A Review on Phytochemistry and Pharmacology of Cortex Periplocae

Mechanism of XiJiaQi in the treatment of chronic heart failure: Integrated analysis by pharmacoinformatics, molecular dynamics simulation, and SPR validation

OBJECTIVE

Chronic heart failure (CHF) is a complicated clinical syndrome with a high mortality rate. XiJiaQi (XJQ) is a traditional Chinese medicine used in the clinical treatment of CHF, but its bioactive components and their modes of action remain unknown. This study was designed to unravel the molecular mechanism of XJQ in the treatment of CHF using multiple computer-assisted and experimental methods.

METHODS

Pharmacoinformatics-based methods were used to explore the active components and targets of XJQ in the treatment of CHF. ADMETlab was then utilized to evaluate the pharmacokinetic and toxicological properties of core components. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were to explore the underlying mechanism of XJQ treatment. Molecular docking, surface plasmon resonance (SPR), and molecular dynamics (MD) were employed to evaluate the binding of active components to putative targets.

RESULTS

Astragaloside IV, formononetin, kirenol, darutoside, periplocin and periplocymarin were identified as core XJQ-related components, and IL6 and STAT3 were identified as core XJQ targets. ADME/T results indicated that periplocin and periplocymarin may have potential toxicity. GO and KEGG pathway analyses revealed that XJQ mainly intervenes in inflammation, apoptosis, diabetes, and atherosclerosis-related biological pathways. Molecular docking and SPR revealed that formononetin had a high affinity with IL6 and STAT3. Furthermore, MD simulation confirmed that formononetin could firmly bind to the site 2 region of IL6 and the DNA binding domain of STAT3.

CONCLUSION

This study provides a mechanistic rationale for the clinical application of XJQ. Modulation of STAT3 and IL-6 by XJQ can impact CHF, further guiding research efforts into the molecular underpinnings of CHF.

Periplocin inhibits hepatocellular carcinoma progression and reduces the recruitment of MDSCs through AKT/NF-κB pathway

AIMS

We aimed to evaluate the effect of periplocin on inhibiting hepatocellular carcinoma (HCC) and further determine its mechanisms.

MAIN METHODS

Cytotoxic activity of periplocin against HCC cells was tested by CCK-8 and colony formation assays. The antitumor effects of periplocin were evaluated in human HCC SK-HEP-1 xenograft and murine HCC Hepa 1-6 allograft mouse models. Flow cytometry was used to measure cell cycle distribution, apopotosis, and the number of myeloid-derived suppressor cells (MDSCs). Hoechst 33258 dye was applied to observe the nuclear morphology. Network pharmacology was performed to predict possible signaling pathways. Drug affinity responsive target stability assay (DARTS) was used to evaluate AKT binding of periplocin. Western blotting, immunohistochemistry, and immunofluorescence were used to examine the protein expression levels.

KEY FINDING

Periplocin inhibited cell viability with IC₅₀ values from 50 nM to 300 nM in human HCC cells. Periplocin disrupted cell cycle distribution and promoted cell apoptosis. Moreover, AKT was predicted as the target of periplocin by network pharmacology, which was confirmed by that AKT/NF-κB signaling was inhibited in periplocin-treated HCC cells. Periplocin also inhibited the expression of CXCL1 and CXCL3, leading to decreased accumulation of MDSCs in HCC tumors.

SIGNIFICANCE

These findings reveal the function of periplocin in inhibiting HCC progression by G₂/M arrest, apoptosis and suppression of MDSCs accumulation through blockade of the AKT/NF-κB pathway. Our study further suggests that periplocin has the potential to be developed as an effective therapeutic agent for HCC.

Periplocin targets low density lipoprotein receptor-related protein 4 to attenuate osteoclastogenesis and protect against osteoporosis

Osteoporosis is a common inflammaging-related condition, where long-term accumulation of pro-inflammatory cytokines causes massive bone loss. Periplocin, a cardiotonic steroid isolated from Periploca forrestii, has been proved to reduce inflammation in several inflammatory diseases, such as rheumatoid arthritis. However, its effect and mechanism of inflammation in osteoporosis, in which pro-inflammatory factors accelerate bone loss, has not been well demonstrated. In this study, periplocin attenuated receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation of bone marrow-derived macrophages (BMMs) and RAW264.7 cells in vitro. It reduced osteoclast numbers and bone resorption in a concentration- and time-dependent manner. Further, periplocin treatment resulted in reduced bone loss on mice with ovariectomy-induced osteoporosis in vivo. By transcriptome sequencing, periplocin was indicated to function through inhibition of the mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways and attenuating interactions between NF-κB and nuclear factor of activated T-cells 1 (NFATc1). It was further detected to bind low density lipoprotein receptor-related protein 4 (LRP4) in osteoclasts to exert anti-inflammatory and anti-osteoclastic effects. Overall, the findings have highlighted a better understanding for the anti-inflammatory and anti-osteoclastic role of periplocin in osteoporosis and its mechanism, bringing new possibilities for osteoporosis treatment.

Dual targets of lethal apoptosis and protective autophagy in liver cancer with periplocymarin elicit a limited therapeutic effect

Cardiac glycosides (CGs) are candidate anticancer agents that function by increasing [Ca²⁺]i to induce apoptotic cell death in several types of cancer cells. However, new findings have shown that the anti‑cancer effects of CGs involve complex cell‑signal transduction mechanisms. Hence, exploring the potential mechanisms of action of CGs may provide insight into their anti‑cancer effects and thus aid in the selection of the appropriate CG. Periplocymarin (PPM), which is a cardiac glycoside, is an active ingredient extracted from Cortex periplocae. The role of PPM was evaluated in HepG2 cells and xenografted nude mice. Cell proliferation, real‑time ATP rate assays, western blotting, cell apoptosis assays, short interfering RNA transfection, the patch clamp technique, electron microscopy, JC‑1 staining, immunofluorescence staining and autophagic flux assays were performed to evaluate the function and regulatory mechanisms of PPM in vitro. The in vivo activity of the PPM was assessed using a mouse xenograft model. The present study demonstrated that PPM synchronously activated lethal apoptosis and protective autophagy in liver cancer, and the initiation of autophagy counteracted the inherent pro‑apoptotic capacity and impaired the anti‑cancer effects. Specifically, PPM exerted a pro‑-apoptotic effect in HepG2 cells and activated macroautophagy by initiation of the AMPK/ULK1 and mTOR signaling pathways. Activation of macroautophagy counteracted the pro‑apoptotic effects of PPM, but when it was combined with an autophagy inhibitor, the anti‑cancer effects of PPM in mice bearing HepG2 xenografts were observed. Collectively, these results indicated that a self‑limiting effect impaired the pro‑apoptotic effects of PPM in liver cancer, but when combined with an autophagy inhibitor, it may serve as a novel therapeutic option for the management of liver cancer.

Analyzing the Systems Biology Effects of COVID-19 mRNA Vaccines to Assess Their Safety and Putative Side Effects

COVID-19 vaccines have been instrumental tools in reducing the impact of SARS-CoV-2 infections around the world by preventing 80% to 90% of hospitalizations and deaths from reinfection, in addition to preventing 40% to 65% of symptomatic illnesses. However, the simultaneous large-scale vaccination of the global population will indubitably unveil heterogeneity in immune responses as well as in the propensity to developing post-vaccine adverse events, especially in vulnerable individuals. Herein, we applied a systems biology workflow, integrating vaccine transcriptional signatures with chemogenomics, to study the pharmacological effects of mRNA vaccines. First, we derived transcriptional signatures and predicted their biological effects using pathway enrichment and network approaches. Second, we queried the Connectivity Map (CMap) to prioritize adverse events hypotheses. Finally, we accepted higher-confidence hypotheses that have been predicted by independent approaches. Our results reveal that the mRNA-based BNT162b2 vaccine affects immune response pathways related to interferon and cytokine signaling, which should lead to vaccine success, but may also result in some adverse events. Our results emphasize the effects of BNT162b2 on calcium homeostasis, which could be contributing to some frequently encountered adverse events related to mRNA vaccines. Notably, cardiac side effects were signaled in the CMap query results. In summary, our approach has identified mechanisms underlying both the expected protective effects of vaccination as well as possible post-vaccine adverse effects. Our study illustrates the power of systems biology approaches in improving our understanding of the comprehensive biological response to vaccination against COVID-19.

Periplocymarin Induced Colorectal Cancer Cells Apoptosis Via Impairing PI3K/AKT Pathway

Colorectal cancer (CRC) is one of the most common cancers worldwide, and approximately one-third of CRC patients present with metastatic disease. Periplocymarin (PPM), a cardiac glycoside isolated from Periploca sepium, is a latent anticancer compound. The purpose of this study was to explore the effect of PPM on CRC cells. CRC cells were treated with PPM and cell viability was evaluated by CCK-8 assay. Flow cytometry and TUNEL staining were performed to assess cell cycle and apoptosis. Quantitative proteomics has been used to check the proteins differentially expressed by using tandem mass tag (TMT) labeling and liquid chromatography–tandem mass spectrometry. Bioinformatic analysis was undertaken to identify the biological processes that these differentially expressed proteins are involved in. Gene expression was analyzed by western blotting. The effect of PPM in vivo was primarily checked in a subcutaneous xenograft mouse model of CRC, and the gene expression of tumor was checked by histochemistry staining. PPM could inhibit the proliferation of CRC cells in a dose-dependent manner, induce cell apoptosis and promote G0/G1 cell cycle arrest. A total of 539 proteins were identified differentially expressed following PPM treatment, where among those there were 286 genes upregulated and 293 downregulated. PPM treatment caused a pro-apoptosis gene expression profile both in vivo and in vitro, and impaired PI3K/AKT signaling pathway might be involved. In addition, PPM treatment caused less detrimental effects on blood cell, hepatic and renal function in mice, and the anti-cancer effect was found exaggerated by PPM+5-FU combination treatment. PPM may perform anti-CRC effects by promoting cell apoptosis and this might be achieved by targeting PI3K/AKT pathway. PPM might be a safe and promising anti-cancer drug that needs to be further studied.

Simultaneous determination of periplocin, periplocymarin, periplogenin, periplocoside M and periplocoside N of Cortex Periplocae in rat plasma and its application to a pharmacokinetic study

A sensitive and specific ultra-performance liquid chromatographic-tandem mass spectrometric method was developed and validated to simultaneously determine periplocin, periplocymarin (PM), periplogenin (PG), periplocoside M (PSM) and periplocoside N (PSN) in rat plasma. Acetonitrile was employed to precipitate plasma with appropriate sensitivity and acceptable matrix effects. Chromatographic separation was performed using a Waters HSS T3 column with a gradient elution using water and acetonitrile both containing 0.1% formic acid and 0.1 mm ammonium formate within 8 min. Detection was performed in positive ionization mode using multiple reaction monitoring. The method was fully validated in terms of selectivity, linearity, accuracy, precision, recovery, matrix effects and stability. Using this method, the concentrations of periplocin, PM, PG, PSM and PSN were established after oral administration of Cortex Periplocae extract to rats, and the pharmacokinetic characteristics of periplocin, PM, PG, PSM and PSN were assessed. Generally, PM, PG, PSM and PSN were eliminated slowly and their half-lives were all >8 h. In addition, the systemic exposure of PSM showed significant differences between genders with more than 10 times higher area under the concentration-time curve in female rats than in male rats. The findings of this study provide useful information for further research on Cortex Periplocae.

Periplocin and cardiac glycosides suppress the unfolded protein response

The unfolded protein response (UPR) controls protein homeostasis through transcriptional and translational regulation. However, dysregulated UPR signaling has been associated with the pathogenesis of many human diseases. Therefore, the compounds modulating UPR may provide molecular insights for these pathologies in the context of UPR. Here, we screened small-molecule compounds that suppress UPR, using a library of Myanmar wild plant extracts. The screening system to track X-box binding protein 1 (XBP1) splicing activity revealed that the ethanol extract of the Periploca calophylla stem inhibited the inositol-requiring enzyme 1 (IRE1)-XBP1 pathway. We isolated and identified periplocin as a potent inhibitor of the IRE1-XBP1 axis. Periplocin also suppressed other UPR axes, protein kinase R-like endoplasmic reticulum kinase (PERK), and activating transcription factor 6 (ATF6). Examining the structure–activity relationship of periplocin revealed that cardiac glycosides also inhibited UPR. Moreover, periplocin suppressed the constitutive activation of XBP1 and exerted cytotoxic effects in the human multiple myeloma cell lines, AMO1 and RPMI8226. These results reveal a novel suppressive effect of periplocin or the other cardiac glycosides on UPR regulation, suggesting that these compounds will contribute to our understanding of the pathological or physiological importance of UPR.

Discovery of potential Q-marker of traditional Chinese medicine based on plant metabolomics and network pharmacology: Periplocae Cortex as an example

BACKGROUND

Quality control exerted great importance on the clinical application of drugs for ensuring effectiveness and safety. Due to chemical complexity, diversity among different producing areas and harvest seasons, as well as unintentionally mixed with non-medicinal parts, the current quality standards of traditional Chinese medicine (TCM) still faced challenges in evaluating the overall chemical consistency.

PURPOSE

We aimed to develop a new strategy to discover potential quality marker (Q-marker) of TCM by integrating plant metabolomics and network pharmacology, using Periplocae Cortex (GP, the dried root bark of Periploca sepium Bge.) as an example.

METHODS

First, plant metabolomics analysis was performed by UPLC/Q-TOF MS in 89 batches of samples to discover chemical markers to distinguish medicinal parts (GP) and non-medicinal parts (the dried stem bark of Periploca sepium Bge. (JP)), harvest seasons and producing region of Periplocae Cortex. Second, network pharmacology was applied to explore the initial linkages among chemical constituents, targets and diseases. Last, potential Q-marker were selected by integrating analysis of plant metabolomics and network pharmacology, and the quantification method of Q-marker was developed by using UPLC-TQ-MS.

RESULTS

The chemical profiling of GP and JP was investigated. Fifteen distinguishing features were designated as core chemical markers to distinguish GP and JP. Besides, the content of 4-methoxybenzaldehyde-2-O-β-d-xylopyranosyl-(1→6)-β-d-glucopyranoside could be used to identify Periplocae Cortex harvested in spring-autumn or summer. Meanwhile, a total of 15 components targeted rheumatoid arthritis were screened out based on network pharmacology. Taking absorbed constituents into consideration, 23 constituents were selected as potential Q-marker. A simultaneous quantification method (together with 11 semi-quantitative analysis) was developed and applied to the analysis of 20 batches of commercial Periplocae Cortex on the market. The PLS-DA model was successfully developed to distinguish GP and JP samples. In addition, the artificially mixed GP sample, which contained no less than 10% of the adulterant (JP), could also be correctly identified.

CONCLUSION

Our results indicated that 9 ingredients could be considered as Q-marker of Periplocae Cortex. This study has also demonstrated that the plant metabolomics and network pharmacology could be used as an effective approach for discovering Q-marker of TCM to fulfill the evaluation of overall chemical consistency among samples from different producing areas, harvest seasons, and even those commercial crude drugs, which might be mixed with a small amount of non-medicinal parts.

Anti-nociceptive, anti-inflammatory and anti-arthritic activities of pregnane glycosides from the root bark of Periploca sepium Bunge

ETHNOPHARMACOLOGICAL RELEVANCE

Periploca sepium Bunge (P. sepium) is used in traditional Chinese medicine (TCM) for the treatment of autoimmune diseases, particularly rheumatoid arthritis. Periploca sepium periplosides (PePs), isolated from the root bark of P. sepium, characterized as the cardiac glycosides-free pregnane glycosides fraction, is expected to possess therapeutic potential on inflammatory arthritis.

AIM OF THE STUDY

The current study is designed to evaluate the anti-nociceptive, anti-inflammatory and anti-arthritic activities effects of the PePs.

MATERIALS AND METHODS

The anti-nociceptive activity of PePs was examined in the writhing test and hot-plate test in mice. The anti-inflammatory activity of PePs was determined by the 2, 4-dinitro-1-fluorobenzene (DNFB)-induced ear edema model and the carrageenan induced paw edema model in mice. The anti-arthritic activity of PePs was investigated by evaluating the joint inflammation and arthritis pathology in rat adjuvant induced arthritis (AIA) and murine collagen induced arthritis (CIA). Phytohaemagglutinin M (PHA-M) -elicited human peripheral blood mononuclear cells (PBMCs) were further applied to assess the suppressive activity of PePs on IFN-γ and IL-17 production.

RESULTS

PePs treatment markedly decreased the acetic acid-induced visceral nociceptive response and increased the hot-plate pain threshold. Further, oral administration of PePs exhibited anti-inflammatory activity by decreasing DNFB-induced ear edema in mice and carrageenan-induced paw edema in rats. Moreover, oral treatment of PePs ameliorated joint swelling and attenuated bone erosion in rodent arthritis, and the therapeutic benefits were partially attributed to the suppression of proinflammatory cytokines such IFN-γ and IL-17. Moreover, PePs suppressed the proliferation as well as IFN-γ and IL-17 secretion in PHA-M-elicited human PBMCs in a concentration dependent manner.

CONCLUSIONS

Taken together, our results justified the traditional use of Periploca sepium Bunge for the treatment of diseases associated with inflammation and pain.

Periplocin mediates TRAIL-induced apoptosis and cell cycle arrest in human myxofibrosarcoma cells via the ERK/p38/JNK pathway

BACKGROUND

Periploca sepium is traditionally used in Chinese medicine to treat particularly rheumatic disorders and as a tonic. Periplocin was found as the most cytotoxic compound of its root bark and induced death receptor mediated apoptosis in liposarcoma cells. Sarcomas are a rare type of cancer with only a few treatment options. The five-year survival rate of advanced tumors is low.

PURPOSE

In this study, we investigated the effects of periplocin in two myxofibrosarcoma (MFS)cell lines, MUG-Myx2a and MUG-Myx2b, which are subclones of the same tumor and reflect the tumor´s heterogeneity, and in T60 primary myxofibrosarcoma cells.

METHODS

The xCELLigence system and the CellTiter 96® AQueous assay were used for studying cell viability. FACS and Western blot experiments were used to investigate the effects of periplocin on apoptosis induction, cell cycle distribution, and the expression of cleaved PARP, caspase 3, p53, phospho-histone γH2AX, ERK/phospho ERK, p38/phospho p38, and, finally, JNK/phospho JNK. Additionally, the expression of the apoptotic markers Bim, NOXA, Bak, Bcl-2, Bcl-xl, and the death receptors IGFR, FADD, TRADD, TNFR1A, TRAIL-R1, and TRAIL-R2 were evaluated using reversed real-time PCR.

RESULTS

Periplocin decreased dose-dependently the viability of all MFS cell lines and was more effective than the standard chemotherapeutic doxorubicin. It arrested the cells in the G2/M phase and led to caspase activation. Moreover, periplocin increased the mRNA expression of NOXA, Bak, Bcl-2, and death receptors such as TRAIL-R1 and TRAIL-R2 and the protein expression of ERK/phospho ERK, p38/phospho p38, and JNK/phospho JNK. In all cases, differences in the effects in the different subclones were observed.

CONCLUSION

Periplocin showed promising effects in MFS cells. The higher effectiveness compared to doxorubicin is an important aspect for further research with regard as a treatment option. The different effects of periplocin in the two subclones showed the great importance of intratumoral heterogeneity in MFS therapy.

Characterization of chemical components of Periplocae Cortex and their metabolites in rats using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

Periplocae Cortex, named Xiang-Jia-Pi in China, has been widely used to treat autoimmune diseases, especially rheumatoid arthritis. However, the in vivo substances of Periplocae Cortex remain unknown yet. In this study, an ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used for profiling the chemical components and related metabolites of Periplocae Cortex. A total of 98 constituents were identified or tentatively characterized in Periplocae Cortex: 42 C21 steroidal glycosides, 10 cardiac glycosides, 23 organic acids, 4 aldehydes, 7 triterpenes, and 12 other types. Among them, 18 components were unambiguously identified by comparison with reference standards. In addition, 176 related xenobiotics (34 prototypes and 142 metabolites) were screened out and characterized in rats' biosamples (plasma, urine, bile, and feces) after the oral administration of Periplocae Cortex. Moreover, the metabolic fate of periplocoside S-4a, a C21 steroidal glycoside, was proposed for the first time. In summary, phase II reactions (methylation, glucuronidation, and sulfation), phase I reactions (hydrolysis reactions, oxygenation, and reduction), and their combinations were the predominant metabolic reactions of Periplocae Cortex in rat. It is the first report to reveal the in vivo substances and metabolism feature of Periplocae Cortex. This study also provided meaningful information for further pharmacodynamics study of Periplocae Cortex, as well as its quality control research.

An LC-MS/MS Method for Simultaneous Determination of the Toxic and Active Components of Cortex Periplocae in Rat Plasma and Application to a Pharmacokinetic Study

A sensitive and simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to simultaneously determine the toxic and other active components including isovanillin, scopoletin, periplocin, periplogenin, and periplocymarin after oral administration of cortex periplocae extract to rats. Plasma samples were prepared by protein precipitation with methanol. All compounds were separated on a C₁₈ column with gradient elution using acetonitrile and formic acid aqueous solution (0.1%, v/v) as the mobile phase at a flow rate of 0.3 mL/min. The detection of all compounds was accomplished by multiple-reaction monitoring (MRM) in the positive electrospray ionization mode. The LC-MS/MS method exhibited good linearity for five analytes. The lower limit of quantification (LLOQ) was 0.48 ng/mL for scopoletin, periplogenin, and periplocymarin; 2.4 ng/mL for isovanillin and periplocin. The extraction recoveries of all compounds were more than 90% and the RSDs were below 10%. It was found that the absorption of scopoletin and periplocin was rapid in vivo after oral administration of cortex periplocae extract. Furthermore, periplocymarin possessed abundant plasma exposure. The results demonstrated that the validated method was efficiently applied for the pharmacokinetic studies of isovanillin, scopoletin, periplocin, periplogenin, and periplocymarin after oral administration of cortex periplocae extract.

Rethinking and new perspectives on cardiotoxicity of traditional Chinese medicine

Traditional Chinese Medicine (TCM) has been commonly used in clinical practice for thousands of years and has made enormous contributions to public health in China. However, the adverse effects on the cardiac system or TCM-induced cardiovascular diseases have emerged frequently in recent years, resulting in growing attention to the safety of TCM. Generally, TCM with adverse cardiac effects has typical therapeutic or toxic effects, which are based on specific material basis for efficacy/toxicity, specific clinical symptoms and toxic mechanisms. However, improper strategies adopted for research on the cardiotoxicity of TCM simply follow the basic principles of conventional toxicology and cause exaggerative or incorrect interpretations in the toxicity of TCM. In this review, we aim to present the classification and possible toxic mechanisms for TCM with cardiotoxicity based on the material basis for toxicity to rethink the existing problems in toxicity studies for TCM and provide new perspectives for research on the potential cardiotoxicity of TCM. We hope that this study can offer important theoretical support and scientific advice for the toxicity study and clinical rational use of TCM having cardiotoxicity.

Application of metabolomics in toxicity evaluation of traditional Chinese medicines

Traditional Chinese medicines (TCM) have a long history of use because of its potential complementary therapy and fewer adverse effects. However, the toxicity and safety issues of TCM have drawn considerable attention in the past two decades. Metabolomics is an “omics” approach that aims to comprehensively analyze all metabolites in biological samples. In agreement with the holistic concept of TCM, metabolomics has shown great potential in efficacy and toxicity evaluation of TCM. Recently, a large amount of metabolomic researches have been devoted to exploring the mechanism of toxicity induced by TCM, such as hepatotoxicity, nephrotoxicity, and cardiotoxicity. In this paper, the application of metabolomics in toxicity evaluation of bioactive compounds, TCM extracts and TCM prescriptions are reviewed, and the potential problems and further perspectives for application of metabolomics in toxicological studies are also discussed.

Periplocin, the most anti-proliferative constituent of Periploca sepium, specifically kills liposarcoma cells by death receptor mediated apoptosis

BACKGROUND

During a screening of Chinese plants traditionally used for the treatment of cancer and related diseases, extracts of the root bark of Periploca sepium Bunge showed strong cytotoxic activity.

PURPOSE

Isolate and identify cytotoxic compounds from P. sepium and investigate the effects and mechanism of action on different cancer cell lines.

METHODS

Extracts obtained with solvents of different polarities of the root bark of P. sepium were tested for their anti-proliferative effects. The most active extract was subjected to activity-guided fractionation using different chromatographic methods. The most active compound was further investigated on sarcoma cell lines regarding its effects concerning apoptosis, DNA damage and death receptor expression.

RESULTS

We isolated the cardiac glycosides periplocin, glucosyl divostroside, periplogenin, periplocymarin and periplocoside M with periplocin exhibiting the lowest IC₅₀ value against leukemia and liposarcoma cells. Liposarcomas are rare tumors within the heterogeneous group of soft tissue sarcomas and respond poorly to conventional treatments. Periplocin led to growth inhibition and apoptosis induction by changing the expression of death receptors and inducing DNA double strand breaks in SW-872 cells.

CONCLUSION

Periplocin displays a promising mechanism of action in sarcoma cells because altering the death receptor expression is an interesting target in sarcoma treatment especially to overcome TRAIL resistance.