Physalin A induces apoptotic cell death and protective autophagy in HT1080 human fibrosarcoma cells

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.

Chemical components and against alzheimer's disease effects of the calyxes of Physalis alkekengi L. var. franchetii (Mast.) Makino

Physalis alkekengi L. var. franchetii (Mast.) Makino (PA), a traditional Chinese medicine, is utilised for treating dermatitis, sore throat, dysuria, and cough. This research aimed to identify the main constituents in the four extracted portions from the calyces of PA (PAC) utilising ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The Alzheimer's disease (AD) mice model was induced by D-galactose (D-gal) combined with aluminium chloride (AlCl3). Subsequent investigation into the underlying mechanisms involved behavioural and histopathological observations. The results demonstrated that four extracted portions of PAC (PACE) significantly enhanced memory and learning abilities in the Morris water maze. The concentrations of Aβ, tau and p-tau in brain tissue exhibited a significant decrease relative to the model group. Moreover, the four PACE treatment groups increased the glutathione (GSH) and superoxide dismutase (SOD) levels, while concurrently reducing malondialdehyde (MDA), interleukin-1β (IL-1β) and interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) levels. In summary, the current study demonstrates that the four PACE formulations exhibit beneficial anti-AD properties, with the most pronounced efficacy observed in the EA group. Additionally, PAC shows potential in mitigating neuroinflammation and oxidative damage by inhibiting the TLR4/NF-κB signalling pathway. This research lays a theoretical groundwork for the future clinical development and utilisation of PAC in treating AD.

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.

A comprehensive quality evaluation method of different medicinal parts of Physalis Calyx seu Fructus by fingerprints, chemometrics, antioxidant activity, network pharmacology and molecular docking

Physalis Calyx seu Fructus (PCF) is a herb widely used in China for its function of clearing heat and detoxifying, benefitting the pharynx and reducing phlegm, both in health care and in tea drinking. However, the quality of its fruit and calyx is uneven and the storage period is short. Therefore, it is crucial to develop other parts of PCF with longer storage periods and obvious medicinal effects. Firstly, high-performance liquid chromatography was used to develop the fingerprint of different parts of PCF, and various chemometric analyses were conducted to screen out chemical markers. The calyxes of PCF were found to cluster together, distinct from the fruits, roots, stems and leaves. The active components of PCF were concentrated in the persistent calyxes, and flavonoids were mainly found in the persistent calyxes and leaves. Secondly, the extraction of persistent calyxes showed the strongest scavenging ability of DPPH and ABTS. Finally, the important chemical markers were verified by network pharmacological analysis and molecular docking. It provides a reference for the clinical application of PCF, and the obtained chemical markers offer a scientific basis for quality evaluation.

Identification of P450 Candidates Associated with the Biosynthesis of Physalin-Class Compounds in Physalis angulata

The Physalis genus has long been used as traditional medicine in the treatment of various diseases. Physalins, the characteristic class of compounds in this genus, are major bioactive constituents. To date, the biogenesis of physalins remains largely unknown, except for the recently established knowledge that 24-methyldesmosterol is a precursor of physalin. To identify the genes encoding P450s that are putatively involved in converting 24-methyldesmosterol to physalins, a total of 306 P450-encoding unigenes were retrieved from our recently constructed P. angulata transcriptome. Extensive phylogenetic analysis proposed 21 P450s that might participate in physalin biosynthesis. To validate the candidates, we developed a virus-induced gene silencing (VIGS) system for P. angulata, and four P450 candidates were selected for the VIGS experiments. The reduction in the transcripts of the four P450 candidates by VIGS all led to decreased levels of physalin-class compounds in the P. angulata leaves. Thus, this study provides a number of P450 candidates that are likely associated with the biosynthesis of physalin-class compounds, forming a strong basis to reveal the unknown physalin biosynthetic pathway in the future.

Physalin A alleviates intervertebral disc degeneration via anti-inflammatory and anti-fibrotic effects

Background

The incidence of intervertebral disc degeneration (IVDD) is a common degenerative disease with inflammation, decreased autophagy, and progression of fibrosis as its possible pathogenesis. Physalin A (PA) is a widely studied anti-inflammatory drug. However, its therapeutic effects on IVDD remain unexplored. Therefore, we aimed to explore the therapeutic potential of PA in IVDD progression.

Materials and methods

In vivo, we investigated PA bioactivity using a puncture-induced IVDD rat model. IVDD signals and height changes were detected using X-ray, micro-CT, and MRI, and structural and molecular lesions using histological staining and immunohistochemistry of intervertebral disc sections. In vivo, interleukin-1 beta (IL-1β) and TGF-β1 were employed to establish inflammation fibrotic nucleus pulposus (NP) cells. The PA effect duration, concentration, influence pathways, and pathological changes in IVDD treatment were elucidated using western blotting, real-time PCR, and immunofluorescence.

Results

PA exerted significant effects on IVDD remission due to anti-inflammation, fibrosis reduction, and autophagy enhancement. In vitro, PA improved inflammation by blocking the NF-κB and MAPK pathways, whereas it promoted autophagy via the PI3K/AKT/mTOR pathway and affected fibrotic progression by regulating the SMAD2/3 pathway. Moreover, PA improved the disc degeneration process in IVDD model.

Conclusions

PA exhibited significant anti-inflammatory and anti-fibrotic effects and improved autophagy in vivo and in vitro IVDD models, thus effectively relieving IVDD progression, indicating it is a promising agent for IVDD treatment.

The translational potential of this article

This study successfully reveals that PA, a natural bioactive withanolide, effectively relieved IVDD progression via inflammation inhibition, fibrosis reduction, and autophagy enhancement, indicating it is a promising agent for IVDD treatment.

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.

Anti-inflammatory withanolides from the aerial parts of Physalis minima

Eight undescribed and two known withanolides were obtained from the aerial parts of Physalis minima. The structures of these compounds were defined by spectroscopic methods including 1D and 2D NMR, HRESIMS, and electronic circular dichroism (ECD) data analysis. Physminin E was elucidated to be a rare 13,14-seco-withanolide. Inhibitory effects of these compounds on nitric oxide (NO) production were evaluated by using LPS-activated RAW264.7 macrophages, and physminin C was shown to be the most active with an IC₅₀ value of 3.5 μM. The further mechanistic analysis of NO inhibition was performed by molecular docking and Western blotting.

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.

Physalin A Inhibits MAPK and NF-κB Signal Transduction Through Integrin αVβ3 and Exerts Chondroprotective Effect

Osteoarthritis (OA) is a common articular ailment presented with cartilage loss and destruction that is common observed in the elderly population. Physalin A (PA), a natural bioactive withanolide, exerts anti-inflammatory residences in more than a few diseases; however, little is known about its efficacy for OA treatment. Here, we explored the therapeutic effects and potential mechanism of PA in mouse OA. After the in vitro administration of PA, the expression of inflammation indicators including inducible nitric oxide synthase and cyclooxygenase-2 was low, indicating that PA could alleviate the IL-1β-induced chondrocyte inflammation response. Moreover, PA reduced IL-1β-induced destruction of the extracellular matrix by upregulating the gene expression of anabolism factors, including collagen II, aggrecan, and sry-box transcription factor 9, and downregulating the gene expression of catabolic factors, including thrombospondin motif 5 and matrix metalloproteinases. In addition, the chondroprotective effect of PA was credited to the inhibition of mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways. Furthermore, in vivo experiments showed that intra-articular injection of PA could alleviate cartilage destruction in a mouse OA model. However, the anti-inflammatory, anabolism enhancing, catabolism inhibiting, and MAPK and NF-κB signaling pathway inhibiting properties of PA on IL-1β-induced chondrocytes could be reversed when integrin αVβ3 is knocked down by siRNA. In conclusion, our work demonstrates that PA exhibits a chondroprotective effect that may be mediated by integrin αVβ3. Thus, PA or integrin αVβ3 might be a promising agent or molecular target for the treatment of OA.

Physalin A, 13,14-Seco-16, 24-Cyclo-Steroid, Inhibits Stemness of Breast Cancer Cells by Regulation of Hedgehog Signaling Pathway and Yes-Associated Protein 1 (YAP1)

The Hedgehog (HH) signaling pathway plays an important role in embryonic development and adult organ homeostasis. Aberrant activity of the Hedgehog signaling pathway induces many developmental disorders and cancers. Recent studies have investigated the relationship of this pathway with various cancers. GPCR-like protein Smoothened (SMO) and the glioma-associated oncogene (GLI1) are the main effectors of Hedgehog signaling. Physalin A, a bioactive substance derived from Physalis alkekengi, inhibits proliferation and migration of breast cancer cells and mammospheres formation. Physalin A-induced apoptosis and growth inhibition of mammospheres, and reduced transcripts of cancer stem cell (CSC) marker genes. Physalin A reduced protein expressions of SMO and GLI1/2. Down-regulation of SMO and GLI1 using siRNA inhibited mammosphere formation. Physalin A reduced mammosphere formation by reducing GLI1 gene expression. Down-regulation of GLI1 reduced CSC marker genes. Physalin A reduced protein level of YAP1. Down-regulation of YAP1 using siRNA inhibited mammosphere formation. Physalin A reduced mammosphere formation through reduction of YAP1 gene expression. Down-regulation of YAP1 reduced CSC marker genes. We showed that treatment of MDA-MB-231 breast cancer cells with GLI1 siRNA induced inhibition of mammosphere formation and down-regulation of YAP1, a Hippo pathway effector. These results show that Hippo signaling is regulated by the Hedgehog signaling pathway. Physalin A also inhibits the canonical Hedgehog and Hippo signaling pathways, CSC-specific genes, and the formation of mammospheres. These findings suggest that physalin A is a potential therapeutic agent for targeting CSCs.

Pharmacologic activities of phytosteroids in inflammatory diseases: Mechanism of action and therapeutic potentials

Natural products and their derivatives are known to be useful for treating numerous diseases since ancient times. Because of their high therapeutic potentials, the use of different medicinal plants is possible to treat varied inflammation-mediated chronic diseases. Among natural products, phytosteroids have emerged as promising compounds mostly because they have diverse pharmacological activities. Currently, available medications exert numerous systemic toxicities, including hypertension, immune suppression, osteoporosis, and metabolic abnormalities. Thus, further research on phytosteroids to subside these complications is of significant importance. In this study, the information on phytosteroids, their types, and actions against inflammation, and allergic complications was collected by a systematic survey of literature on several scientific search engines. The literature review suggested that phytosteroids exhibit antiinflammatory action via different modes through transrepression or selective COX-2 enzymes. Also, in silico ADMET analysis was carried out on available phytosteroids to uncover their pharmacokinetic properties. Our analysis has shown that eight compounds: withaferin A, stigmasterol, β-sitosterol, guggulsterone, diosgenin, sarsasapogenin, physalin A, and dioscin, -isolated from medicinal plants show similar pharmacokinetic properties as compared to dexamethasone, commercially available glucocorticoid. These phytosteroids could be useful for the treatment of inflammatory diseases, such as rheumatoid arthritis, inflammatory bowel diseases, multiple sclerosis, asthma, and cardiovascular diseases. Thus, systematic research is required to explore potent phytosteroids with lesser side effects, which might substitute the current medications.

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.

Cytotoxic Physalins from Aeroponically Grown Physalis acutifolia

Aeroponically grown Physalis acutifolia afforded five new and six known withanolides including 10 physalins. The structures of the new withanolides, acutifolactone (1), 5β,6β-epoxyphysalin C (2), 5α-chloro-6β-hydroxyphysalin C (3), and an inseparable mixture of 5β,6β-epoxy-2,3-dihydrophysalin F-3β-O-sulfate (4) and 5β,6β-epoxy-2,3-dihydrophysalin C-3β-O-sulfate (5), were elucidated by analysis of their spectroscopic data and chemical interconversions. The known withanolides were identified as physalins B (6), D (7), F (8), H (9), I (10), and U (11) by comparison of their spectroscopic data with those reported. Evaluation of 1-11 and the derivatives, 13 and 13a, obtained from 4 and 5 against a panel of four human cancer cell lines [NCI-H460 (non-small-cell lung), SF-268 (CNS glioma), PC-3 (prostate adenocarcinoma), and MCF-7 (breast adenocarcinoma)] and normal human lung fibroblast (WI-38) cells revealed that physalins 2, 3, 8, and 9 exhibited selective cytotoxic activity to at least one of the cancer cell lines tested compared to the normal cells and that 7, 10, and 11 were inactive up to a concentration of 10.0 μM. These data provided some preliminary structure-activity relationships and suggested that the mechanism of cytotoxic activity of physalins may differ from other classes of withanolides.

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.

Physalin D attenuates hepatic stellate cell activation and liver fibrosis by blocking TGF-β/Smad and YAP signaling

BACKGROUND

Hepatic fibrosis is considered integral to the progression of chronic liver diseases, as it leads to the development of cirrhosis and hepatocellular carcinoma. The activation of hepatic stellate cells (HSCs) is the dominant event in hepatic fibrogenesis. The transforming growth factor-β1 (TGF-β1) and Yes-associated protein (YAP) pathways play a pivotal role in HSC activation, hepatic fibrosis and cirrhosis progression. Therefore, targeting the TGF-β/Smad and YAP signaling pathways is a promising strategy for antifibrotic therapy.

PURPOSE

The present study investigated the protective effects of Physalin D (PD), a withanolide isolated from Physalis species (Solanaceae), against liver fibrosis and further elucidated the mechanisms involved in vitro and in vivo.

STUDY DESIGN/METHODS

We conducted a series of experiments using carbon tetrachloride (CCl₄)- and bile duct ligation (BDL)-induced fibrotic mice and cultured LX-2 cells. Serum markers of liver injury, and the morphology, histology and fibrosis of liver tissue were investigated. Western blot assays and quantitative real-time PCR were used to investigate the mechanisms underlying the antifibrotic effects of PD.

RESULT

PD decreased TGF-β1-induced COL1A1 promoter activity. PD inhibited TGF-β1-induced expression of Collagen I and α-smooth muscle actin (α-SMA) in human hepatic stellate LX-2 cells. PD significantly ameliorated hepatic injury, including transaminase activities, histology, collagen deposition and α-SMA, in CCl₄- or BDL-induced mice. Moreover, PD markedly decreased the expression of phosphorylated Smad2/3 in vitro and in vivo. Furthermore, PD significantly decreased YAP protein levels, and YAP knockdown did not further enhance the effects of PD, namely α-SMA inhibition, Collagen I expression and YAP target gene expression in LX-2 cells.

CONCLUSION

These results clearly show that PD ameliorated experimental liver fibrosis by inhibiting the TGF-β/Smad and YAP signaling pathways, indicating that PD has the potential to effectively treat liver fibrosis.

New cytotoxic withanolides from Physalis minima

Phytochemical investigation of Physalis minima led to the isolation of six new withanolides, including physaminilides HK (1-4), two artificial withanolides (5-6), and 19 known ones (7-25). Their structures were elucidated on the basis of spectroscopic analysis, including NMR and electronic circular dichroism (ECD) data. The isolates were evaluated for their cytotoxic activities against A375 human melanoma cells. Compounds 1, 8-9, 12-13, 15-17 and 19 exhibited significant cytotoxic activities with IC₅₀ values in the range of 1.2-7.5 μM.

Transcriptomic variation of the flower-fruit transition in Physalis and Solanum

Gene expression variations in response to fertilization between Physalis and Solanum might play essential roles in species divergence and fruit evolution. Fertilization triggers variation in fruit development and morphology. The Chinese lantern, a morphological novelty derived from the calyx, is formed upon fertilization in Physalis but is not observed in Solanum. The underlying genetic variations are largely unknown. Here, we documented the developmental and morphological differences in the flower and fruit between Physalis floridana and Solanum pimpinellifolium and then evaluated both the transcript sequence variation and gene expression at the transcriptomic level at fertilization between the two species. In Physalis transcriptomic analysis, 468 unigenes were identified as differentially expressed genes (DEGs) that were strongly regulated by fertilization across 3 years. In comparison with tomato, 14,536 strict single-copy orthologous gene pairs were identified between P. floridana and S. pimpinellifolium in the flower-fruit transcriptome. Nine types of gene variations with specific GO-enriched patterns were identified, covering 58.82% orthologous gene pairs that were DEGs in either trend or dosage at the flower-fruit transition between the two species, which could adequately distinguish Solanum and Physalis, implying that differential gene expression at fertilization might play essential roles during the divergence and fruit evolution of Solanum-Physalis. Virus-induced gene silencing analyses revealed the developmental roles of some transcription factor genes in fertility, Chinese lantern development, and fruit weight control in Physalis. This study presents the first floral transcriptomic resource of Physalis, and reveals some candidate genetic variations accounting for the early fruit developmental evolution in Physalis in comparison to Solanum.

Berberine represses human gastric cancer cell growth in vitro and in vivo by inducing cytostatic autophagy via inhibition of MAPK/mTOR/p70S6K and Akt signaling pathways

Berberine, an isoquinoline alkaloid from Coptidis Rhizoma, has been characterized as a potential anticancer drug due to its good anti-tumor effects. However, the molecular mechanisms involved in anti-gastric cancer remain poorly understood. Herein, the role of berberine in gastric cancer suppression by inducing cytostatic autophagy in vitro and in vivo was first investigated. Results showed that berberine induced an obvious growth inhibitory effect on gastric cancer BGC-823 cells without toxicity to human peripheral blood mononuclear cells. Treatment with berberine triggered cell autophagy, as demonstrated by the punctuate distribution of monodansylcadaverine staining and GFP-LC3, as well as the LC3-II, Beclin-1 and p-ULK1 promotion, and p62 degradation. Inhibition of autophagy by 3-MA, CQ, Baf-A1 and BECN1 siRNA obviously increased cell viability of berberine-exposed gastric cancer cells, which confirmed the anti-cancer role of autophagy induced by berberine. Mechanistic studies showed that berberine inhibited mTOR, Akt and MAPK (ERK, JNK and p38) pathways thereby inducing autophagy. Inhibition of above pathways increases berberine induced autophagy and cytotoxicity. Interestingly, mTOR/p70S6K was inhibited by the MAPK but not Akt. Furthermore, inhibition of autophagy reversed berberine down-regulated mTOR, Akt and MAPK. In xenografts, the berberine induced autophagy leads to suppression of tumor proliferation with no side-effect, and western blotting displayed an apparent attenuation of p-mTOR, p-p70S6K, p-Akt, p-ERK, p-JNK and p-p38 in tumors from berberine treated mice. Briefly, these results indicated that berberine repressed human gastric cancer cell growth in vitro and in vivo by inducing cytostatic autophagy via inhibition of MAPK/mTOR/p70S6K and Akt, and provided a molecular basis for the treatment of gastric cancer.

New withanolides from Physalis minima and their cytotoxicity against A375 human melanoma cells

The new withanolides physaminilide A–G (1–7), and two artificial withanolides (8–9) were isolated from Physalis minima. Compounds 2, 5 and 8 exhibited significant cytotoxicity towards human tumor cells.

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.

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.

Daphnegiravone D from Daphne giraldii Nitsche induces p38-dependent apoptosis via oxidative and nitrosative stress in hepatocellular carcinoma cells

Daphnegiravone D (DGD), a prenylated flavonoid from Daphne giraldii Nitsche, significantly inhibited cell growth of several cancer cell lines without cytotoxicity on human normal cells. Our previous study showed that DGD could induce apoptosis in hepatocellular carcinoma Hep3B and HepG2 cells, but the detailed mechanism was still unclear. The present study provides that DGD-induced oxidative and nitrosative stress contribute to apoptotic cell death in Hep3B and HepG2 cells. Furthermore, there is a positive loop between oxidative stress and p38 activation, similar result is observed between nitrosative stress and p38. N-Acetylcysteine (NAC), a reactive oxygen species scavenger, could relieve DGD-induced oxidative stress, but exerts little effect on nitrosative stress. In addition, carboxy-PTIO (PTIO, a well-known scavenger of reactive nitrogen species) down-regulates the induction of nitrosative stress without obvious effect on oxidative stress in DGD-treated cells. In conclusion, the induction of oxidative and nitrosative stress could enhance p38-mediated apoptosis in DGD-treated Hep3B and HepG2 cells. Moreover, we speculated that OS and NS could not ultimately affect each other in DGD-treated HCC cells. This study gives a new insight on the mechanism of DGD-induced apoptotic cell death via oxidative and nitrosative stress in HCC cells.

Design and synthesis of new antitumor agents with the 1,7-epoxycyclononane framework. Study of their anticancer action mechanism by a model compound

This article describes the design, synthesis and biological evaluation of a new family of antitumor agents having the 1,7-epoxycyclononane framework. We have developed a versatile synthetic methodology that allows the preparation of a chemical library with structural diversity and in good yield. The synthetic methodology has been scaled up to the multigram level and can be developed in an enantioselective fashion. The study in vitro of a model compound, in front of the cancer cell lines HL-60 and MCF-7, showed a growth inhibitory effect better than that of cisplatin. The observation of cancer cells by fluorescence microscopy showed the presence of apoptotic bodies and a degradation of microtubules. The study of cell cycle and mechanism of death of cancer cells by flow cytometry indicates that the cell cycle arrested at the G₀/G₁ phase and that the cells died by apoptosis preferably over necrosis. A high percentage of apoptotic cells at the subG₀/G₁ level was observed. This indicates that our model compound does not behave as an antimitotic agent like nocodazole, used as a reference, which arrests the cell cycle at G₂/M phase. The interaction of anticancer agents with DNA molecules was evaluated by atomic force microscopy, circular dichroism and electrophoresis on agarose gel. The results indicate that the model compound has not DNA as a target molecule. The in silico study of the model compound showed a potential good oral bioavailability.

Autophagy-dependent apoptosis is triggered by a semi-synthetic [6]-gingerol analogue in triple negative breast cancer cells

Triple negative breast cancer (TNBC) is very aggressive and lacks specific therapeutic targets, having limited treatment options and poor prognosis. [6]-gingerol is the most abundant and studied compound in ginger, presenting diverse biological properties such as antitumor activity against several types of cancer, including breast cancer. In this study, we show that the semi-synthetic analogue SSi6, generated after chemical modification of the [6]-gingerol molecule, using acetone-2,4-dinitrophenylhydrazone (2,4-DNPH) reagent, enhanced selective cytotoxic effects on MDA-MB-231 cells. Remarkably, unlike the original [6]-gingerol molecule, SSi6 enabled autophagy followed by caspase-independent apoptosis in tumor cells. We found a time-dependent association between SSi6-induced oxidative stress, autophagy and apoptosis. Initial SSi6-induced reactive oxygen species (ROS) accumulation (1h) led to autophagy activation (2-6h), which was followed by caspase-independent apoptosis (14h) in TNBC cells. Additionally, our data showed that SSi6 induction of ROS plays a key role in the promotion of autophagy and apoptosis. In order to investigate whether the observed cell death induction was dependent on preceding autophagy in MDA-MB-231 cells, we used siRNA to knock down LC3B prior to SSi6 treatment. Our data show that LC3B downregulation decreased the number of apoptotic cells after treatment with SSi6, indicating that autophagy is a key initial step on SSi6-induced caspase-independent apoptosis. Overall, the results of this study show that structural modifications of natural compounds can be an interesting strategy for developing antitumor drugs, with distinct mechanisms of actions, which could possibly be used against triple negative breast cancer cells that are resistant to canonical apoptosis-inducing drugs.

Involvement of estrogen receptors in silibinin protection of pancreatic β-cells from TNFα- or IL-1β-induced cytotoxicity

Silibinin is a polyphenolic flavonoid that exhibits anticarcinogenic, anti-inflammatory and cytoprotective effects. The effect of silibinin on pancreatic islet β-cell is yet largely unknown in spite of well documented-hepatoprotective effects. Protecting the functional insulin-producing β-cells in the pancreas is a major therapeutic challenge in the patients with type 1 (T1DM) or type 2 diabetes mellitus (T2DM). This study reports the effect of silibinin on the rat pancreatic β-cell line, INS-1, damaged with pro-inflammatory cytokine, TNFα or IL-1β. Exposure to TNFα or IL-1β for 48 h caused INS-1 cells to reduce the production of insulin as well as cell viability. These actions of TNFα or IL-1β are associated with suppression of the expression of estrogen receptors (ERs). Further study revealed that silibinin protected the suppression in the expression of both ERα and ERβ that were involved in insulin synthesis and release, respectively. Furthermore, evidence is obtained that silibinin may impede the loss of critical INS-1 cells by promoting autophagy and preventing apoptosis. Direct cytoprotective effects of silibinin on INS-1 cells suggest that silibinin may be therapeutically beneficial for diabetes.

Synthesis of the 10-oxabicyclo[5.2.1]decane framework present in bioactive natural products

The present work deals with the synthesis of the 10-oxabicyclo[5.2.1]decane framework present in bioactive natural products like physalins, with potential as antitumor agents. This synthetic methodology involves several key reactions: (a) synthesis of polyfunctionalized cycloheptenones by [4 + 3] cycloaddition reactions of furan precursors with oxyallyl cations; (b) Nicholas reaction with propargyl cations stabilized as dicobalt hexacarbonyl complexes; (c) demetallation and hydration of the resulting acetylenes; (d) stereoconvergent aldol cyclization to generate a key oxatricyclic intermediate and (e) a β-fragmentation process that affords, under hypoiodite photolysis, the desired product with moderate to good yield. The final compounds are the result of a radicalary β-fragmentation at the level of C2-C6 with respect to the tertiary hydroxyl group on C6, with an unexpected contraction from a ten- to a nine-membered ring system, via a radical addition to the carbonyl group on C4. The synthetic methodology has been scaled up to multigram level with good overall yield. Further biological, biochemical and biophysical studies are being carried out in our laboratory on these 1,7-epoxycyclononane derivatives to determine the potential of this kind of oxabicyclic compound as future hits and/or leads for the development of new anticancer drugs. The preliminary evaluation of the anticancer activity of the representative synthesized compounds, against the leukaemia cancer cell lines K-562 and SR, shows a promising activity with a GI₅₀ = 0.01 μM and a LC₅₀ = 7.4 μM for a conveniently functionalized 10-oxabicyclo[5.2.1]decane.

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.

Physalins V-IX, 16,24-cyclo-13,14-seco withanolides from Physalis angulata and their antiproliferative and anti-inflammatory activities

Five new physalins, including a novel 1,10-seco one, physalin V (1), a tricarboxylic acid cycle one, physalin VIII (5), a rare 11,15-cyclo one, physalin IX (6), and two new ones, physalins VI (2) and VII (4) were isolated from stems and leaves of Physalis angulata together with eleven known analogues (3 and 7–16). Their structures were established by MS, IR, UV, and NMR spectroscopic analysis, together with the X-ray diffraction analysis of neophysalin, physalin P (12), and the structure of physalin D₁ (3) has been revised here. These isolated compounds were evaluated for their antiproliferative activities against human cancer cells (C4-2B, 22Rv1, 786-O, A-498, ACHN, and A375-S2) and inhibitory effects on nitric oxide production. Compounds 9 and 10 showed antiproliferative activities against all tested human cancer cells with IC₅₀ values of 0.24–3.17 μM. Compounds 1, 3, 4, 9, 10, 13, 14, and 16 exhibited inhibitory activities against NO production. The IC₅₀ values of compounds 9, 10, 13, and 16 were between 0.32 and 4.03 μM, while compounds 1, 3, 4, and 14 had IC₅₀ values of 12.83–34.19 μM. Herein, plausible biosynthetic pathways for rare structures 1 and 6 and structure−activity relationships on the inhibition of NO production for all isolated compounds are discussed.

Autophagy as a potential target for sarcoma treatment

Autophagy is a constitutively active, evolutionary conserved, catabolic process for maintaining homeostasis in cellular stress responses and cell survival. Although its mechanism has not been fully illustrated, recent work on autophagy in various types of sarcomas has demonstrated that autophagy exerts an important role in sarcoma cell growth and proliferation, in pro-survival response to therapies and stresses, and in therapeutic resistance of sarcoma. Thus, the autophagic process is being seen as a possibly novel therapeutic target of sarcoma. Additionally, some co-regulators of autophagy have also been investigated as promising biomarkers for the diagnosis and prognosis of sarcoma. In this review, we summarize contemporary advances in the role of autophagy in sarcoma and discuss the potential of autophagy as a new target for sarcoma treatment.

Importance of ROS-mediated autophagy in determining apoptotic cell death induced by physapubescin B

Physapubescin B, a steroidal compound extracted from the plant Physalis pubescens L. (Solanaceae), has been reported to possess anti-cancer potential, whereas the molecular mechanism remains elusive. In this study, we first demonstrated that physapubescin B induced autophagy in human cancer cells based on the evidence that physapubescin B increased lipidation of microtubule-associated protein 1 light chain 3 (LC3) as well as number of GFP-LC3 puncta. We further examined the molecular mechanisms and found that physapubescin B enhanced the autophagic flux through promotion of reactive oxygen species (ROS)-mediated suppression of mammalian target of rapamycin complex I (mTORC1), the key negative regulator of autophagy. Additionally, excessive ROS caused by physapubescin B also induced p53-dependent apoptotic cell death. Furthermore, we provided evidence that inhibition of autophagy either by a chemical inhibitor or gene silencing promoted physapubescin B-induced apoptotic cell death, indicating that autophagy serves as a cell survival mechanism to protect cell death. Thus, our data provide a clue that inhibition of autophagy would serve as a novel strategy for enhancing the anti-cancer potential of physapubescin B.

Two sulfonate metabolites of physalin A in rats

1. Physalin A is a bioactive withanolide isolated from the natural plant Physalis alkekengi var. franchetii (Solanaceae), a common traditional Chinese herbal medicine. This study aims to investigate the metabolites of physalin A in vivo. 2. Two metabolites (M1 and M2) were characterized as sulfonate metabolites in the feces obtained from rats treated with physalin A orally at a dose of 15 mg/kg/day for 3 days, by application of a UPLC-Q/TOF-MS method. Furthermore, formation of the two sulfonate metabolites was verified by chemical synthesis and NMR, including ¹H NMR, ¹³C NMR and two-dimensional NMR. The structures of M1 and M2 were identified to be 3α-sulfo-2,25β,27-trihydrophysalin A and 3α,27-disulfo-2,25α-dihydrophysalin A, respectively. 3. In summary, this study indicated that physalin A could be biotransformed to sulfonate metabolites with strong polarity, which contributed to the elimination of physalin A. A rare metabolic pathway has been revealed in this study.

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

The signal transducers and activators of transcription 3 (STAT3) signaling pathway plays critical roles in the pathogenesis and progression of various human cancers, including non-small cell lung cancer (NSCLC). In this study, we aimed to evaluate the therapeutic potential of physalin A, a bioactive withanolide derived from Physalis alkekengi var. francheti used in traditional Chinese medicine, was evaluated in human NSCLC cells. Its and determined whether it effect oninhibited both constitutive and induced STAT3 activity, through repressing the phosphorylation levels of JAK2 and JAK3, resulting in anti-proliferation and pro-apoptotic effects on NSCLC cells was also determined, and. theThe antitumor effects of physalin A were also validated usingin an in vivo mouse xenograft models of NSCLC cells. Physalin A had anti-proliferative and pro-apoptotic effects in NSCLC cells with constitutively activated STAT3; it also suppressed both constitutive and induced STAT3 activity by modulating the phosphorylation of JAK2 and JAK3. Furthermore, physalin A abrogated the nuclear translocation and transcriptional activity of STAT3, thereby decreasing the expression levels of STAT3, its target genes, such as Bcl-2 and XIAP. Knockdown of STAT3 expression by small interfering RNA (siRNA) significantly enhanced the pro-apoptotic effects of physalin A in NSCLC cells. Moreover, physalin A significantly suppressed tumor xenograft growth. Thus, as an inhibitor of JAK2/3-STAT3 signaling, physalin A, has potent anti-tumor activities, which may facilitate the development of a therapeutic strategy for treating NSCLC.

A novel withanolide with an unprecedented carbon skeleton from Physalis angulata

Aromaphysalin A (1), possessing an exceptional C(11)–C(15) bond and a rearranged 4,9-cyclized aromatic ring, is isolated from of Physalis angulata.

Unprecedented 22,26-seco physalins from Physalis angulata and their anti-inflammatory potential

Aromaphysalin B (2), as a first 11,15-cyclo-9(10),14(17),22(26)-triseco physalin with an unprecedented aromatic ring, was isolated from Physalis angulata.

Withanolides from the stems and leaves of Physalis pubescens and their cytotoxic activity

A phytochemical study of Physalis pubescens L. afforded twelve compounds, including six new withanolides (1, 4, and 6i-9), four new withanolide glucosides (2, 3, 5, and 6), and two known withanolides (10 and 11). Their structures were established via extensive spectroscopic analysis. The absolute configuration of 3 was assigned using X-ray crystallography, and the absolute configurations of the 1,2-diol moiety in 1 were determined using the in situ dimolybdenum electronic circular dichroism method. Compounds 7, 9, and 10 exhibited significant cytotoxicity against human prostate cancer cells (C4-2B and 22Rvl), human renal carcinoma cells (786-O, A-498, Caki-2, and ACHN), human melanoma cells (A375 and A375-S2), and human normal hepatic cell line (L02) with IC₅₀ values in the range of 0.17-5.30μM.

Antiproliferative and Anti-inflammatory Withanolides from Physalis angulata

Sixteen new withanolides, physangulatins A-N (1-14) and withaphysalins Y and Z (15 and 16), as well as 12 known analogues, were isolated from the stems and leaves of Physalis angulata L. Their structures were established using extensive spectroscopic data analyses. The absolute configurations of 1 and 9 were assigned via X-ray crystallography. The isolated compounds were tested for their antiproliferative effects against human prostate cancer cells (C4-2B and 22Rvl), human renal carcinoma cells (786-O, A-498, and ACHN), and human melanoma cells (A375-S2), as well as inhibitory effects on NO production induced by LPS in macrophages. Compounds 9, 17, 20, 21, 25, and 27 showed antiproliferative effects against all tested cancer cells, with IC50 values of 0.18-7.43 μM. Compounds 3-5, 9-11, 17, 20-22, 24, 25, and 27 displayed inhibitory effects against NO production, with IC50 values of 1.36-11.59 μM.

Physalin A induces G2/M phase cell cycle arrest in human non-small cell lung cancer cells: involvement of the p38 MAPK/ROS pathway

Physalin A (PA) is an active withanolide isolated from Physalis alkekengi var. franchetii, a traditional Chinese herbal medicine named Jindenglong, which has long been used for the treatment of sore throat, hepatitis, and tumors in China. In the present study, we firstly investigated the effects of PA on proliferation and cell cycle distribution of the human non-small cell lung cancer (NSCLC) A549 cell line, and the potential mechanisms involved. Here, PA inhibited cell growth in dose- and time-dependent manners. Treatment of A549 cells with 28.4 μM PA for 24 h resulted in approximately 50 % cell death. PA increased the amount of intracellular ROS and the proportion of cells in G2/M. G2/M arrest was attenuated by the addition of ROS scavenger NAC. ERK and P38 were triggered by PA through phosphorylation in a time-dependent manner. The phosphorylation of ERK and P38 were not attenuated by the addition of NAC, but the use of the p38 inhibitor could reduce, at least in part, PA-induced ROS and the proportion of cells in G2/M. PA induces G2/M cell cycle arrest in A549 cells involving in the p38 MAPK/ROS pathway. This study suggests that PA might be a promising therapeutic agent against NSCLC.

A potent betulinic acid analogue ascertains an antagonistic mechanism between autophagy and proteasomal degradation pathway in HT-29 cells

Background

Betulinic acid (BA), a member of pentacyclic triterpenes has shown important biological activities like anti-bacterial, anti-malarial, anti-inflammatory and most interestingly anticancer property. To overcome its poor aqueous solubility and low bioavailability, structural modifications of its functional groups are made to generate novel lead(s) having better efficacy and less toxicity than the parent compound. BA analogue, 2c was found most potent inhibitor of colon cancer cell line, HT-29 cells with IC₅₀ value 14.9 μM which is significantly lower than standard drug 5-fluorouracil as well as parent compound, Betulinic acid. We have studied another mode of PCD, autophagy which is one of the important constituent of cellular catabolic system as well as we also studied proteasomal degradation pathway to investigate whole catabolic pathway after exploration of 2c on HT-29 cells.

Methods

Mechanism of autophagic cell death was studied using fluorescent dye like acridine orange (AO) and monodansylcadaverin (MDC) staining by using fluorescence microscopy. Various autophagic protein expression levels were determined by Western Blotting, qRT-PCR and Immunostaining. Confocal Laser Scanning Microscopy (CLSM) was used to study the colocalization of various autophagic proteins. These were accompanied by formation of autophagic vacuoles as revealed by FACS and transmission electron microscopy (TEM). Proteasomal degradation pathway was studied by proteasome-Glo™ assay systems using luminometer.

Results

The formation of autophagic vacuoles in HT-29 cells after 2c treatment was determined by fluorescence staining – confirming the occurrence of autophagy. In addition, 2c was found to alter expression levels of different autophagic proteins like Beclin-1, Atg 5, Atg 7, Atg 5-Atg 12, LC3B and autophagic adapter protein, p62. Furthermore we found the formation of autophagolysosome by colocalization of LAMP-1 with LC3B, LC3B with Lysosome, p62 with lysosome. Finally, as proteasomal degradation pathway downregulated after 2c treatment colocalization of ubiquitin with lysosome and LC3B with p62 was studied to confirm that protein degradation in autophagy induced HT-29 cells follows autolysosomal pathway.

Conclusions

In summary, betulinic acid analogue, 2c was able to induce autophagy in HT-29 cells and as proteasomal degradation pathway downregulated after 2c treatment so protein degradation in autophagy induced HT-29 cells follows autolysosomal pathway.