Isolation of a Lysinibacillus fusiformis strain with tetrodotoxin-producing ability from puffer fish Fugu obscurus and the characterization of this strain

Six dominant strains were isolated from the livers of the puffer fish Fugu obscurus and were screened for their TTX production-ability. Electrospray ionization-mass spectrometry (ESI-MS) analyses revealed that strain B-1 produced TTX and related substances; mouse bioassay revealed that 23.9 mouse units (MU) of toxins were present in 200 ml of broth medium. On the basis of the physiological and biochemical characteristics of this strain and the results of 16S rRNA analysis, strain B-1 was identified as Lysinibacillus fusiformis.     

Renoprotective Effect of Spirulina fusiformis on Cisplatin-Induced Oxidative Stress and Renal Dysfunction in Rats

Cisplatin is an effective chemotherapeutic agent used in the treatment of a wide array of both pediatric and adult malignancies. Dose-dependent and cumulative nephrotoxicity is the major toxicity of this compound, sometimes requiring a reduction in dose or discontinuation of treatment. Recent evidences have implicated oxidative and nitrosative stress in cisplatin-induced nephrotoxicity. Spirulina fusiformis, blue-green algae, is claimed to be a potential antioxidant. The present study was designed to explore the renoprotective potential of Spirulina fusiformis against cisplatin-induced oxidative stress and renal dysfunction. Spirulina fusiformis (500,1000,1500 mg/kg^?1 p.o.) was administered 2 days before and until 3 days after cisplatin challenge (5 mg/kg^?1 i.p.). Renal injury was assessed by measuring serum creatinine, blood urea nitrogen, creatinine and urea clearance, and serum nitrite levels. Renal oxidative stress was determined by renal TBARS levels, reduced glutathione levels, and by enzymatic activity of superoxide dismutase and catalase. A single dose of cisplatin produced marked renal oxidative and nitrosative stress and significantly deranged renal functions. Chronic Spirulina fusiformis treatment significantly and dose-dependently restored renal functions, reduced lipid peroxidation, and enhanced reduced glutathione levels, superoxide dismutase, and catalase activities. The results of the present study clearly demonstrate the pivotal role of reactive oxygen species and their relation to renal dysfunction and point to the therapeutic potential of Spirulina fusiformis in cisplatin-induced nephrotoxicity.     

羊栖菜对四氧嘧啶糖尿病模型小鼠血糖水平影响

目的探讨羊栖菜对四氧嘧啶糖尿病小鼠血糖水平的影响及其机制。方法成年健康雄性昆明小鼠50只,随机取10只作为对照组,其余40只腹腔注射四氧嘧啶建立高糖血症动物模型,将基础空腹血糖(FBG)为10.00~15.00 mmol/L的24只小鼠随机分为模型组、二甲双胍组、羊栖菜组,每组8只。羊栖菜组小鼠给予羊栖菜粉饲料继续喂养2周;二甲双胍组小鼠普通饲料喂养,二甲双胍灌胃,每日1次,共2周;对照组和模型组普通饲料喂养2周。自动血糖仪测小鼠FBG,硫代巴比妥酸法和硝酸还原酶法分别检测脂质过氧化物丙二醛(MDA)和一氧化氮(NO)含量,黄嘌呤氧化酶法和化学比色法分别测定超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-PX)活性。结果治疗后羊栖菜组和二甲双胍组小鼠血清FBG、MDA和NO水平均较模型组显著降低(F=6.11~112.95,q=3.46~10.61,P<0.05),而SOD和GSH-PX活性均显著高于模型组(F=9.08、5.76,q=4.52~5.34,P<0.05)。结论羊栖菜可能通过增强SOD和GSH-PX的活性,降低体内MDA和NO的水平,发挥调节血糖水平的作用。     

羊栖菜对实验性高脂血症大鼠血脂水平的调节作用

目的 探讨羊栖菜对高脂血症大鼠血脂的调节作用.方法 健康雌性Wistar大鼠40只,高脂饲料喂养建立高脂血症动物模型,羊栖菜粉饲料喂养干预治疗.生化法检测大鼠血清甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白(LDL)、高密度脂蛋白(HDL)水平及脂蛋白酯酶(LPL)和肝脂酶(HL)活性.酶联免疫吸附法测定羟甲基戊二...     

尖山橙枝叶化学成分研究

目的研究尖山橙Melodinus fusiformis枝叶非生物碱部位的化学成分。方法采用柱色谱进行分离,通过理化性质和光谱数据鉴定结构。结果从尖山橙枝叶甲醇提取物的醋酸乙酯部位分离得到28个化合物,分别鉴定为oleanderolide(1)、麦珠子酸(2)、3β-acetoxylup-20(29)-ene(3)、11,12-去氢乌索酸内酯(4)、齐墩果内酯(5)、24R-乙基-5α-胆甾烷-3β,6α-二醇(6)、(+)-松脂酚(7)、8α-羟基松脂酚(8)、番木鳖苷A(9)、紫云英苷(10)、α-tocopherol(11)、butyl isobutyl phthalate(12)、11-羟基柳叶水甘草碱(13)、(+)-voaphylline(14)、丁香树脂酚(15)、(+)-1-羟基丁香树脂酚(16)、(+)-fraxiresinol(17)、1-(4-hydroxy-3,5-dimethoxyphenyl)-hexahydro-1H-cyclopentafuran-4-o(l 18)、(±)-acyloxy enone(19)、2-羟基苯甲酸(20)、邻苯二甲酸二丁酯-N,N-二乙基-2-羟基苯甲酰胺(21)、6-羟基吲哚(22)、1,3-二油酸甘油酯(23)、邻苯二甲酸二丁酯(24)、双(2-乙基丁基)对苯二甲酸酯(25)、(6Z,8E,17E)-icosa-6,8,17-trien-lo-ol(26)、β-谷甾醇(27)、乌索酸(28)。结论尖山橙化学成分复杂多样,所分离的成分中有26个化合物(1～12、15～28)为首次从该植物中获得。     

Cytotoxic Effects and Intracellular Localization of Bin Toxin from Lysinibacillus sphaericus in Human Liver Cancer Cell Line

Binary toxin (Bin toxin), BinA and BinB, produced by Lysinibacillus sphaericus has been used as a mosquito-control agent due to its high toxicity against the mosquito larvae. The crystal structures of Bin toxin and non-insecticidal but cytotoxic parasporin-2 toxin share some common structural features with those of the aerolysin-like toxin family, thus suggesting a common mechanism of pore formation of these toxins. Here we explored the possible cytotoxicity of Bin proteins (BinA, BinB and BinA + BinB) against Hs68 and HepG2 cell lines. The cytotoxicity of Bin proteins was evaluated using the trypan blue exclusion assay, MTT assay, morphological analysis and LDH efflux assay. The intracellular localization of Bin toxin in HepG2 cells was assessed by confocal laser scanning microscope. HepG2 cells treated with BinA and BinB (50 µg/mL) showed modified cell morphological features and reduced cell viability. Bin toxin showed no toxicity against Hs68 cells. The EC₅₀ values against HepG2 at 24 h were 24 ng/mL for PS2 and 46.56 and 39.72 µg/mL for BinA and BinB, respectively. The induction of apoptosis in treated HepG2 cells was confirmed by upregulation of caspase levels. The results indicated that BinB mediates the translocation of BinA in HepG2 cells and subsequently associates with mitochondria. The study supports the possible development of Bin toxin as either an anticancer agent or a selective delivery vehicle of anticancer agents to target mitochondria of human cancer cells in the future.     

Effect of Spirulina, a blue green algae, on gentamicin-induced oxidative stress and renal dysfunction in rats

Gentamicin (GM), an aminoglycoside, is widely employed in clinical practice for the treatment of serious Gram-negative infections. The clinical utility of GM is limited by the frequent incidence of acute renal failure. Experimental evidences suggest that oxidative and nitrosative stress play an important role in GM nephrotoxicity. Spirulina fusiformis is a blue green algae with potent free radical scavenging properties. The present study was designed to investigate renoprotective potential of S. fusiformis, against GM-induced oxidative stress and renal dysfunction. Spirulina fusiformis (500, 1000, 1500 mg/kg, p.o.) was administered 2 days before and 8 days concurrently with GM (100 mg/kg, i.p.). Renal injury was assessed by measuring serum creatinine, blood urea nitrogen and creatinine clearance and serum nitrite levels. Renal oxidative stress was determined by renal malondialdehyde levels, reduced glutathione levels and by enzymatic activity of superoxide dismutase (SOD) and catalase. Chronic GM administration resulted in marked renal oxidative and nitrosative stress and significantly deranged renal functions. Treatment with S. fusiformis significantly and dose-dependently restored renal functions, reduced lipid peroxidation and enhanced reduced glutathione levels, SOD and catalase activities. The results of present study clearly demonstrate the pivotal role of reactive oxygen species and their relation to renal dysfunction and point to the therapeutic potential of S. fusiformis in GM-induced nephrotoxicity.