Antioxidant capacity and concentration of redox-active trace mineral in fully weaned intra-uterine growth retardation piglets

Background： The redox status of intra-uterine growth retardation（IUGR） piglets post-weaning has been poorly studied.Methods： Newborns from twenty-four sows were weighted, weaned at 21 d and fed a starter diet until sampling.Sampling was done at 14 d post-weaning. A piglet was defined as IUGR when its birth weight was 2 SD below the mean birth weight of the total population. At weaning, eighteen piglets with nearly equal body weight from each category（i.e. IUGR or normal birth weight（NBW） piglets） were selected and then allocated to two treatments,consisted of six replicates with each pen having three piglets.Results： Compared with NBW group, IUGR significantly decreased average daily gain（P 〈 0.001）, average daily feed intake（P = 0.003）, and feed efficiency（P 〈 0.001） of piglets during the first two weeks post-weaning. IUGR decreased the activities of total antioxidant capacity（P = 0.019）, total superoxide dismutase（T-SOD, P = 0.023）,and ceruloplasmin（P = 0.044） but increased the levels of malondialdehyde（P = 0.040） and protein carbonyl（P = 0.010） in plasma. Similarly, the decreased activities of T-SOD（P = 0.005）, copper- and zinc-containing superoxide dismutase（Cu/Zn-SOD, P = 0.002）, and catalase（P = 0.049） was observed in the liver of IUGR piglets than these of NBW piglets. IUGR decreased hepatic Cu/Zn-SOD activity（P = 0.023） per unit of Cu/Zn-SOD protein in piglets when compared with NBW piglets. In addition, IUGR piglets exhibited the decreases in accumulation of copper in both plasma（P = 0.001） and liver（P = 0.014）, as well as the concentrations of iron（P = 0.002） and zinc（P = 0.048） in liver. Compared with NBW, IUGR down-regulated m RNA expression of Cu/Zn-SOD（P = 0.021） in the liver of piglets.Conclusions： The results indicated that IUGR impaired antioxidant capacity and resulted in oxidative damage in fully weaned piglets, which might be associated with the decreased levels of redox-active trace minerals. This study highlights the importance of redox status in IUGR offspring and provides a rationale for alleviating oxidative damage by dietary interventions aiming to supplement trace minerals and to restore redox balance in the future.

Growth inhibition and oxidative damage of Microcystis aeruginosa induced by crude extract of Sagittaria trifolia tubers

Aquatic macrophytes are considered to be promising in controlling harmful cyanobacterial blooms. In this research, an aqueous extract of Sagittaria trifolia tubers was prepared to study its inhibitory effect on Microcystis aeruginosa in the laboratory. Several physiological indices of M. aeruginosa, in response to the environmental stress, were analyzed. Results showed that S. trifolia tuber aqueous extract significantly inhibited the growth of M. aeruginosa in a concentration-dependent way. The highest inhibition rate reached 90% after 6 day treatment. The Chlorophyll-a concentration of M. aeruginosa cells decreased from 343.1 to314.2 μg/L in the treatment group. The activities of superoxide dismutase and peroxidase and the content of reduced glutathione in M. aeruginosa cells initially increased as a response to the oxidative stress posed by S. trifolia tuber aqueous extract, but then decreased as time prolonged. The lipid peroxidation damage of the cyanobacterial cell membranes was reflected by the malondialdehyde level, which was notably higher in the treatment group compared with the controls. It was concluded that the oxidative damage of M. aeruginosa induced by S.trifolia tuber aqueous extract might be one of the mechanisms for the inhibitory effects.