In this study, we isolated a polysaccharide from Branchiostoma belcheri （PBB） by enzymatic protein hydrolysis and alcohol precipitation. We investigated the effects of PBB supplementation on DNA oxidation and growth...In this study, we isolated a polysaccharide from Branchiostoma belcheri （PBB） by enzymatic protein hydrolysis and alcohol precipitation. We investigated the effects of PBB supplementation on DNA oxidation and growth of the transplanted tumor cells Sarcoma （S180） in mice. Sixty healthy Kunming mice weighing between 18 and 25 g were randomly assigned to 6 groups, each consisting of 10 animals. All the mice, except for the blank control group, were inoculated with S180 sarcoma cells into the axilla of the left foreleg. PBB was given to mice by gavage at doses of 0 （model control）, 25, 50, or 100 mg/kg b.w. in 0.2 ml saline for 30 days. The fifth group of S180-mice was given cytoxan （50 mg/kg） by peritoneal injection as a positive control group. The animals had free access to food and water. The mice were sacrificed after the final treatment and blood was quickly collected. Spontaneous and oxidized DNA damage of peripheral lymphocytes induced by H2O2 were analyzed by SCGE. O6-methyl-guanine （O6-MeG） was measured by high-performance capillary zone electrophoresis. The average tumor weights （0.856-1.118 g） of the three PBB groups were significantly lower than that of the model control group （1.836 g） （p〈0.05）. The tumor inhibition ratios of the PBB groups were 39.1%-53.4% and similar to the cytoxan positive group （57.5%）. There were no significant differences in spontaneous DNA damage in peripheral lymphocytes among the groups. The oxidative DNA damage induced by 10 μmol/L H2O2 in the 50 and 100 mg/kg b.w. groups were 246.1 AU and 221.7 AU, respectively, both of which were significantly lower than that in the model group （289.0 AU; p〈0.05）. The plasma concentrations of O6-MeG in the 25, 50, and 100 mg/kg supplemented groups were 2.09 μmol/L, 1.86 μmol/L, and 1.63 lamol/L, respectively, all of which were significantly lower than that of the model group （2.67 μmol/L; p〈0.05）. These results indicated that PBB may have antioxidative activity and thus reduce oxidation-induced DNA damage.展开更多
生乳易受沙门氏菌污染,并大量繁殖;经加工的乳制品细菌数大大减少,但仍存在沙门氏菌污染的风险。试验按生乳及乳制品沙门氏菌污染水平研究样品前处理方法,采用煮沸裂解法快速提取总DNA,针对沙门氏菌invA基因建立SYBR Green Ⅰ荧光定量PC...生乳易受沙门氏菌污染,并大量繁殖;经加工的乳制品细菌数大大减少,但仍存在沙门氏菌污染的风险。试验按生乳及乳制品沙门氏菌污染水平研究样品前处理方法,采用煮沸裂解法快速提取总DNA,针对沙门氏菌invA基因建立SYBR Green Ⅰ荧光定量PCR快速检测技术。建立的方法具有良好的特异性和较高的灵敏度,其中生乳沙门氏菌检出限为102cfu.mL-1,方法的检测线性范围为102～108cfu.mL-1,相关系数(R2)为0.999,扩增效率为103%;乳制品沙门氏菌经16 h增菌后检出限达到1 cfu.[25 g(mL)]-1。该技术可用于生乳中沙门氏菌的高效筛查及定量检测,检测一个样品仅需3 h;同时,可用于乳制品的准确定性检测,检测周期为1 d;且方法重复性好、准确度高、操作简单,为乳制品企业快速检测沙门氏菌提供了有效的技术手段。展开更多
文摘In this study, we isolated a polysaccharide from Branchiostoma belcheri （PBB） by enzymatic protein hydrolysis and alcohol precipitation. We investigated the effects of PBB supplementation on DNA oxidation and growth of the transplanted tumor cells Sarcoma （S180） in mice. Sixty healthy Kunming mice weighing between 18 and 25 g were randomly assigned to 6 groups, each consisting of 10 animals. All the mice, except for the blank control group, were inoculated with S180 sarcoma cells into the axilla of the left foreleg. PBB was given to mice by gavage at doses of 0 （model control）, 25, 50, or 100 mg/kg b.w. in 0.2 ml saline for 30 days. The fifth group of S180-mice was given cytoxan （50 mg/kg） by peritoneal injection as a positive control group. The animals had free access to food and water. The mice were sacrificed after the final treatment and blood was quickly collected. Spontaneous and oxidized DNA damage of peripheral lymphocytes induced by H2O2 were analyzed by SCGE. O6-methyl-guanine （O6-MeG） was measured by high-performance capillary zone electrophoresis. The average tumor weights （0.856-1.118 g） of the three PBB groups were significantly lower than that of the model control group （1.836 g） （p〈0.05）. The tumor inhibition ratios of the PBB groups were 39.1%-53.4% and similar to the cytoxan positive group （57.5%）. There were no significant differences in spontaneous DNA damage in peripheral lymphocytes among the groups. The oxidative DNA damage induced by 10 μmol/L H2O2 in the 50 and 100 mg/kg b.w. groups were 246.1 AU and 221.7 AU, respectively, both of which were significantly lower than that in the model group （289.0 AU; p〈0.05）. The plasma concentrations of O6-MeG in the 25, 50, and 100 mg/kg supplemented groups were 2.09 μmol/L, 1.86 μmol/L, and 1.63 lamol/L, respectively, all of which were significantly lower than that of the model group （2.67 μmol/L; p〈0.05）. These results indicated that PBB may have antioxidative activity and thus reduce oxidation-induced DNA damage.
