Hydrogen sulfide attenuates lipopolysaccharide-induced cognitive impairment: a pro-inflammatory pathway in rats

The present study investigated the effect of sodium hydrosulfide (NaHS), a H(2)S donor, on cognitive impairment and neuroinflammatory changes induced by bilateral intracerebroventricular injections of LPS at a dose of 10mug/rat. Rats received 5mg/kg NaHS or volume-matched vehicle administration by intraperitoneal injection 3days before LPS injection then for 9days once daily. Morris water maze was used to detect the cognitive function. Compared to the sham-treated rats, LPS injection significantly prolonged the mean escape latency in the navigation test (P<0.05) and shortened the adjusted escape latency by approximately 30% (P<0.05). Meanwhile, LPS injection decreased H(2)S level but increased pro-inflammatory mediators (i.e., TNF-alpha, TNFR1, degradation of IkappaB-alpha and thereafter activation of NF-kappaB) in hippocampus. However, these effects of LPS were significantly ameliorated with NaHS treatment (P<0.05 vs vehicle-treated group). The present data suggest that H(2)S attenuates LPS-induced cognitive impairment through reducing the overproduction of pro-inflammatory mediators via inhibition of NF-kappaB pathways in rats. This study sets the stage for exploring a novel H(2)S releasing agent for preventing or retarding the development or progression of neurological disorders such as Alzheimer's disease.