Deubiquitylase USP31 Induces Autophagy and Promotes the Progression in Lung Squamous Cell Carcinoma Cells by Stabilizing E2F1 Expression.

BACKGROUND: Autophagy exerts a vital role in the progression of lung squamous cell carcinoma (LUSC). Ubiquitin-specific peptidase 31 (USP31) has recently been found to be involved in the development of a variety of cancers. However, whether USP31 modulates autophagy in LUSC remains unclear. METHODS: This study revealed that high levels of USP31 were discovered in LUSC tissue samples employing the Gene Expression Profiling Interactive Analysis (GEPIA) database, quantitative real- time PCR (qRT-PCR), and Western blot analysis. Cell proliferation was tested via cell counting kit 8 (CCK-8) as well as colony formation, demonstrating that USP31-stable knockdown reduced cell viability. RESULTS: Immunofluorescence analysis illustrated that USP31 knockdown blocked the occurrence of LUSC autophagy. Meanwhile, USP31 has been shown to stabilize the expression of E2F transcription factor 1 (E2F1) through the proteasome pathway. Furthermore, overexpressed E2F1 effectively eliminated the effect of USP31 knockdown on LUSC cell proliferation and autophagy. CONCLUSION: In summary, this investigation proved that USP31 promoted LUSC cell growth and autophagy, at least in part by stabilizing E2F1 expression, which provided a potential therapeutic gene for the treatment of LUSC.

Improvement the Flame Retardancy and Thermal Conductivity of Epoxy Composites via Melamine Polyphosphate-Modified Carbon Nanotubes.

Surface chemical modification of carbon nanotubes can enhance the compatibility with polymers and improve flame retardancy performances. In this work, the double bond active sites were constructed on the surface of carbon nanotubes modified by the γ-methacryloyloxypropyl trimethoxysilane (KH570). Glycidyl methacrylate (GMA) was further grafted onto the surface of carbon nanotubes via free radical polymerization. Finally, the flame retardant melamine polyphosphate (MPP) was bonded to the surface of carbon nanotubes by the ring-opening reaction. This modification process was proved to be achieved by infrared spectroscopy and thermogravimetric test. The carbon nanotubes modified by flame retardant were added into the epoxy matrix and cured to prepare flame retardant and thermal conductive composites. The flame retardancy of composites were studied by cone calorimetry, UL94 vertical combustion test and limiting oxygen index. The thermal conductivity of composites was characterized by laser thermal conductivity instrument. The results showed that when the addition amount of flame retardant MPP-modified carbon nanotubes in composites was 10 wt%, the flame retardant level of UL94 reached to V2, the limiting oxygen index increased from 25.1 of pure epoxy resin to 28.3, the PHRR of pure epoxy resin was reduced from 800 kW/m2 to 645 kW/m2 of composites and thermal conductivity of composites was enhanced from 0.21 W/m·K-1 of pure epoxy resin to 0.42 W/m·K-1 of the composites.

Sound Insulation Properties of Hollow Polystyrene Spheres/Polyethylene Glycol/Epoxy Composites.

The generation of noise requires a noise source, transmission path, and passive acceptance target of noise, all of which are indispensable. Blocking the propagation path of noise is one of the available means when the existence of the noise source and passive receiving target cannot be addressed. This is an effective way to prevent noise pollution, often using sound insulation materials to block the path of noise transmission. In this work, composites with excellent sound insulation properties were designed and prepared. These composites, using epoxy resin (EP) as the matrix, polyethylene glycol (PEG), and hollow polystyrene spheres (HPS), were added to epoxy resin as a toughening agent and functional filler to prepare the ternary HPS/PEG/EP composites. The soundproofing results showed that when the thickness of the sample was 3 mm, the average sound transmission loss (STL) value of the neat EP and the HPS/PEG/EP composites with an HPS 32 vol% was up to 19.0 dB and 42.1 dB, and the STL values of the composites were increased by approximately 120% compared to the pure epoxy. When the sample was 10 mm thick, the average STL value of the HPS/PEG/EP composites with HPS 32 vol% contents was enhanced to 55.7 dB.

Tin-sulfur based catalysts for acetylene hydrochlorination.

In the present work, tin-sulfur based catalysts were prepared using Na2SO3 and (CH3SO3)2Sn and were tested in acetylene hydrochlorination. Based on the analysis of experiments results, the acetylene conversion of (CH3SO3)2Sn/S@AC is still over 90%after a 50 h reaction, at the reaction conditions of T = 200 oC, VHCl/VC2H2 = 1.1:1.0 and C2H2-GSHV = 15 h-1. According to the results of X-ray photoelectron spectroscopy (XPS), HCl adsorption experiments, and acetylene temperature programmed desorption (C2H2-TPD), it is reasonable to conclude that the interaction between Sn and S not only can retard the oxidation of Sn2+ in catalysts but also strengthen the reactant adsorption capacity of tin-based catalysts. Furthermore, results obtained from nitrogen adsorption/desorption and XPS proved that the CH3SO3- can effectively decrease the coke deposition of (CH3SO3)2Sn/AC and thus prolong the lifetime of (CH3SO3)2Sn/AC.

Neoadjuvant immunotherapy for resectable non-small cell lung cancer.

Lung cancer is the malignant tumor with the highest morbidity and mortality in the world. In recent ten years, with the emergence of new drugs and the optimization of treatment mode, the treatment of lung cancer is entering an era of precision and individualization. Neoadjuvant therapy can reduce tumor size, degrade tumor stage, kill circulating tumor cells and micrometastases in the body, afford operation possibility, and benefit the long-term survival of patients. However, the traditional neoadjuvant chemotherapy combined with surgical treatment seems to have entered the bottleneck period of efficacy and is difficult to achieve breakthrough progress. At the same time, the amazing efficacy of immunotherapy is gradually innovating the treatment mode of lung cancer. In recent years, the research data of immune checkpoint inhibitors in the treatment of non-small cell lung cancer (NSCLC) shows an explosive growth. Immunotherapy has been applied to the first-line treatment of advanced NSCLC. Therefore, some clinical trials have applied immunotherapy to neoadjuvant treatment of resectable NSCLC patients. In this paper, the efficacy, possible mechanisms, potential risks and existing problems of neoadjuvant immunotherapy for resectable NSCLC patients are reviewed, and the future development direction of neoadjuvant immunotherapy is discussed.

Effect of Homebuyer Comment on Green Housing Purchase Intention-Mediation Role of Psychological Distance.

Green housing is a new type of building that advocates energy saving and environmental protection. How to stimulate buyers to buy green housing under the background of high cost is the key problem to guide green consumption. First of all, based on the existing literature, the comment of homebuyers was divided into comment quantity, comment quality, comment titer and evaluator credibility. The psychological distance mediation variable was introduced, and three dimensions of time distance, social distance, and space distance were selected to construct the influence model of homebuyer comment on green housing purchase intention. Meanwhile, the concept model was built, and questionnaires were adopted for empirical analysis. On this basis, considering the long-term purchase behavior of buyers, the influence model of homebuyers' second comment on green housing purchase intention with the Hotelling model was established. The results show that comment quality, comment titer, and the credit rating of the evaluator have a positive effect on green housing purchase intention while comment quantity has no significant effect. Psychological distance plays a mediation role between comment quality, comment titer, the credit rating of the evaluator, and green housing purchase intention while having a mediation effect between comment quantity and green housing purchase intention. In the long-term purchase behavior of green housing, psychological distance plays a greater role than price. At last, some suggestions were proposed.

Overexpression of LiTPS2 from a cultivar of lily (Lilium 'Siberia') enhances the monoterpenoids content in tobacco flowers.

Lily, a famous cut flower with highly fragrance, has high ornamental and economic values. Monoterpenes are the main components contributing to its fragrance, and terpene synthase (TPS) genes play critical roles in the biosynthesis of monoterpenoids. To understand the function of TPS and to explore the molecular mechanism of floral scent in cultivar Lilium 'Siberia', transcriptomes of petal at different flowering stages and leaf were obtained by RNA sequencing and three unigenes related to TPS genes were selected for further validation. Quantitative real-time PCR showed that the expression level of LiTPS2 was greater than that of the other two TPS genes. Phylogenetic analysis indicated that LiTPS2 belonged to the TPSb subfamily, which was responsible for monoterpenes synthesis. Subcellular localization demonstrated that LiTPS2 was located in the chloroplasts. Furthermore, functional characterization showed that LiTPS2 utilized both geranyl pyrophosphate (GPP) and farnesyl pyrophosphate (FPP) to produce monoterpenoids such as linalool and sesquiterpenes like trans-nerolidol, respectively. Ectopic expression in transgenic tobacco plants suggested that the amount of linalool from the flowers of transgenic plants was 2-3 fold higher than that of wild-type plants. And the emissions of myrcene and (E)-ß-ocimene were also accumulated from the flowers of LiTPS2 transgenic lines. Surprisingly, these three compounds were the main fragrance components of oriental lily hybrids. Our results indicated that LiTPS2 contributed to the production of monoterpenes and could effectively regulate the aroma of Lilium cultivars, laying the foundation for biotechnological modification of floral scent profiles.

MARCKSL1 promotes the proliferation, migration and invasion of lung adenocarcinoma cells.

Lung cancer is the most common cancer in males and females and ~40% of lung cancer cases are adenocarcinomas. Previous studies have demonstrated that myristoylated alanine rich protein kinase C substrate (MARCKS) is upregulated in several types of cancer and is associated with poor prognosis in patients with breast cancer. However, its expression level and role in lung adenocarcinoma remain unknown. Therefore, the aim of the present study was to investigate the expression level and biological functions of MARCKS like 1 (MARCKSL1), a member of the MARCKS family, in lung adenocarcinoma. The expression level of MARCKSL1 was examined in human lung adenocarcinoma tissues and cell lines. MARCKSL1-specific small interfering RNAs effectively suppressed its expression level and significantly inhibited the proliferation, migration and invasion of lung adenocarcinoma cells. Additionally, the role of MARCKSLI in the regulation of metastasis was examined. Silencing MARCKSL1 decreased the expression of the epithelial-mesenchymal transition (EMT)-associated proteins E-cadherin, N-cadherin, vimentin and snail family transcriptional repressor 2, and decreased the phosphorylation level of AKT. The results obtained in the current study suggested that MARCKSL1 promoted the progression of lung adenocarcinoma by regulating EMT. MARCKSLI may have prognostic value and serve as a novel therapeutic target in lung adenocarcinoma.

miR-205-5p downregulation decreases gemcitabine sensitivity of breast cancer cells via ERp29 upregulation.

Breast cancer is the most common cancer in women worldwide, and the incidence and mortality rates are increasing every year. Dysregulation of microRNAs (miRNAs or miRs) is an important step in the initiation and development of breast cancer. Previous studies demonstrated that miR-205-5p is closely associated with occurrence and development of breast cancer; however, underlying mechanisms remain unclear. In the present study, reverse transcription-quantitative polymerase chain reaction assays were used to analyze miR-195-5p and endoplasmic reticulum protein 29 (ERp29) levels in breast cancer and matched normal tissues. Western blot analysis was performed to analyze ERp29 and heat shock protein 27 (HSP27) protein expression levels. Cell viability, flow cytometry and luciferase reporter assay were used to examine cell proliferation, apoptosis and direct miRNA-mRNA binding, respectively. The results revealed that miR-205-5p expression in breast cancer tissues and cell lines was decreased compared with normal tissues and a normal cell line. Overexpression of miR-205-5p significantly augmented cytotoxicity effects of gemcitabine treatment in MDA-MB-231 and BT549 cells. It was observed that miR-205-5p negatively regulated ERp29 expression in breast cancer cells. Dual luciferase assays confirmed that ERp29 was a target of miR-205-5p in breast cancer cells. Additionally, following the established gemcitabine-resistant MDA-MB-231 cells (MDA-MB-231/GEM), ERp29 and HSP27 expression was upregulated and miR-205-5p was downregulated compared with parental cells. Overexpression of miR-205-5p reversed gemcitabine resistance in MDA-MB-231/GEM cells. In conclusion, the present study indicated that miR-205-5p may inhibit gemcitabine resistance in breast cancer cells via inhibition of ERp29 expression.

miR-107 Enhances the Sensitivity of Breast Cancer Cells to Paclitaxel.

Breast cancer remains the most commonly diagnosed cancer in Chinese women. Paclitaxel (PTX) is a chemotherapy medication used to treat breast cancer patients. However, a side effect of paclitaxel is the severe drug resistance. Previous studies demonstrated that dysregulation of microRNAs could regulate sensitivity to paclitaxel in breast cancer. Here, the present study aimed to lucubrate the underlying mechanisms of miR-107 in regulating the sensitivity of breast cancer cells to PTX. The results demonstrated that miR-107 was down-regulated in breast cancer tumor tissues, while TPD52 was significantly up-regulated compared with the non-tumor adjacent tissues. After confirming that TPD52 may be a major target of miR-107 via a dual-luciferase reporter assay, the western blot and RT-qPCR assays further demonstrated that miR-107 may reduce the expression level of TPD52 as well. In addition, miR-107 may prominently enhance PTX induced reduction of cell viability and the promotion of cell apoptosis in breast cancer, and the variation could be reversed by co-transfected with pcDNA3.1-TPD52. Finally, miR-107 could further reduce the decreased expression of TPD52, Wnt1, ß-catenin and cyclin D1 that was induced by PTX in both mRNA and protein levels, which were rescued by pcDNA3.1-TPD52 indicating that miR-107 regulated breast cancer cell sensitivity to PTX may be targeting TPD52 through Wnt/ß-catenin signaling pathway.

Overexpression of LiDXS and LiDXR From Lily (Lilium 'Siberia') Enhances the Terpenoid Content in Tobacco Flowers.

Lilium, the famous and significant cut flower, emits a variety of volatile organic compounds, which mainly contain monoterpenes, such as myrcene, (E)-ß-ocimene, and linalool. To understand the molecular mechanism of monoterpene synthesis in Lilium, we cloned two potential genes in the methylerythritol 4-phosphate pathway, namely LiDXS and LiDXR, from the strong-flavored oriental Lilium 'Siberia' using a homology-based PCR strategy. The expression levels of LiDXS and LiDXR were consistent with the emission and accumulation of monoterpenes in different floral organs and during the floral development, indicating that these two genes may play key roles in monoterpene synthesis. Subcellular localization demonstrated that LiDXS and LiDXR are expressed in the chloroplasts. Ectopic expression in transgenic tobacco suggested that the flowers of LiDXS and LiDXR transgenic lines accumulated substantially more diterpene, sclareol, compared to the plants transformed with empty vector. Surprisingly, increased content of the monoterpene, linalool and sesquiterpene, caryophyllene, were detected in the LiDXR transgenic lines, whereas the emission of caryophyllene, increased in one of the LiDXS transgenic tobacco lines, indicating that these two genes play significant roles in the synthesis of floral volatiles in the transgenic plants. These results demonstrate that LiDXR can contribute to monoterpene biosynthesis in Lilium 'Siberia'; however, the role of LiDXS in the biosynthesis of monoterpenes needs further study.

Emodin Exerts an Antiapoptotic Effect on Human Chronic Myelocytic Leukemia K562 Cell Lines by Targeting the PTEN/PI3K-AKT Signaling Pathway and Deleting BCR-ABL.

The BCR-ABL kinase inhibitor, imatinib mesylate, is the front-line treatment for chronic myeloid leukemia, but the emergence of imatinib resistance has led to the search for alternative drug treatments. There is a pressing need, therefore, to develop and test novel drugs. Natural products including plants, microorganisms, and halobios provide rich resources for discovery of anticancer drugs. In this article, we demonstrate that emodin inhibited the growth of K562 cells harboring BCR-ABL in vitro and in vivo, and induced abundant apoptosis, which was correlated with the inhibition of PETN/PI3K/Akt level and deletion of BCR-ABL. These findings suggest that emodin is a promising agent to kill K562 cells harboring BCR-ABL.

MiR-34a suppresses ovarian cancer proliferation and motility by targeting AXL.

Increasing evidence has suggested that dysregulation of microRNAs (miRNAs) could contribute to tumor progression. The miR-34 family is directly transactivated by tumor suppressor p53 which is frequently mutated in various cancers; however, the effect of miR-34a on the ovarian cancer cells remains unclear. The aim of the paper was to study the expression of miR-34a in ovarian cancer and miR-34a's relation to the cell proliferation and metastasis in ovarian cancer in vitro. miR-34a expression was determined by quantitative RT-PCR in a panel of 60 human ovarian cancer samples. Functional characterization of miR-34a was accomplished by reconstitution of miR-34a expression in ovarian cancer cells by determining changes in proliferation, migration, and invasion. Our results showed that miR-34a is downregulated in ovarian cancer tissues compared with the corresponding adjacent non-neoplastic tissues, and the expression level of miR-34a was significantly lower in ovarian cancer cell lines in comparison with normal human fallopian tube epithelial cell line. The 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide (MTT) assay revealed significant cell proliferation inhibition in miR-34a transfectant compared with the control from HO8910 and SKOV3 cells, which displayed lowest expressions of miR-34a. Furthermore, the transwell assay also showed significant cell migration inhibition in miR-34a transfectant, compared with cell lines transfected with NC. Overexpression of miR-34a led to the inhibition of AXL expression, indicating that AXL is a target gene for miR-34a. Our data suggest that miR-34a may function as a tumor suppressor through repression of oncogenic AXL in ovarian cancer.

Downregulation of cell cycle-related proteins in ovarian cancer line and cell cycle arrest induced by microRNA.

OBJECTIVE: The effect of miR-449 and miR-34 on the growth, cell cycle and target gene expressions of ovarian cancer cell line SKOV3 and SKOV3-ipl was discussed. METHOD: Real-time quantitative reverse transcription PCR was employed to detect the expressions of miR-449a/b and miR-34b, c in SKOV3 and SKOV3-ipl cells. The two miRNAs were successfully expressed in SKOV3-ipl cells by transfection. The variations in cell growth rate and cell cycle were determined by MTS assay and flow cytometry, respectively. The expressions of cell cycle-related proteins were detected by Western Blot. RESULTS: miR-449b and miR-34c induced the decline of the adhesiveness of SKOV3-ipl cells by 20%-30%. The number of cells arrested in G1-phase increased and the number of cells arrested in S-phase decreased significantly. The cell cycle-related proteins CDK6 and CDC254 were downregulated. miR-449b caused the expression of CDK6 and CDC25A to decrease. After the co-transfection with miR-449b and miR-34c, the relevant proteins were downregulated more significantly. The expressions of CDK6, CDC25A and cyclin A were decreased significantly. CONCLUSION: miR-449b and miR-34c can induce cell cycle arrest in SKOV3-ipl cells and the downregulation of CDK6, CDC25A and cyclin A.

Serum cyfra21-1 as a biomarker in patients with nonsmall cell lung cancer.

OBJECTIVE: The purpose of this retrospective study was to evaluate the clinical value of serum cytokeratin-19-fragment (cyfra21-1) as a biomarker in nonsmall cell lung cancer (NSCLC). METHODS: Sixty-six patients with NSCLC and 48 cases with benign lung disease were retrospectively analyzed in the department of thoracic surgery in our hospital. The serum level of cyfra21-1 was detected in the above patients. The diagnosis sensitivity, specificity and the receiver operating characteristic curve were calculated by using the stata11.0 statistical software to evaluate the clinical diagnosis value of serum Cyfra21-1 as NSCLC serologic biomarker. RESULTS: The mean of serum cyfra21-1 were 8.95 eat. 01 µ/L and 4.28 eat. 89 µ/L in NSCLC patient and control groups respectively, which indicated that the NSCLC group were much higher (P < 0.05). The diagnosis sensitivity and specificity were 77.08% and 63.64% at the threshold of 6.32 µ/L respectively. Moreover, the area under the curve was 0.78 (95% confidence interval: 0.70-0.87). CONCLUSION: Serum cyfra21-1 can be a potential serologic biomarker in evaluation of NSCLC.

Size effects in atomic-level epitaxial redistribution process of RuO2 over TiO2.

Controls over the atomic dispersity and particle shape of noble metal catalysts are the major qualities determining their usability in industrial runs, but they are usually difficult to be simultaneously realized. Inspired from the Deacon catalyst in which RuO(2) can form epitaxial layers on the surfaces of Rutile TiO(2), here we have investigated the shape evolution process of RuO(2) nanoparticles on the surface of P25 TiO(2). It is found that size effects exist in this process and RuO(2) nanoparticles with sizes ~sub-2 nm can be transformed into epitaxial layers while nanoparticles with bigger sizes are not apt to change their shapes. Based on a thermodynamic model, we infer such transformation process is jointly driven by the surface tension and interfacial lattice match between the nanoparticles and substrates, which may be suggestive for the design of noble metal catalysts integrating both active crystal planes and high atomic exposure ratios.

MicroRNA-191 targets N-deacetylase/N-sulfotransferase 1 and promotes cell growth in human gastric carcinoma cell line MGC803.

As a family of post-transcriptional regulator of gene expression, the microRNAs (miRNAs) control a wide array of biological processes including cell differentiation, proliferation and apoptosis, and the dysregulation of miRNAs is a hallmark of cancer. Here, we found that the microRNA-191 (miR-191) was at a high-expression level in human gastric adenocarcinoma cell line MGC803 and human gastric cancer tissues. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony formation assays showed that miR-191 could promote cell growth and suppress apoptosis of MGC803 cells. The N-deacetylase/N-sulfotransferase 1 (NDST1) was confirmed to be a direct target gene of miR-191 by enhanced green fluorescent protein reporter experiment. The mRNA and protein levels of NDST1 were inversely correlated with miR-191 in MGC803 cells, suggesting the negative regulation of NDST1 by miR-191. Furthermore, NDST1 played an inhibitory role and could suppress MGC803 cell proliferation. Our findings suggested that miR-191 could act as an oncogene in MGC803 cells, and the cellular function was partially due to its negative regulation of NDST1.

Catalytic conversion of xylose to furfural over the solid acid SO4 ²â»-/ZrO2-Al2O3/SBA-15 catalysts.

Al-promoted SO4 ²â»-/ZrO2SBA-15 catalysts were prepared and characterized by XRD, BET, ICP and NH3-TPD techniques. The influence of introducing aluminum on the structure and surface properties of the catalyst and the catalytic activity for dehydration of xylose to furfural has been investigated. The introduction of the Al stabilizes the tetragonal phase of the ZrO2 and thus increases the number and intensity of acid sites. Based on the characterization of the deactivated catalyst, the accumulation of byproducts is the main reason for the deactivation of the catalyst. Regeneration with H2O2 can completely recover the catalytic activity of the deactivated catalyst.

[Effects of different types of litters on soil organic carbon mineralization].

Using litter incubation experiment in laboratory, decomposition discrepancies of four typical litters from Zijin Mountain were analyzed. The results show that organic carbon mineralization rates of soil with litters all involve fast and slow decomposition stages, and the differences are that the former has shorter duration,more daily decomposition quantity while the latter is opposite. Organic carbon mineralization rates of soil with litters rapidly reached maximum in the early days of incubation, and the order is soil with Cynodon dactylon litter (CK + BMD) (23.88 +/- 0.62) mg x d(-1), soil with Pinus massoniana litter (CK+ PML) (17.93 +/- 0.99) mg x d(-1), soil with Quercus acutissima litter (CK+ QAC) (15.39 +/- 0.16) mg x d(-1) and soil with Cyclobalanopsis glauca litter (CK + CGO) (7.26 +/- 0.34) mg x d(-1), and with significant difference between each other (p < 0.05). This order has not significant correlation to litter initial chemical elements. The amount of organic carbon mineralized accumulation within three months incubation is (CK + BMD) (338.21 +/- 6.99) mg, (CK + QAC) (323.48 +/- 13.68) mg, (CK + PML) (278.34 +/- 13.91) mg and (CK + CGO) (245.21 +/- 4.58) mg. 198.17-297.18 mg CO2-C are released during litter incubation, which occupies 20.29%-31.70% of the total litter organic carbon amounts. Power curve model can describe the trends of organic carbon mineralization rate and mineralized accumulation amount,which has a good correlation with their change.

[Study on effect of Tiaomaiyin injection on experimental arrhythmia].

OBJECTIVE: To study the effect of Tiaomaiyin injection on the experimental arrhythmia for analyzing its underlying mechanism in the treatment of cardiovascular disease. METHOD: Experimental animals anesthetized with 20% urethane (6 mL x kg(-1)) were evenly randomized into control group, positive control group, low-dose and high-dose Tiaomaiyin group. The rate of ventricular fibrillation (VF) chloroform-induced in mice, and the epoch of ventricular extrasystole (VE), ventricular tachycardia (VT),VF and cardiac arrest (CA), actonitine-induced in rats (1.0 microg x mL(-1) x min(-1)), and vabain-induced in guinea pigs (10 microg x mL(-1) x min(-1)), were detected respectively. The result loas converted into cumulative dosage of actonitine or vabain. In ischemia-reperfusion model in rats, the duration of arrhythmia and activity of superoxide dismutase (SOD) and malondialdehyde (MDA) were detected. RESULT: After venous injection of Tiaomaiyin, VF in mice was lower significantly (P < 0.01), VE, VT, VF in rats and VF in guinea pigs were lowered considerably (P <0.05). The duration of arrhythmia in ischemia-reperfusion model was reduced considerably (P < 0.05), and the activity of myocardial SOD was raised significantly (P <0.01). CONCLUSION: Tiaomaiyin shows the reduction of experimental arrhythmia and protect effect to ischemia-reperfusion injury of the heart, which indicates that the effect mechanism may have the relationship with inhabition of lipid peroxidation and damnification of the free radical.