Osthole inhibits the migration and invasion of highly metastatic breast cancer cells by suppressing ITGα3/ITGß5 signaling.

Metastasis is the leading cause of death in breast cancer patients. Osthole, as an active compound detected in the traditional Chinese medicine Wenshen Zhuanggu Formula, has shown a promising anti-metastatic activity in human breast cancer cells, but the underlying mechanisms remain ambiguous. In this study we elucidated the anti-metastatic mechanisms of osthole in highly metastatic breast cancer cells and a zebrafish xenograft model. We showed that the expression of integrin α3 (ITGα3) and integrin ß5 (ITGß5) was upregulated in highly metastatic MDA-MB-231, MDA-MB-231BO breast cancer cell lines but was downregulated in poorly metastatic MCF-7 breast cancer cell line, which might be the key targets of osthole's anti-metastatic action. Furthermore, we showed that knockdown of ITGα3 and ITGß5 attenuated breast cancer cell migration and invasion possibly via suppression of FAK/Src/Rac1 pathway, whereas overexpression of ITGα3 and ITGß5 caused the opposite effects. Consistently, osthole significantly inhibited breast cancer metastasis by downregulating ITGα3/ITGß5 signaling in vitro and in vivo. These results provide new evidence that osthole may be developed as a candidate therapeutic drug for metastatic breast cancer.

The Impact of Platinum-Containing Chemotherapies in Advanced Triple-Negative Breast Cancer: Meta-Analytical Approach to Evaluating Its Efficacy and Safety.

BACKGROUND: Triple-negative breast cancer (TNBC), the most common type of breast cancer, is associated with poor patient prognosis. Platinum-containing chemotherapies are commonly used in the treatment and prevention of advanced TNBC. OBJECTIVES AND METHODS: To systematically evaluate the effectiveness and safety of platinum-containing chemotherapies in patients with advanced TNBC, we searched several databases, including PubMed, Medline, Embase, ClinicalTrials.gov, Cochrane Library, CNKI, CBM, and the Chinese Cochrane Center, to collect published randomized controlled clinical studies of platinum-containing chemotherapies for advanced TNBC before November 2020. The meta-analysis was performed using Review Manager version 5.3. To assess effectiveness and safety, dichotomous and continuous variables were assessed using odds ratio (OR) and mean difference (MD), respectively, with 95% CI. RESULTS: A total of 1,222 patients with advanced TNBC were enrolled in 11 eligible trials, including 489 patients in the treatment group (platinum-containing) and 447 patients in the control group (non-platinum-containing). We also retrieved information whether a PARP inhibitor was combined with platinum-containing chemotherapy for patients with metastatic TNBC and identified 224 patients who received a PARP inhibitor combined with platinum-containing chemotherapy and 62 patients in the platinum-containing group who did not. The platinum-containing chemotherapy group had a significantly better objective response rate (OR 1.43, 95% CI 1.20-1.71, p < 0.001) and longer progression-free survival (PFS; MD 1.15, 95% CI 0.03-2.28, p < 0.05) than the non-platinum-containing chemotherapy group. However, there was no significant difference in overall survival (OS) of patients with advanced TNBC between the two groups (MD 2.04, 95% CI -0.83 to 4.91, p > 0.05). Related adverse effects of platinum-containing chemotherapies involved gastrointestinal reaction, myelosuppression and liver function damage. Platinum-containing chemotherapies were not associated with an increased incidence of adverse side effects compared with non-platinum-containing chemotherapies, with the exception of nausea and vomiting (OR 2.22, 95% CI 1.10-4.46, p < 0.05). Furthermore, the addition of the PARP inhibitor iniparib to gemcitabine and carboplatin treatment improved the rate of clinical benefit, OS and PFS. CONCLUSIONS: Platinum-containing chemotherapy remains a highly recommended therapeutic regimen due to greater effectiveness and tolerance for patients with advanced TNBC.

Proteomics analysis of tumor exosomes reveals vital pathways of Jinfukang inhibiting circulating tumor cells metastasis in lung cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Jinfukang has long been used for the clinical treatment of lung cancer. Previous studies have shown that Jinfukang can induce the apoptosis of circulating tumor cells by intervening ROS-mediated DNA damage pathway. However, whether Jinfukang can inhibit the metastasis of circulating tumor cells and its mechanism are still unclear. AIM OF THE STUDY: To further investigate the mechanism of Jinfukang in anti-metastasis of lung cancer from the perspective of intervention of tumor exosomes. MATERIALS AND METHODS: The invadopodia formation was determined with immunofluorescence. Invasion and migration were detected using the Transwell assay. Ultracentrifugation was used to isolate exosomes. Exosomes were characterized by electron microscopy, nanoparticle tracking analysis and immunoblotting, and the protein profile was evaluated by proteomic analysis. The molecular functions, biological processes and signaling pathway enrichment analysis were performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Key differentially expressed proteins were verified by Western blot. RESULTS: Jinfukang can inhibit the expression of MMP14, cortactin, Tks5 and the formation of invadopodia of CTC-TJH-01 cells. Furthermore, Jinfukang can significantly inhibit the invasion and migration of CTC-TJH-01 cells. The diameter of exosomes extracted from the CTC-TJH-01 cells treated by Jinfukang was 30-100 nm, and the exosomal markers CD63, CD81 and TSG101 were expressed. We identified 680 deferentially expressed proteins. Gene oncology analysis indicated that exosomes were mostly derived from plasma membrane and mainly involved in protein localization and intracellular signaling. The ingenuity pathway analysis showed that the EGF pathway was significantly inhibited, whereas the GP6 signaling pathway was significantly activated. We also confirmed that Jinfukang inhibited the expression of EGF pathway-related proteins in CTC-TJH-01 cells. Besides, when EGF was used to activate EGF signaling pathway, the inhibition of Jinfukang on CTC cell metastasis was reversed. CONCLUSION: Jinfukang inhibits the metastasis of CTC-TJH-01 cells through the EGF pathway.

Wenshen Zhuanggu formula effectively suppresses breast cancer bone metastases in a mouse Xenograft model.

Wenshen Zhuanggu formula (WSZG) is a traditional Chinese medicine used as an adjuvant for the prevention of bone metastases in breast cancer patients. In this study we investigated the efficacy of WSZG in preventing bone metastases and the potential mechanisms in a mouse xenograft model of breast cancer bone metastases. This model was established by injection of human MDA-MB-231BO-Luc breast cancer cells alone or a mixture of the cancer cells with bone marrow-derived mesenchymal stem cells (BMSCs) into left ventricle of the heart in female nude mice. Then the mice were treated with WSZG (3.25, 6.5 or 13.0 mg·kg-1·d-1, ig) for four weeks, whereas zoledronic acid (100 µg/kg per week, ig) was used as a positive control. The occurrence and development of bone metastases were monitored via bioluminescent imaging, and bone lesions were assessed using micro-CT. Intracardiac injection of the mixture of MDA-MB-231BO-Luc breast cancer cells with BMSCs significantly facilitated the bone metastatic capacity of the breast cancer cells, and aggravated bone lesions in the mouse xenograft model of breast cancer bone metastases. Administration of WSZG dose-dependently inhibited the incidence and intensity of bone metastases and protected against bone lesions by suppressing osteoclast formation and tumor cell infiltration. Furthermore, administration of WSZG caused a marked reduction in the expression of CCL5/CCR5 and IL-17B/IL-17BR in bone metastatic tissues. The results demonstrate that WSZG exerts potential therapeutic effects in a mouse xenograft model of breast cancer bone metastases, which are partially mediated by weakening the interaction between BMSCs and breast cancer cells in the tumor microenvironment.

Anti-metastatic effect and mechanisms of Wenshen Zhuanggu Formula in human breast cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Wenshen Zhuanggu Formula (WSZG), a traditional Chinese medicine (TCM) empirical prescription, has been used to treat the patients with breast cancer bone metastasis as an adjuvant in clinical practice. To explore the anti-metastatic activity and potential mechanisms of WSZG-containing serum (WSZG-CS) on highly bone-metastatic human breast cancer MDA-MB-231BO cells. MATERIALS AND METHODS: MDA-MB-231BO cells were cultured alone or co-cultured with bone marrow-derived mesenchymal stem cells (BMSCs). Invasion assays were carried out in Matrigel-coated Transwell chambers. CC chemokine 5 (CCL5) and interleukin (IL)-17B secretion levels were detected by ELISA. CCR5 and IL-17BR protein expression levels were determined by immunocytochemistry and Western blot analysis. RESULTS: Compared with control serum, WSZG-CS significantly inhibited BMSC induced MDA-MB-231BO breast cancer cell invasion, reduced CCL5 and IL-17B levels in co-culture supernatants, and downregulated CCR5 and IL-17BR protein expression in breast cancer cells co-cultured with BMSCs. CONCLUSIONS: WSZG-CS exerts an anti-metastatic activity against MDA-MB-231BO breast cancer cells, due to its ability to mitigate the interaction between BMSCs and breast cancer cells mediated via the CCL5/CCR5 and IL-17B/IL-17BR signaling pathways.

Relationships between pharmacokinetics and efficacy of Xie-xin decoction in rats with experimental ulcerative colitis.

ETHNOPHARMACOLOGICAL RELEVANCE: Xie-xin decoction (XXD) has been used as a classic formula in China for the treatment of gastrointestinal dysfunction such as ulcerative colitis (UC). However, no potential action mechanisms and active compounds had been systematically investigated. AIM OF THE STUDY: To explore the effectiveness and the material basis of XXD in trinitrobenzene sulfonic acid (TNBS)-induced UC rats. MATERIALS AND METHODS: XXD was administered orally for 8 days at a dosage of 2 or 4g/kg/day. Plasma pharmacokinetic properties and colon tissue concentrations of multiple compounds from XXD were detected. Tissue damage scores, production of interleukin (IL)-10 and myeloperoxidase (MPO), expression of tumor necrosis factor-alpha (TNF-α) and nuclear factor-kappa Bp65 (NF-κBp65) in colon tissues were examined. Canonical correlation analysis was performed to evaluate the relationships between pharmacokinetics and efficacy to elucidate significantly active compounds of XXD. RESULTS: XXD promoted the recovery of colitis and inhibited the colonic inflammation damage in UC rats by reducing the level of MPO and the expression of TNF-α and NF-κBp65, and increasing the production of IL-10 in colon tissues. Efficacy of XXD was positively related with AUC of five plasma compounds (baicalin, berberine, wogonoside, wogonin, and rhein) and concentrations of six colon tissue compounds (coptisine, jatrorrhizine, palmatine, berberine, baicalein and emodin), respectively. CONCLUSIONS: The multiple compounds in plasma and colon tissues from XXD might be the main material basis for therapeutic potentials in UC rats.

[Effects of platycodin D in combination with different active ingredients of Chinese herbs on proliferation and invasion of 4T1 and MDA-MB-231 breast cancer cell lines].

OBJECTIVE: To investigate the effects of platycodin D in combination with different active ingredients of Chinese herbs under different therapeutic principles on proliferation and invasion of 4T1 and MDA-MB-231 breast cancer cell lines. METHODS: The effective doses of platycodin D, Ophiopogon total saponins, curcumenol and osthole in inhibiting proliferation of breast cancer cell lines 4T1 and MDA-MB-231 were detected by methyl thiazolyl tetrazolium (MTT) assay, respectively. Optimized combinations of platycodin D with Ophiopogon total saponins, curcumenol, or osthole were determined by uniform design method. Effects of the optimized combinations of platycodin D with the three ingredients on proliferation and invasion of 4T1 and MDA-MB-231 cells were verified and evaluated by MTT assay and Transwell chamber test, respectively. RESULTS: Verifying study showed that the inhibitory effects of platycodin D in combination with curcumenol or osthole on proliferation of 4T1 and MDA-MB-231 cells were better than those of platycodin D in combination with Ophiopogon total saponins and each ingredient used alone (P<0.05 or P<0.01). The inhibitory effect of platycodin D in combination with Ophiopogon total saponins or osthole on invasion of 4T1 cells was significantly better than those of platycodin D in combination with curcumenol and each ingredient used alone (P<0.05 or P<0.01). Moreover, the inhibitory effect of platycodin D in combination with curcumenol or osthole on invasion of MDA-MB-231 cells was significantly better than that of platycodin D in combination with Ophiopogon total saponins (P<0.01). CONCLUSION: The optimized combinations of platycodin D with three different active ingredients of Chinese herbs under different therapeutic principles can significantly inhibit the proliferation and decrease the invasion of 4T1 and MDA-MB-231 cells. Different platycodin D combinations have different potency in suppressing breast cancer cell proliferation and invasion.

[Inhibitory effects of osthole, psoralen and aconitine on invasive activities of breast cancer MDA-MB-231BO cell line and the mechanisms].

OBJECTIVE: To explore the inhibitory effects and to investigate the mechanisms of combined treatment of osthole, psoralen with aconitine on human breast cancer cell line MDA-MB-231BO. METHODS: The best inhibitory concentration of osthole, psoralen combined with aconitine on MDA-MB-231BO cells was obtained by stepwise regression analysis after adopting a uniform experiment design. The invasive activities were observed by transwell assays, and expressions of transforming growth factor-ß1 (TGF-ß1), Smad2, Smad3, Smad4, Smad7, nuclear factor-κB (NF-κB) and receptor activator of NF-κB ligand (RANK) mRNAs were analyzed by real-time quantitative polymerase chain reaction. RESULTS: The optimal combination concentrations of osthol, psoralen and aconitine were 6.44, 8.89 and 9.44 µg/mL, respectively. Cell invasion was significantly inhibited after 24 hours of treatment using the combination drugs and zoledronic acid. TGF-ß1, Smad2, Smad3, Smad4, Smad7, NF-κB and RANK mRNA expressions of the optimal combination group and zoledronic acid group were significantly reduced compared with the control group (P<0.01). Furthermore, TGF-ß1, Smad2, Smad3, Smad4, Smad7, NF-κB and RANK mRNA expressions of the optimal combination group were significantly lower than those of the weak combination group (P<0.01). CONCLUSION: Combination treatment of osthole, psoralen with aconitine can inhibit cancer cell invasion, which is a result of alteration of the TGF-ß/Smad signaling pathway and down-regulation of NF-κB and RANK expressions.

[Attenuation and mechanism of endoplasmic reticulum stress-mediated hepatocyte apoptosis in rats with alcohol-induced liver injury by qinggan huoxue recipe and its disassembled formulas].

OBJECTIVE: To explore attenuation and mechanism of endoplasmic reticulum stress (ERS)-mediated hepatocyte apoptosis in rats with alcohol-induced liver injury by Qinggan Huoxue Recipe (QGHXR) and its disassembled formulas (Qinggan Recipe and Huoxue Recipe respectively). METHODS: A rat model of chronic alcoholic liver injury was successfully established using a compound reagent of alcohol, corn oil, and pyrazol. The modeled rats were randomly divided into the model group, the QGHXR group, the Qinggan Recipe (QGR) group, and the Huoxue Recipe group (HXR). The CCl4 control group and the normal control group were also set up. There were ten rats in each group. All rats of modeled groups were gastrogavaged with alcohol compound reagent every morning. Rats in the QGHXR group (at the daily dose of 9. 5 g/kg, QGR group (at the daily dose of 3.0 g/kg), and HXR group (at the daily dose of 6.5 g/kg) were administered with corresponding medicines by gastrogavage every afternoon. Equal volume of normal saline was given to rats of the model group by gastrogavage. CCl4 was intraperitoneally injected at the dose of 0.3 mL/kg to rats in the CCl4 control group, once per week. Normal saline was given to rats in the normal control group by gastrogavage. The treatment was lasted for two weeks. Pathological changes of the liver were observed by histopathology. Serum total homocysteine (tHCY) level was detected by ELISA. The hepatocyte apoptosis rate was detected using flow cytometry. The gene and protein expressions of eukaryotic translation initiation factor 2 alpha (elF-2alpha), phosphorylation elF-2alpha (pelF-2alpha), glucose-regulated protein 78 (GRP78), and Caspase-3 in the liver were examined using Real-time PCR and Westen blot respectively. RESULTS: Compared with the normal control group, typical pathological changes of chronic alcoholic liver injury such as steatosis, inflammation, and even fibrosis occurred in model rats. The hepatocyte apoptosis obviously increased, with the apoptosis rate reaching the five-fold of that in normal rats. Besides, early apoptosis dominated. The serum tHCY level significantly increased. The expressions of p-elF-2alpha, GRP78, and Caspase-3 protein obviously increased (P < 0.01). Expressions of GRP78 and Caspase-3 mRNA significantly increased (P < 0.05, P < 0.01). Compared with the model group, the degrees of the liver injury and the hepatocyte apoptosis in the QGHXR group, the QGR group, and the HXR group were significantly alleviated. The serum tHCY level was significantly lowered. The protein expressions of p-elF-2a, GRP78, and Caspase-3 obviously decreased (P < 0.01). mRNA expressions of GRP78 and Caspase-3 obviously decreased in the QGHXR group (P < 0.05, P < 0.01). Only GRP78 mRNA expression obviously decreased in the QGR group (P < 0.05). CONCLUSION: QGHXR and its disassembled formulas could attenuate ERS-mediated hepatocyte apoptosis in alcohol-induced liver injury rats by lowering the serum tHCY level and expressions of ERS apoptosis correlated factors.

Influences of Fructus evodiae pretreatment on the pharmacokinetics of Rhizoma coptidis alkaloids.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhizoma coptidis is a traditional Chinese medicine with pharmacological properties. It is usually prescribed with Fructus evodiae as traditional Chinese medicine (TCM) formulas. Here we report the influences of Fructus evodiae on the pharmacokinetics of the Rhizoma coptidis alkaloids and propose possible mechanisms. MATERIALS AND METHODS: Pharmacokinetic experiments were performed in rats. In vitro absorption experiments were performed in everted rat gut sacs, while in vitro metabolism experiments and determination of hepatic UDP-glucuronosyltransferase (UGT) 1A1 mRNA expression were performed in rat liver microsomes. RESULTS: Pretreatment with Fructus evodiae extract for two weeks decreased the systemic exposure of the Rhizoma coptidis alkaloids. This effect was not due to inhibition of absorption or enhanced hepatic phase I metabolism of the Rhizoma coptidis alkaloids. However, Fructus evodiae pretreatment enhanced both the activity and expression of hepatic UGT1A1. CONCLUSIONS: The results showed that Fructus evodiae pretreatment decreased the systemic exposure of the Rhizoma coptidis alkaloids by inducing hepatic UGT1A1.

Astragaloside IV regulates expression of ATP-sensitive potassium channel subunits after ischemia-reperfusion in rat ventricular cardiomyocytes.

OBJECTIVE: Astragaloside IV (AsIV) is the major effective component extracted from the Chinese herb Astragalus membranaceus, which has been widely used to treat cardiovascular disease. Recent studies have shown that AsIV can potentially protect the heart from myocardial ischemic injury, but the mechanisms of action are unknown. ATP-sensitive potassium (KATP) channels are activated during ischemia and exert a compensatory protective effect on cardiomyocytes. We therefore examined the effects of AsIV on KATP channel currents and channel expression in isolated rat ventricular cardiomyocytes after ischemia-reperfusion injury. METHODS: Forty Wistar rats were divided into five groups: control group, ischemia-reperfusion (IP) group, IP + glibenclamide group, IP + pinacidil group and IP + AsIV group. The ischemia-reperfusion injury model was established in enzymatically isolated ventricular cardiomyocytes by perfusion with calcium-free Tyrode solution for 10 min, arrest for 30 min, and reperfusion for 45 min. The different drugs were applied for 10-15 min, and the KATP channel current (I(KATP)) was recorded with voltage-clamp mode by whole-cell patch-clamp technique. Protein and mRNA expression of the KATP channel subunits Kir6.1, Kir6.2, SUR2A and SUR2B was quantified using western blotting and real-time PCR. RESULTS: The KATP current in IP group was significantly greater than that in control group (211.45 +/- 33.67 vs 83.51 +/- 23.67 pA; P < 0.01). Glibenclamide (10 micromol/L) blocked KATP currents, whereas both AsIV (1 mg/L) and the known channel opener pinacidil (50 micromol/L) significantly increased I(KATP) (P < 0.05). Consistent with this, AsIV significantly up-regulated protein and mRNA expression of Kir6.1, Kir6.2, SUR2A, SUR2B (P < 0.01 vs IP group). CONCLUSION: The protective effects of AsIV in ischemia-reperfusion injury may be related to the up-regulation of several KATP channel subunits and facilitation of KATP currents.

[Role of PERK/eIF2a signaling pathway in hepatocyte apoptosis of alcoholic liver injury rats].

OBJECTIVE: To investigate the role of PERK/eIF2alpha signaling pathway in hepatocyte apoptosis of alcoholic liver injury rats. METHODS: Rat models with ethanol-induced liver injury were successfully developed by gastric gavage with ethanol-corn oil mixtures for 12 weeks. At different time points (4, 6, 10, 12 week), liver pathology was dynamically observed. The hepatocyte apoptosis was quantitatively analyzed by Annexin V-FITC/PI double-labeled flow cytometry, the serum total homocysteine (tHCY) level was detected by ELISA and the expressions of eIF2a, p-eIF2a, GRP78/Bip, GRP94, caspase-3 and caspase-12 in liver were examined using Real-time PCR and Western blot. RESULTS: Typical acute liver injury and chronic liver injury were observed at week 4 and week 12 respectively. The hepatocyte apoptosis rates in 6-week model rats significantly increased compared with normal rats (P value less than 0.05), and the degree of hepatocyte apoptosis continued to increase with the modeling time, and the percentages of early and total apoptosis reached 26% and 29% at week 12. From week 6 to week 12, the serum tHCY levels in model rats were obviously higher than in normal rats (P value less than 0.01). Since week 4, eIF2a protein phosphorylation in model rat livers remarkably elevated compared with that in normal rat livers (P value less than 0.01), and at week 12 the peIF2a protein expression in model rat livers increased by 2.81-fold. Since week 4 the expressions of GRP78/Bip, GRP94, caspase-12 and caspase-3 mRNA and protein in model rat livers showed a significant increase as compared to normal rat livers, and at week 12, these gene and protein levels increased 4.70, 12.95, 3.83, 4.05 fold and 3.93, 6.93, 9.88, 3.31 fold, respectively (P value less than 0.01). CONCLUSION: Activation of PERK/eIF2a signaling pathway contributes to the occurrence and development of hepatocyte apoptosis in alcoholic liver injury rats and it might be as a potential target for therapeutic applications in alcoholic liver diseases.

[Effects of serum containing Fructus Cnidii and Psoralea corylifolia on highly metastatic human breast cancer cell line MDA-MB-231BO and bone marrow stromal cell line ST-2].

OBJECTIVE: To explore the effects of different proportions of Fructus Cnidii (Shechuangzi) and Psoralea corylifolia (Buguzhi) on highly metastatic human breast cancer cell line MDA-MB-231BO and bone marrow stromal cell line ST-2 in vitro. METHODS: Thirty-six female SD rats were randomly divided into 6 groups to prepare the drug-medicated sera by administering with different proportions of Fructus Cnidii and Psoralea corylifolia, including 4:0 group, 3:1 group, 1:1 group, 1:3 group, 0:4 group and control group. MDA-MB-231BO cells and ST-2 cells were cultured in Dulbecco's modified Eagle's medium containing drug-medicated serum. Inhibition rates of MDA-MB-231BO cells and ST-2 cells were measured by methyl thiazolyl tetrazolium (MTT) method; migration ability of MDA-MB-231BO cells was tested by a cell migration experiment; alkaline phosphatase activity (ALP) of ST-2 cells was measured by using 4-nitrophenyl phosphate disodium salt, and mineralized nodule formation of ST-2 cells was measured by alizarin red staining. RESULTS: Sera contaning different proportions of Fructus Cnidii and Psoralea corylifolia inhibited the migration activity of MDA-MB-231BO cells as compared with the blank serum, and serum contaning Fructus Cnidii and Psoralea Corylifolia at proportion of 1:1 had the best function (P<0.01). Fructus Cnidii and Psoralea corylifolia at ratio of 1:1 also enhanced the ALP activity of ST2 cells (P<0.05) and increased the number of mineralized nodules of ST2 cells (P<0.01). CONCLUSION: Kidney-warming recipe of Fructus Cnidii and Psoralea corylifolia can inhibit proliferation and migration of MDA-MB-231BO cells and increase the activity of ST-2 cells.

[Effects of Guanxinkang on expressions of ATP-sensitive potassium channel subunits Kir6.1, Kir6.2, SUR2A and SUR2B in ischemic myocytes of rats].

OBJECTIVE: To observe the effects of Guanxinkang injection, a compound traditional Chinese herbal medicine, on ATP-sensitive potassium (K(ATP)) channel subunits in ischemic myocardial cells of rats, and to explore the mechanism of Guanxinkang in protecting myocardial ischemic reperfusion injuries. METHODS: Forty-eight Wistar rats were randomly divided into normal group, untreated group, glibenclamide group, pinacidil group, Guanxinkang group and Guanxinkang plus glibenclamide group. The ventricular myocytes were prepared from hearts of normal rats by enzymatic dissociation method. The ischemic ventricular myocytes underwent perfusion with normal Tyrode solution for 10 min, then stopping perfusion 30 min, and followed by 45 min of reperfusion. The glibenclamide, pinacidil and Guanxinkang were added into ventricular myocytes solution directly. Then the solutions were placed at 4 degrees centigrade. After 24-hour freezing at -80 degrees centigrade, mRNA and protein expressions of KATP subunits Kir6.1, Kir6.2, SUR2A and SUR2B were measured by real-time quantitative polymerase chain reaction and Western blotting respectively. RESULTS: In normal rat myocardial cells, there were SUR2A, Kir6.1, and Kir6.2 protein and gene expressions but no expression of SUR2B protein. In the untreated group, all subunit mRNA and protein expressions of KATP increased to some extent as compared with the normal group. Pinacidil, a potassium channel opener, significantly increased mRNA and protein expressions of KATP subunits, while the blocker glibenclamide had a reverse effect. Meanwhile, Guanxinkang injection significantly increased mRNA and protein expressions of K(ATP) subunits but with no significant difference as compared with pinacidil. CONCLUSION: Guanxinkang injection can obviously enhance the open of KATP channel and thus play a role in cardiovascular protection.