Solamargine inhibits the migration and invasion of HepG2 cells by blocking epithelial-to-mesenchymal transition

Main chemical constituents and mechanism of anti-tumor action of Solanum nigrum L

OBJECTIVE

Solanum nigrum L. (SNL) is a natural drugwith diverse bioactive components and multi-targeted anti-tumor effects, gaining increasing attention in clinical application.

METHOD AND RESULTS

This paper reviews the studies on SNL by searching academic databases (Google Scholar, PubMed, Science Direct,and Web of Science, among others), analyzing its chemical compositions (alkaloids, saponins, polysaccharides, and polyphenols, among others), andbriefly describes the anti-tumor mechanisms of the main components.

DISCUSSION

This paper discusses the shortcomings of the current research on SNL and proposes corresponding solutions, providing theoretical support for further research on its biological functions and clinical efficacy.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

Active components of Solanum nigrum and their antitumor effects: a literature review

Cancer poses a serious threat to human health and overall well-being. Conventional cancer treatments predominantly encompass surgical procedures and radiotherapy. Nevertheless, the substantial side effects and the emergence of drug resistance in patients significantly diminish their quality of life and overall prognosis. There is an acute need for innovative, efficient therapeutic agents to address these challenges. Plant-based herbal medicines and their derived compounds offer promising potential for cancer research and treatment due to their numerous advantages. Solanum nigrum (S. nigrum), a traditional Chinese medicine, finds extensive use in clinical settings. The steroidal compounds within S. nigrum, particularly steroidal alkaloids, exhibit robust antitumor properties either independently or when combined with other drugs. Many researchers have delved into unraveling the antitumor mechanisms of the active components present in S. nigrum, yielding notable progress. This literature review provides a comprehensive analysis of the research advancements concerning the active constituents of S. nigrum. Furthermore, it outlines the action mechanisms of select monomeric anticancer ingredients. Overall, the insights derived from this review offer a new perspective on the development of clinical anticancer drugs.

The Therapeutic Value of Solanum Steroidal (Glyco)Alkaloids: A 10-Year Comprehensive Review

Steroidal (glycol)alkaloids S(G)As are secondary metabolites made of a nitrogen-containing steroidal skeleton linked to a (poly)saccharide, naturally occurring in the members of the Solanaceae and Liliaceae plant families. The genus Solanum is familiar to all of us as a food source (tomato, potato, eggplant), but a few populations have also made it part of their ethnobotany for their medicinal properties. The recent development of the isolation, purification and analysis techniques have shed light on the structural diversity among the SGAs family, thus attracting scientists to investigate their various pharmacological properties. This review aims to overview the recent literature (2012-2022) on the pharmacological benefits displayed by the SGAs family. Over 17 different potential therapeutic applications (antibiotic, antiviral, anti-inflammatory, etc.) were reported over the past ten years, and this unique review analyzes each pharmacological effect independently without discrimination of either the SGA's chemical identity or their sources. A strong emphasis is placed on the discovery of their biological targets and the subsequent cellular mechanisms, discussing in vitro to in vivo biological data. The therapeutic value and the challenges of the solanum steroidal glycoalkaloid family is debated to provide new insights for future research towards clinical development.

In Vitro Cytotoxic Effect of Aqueous Extracts from Leaves and Rhizomes of the Seagrass Posidonia oceanica (L.) Delile on HepG2 Liver Cancer Cells: Focus on Autophagy and Apoptosis

Aqueous extracts from Posidonia oceanica's green and brown (beached) leaves and rhizomes were prepared, submitted to phenolic compound and proteomic analysis, and examined for their potential cytotoxic effect on HepG2 liver cancer cells in culture. The chosen endpoints related to survival and death were cell viability and locomotory behavior, cell-cycle analysis, apoptosis and autophagy, mitochondrial membrane polarization, and cell redox state. Here, we show that 24 h exposure to both green-leaf- and rhizome-derived extracts decreased tumor cell number in a dose-response manner, with a mean half maximal inhibitory concentration (IC₅₀) estimated at 83 and 11.5 μg of dry extract/mL, respectively. Exposure to the IC₅₀ of the extracts appeared to inhibit cell motility and long-term cell replicating capacity, with a more pronounced effect exerted by the rhizome-derived preparation. The underlying death-promoting mechanisms identified involved the down-regulation of autophagy, the onset of apoptosis, the decrease in the generation of reactive oxygen species, and the dissipation of mitochondrial transmembrane potential, although, at the molecular level, the two extracts appeared to elicit partially differentiating effects, conceivably due to their diverse composition. In conclusion, P. oceanica extracts merit further investigation to develop novel promising prevention and/or treatment agents, as well as beneficial supplements for the formulation of functional foods and food-packaging material with antioxidant and anticancer properties.

Anticancer activity of glycoalkaloids from Solanum plants: A review

Cancer is still one of the main causes of death worldwide. For this reason, new compounds that have chemotherapeutic potential have been identified. One such group of substances is Solanaceae glycoalkaloids (GAs). They are natural compounds produced by plants widely used in traditional medicine for healing many disorders. Among others, GAs exhibit significant antitumor properties, for example, a strong inhibitory effect on cancer cell growth. This activity can result in the induction of tumor cell apoptosis, which can occur via different molecular pathways. The molecular mechanisms of the action of GAs are the subject of intensive research, as improved understanding could lead to the development of new cancer therapies. The genetic basis for the formation of neoplasms are mutations in protooncogenes, suppressors, and apoptosis-controlling and repair genes; therefore, substances with antineoplastic properties may affect the levels of their expression or the levels of their expression products. Therapeutic compounds can be applied separately or in combination with other drugs to increase the efficiency of cancer therapy; they can act on the cell through various mechanisms at different stages of carcinogenesis, inducing the process of apoptosis, blocking cell proliferation and migration, and inhibiting angiogenesis. This review summarizes the newest studies on the anticancer properties of solanine (SN), chaconine (CH), solasonine (SS), solamargine (SM), tomatine (TT) and their extracts from Solanum plants.

Solamargine Alleviates Proliferation and Metastasis of Cervical Cancer Cells by Blocking the CXCL3-Mediated Erk Signaling Pathway

Solamargine has unique antitumor efficacy in a variety of cancers. The study is to explore the role of solamargine in cervical cancer. HeLa and SiHa cells were exposed to solamargine treatment at divergent concentrations (0, 5, 10, and 20 μM). The antitumor role of solamargine in cervical cancer cells was determined by cell counting kit 8 (CCK-8), colony formation, scratch test, transwell assay, and western blot. The expression of mRNAs regulating the extracellular regulated protein kinases (Erk) pathway in solamargine-treated cells was detected by qRT-PCR. Rescue experiments were conducted to explore the effect of C-X-C motif chemokine ligand 3 (CXCL3). Following that, we inhibited Erk1/2 by PD98059 to investigate the interplay between CXCL3 and Erk pathway in solamargine-treated cells by measuring migration, invasion, and related matrix metalloproteinase (MMP) expressions. Solamargine inhibited the viability, proliferation, migration, and invasion of cervical cancer cells in a dose-dependent manner. The expression of p-Erk1/2 was downregulated by solamargine. CXCL3 overexpression abrogated the antitumor effect of solamargine on cervical cancer cells. The inhibition of the Erk signaling pathway restored the inhibiting role of solamargine which interfered with CXCL3 overexpression, in invasion, migration, and expressions of MMP-2 and MMP-9 in cervical cancer cells. Moreover, solamargine inhibited the growth of tumor in vivo xenograft model. Solamargine alleviated proliferation and metastasis of cervical cancer cells by blocking the CXCL3-mediated Erk signaling pathway.

Isosteroidal alkaloids from Fritillaria hupehensis Hsiao et K.C.Hsia: Synthesis and biological evaluation of alkaloid derivatives as potential cytotoxic agents

One new cevanine isosteroidal alkaloid named 5,6-anhydrohupehenine (1), together with five known alkaloids (2-6) were isolated from Fritillaria hupehensis Hsiao et K.C.Hsia, among which 5,6-anhydrohupehenine (1) exhibited strong inhibitory activity against HepG2 (IC₅₀ = 12.21 μM) and MCF-7 (IC₅₀ = 22.05 μM) cancer cells. Therefore, a total of 33 5,6-anhydrohupehenine derivatives (9a-9s, 10a-10f, 11a-11b, and 12a-12f) were synthesized and evaluated for their cytotoxic activity. The cytotoxicity evaluation of all 5,6-anhydrohupehenine derivatives against HepG2 and MCF-7 human cancer cells revealed that 9s displayed best activity against HepG2 cells with IC₅₀ at 1.27 μM. Further biological evaluations on 9s showed that it inhibited the proliferation of HepG2 cells and induced apoptosis of the HepG2 cells by activating cleaved caspase-3. Moreover, 9s exhibited strong antimetastatic potential. These results suggest that 5,6-anhydrohupehenine is a promising compound to be designed as novel cytotoxic agents.

Paris saponin H inhibits the proliferation of glioma cells through the A1 and A3 adenosine receptor‑mediated pathway

Paris saponin H (PSH) is a type of steroid saponin derived from Rhizoma Paridis (RP; the rhizome of Paris). In our previous studies, saponins from RP exerted antiglioma activity in vitro. However, the effects of PSH on glioma have not been elucidated. The aim of the present study was to evaluate the effects of PSH on U251 glioblastoma cells and elucidate the possible underlying mechanism. The cells were treated with PSH at various concentrations for 48 h, and the cell viability, invasion, apoptosis and cycle progression were assessed using specific assay kits. The activation of Akt, 44/42‑mitogen‑activated protein kinase (MAPK) and the expression levels of A1 adenosine receptor (ARA1) and ARA3 were assessed by western blotting. The results demonstrated that PSH inhibited cell viability, migration and invasion, and induced apoptosis. Treatment of U251 cells with PSH induced the upregulation of p21 and p27, and the downregulation cyclin D1 and S‑phase kinase associated protein 2 protein expression levels, which induced cell cycle arrest at the G1 phase. The results also demonstrated that PSH inhibited the expression of ARA1, and the agonist of ARA1, 2‑chloro‑N6‑cyclopentyladenosine, reversed the effects of PSH. Hypoxia induced increases in the ARA3, hypoxia‑inducible factor‑1α (HIF‑1α) and vascular endothelial growth factor (VEGF) protein expression levels, which were associated with the activation of the Akt and P44/42 MAPK pathways. Compared with the hypoxia group, PSH inhibited the expression levels of ARA3, HIF‑1α and VEGF, as well as the phosphorylation levels of Akt and 44/42 MAPK, and repressed HIF‑1α transcriptional activity. Furthermore, the results demonstrated that PSH inhibited the expression of HIF‑1α by inhibiting the phosphorylation of Akt and 44/42 MAPK mediated by ARA3. Taken together, these results suggested that PSH reduced U251 cell viability via the inhibition of ARA1 and ARA3 expression, and further inhibited Akt and 44/42 MAPK phosphorylation, induced apoptosis and cell cycle arrest.

Discovery of VEGFR-2 inhibitors exerting significant anticancer activity against CD44+ and CD133+ cancer stem cells (CSCs): Reversal of TGF-β induced epithelial-mesenchymal transition (EMT) in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a malignancy characterized by neoangiogenesis, which is an augmented production of proangiogenic factors by the tumor and its adjacent infected cells. These dysregulated angiogenic factors are the therapeutic targets in anti-angiogenic drug development. The signaling pathway of vascular endothelial growth factor (VEGF)/VEGFR-2 is crucial for controlling the angiogenic responses in endothelial cells (ECs). In this study, we carried out a rational drug design approach wherein we have identified the novel orally bioavailable compound VS 8 as a potent VEGFR-2 inhibitor, which remarkably suppresses hVEGF and hVEGFR-2 expression in HUVECs and exhibits significant anti-angiogenic effects in CAM assay. Besides, VS 8 significantly induces apoptosis in HCC cell line (Hep G2). Later we examined its effectiveness against CD44+ and CD133+ CSCs. Here, VS 8 was found to be active against CSCs, and adequate for the cessation of the cell cycle at 'G₀/G₁' and 'S' phase in CD44+ and CD133+ CSCs respectively. Factually, transforming growth factor-β (TGF-β) stimulated epithelial-mesenchymal transition (EMT) induces invasion and migration of HCC cells, which results in the metastasis. Therefore, we studied the effect of VS 8 on EMT markers using flow cytometry, which suggested that VS 8 significantly upregulates E-cadherin (epithelial biomarker) and downregulates vimentin (mesenchymal biomarker). Further, VS 8 downregulates the expression of EMT-inducing transcription factors (EMT-TFs), i.e., SNAIL. Altogether, our findings indicate that VS 8 could be a promising drug candidate for cancer therapy.

Cordycepin suppresses the migration and invasion of human liver cancer cells by downregulating the expression of CXCR4

Liver cancer is a worldwide threat to human health. High expression levels of C-X-C chemokine receptor type 4 (CXCR4) have been reported to promote the migration and invasion capacities of liver cancer cells. Cordycepin, extracted from Cordyceps militaris, has anti-inflammatory, antioxidant and anticancerous properties. Therefore, in the present study, migration assays, western blotting, reverse transcription-quantitative PCR and immunofluorescence analyses were conducted to determine whether cordycepin was able to suppress the migration and invasion abilities of liver cancer cells by inhibiting CXCR4 expression. The results suggested that cordycepin notably inhibited migration and invasion, and decreased the expression of CXCR4 in a dose-dependent manner. Activation of phosphorylated (p-) NF-κB inhibitor α (IκBα) and p-P65, the principal components of the NF-κB signaling pathway, was also downregulated. In addition, cordycepin markedly suppressed the nuclear translocation of P65, but had no effect on the expression of total IκBα (t-IκBα) and total P65 (t-P65). JSH-23, an inhibitor of the NF-κB pathway, impaired the migration of liver cancer cells, and was found to act synergistically with cordycepin. Furthermore, cordycepin treatment reduced the chemotactic migration ability of liver cancer cells to stromal cell-derived factor 1 (SDF1), which was significantly enhanced following treatment with JSH-23. Collectively, the present results indicated that cordycepin inhibited the nuclear translocation of P65 by preventing p-IκBα activation; this resulted in the downregulation of CXCR4 expression, and subsequently, in the impaired migration and invasion abilities of liver cancer cells and attenuated reactivity to SDF1. The current study revealed a novel mechanism for the antimetastatic activity of cordycepin and its potential to exert positive synergistic effects with other compounds for the treatment of liver cancer.

Alkaloids from Traditional Chinese Medicine against hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has become one of the major diseases that are threatening human health in the 21st century. Currently there are many approaches to treat liver cancer, but each has its own advantages and disadvantages. Among various methods of treating liver cancer, natural medicine treatment has achieved promising results because of their superiorities of high efficiency and availability, as well as low side effects. Alkaloids, as a class of natural ingredients derived from traditional Chinese medicines, have previously been shown to exert prominent anti-hepatocarcinogenic effects, through various mechanisms including inhibition of proliferation, metastasis and angiogenesis, changing cell morphology, promoting apoptosis and autophagy, triggering cell cycle arrest, regulating various cancer-related genes as well as pathways and so on. As a consequence, alkaloids suppress the development and progression of liver cancer. In this study, the mechanisms of representative alkaloids against hepatocarcinoma in each class are described systematically according to the structure classification, which mainly divides alkaloids into piperidine alkaloids, isoquinoline alkaloids, indole alkaloids, terpenoids alkaloids, steroidal alkaloids and other alkaloids. Besides using them alone, synergistic effects created together with other chemotherapy drugs and some special preparation methods also have been demonstrated. In this review, we have summarized the potential roles of several common alkaloids in the prevention and treatment of HCC, by revising the preclinical studies, highlighting the potential applications of alkaloids when they function as a therapeutic choice for HCC treatment, and integrating them into clinical practices.

Solamargine inhibits gastric cancer progression by regulating the expression of lncNEAT1_2 via the MAPK signaling pathway

Solamargine, a derivative from the steroidal solasodine in Solanum species, has exhibited anticancer activities in numerous types of cancer; however, its role in gastric cancer (GC) remains unknown. In the present study, it was demonstrated that Solamargine suppressed the viability of five gastric cancer cell lines in a dose‑dependent manner and induced notable alterations in morphology. Treatment with Solamargine promoted cell apoptosis (P<0.01). Solamargine increased the expression of long noncoding RNA (lnc) p53 induced transcript and lnc nuclear paraspeckle assembly transcript 1 (NEAT1)_2 (P<0.01) in GC by reducing the phosphorylation of extracellular signal‑regulated kinase (Erk)1/2 mitogen‑activated protein kinase (MAPK). To gain insight into the potential mechanism, an Erk1/2 inhibitor (U0126) was applied. The results revealed that lncNEAT1_2 expression levels increased, which was consistent with the effects of Solamargine. Downregulation of lncNEAT1_2 in GC cells revealed no effect on the expression levels of total Erk1/2 and, and counteracted the effect of Solamargine. Solamargine was observed to increase the expression of lncNEAT1_2 via the Erk1/2 MAPK signaling pathway. Of note, the knockdown of lncNEAT1_2 reduced the inhibitory effect of Solamargine (P<0.05). Additionally, experiments in vivo and in primary GC cells from patients demonstrated that Solamargine significantly suppressed tumor growth (P<0.05). In vivo analysis of a xenograft mouse model further supported that Solamargine could induce the apoptosis of cancer cells in tumor tissue as observed by a terminal deoxynucleotidyl transferase‑mediated dUTP‑biotin nick end labeling and H&E staining (P<0.05). Experiments in primary GC cells from patients verified the anti‑tumor effect of Solamargine. In summary, the findings of the present study indicated that Solamargine inhibited the progression of GC by regulating lncNeat1_2 via the MAPK pathway.

Alpha-mangostin, an active compound in Garcinia mangostana, abrogates anoikis-resistance in human hepatocellular carcinoma cells

Anoikis-resistance is a critical step in cancer progression, especially during the process of metastasis. During this phase, the cancer phenotype that causes cell survival in detachment conditions, drug resistance, and epithelial-to-mesenchymal transition (EMT) is altered. Inhibition of anoikis-resistance can potentially be the molecular target in cancer therapy. Alpha-mangostin, an active compound in Garcinia mangostana, has been reported for its cell-death induction and its chemosensitizing and anti-metastatic properties in many cancer cell types, such as ovarian cancer, lung cancer, and hepatocellular carcinoma. We, therefore, have investigated whether alpha-mangostin could sensitize anoikis in human hepatocellular carcinoma (HepG2). The established anoikis-resistant HepG2 displayed more aggressive malignant behaviors, including rapid proliferation, doxorubicin resistance, up-regulated anti-apoptotic protein levels, and EMT phenotype. Alpha-mangostin significantly sensitized anoikis in HepG2 through the inhibition of cell survival by induced caspase-9, caspase-8 and caspase-3 activities, increased pro-apoptotic protein (Bax, Bim, t-Bid) levels, and decreased anti-apoptotic protein (c-FLIP, Mcl-1) levels. Besides, alpha-mangostin significantly reduced cell re-adhesion and migration, matrix metalloproteinases-2 (MMP-2) and MMP-9 secretions, and EMT-involved protein (N-cadherin, αV, β1 integrin, and vimentin) expressions. AKT and ERK signaling pathways were dramatically suppressed, which indicated that alpha-mangostin inhibited anoikis-resistance via the inhibition of these pathways in HepG2. These findings support the development of alpha-mangostin to be used in the treatment of anoikis-resistant liver cancer.

Benzo(a)pyrene promotes Hep-G2 cell migration and invasion by upregulating phosphorylated extracellular signal-regulated kinase expression

Benzo(a)pyrene (BaP), a carcinogenic component of cigarette smoke, has been reported to activate extracellular signal-regulated kinase (ERK) in cancer cells. Furthermore, activated ERK is associated with liver cancer cell invasion and metastasis. Therefore, the aim of the present study was to investigate the potential role of phosphorylated (p)-ERK in BaP-induced Hep-G2 cell migration and invasion. An MTT assay was used to determine the effects of BaP treatment on Hep-G2 cell proliferation. Wound-healing and Transwell invasion assays were employed to assess the migration and invasion abilities of Hep-G2 cells. Western blot analysis was applied to detect the expression of proteins. The results of the present study demonstrated that BaP treatment was able to increase the level of p-ERK protein expression in Hep-G2 cells. BaP treatment promoted Hep-G2 cell migration and invasion. The ERK inhibitor, U0126, was able to block the migration and invasion abilities of Hep-G2 cells induced by BaP. The results of the present study demonstrated that BaP treatment promoted the migration and invasion of Hep-G2 cells by upregulating p-ERK expression.

Solamargine, a bioactive steroidal alkaloid isolated from Solanum aculeastrum induces non-selective cytotoxicity and P-glycoprotein inhibition

Background

Solanum aculeastrum fruits are used by some cancer sufferers as a form of alternative treatment. Scientific literature is scarce concerning its anticancer activity, and thus the aim of the study was to assess the in vitro anticancer and P-glycoprotein inhibitory potential of extracts of S. aculeastrum fruits. Furthermore, assessment of the combinational effect with doxorubicin was also done.

Methods

The crude extract was prepared by ultrasonic maceration. Liquid-liquid extraction yielded one aqueous and two organic fractions. Bioactive constituents were isolated from the aqueous fraction by means of column chromatography, solid phase extraction and preparative thin-layer chromatography. Confirmation of bioactive constituent identity was done by nuclear magnetic resonance and ultra-performance liquid chromatography mass spectrometry. The crude extract and fractions were assessed for cytotoxicity and P-glycoprotein inhibition in both cancerous and non-cancerous cell lines using the sulforhodamine B and rhodamine-123 assays, respectively.

Results

Both the crude extract and aqueous fraction was cytotoxic to all cell lines, with the SH-SY5Y neuroblastoma cell line being most susceptible to exposure (IC₅₀ = 10.72 μg/mL [crude], 17.21 μg/mL [aqueous]). Dose-dependent P-glycoprotein inhibition was observed for the crude extract (5.9 to 18.9-fold at 100 μg/mL) and aqueous fraction (2.9 to 21.2 at 100 μg/mL). The steroidal alkaloids solamargine and solanine were identified. While solanine was not bioactive, solamargine displayed an IC₅₀ of 15.62 μg/mL, and 9.1-fold P-glycoprotein inhibition at 100 μg/mL against the SH-SY5Y cell line. Additive effects were noted for combinations of doxorubicin against the SH-SY5Y cell line.

Conclusions

The crude extract and aqueous fraction displayed potent non-selective cytotoxicity and noteworthy P-glycoprotein inhibition. These effects were attributed to solamargine. P-glycoprotein inhibitory activity was only present at concentrations higher than those inducing cytotoxicity, and thus does not appear to be the likely mechanism for the enhancement of doxorubicin’s cytotoxicity. Preliminary results suggest that non-selective cytotoxicity may hinder drug development, however, further assessment of the mode of cell death is necessary to determine the route forward.