Toad venom bufadienolides and bufotoxins: An updated review.

Bufadienolides, naturally found in toad venoms having steroid-like structures, reveal antiproliferative effects at low doses. However, their application as anticancer drugs is strongly prevented by their Na+ /K+ -ATPase binding activities. Although several kinds of research were dedicated to moderating their Na+ /K+ -ATPase binding activity, still deeper fundamental knowledge is required to bring these findings into medical practice. In this work, we reviewed data related to anticancer activity of bufadienolides such as bufalin, arenobufagin, bufotalin, gamabufotalin, cinobufotalin, and cinobufagin and their derivatives. Bufotoxins, derivatives of bufadienolides containing polar molecules mainly belonging to argininyl residues, are reviewed as well. The established structures of bufotoxins have been compiled into a one-page figure to review their structures. We also highlighted advances in the structure-modification of the structure of compounds in this class. Drug delivery approaches to target these compounds to tumor cells were discussed in one section. The issues related to extraction, identification, and quantification are separated into another section.

Enhanced Cytotoxic Effects of Arenite in Combination with Active Bufadienolide Compounds against Human Glioblastoma Cell Line U-87.

The cytotoxicity of a trivalent arsenic derivative (arsenite, AsIII) combined with arenobufagin or gamabufotalin was evaluated in human U-87 glioblastoma cells. Synergistic cytotoxicity with upregulated intracellular arsenic levels was observed, when treated with AsIII combined with arenobufagin instead of gamabufotalin. Apoptosis and the activation of caspase-9/-8/-3 were induced by AsIII and further strengthened by arenobufagin. The magnitude of increase in the activities of caspase-9/-3 was much greater than that of caspase-8, suggesting that the intrinsic pathway played a much more important role in the apoptosis. An increase in the number of necrotic cells, enhanced LDH leakage, and intensified G2/M phase arrest were observed. A remarkable increase in the expression level of γH2AX, a DNA damage marker, was induced by AsIII+arenobufagin. Concomitantly, the activation of autophagy was observed, suggesting that autophagic cell death associated with DNA damage was partially attributed to the cytotoxicity of AsIII+arenobufagin. Suppression of Notch signaling was confirmed in the combined regimen-treated cells, suggesting that inactivation of Jagged1/Notch signaling would probably contribute to the synergistic cytotoxic effect of AsIII+arenobufagin. Given that both AsIII and arenobufagin are capable of penetrating into the blood-brain barrier, our findings may provide fundamental insight into the clinical application of the combined regimen for glioblastoma.

Gamabufotalin inhibits colitis-associated colorectal cancer by suppressing transcription factor STAT3.

Constitutive activation of STAT3 plays important role in the pathogenesis of colorectal cancer (CRC). Inhibition of STAT3 has been proposed as a reasonable strategy to suppress CRC. Gamabufotalin (Gam), an effective bioactive compound of ChanChu, has been used for cancer therapy due to its desirable metabolic stability and less adverse effect. However, its effect on CRC is still unclear. In this study, we found that Gam significantly inhibited the CRC in vitro and vivo. Furthermore, Gam induced apoptosis to inhibit the viability of HCT-116 and HT-29 cell lines in dose-dependent manner by suppressing the transcription factor STAT3. In addition, Gam was also found to inhibit carcinogenesis of colitis-associated cancer (CAC) in AOM/DSS mice model by inhibiting STAT3. Our findings suggest that Gam may be an effective way to prevent occurrence and development of CRC and CAC.

Gamabufotalin loaded micro-nanocomposites for multimodal therapy of metastatic TNBC by efficiently inducing ICD.

Gamabufotalin (CS-6), a main active compound derived from Chinese medicine Chansu, exhibits a robust inhibitory effect on programmed death-ligand 1 (PD-L1) in triple-negative breast cancer (TNBC) cells. Despite its potential for tumor therapy, the medical application of CS-6 is constrained by its hydrophobic nature, lack of targeting capability, and weak immunogenic cell death (ICD) effect. To address these limitations and improve the therapeutic efficiency of this drug against metastatic TNBC, we designed a new kind of CS-6@CPB-S.lux that integrates carboxy-Prussian blue nanoparticles (CPB NPs), CS-6, and attenuated Salmonella typhimurium (S.lux) for TNBC therapy. In vitro and in vivo results have confirmed that CS-6@CPB NPs were efficiently delivered to neoplastic tissue by the tumor hypoxic chemotaxis property of S.lux, wherein the nanomedicine induced significant tumor cell necroptosis and apoptosis via photothermal therapy (PTT) of CPB NPs and chemotherapy of CS-6, which elicited ICD and inhibited PD-L1 expression, resulting in dendritic cells (DCs) maturation and effector T cells activation to comprehensively eliminate tumors. Additionally, the CS-6@CPB-S.lux + Laser treatment significantly transformed the immunosuppressive tumor microenvironment (TME), enhancing antitumor immunity through promoting the polarization of tumor-associated macrophages into antitumorigenic M1 and reducing Tregs recruitment. Consequently, this comprehensive therapy not only inhibited primary and abscopal tumor progression but also prevented TNBC metastasis, which significantly prolonged survival time in animal models. In summary, these findings indicated an alternative approach for metastatic TNBC therapy.

Apatinib and gamabufotalin co-loaded lipid/Prussian blue nanoparticles for synergistic therapy to gastric cancer with metastasis.

Due to the non-targeted release and low solubility of anti-gastric cancer agent, apatinib (Apa), a first-line drug with long-term usage in a high dosage often induces multi-drug resistance and causes serious side effects. In order to avoid these drawbacks, lipid-film-coated Prussian blue nanoparticles (PB NPs) with hyaluronan (HA) modification was used for Apa loading to improve its solubility and targeting ability. Furthermore, anti-tumor compound of gamabufotalin (CS-6) was selected as a partner of Apa with reducing dosage for combinational gastric therapy. Thus, HA-Apa-Lip@PB-CS-6 NPs were constructed to synchronously transport the two drugs into tumor tissue. In vitro assay indicated that HA-Apa-Lip@PB-CS-6 NPs can synergistically inhibit proliferation and invasion/metastasis of BGC-823 cells via downregulating vascular endothelial growth factor receptor (VEGFR) and matrix metalloproteinase-9 (MMP-9). In vivo assay demonstrated strongest anti-tumor growth and liver metastasis of HA-Apa-Lip@PB-CS-6 NPs administration in BGC-823 cells-bearing mice compared with other groups due to the excellent penetration in tumor tissues and outstanding synergistic effects. In summary, we have successfully developed a new nanocomplexes for synchronous Apa/CS-6 delivery and synergistic gastric cancer (GC) therapy.

Biomimetic nanoparticles loading with gamabutolin-indomethacin for chemo/photothermal therapy of cervical cancer and anti-inflammation.

A pro-nanodrug combinational strategy for efficient cervical cancer therapy with intrinsic tumor microenvironment (TME)-responsive elements and low side effects is highly desired. Here, a pro-nanodrug complexes with GSH and NIR responsive manner is reported to boost gamabufotalin induced chemo-photothermal therapy with the assistance of reprogrammed TME by indomethacin. In addition, hybrid cell membrane was used to endow nanocomplexes with the prolonging circulation time and high accumulation of drug at tumor tissue. Indomethacin activated by the high level GSH can attenuate tumor inflammation microenvironment triggered by PTT and sensitize tumor cells to gamabufotalin through inhibiting PGE2 secretion. The released low-dose gamabufotalin with low side effects can efficiently kill tumor cells by ROS production and COX-2 low expression. In vitro and in vivo assays demonstrated that strong anti-tumor activity of nanocomplexes in tumor-bearing mice through chemo-photothermal therapy, which was reflected by the eradication of cervical tumor and significant extension of survival time of mice.

Corrigendum: Cytotoxic Effects of Arsenite in Combination With Gamabufotalin Against Human Glioblastoma Cell Lines.

[This corrects the article DOI: 10.3389/fonc.2021.628914.].

Cytotoxic Effects of Arsenite in Combination With Gamabufotalin Against Human Glioblastoma Cell Lines.

Glioblastoma is a fatal primary malignant brain tumor, and the 5-year survival rate of treated glioblastoma patients still remains <5%. Considering the sustained development of metastasis, tumor recurrence, and drug resistance, there is an urgent need for the novel therapeutic approaches to combat glioblastoma. Trivalent arsenic derivative (arsenite, AsIII) with remarkable clinical efficacy in leukemia has been shown to exert cytocidal effect against glioblastoma cells. Gamabufotalin, an active bufadienolide compound, also shows selective cytocidal effect against glioblastoma cells, and has been suggested to serve as a promising adjuvant therapeutic agent to potentiate therapeutic effect of conventional anticancer drugs. In order to gain novel insight into therapeutic approaches against glioblastoma, the cytotoxicity of AsIII and gamabufotalin was explored in the human glioblastoma cell lines U-87 and U-251. In comparison with U-251 cells, U-87 cells were highly susceptible to the two drugs, alone or in combination. More importantly, clinically achieved concentrations of AsIII combined with gamabufotalin exhibited synergistic cytotoxicity against U-87 cells, whereas showed much less cytotoxicity to human normal peripheral blood mononuclear cells. G2/M cell cycle arrest was induced by each single drug, and further augmented by their combination in U-87 cells. Downregulation of the expression levels of cdc25C, Cyclin B1, cdc2, and survivin was observed in U-87 cells treated with the combined regimen and occurred in parallel with G2/M arrest. Concomitantly, lactate dehydrogenase leakage was also observed. Intriguingly, SB203580, a specific inhibitor of p38 MAPK, intensified the cytotoxicity of the combined regimen in U-87 cells, whereas wortmannin, a potent autophagy inhibitor, significantly rescued the cells. Collectively, G2/M arrest, necrosis and autophagy appeared to cooperatively contribute to the synergistic cytotoxicity of AsIII and gamabufotalin. Given that p38 MAPK serves an essential role in promoting glioblastoma cell survival, developing a possible strategy composed of AsIII, gamabufotalin, and a p38 MAPK inhibitor may provide novel insight into approaches designed to combat glioblastoma.

Gamabufotalin Inhibits Osteoclastgenesis and Counteracts Estrogen-Deficient Bone Loss in Mice by Suppressing RANKL-Induced NF-κB and ERK/MAPK Pathways.

Osteolytic bone disease is a condition of imbalanced bone homeostasis, characterized mainly by excessive bone-resorptive activity, which could predispose these populations, such as the old and postmenopausal women, to developing high risk of skeletal fragility and fracture. The nature of bone homeostasis is the coordination between the osteoblasts (OBs) and osteoclasts (OCs). Abnormal activation of osteoclasts (OCs) could compromise the bone homeostasis, constantly followed by a clutch of osteolytic diseases, including postmenopausal osteoporosis, osteoarthritis, and rheumatoid arthritis. Thus, it is imperatively urgent to explore effective medical interventions for patients. The traditional Chinese medicine (TCM) gamabufotalin (CS-6) is a newly identified natural product from Chansu and has been utilized for oncologic therapies owing to its good clinical efficacy with less adverse events. Previous study suggested that CS-6 could be a novel anti-osteoporotic agent. Nevertheless, whether CS-6 suppresses RANK-(receptor activator of nuclear factor-κ B ligand)/TRAF6 (TNF receptor-associated factor 6)-mediated downstream signaling activation in OCs, as well as the effects of CS-6 on OC differentiation in vivo, remains elusive. Therefore, in this present study, we aimed to explore the biological effects of CS-6 on osteoclastogenesis and RANKL-induced activation of related signaling pathways, and further to examine the potential therapeutic application in estrogen-deficient bone loss in the mice model. The results of in vitro experiment showed that CS-6 can inhibit RANKL-induced OC formation and the ability of bone resorption in a dose-dependent manner at both the early and late stages of osteoclastogenesis. The gene expression of OC-related key genes such as tartrate-resistant acid phosphatase (TRAP), CTSK, DC-STAMP, MMP9, and ß3 integrin was evidently reduced. In addition, CS-6 could mitigate the systemic estrogen-dependent bone loss and pro-inframammary cytokines in mice in vivo. The molecular mechanism analysis suggested that CS-6 can suppress RANKL/TRAF6-induced early activation of NF-κB and ERK/MAPK signaling pathways, which consequently suppressed the transcription activity of c-Fos and NFATc1. Taken together, this present study provided ample evidence that CS-6 has the promise to become a therapeutic candidate in treating osteolytic conditions mediated by elevated OC formation and bone resorption.

Gamabufotalin induces a negative feedback loop connecting ATP1A3 expression and the AQP4 pathway to promote temozolomide sensitivity in glioblastoma cells by targeting the amino acid Thr794.

OBJECTIVES: Temozolomide (TMZ) is one of the most commonly used clinical drugs for glioblastoma (GBM) treatment, but its drug sensitivity needs to be improved. Gamabufotalin (CS-6), the primary component of the traditional Chinese medicine "ChanSu," was shown to have strong anti-cancer activity. However, more efforts should be directed towards reducing its toxicity or effective treatment doses. METHODS: Target fishing experiment, Western blotting, PCR, confocal immunofluorescence and molecular cloning techniques were performed to search for possible downstream signalling pathways. In addition, GBM xenografts were used to further determine the potential molecular mechanisms of the synergistic effects of CS-6 and TMZ in vivo. RESULTS: Mechanistic research revealed a negative feedback loop between ATP1A3 and AQP4 through which CS-6 inhibited GBM growth and mediated the synergistic treatment effect of CS-6 and TMZ. In addition, by mutating potential amino acid residues of ATP1A3, which were predicted by modelling and docking to interact with CS-6, we demonstrated that abrogating hydrogen bonding of the amino acid Thr794 interferes with the activation of ATP1A3 by CS-6 and that the Thr794Ala mutation directly affects the synergistic treatment efficacy of CS-6 and TMZ. CONCLUSIONS: As the main potential target of CS-6, ATP1A3 activation critically depends on the hydrogen bonding of Thr794 with CS-6. The combination of CS-6 and TMZ could significantly reduce the therapeutic doses and promote the anti-cancer efficacy of CS-6/TMZ monotherapy.

Sequentially-targeted biomimetic nano drug system for triple-negative breast cancer ablation and lung metastasis inhibition.

As a breast cancer subtype with high mortality in women, the efficient treatment of Triple-negative breast cancer (TNBC) is still a challenge due to its unique metastatic mode and poor prognosis. In this study, we developed a biomimetic nanodelivery system (denoted as GTDC@M-R NPs) based on erythrocyte membrane (M)-camouflaged graphene oxide quantum dots (GOQDs, G) for TNBC therapy. The TAT (T) and RGD (R) peptides were used to endow targeting accumulation ability of Gamabufotalin (CS-6, C) and doxorubicin (DOX, D) in tumor tissue. In vitro assay indicated good biocompatibility, prolonged blood circulation time (3-fold longer than GT NPs), and effectively enhanced cell and nucleus targeting capability of this nanosystem. Fluorescence activated cell sorter (FACS) analysis indicated that the combination of DOX and CS-6 induced TNBC cell apoptosis more than 89 % under the ratio of 10:1. In vivo assay indicated that the accumulation of GTDC@M-R NPs in tumor sites increased about 2-fold compared to naked GTDC NPs, which was accompanied by high tumor apoptosis rates through blocking chemotherapy-activated cyclooxygenase-2 (COX-2) and enhancing DOX's anti-tumor activity of chemical drugs (85%). Moreover, comparing with the control, the average number of lung metastatic nodules in tumor-bearing mice reduced 84%, the molecular mechanism of which is related to the down expression of COX-2, matrix metalloproteinase 9 (MMP9) and vascular endothelial growth factor (VEGF). Taken together, our results proved that the developed GTDC@M-R NPs can inhibit the growth and suppress metastasis of TNBC, which broaden our insights into the application of combinational strategy for efficient TNBC therapy. STATEMENT OF SIGNIFICANCE: In this study, we developed a biomimetic nanodelivery system (denoted as GTDC@M-R NPs) based on erythrocyte membrane (M)-camouflaged graphene oxide quantum dots (GOQDs, G) for TNBC therapy. The TAT (T) and RGD (R) peptides were used to endow targeting accumulation ability of Gamabufotalin (CS-6, C) and doxorubicin (DOX, D) in tumor tissue. These GTDC@M-R NPs indicated synergistic chemotherapy against TNBC cells through the precise cell and nuclear targeting, immune escape, and improved DOX sensitivity. A effective inhibition of tumor growth and metastasis was achieved by inhibiting Bcl-2/BAX, COX-2 and VEGF related signal pathways. Our finding suggests that the developed GTDC@M-R NPs present great treating effects in the preclinical models of TNBC, which broaden our insights into the application of combinational strategy for efficient TNBC therapy.

Multiple cytotoxic effects of gamabufotalin against human glioblastoma cell line U-87.

To provide novel insight into approaches designed to combat glioblastoma, the molecular details of the cytotoxicity of gamabufotalin, were investigated in the human glioblastoma cell line U-87. A dose-dependent cytotoxicity was observed in the cells, whereas no detectable toxicity was confirmed in mouse primary astrocytes. LDH leakage was only observed in the cells treated with a relatively high concentration (>80 ng/ml). Downregulation of the expression levels of Aurora B, cdc25A, cdc25C, cdc2, Cyclin B1 and survivin, and upregulation of the expression level of p21 were observed in treated cells and occurred in parallel with G2/M phase arrest. Treatment with gamabufotalin also downregulated the expression level of uPA, CA9, and upregulated the expression level of TIMP3, all of which are closely associated with invasion/metastasis. Autophagy induction was observed in the treated cells and the addition of wortmannin, a potent autophagy inhibitor, significantly rescued U-87 cells. These results indicate that gamabufotalin exhibits cytotoxicity against cancerous glial cells with high potency and selectivity through multiple cytotoxic signaling pathways. The activation of p38 MAPK pathway along with the upregulation of VEGF/VEGFR2 was observed in the treated cells, both of which are likely to be compensatory changes in response to gamabufotalin treatment. Intriguingly, a specific inhibitor of p38 MAPK enhanced the cytotoxicity of the drug, suggesting an important prosurvival role for p38 MAPK. We thus suggest that developing a new combination regimen of gamabufotalin plus a p38 MAPK inhibitor and/or inhibitors for VEGF/VEGFR could improve the efficacy of the drug, and may provide more therapeutic benefits to patients with glioblastoma.

In vitro phase I metabolism of gamabufotalin and arenobufagin: Reveal the effect of substituent group on metabolic stability.

Bufadienolides are a major class of bioactive compounds derived from amphibian skin secretion. Gamabufotalin (GB) and arenobufagin (AB) are among the top of the intensively investigated natural bufadienolides for their outstanding biological activities. This study aimed to characterize the phase I metabolism of GB and AB with respect to the metabolic profiles, enzymes involved, and catalytic efficacy, thereafter tried to reveal substituent effects on metabolism. Two mono-hydroxylated products of GB and AB were detected in the incubation mixtures, and they were accurately identified as 1- and 5-hydroxylated bufadienolides by NMR and HPLC-MS techniques. Reaction phenotyping studies demonstrated that CYP3A mediated the metabolism of the two bufadienolides with a high specific selectivity. Further kinetic evaluation demonstrated that the metabolism stability of GB and AB were better than other reported bufadienolides. Additionally, the CYP3A5 preference for hydroxylation of AB was observed, which was different to the selectivity of CYP3As for bufadienolides suggested by our previous report. This study can provide important data for elucidating the phase I metabolism of GB and AB and can lead to a better understanding of the bufadienolide-CYP3A interaction which is helpful for preclinical development and rational use of bufadienolides.

Gamabufotalin triggers c-Myc degradation via induction of WWP2 in multiple myeloma cells.

Deciding appropriate therapy for multiple myeloma (MM) is challenging because of the occurrence of multiple chromosomal changes and the fatal nature of the disease. In the current study, gamabufotalin (GBT) was isolated from toad venom, and its tumor-specific cytotoxicity was investigated in human MM cells. We found GBT inhibited cell growth and induced apoptosis with the IC50 values <50 nM. Mechanistic studies using functional approaches identified GBT as an inhibitor of c-Myc. Further analysis showed that GBT especially evoked the ubiquitination and degradation of c-Myc protein, thereby globally repressing the expression of c-Myc target genes. GBT treatment inhibited ERK and AKT signals, while stimulating the activation of JNK cascade. An E3 ubiquitin-protein ligase, WWP2, was upregulated following JNK activation and played an important role in c-Myc ubiquitination and degradation through direct protein-protein interaction. The antitumor effect of GBT was validated in a xenograft mouse model and the suppression of MM-induced osteolysis was verified in a SCID-hu model in vivo. Taken together, our study identified the potential of GBT as a promising therapeutic agent in the treatment of MM.

Mutations to the cardiotonic steroid binding site of Na(+)/K(+)-ATPase are associated with high level of resistance to gamabufotalin in a natricine snake.

Although toads are defended by bufadienolide toxins, some snakes have evolved resistance to bufadienolides and feed heavily on toads. We compared resistance in Nerodia rhombifer, which possesses mutations that confer target-site resistance, to Pituophis catenifer, which lacks those mutations. Even at the highest dosage tested, Nerodia showed no effects, whereas the lowest dose was lethal to Pituophis. Our results demonstrate a striking level of resistance to bufadienolides in a species possessing the mutations for resistance.

Quantitative proteomics reveals molecular mechanism of gamabufotalin and its potential inhibition on Hsp90 in lung cancer.

Gamabufotalin (CS-6) is a major bufadienolide of Chansu, which shows desirable metabolic stability and less adverse effect in cancer therapy. CS-6 treatment inhibited the proliferation of NSCLC in a nanomolar range. And CS-6 could induce G2/M cell cycle arrest and apoptosis in A549 cells. However, its molecular mechanism in antitumor activity remains poorly understood. We employed a quantitative proteomics approach to identify the potential cellular targets of CS-6, and found 38 possible target-related proteins. Among them, 31 proteins were closely related in the protein-protein interaction network. One of the regulatory nodes in key pathways was occupied by Hsp90. Molecular docking revealed that CS-6 interacted with the ATP-binding sites of Hsp90. In addition, CS-6 inhibited the chaperone function of Hsp90 and reduced expression of Hsp90-dependent client proteins. Moreover, CS-6 markedly down-regulated the protein level of Hsp90 in tumor tissues of the xenograft mice. Taken together, our results suggest that CS-6 might be a novel inhibitor of Hsp90, and the possible network associated with CS-6 target-related proteins was constructed, which provided experimental evidence for the preclinical value of using CS-6 as an effective antitumor agent in treatment of NSCLC.

Gamabufotalin, a major derivative of bufadienolide, inhibits VEGF-induced angiogenesis by suppressing VEGFR-2 signaling pathway.

Gamabufotalin (CS-6), a main active compound isolated from Chinese medicine Chansu, has been shown to strongly inhibit cancer cell growth and inflammatory response. However, its effects on angiogenesis have not been known yet. Here, we sought to determine the biological effects of CS-6 on signaling mechanisms during angiogenesis. Our present results fully demonstrate that CS-6 could significantly inhibit VEGF triggered HUVECs proliferation, migration, invasion and tubulogenesis in vitro and blocked vascularization in Matrigel plugs impregnated in C57/BL6 mice as well as reduced vessel density in human lung tumor xenograft implanted in nude mice. Computer simulations revealed that CS-6 interacted with the ATP-binding sites of VEGFR-2 using molecular docking. Furthermore, western blot analysis indicated that CS-6 inhibited VEGF-induced phosphorylation of VEGFR-2 kinase and suppressed the activity of VEGFR-2-mediated signaling cascades. Therefore, our studies demonstrated that CS-6 inhibited angiogenesis by inhibiting the activation of VEGFR-2 signaling pathways and CS-6 could be a potential candidate in angiogenesis-related disease therapy.

A Chinese patent medicine, Shexiang Baoxin Pill, for Non-ST-elevation acute coronary syndromes: A systematic review.

ETHNOPHARMACOLOGICAL RELEVANCE: Shexiang Baoxin Pill (SXBXP) is a well-known Chinese patent medicine, widely used for Non-ST-elevation acute coronary syndromes (NSTE-ACS). It is composed of seven materia medicas or extracts (Moschus, Radix Ginseng, Calculus Bovis, Cortex Cinnamomi, Styrax, Venenum Bufonis and Borneolum Syntheticum). AIM OF THE STUDY: This study is aimed to systematically review the relevant randomised controlled trials (RCTs) to determine the efficacy and safety of SXBXP for long-term management of NSTE-ACS. MATERIALS AND METHODS: A systematic review and meta-analysis were carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. All randomised controlled trials (RCTs) comparing long-term Shexiang Baoxin Pill with conventional treatment, with outcome measures relating to efficacy and safety were selected. Primary clinical outcome was the risk of cardiovascular events, secondary outcomes were hospitalizations, angina symptoms, electrocardiogram (ECG) measurements, and adverse events. RESULTS: Eleven RCTs recruiting 1389 patients were included, the overall risk of bias of the included trials is high and the quality poor. Compared with conventional treatment alone, long-term Shexiang Baoxin Pill plus conventional treatment might be more effective in lowering the risk of cardiovascular events (RR=0.36, 95% CI 0.26-0.49, <0.00001), hospitalizations (RR=0.38, 95% CI 0.21-0.67, P=0.0009), and improving angina symptoms (RR=1.19, 95% CI 1.13-1.26, P<0.00001), ECG measurements (RR=1.25, 95% CI 1.13-1.39, P<0.00001). Overall rate of adverse events was not elevated (P=0.43). CONCLUSIONS: From the available evidence, SXBXP added to conventional treatment may have beneficial effects on the long-term outcomes of NSTE-ACS, without serious adverse events. However, given the high risk of bias and low quality of the included trials, currently, there is no adequate evidence to draw any conclusions about its routine use. Large, methodologically-sound trials are needed to further assess its effects.

Pharmacokinetics and tissue distribution of five bufadienolides from the Shexiang Baoxin Pill following oral administration to mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Shexiang Baoxin Pill (SBP) is a well-known composite formula of traditional Chinese medicine (TCM), widely used to treat cardiovascular diseases such as angina pectoris and myocardial infarction. Bufadienolides are major active compounds of Venenum Bufonis, which is one of the seven materiamedicas that comprise the Shexiang Baoxin Pill. Previous pharmacokinetics studies of bufadienolides have typically used a single medicinal material delivered to rats. In this study, we have chosen the mouse, a more proper animal model than the rat, to investigate the in vivo pharmacokinetics and tissue distribution of bufadienolides from the Shexiang Baoxin Pill. MATERIALS AND METHODS: The concentrations of bufadienolides in plasma and tissues were identified using high performance liquid chromatography-tandem mass spectrometry (HPLC-ESI-MS/MS). The samples were prepared by liquid-liquid extraction with ethyl acetate, and the separation of bufadienolides was achieved using an ACQUITY HSS T3 column by gradient elution using water (containing 0.1% formic acid) and acetonitrile as the mobile phase at a flow rate of 0.3 mL/min. The pharmacokinetic parameters were determined using non-compartmental analysis. RESULTS: The results showed that the five bufadienolides were rapidly absorbed and distributed into the body. The pharmacokinetic curve showed double peaks after oral administration. The major tissue depots for resibufogenin, bufalin, and bufotalin in mice were the intestines, lung and kidney, whereas the major tissue depots of gamabufotalin and arenobufagin were the intestines, liver and kidney. CONCLUSION: The information gained from this research provides a meaningful insight for the clinical applications of the Shexiang Baoxin Pill.