Esculetin, a natural coumarin compound, evokes Ca2+ movement and activation of Ca2+-associated mitochondrial apoptotic pathways that involved cell cycle arrest in ZR-75-1 human breast cancer cells

Therapeutic potential of esculetin in various cancer types (Review)

Esculetin (Esc), a coumarin derivative and herbal medicinal compound used in traditional Chinese medicine, is extracted from Fraxinus chinensis. Esc has shown notable potential in the inhibition of proliferation, metastasis and cell cycle arrest in various cancer cell lines. The present review is based on research articles regarding Esc in the field of carcinoma, published between 2009 and 2023. These studies have unanimously demonstrated that Esc can effectively inhibit cancer cell proliferation through diverse mechanisms and modulate multiple signaling pathways, such as Wnt/β-catenin, PI3K/Akt, MAPK and janus kinase/signal transducer and activator of transcription-3. In addition, the safety profile of Esc has been demonstrated in credible animal experiments, which has indicated Esc as an effective compound. Furthermore, the combination therapy of Esc with commonly used chemotherapeutic drugs holds great promise. The aim of the present review was to encourage further studies and applications of Esc in cancer therapy.

Pharmacological activities of esculin and esculetin: A review

Esculin and esculetin are 2 widely studied coumarin components of Cortex Fraxini, which is a well-known herbal medicine with a 2000-year history. In vivo and in vitro studies have demonstrated that both have a variety of pharmacological activities, including antioxidant, anti-tumor, anti-inflammatory, antibacterial, antidiabetic, immunomodulatory, anti-atherosclerotic, and so on. Their underlying mechanisms of action and biological activities include scavenging free radicals, modulating the nuclear factor erythroid 2-related factor 2 pathway, regulating the cell cycle, inhibiting tumor cell proliferation and migration, promoting mitochondrial pathway apoptosis, inhibiting the NF-κB and MAPK signaling pathways, regulating CD4+ T cells differentiation and associated cytokine release, inhibiting vascular smooth muscle cells, etc. This review aims to provide comprehensive information on pharmacological studies of esculin and esculetin, which is of noteworthy importance in exploring the therapeutic potential of both coumarin compounds.

Synergy, Additivity and Antagonism between Esculetin and Six Commonly Used Chemotherapeutics in Various Malignant Melanoma Cell Lines-An Isobolographic Analysis

(1) Malignant melanomas are dangerous skin cancers, and the treatment of melanomas with various cytostatic drugs often causes side effects and after their prolonged use resistance to these drugs appears. The aim of this study was to evaluate the anticancer effects of esculetin (a simple coumarin) and to assess pharmacodynamic interactions between esculetin and six commonly used cytostatic drugs (cisplatin, epirubicin, docetaxel, paclitaxel, mitoxantrone and vemurafenib) using an isobolographic analysis. (2) The experiments were carried out on four human malignant melanoma cell lines (FM55P, A375, FM55M2 and SK-MEL28). The effects of esculetin on viability, cell proliferation and cytotoxicity were verified in the range of concentrations of 2-200 μM. (3) Esculetin inhibited, in a dose-dependent manner, malignant melanoma cell viability and proliferation. The IC₅₀ for esculetin ranged from 18.20 ± 2.93 to 120.64 ± 30.39 μM depending on the melanoma cell lines used. The combinations of esculetin with epirubicin and vemurafenib showed antagonistic interactions, the combinations of esculetin with cisplatin, docetaxel and paclitaxel showed additive interactions. For the combinations of esculetin with mitoxantrone, the isobolographic analysis displayed synergy. (4) In the treatment of malignant melanoma, esculetin should not be combined with epirubicin or vemurafenib, due to the reduction of their anticancer effects, while the synergistic interactions (esculetin + mitoxantrone) deserve a preclinical recommendation as a beneficial combination during anticancer therapy.

Antitumor Effects of Esculetin, a Natural Coumarin Derivative, against Canine Mammary Gland Tumor Cells by Inducing Cell Cycle Arrest and Apoptosis

Mammary gland tumors are the most common neoplasms in female dogs, of which 50% are malignant. Esculetin, a coumarin derivative, reportedly induces death in different types of cancer cells. In this study, we explore the anticancer effects of esculetin against CMT-U27 and CF41.mg canine mammary gland tumor cells. Esculetin significantly inhibited the viability and migration of both CMT-U27 and CF41.mg cells in a dose- and time-dependent manner. Flow cytometric analysis and terminal deoxynucleotidyl transferase dUTP nick-end labeling assay revealed increased numbers of annexin-V-positive cells and DNA fragmentation. Furthermore, a cell cycle analysis demonstrated that esculetin blocked the cell progression at the G0/G1 phase and the S phase in CMT-U27 and CF41.mg cells. These results were supported by a Western blot analysis, which revealed upregulated protein expression of cleaved caspase-3, a marker of apoptosis, and downregulated cyclin-dependent kinase 4 and cyclin D1 protein, the cell cycle regulators. In conclusion, this novel study proves that esculetin exerts in vitro antitumor effects by inducing apoptosis and cell cycle arrest in canine mammary gland tumors.

Esculetin has therapeutic potential via the proapoptotic signaling pathway in A253 human submandibular salivary gland tumor cells

Esculetin is a natural lactone that is commonly derived from coumarins. According to previous experiments using human cancer cells, esculetin has potent antitumor activity; it also inhibits proliferation and induces the apoptosis of cancer cells. In the present study, the anti-proliferative effect of esculetin on the submandibular salivary gland tumor cell line, A253, was evaluated via in vitro and in vivo analyses. Furthermore, the anti-cancer effects of esculetin in A253 cells and a xenograft model of salivary gland tumors were determined using 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide and TUNEL assay, apoptosis protein array, quantitative polymerase chain reaction and western blot analysis. Esculetin (50-150 µM) was demonstrated to have an anti-proliferative effect in the A253 cell line in vitro; this observed effect was dependent on the dose and duration of treatment. Esculetin also increased the levels of Bax, cleaved caspase-3, cleaved-9 and cleaved poly (ADP-ribose) polymerase apoptosis-related proteins, and decreased the expression levels of the Bcl-2 anti-apoptotic protein. With respect to apoptosis regulation, esculetin significantly decreased the proliferation of tumor cells in a xenograft model (100 mg/kg/day) for 18 days. Overall, esculetin could be a potential oral anticancer drug against salivary gland cancer.

Esculetin: A review of its pharmacology and pharmacokinetics

Esculetin is a natural dihydroxy coumarin; it is mainly extracted from twig skin and the trunk bark of the Chinese herbal medicine Fraxinus rhynchophylla Hance. Emerging evidence suggests that esculetin has a wide range of pharmacological activities. Based on its fundamental properties, including antioxidant, antiinflammatory, antiapoptotic, anticancer, antidiabetic, neuroprotective, and cardiovascular protective activities, as well as antibacterial activity, among others, esculetin is expected to be a therapeutic drug for specific disease indications, such as cancer, diabetes, atherosclerosis, Alzheimer's disease (AD), Parkinson's disease (PD), nonalcoholic fatty liver disease (NAFLD), and other diseases. The oral bioavailability of esculetin was shown by studies to be low. The extensive glucuronidation was described to be the main metabolic pathway of esculetin and C-7 phenolic hydroxyl to be its major metabolic site. With the development of scientific research technology, the pharmacological effects of esculetin are identified and its potential for the treatment of diseases is demonstrated. The underlining mechanisms of action and biological activities as well as the pharmacokinetic data of the analyzed compound reported so far are highlighted in this review with the aim of becoming a proven, and applicable insight and reference for further studies on the utilization of esculetin.

Antitumor Effect of the Ethanolic Extract from Seeds of Euphorbia lathyris in Colorectal Cancer

The seeds of Euphorbia lathyris have been used in traditional medicine to treat various medical conditions. However, neither all of their active biocompounds nor the molecular mechanisms underlying their therapeutic effects have been described. A new ethanolic extract of defatted flour from mature seeds of Euphorbia lathyris showed a high total polyphenol content and significant antioxidant activity. Chromatographic analysis showed that esculetin, euphorbetin, gaultherin, and kaempferol-3-rutinoside were the most abundant polyphenolic bioactive compounds. Antiproliferative assays showed a high and selective antitumor activity against colon cancer cell lines (T84 and HCT-15). In addition, a significant antiproliferative activity against glioblastoma multiforme cells was also demonstrated. Its mechanism of action to induce cell death was mediated by the overexpression of caspases 9, 3, and 8, and by activation of autophagy. Interestingly, a reduction in the migration capacity of colon cancer cells and a significant antiangiogenic effect on human umbilical vein endothelial cells were also demonstrated. Finally, the extract significantly reduced the subpopulations of cancer stem cells. This extract could be the basis to develop new therapeutic strategies for the treatment of colon cancer, although further experiments will be necessary to determine its in vivo effects.

Artemisia scoparia and Metabolic Health: Untapped Potential of an Ancient Remedy for Modern Use

Botanicals have a long history of medicinal use for a multitude of ailments, and many modern pharmaceuticals were originally isolated from plants or derived from phytochemicals. Among these, artemisinin, first isolated from Artemisia annua, is the foundation for standard anti-malarial therapies. Plants of the genus Artemisia are among the most common herbal remedies across Asia and Central Europe. The species Artemisia scoparia (SCOPA) is widely used in traditional folk medicine for various liver diseases and inflammatory conditions, as well as for infections, fever, pain, cancer, and diabetes. Modern in vivo and in vitro studies have now investigated SCOPA's effects on these pathologies and its ability to mitigate hepatotoxicity, oxidative stress, obesity, diabetes, and other disease states. This review focuses on the effects of SCOPA that are particularly relevant to metabolic health. Indeed, in recent years, an ethanolic extract of SCOPA has been shown to enhance differentiation of cultured adipocytes and to share some properties of thiazolidinediones (TZDs), a class of insulin-sensitizing agonists of the adipogenic transcription factor PPARγ. In a mouse model of diet-induced obesity, SCOPA diet supplementation lowered fasting insulin and glucose levels, while inducing metabolically favorable changes in adipose tissue and liver. These observations are consistent with many lines of evidence from various tissues and cell types known to contribute to metabolic homeostasis, including immune cells, hepatocytes, and pancreatic beta-cells. Compounds belonging to several classes of phytochemicals have been implicated in these effects, and we provide an overview of these bioactives. The ongoing global epidemics of obesity and metabolic disease clearly require novel therapeutic approaches. While the mechanisms involved in SCOPA's effects on metabolic, anti-inflammatory, and oxidative stress pathways are not fully characterized, current data support further investigation of this plant and its bioactives as potential therapeutic agents in obesity-related metabolic dysfunction and many other conditions.

Esculetin Inhibits Proliferation, Invasion, and Migration of Laryngeal Cancer In Vitro and In Vivo by Inhibiting Janus Kinas (JAK)-Signal Transducer and Activator of Transcription-3 (STAT3) Activation

BACKGROUND Laryngeal cancer is one of the most common malignant tumors of the head and neck. Natural compounds in traditional Chinese medicine provide many valuable potential compounds for tumor chemotherapy. Esculetin, a coumarin derivative from several herbs, inhibits proliferation of many types of cancer cells, but its anticancer effect in laryngeal cancer is still not clear. MATERIAL AND METHODS We performed in vitro proliferation assay, invasion assay, and migration assay to assess the effect of esculetin against LC, and in vivo nude mouse xenograft animal model was used as well. Flow cytometry was conducted to analyze the effect of esculetin on cell cycle of LC cells, and Western blot analysis was used to assess the effect esculetin on the JAK-STAT signaling pathway. RESULTS Esculetin remarkably inhibits proliferation, migration, and invasion of LC cells, and reduces in vivo xenograft tumor growth and tumor weight in a dose-dependent manner. Our molecular mechanism study demonstrated that esculetin significantly inhibits STAT3 phosphorylation and blocks translocation of STAT3 into the nucleus, and esculetin also blocks the cell cycle in G1/S phase. CONCLUSIONS In a summary, by inhibiting the STAT3 activation, esculetin shows potential anticancer effects against the laryngeal cancer.

Medicinal properties of Angelica archangelica root extract: Cytotoxicity in breast cancer cells and its protective effects against in vivo tumor development

OBJECTIVE

Although Angelica archangelica is a medicinal and aromatic plant with a long history of use for both medicinal and food purposes, there are no studies regarding the antineoplastic activity of its root. This study aimed to evaluate the cytotoxicity and antitumor effects of the crude extract of A. archangelica root (CEAA) on breast cancer.

METHODS

The cytotoxicity of CEAA against breast adenocarcinoma cells (4T1 and MCF-7) was evaluated by a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Morphological and biochemical changes were detected by Hoechst 33342/propidium iodide (PI) and annexin V/PI staining. Cytosolic calcium mobilization was evaluated in cells staining with FURA-4NW. Immunoblotting was used to determine the effect of CEAA on anti- and pro-apoptotic proteins (Bcl-2 and Bax, respectively). The 4T1 cell-challenged mice were used for in vivo assay.

RESULTS

Using ultra-high-performance liquid chromatography-mass spectrometry analysis, angelicin, a constituent of the roots and leaves of A. archangelica, was found to be the major constituent of the CEAA evaluated in this study (73 µg/mL). The CEAA was cytotoxic for both breast cancer cell lines studied but not for human fibroblasts. Treatment of 4T1 cells with the CEAA increased Bax protein levels accompanied by decreased Bcl-2 expression, in the presence of cleaved caspase-3 and cytosolic calcium mobilization, suggesting mitochondrial involvement in breast cancer cell death induced by the CEAA in this cell line. No changes on the Bcl-2/Bax ratio were observed in CEAA-treated MCF7 cells. Gavage administration of the CEAA (500 mg/kg) to 4T1 cell-challenged mice significantly decreased tumor growth when compared with untreated animals.

CONCLUSION

Altogether, our data show the antitumor potential of the CEAA against breast cancer cells in vitro and in vivo. Further research is necessary to better elucidate the pharmacological application of the CEAA in breast cancer therapy.

Esculetin Inhibits the Survival of Human Prostate Cancer Cells by Inducing Apoptosis and Arresting the Cell Cycle

Background

Prostate cancer (PCa) is one of the most important causes of death in men and thus new therapeutic approaches are needed. In this study, antiproliferative and anti-migration properties of a coumarin derivative esculetin were evaluated.

Methods

Human PCa cell lines PC3, DU145, and LNCaP were treated with various concentrations of esculetin for 24 to 72 hours, and cell viability was determined by the MTT test. Cell cycle and apoptosis were analyzed by using cell-based cytometer. Gene expression levels were assessed by reverse transcription and quantitative real-time PCR, cell migration was determined by the wound healing assay. The protein expression was measured by Western blotting.

Results

Esculetin inhibited cell proliferation in a dose- and time-dependent manner. Cell migration was inhibited by esculetin treatment. Administration of esculetin significantly reduced the cells survival, induced apoptosis and caused the G1 phase cell cycle arrest shown by image-based cytometer. The induced expression of cytochrome c, p53, p21 and p27, and down-regulated CDK2 and CDK4 may be the underlying molecular mechanisms of esculetin effect. Esculetin suppressed phosphorylation of Akt and enhanced protein expression of tumor-suppressor phosphatase and tensin homologue.

Conclusions

Our findings showed that the coumarin derivative esculetin could be used in the management of PCa. However, further in vivo research is needed.

Bioinformatics analysis of RNA sequencing data reveals multiple key genes in uterine corpus endometrial carcinoma

In the present study, the RNA sequencing (RNA-seq) data of uterine corpus endometrial carcinoma (UCEC) samples were collected and analyzed using bioinformatics tools to identify potential genes associated with the development of UCEC. UCEC RNA-seq data were downloaded from The Cancer Genome Atlas database. Differential analysis was performed using edgeR software. A false discovery rate <0.01 and |log₂(fold change)|>1 were set as the cut-off criteria to screen for differentially expressed genes (DEGs). Differential gene co-expression analysis was performed using R/EBcoexpress package in R. DEGs in the gene co-expression network were subjected to Gene Ontology analysis using the Database for Annotation, Visualization and Integration Discovery. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis was also performed on the DEGs using KOBAS 2.0 software. The ConnectivityMap database was used to identify novel drug candidates. A total of 3,742 DEGs were identified among the 552 UCEC samples and 35 normal controls, and comprised 2,580 upregulated and 1,162 downregulated genes. A gene co-expression network consisting of 129 DEGs and 368 edges was constructed. Genes were associated with the cell cycle and the tumor protein p53 signaling pathway. Three modules were identified, in which genes were associated with the mitotic cell cycle, nuclear division and the M phase of the mitotic cell cycle. Multiple key hub genes were identified, including cell division cycle 20, cyclin B2, non-SMC condensin I complex subunit H, BUB1 mitotic checkpoint serine/threonine kinase, cell division cycle associated 8, maternal embryonic leucine zipper kinase, MYB proto-oncogene like 2, TPX2, microtubule nucleation factor and non-SMC condensin I complex subunit G. In addition, the small molecule drug esculetin was implicated in the suppression of UCEC progression. Overall, the present study identified multiple key genes in UCEC and clinically relevant small molecule agents, thereby improving our understanding of UCEC and expanding perspectives on targeted therapy for this type of cancer.

Esculetin exerts antitumor effect on human gastric cancer cells through IGF-1/PI3K/Akt signaling pathway

In this study, we aimed to investigate the antitumor effect of esculetin, a coumarin derivative extracted from natural plants, on human gastric cancer cells, and to illustrate the potential mechanisms. The results showed that esculetin exhibited anti-proliferative effects against gastric cancer cells and induced their apoptosis in a dose dependent manner with lower toxicity against normal gastric epithelial cells. Mechanism study indicated that esculetin induced gastric cancer MGC-803 cells apoptosis by triggering the activation of mitochondrial apoptotic pathway through reducing the mitochondrial membrane potential (MMP), increasing Bax/Bcl-2 ratio, activating caspase-3 and caspase-9 activity, and increasing cytochrome c release from mitochondria. Further study showed that the pro-apoptotic effects of esculetin were associated with down-regulation of insulin-like growth factor-1/ phosphatidylinositide 3-kinase/protein kinase B (IGF-1/PI3K/Akt) signaling pathway. Activation of IGF-1/PI3K/Akt pathway by IGF-1 abrogated the pro-apoptotic effects of esculetin, while inhibition of IGF-1/PI3K/Akt pathway by triciribine or LY294002 enhanced the pro-apoptotic effects of esculetin. In addition, esculetin inhibited in vivo tumor growth with no obvious toxicity following subcutaneous inoculation of MGC-803 cells in nude mice, and inhibited activation of IGF-1/PI3K/Akt pathway in tumor tissue.

CONCLUSION

These results indicate that esculetin could inhibit cell proliferation and induce apoptosis of gastric cancer cells through IGF-1/PI3K/Akt mediated mitochondrial apoptosis pathway, and may be a novel effective chemotherapeutic agent against gastric cancer.

Esculetin induces apoptosis of SMMC-7721 cells through IGF-1/PI3K/Akt-mediated mitochondrial pathways

Esculetin (6,7-dihydroxycoumarin) is a coumarin derivative extracted from natural plants and has been reported to have anticancer activity. However, the mechanism by which esculetin prevents human hepatic cancer cell growth is still largely unknown. In this study, we investigated the effect of esculetin on human hepatocellular carcinoma (HCC) SMMC-7721 cells and explored the cell signal mechanism. Our data indicated that esculetin induced apoptosis in SMMC-7721 cells, which were supported by DAPI staining and Annexin V/PI staining. Meanwhile, esculetin increased the activities of caspase-3 and caspase-9, promoted bax expression, decreased bcl-2 expression, and triggered collapse of mitochondrial membrane potential, and increased cytochrome c release from mitochondria. In addition, the inactivation of IGF-1, PI3K, and Akt was observed after esculetin administration. Furthermore, pretreatment with IGF-1 before esculetin administration abrogated the pro-apoptotic effects of esculetin, while PI3K inhibitor increased the pro-apoptotic effects of esculetin. These results indicated that esculetin induced the apoptosis of SMMC-7721 cells through IGF-1/PI3K/Akt-regulated mitochondrial dysfunction.

Chemopreventive Activity of MGN-3/Biobran Against Chemical Induction of Glandular Stomach Carcinogenesis in Rats and Its Apoptotic Effect in Gastric Cancer Cells

In the current study, we investigated the chemopreventive activity of arabinoxylan rice bran, MGN-3/Biobran, against chemical induction of glandular stomach carcinogenesis in rats. Gastric cancer was induced by carcinogen methylnitronitrosoguanidine (MNNG), and rats received MNNG alone or MNNG plus Biobran (40 mg/kg body weight) for a total of 8 months. Averaged results from 2 separate readings showed that exposure to MNNG plus Biobran caused gastric dysplasia and cancer (adenocarcinoma) in 4.5/12 rats (9/24 readings, 37.5%), with 3.5/12 rats (7/24 readings, 29.2%) showing dysplasia and 1/12 rats (8.3%) developing adenocarcinoma. In contrast, in rats treated with MNNG alone, 8/10 (80%) developed dysplasia and adenocarcinoma, with 6/10 rats (60%) showing dysplasia and 2/10 rats (20%) developing adenocarcinoma. The effect of combining both agents was also associated with significant suppression of the expression of the tumor marker Ki-67 and remarkable induction in the apoptotic gastric cancer cells via mitochondrial-dependent pathway as indicated by the upregulation in p53 expression, Bax expression, downregulation in Bcl-2 expression, an increase in Bax/Bcl-2 ratio, and an activation of caspase-3. In addition, Biobran treatment induced cell-cycle arrest in the subG1 phase, where the hypodiploid cell population was markedly increased. Moreover, Biobran treatment protected rats against MNNG-induced significant decrease in lymphocyte levels. We conclude that Biobran provides protection against chemical induction of glandular stomach carcinogenesis in rats and may be useful for the treatment of human patients with gastric cancer.