Protective effect of Dictyophora polysaccharide on neurotoxicity induced by sodium arsenite in rats / 中华地方病学杂志

ABSTRACT

Objective:To investigate the protective effect of Dictyophora polysaccharide on neurotoxicity induced by sodium arsenite in rats.Methods:Sixty SD rats (half males and half females) were selected and fed adaptively for one week. The rats were divided into a normal group ( n = 20, ordinary feed) and a modeling group [ n = 40, arsenic-containing feed (50 mg/kg sodium arsenite)] according to their body weight (80 - 100 g) by random number table method. After 12 weeks, the arsenic content in brain and blood of the rats ( n = 10) was measured to identify the arsenism model. After successful modeling, the rats in the modeling group were divided into Dictyophora polysaccharide group (arsenic-containing feed + 20 ml·kg -1·bw Dictyophora polysaccharide solution by gavage), and model group (arsenic-containing feed + equal volume distilled water by gavage), while the rats in the normal group (ordinary feed + equal volume distilled water by gavage) were retained, with 10 rats in each group for 4 weeks of intervention. Morris water maze test was used to assess the spatial learning and memory ability of the rats. Nissl staining was used to observe the pathological changes of the brain tissue, and the oxidative stress factors [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA)], and inflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukin -1β (IL-1β)] in the brain tissue of each group were measured. Results:Brain arsenic content of rats in the modeling group [(92.02 ± 13.37) μg/g] and blood arsenic content [(51.37 ± 19.33) μg/L] were higher than those of the normal group [(7.42 ± 3.21) μg/g and (2.74 ± 1.29) μg/L, t = - 6.91, - 6.06, P < 0.001]. The rat model of arsenic poisoning was successfully established. Compared with the normal group, the escape latency on the 1st, 3rd and 4th day and the first arrival time of rats in the model group were prolonged, the number of platform crossings was reduced, and the proportion of target quadrant residence time was decreased ( P < 0.05). Compared with the model group, the escape latency on the 4th day and the first arrival time of rats in the Dictyophora polysaccharide group were shortened, and the proportion of target quadrant residence time was prolonged ( P < 0.05). The results of Nissl staining showed that compared with the normal group, the number of Nissl bodies was decreased, the intercellular space increased, and the arrangement was disorderly in the model group; compared with the model group, the number of Nissl bodies was increased, most of the neurons were structurally intact. Compared with the normal group, the levels of SOD and GSH-Px in the brain tissue of rats in the model group were lower, and the levels of MDA, TNF-α and IL-1β were significantly higher ( P < 0.05). Compared with the model group, the levels of SOD and GSH-Px in the brain tissue of rats in the Dictyophora polysaccharide group were higher, while the levels of MDA, TNF-α and IL-1β were lower ( P < 0.05). In addition, the levels of SOD, GSH-Px, MDA and IL-1β in the Dictyophora polysaccharide group were not significantly different from those in the normal group ( P > 0.05). Conclusion:Diactyophora polysaccharide probably reduces the neurotoxicity damage caused by sodium arsenite in rats through antioxidant and antiinflammatory effects.