Cinobufotalin Capsule Combined with Zoledronic Acid in the Treatment of Pain Symptoms and Clinical Efficacy in Prostate Cancer Patients with Bone Metastases: A Retrospective Study.

OBJECTIVE: To retrospectively analyse the effects of cinobufotalin capsule combined with zoledronic acid on pain symptoms and clinical efficacy of prostate cancer patients with bone metastases. METHODS: Patients with prostate cancer with bone metastasis admitted to our hospital from January 2021 to December 2022 were selected as study subjects. They were divided into the control group (treated with zoledronic acid) and the combined group (cinobufotalin capsules were added on the control group basis) according to different recorded treatment methods. The efficacies of the two groups after matching, lumbar L1-4 bone mineral density (BMD), serum calcium, serum phosphorus, visual analogue scale (VAS) score and Karnofsky performance status (KPS) score before and after treatment were compared, and adverse reactions were statistically analysed. RESULTS: A total of 102 patients were included in the study, encompassing 52 patients in the combined group and 50 patients in the control group. After 1:1 preference score matching, 64 patients were included in the two groups. No significant difference in baseline data was found between the two groups (p > 0.05). The total effective rate of the combination group was higher than that of the control group (p < 0.05). No significant differences in L1-4 bone mineral density, serum calcium and phosphorus, VAS score and KPS score were observed between the two groups prior to treatment (p > 0.05). After treatment, the L1-4 bone mineral density (BMD) and KPS score of the combined group decreased to less than those of the control group, the VAS score was lower than that of the control group, and the serum calcium and phosphorus level increased but less than that of the control group (p < 0.05). No significant difference in adverse reactions was found between the two groups (p > 0.05). CONCLUSIONS: Cinobufotalin capsule combined with zoledronic acid had ideal efficacy in the treatment of prostate cancer in patients with bone metastasis. This approach could improve their bone density and quality of life, improve their calcium and phosphorus metabolism, reduce their pain symptoms and provide increased safety. It may have an important guiding role in formulating future clinical treatment plans for patients with prostate cancer and bone metastasis.

Bufotalin enhances apoptosis and TMZ chemosensitivity of glioblastoma cells by promoting mitochondrial dysfunction via AKT signaling pathway.

Glioblastoma multiforme (GBM) is the most prevalent and lethal primary intracranial neoplasm in the adult population, with treatments of limited efficacy. Recently, bufotalin has been shown to have anti-cancer activity in a variety of cancers. This investigation aims to investigate the effect of bufotalin on GBM and elucidate its potential underlying mechanism. Our results show that bufotalin not only inhibits the proliferation and epithelial-mesenchymal transition (EMT) but also triggers apoptosis in GBM cells. The result of RNA-seq indicated that bufotalin could induce mitochondrial dysfunction. Moreover, our observations indicate that bufotalin induces an excessive accumulation of intracellular reactive oxygen species (ROS) in GBM cells, leading to mitochondrial dysfunction and the dephosphorylation of AKT. Moreover, bufotalin improved TMZ sensitivity of GBM cells in vitro and in vivo. In conclusion, bufotalin enhances apoptosis and TMZ chemosensitivity of glioblastoma cells by promoting mitochondrial dysfunction via AKT signaling pathway.

Resibufogenin: An Emerging Therapeutic Compound with Multifaceted Pharmacological Effects - A Comprehensive Review.

Resibufogenin (RBG), a significant bufadienolide compound found in the traditional Chinese medicine Chansu, has garnered increasing attention in recent years for its wide range of pharmacological effects. This compound has shown promising potential in various therapeutic areas, including oncology, cardiology, and respiratory medicine. Among its notable properties, the anticancer effects of RBG are particularly striking, positioning it as a potential candidate for innovative cancer treatments. The mechanism of action of RBG is diverse, impacting various cellular processes. Its anticancer efficacy has been observed in different types of cancer cells, where it induces apoptosis and inhibits cell proliferation. Beyond its oncological applications, RBG also demonstrates substantial anti-inflammatory and antiviral activities. These properties suggest its utility in managing chronic inflammatory disorders and viral infections, respectively. The compound's cardiotonic effects are also noteworthy, providing potential benefits in cardiovascular health, particularly in heart failure management. Additionally, RBG has shown effectiveness in blood pressure regulation and respiratory function improvement, making it a versatile agent in the treatment of hypertension and respiratory disorders. However, despite these promising aspects, systematic reviews focusing specifically on RBG are limited. This article aims to address this gap by comprehensively reviewing RBG's origin, physiological, and pharmacological effects. The review will serve as a crucial reference for clinicians and researchers interested in the therapeutic applications of RBG, highlighting its potential in various medical domains. By synthesizing current research findings, this review will facilitate a deeper understanding of RBG's role in medicine and encourage further investigation into its clinical uses.

Mechanism of bufalin inhibition of colon cancer liver metastasis by regulating M2-type polarization of Kupffer cells induced by highly metastatic colon cancer cells.

Patients with metastatic colorectal cancer often have poor outcomes, primarily due to hepatic metastasis. Colorectal cancer (CRC) cells have the ability to secrete cytokines and other molecules that can remodel the tumor microenvironment, facilitating the spread of cancer to the liver. Kupffer cells (KCs), which are macrophages in the liver, can be polarized to M2 type, thereby promoting the expression of adhesion molecules that aid in tumor metastasis. Our research has shown that huachanshu (with bufalin as the main active monomer) can effectively inhibit CRC metastasis. However, the underlying mechanism still needs to be thoroughly investigated. We have observed that highly metastatic CRC cells have a greater ability to induce M2-type polarization of Kupffer cells, leading to enhanced metastasis. Interestingly, we have found that inhibiting the expression of IL-6, which is highly expressed in the serum, can reverse this phenomenon. Notably, bufalin has been shown to attenuate the M2-type polarization of Kupffer cells induced by highly metastatic Colorectal cancer (mCRC) cells and down-regulate IL-6 expression, ultimately inhibiting tumor metastasis. In this project, our aim is to study how high mCRC cells induce M2-type polarization and how bufalin, via the SRC-3/IL-6 pathway, can inhibit CRC metastasis. This research will provide a theoretical foundation for understanding the anti-CRC effect of bufalin.

Inhibitory Impact Of Cinobufagin In Triple-Negative Breast Cancer Metastasis: Involvements Of Macrophage Reprogramming Through Upregulated MME and Inactivated FAK/STAT3 Signaling.

BACKGROUND: Cinobufagin (CBG), a key bioactive component in cinobufacini, exhibits antitumor properties. This study explores CBG's impact on triple-negative breast cancer (TNBC) metastasis and elucidates the underpinning mechanism. METHODS: Murine xenograft and orthotopic metastatic TNBC models were generated and treated with CBG. The burden of metastatic tumor in the mouse lung, the epithelial to mesenchymal transition (EMT) markers, and macrophage polarization markers within the tumors were examined. The phenotype of tumor-associated macrophages (TAMs) and mobility of TNBCs in vitro in a macrophage-TNBC cell coculture system were analyzed. Physiological targets of CBG were identified by bioinformatics analyses. RESULTS: CBG treatment significantly alleviated lung tumor burden and EMT activity. It triggered an M2-to-M1 shift in TAMs, resulting in decreased TNBC cell migration, invasion, and EMT in vitro. CBG upregulated membrane metalloendopeptidase (MME) expression, suppressing FAK and STAT3 phosphorylation. Silencing of MME, either in mice or TAMs, counteracted CBG effects, reinstating M2 TAM predominance and enhancing TNBC cell metastasis. Cotreatment with Defactinib, a FAK antagonist, reversed M2 TAM polarization and TNBC cell metastasis. Notably, MME silencing in TNBC cells had no impact on CBG-suppressed malignant properties, indicating MME's indirect involvement in TNBC cell behavior through TAM mediation. CONCLUSION: This study unveils CBG's ability to enhance MME expression, deactivate FAK/STAT3 signaling, and inhibit TNBC metastasis by suppressing M2-skewed macrophages.

Chemical Composition, Pharmacological Effects and Clinical Applications of Cinobufacini.

Chinese medicine cinobufacini is an extract from the dried skin of Bufo bufo gargarizans Cantor, with active ingredients of bufadienolides and indole alkaloids. With further research and clinical applications, it is found that cinobufacini alone or in combination with other therapeutic methods can play an anti-tumor role by controlling proliferation of tumor cells, promoting apoptosis, inhibiting formation of tumor neovascularization, reversing multidrug resistance, and regulating immune response; it also has the functions of relieving cancer pain and regulating immune function. In this paper, the chemical composition, pharmacological effects, clinical applications, and adverse reactions of cinobufacini are summarized. However, the extraction of monomer components of cinobufacini, the relationship between different mechanisms, and the causes of adverse reactions need to be further studied. Also, high-quality clinical studies should be conducted.

Bufotalin attenuates pulmonary fibrosis via inhibiting Akt/GSK-3ß/ß-catenin signaling pathway.

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease with no cure. Bufotalin (BT), an active component extracted from Venenum Bufonis, has been prescribed as a treatment for chronic inflammatory diseases. However, whether BT has antifibrotic properties has never been investigated. In this study, we report on the potential therapeutic effect and mechanism of BT on IPF. BT was shown to attenuate lung injury, inflammation, and fibrosis as well as preserve pulmonary function in bleomycin (BLM)-induced pulmonary fibrosis model. We next confirmed BT's ability to inhibit TGF-ß1-induced epithelial-mesenchymal transition (EMT) and myofibroblast activation (including differentiation, proliferation, migration, and extracellular matrix production) in vitro. Furthermore, transcriptional profile analysis indicated the Wnt signaling pathway as a potential target of BT. Mechanistically, BT effectively prevented ß-catenin from translocating into the nucleus to activate transcription of profibrotic genes. This was achieved by blunting TGF-ß1-induced increases in phosphorylated Akt Ser437 (p-Akt S437) and phosphorylated glycogen synthase kinase (GSK)-3ß Ser9 (p-GSK-3ß S9), thereby reactivating GSK-3ß. Additionally, the antifibrotic effects of BT were further validated in another in vivo model of radiation-induced pulmonary fibrosis. Collectively, these data demonstrated the potent antifibrotic actions of BT through inhibition of Akt/GSK-3ß/ß-catenin axis downstream of TGF-ß1. Thus, BT could be a potential option to be further explored in IPF treatment.

Pharmacological Effects of Cinobufagin.

Cinobufagin (CBF) is a bufadienolide, which is a major active ingredient of toad venom. In recent years, CBF has attracted increasing attention due to its highly potent and multiple pharmacological activities. To better understand the status of research on CBF, we collated recent studies on CBF to provide a valuable reference for clinical researchers and practitioners. According to reports, CBF exhibits extensive pharmacological properties, including antitumor, analgesic, cardioprotection, immunomodulatory, antifibrotic, antiviral, and antiprotozoal effects. Studies on the pharmacological activity of CBF have mainly focused on its anticancer activity. It has been demonstrated that CBF has a therapeutic effect on liver cancer, osteosarcoma, melanoma, colorectal cancer, acute promyelocytic leukemia, nasopharyngeal carcinoma, multiple myeloma, gastric cancer, and breast cancer. However, the direct molecular targets of CBF are currently unknown. In addition, there are few reports on toxicological and pharmacokinetic of CBF. Subsequent studies focusing on these aspects will help promote the development and application of CBF in clinical practice.

Bufalin serves as a pharmaceutic that mitigates drug resistance.

Intrinsic or acquired drug resistance of tumor cells is the main cause of tumor chemotherapy failure and tumor-related death. Bufalin (BF) is the main active monomer component extracted from the Traditional Chinese Medicine Toad venom (secretions of glands behind the ears and epidermis of bufo gargarizans and Bufo Melanostictus Schneider). It is a cardiotonic steroid with broad-spectrum anti-cancer effects and has been widely used against various malignant tumors in clinical practice. Pharmacological studies also found that BF has the effect of reversing drug resistance, which provides a new perspective for the application of Traditional Chinese Medicine as a chemosensitizer in cancer therapy. This article provides an extensive search and summary of published research on mitigating drug resistance to BF and reviews its potential mechanisms.

Resibufogenin, one of bufadienolides in toad venom, suppresses LPS-induced inflammation via inhibiting NF-κB and AP-1 pathways.

Toad venom is a traditional Chinese medicine that has a long history in treating infectious and inflammatory diseases, such as carbuncle, pharyngitis. As one of the major active components in toad venom, resibufogenin (RBG) possesses a variety of pharmacological activities, including lowering blood pressure, reducing proteinuria and preventing oxidative stress. But only its antitumor activity attracts widespread attention in these years. This study aimed to explore the nonnegligible anti-inflammatory activity of RBG in vivo and in vitro. In endotoxemia mice, a single intraperitoneal administration of RBG significantly lowered serum TNF-α, IL-6 and MCP-1 levels. In LPS-stimulated macrophages, RBG decreased LPS-induced pro-inflammatory mediators' productions (e.g., iNOS, IL-6, TNF-α and MCP-1) through suppressing their transcriptions. Mechanism study showed that RBG hindered IκBα phosphorylation and prevented nuclear translocation of p65, thus inactivating nuclear factor-κB (NF-κB) signaling. Concurrently, RBG also dampened activator protein-1 (AP-1) signaling through inhibiting the phosphorylation levels of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK). Besides LPS (TLR4 ligand) model, RBG also inhibited Pam3CSK4 (TLR2 ligand)- or poly I:C (TLR3 ligand)-induced inflammatory reactions, suggesting that its target(s) site is(are) not on the cytomembrane. These findings not only support the pharmacological basis for the traditional use of toad venom in inflammatory diseases, but also provide a promising anti-inflammatory candidate.

Bufalin for an innovative therapeutic approach against cancer.

Bufalin is an endogenous cardiotonic steroid, first discovered in toad venom but also found in the plasma of healthy humans, with anti-tumour activities in different cancer types. The current review is focused on its mechanisms of action and highlights its very large spectrum of effects both in vitro and in vivo. All leads to the conclusion that bufalin mediates its effects by affecting all the hallmarks of cancer and seems restricted to cancer cells avoiding side effects. Bufalin decreases cancer cell proliferation by acting on the cell cycle and inducing different mechanisms of cell death including apoptosis, necroptosis, autophagy and senescence. Bufalin also moderates metastasis formation by blocking migration and invasion as well as angiogenesis and by inducing a phenotype switch towards differentiation and decreasing cancer cell stemness. Regarding its various mechanisms of action in cancer cells, bufalin blocks overactivated signalling pathways and modifies cell metabolism. Moreover, bufalin gained lately a huge interest in the field of drug resistance by both reversing various drug resistance mechanisms and affecting the immune microenvironment. Together, these data support bufalin as a quite promising new anti-cancer drug candidate.

AHSA1 is a promising therapeutic target for cellular proliferation and proteasome inhibitor resistance in multiple myeloma.

BACKGROUND: Currently, multiple myeloma (MM) is still an incurable plasma cell malignancy in urgent need of novel therapeutic targets and drugs. METHODS: Bufalin was known as a highly toxic but effective anti-cancer compound. We used Bufalin as a probe to screen its potential targets by proteome microarray, in which AHSA1 was the unique target of Bufalin. The effects of AHSA1 on cellular proliferation and drug resistance were determined by MTT, western blot, flow cytometry, immunohistochemistry staining and xenograft model in vivo. The potential mechanisms of Bufalin and KU-177 in AHSA1/HSP90 were verified by co-immunoprecipitation, mass spectrometry, site mutation and microscale thermophoresis assay. RESULTS: AHSA1 expression was increased in MM samples compared to normal controls, which was significantly associated with MM relapse and poor outcomes. Furthermore, AHSA1 promoted MM cell proliferation and proteasome inhibitor (PI) resistance in vitro and in vivo. Mechanism exploration indicated that AHSA1 acted as a co-chaperone of HSP90A to activate CDK6 and PSMD2, which were key regulators of MM proliferation and PI resistance respectively. Additionally, we identified AHSA1-K137 as the specific binding site of Bufalin on AHSA1, mutation of which decreased the interaction of AHSA1 with HSP90A and suppressed the function of AHSA1 on mediating CDK6 and PSMD2. Intriguingly, we discovered KU-177, an AHSA1 selective inhibitor, and found KU-177 targeting the same site as Bufalin. Bufalin and KU-177 treatments hampered the proliferation of flow MRD-positive cells in both primary MM and recurrent MM patient samples. Moreover, KU-177 abrogated the cellular proliferation and PI resistance induced by elevated AHSA1, and decreased the expression of CDK6 and PSMD2. CONCLUSIONS: We demonstrate that AHSA1 may serve as a promising therapeutic target for cellular proliferation and proteasome inhibitor resistance in multiple myeloma.

Small molecule targeting topoisomerase 3ß for cancer therapy.

DNA topoisomerases are proved cancer therapeutic targets with clinically successful anticancer drugs for decades. However, the role of RNA topoisomerase (TOP3ß) remained mysterious especially in cancer, and no targeted agent has been reported yet. In a target identification assay of anti-cancer compound using a modified DrugTargetSeqR strategy, mutation of TOP3B was detected in cancer cells acquired resistance to cinobufagin (CBG), a key compound of Huachansu that has been approved for cancer therapy in China. We demonstrated that CBG directly engaged with TOP3ß, and promoted TOP3ß depletion in wildtype but not mutant cancer cells. Notably, knockout of TOP3ß in cancer cells significantly reduced tumor enlargement but not initiation, and inhibited colony formation upon nutrient deprivation. We also demonstrated that CBG induced formation of stress granule, RNA-loop and asymmetric DNA damages in cancer cells, and all these phenotypes were significantly attenuated in TOP3B knockout cells. Of note, examination of a panel of cancer cell lines revealed associations among cell growth inhibition and induction of DNA damage as well as TOP3B depletion upon CBG treatment. Our findings not only highlighted TOP3ß as a promising therapeutic target of cancer, but also identified CBG as a lead chemical inhibitor of TOP3ß for cancer therapy.

Novel SREBP1 inhibitor cinobufotalin suppresses proliferation of hepatocellular carcinoma by targeting lipogenesis.

Hepatocellular carcinoma (HCC) is the major type of primary liver cancer and a leading cause of cancer-related deaths worldwide. Cinobufotalin (CBF) is extracted from the skin secretion of the giant toad and clinically used for the treatment of liver cancer, but its molecular mechanism of anti-cancer in HCC has not yet been elucidated. Here, we showed CBF effectively promoted cell apoptosis, induced cell cycle G2-M arrest, inhibited cell proliferation and lipogenesis. Consistently, the lipogenesis ability of xenograft examined by 11C-acetate micro-PET/CT imaging, and the tumor growth rate was notably declined in a centration-dependent manner. The fatty acid profiles showed saturated and mono-unsaturated fatty acid significantly decreased after CBF treatment. Mechanistically, CBF selectively inhibited the expression of SREBP1 and interacted with SREBP1 to prevent it from sterol regulatory elements (SREs), thus inhibiting the expression of lipogenic enzymes. Collectively, our study demonstrates that CBF is a potent native compound that remarkably inhibits HCC lipogenesis and tumorigenesis. CBF may possess this therapeutic potential though interfering with de novo lipid synthesis via SREBP1.

Bufalin targets the SRC-3/MIF pathway in chemoresistant cells to regulate M2 macrophage polarization in colorectal cancer.

M2-polarized macrophages are one of critical factors in tumour chemoresistance. An increasing number of studies have shown that M2 macrophage polarization can be promoted by chemoresistance. A large number of evidences indicate that Bufalin has significant antitumour effect, previous studies have found that Bufalin can reduce the polarization of M2 macrophages to play an anti-tumour effect in vivo, but the mechanism remains unclear. In our study, we found that Bufalin reduced the polarization of M2 macrophages induced by chemoresistant cells both in vivo and in vitro; however, Bufalin had no obvious direct effect on M2 macrophage polarization. Furthermore, we demonstrated that Bufalin targeted the SRC-3 protein to reduce MIF release in chemoresistant cells in order to regulate the polarization of M2 macrophages. More interestingly, we also found that Cinobufacini, Bufalin is its main active monomer, which its could regulate the polarization of M2 macrophages to enhance the anti-tumour effect of oxaliplatin in vivo and in the clinic. Overall, this study provides a theoretical basis for the clinical application of drugs containing Bufalin as the main active ingredient in combination with established chemotherapy for the treatment of colorectal cancer.

Therapeutic potential of targeting membrane-spanning proteoglycan SDC4 in hepatocellular carcinoma.

Syndecan-4 (SDC4) functions as a major endogenous membrane-associated receptor and widely regulates cytoskeleton, cell adhesion, and cell migration in human tumorigenesis and development, which represents a charming anti-cancer therapeutic target. Here, SDC4 was identified as a direct cellular target of small-molecule bufalin with anti-hepatocellular carcinoma (HCC) activity. Mechanism studies revealed that bufalin directly bond to SDC4 and selectively increased SDC4 interaction with substrate protein DEAD-box helicase 23 (DDX23) to induce HCC genomic instability. Meanwhile, pharmacological promotion of SDC4/DDX23 complex formation also inactivated matrix metalloproteinases (MMPs) and augmented p38/JNK MAPKs phosphorylation, which are highly associated with HCC proliferation and migration. Notably, specific knockdown of SDC4 or DDX23 markedly abolished bufalin-dependent inhibition of HCC proliferation and migration, indicating SDC4/DDX23 signaling axis is highly involved in the HCC process. Our results indicate that membrane-spanning proteoglycan SDC4 is a promising druggable target for HCC, and pharmacological regulation of SDC4/DDX23 signaling axis with small-molecule holds great potential to benefit HCC patients.

A hybrid membrane coating nanodrug system against gastric cancer via the VEGFR2/STAT3 signaling pathway.

Although drug combination has proved to be an efficient strategy for clinic gastric cancer therapy, how to further improve their bioavailability and reduce the side effects are still challenges due to the low solubility and untargeted ability of drugs. Recently, newly emerging nanotechnology has provided an alternative for constructing new drug delivery systems with high targeting ability and solubility. In this study, a pH-responsive liposome (Liposome-PEO, LP) loaded with apatinib (AP) and cinobufagin (CS-1) was used for combinational therapy against gastric cancer after coating with a hybrid membrane (R/C). The results indicated that the constructed nanocomplex LP-R/C@AC not only efficiently killed tumor cells in vitro by inducing apoptosis, autophagy, and pyroptosis, but also significantly inhibited tumor invasion and metastasis via the VEGFR2/STAT3 pathway. Moreover, it showed stronger anti-tumor activity in gastric cancer-bearing mouse models, as compared to the sole drugs. A naturally-derived hybrid cell membrane coating bestowed nanocomplexes with enhanced biointerfacing including prolonged circulation time and targeting ability.

Bufothionine induces autophagy in H22 hepatoma-bearing mice by inhibiting JAK2/STAT3 pathway, a possible anti-cancer mechanism of cinobufacini.

ETHNOPHARMACOLOGICAL RELEVANCE: Cinobufacini is extracted from the skins and parotid venom glands of the toad for treating symptoms like swelling and pain in ancient times. Nowadays, cinobifucini injection has also achieved satisfactory therapeutic effects on hepatocellular carcinoma (HCC) in China. AIM OF THE STUDY: Our previous work found that bufothionine, an alkaloid abundant in cinobufacini injection, induced mitochondria-mediated apoptosis. In this work, the underlying effects of bufothionine on autophagy in HCC and its possible dependent pathway were investigated. METHODS: CCK-8 and Hoechst staining assays were performed to verify effects of drugs on proliferation and apoptosis of SMMC7721 cell. H22-tumor-bearing mice model was established by inoculating ascites fluid. HE staining was used to observe pathological changes in liver and tumor tissues. ELISA and Western blot experiments were conducted to investigate IL-6/JAK2/STAT3 signaling pathway. The effects of drugs on expressions of autophagic relative proteins were investigated by Western blot in vitro and in vivo. RESULTS: In vitro, CCK-8 and Hoechst staining assays showed that bufothionine inhibited SMMC7721 cell proliferation and promoted apoptosis at 100 µM. In vivo, bufothionine relieved symptoms of H22-tumor-bearing mice and exerted anti-inflammation activity. ELISA and Western blot demonstrated that bufothionine significantly reduced serum IL-6 concentration, suppressed p-Stat3tyr705, p-Stat3ser727 and Jak2 expressions in tumor tissues and upregulated Atg5, Atg7 and LC3Ⅱ expressions in SMMC7721 cell and H22 tumor. CONCLUSION: This is the first report showing that bufothionine might induce autophagy in HCC by inhibiting JAK2/STAT3 pathway, presenting a possible anti-cancer mechanism of bufothionine in cinobufacini injection.

Bufarenogin induces intrinsic apoptosis via Bax and ANT cooperation.

Toads have high medicinal value and have been used for medicinal purposes since the Tang Dynasty period (7th-10th Century AD). Bufarenogin, an active anti-tumor constituent of toad venom, shows anti-tumor activity. In this study, we investigated the inhibitory effects of bufarenogin on the growth and metastasis of colorectal cancer (CRC), particularly its effects on mediating intrinsic signaling pathways that initiate apoptosis. An orthotopic CRC model was established in nude mice via surgical orthotopic implantation to investigate tumor growth. Immunohistochemistry, immunofluorescence, and Western blotting assays were performed to evaluate protein expression. The in vitro results revealed the anti-proliferative effect of bufarenogin against CRC cells. Bufarenogin caused cell death via apoptosis, as revealed by Annexin V/7-amino-actinomycin D double staining, which was verified using a pan-caspase inhibitor. Bufarenogin induced B-cell lymphoma 2-associated X protein (Bax)-dependent intrinsic apoptosis, as demonstrated by mitochondrial translocation of Bax and cytoplasm release of HCT116 wild-type cells and cytochrome C (soluble pro-apoptotic factors). Additionally, we showed that adenine-nucleotide translocator interacted with Bax. Bufarenogin induced intrinsic apoptosis through the cooperation of Bax and adenine-nucleotide translocator and inhibited the metastasis and growth of orthotopical CRC cells.

Bersaldegenin-1,3,5-orthoacetate induces caspase-independent cell death, DNA damage and cell cycle arrest in human cervical cancer HeLa cells.

CONTEXT: Bufadienolide compounds occur in many plants and animal species and have strong cardiac and anti-inflammatory properties. The compounds have been recently investigated for cytotoxic and antitumor activity. OBJECTIVE: The cytotoxic effect of bersaldegenin-1,3,5-orthoacetate - a bufadienolide steroid occuring in plants from Kalanchoe genus (Crassulaceae), was evaluated with cervical cancer HeLa cells in vitro. MATERIALS AND METHODS: The cytotoxic activity of the compound (at 0.1-20.0 µg/mL) on the cells was determined by Real-Time Cell Analysis (RTCA) system for 24 h. The estimation of cell cycle arrest, reactive oxygen species (ROS) production, reduction of mitochondrial membrane potential (MMP), and caspases-3/7/9 activity in the HeLa cells treated with the compound was done by flow cytometry and luminometric technique. DNA damage in the cells was estimated by immunofluorescence staining and the comet assay with etoposide as a positive control. RESULTS: The compound had strong effect on the cells (IC50 = 0.55 µg/mL) by the suppression of HeLa cells proliferation in G2/M phase of cell cycle and induction of cell death through double-stranded DNA damage and reactive oxygen species overproduction. Furthermore, we did not observe an increase in the activity of caspase-3/7/9 in the treated cells as well as a decrease in cellular mitochondrial membrane potential. Gene expression analysis revealed the overexpression of NF-Kappa-B inhibitors genes (>2-fold higher than control) in the treated cells. CONCLUSIONS: Bersaldegenin-1,3,5-orthoacetate induces cell cycle arrest and caspase-independent cell death through double-stranded DNA damage. These results are an important step in further studies on cell death signalling pathways induced by bufadienolides.