Effect of baicalin on eradicating biofilms of bovine milk derived Acinetobacter lwoffii.

BACKGROUND: Acinetobacter lwoffii (A.lwoffii) is a serious zoonotic pathogen that has been identified as a cause of infections such as meningitis, bacteremia and pneumonia. In recent years, the infection rate and detection rate of A.lwoffii is increasing, especially in the breeding industry. Due to the presence of biofilms, it is difficult to eradicate and has become a potential super drug-resistant bacteria. Therefore, eradication of preformed biofilm is an alternative therapeutic action to control A.lwoffii infection. The present study aimed to clarify that baicalin could eradicate A.lwoffii biofilm in dairy cows, and to explore the mechanism of baicalin eradicating A.lwoffii. RESULTS: The results showed that compared to the control group, the 4 MIC of baicalin significantly eradicated the preformed biofilm, and the effect was stable at this concentration, the number of viable bacteria in the biofilm was decreased by 0.67 Log10CFU/mL. The total fluorescence intensity of biofilm bacteria decreased significantly, with a reduction rate of 67.0%. There were 833 differentially expressed genes (367 up-regulated and 466 down-regulated), whose functions mainly focused on oxidative phosphorylation, biofilm regulation system and trehalose synthesis. Molecular docking analysis predicted 11 groups of target proteins that were well combined with baicalin, and the content of trehalose decreased significantly after the biofilm of A.lwoffii was treated with baicalin. CONCLUSIONS: The present study evaluated the antibiofilm potential of baicalin against A.lwoffii. Baicalin revealed strong antibiofilm potential against A.lwoffii. Baicalin induced biofilm eradication may be related to oxidative phosphorylation and TCSs. Moreover, the decrease of trehalose content may be related to biofilm eradication.

Cytotoxic glutarimide-containing polyketides isolated from Streptomyces sp. JCM 4793.

Glutarimide-containing polyketides usually exhibit anti-fungi activity, which was well exampled by cycloheximide. In our work, three new polyketide structures, 12-amidestreptimidone (1), 12-carboxylstreptimidone (2) and 3-(5S,8R)-(2-amino-2-oxoethyl-2'-methoxy-2'-oxoethyl)-8,10-dimethyl-7-oxododeca-5-hydroxy-9E,11-diolefin (3) were isolated from Streptomyces sp. JCM 4793. 3 without the glutarimide moiety is not active against fungi as expected, while 1 bearing the amide moiety is much more active than its carboxylic form 2. Here we report the isolation, structural elucidation, antifungal activity, and proposed biosynthesis pathway of 1-3.

Five new limonoids isolated from Walsura robusta.

Five new toosendanin limonoids with highly oxidative furan ring walsurobustones A-D (1-4), and one new furan ring degraded limonoid walsurobustone E (5) together with one known compound toonapubesic acid B (6) were isolated from the leaves of Walsura robusta. Their structures were elucidated by NMR and MS data. Especially, the absolute configuration of toonapubesic acid B (6) was confirmed by X-ray diffraction study. Compounds 1-6 exhibited good cytotoxicity against the cancer cell lines HL-60, SMMC-7721, A-549, MCF-7, and SW480.

Effects of estradiol on depressive-like behavior of ovariectomized rats and its possible mechanism / 解剖学报

Objective To examine the effect of estradiol (E2) treatment on ovariectomy (OVX) induced depressive-like behavior and possible mechanism by measuring inflammatory biomarkers levels oi interleukin-6 (IL-6) and tumor necrosis tactor-(x (TNF-ot) and brain-derived neurotrophic factor (BDNF) expression in amygdaia nucleus. Methods Thirty nine healthy aduit 缶male SD rats were randomly divided into three groups : sham operation group (SO), ovariectomized group (OVX) and ovariectomized estradiol treatment group (OVX + E2). After 6 weeks of E2 treatment, depressive like behavior was evaluated by opening field test (OFT) and sugar water preference test (SPT). The levels of inflammatory factors IL-6 and TNF-a in amygdala were measured by ELESA, and the expression of BDNF in rat amygdala was detected by immunohistochemical staining. Results The result of the SPT showed that OVX significantly decreased the sugar intake and sugar preference rate of rats, and E2 treatment significantly increased sugar water intake and sugar water preference rate of rats. The result of the OFT showed that OVX significantly decreased the numbers of crossing and rearing of rats, and reduced the time spent in the centre ; E2 treatment significantly increased the numbers of crossing and rearing of rats, and prolonged the time spent in the centre. ELESA and immunohistochemical analysis found the levels of IL-6 and TNF-a in amygdala increased significantly, while the average absorbance (AA) of BDNF in the amygdala reduced significantly (P<0.01 respectively) of rats in OVX group when compared with the SO group. And the levels of IL-6 and TNF-a in amygdala decreased significantly (P<0.01 respectively), while the A4 of BDNF increased significantly (P< 0.05) in the amygdala of rats in the OVX+EX group when compared with the OVX group. The difference was statistically significant. Conclusion E2 treatment improved depression-like behavior of OVX rats is partly due to increased antiinflammatory and activated the BDNF expression in amygdaloid nucleus, thus enhancing the neuroprotective effect of OVX rats.

Effects of treadmill exercise on learning and memory of the vascular dementia rats and its mechanism / 解剖学报

Objective To observe the effects of 4-week low intensity treadmill exercise on the learning and memory, amino acid levels and the protein expression of protein kinase A ( PKA) , cyclic adenosine monophosphate response element binding protein( CREB) and brain-derived neurotrophic factor(BDNF) in the prefrontal cortex (PFC) of the vascular dementia (VD) rats. Methods Thirty-nine SD rats were randomly allocated to 3 groups, sham group (sham, n= 13) , vascular dementia group (VD, n= 13) and vascular dementia treaded with exercise group (VD + EX, n= 13). Chronic cerebral ischemia model in VD group and VD+EX group rats were established by permanent ligation of bilateral, then VD+EX group rats were submitted to 4-week low intensity treadmill exercise. After exercise, spatial learning and memory ability were evaluated by Moms water maze test ( MWM ) , glutamic ( Glu ) and gamma-aminobutyric acid (GABA) levels in the PFC were measured by high performance liquid chromatography( HPLC) ; the protein expression of PKA, CREB and BDNF in the PFC of rats were detected by Western blotting. Results The result of the MWM showed the average escape latency of rats in the VD group on the 1 -5 days was significantly higer than sham group, the time to first find the original platform was significantly prolonged and the platform crossings decreased significantly ( P 0. 05 ) between the two groups. Conclusion Four-week low-intensity running exercise improves the learning and memory ability of VD rats through enhancing the Glu level and activating PKA-CREB-BDNF signaling in the PFC of rats.

The mechanism of S100A7 inducing the migration and invasion in cervical cancer cells / 中华肿瘤杂志

Objective: To investigate the mechanism of S100A7 inducing the migration and invasion in cervical cancers. Methods: Tissue samples of 5 cases of cervical squamous cell carcinoma and 3 cases of adenocarcinoma were collected from May 2007 to December 2007 in the Department of Gynecology of the Affiliated Hospital of Qingdao University. Immunohistochemistry was performed to evaluate the expression of S100A7 in cervical carcinoma tissues. S100A7-overexpressing HeLa and C33A cells were established with lentiviral systems as the experimental group. Immunofluorescence assay was performed to observe the cell morphology. Transwell assay was taken to detect the effect of S100A7-overexpression on the migration and invasion of cervical cancer cells. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) was used to examine the mRNA expressions of E-cadherin, N-cadherin, vimentin and fibronectin. The expression of extracellular S100A7 in conditioned medium of cervical cancer cell was detected by western blot. Conditioned medium was added into Transwell lower compartment to detect cell motility. Exosomes were isolated and extracted from the culture supernatant of cervical cancer cell, the expressions of S100A7, CD81 and TSG101 were detected by western blot. Transwell assay was taken to detect the effect of exosomes on the migration and invasion of cervical cancer cells. Results: S100A7 expression was positively expressed in cervical squamous carcinoma and negative expression in adenocarcinoma. Stable S100A7-overexpressing HeLa and C33A cells were successfully constructed. C33A cells in the experimental group were spindle shaped while those in the control group tended to be polygonal epithelioid cells. The number of S100A7-overexpressed HeLa cells passing through the Transwell membrane assay was increased significantly in migration and invasion assay (152.00±39.22 vs 105.13±15.75, P<0.05; 115.38±34.57 vs 79.50±13.68, P<0.05). RT-qPCR indicated that the mRNA expressions of E-cadherin in S100A7-overexpressed HeLa and C33A cells decreased (P<0.05) while the mRNA expressions of N-cadherin and fibronectin in HeLa cells and fibronectin in C33A cells increased (P<0.05). Western blot showed that extracellular S100A7 was detected in culture supernatant of cervical cancer cells. HeLa cells of the experimental group passing through transwell membrane in migration and invasion assays were increased significantly (192.60±24.41 vs 98.80±47.24, P<0.05; 105.40±27.38 vs 84.50±13.51, P<0.05) when the conditional medium was added into the lower compartment of Transwell. Exosomes from C33A cell culture supernatant were extracted successfully, and S100A7 expression was positive. The number of transmembrane C33A cells incubated with exosomes extracted from cells of the experimental group was increased significantly (251.00±49.82 vs 143.00±30.85, P<0.05; 524.60±52.74 vs 389.00±63.23, P<0.05). Conclusion: S100A7 may promote the migration and invasion of cervical cancer cells by epithelial-mesenchymal transition and exosome secretion.

Toxicity evaluation of zinc oxide nanoparticles in vitro and in vivo on cornea / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To observe the toxic effects of zinc oxide nanoparticles(ZnO NPs)on cornea by constructing intoxicated model in vivo and in vitro.METHODS:Human corneal epithelial cells(HCEpiC)were cultured in vitro and exposed to different concentrations(0.5, 5, 12.5, 25, 50, 100, 250 μg/mL)of ZnO NPs for 24h. The cell culture medium without nano-solution was used as the blank control group. The viability of the cells was assessed by MTT assay. Three different concentrations(25, 50 and 100 μg/mL)of ZnONPs dispersions were exposed to the conjunctival sac of anesthetized mice three times a day for 7d consecutively. The phosphate buffered saline(PBS)eye group was the PBS control group. Corneal morphology was observed on 1, 3, 5 and 7d, and the eyes were removed on 8d for various laboratory examinations, including corneal pathological changes and expression levels of inflammatory factors(TNF-α, IL-6).RESULTS:After treatment of HCEpiC cells with different concentrations of ZnO NPs for 24h, the MTT results showed that Zno NPs cause damage to cells at 0.5 μg/mL, and the cell survival rate was about 80%(P&#x003C;0.05). Half of the cells were killed at a dose of 5 μg/mL, the damaging effect on cells in the concentration range of 5～250 μg/mL was concentration-dependent(P&#x003C;0.0001). After 7d of conjunctival capsule spotting in mice, dot-like staining of fluorescein was seen in the 25 μg/mL ZnO NPs and 50 μg/mL ZnO NPs groups. Localized circular fluorescein stained areas were seen in the corneas of the 100 μg/mL ZnO NPs group. HE staining showed that the corneal epithelial layer, stromal layer thickness and stromal layer immune cell number did not change significantly in the 25 μg/mL and 50 μg/mL ZnO NPs groups(all P&#x003E;0.05), while the corneal epithelial layer thinned, the corneal stromal layer thickened and the stromal layer immune cells increased significantly in the 100 μg/mL ZnO NPs group(all P&#x003C;0.05). Immunohistochemical staining showed that the number of corneal stromal immune cells producing TNF-α and IL-6 and the mean integral optical density(IOD)values of TNF-α and IL-6 were significantly higher in the 100 μg/mL ZnO NPs group than in the PBS control group(P&#x003C;0.05), and the degree of inflammation response was concentration-dependent. Compared with the PBS control group, no significant increase in immune cell count and IOD values in the 25 μg/mL ZnO NPs and 50 μg/mL ZnO NPs groups(P&#x003E;0.05).CONCLUSION:The toxic damaging effect of ZnO NPs on the cornea was confirmed from both in vitro and in vivo, which provided a theoretical basis for the ocular safety evaluation of ZnO NPs.

Pseudomonas aeruginosa biofilm dispersion by the mouse antimicrobial peptide CRAMP.

Pseudomonas aeruginosa (P. aeruginosa) is a known bacterium that produces biofilms and causes severe infection. Furthermore, P. aeruginosa biofilms are extremely difficult to eradicate, leading to the development of chronic and antibiotic-resistant infections. Our previous study showed that a cathelicidin-related antimicrobial peptide (CRAMP) inhibits the formation of P. aeruginosa biofilms and markedly reduces the biomass of preformed biofilms, while the mechanism of eradicating bacterial biofilms remains elusive. Therefore, in this study, the potential mechanism by which CRAMP eradicates P. aeruginosa biofilms was investigated through an integrative analysis of transcriptomic, proteomic, and metabolomic data. The omics data revealed CRAMP functioned against P. aeruginosa biofilms by different pathways, including the Pseudomonas quinolone signal (PQS) system, cyclic dimeric guanosine monophosphate (c-di-GMP) signalling pathway, and synthesis pathways of exopolysaccharides and rhamnolipid. Moreover, a total of 2914 differential transcripts, 785 differential proteins, and 280 differential metabolites were identified. A series of phenotypic validation tests demonstrated that CRAMP reduced the c-di-GMP level with a decrease in exopolysaccharides, especially alginate, in P. aeruginosa PAO1 biofilm cells, improved bacterial flagellar motility, and increased the rhamnolipid content, contributing to the dispersion of biofilms. Our study provides new insight into the development of CRAMP as a potentially effective antibiofilm dispersant.

[Bacterial biofilms: novel strategies for intestinal colonization by probiotics].

Probiotics can improve the microecological balance of the body and have special effects in promoting nutrient absorption, controlling intestinal infections, and regulating immune function. However, there are problems such as difficult colonization in the gastrointestinal environment and low oral bioavailability. Bacterial biofilms are organized bacterial cells that adhere to an abiotic or biotic surface and are enclosed in extracellular polymeric substances of exopolysaccharides (EPS), extracellular DNA (eDNA), proteins and lipids, with a three-dimensional spatial structure. Probiotics with the help of bacterial biofilms have obvious advantages over planktonic bacteria in stress resistance, combating pathogens and modulating the host's immune function, which provides a new research idea for the development of probiotics. This paper expounded on the advantages of probiotics with the help of bacterial biofilms, and focused on introducing substances that could promote the formation of probiotic biofilms and the mechanisms, and the safety of probiotic biofilms. Currently, research on probiotic biofilms is still in its infancy, and this paper is expected to provide references for future research in this field.

[Using plant extracts and their active ingredients to inhibit bacterial biofilms].

Numerous studies have reported that the resistance of biofilm bacteria to antibiotics can be up to 10-1 000 fold higher than that of planktonic bacteria. Bacterial biofilms are reported to be responsible for more than 80% of human microbial infection, posing great challenges to the healthcare sector. Many studies have reported that plant extracts and their active ingredients can inhibit the formation and development of bacterial biofilms, including reducing biofilm biomass and the number of viable bacteria in biofilms, as well as eradicating mature biofilms. This review summarized the plant extracts and their active ingredients that are inhibitory to bacterial biofilms, and analyzed the underpinning mechanisms. This review may serve as a reference for the development of plant drugs to prevent and treat biofilm infections.

Characteristics of clinical and neuroimage findings in patients with corticobasal syndrome / 中华神经科杂志

Objective:To investigate the clinical, neuropsychological, and neuroimage characteristics in patients with corticobasal syndrome (CBS), and to elucidate the exact diagnosis of CBS patients.Methods:Twelve CBS cases admitted to the Department of Neurology, Huashan Hosiptal,Fudan University from April 2019 to July 2021 were retrospectively enrolled in this study. Those data, including clinical features (demographic data and clinical characteristics of cortical dysfunction and movement disorder), neuropsychological assessment [Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scales score], brain magnetic resonance imaging (MRI) and multi-mode positron emission tomography (PET)/CT, were collected and carefully reviewed. Exact diagnosis of these patients was given according to the disease diagnosis criteria.Results:Cortical dysfunction and asymmetrical movement disorders were found in all cases, with poor response to levodopa. Patients suffered from cognitive impairment (MMSE score 16.16±9.82, MoCA score 13.44±7.35). The cranial MRI demonstrated significant asymmetric atrophy of frontal and parietal lobes, especially in the pre- and post-central gyrus. Fluorodeoxyglucose PET of 12 patients showed asymmetric frontal lobe and basal ganglia (especially caudate and putamen) hypometabolism (obviously on the contralateral side of the affected limb). Tau PET was implemented in 11 patients and displayed that abnormal tau protein deposition was positive in the cortex and/or subcortex in all patients. Of the 4 cases, who completed amyloid PET, amyloid protein deposition was positive in the cortex of 2 patients. As a result, 6 patients were diagnosed as progressive supranuclear palsy, 1 patient was diagnosed as corticobasal degeneration, and 5 patients were diagnosed as Alzheimer′s disease.Conclusions:The etiology of CBS is heterogeneous. The combination of clinical manifestation, cranial MRI and multi-mode PET/CT helps the differential diagnosis of CBS.

Spinocerebellar ataxia type 11: a case report / 中华神经科杂志

Spinocerebellar ataxia (SCA) is a group of highly heterogeneous autosomal dominant genetic disease, including many subtypes. SCA11 is a rare subtype of SCA, and is caused by mutant TTBK2 gene. A case of SCA11 was reported in this article. Whole exome sequencing showed that there was a c.1284dupA frameshift mutation in TTBK2 gene. Literature review found that only 6 pedigrees of SCA11 have been reported, but the mutation site of this case is a novel identified mutation that has not been reported in the Human Gene Mutation Database.

Causal Relations between Exposome and Stroke: A Mendelian Randomization Study / 대한뇌졸중학회지

Background@#and Purpose To explore the causal relationships of elements of the exposome with ischemic stroke and its subtypes at the omics level and to provide evidence for stroke prevention. Methods We conducted a Mendelian randomization study between exposure and any ischemic stroke (AIS) and its subtypes (large-artery atherosclerotic disease [LAD], cardioembolic stroke [CE], and small vessel disease [SVD]). The exposure dataset was the UK Biobank involving 361,194 subjects, and the outcome dataset was the MEGASTROKE consortium including 52,000 participants. @*Results@#We found that higher blood pressure (BP) (systolic BP: odds ratio [OR], 1.02; 95% confidence interval [CI], 1.01 to 1.04; diastolic BP: OR, 1.03; 95% CI, 1.01 to 1.05; pulse pressure: OR, 1.03; 95% CI, 1.00 to 1.06), atrial fibrillation (OR, 1.18; 95% CI, 1.13 to 1.25), and diabetes (OR, 1.13; 95% CI, 1.07 to 1.18) were significantly associated with ischemic stroke. Importantly, higher education (OR, 0.69; 95% CI, 0.60 to 0.79) decreased the risk of ischemic stroke. Higher systolic BP (OR, 1.06; 95% CI, 1.02 to 1.10), pulse pressure (OR, 1.08; 95% CI, 1.02 to 1.14), diabetes (OR, 1.28; 95% CI, 1.13 to 1.45), and coronary artery disease (OR, 1.58; 95% CI, 1.25 to 2.00) could cause LAD. Atrial fibrillation could cause CE (OR, 1.90; 95% CI, 1.71 to 2.11). For SVD, higher systolic BP (OR, 1.04; 95% CI, 1.00 to 1.07), diastolic BP (OR, 1.06; 95% CI, 1.01 to 1.12), and diabetes (OR, 1.22; 95% CI, 1.10 to 1.36) were causal factors. @*Conclusions@#The study revealed elements of the exposome causally linked to ischemic stroke and its subtypes, including conventional causal risk factors and novel protective factors such as higher education.

Research advances of small molecule inhibitors in the treatment of mixed lineage leukemia / 药学学报

Acute leukemia (AL) is a kind of malignant clonal disease of hematopoietic stem cells. Rearrangement of mixed lineage leukemia (MLL) gene can be observed in about 5%-10% of AL patients. Currently, AL patients with MLL-rearrangements (MLL-r) lack effective treatment and are usually associated with poor prognoses. Recent studies have shown that many epigenetic regulators are directly or indirectly involved in the occurrence and development of AL carrying MLL-r (MLL), which provides a biological basis for the use of epigenetic regulation strategies to treat MLL. In this review, we start from the epigenetic regulation mechanism of MLL, and select representative drug targets to briefly analyze the relationship between each target and MLL and summarize the development progress of their inhibitors, hoping to provide reference for the subsequent research and development of drugs for the treatment of MLL.

Progress of functional cognitive disorder / 中华神经科杂志

Functional cognitive disorder (FCD) refers to complaints of persistent problematic cognitive decline, which is inconsistent between self-reported symptoms and daily function and/or neuropsychological test results, and the symptoms lasted for at least six months without obvious progress. Poor ability to reflect on and monitor cognitive processes has been suggested as a key mechanism underlying the disorder. In this review, the concept, research status, clinical manifestations and diagnosis of FCD were systematically examined, which is helpful to identify the subjective cognitive decline caused by non-degenerative diseases and conduct individualized intervention treatment.

Methylation status and expression of TWEAK gene promoter region in peripheral blood of patients with rheumatoid arthritis / 北京大学学报(医学版)

OBJECTIVE@#To explore the relationship between tumor necrosis factor like weak inducer of apoptosis (TWEAK) gene and the pathogenesis of rheumatoid arthritis (RA) by detecting the DNA methylation level, mRNA expression level and serum protein concentration of TWEAK gene in peripheral blood.@*METHODS@#The MassARRAY method was used to detect the DNA methylation level of the TWEAK gene in the peripheral blood of 112 RA patients and 86 matched healthy volunteers. The real-time quantitative polymerase chain reaction method was used to detect the mRNA expression level of the TWEAK gene in the peripheral blood of the subjects. The enzyme-linked immunosorbent assay method was used to detect the serum TWEAK protein concentration of the subjects. The TWEAK gene DNA methylation level, mRNA expression level and serum protein concentration between the RA group and the healthy control group were compared, and the relationship between it and the degree of disease activity analyzed.@*RESULTS@#The overall DNA methylation level of TWEAK gene and the DNA methylation levels of CpG_11, CpG_17.18.19.20, CpG_40.41.42 site in the RA group were higher than those in the healthy control group (P=0.002, P=0.01, P=0.006, P=0.002, respectively). The DNA methylation level of CpG_55.56 site in the high disease activity group was higher than that in the medium and low disease activity group (P=0.041). The expression level of TWEAK gene mRNA in the peripheral blood of the RA group was lower than that of the healthy control group (P=0.023). The expression level of TWEAK gene mRNA in the high disease activity group was lower than that in the medium and low disease activity group (P=0.035). The serum TWEAK protein concentration of the RA group was not significantly different from that of the healthy control group (P=0.508), but it was positively correlated with the mRNA expression level (r=0.482, P < 0.001).@*CONCLUSION@#The TWEAK gene is closely related to the onset and progression of RA, and its hypermethylation state may be one of the epigenetic mechanisms regulating its low mRNA expression, and it can be used as one of the important indicators for clinical monitoring and evaluation of RA.

Historical evolution and research advance in processing adjuvant--vinegar / 中国中药杂志

Processing of Chinese medicinals with vinegar is one of the characteristic processing techniques. Vinegar is vital for the quality of vinegar-processed decoction pieces. However, there have been no specified standards for adjuvants. Through consulting relevant literature and monographs, we comprehensively reviewed the historical evolution of processing with vinegar in records, selection and application of vinegar, and summarized the relevant standards and current status of vinegar as an adjuvant in China. According to the records in literature, vinegar is effective in activating blood, moving qi, dispersing blood stasis, removing toxin, promoting appetite, and nourishing the liver. Traditionally, rice vinegar is chosen in processing. Nowadays, the vinegar made from rice under solid-state fermentation should be chosen. At present, only food standards can be taken for reference for vinegar in the processing. Integrative and specific inspection indicators are lacking, so the standards for adjuvants need to be improved urgently. In addition, the inadequacy in quality control and management is also a major problem to be solved. Through literature research, we reviewed the historical evolution and research advance in vinegar to provide a reference for the standardization and further research of vinegar used in the Chinese medicinal processing.

L-Arginine protects mouse Leydig cells against T-2 toxin-induced apoptosis in vitro.

To explore the protective mechanism of L-arginine against T-2 toxin-induced apoptosis in mouse Leydig cells, we investigated whether L-arginine can prevent T-2 toxin-induced apoptosis in mouse Leydig cells and explored the underlying mechanisms. Leydig cells were isolated and cultured with control, T-2 toxin (10 nM), L-arginine (0.25, 0.5, and 1.0 mM), and T-2 toxin (10 nM T-2 toxin) + L-arginine (0.25, 0.5, or 1.0 mM) for 24 h. Cells and supernatants were harvested to examine proliferation of the cells, the apoptosis rate, activity of caspase-3 and mitochondria, and the gene expression levels of Bcl-2, Bax, PARP, and caspase-3. Results showed that proliferation and mitochondrial activity of Leydig cells were inhibited by administration of T-2 toxin. Bcl-2 gene expression levels was decreased, while the gene expression levels of Bax and PARP were increased, which could trigger mitochondria-mediated apoptosis, activate downstream caspase-3, and then increased caspase-3 at both activity and gene expression levels. The expression of the Bcl-2 gene was upregulated and the expression of Bax, caspase-3, and PARP gene were downregulated when L-arginine was added to the cultured cells. The results of this study showed that L-arginine could block T-2 toxin-induced apoptosis in mouse Leydig cells by regulating specific intracellular death-related pathways.