紫贻贝金属硫蛋白对小鼠体内镉富集的拮抗及排出功效研究

Antagonism and elimination effects of metallothionein from Mytilus edulis on accumulation of cadmium in mice

中文关键词:  金属硫蛋白  镉  生理指标  氧化应激  肠道菌群

英文关键词:metallothionein  cadmium  physiological properties  oxidative stress  intestinal microbiota

中文摘要:

      目的 考察紫贻贝金属硫蛋白(metallothionein, MT)对小鼠体内Cd2+的拮抗及排除功效。方法 采用0.5 mg/L CdCl2饲喂小鼠, 建立Cd2+染毒小鼠模型; 设立正常对照、CdCl2模型、MT(50、75、100 mg/(kg?d))和依地酸二钠钙(75 mg/(kg?d))组, 连续给药3 d、停止4 d, 持续30 d后, 分析小鼠生理指标、Cd2+含量、抗氧化能力及肠道菌群组成。结果 与正常组相比, 模型小鼠体重、肝脏和脾脏重量及其系数显著降低(P<0.05), 依地酸二钠钙和较高剂量MT给药, 表现出显著改善小鼠生理指标作用。模型小鼠全血、肝脏及骨中Cd2+含量显著增加(P<0.05), 依地酸二钠和MT给药对体内Cd2+排除显著(P<0.05)。相比正常组和模型组, MT对小鼠体内总抗氧化能力(total antioxidant capacity, T-AOC)和丙二醛(malondialdehyde, MDA)含量具有显著改善作用(P<0.05)。与正常组相比, Cd2+染毒显著影响小鼠肠道正常菌群关系, 造成菌群丰度和多样性减少; 而MT对染毒小鼠肠道菌群结构、微生物多样性及丰度, 均具有一定恢复作用。结论 MT具有拮抗Cd2+体内富集及排出功效, 其机制可能通过修复Cd2+氧化损伤、减少过氧化产物水平及调节肠道菌群结构等途径实现。

英文摘要:

      Objective To investigate the antagonism and elimination effects of metallothionein (MT) from Mytilus edulis on accumulation of cadmium (Cd) in mice. Methods The model of mice with high concentrations of Cd in vivo was established with 0.5 mg/L CdCl2 feeding. The mice were randomly divided into 6 groups including the blank control group, the model group, the groups treated with MT at different doses (50, 75, 100 mg/(kg?d)), and calcium disodium edetate group (75 mg/(kg?d)). After 30 days of administration, the Cd concentrations, some physiological properties, antioxidant capacities, and intestinal microbiota in mice were evaluated, respectively. Results The results were indicated that the weight, liver coefficient, and spleen coefficient of the model mice was significantly decreased after the administration (P<0.05). For comparison, the treatments of alcium disodium edetate and high dose of MT significantly improved the above physiological properties (P<0.05). The concentrations of Cd in the whole blood, liver and bone in model mice were increased significantly, while the calcium disodium edetate and MT administrations significantly eliminated the Cd from the organisms (P<0.05). The similar results were also found in the capacities of oxidative stress (T-AOC activity and MDA concentration) in vivo. In addition, the Cd exposure affected the intestinal microbiota diversity of the mice, resulting in reducing of abundance and diversity of intestinal microbiota. However, the MT administration significantly improved the structure, diversity and abundance of the intestinal species, compared to the mice fed Cd diet. Conclusion For these reasons, MT can be recommended as a supplement in feed to decrease the concentrations of Cd in vivo, the effects of which might be achieved by MT through the improvement of the physiological properties, oxidative stress, and the intestinal microbiota.