Hederacolchiside A1 Research Articles

Abstract 483: Hederacolchiside A1 inhibits autophagy via CTSC inhibition and inhibits growth in colon cancer

Abstract Background: Autophagy is a normal regulatory process that degrades non-functional or unnecessary cellular components. The degradation of components provides materials for the synthesis of cellular components and, during tumor development, may provide energy. Therefore, autophagy regulation may have potential therapeutic uses in oncology. The triterpenoid saponin hederacolchiside A1 (HA1) has potent antitumor effects; however, its role in autophagy is still unknown. Methods: In the present study, we used human colon cancer cells (SW480 and HT29) and mouse colon cancer cells (CT26) for the main experiments, and several additional cancer cell lines for other experiments. To assess the autophagy dysregulation caused by HA1, we evaluated the protein expressions of two autophagy markers (LC3 and SQSTM1) using Western blotting and the changes in organelles using LC3 puncta assay and transmission electron microscopy. We compared the effects of HA1 and other autophagy inhibitors. Additionally, we compared the HA1-induced decrease in cathepsin C (CTSC) expression in tumors and non-tumors using publicly available data. The effect of HA1 on tumor growth was evaluated in vitro using a three-dimensional spheroid model and patient-derived colon organoids, and in vivo based on tumor growth in a subcutaneous injection mouse model. Results: HA1 treatment resulted in marked vacuolization of colon and other cancer cells. Additionally, autophagy was induced by the accumulation of LC3-II and SQSTM1. These findings were supported by increased LC3 puncta and abnormal organelle morphology. Compared to treatment with other autophagy inhibitors, HA1 treatment resulted in the formation of distinct vacuoles and increased LC3 and SQSTM1, similar to chloroquine treatment. The publicly available data showed that the lysosomal protease CTSC was increased in several cancers, including colon cancer, compared to the normal tissues. Furthermore, HA1 decreased the CTSC expression and enzymatic activity independently of the proteasome degradation, resulting in autophagy dysregulation and, subsequently, autophagy flux inhibition. HA1 inhibited cell growth and induced cell cycle arrest in the two-dimensional culture, three-dimensional spheroids, patient-derived colon cancer organoids, and the in vivo experiments. Conclusion: HA1 inhibits cell growth and induces autophagy dysregulation. Therefore, HA1 may be a potential therapeutic agent in colon cancer. Citation Format: Solbi Kim, Eunji Kim, Minju Han, Youn Seo Oh, Sora Kang, Heung Jin Jeon, Hyo Jin Lee. Hederacolchiside A1 inhibits autophagy via CTSC inhibition and inhibits growth in colon cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 483.

Hederacolchiside A1 Suppresses Autophagy by Inhibiting Cathepsin C and Reduces the Growth of Colon Cancer.

While autophagy degrades non-functional or unnecessary cellular components, producing materials for synthesizing cellular components, it can also provide energy for tumor development. Hederacolchiside A1 (HA1) derived from anemone raddeana has anticancer effects on several carcinomas by inducing apoptosis or exhibiting cytotoxicity, but the relationship with autophagy has not been studied. We investigated the association between HA1 and autophagy and evaluated its anticancer effect on colon cancer. HA1 induced accumulation of the autophagy-related markers LC3B and SQSTM1, with distinct vacuolar formation, unlike other autophagy inhibitors; the effects were similar to those of chloroquine. In addition, HA1 decreased the expression and proteolytic activity of lysosomal protein cathepsin C, reduced the growth of colon cancer cells in vitro, and inhibited tumor growth in vivo. It also reduced the expression of Ki-67 and cathepsin C in mouse tissues and reduced the growth of spheroids and organoids composed of cancer cells. Taken together, these results imply that HA1 regulates cell growth and autophagy and has potential as a promising therapeutic agent in colon cancer.

Synthesis, antitumor activity evaluation and mechanistic study of novel hederacolchiside A1 derivatives bearing an aryl triazole moiety

In an attempt to arrive at a more potent antitumor agent than the parent natural saponin hederacolchiside A1, 23 hederacolchiside A1 derivatives (4a-4w) were synthesized via Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition and screened in vitro for cytotoxicity against six human cancer cell lines. The structure-activity relationship of these compounds was elucidated, and the biological screening results showed that most of the compounds exhibited moderate to high levels of antitumor activities against the tested cell lines and some of them displayed more potent inhibitory activities compared with hederacolchiside A1. Compound 4f showed a 2- to 7-fold more potent activity than hederacolchiside A1. The mechanistic study of 4f revealed that this compound can induce cell apoptosis in HepG2 cells via mitochondrial-mediated intrinsic pathways.

Antischistosomal Properties of Hederacolchiside A1 Isolated from Pulsatilla chinensis.

Background: Schistosomiasis is a major neglected disease for which the current control strategy involves mass treatment with praziquantel, the only available drug. Hence, there is an urgent need to develop new antischistosomal compounds. Methods: The antischistosomal activity of hederacolchiside A1 (HSA) were determined by total or female worm burden reductions in mice harboring Schistosoma japonicum or S. mansoni. Pathology parameters were detected on HSA against 1-day-old S. japonicum-harboring mice. Moreover, we confirmed the antischistosomal effect of HSA on newly transformed schistosomula (NTS) of S. japonicum in vitro. Results: HSA, a natural product isolated from Pulsatilla chinensis (Bunge) Regel, was initially corroborated to possess promising antischistosomal properties. We demonstrated that HSA had high activity against S. japonicum and S. mansoni less in 11 days old parasites harbored in mice. The antischistosomal effect was even more than the currently used drugs, praziquantel, and artesunate. Furthermore, HSA could ameliorate the pathology parameters in mice harboring 1-day-old juvenile S. japonicum. We also confirmed that HSA-mediated antischistosomal activity is partly due to the morphological changes in the tegument system when NTS are exposed to HSA. Conclusions: HSA may have great potential to be an antischistosomal agent for further research.

Hederacolchiside A1 suppresses proliferation of tumor cells by inducing apoptosis through modulating PI3K/Akt/mTOR signaling pathway

ObjectiveHederacolchiside A1, exhibits cytostatic and cytotoxic activity against various cancer cells in vitro, however, the mechanism is not well understood. MethodsIn this study, Hederacolchiside A1 from Pulsatilla chinensis was isolated and tested its anticancer activity and mechanism. Hederacolchiside A1 could inhibit proliferation of A549, SMMC-7721, BEL-7402, and MCF-7 cells by MTT assay. Investigations of apoptosis of treated cancer cells were identified in hederacolchiside A1 by flow cytometric analysis of annexin V expression. ResultsBased on the results of western blotting and JC-1 staining, hederacolchiside A1 reduced the mitochondrial membrane potential and Bcl-2 protein levels, whereas cleaved caspase-3 was higher. Furthermore, hederacolchiside A1 effectively inhibited the phosphorylations of phosphatidylinositol 3 kinase (PI3K), protein kinase B (Akt), and mammalian target of rapamycin (mTOR). In vivo study showed that hederacolchiside A1 (3.0, 4.5, and 6.0 mg/kg, ip) could significantly inhibit the weight of tumor in an H22 xenograft model. Similar inhibitory activities were observed when the compound (3.25, 7.5, and 15.0 mg/kg, ig) was tested in nude mice xenograft tumor models using human breast carcinoma MCF-7 cells. ConclusionThese data indicated that hederacolchiside A1 suppressed the proliferation of human tumor cells by inducing apoptosis through modulating the PI3K/Akt/mTOR signaling pathway.

Quantitative and qualitative analyses of cytotoxic triterpenoids in the rhizomes of Anemone raddeana using HPLC and HPLC-ESI-Q/TOF-MS

Anemone raddeana Regel, a Traditional Chinese Medicine, has been demonstrated to possess cytotoxicity and anti-inflammatory activities. The purpose of this study is to establish analytical methods to identify and quantify the major active constituents in Anemone raddeana. A high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-Q/TOF-MS) was used to identify the components in the title plant material. To quantify the major components, a HPLC-UV method was developed and validated. The results showed that 37 compounds were identified based on the MS data and retention times. The contents of eight main bioactive compounds were determined by HPLC simultaneously. These methods could be used to effectively evaluate the quality of A. raddeana and provide a valuable reference for further study. In addition, the cytotoxicity activity of the different fractions of A. raddeana was determined. Hederacolchiside A1 (f) showed promising activity against ten human cancer cell lines with IC50 values from 0.29 to 3.48 μM.

Synthesis and cytotoxicity of oleanolic acid trisaccharide saponins

An array of oleanolic acid-type saponins based on β-hederin has been synthesized in a linear or one-pot manner. The cell viability assays indicate that synthetic saponins show antiproliferation activities in three cancer cell lines with IC50 values of 2.4–15.1 μM and hederacolchiside A1 being the most potent. The results demonstrate that the type of terminal monosaccharides and linkage position have apparent effects on cytotoxicities and selectivities of these saponins against cancer cell lines tested. This study is helpful for future development of more potent anticancer leads.

Pharmacokinetic studies of active triterpenoid saponins and the total secondary saponin from Anemone raddeana Regel.

The rhizome of Anemone raddeana Regel, a Traditional Chinese Medicine (TCM) which has a robust history treating rheumatism and neuralgia. The total secondary saponin (TSS) from it has demonstrated antitumor activity. In this study, a rapid and validated LC-MS/MS method was developed to simultaneously determine the active compounds (Hederacolchiside A1 and Eleutheroside K). Analytes were separated on a reverse-phase C18 column with acetonitrile-water (5mmol/L ammonium acetate) as the mobile phase. This assay showed acceptable linearity (r>0.99) over the concentration range 5-1000 nmol/L for two analytes. The intra- and inter-day precision was within 8.06% and accuracy was ranged from -3.16% to 3.34% for two analytes. The mean extraction recoveries of analytes and IS from rat plasma were all more than 76.0%. Under the developed analytical conditions, the obtained values of main pharmacokinetic parameters (Cmax and AUC0-t) indicated that the pure compounds were more efficient than the TSS extract in Hederacolchiside A1 and Eleutheroside K absorption. In addition, pharmacokinetic studies of two individual compounds demonstrated their poor oral absorption in rat (aF%, 0.019-1.521). In the study of absorption and transportation of Hederacolchiside A1 and Eleutheroside K in Caco-2 cell monolayer model, the uptake permeability was in 10-6cm/sec range suggesting poor absorption, which confirmed the previous pharmacokinetic profiles in vivo. Interestingly, the uptake ratio of them declined significantly when treated with phloridzin (SGLT1 inhibitor). It indicated that the absorption of Hederacolchiside A1 in intestine was mainly through positive transport and SGLT1 might participate in its active absorption.

Nitric oxide-donating derivatives of hederacolchiside A1: Synthesis and biological evaluation in vitro and in vivo as potential anticancer agents

A series of nitric oxide (NO) donating derivatives of hederacolchiside A1 bearing triterpenoid saponin motif were designed, synthesized and evaluated for their anticancer activity. All of the tested furoxan-based NO releasing compounds showed significant proliferation inhibitory activities. Especially compound 6a exhibited strong cytotoxicity (IC50=1.6–6.5μM) against four human tumor cell lines (SMMC-7721, NCI-H460, U251, HCT-116) in vitro and the highest level of NO releasing. Furthermore, compound 6a was revealed low acute toxicity to mice and weak haemolytic activity with potent tumor growth inhibition against mice H22 hepatocellular cells in vivo (51.5%).

Synthesis and biological evaluation of Hederacolchiside A1 derivatives as anticancer agents

Modification of Hederacolchiside A1 (HA1) on 28-COOH gave a series of novel triterpenoid saponin compounds containing ester or amide group. Comparing with natural product HA1, several derivatives showed decreased toxicity in the mice acute toxicity trial and increased the anticancer activity in vitro. Especially compound 1 exhibited the strongest antiproliferative activities against human cancer cell lines tested (IC50=1.1–4.6μM) and potent tumor inhibition rate in vivo (46.8%).

Pores Formation on Cell Membranes by Hederacolchiside A1 Leads to a Rapid Release of Proteins for Cytosolic Subproteome Analysis

Hederacolchiside A1 was used to progressively permeabilize the membrane of human melanoma MEL-5 cells. Holes formation was followed by Scanning Electron Microscopy and interaction of the saponin with cholesterol and phospholipids by TOF-SIMS. 2D-LC-MS/MS and 2D-SDS-PAGE show that the release of soluble proteins into serum-free culture media increases with time. This can lead to a new rapid and efficient strategy to analyze the cytosolic subproteome and it opens the door to get information from the cytosolic compartment for clinical proteomic studies.

Inhibition of HUVEC tubulogenesis by hederacolchiside-A1 is associated with plasma membrane cholesterol sequestration and activation of the Ha-Ras/MEK/ERK cascade

Neoangiogenesis is critical to cancer proliferation and metastasis and constitutes an attractive target for cancer therapy. It has previously been demonstrated that hederacolchiside-A1 (HCol-A1), a triterpenoid saponin from Hedera colchica Koch, has antimelanoma potential. The goal of this study was to evaluate, in vitro, if in addition to its tumoricidal effect on melanoma cells, HCol-A1 might affect endothelial cell network formation. We investigated whether HCol-A1 affects matrigel-induced tubulogenesis and inhibits the viability (WST-1 assay) of human umbilical vein endothelial cells (HUVECs). To provide structure-activity relationships (SAR), studies were conducted on HCol-A1, oleanolic acid and hederacolchiside A (HCol-A), a triterpenoid saponin which possess the same sugar sequence as Hcol-A1. Plasma membrane cholesterol sequestration was studied by labelling with [3H]cholesterol and assayed with HCol-A1-cholesterol complexes. HCol-A1 signalling was investigated using immunoassays. In contrast to HCol-A and oleanolic acid, HCol-A1 inhibited matrigel-induced angiogenesis at micromolar concentration. Plasma membrane cholesterol sequestration was found to be critical for this activity. Activation of the Ras/MEK/ERK cascade appears to be one of the mechanisms by which Hcol-A1 affects HUVEC network formation. The predominant activation of the Ha-Ras isoform, which decreases HUVEC-tolerance to apoptosis, might contribute to the high susceptibility of this cell line to HCol-A1. Since cholesterol sequestration affects cell confluence-dependent remodelling of endothelial membranes and vascular endothelial growth factor receptor-2 activity, these results raise the possibility that Hcol-A1 might slow-down cancer proliferation and metastasis in vivo by inhibiting critical aspects of neoangiogenesis. Further in vivo studies are needed to verify this hypothesis.

In addition to membrane injury, an affinity for melanin might be involved in the high sensitivity of human melanoma cells to hederacolchiside A1.

We previously reported that hederacolchiside A1 (Hcol A1), a new oleanene saponin isolated from Hedera colchica Koch (Araliaceae) exhibits a preferential cytotoxicity on a pigmented melanoma cell line. The present study confirms the high susceptibility of melanoma cell lines to this drug and shows concentrations producing a 50% decrease in cell content (IC50 values) inversely proportional to the melanin content of each cell line. At cytotoxic concentrations, Hcol A1 induces membrane-damaging effects within 6 h, cytoplasmic vacuolization within 24 h, and non-apoptotic cell death within 48 h. Using a new high-resolution magic-angle spinning nuclear magnetic resonance method, we have shown for the first time that this hederasaponin specifically interacts with melanin. The dissociation constant (2.7 mM) is comparable to those observed with drugs known to interact with melanin. Taking into consideration that the IC50 values were inversely proportional to the melanin in each cell line, our data suggest that, in addition to the delayed membrane injury induced by this drug, the ability of Hcol A1 to bind melanin could contribute to the higher toxicity of Hcol A1 in pigmented melanoma cells.

Antileishmanial activity of three saponins isolated from ivy, alpha-hederin, beta-hederin and hederacolchiside A1, as compared to their action on mammalian cells cultured in vitro.

The in vitro antileishmanial activity of three saponins isolated from ivy, alpha-hederin, beta-hederin and hederacolchiside A1, was investigated on Leishmania infantum. The assessment of possible targets (membrane integrity, membrane potential, DNA synthesis and protein content) was performed in both Leishmania promastigotes and human monocytes (THP1 cells). Results observed in Leishmania showed that the saponins exhibited a strong antiproliferative activity on all stages of development of the parasite by altering membrane integrity and potential: hederacolchiside A1 appeared to be the most active compound against both promastigotes and amastigotes. Results observed in THP1 cells demonstrated that the saponins exerted also a potent antiproliferative activity against human monocytes, by producing a significant DNA synthesis inhibition. The ratio between antileishmanial activity on amastigotes and toxicity to human cells suggested that the saponins could be considered as possible antileishmanial drugs.