its proclivity for developing drug resistance, presents formidable obstacles to effective therapeutic interventions. Autophagy, a fundamental catabolic process, plays a pivotal role in maintaining cellular homeostasis, responding to stressors such as nutrient deprivation. In the context of HCC, tumor cells exploit autophagy, either augmenting or impeding its activity, thereby influencing tumorigenesis. This comprehensive review underscores the dualistic role of autophagy in HCC, acting as both a pro-survival and pro-death mechanism, impacting the trajectory of tumorigenesis. The anti-carcinogenic potential of autophagy is evident in its ability to enhance apoptosis and ferroptosis in HCC cells. Pertinently, dysregulated autophagy fosters drug resistance in the carcinogenic context. Both genomic and epigenetic factors can regulate autophagy in HCC progression. Recognizing the paramount importance of autophagy in HCC progression, this review introduces pharmacological compounds capable of modulating autophagy-either inducing or inhibiting it, as promising avenues in HCC therapy.

Physalin A Induces Apoptosis and Autophagy in Hepatocellular Carcinoma via Inhibition of PI3K/Akt Signaling Pathway

Physalin A (PA) is a bioactive withanolide with multiple pharmacological properties and has been indicated to be cytotoxic to hepatocellular carcinoma (HCC) cell line HepG2. This study aims to explore the mechanisms underlying PA antitumor activity in HCC. HepG2 cells were exposed to various concentrations of PA. Cell counting kit-8 assay and flow cytometry were implemented for evaluating cell viability and apoptosis, respectively. Immunofluorescence staining was utilized for detecting autophagic protein LC3. Western blotting was employed for measuring levels of autophagy-, apoptosis- and phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) signaling-related proteins. A xenograft mouse model was established to verify the antitumor activity of PA in vivo. PA impaired HepG2 cell viability, and triggered apoptosis as well as autophagy. Inhibiting autophagy augmented PA-evoked HepG2 cell apoptosis. PA repressed PI3K/Akt signaling in HCC cells and activating PI3K/Akt reversed PA-triggered apoptosis and autophagy. PA treatment inhibited tumor growth in tumor-bearing mice. PA triggers HCC cell apoptosis and autophagy by inactivating PI3K/Akt signaling.

Withanolides: Promising candidates for cancer therapy

Natural products have played a significant role throughout history in the prevention and treatment of numerous diseases, particularly cancers. As a natural product primarily derived from various medicinal plants in the Withania genus, withanolides have been shown in several studies to exhibit potential activities in cancer treatment. Consequently, understanding the molecular mechanism of withanolides could herald the discovery of new anticancer agents. Withanolides have been studied widely, especially in the last 20 years, and attracted the attention of numerous researchers. Currently, over 1200 withanolides have been classified, with approximately a quarter of them having been reported in the literature to be able to modulate the survival and death of cancer cells through multiple avenues. To what extent, though, has the anticancer effects of these compounds been studied? How far are they from being developed into clinical drugs? What are their potential, characteristic features, and challenges? In this review, we elaborate on the current knowledge of natural compounds belonging to this class and provide an overview of their natural sources, anticancer activity, mechanism of action, molecular targets, and implications for anticancer drug research. In addition, direct targets and clinical research to guide the design and implementation of future preclinical and clinical studies to accelerate the application of withanolides have been highlighted.

Research progress on the chemical components and pharmacological effects of Physalis alkekengi L. var. franchetii (Mast.) Makino

Physalis Calyx seu Fructus is the dry calyx or the calyx with fruit of the Solanaceae plant Physalis alkekengi L. var. franchetii (Mast.) Makino, with a long history of use in medicine and food. However, despite its many potential therapeutic and culinary applications, P. alkekengi is not being exploited for these applications on a large scale. This study analysed various research related to the different chemical components of P. alkekengi, including steroids, flavonoids, alkaloids, phenylpropanoids, sucrose esters, piperazines, volatile oils, polysaccharides, amino acids, and trace elements. In addition, research related to the pharmacological activities of P. alkekengi, including its anti-inflammatory, anti microbial, antioxidative, hypoglycaemic, analgesic, anti-tumour, and immunomodulatory effects were investigated. Research articles from 1974 to 2023 were obtained from websites such as Google Scholar, Baidu Scholar, and China National Knowledge Infrastructure, and journal databases such as Scopus and PubMed, with the keywords such as Physalis alkekengi, components, effects, and activities. This study aims to provide a comprehensive understanding of the progress of phytochemical and pharmacological research on the phytochemical and pharmacological aspects of P. alkekengi and a reference for the better exploitation of P. alkekengi in the food and pharmaceutical industries.

Molecular targets and mechanisms of anti-cancer effects of withanolides

Withanolides are a class of natural products with a steroidal lactone structure that exhibit a broad spectrum of anti-cancer effects. To date, several studies have shown that their possible mechanisms in cancer development and progression are associated with the regulation of cell proliferation, apoptosis, metastasis, and angiogenesis. Withanolides can also attenuate inflammatory responses, as well as modulate the genomic instability and energy metabolism of cancer cells. In addition, they may improve the safety and efficacy of cancer treatments as adjuvants to traditional cancer therapeutics. Herein, we summarize the molecular targets and mechanisms of withanolides in different cancers, as well as their current clinical studies on them.

Targeting Cell Signaling Pathways in Lung Cancer by Bioactive Phytocompounds

Lung cancer is a heterogeneous group of malignancies with high incidence worldwide. It is the most frequently occurring cancer in men and the second most common in women. Due to its frequent diagnosis and variable response to treatment, lung cancer was reported as the top cause of cancer-related deaths worldwide in 2020. Many aberrant signaling cascades are implicated in the pathogenesis of lung cancer, including those involved in apoptosis (B cell lymphoma protein, Bcl-2-associated X protein, first apoptosis signal ligand), growth inhibition (tumor suppressor protein or gene and serine/threonine kinase 11), and growth promotion (epidermal growth factor receptor/proto-oncogenes/phosphatidylinositol-3 kinase). Accordingly, these pathways and their signaling molecules have become promising targets for chemopreventive and chemotherapeutic agents. Recent research provides compelling evidence for the use of plant-based compounds, known collectively as phytochemicals, as anticancer agents. This review discusses major contributing signaling pathways involved in the pathophysiology of lung cancer, as well as currently available treatments and prospective drug candidates. The anticancer potential of naturally occurring bioactive compounds in the context of lung cancer is also discussed, with critical analysis of their mechanistic actions presented by preclinical and clinical studies.

Formulating co-loaded nanoliposomes with gallic acid and quercetin for enhanced cancer therapy

Cancer is considered one of the top global causes of death. Natural products have been used in oncology medicine either in crude form or by utilizing isolated secondary metabolites. Biologically active phytomolecules such as gallic acid and quercetin have confirmed antioxidant, anti-bacterial, and neoplastic properties. There is an agreement that microorganisms could mediate oncogenesis or alter the immune system. This research project aims to develop a novel formulation of co-loaded gallic acid and quercetin into nanoliposomes and investigate the efficacy of the free and combined agents against multiple cancerous cell lines and bacterial strains. Thin-film hydration technique was adopted to synthesize the nanocarriers. Particle characteristics were measured using a Zetasizer. The morphology of nanoliposomes was examined by scanning electron microscopy, Encapsulation efficiency and drug loading were evaluated using High-Performance Liquid Chromatography. Cytotoxicity was determined against Breast Cancer Cells MCF-7, Human Carcinoma Cells HT-29, and A549 Lung Cancer Cells. The antibacterial activities were evaluated against Acinetobacter baumannii, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, and Staphylococcus aureus. Therapeutic formulas were categorized into groups: free gallic acid, free quercetin, free-mix, and their nano-counterparts. Findings revealed that drug loading capacity was 0.204 for the mix formula compared to 0.092 and 0.68 for free gallic acid and quercetin, respectively. Regarding the Zeta potential, the mix formula showed more amphiphilic charge than the free quercetin and free gallic acid formulas (P-values 0.003 and 0.002 receptively). On the contrary, no significant difference in polydispersity indices was reported. Lung cancerous cells were the most affected by the treatments. The best estimated IC50 values were observed in breast and lung cancer lines for the nano-gallic acid and co-loaded particles. The nano-quercetin formula exhibited the least cytotoxicity with an IC50 value of ≥200 μg/mL in both breast (MCF-7) and colorectal adenocarcinoma cell lines (HT-29) with no activity against the lung. A remarkable improvement in the efficacy of quercetin was measured after mixing it with gallic acid against the breast and lungs. The tested therapeutic agents exhibited antimicrobial activity against gram-positive bacteria. Nano-liposomes can either enhance or reduce the cytotoxicity activity of active compounds depending on the physical and chemical properties of drug-loaded and type of cancer cells.

A Rapid and Sensitive LC−MS/MS Method for the Quantitation of Physalin A with Special Consideration to Chemical Stability in Rat Plasma: Application to a Pharmacokinetic Study

Physalin A is a promising natural product with excellent anti-inflammatory and anti-tumor activities. However, the pharmacokinetic profile of physalin A is still unclear. In this study, a rapid and sensitive analytical method based on LC–MS/MS for the quantitation of physalin A in rat plasma with special consideration to its chemical stability was developed and validated. To avoid the degradation of physalin A, the separation of plasma was conducted at 4 °C directly after the blood samples were collected. Meanwhile, plasma samples were immediately precipitated with acetonitrile containing tolbutamide (internal standard, IS) and the pH of the supernatant was adjusted to 1.5 with formic acid. Chromatographic separation of physalin A and IS was achieved on an ACQUITY UPLC BEH-C18 column (2.1 × 50 mm, 1.7 μm) using 0.1% formic acid and acetonitrile as mobile phase delivered at 0.3 mL/min in a gradient elution mode. Physalin A and IS were detected through negative ion electrospray ionization in multiple reaction monitoring (MRM) mode. The MS/MS ion transitions for physalin A and IS were m/z 525.1–148.9 and m/z 269.8–169.9, respectively. The developed method showed good linearity over the range of 2.00–400 ng/mL. This method was successfully applied to the pharmacokinetic study of physalin A in rats following its intragastric administration and the findings were beneficial for future studies of physalin A.

Discovery of physalin biosynthesis and structure modification of physalins in Physalis alkekengi L. var. Franchetii

Physalins, active ingredients from the Physalis alkekengi L. var. franchetii (P. alkekengi) plant, have shown anti-inflammatory, antioxidant and anticancer activities. Whereas the bioactivity of physalins have been confirmed, their biosynthetic pathways, and those of quite a few derivatives, remain unknown. In this paper, biosynthesis and structure modification-related genes of physalins were mined through transcriptomic and metabolomic profiling. Firstly, we rapidly and conveniently analyzed physalins by UPLC-Q-TOF-MS/MS utilizing mass accuracy, diagnostic fragment ions, and common neutral losses. In all, 58 different physalin metabolites were isolated from P. alkekengi calyxes and berries. In an analysis of the physalin biosynthesis pathway, we determined that withanolides and withaphysalins may represent a crucial intermediate between lanosterol and physalins. and those steps were decanted according to previous reports. Our results provide valuable information on the physalin metabolites and the candidate enzymes involved in the physalins biosynthesis pathways of P. alkekengi. In addition, we further analyzed differential metabolites collected from calyxes in the Jilin (Daodi of P. alkekengi) and others. Among them, 20 physalin metabolites may represent herb quality biomarkers for Daodi P. alkekengi, providing an essential role in directing the quality control index of P. alkekengi.

Physalis alkekengi L. var. franchetii (Mast.) Makino: A review of the pharmacognosy, chemical constituents, pharmacological effects, quality control, and applications

BACKGROUND

Physalis alkekengi L. var. franchetii (Mast.) Makino (PAF) (Chinese name Jin-Deng-Long) from the Solanaceae family is a traditional Chinese medicine with various pharmacological effects, such as removing heat, detoxification, improving throat conditions, removing phlegm, and ameliorating diuresis.

PURPOSE

This paper reviews the existing literature and patents and puts forward some suggestions for future PAF research.

METHODS

Using the PubMed, Google Scholar, Web of Science, and China National Knowledge Infrastructure databases, we performed comprehensive search of literature and patents published before April 2022 on PAF and its active ingredients.

RESULTS

We comprehensively reviewed the research progress of PAF from aspects of the traditional application, botany, chemical composition, pharmacological effects, and toxicology, and first discussed quality control and modern applications, which have not been explored in previous reviews. Thereafter, we reviewed the limitations of pharmacological mechanism and quality control studies and proposed appropriate solutions, which is of great practical significance to subsequent studies.

CONCLUSION

In this review, we present a comprehensive overview on PAF, and put forward new insights on studies regarding quality control, material basis, and mechanisms in classical prescription, providing theoretical guidance for the clinical application and development of Chinese medicine.

Inhibiting STAT3 signaling pathway by natural products for cancer prevention and therapy: In vitro and in vivo activity and mechanisms of action

Signal transducer and activator of transcription 3 (STAT3) plays a critical role in signal transmission from the plasma membrane to the nucleus, regulating the expression of genes involved in essential cell functions and controlling the processes of cell cycle progression and apoptosis. Thus, STAT3 has been elucidated as a promising target for developing anticancer drugs. Many natural products have been reported to inhibit the STAT3 signaling pathway during the past two decades and have exhibited significant anticancer activities in vitro and in vivo. However, there is no FDA-approved STAT3 inhibitor yet. The major mechanisms of these natural product inhibitors of the STAT3 signaling pathway include targeting the upstream regulators of STAT3, directly binding to the STAT3 SH2 domain and inhibiting its activation, inhibiting STAT3 phosphorylation and/or dimerization, and others. In the present review, we have systematically discussed the development of these natural product inhibitors of STAT3 signaling pathway as well as their in vitro and in vivo anticancer activity and mechanisms of action. Outlooks and perspectives on the associated challenges are provided as well.

Therapeutic Applications of Physalins: Powerful Natural Weapons

Physalins, or 16,24-cyclo-13,14-seco steroids, are compounds belonging to the class of withanolides that can be found in plants of Solanaceae family, mainly in species belonging to the genus Physalis spp., which are annual herbaceous plants widely distributed in tropical and subtropical regions of the world. Physalins are versatile molecules that act in several cell signaling pathways and activate different mechanisms of cell death or immunomodulation. A number of studies have shown a variety of actions of these compounds, including anticancer, anti-inflammatory, antiparasitic, antimicrobial, antinociceptive, and antiviral activities. Here we reviewed the main findings related to the anticancer, immunomodulatory, and antiparasitic activities of physalins and its mechanisms of action, highlighting the \challenges and future directions in the pharmacological application of physalins.

Natural Products from Physalis alkekengi L. var. franchetii (Mast.) Makino: A Review on Their Structural Analysis, Quality Control, Pharmacology, and Pharmacokinetics

The calyxes and fruits of Physalis alkekengi L. var. franchetii (Mast.) Makino (P. alkekengi), a medicinal and edible plant, are frequently used as heat-clearing and detoxifying agents in thousands of Chinese medicine prescriptions. For thousands of years in China, they have been widely used in clinical practice to treat throat disease, hepatitis, and bacillary dysentery. This systematic review summarizes their structural analysis, quality control, pharmacology, and pharmacokinetics. Furthermore, the possible development trends and perspectives for future research studies on this medicinal plant are discussed. Relevant information on the calyxes and fruits of P. alkekengi was collected from electronic databases, Chinese herbal classics, and Chinese Pharmacopoeia. Moreover, information was collected from ancient documents in China. The components isolated and identified in P. alkekengi include steroids, flavonoids, phenylpropanoids, alkaloids, nucleosides, terpenoids, megastigmane, aliphatic derivatives, organic acids, coumarins, and sucrose esters. Steroids, particularly physalins and flavonoids, are the major characteristic and bioactive ingredients in P. alkekengi. According to the literature, physalins are synthesized by the mevalonate and 2-C-methyl-d-erythritol-4-phosphate pathways, and flavonoids are synthesized by the phenylpropanoid pathway. Since the chemical components and pharmacological effects of P. alkekengi are complex and varied, there are different standards for the evaluation of its quality and efficacy. In most cases, the analysis was performed using high-performance liquid chromatography coupled with ultraviolet detection. A pharmacological study showed that the crude extracts and isolated compounds from P. alkekengi had extensive in vitro and in vivo biological activities (e.g., anti-inflammatory, anti-tumor, immunosuppressive, antibacterial, anti-leishmanial, anti-asthmatic, anti-diabetic, anti-oxidative, anti-malarial, anti-Alzheimer's disease, and vasodilatory). Moreover, the relevant anti-inflammatory and anti-tumor mechanisms were elucidated. The reported activities indicate the great pharmacological potential of P. alkekengi. Similarly, studies on the pharmacokinetics of specific compounds will also contribute to the progress of clinical research in this setting.

Assessing the Quality of Calyx of Physalis alkekengi L. var. franchetii Based on Quantitative Analysis of Q-Marker Combined with Chemometrics and Machine Learning Algorithms

Physalis alkekengi L. var. franchetii (PALF) is a traditional Chinese medicine, which is well known for its antimicrobial, anti-inflammatory, antipyretic, and expectorant properties. Its fruits and fruiting calyxes are used as dietary supplements and traditional herbs in China. However, the quality of calyxes is uneven, and it is prone to getting moldy or moth-eaten during storage. High-performance liquid chromatography (HPLC) fingerprints and multivariate chemometric methods were combined to evaluate quality, and three representative compounds were chosen as the quality markers (Q-markers). Hierarchical cluster analysis (HCA) and principal component analysis (PCA) provided a clear discrimination of PALF samples. Through further verification by partial least squares discriminant analysis (PLS-DA), backpropagation artificial neural network (BP-ANN), machine learning, and combination with the determination of the content, biology, and pharmacology effect judgment, galuteolin, rutin, and physalin O could be used as Q-markers that their contents affect the quality of PALF grade evaluation. A simple method was established to rapidly assess the quality of PALF that is important for its clinical application and storage and provide a reference for evaluating the quality of materials used in Chinese medicine.

Natural withanolides, an update

Covering: March 2010 to December 2020. Previous review: Nat. Prod. Rep., 2011, 28, 705This review summarizes the latest progress and perspectives on the structural classification, biological activities and mechanisms, metabolism and pharmacokinetic investigations, biosynthesis, chemical synthesis and structural modifications, as well as future research directions of the promising natural withanolides. The literature from March 2010 to December 2020 is reviewed, and 287 references are cited.

Anti-inflammatory action of physalin A by blocking the activation of NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Physalis Calyx seu Fructus is typically used to treat inflammatory diseases such as upper respiratory tract infection and acute tonsillitis in clinical practice of China. Physalin A, a main active ingredient of this traditional Chinese medicine (TCM), has been reported for its significant anti-tumor activity. However, most reports focused on the studies of its anti-tumor activity, the anti-inflammatory activity of physalin A and its molecular mechanism are still not elucidated clearly.

AIM OF THE STUDY

The aim of the study was to investigate the anti-inflammatory activities both in vitro and in vivo and molecular mechanism of physalin A.

MATERIALS AND METHODS

The potential anti-inflammatory properties of physalin A were evaluated in vitro by lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells, and in vivo via two typical acute inflammation murine models. Some important inflammation-related molecules were analyzed by enzyme-linked immuno sorbent assay (ELISA) and Western blotting.

RESULTS

The results showed that physalin A inhibited carrageenan-induced paw edema of rats and capillary permeability of mice induced by acetic acid in vivo. Furthermore, physalin A also significantly reduced the release of inflammatory mediators nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor-α (TNF-α) induced by lipopolysaccharide (LPS) in RAW 264.7 in vitro. Further investigations indicated that physalin A can down-regulate the high expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a dose-dependent manner. Physalin A remarkably blocked the degradation of inhibitor of nuclear factor kappa B alpha (IκB-α) and the nuclear translocation of nuclear factor-κB (NF-κB) p65 induced by LPS in RAW 264.7 cells. However, physalin A did not significantly inhibit the phosphorylation of mitogen-activated protein kinases (MAPKs) family proteins c-Jun N-terminal kinase (JNK) or extracellular signal-regulated kinase (ERK) or p38.

CONCLUSIONS

All the results clearly illustrated that the anti-inflammatory action of physalin A is due to the inactivation of NF-κB signal pathway, but is irrelevant to the MAPKs pathway.

Physalis alkekengi var. franchetii Extracts Exert Antitumor Effects on Non-Small Cell Lung Cancer and Multiple Myeloma by Inhibiting STAT3 Signaling

Background

Physalis alkekengi var. franchetii is an herb that possesses various ethnopharmacological applications. Herein, our current study focuses on the antitumor effect of a combination of physalins, which are regarded as the most representative secondary metabolites from calyces of Physalis alkekengi var. franchetii.

Materials and Methods

We mainly investigated the antitumor activity of the physalins extracted from Physalis alkekengi var. franchetii on both solid and hematologic cancers. The main cells used in this study were NCI-H1975 and U266 cells. The major assays used were the CCK-8 assay, Western blot analyses, immunofluorescence assay and Annexin V assay, and a xenograft mouse model was used.

Results

The results showed that physalins exhibited a strong antitumoural effect on both non-small cell lung cancer (NSCLC) and multiple myeloma (MM) cells by suppressing constitutive STAT3 activity and further inhibiting the downstream target gene expression induced by STAT3 signaling, which resulted in the enhanced apoptosis of tumor cells. Moreover, physalins significantly reduced tumor growth in xenograft models of lung cancer.

Conclusion

Collectively, these findings demonstrated that the physalins from Physalis alkekengi var. franchetii may potentially act as cancer preventive or chemotherapeutic agents for NSCLC and MM by inhibiting the STAT3 signaling pathway. The present study served as a promising guide to further explore the precise mechanism of Physalis alkekengi var. franchetii in cancer treatment.

Bioactive compounds induced in Physalis angulata L. by methyl-jasmonate: an investigation of compound accumulation patterns and biosynthesis-related candidate genes

We employed both metabolomic and transcriptomic approaches to explore the accumulation patterns of physalins, flavonoids and chlorogenic acid in Physalis angulata and revealed the genes associated with the biosynthesis of bioactive compounds under methyl-jasmonate (MeJA) treatment. Physalis angulata L. is an annual Solanaceae plant with a number of medicinally active compounds. Despite the potential pharmacological benefits of P. angulata, the scarce genomic information regarding this plant has limited the studies on the mechanisms of bioactive compound biosynthesis. To facilitate the basic understanding of the main chemical constituent biosynthesis pathways, we performed both metabolomic and transcriptomic approaches to reveal the genes associated with the biosynthesis of bioactive compounds under methyl-jasmonate (MeJA) treatment. Untargeted metabolome analysis showed that most physalins, flavonoids and chlorogenic acid were significantly upregulated. Targeted HPLC-MS/MS analysis confirmed variations in the contents of two important representative steroid derivatives (physalins B and G), total flavonoids, neochlorogenic acid, and chlorogenic acid between MeJA-treated plants and controls. Transcript levels of a few steroid biosynthesis-, flavonoid biosynthesis-, and chlorogenic acid biosynthesis-related genes were upregulated, providing a potential explanation for MeJA-induced active ingredient synthesis in P. angulata. Systematic correlation analysis identified a number of novel candidate genes associated with bioactive compound biosynthesis. These results may help to elucidate the regulatory mechanism underlying MeJA-induced active compound accumulation and provide several valuable candidate genes for further functional study.

Anticancer activities of phytoconstituents and their liposomal targeting strategies against tumor cells and the microenvironment

Various bioactive ingredients have been extracted from Chinese herbal medicines (CHMs) that affect tumor progression and metastasis. To further understand the mechanisms of CHMs in cancer therapy, this article summarizes the effects of five categories of CHMs and their active ingredients on tumor cells and the tumor microenvironment. Despite their treatment potential, the undesirable physicochemical properties (poor permeability, instability, high hydrophilicity or hydrophobicity, toxicity) and unwanted pharmacokinetic profiles (short half-life in blood and low bioavailability) restrict clinical studies of CHMs. Therefore, development of liposomes through relevant surface modifying techniques to achieve targeted CHM delivery for cancer cells, i.e., extracellular and intracellular targets and targets in tumor microenvironment or vasculature, have been reviewed. Current challenges of liposomal targeting of these phytoconstituents and future perspective of CHM applications are discussed to provide an informative reference for interested readers.

Long noncoding RNA PART1 promotes progression of non-small cell lung cancer cells via JAK-STAT signaling pathway

Non‐small cell lung cancer (NSCLC), the major type of lung cancer, becomes the greatest threat to the life of people. Growing evidence shows prostate androgen‐regulated transcript 1 (PART1) is considered as effective markers for prostate cancer, and has been shown to be associated with poor prognosis of NSCLC. However, the tumorigenic mechanism of PART1 in NSCLC remains to be investigated. In this study, we found that the expression of PART1 was robustly induced in NSCLC tissues and cell lines. Functional studies established that overexpression of PART1 could promote NSCLC cell proliferation, migration, and invasion, while interference of PART1 inhibited NSCLC progression. Our results also identified miR‐635 as a novel target of PART1, whose expression was inhibited by PART1 in NSCLC cell lines. Moreover, gain‐ and loss‐of‐function studies revealed that PART1 could sponge miR‐635 and increase the expression of Janus kinase (JAK) and signal transducer and activator of transcription proteins (STATs). Finally, we deciphered the molecular mechanism by which PART1 contributed to promotion of NSCLC cell progression via phosphorylation and activation of JAK‐STAT signaling pathway. The animal experiment further confirmed that interference of NSCLC could suppress in vivo tumorigenic ability of NSCLC with favorable pharmacological activity via inactivation of JAK‐STAT signaling pathway. In conclusion, our findings clarified the biologic significance of PART1/miR‐635/JAK‐STAT axis in NSCLC progression and provided novel evidence that PART1 may be a new potential therapeutic target for the treatment of NSCLC.

Physalin A regulates the Nrf2 pathway through ERK and p38 for induction of detoxifying enzymes

Background

Physalin A isolated from Physalis alkekengi var. franchetii has been known to have many pharmacological properties. However, its effect through the Nrf2 pathway has not yet been elucidated. In the present study, we determined the effects of physalin A on cancer chemoprevention via the Nrf2 pathway.

Methods

Experiments were performed in Hepa-1c1c7 and HepG2 cells. The quinone reductase (QR) activity assay was used to assess the activity of physalin A and other compounds isolated from P. alkekengi. The antioxidant response element (ARE) reporter assay was used to determine physalin A induced transcription of Nrf2 target genes, whereas the oligonucleotide pull-down assay was used to investigate Nrf2 binding to the AREs post physalin A treatment. Real-time PCR and western blotting were performed to determine the expression of Nrf2 target genes. Immunocytochemistry was used to determine Nrf2 localization after treatment with physalin A. Kinase inhibitors were used to test the involvement of Nrf2-targeting kinases and the role of ERK and p38 phosphorylation was confirmed using western blotting.

Results

Physalin A significantly induced QR activity. As an upstream effector of QR, Nrf2 induced genes containing the ARE, which encode various antioxidants and detoxification enzymes. We observed that physalin A increased the expression of Nrf2 and its target genes in HepG2 cells. Moreover, we observed that physalin A-induced Nrf2 activation was regulated by ERK and p38 kinase in HepG2 cells.

Conclusions

Taken together, we showed that physalin A increased detoxifying enzyme expression via activation of Nrf2 and its target genes. These results imply that physalin A could be a potential chemopreventive agent for liver diseases, as well as cancer.

Natural products as new antimitotic compounds for anticancer drug development

Cell cycle control genes are frequently mutated in cancer cells, which usually display higher rates of proliferation than normal cells. Dysregulated mitosis leads to genomic instability, which contributes to tumor progression and aggressiveness. Many drugs that disrupt mitosis have been studied because they induce cell cycle arrest and tumor cell death. These antitumor compounds are referred to as antimitotics. Vinca alkaloids and taxanes are natural products that target microtubules and inhibit mitosis, and their derivatives are among the most commonly used drugs in cancer therapy worldwide. However, severe adverse effects such as neuropathies are frequently observed during treatment with microtubule-targeting agents. Many efforts have been directed at developing improved antimitotics with increased specificity and decreased likelihood of inducing side effects. These new drugs generally target specific components of mitotic regulation that are mainly or exclusively expressed during cell division, such as kinases, motor proteins and multiprotein complexes. Such small molecules are now in preclinical studies and clinical trials, and many are products or derivatives from natural sources. In this review, we focused on the most promising targets for the development of antimitotics and discussed the advantages and disadvantages of these targets. We also highlighted the novel natural antimitotic agents under investigation by our research group, including combretastatins, withanolides and pterocarpans, which show the potential to circumvent the main issues in antimitotic therapy.

Physalin D regulates macrophage M1/M2 polarization via the STAT1/6 pathway

The in vitro and in vivo effects of physalin D on macrophage M1/M2 polarization were investigated. In silico analysis was first performed for biological function prediction of different physalins. The results suggest physalins have similar predicted biological functions due to their similarities in chemical structures. The cytotoxicity of physalins was then analyzed based on cell apoptosis rate and cell viability evaluation. Physalin D was chosen for further study due to its minimal cytotoxicity. Bone marrow macrophages were isolated and induced with lipopolysaccharide/interferon (IFN)-γ for M1 polarization and interleukin (IL)-4/IL-13 for M2 polarization. The results showed that physalin D can repolarize M1 phenotype cells toward M2 phenotype. In addition, physalin D is protective in M2 macrophages to maintain the M2 phenotype in the presence of IFN-γ. On the molecular level, we found that physalin D suppressed the signal transducers and activators of transcription (STAT)1 activation and blocked STAT1 nuclear translocation. Conversely, physalin D can also activate STAT6 and enhance STAT6 nuclear translocation for M2 polarization. Taken together, these results suggested that physalin D regulates macrophage M1/M2 polarization via the STAT1/6 pathway.

Licochalcone C induced apoptosis in human oral squamous cell carcinoma cells by regulation of the JAK2/STAT3 signaling pathway

Oral cancer is of an aggressive malignancy that arises on oral cavity and lip, 90% of cancers histologically originated in the squamous cells. Licochalcone (LC)C has been known as natural phenolic chalconoid substances, and its origin is the root of Glycyrrhiza glabra or Glycyrrhiza inflata. LCC inhibited oral squamous cell carcinoma (OSCC) cell viability, mitochondrial function, and anchorage-independent growth in a dose-dependent manner. To investigate the ability of LCC to target Janus kinase 2 (JAK2), we performed pull-down binding assay, kinase assay, and docking simulation. The molecular docking studies were performed between JAK2 and the potent inhibitor LCC. It was shown that LCC tightly interacted with ATP-binding site of JAK2. In addition, LCC inhibited the JAK2/signal transducer and activator of transcription 3 pathway, upregulated p21, and downregulated Bcl-2, Mcl-1, and Survivin, while it disrupted mitochondrial membrane potential and subsequently caused cytochrome c release with activation of multi-caspase, eventually leading to apoptosis in HN22 and HSC4 cells. LCC elevated the protein levels of Bax, cleaved Bid and PARP, and increased Apaf-1, and this effect was reversed by LCC treatment. Our results demonstrated that treatment of OSCC cells with LCC induced the death receptor (DR)4 and DR5 expression level with the generation of reactive oxygen species and the upregulation of CHOP protein expression. Taken together, these results could provide the basis for clinical application as a new therapeutic strategy in the treatment of oral cancer.

Effects of miR-126 on the STAT3 signaling pathway and the regulation of malignant behavior in lung cancer cells

The functions of miR-126-mediated signal transducers and activators of the transcription 3 (STAT3) signal pathway were investigated in regulating the behavior of cells in non-small cell lung cancer (NSCLC). Cultured NSCLC A549 cells were transfected with empty, miR-126 overexpression or miR-126 knocked-down expression plasmids. After transfection efficiency verification by reverse transcription polymerase chain reaction (RT-PCR) and culture for 24 h, methyl thiazolyl tetrazolium (MTT) was applied to detect cell proliferation rate, migration distance was measured in scratch assays, cell cycle was determined through flow cytometry, the mRNA expression level of caspase-3 in cells was detected using RT-PCR and protein expression levels of STAT3 were detected using western blotting. Our results showed the cell proliferation rate was significantly higher in cells of the overexpression group than that in those of the control group (p<0.05) and the rate in the cells of the low-expression group was the lowest among the three groups (p<0.05). The migration distance of the overexpression group cells was significantly longer than that in the control group cells and the shortest migration distance was found in the low-expression group cells (p<0.05). The amount of cells in mitotic phase in the overexpression group was significantly higher than that in the control group and the same amount in the low-expression group was the lowest (p<0.05). The mRNA expression level of caspase-3 of cells in the overexpression group was significantly lower than that of cells in the control group and the highest expression level was found in the low-expression group (p<0.05). Finally, the protein expression levels of STAT3 in cells in the overexpression group were significantly lower than those in the control group and the highest expression levels were identified in the low-expression group (p<0.05). Based on our findings, the cancer-promoting miR-126 can mediate the activation of the STAT3 signal pathway to regulate the malignant biological behavior of NSCLC cells affecting their proliferation, migration, cycle and apoptosis susceptibility.

Physakengose G induces apoptosis via EGFR/mTOR signaling and inhibits autophagic flux in human osteosarcoma cells

BACKGROUND

Physakengose G (PG) is a new compound first isolated from Physalis alkekengi var. franchetii, an anticarcinogenic traditional Chinese medicine. PG has shown promising anti-tumor effects, but its underlying mechanisms remain unknown.

PURPOSE

To investigate the anti-cancer effects of PG on human osteosarcoma cells and the underlying mechanisms.

METHODS

Cell viability was measured by MTT assay. Apoptosis rates, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) generation, and acidic vesicular organelles (AVOs) formation were determined by flow cytometry. Protein levels were analyzed by immunofluorescence and western blotting.

RESULTS

PG inhibited cell proliferation and induced apoptosis in human osteosarcoma cells. PG treatment blocked EGFR phosphorylation and suppressed epidermal growth factor (EGF)-induced activation of downstream signaling molecules, such as AKT and mTOR. PG treatment resulted in lysosome dysfunction by altering lysosome acidification and LAMP1 levels, which led to autophagosome accumulation and autophagic flux inhibition.

CONCLUSION

PG inhibits cell proliferation and EGFR/mTOR signaling in human osteosarcoma cells. Moreover, PG induces apoptosis through the mitochondrial pathway and impedes autophagic flux via lysosome dysfunction. Our findings indicate that PG has the potential to play a significant role in the treatment of osteosarcoma.

Withapubesides A-D: natural inducible nitric oxide synthase (iNOS) inhibitors from Physalis pubescens

Four new steroid glycosides, withapubesides A-D (1-4), were isolated from the stems of Physalis pubescens L. Their structures were elucidated primarily by NMR experiments. The absolute configurations of 1 and 2 were deduced by single-crystal X-ray diffraction and ECD data analysis, respectively. Compound 3 has shown significant inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages with an IC₅₀ value of 12.8 μM and moderate cytostatic activity against human carcinoma cells (786-O, C4-2B, 22Rvl, A375 and A375S2) with IC₅₀ values in the range of 3.05-9.47 μM. Molecular docking simulation demonstrated that 3 is bound in the inducible nitric oxide synthase (iNOS) active site heme pocket very well, which suggests that 3 might be a candidate for the development of iNOS inhibitors.

Physalis alkekengi L. var. franchetii (Mast.) Makino: An ethnomedical, phytochemical and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

The calyxes and fruits of Physalis alkekengi L. var. franchetii (Mast.) Makino (Physalis Calyx seu Fructus), have been widely used in traditional and indigenous Chinese medicines for the therapy of cough, excessive phlegm, pharyngitis, sore throat, dysuria, pemphigus, eczema, and jaundice with a long history.

AIM OF THE REVIEW

The present review aims to achieve a comprehensive and up-to-date investigation in ethnomedical uses, phytochemistry, pharmacology, and toxicity of P. alkekengi var. franchetii, particularly its calyxes and fruits. Through analysis of these findings, evidences supporting their applications in ethnomedicines are illustrated. Possible perspectives and opportunities for the future research are analyzed to highlight the gaps in our knowledge that deserves further investigation.

MATERIAL AND METHODS

Information on P. alkekengi var. franchetii was collected via electronic search of major scientific databases (e.g. Web of Science, SciFinder, Google Scholar, Pubmed, Elsevier, SpringerLink, Wiley online and China Knowledge Resource Integrated) for publications on this medicinal plant. Information was also obtained from local classic herbal literature on ethnopharmacology.

RESULTS

About 124 chemical ingredients have been characterized from different parts of this plant. Steroids (particularly physalins) and flavonoids are the major characteristic and bioactive constituents. The crude extracts and the isolated compounds have demonstrated various in vitro and in vivo pharmacological functions, such as anti-inflammation, inhibition of tumor cell proliferation, antimicrobial activity, diuretic effect, anti-diabetes, anti-asthma, immunomodulation, and anti-oxidation.

CONCLUSIONS

P. alkekengi var. franchetii is an important medicinal plant for the ethnomedical therapy of microbial infection, inflammation, and respiratory diseases (e.g. cough, excessive phlegm, pharyngitis). Phytochemical and pharmacological investigations of this plant definitely increased in the past half century. The chemical profiles, including ingredients and structures, have been adequately verified. Modern pharmacological studies supported its uses in the traditional and folk medicines, however, the molecular mechanisms of purified compounds remained unclear and were worth of further exploration. Therefore, the researchers should be paid more attention to a better utilization of this plant.

Expression, purification and characterization of a catalytic domain of human protein tyrosine phosphatase non-receptor 12 (PTPN12) in Escherichia coli with FKBP-type PPIase as a chaperon

Protein tyrosine phosphatase non-receptor type 12 (PTPN12), also known as PTP-PEST, was broadly expressed in hemopoietic cells. Recent research has shown that this enzyme is involved in tumorigenesis, as well as in tumor progression and transfer, as it can suppress multiple oncogenic tyrosine kinases. However, the difficulty of soluble expression of PTP-PEST in prokaryotic cells has resulted in great limitations in investigating its structure and functions. In this study, we successfully carried out soluble expression of the catalytic domain of PTP-PEST (ΔPTP-PEST) in Escherichia coli and performed an enzymatic characterization and kinetics. To confirm expression efficiency, we also induced the expression of the chaperon, FKBP_C. FKBP_C expression indicated efficacious prokaryotic expression of ΔPTP-PEST. In conclusion, our work yielded a practical expression system and two-step chromatography purification method that may serve as a valuable tool for the structural and functional analysis of proteins that are difficult to express in the soluble form in prokaryotic cells.

Induction of autophagy by an oleanolic acid derivative, SZC017, promotes ROS-dependent apoptosis through Akt and JAK2/STAT3 signaling pathway in human lung cancer cells

The signal transducers and activators of transcription 3 (STAT3) signaling pathway is a common feature in many solid tumors including non-small cell lung cancer, whereas current therapies usually fail to treat this disease in majority of cases. In the present study, we aimed to investigate the cytotoxic effect and the underlying mechanisms of SZC017, an oleanolic acid derivative, on human lung cancer cells. Cell viability was significantly decreased in SZC017-treated lung cancer cells. Mechanistically, SZC017 reduced A549 cell viability by activating both apoptosis and autophagy pathways. SZC017 was able to inhibit the phosphorylation of Akt, JAK2, and STAT3 in A549 cells, resulting in the inactivation of Akt and JAK2/STAT3 signaling pathways. In addition, SZC017 could induce ROS generation and Ca²⁺ release. Pretreatment with N-Acetyl L-Cysteine, a ROS scavenger, could fully reverse SZC017-induced ROS and increase the expression of Akt, p-STAT3, and procaspase-3, while decrease the ratio of LC3-II/I and the expression of Beclin-1. In summary, our study provides pharmacological evidence that SZC017 exhibits potential use in the treatment of lung cancer.

MicroRNA-148a suppresses proliferation and invasion potential of non-small cell lung carcinomas via regulation of STAT3

Lung cancer has the highest morbidity and mortality in the world, and non-small cell lung carcinomas (NSCLC) account for 80% of cases of lung cancer. The mechanism of NSCLC is still largely unknown, and finding novel targets is of great importance for the treatment of NSCLC. The current study was designed to evaluate the role of miR-148a in NSCLC cell proliferation and invasion and to investigate the possible molecular mechanisms. We found that miR-148a expression was decreased in NSCLC tissues and cell lines. Upregulation of miR-148a significantly decreased A549 cell proliferation, and downregulation of miR-148a significantly increased A549 cell proliferation. Upregulation of miR-148a markedly increased apoptotic cell death and inhibited cell invasion potential. Upregulation of miR-148a significantly decreased signal transducer and activator of transcription 3 (STAT3) expression and 3′-untranslated region luciferase activity. Downregulation of miR-148a significantly increased STAT3 expression. Overexpression of STAT3 significantly inhibited the effect of miR-148a on cell viability and invasion potential. In conclusion, we found that miR-148a inhibited NSCLC cell proliferation and invasion potential through the inhibition of STAT3. Our findings highlight miR-148a/STAT3 axis as a novel therapeutic target for the inhibition of NSCLC growth.

Protease Serine S1 Family Member 8 (PRSS8) Inhibits Tumor Growth In Vitro and In Vivo in Human Non-Small Cell Lung Cancer

Protease serine S1 family member 8 (PRSS8), a membrane-anchored serine protease, has been reported to be involved in the development of several human cancers. However, the role of PRSS8 in non-small cell lung cancer (NSCLC) pathogenesis remains unclear. The objective of this study was to investigate PRSS8 expression, biological function, and its related molecular mechanism in NSCLC. Our results showed that PRSS8 was expressed in a low amount in NSCLC cell lines. Ectopic expression of PRSS8 inhibited tumor growth in vitro and in vivo. Furthermore, ectopic expression of PRSS8 inhibited the migration and invasion of NSCLC cells. It also suppressed the EMT process in A549 cells. Mechanistically, we found that the ectopic expression of PRSS8 downregulated the protein expression levels of p-JAK1, p-JAK2, and p-STAT3 in A549 cells. Taken together, our study showed that PRSS8 plays an important role in the growth and metastasis of NSCLC. Thus, PRSS8 may be a novel therapeutic target for NSCLC.

Physapubescin selectively induces apoptosis in VHL-null renal cell carcinoma cells through down-regulation of HIF-2α and inhibits tumor growth

We have purified physapubescin, a predominant steroidal lactone, from medicinal plant Physalis pubescens L., commonly named as "hairy groundcherry" in English and "Deng-Long-Cao" in Chinese. Von Hippel-Lindau (VHL)-null 786-O, RCC4 and A498 Renal Cell Carcinoma (RCC) cell lines expressing high levels of Hypoxia Inducible Factor (HIF)-2α are more sensitive to physapubescin-mediated apoptosis and growth inhibitory effect than VHL wild-type Caki-2 and ACHN RCC cell lines. Restoration of VHL in RCC4 cells attenuated the growth inhibitory effect of physapubescin. Physapubescin decreases the expression of HIF-2α and increases the expression of CCAAT/enhancer-binding protein homologus protein (CHOP), which leads to up-regulation of death receptor 5 (DR5), activation of caspase-8 and -3, cleavage of poly (ADP-Ribose) polymerase (PARP) and apoptosis. Under hypoxia conditions, the apoptotic and growth inhibitory effects of physapubescin are further enhanced. Additionally, physapubescin synergizes with TNF-related apoptosis-inducing ligand (TRAIL) for markedly enhanced induction of apoptosis in VHL-null 786-O cells but not in VHL wild-type Caki-2 cells. Physapubescin significantly inhibited in vivo angiogenesis in the 786-O xenograft. Physapubescin as a novel agent for elimination of VHL-null RCC cells via apoptosis is warranted for further investigation.