Extracts of Celastrus orbiculatus exhibit anti-proliferative and anti-invasive effects on human gastric adenocarcinoma cells

Effect of Celastrus Orbiculatus Extract on proliferation and apoptosis of human Burkitt lymphoma cells

The lymphoma incidence rate is on the rise, with invasive forms particularly prone to relapse following conventional treatment, posing a significant threat to human life and wellbeing. Numerous studies have shown that traditional Chinese botanical drug medicine offers promising therapeutic benefits for various malignancies, with previous experimental findings indicating that Celastrus orbiculatus extract effectively combats digestive tract tumors. However, its impact on lymphoma remains unexplored. This study aims to investigate the impact and underlying mechanisms of COE on the proliferation and apoptosis of Burkitt lymphoma cells. We diluted COE in RPMI-1640 medium to create various working concentrations and introduced it to human Burkitt lymphoma Raji and Ramos cells. To evaluate cell viability, we used the CCK-8 assay, and we observed morphological changes using HE staining. We also conducted Annexin V-PI and JC-1 staining experiments to assess apoptosis. By combining the cell cycle experiment with the EDU assay, we gained insights into the effects of COE on DNA replication in lymphoma cells. Using Western blotting, we detected alterations in apoptosis-related proteins. In vivo experiments revealed that following COE intervention, tumor volume decreased, survival time was prolonged, spleen size reduced, and the expression of tumor apoptosis-related proteins changed. Our findings indicate that COE effectively inhibits lymphoma cell proliferation and promotes apoptosis by regulating these apoptosis-related proteins.

Betulonic Acid, as One of the Active Components of the Celastrus orbiculatus Extract, Inhibits the Invasion and Metastasis of Gastric Cancer Cells by Mediating Cytoskeleton Rearrangement In Vitro

Gastric cancer is a type of malignant tumor that seriously threatens human life and health. Invasion and metastasis present difficulties in the treatment of gastric cancer, and the remodeling of the tumor cytoskeleton plays an important role in mediating the ability of tumor cells to achieve invasion and metastasis. Previous experimental results suggest that Celastrus orbiculatus extract can regulate cytoskeletal remodeling in gastric cancer, but the active component has not been determined. Betulonic acid, as an effective component of COE, inhibits the invasion and metastasis of gastric cancer cells by regulating cytoskeletal remodeling in vitro; its specific mechanisms have been studied here. After betulonic acid was dissolved, it was diluted to various working concentrations in RPMI-1640 medium and added to AGS, HGC-27 and GES-1 cell lines. Cell viability was assessed by CCK-8 and colony formation assays. Cytoskeleton staining was used to detect changes in cytoskeleton morphology. Functional assays including wound healing assays and transwell assays were used to detect the invasion and migration of cells. The effect of betulonic acid on cell invasion and migration was clearly and precisely observed by high-content imaging technology. Western blotting was used to detect the regulation of matrix metalloproteinase-related proteins and epithelial–mesenchymal transformation-related proteins. We found that betulonic acid inhibited the migration and invasion of gastric cancer cells. Therefore, betulonic acid inhibits the invasion and metastasis of gastric cancer cells by mediating cytoskeletal remodeling and regulating epithelial mesenchymal transformation.

Natural products targeting the PI3K-Akt-mTOR signaling pathway in cancer: A novel therapeutic strategy

The phosphatidylinositol 3-kinase (PI3K)-Akt and the mammalian target of rapamycin (mTOR) represent two vital intracellular signaling pathways, which are associated with various aspects of cellular functions. These functions play vital roles in quiescence, survival, and growth in normal physiological circumstances as well as in various pathological disorders, including cancer. These two pathways are so intimately connected to each other that in some instances these are considered as one unique pathway crucial for cell cycle regulation. The purpose of this review is to emphasize the role of PI3K-Akt-mTOR signaling pathway in different cancer conditions and the importance of natural products targeting the PI3K-Akt-mTOR signaling pathway. This review also aims to draw the attention of scientists and researchers to the assorted beneficial effects of the numerous classes of natural products for the development of new and safe drugs for possible cancer therapy. We also summarize and critically analyze various preclinical and clinical studies on bioactive compounds and constituents, which are derived from natural products, to target the PI3K-Akt-mTOR signaling pathway for cancer prevention and intervention.

28-Hydroxy-3-oxoolean-12-en-29-oic Acid, a Triterpene Acid from Celastrus Orbiculatus Extract, Inhibits the Migration and Invasion of Human Gastric Cancer Cells In Vitro

Gastric cancer is the fifth most common tumor and has the third-highest mortality rate among various malignant tumors, and the survival rate of patients is low. Celastrus orbiculatus extract has been shown to inhibit the activity of a variety of tumors. This study explored the inhibitory effect of the oleanane-type triterpenoid acid 28-hydroxy-3-oxoolean-12-en-29-oic acid molecule from Celastrus orbiculatus extract on gastric cancer cell invasion and metastasis and determined its mechanism. 28-Hydroxy-3-oxoolean-12-en-29-oic acid was first diluted to various concentrations and then used to treat SGC-7901 and BGC-823 cells. Cell proliferation was assessed by an MTT (thiazole blue) assay. Transwell and wound healing assays were used to assess cell invasion and migration. High-content imaging technology was used to further observe the effects of the drug on cell invasion and migration. Western blotting was used to assess the effects on the expression of matrix metalloproteinases (MMPs) and the effects on epithelial-mesenchymal transition (EMT)-related proteins and phosphorylation-related proteins. We found that 28-Hydroxy-3-oxoolean-12-en-29-oic acid inhibited the migration and invasion of SGC-7901 and BGC-823 gastric cancer cells in a dose-dependent manner. Consequently, 28-hydroxy-3-oxoolean-12-en-29-oic acid decreased the expression of EMT-related proteins and MMPs in gastric cancer cells and reduced protein phosphorylation, inhibiting the migration and invasion of gastric cancer cells.

Celastrus orbiculatus Extracts Inhibit Human Hepatocellular Carcinoma Growth by Targeting mTOR Signaling Pathways

OBJECTIVE

To characterize the molecular mechanism underlying the antineoplastic activity of Celastrus orbiculatus Thunb. extracts (COE).

METHODS

The human hepatocellular carcinoma HepG2 cells with mammalian target of rapamycin (mTOR) knockdown expressed (HepG2/mTOR) were constructed using molecular biological technology. In vitro, the HepG2/mTOR^- cells were treated with COE at various concentrations (10, 20, 40, 80, 160 and 320 µ g/mL). Cell viability was determined using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assays. According to the half-maximal inhibitory concentration (IC₅₀) value (140 mg/L), the concentrations of COE in the subsequent experiment was set to alleviate cytotoxicity. The HepG2/mTOR^- cells were divided into 5 groups: negative control (untreated), COE treatment groups (40, 80, 120 mg/L COE) and positive control group (cisplatin, DDP, 2 mg/L), respectively. Wild-type HepG2 cells were used as a blank control. The effects of COE on the cell apoptosis were analyzed by flow cytometry and transmission electronic microscopy (TEM), respectively. The protein expression levels of mTOR signal pathways were determined by Western blotting. In vivo, HepG2/mTOR^- cells (2 × 10⁶ cell/mice) were subcutaneously injected into the right flank of nude mice. Thirty-six female nude mice were randomly assigned to 6 groups according to body weight (6 mice per group) as follows: solvent vehicle control, Banmao Capsule treated group (BM, 195 mg/kg), Tegafur, Gimeracil and Oteracil Potassium Capsules (10 mg/kg) treated group, and different dosages of COE (10, 20, 40 mg/kg) groups. Tumor growth was monitored and immunohistochemical staining was used to examine the expression of apoptosis-related proteins in tumor tissues.

RESULTS

COE inhibited the proliferation significantly in a concentration-dependent manner in HepG2/mTOR^- cells (P<0.01). COE significantly induced the apoptosis of HepG2/mTOR^- cells (P<0.01), and the apoptotic bodies can be observed under TEM. COE significantly inhibits the proteins expression of mTOR-related signal pathways. In vivo, COE significantly inhibited tumor growth in nude mice (P<0.01). Moreover, the results showed that COE down-regulated the expression of Bcl-2 and Bcl-xL, and up-regulated the levels of Bax and caspase-3 protein (P<0.01).

CONCLUSION

COE was a potential chemotherapeutic drug in HCC treatments via targeting mTOR signal pathway.

Extracts of Celastrus Orbiculatus Inhibit Cancer Metastasis by Down-regulating Epithelial-Mesenchymal Transition in Hypoxia-Induced Human Hepatocellular Carcinoma Cells

OBJECTIVE

To evaluate the effects of Celastrus Orbiculatus extracts (COE) on metastasis in hypoxia-induced hepatocellular carcinoma cells (HepG2) and to explore the underlying molecular mechanisms.

METHODS

The effect of COE (160, 200 and 240 µ g/mL) on cell viability, scratch-wound, invasion and migration were studied by 3-4,5-dimethyl-2-thiazolyl-2,5-diphenyl-2-H-tetrazolium bromide (MTT), scratch-wound and transwell assays, respectively. CoCl₂ was used to establish a hypoxia model in vitro. Effects of COE on the expressions of E-cadherin, vimentin and N-cadherin were investigated with Western blot and immunofluorescence analysis, respectively.

RESULTS

COE inhibited proliferation and metastasis of hypoxia-induced hepatocellular carcinoma cells in a dose-dependent manner (P<0.01). Furthermore, the expression of epithelial-mesenchymal transition (EMT) related markers were also remarkably suppressed in a dose-dependent manner (P<0.01). In addition, the upstream signaling pathways, including the hypoxia-inducible factor 1 α (Hif-1 α) and Twist1 were suppressed by COE. Additionally, the Hif-1 α inhibitor 3-5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1), potently suppressed cell invasion and migration as well as expression of EMT in hypoxia-induced HepG2 cells. Similarly, the combined treatment with COE and YC-1 showed a synergistic effect (P<0.01) compared with the treatment with COE or YC-1 alone in hypoxia-induced HepG2 cells.

CONCLUSIONS

COE significantly inhibited the tumor metastasis and EMT by suppressing Hif-1 α/Twist1 signaling pathway in hypoxia-induced HepG2 cell. Thus, COE might have potential effect to inhibit the progression of HepG2 in the context of tumor hypoxia.

Natural products: a hope for glioblastoma patients

Glioblastoma (GBM) is one of the most aggressive malignant tumors with an overall dismal survival averaging one year despite multimodality therapeutic interventions including surgery, radiotherapy and concomitant and adjuvant chemotherapy. Few drugs are FDA approved for GBM, and the addition of temozolomide (TMZ) to standard therapy increases the median survival by only 2.5 months. Targeted therapy appeared promising in in vitro monolayer cultures, but disappointed in preclinical and clinical trials, partly due to the poor penetration of drugs through the blood brain barrier (BBB). Cancer stem cells (CSCs) have intrinsic resistance to initial chemoradiation therapy (CRT) and acquire further resistance via deregulation of many signaling pathways. Due to the failure of classical chemotherapies and targeted drugs, research efforts focusing on the use of less toxic agents have increased. Interestingly, multiple natural compounds have shown antitumor and apoptotic effects in TMZ resistant and p53 mutant GBM cell lines and also displayed synergistic effects with TMZ. In this review, we have summarized the current literature on natural products or product analogs used to modulate the BBB permeability, induce cell death, eradicate CSCs and sensitize GBM to CRT.

Celastrus orbiculatus extracts induce cell cycle arrest and apoptosis in human esophageal squamous carcinoma ECA-109 cells in vitro via the PI3K/AKT/mTOR signaling pathway

Recently, Celastrus orbiculatus ethyl acetate extracts (COE) have been investigated for their anticancer effects on digestive tract tumors. However, the therapeutic effects of COE on esophageal squamous carcinoma cells (ESCC) have not been investigated. In the present study, the effects of COE on the cell cycle and apoptosis of ESCCs were assessed in vitro, and it was revealed that COE treatment triggered G₀/G₁ cell cycle arrest, and induced DNA damage and apoptosis in a dose-dependent manner in ESCC. Activation of the phosphatidylinositol 3-kinase/protein kinase-B/mechanistic target of rapamycin (mTOR) pathway was also suppressed by COE. Additionally, the combined treatment with COE and rapamycin (an mTOR inhibitor) acted synergistically in ECA-109 cells compared with the treatment with COE or rapamycin alone. These findings extend the understanding of the action of COE and suggest that COE has potential as a treatment option for ESCC as a single treatment or in combination.

Celastrus orbiculatus extracts induce apoptosis and inhibit invasion by targeting the maspin gene in human gastric adenocarcinoma cells

Celastrus orbiculatus Thunb. has been used as a remedy against cancer and inflammatory diseases for thousands of years in China. Maspin is expressed in normal cells and downregulated in prostate tumor cells. The underlying mechanisms between C. orbiculatus extract (COE) and maspin remain unclear. In the present study, 3 target-specific 19–25 nucleotide maspin small interfering RNAs were designed and synthesized to knockdown maspin expression. The effects of COE on MGC-803/maspin⁻ cell proliferation were evaluated by the MTT assay. Apoptosis was measured by flow cytometry. Invasive activity was measured with the Transwell assay and the associated molecular mechanisms were assessed by western blot analysis. The results demonstrated that COE significantly promoted the expression of maspin (P<0.01) to induce apoptosis and inhibit invasion and migration in MGC803 cells. The expression levels of phosphorylated (p)-p38 mitogen-activated protein kinase (MAPK), phospho-extracellular regulated protein kinase (Erk), B cell lymphoma-2-associated X protein and caspase-3 were increased in the MGC-803/maspin⁻ cells in a dose-dependent manner. The Erk, B-cell lymphoma 2, p-Akt, Akt and p-mechanistic target of rapamycin (mTOR) protein in MGC-803/maspin⁻ cells were reduced in a dose-dependent manner. This indicated that COE may inhibit invasion and migration through phosphoinositide 3-kinase/Akt/mTOR and MAPK signaling pathways in MGC-803/maspin⁻ cells. In conclusion, COE has the ability to improve the expression of maspin to induce apoptosis and inhibit invasion and migration in human gastric adenocarcinoma cells.

Ethanol extract of Ilex hainanensis Merr. exhibits anti-melanoma activity by induction of G1/S cell-cycle arrest and apoptosis

OBJECTIVE

To evaluate anti-melanoma effect of ethanol extract of Ilex hainanensis Merr. (IME) and elucidate its underlying mechanism.

METHODS

Thirty-six tumor-bearing mice were randomized into 6 groups (n=6) as follows: model group, IME 25, 50, 100, and 200 mg/kg groups and dacarbazine (DTIC) 70 mg/kg group. The mice in the IME treatment groups were intragastrically administered with IME 25, 50, 100 or 200 mg/kg per day, respectively. The mice in the DTIC group were intraperitoneally injected with DTIC 70 mg/kg every 2 days. The drug administration was lasting for 14 days. The cell viability was evaluated by 3-(4,5-dime-thylthylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay. Flow cytometry was employed to detect cell cycle and apoptosis. The gene and protein expressions of nuclear factor κB-p65 (NF-κB-p65), Bcl-2, B-cell lymphomaextra large (Bcl-xL) and Bax were detected by quantitative real-time polymerase chain reaction and Western blot analyses. Caspases-3, -8, and -9 activities were detected using the colorimetric method. In addition, a B16-F10 melanoma xenograft mouse model was used to evaluate the anti-cancer activity of IME in vivo. Furthermore, a survival experiment of tumor-bearing mice was also performed to evaluate the possible toxicity of IME.

RESULTS

IME significantly inhibited the proliferation of B16-F10 cells (P<0.01). Flow cytometric analysis showed that IME induced G₁/S cell cycle arrest and apoptosis (both P<0.01). IME inhibited activation of NF-κB, decreased the gene and protein expressions of Bcl-2, Bcl-xL, and increased the gene and protein expressions of Bax (all P<0.01). In addition, IME induced the activation of Caspases-3, -8, and -9 in B16-F10 cells. The study in vivo showed that IME significantly reduced tumor volume (P<0.01), and the inhibitory rate came up to 68.62%. IME also induced large areas of necrosis and intra-tumoral apoptosis that correlated with a reduction in tumor volume. Survival experiment showed that treatment with IME for 14 days significantly prolonged survival time and 20% of mice in the IME 200 mg/kg group were still alive until the 50th day. Notably, IME showed no apparent side-effects during the treatment period.

CONCLUSION

IME exhibited significant anti-melanoma activity in vitro and in vivo, suggesting that IME might be a promising effective candidate with lower toxic for malignant melanoma therapy.

Celastrus orbiculatus extract triggers apoptosis and autophagy via PI3K/Akt/mTOR inhibition in human colorectal cancer cells

Celastrus orbiculatus is used as a folk medicine in China for the treatment of numerous diseases. The ethyl acetate extract of Celastrus orbiculatus (COE) also displays a wide range of anti-cancer activities in the laboratory. However, the effectiveness of COE-induced autophagy and its mechanism of action in colorectal cancer cells have not been investigated thus far. The present study analyzed the effect of COE on HT-29 cell viability, apoptosis and autophagy using MTT assay, flow cytometry, transmission electron microscopy and western blotting. Additionally, the autophagy inhibitor 3-methyladenine and the autophagy inducer rapamycin were used to further explore the effects of COE-induced autophagy in HT-29 cells. The present study also examined whether the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR)/p70 ribosomal protein S6 kinase (p70S6K) signaling pathway was involved in the regulation of COE-induced autophagy. The results revealed that COE inhibited HT-29 cell proliferation and decreased cell survival in a time- and dose-dependent manner, and that COE possessed the ability to induce both apoptosis and autophagy in HT-29 cells. Furthermore, autophagy and apoptosis induced by COE synergized to inhibit colorectal cancer growth. In addition, COE treatment decreased the phosphorylation of Akt and its downstream effectors mTOR and p70S6K. Taken together, these results demonstrate that both autophagy and apoptosis were activated during COE treatment of HT-29 cells, and that COE-induced autophagy decreases the viability of HT-29 cells via a mechanism that may depend on the PI3K/Akt/mTOR/p70S6K signaling pathway. Furthermore, compounds that induce autophagy administered in combination with COE may be an attractive strategy for enhancing the anti-tumor potency of COE in colorectal cancer.

Celastrus orbiculatus extract inhibits the migration and invasion of human glioblastoma cells in vitro

BACKGROUND

Gliomas are highly aggressive tumors of the nervous system, and current treatments fail to improve patient survival. To identify substances that can be used as treatments for gliomas, we examined the effect of Celastrus orbiculatus extract (COE) on the invasion and migration of human glioblastoma U87 and U251 cells in vitro.

METHODS

The effects of COE on cell viability and adhesion were tested using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay and cell adhesion assay, respectively. The effects of COE on cell migration and invasion were assessed by a wound-healing assay and transwell migration and invasion assays. The effects of COE on the expression of epithelial-mesenchymal transition (EMT)-related proteins and matrix metalloproteinases (MMPs) were evaluated using western blot and gelatin zymography, respectively. Finally, the effect of COE on actin assembly was observed using phalloidin-tetramethylrhodamine isothiocyanate labeling and confocal laser scanning microscopy.

RESULTS

We found that COE inhibited the adhesion, migration, and invasion of U87 and U251 cells in a dose-dependent manner. COE reduced N-cadherin and vimentin expression, increased E-cadherin expression, and reduced MMP-2 and MMP-9 expression in U87 and U251 cells. Furthermore, COE inhibited actin assembly in U87 and U251 cells.

CONCLUSIONS

COE attenuates EMT, MMP expression, and actin assembly in human glioblastoma cells, thereby inhibiting their adhesion, migration, and invasion in vitro.