Rutin supplementation in the diet has protective effects against toxicant-induced hippocampal injury by suppression of microglial activation and pro-inflammatory cytokines: protective effect of rutin against toxicant-induced hippocampal injury.
OBJECTIVE
Rutin is one of the flavonoids that has many beneficial effects on the health. Previously, we showed that rutin has a protective effect on trimethyltin (TMT)-induced memory dysfunction in rats. The aim of this study was to investigate the protective effects of rutin on TMT-induced hippocampal injury and the time course profiles of these effects in rats.


METHODS
Four-week-old male Sprague-Dawley (SD) rats were fed chow with or without rutin (0.75%) during the experimental period and were administered with a single dose of TMT (8.5 mg/kg b.w., p.o.) or vehicle at 6 weeks of age. The rats were sacrificed 5, 10, or 20 days after the TMT administration and then histological and molecular examinations of the hippocampus were performed.


RESULTS
Rutin supplementation suppressed the TMT-induced decrease in the number of hippocampal pyramidal neurons 20 days after TMT administration. The TMT-induced up-regulation of the mRNA expression levels of reactive microglia marker and pro-inflammatory cytokines were reversed by rutin supplementation 10 or 20 days after the TMT administration.


CONCLUSIONS
These results suggested that the neuroprotective effect of rutin on TMT-induced spatial memory impairment could be attributable to its inhibitory effect against microglial activation and its role in synapse formation via neurotrophic factors in the hippocampus.
Koda
Tomoko
T
Division of Environmental Health Sciences, Department of Social Medicine, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki, Japan.
Kuroda
Yoshiki
Y
Imai
Hideki
H
D000818:Animals; D001835:Body Weight; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D004032:Diet; D019587:Dietary Supplements; D004435:Eating; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000473:pathology; D007249:Inflammation / Q000378:metabolism*; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced / Q000517:prevention & control; D017628:Microglia / Q000378:metabolism*; D009414:Nerve Growth Factors / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000187:drug effects; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012431:Rutin / Q000008:administration & dosage / Q000494:pharmacology; D014298:Trimethyltin Compounds / Q000633:toxicity
D016207:Cytokines; D009414:Nerve Growth Factors; D018696:Neuroprotective Agents; D014298:Trimethyltin Compounds; C046488:trimethyltin; D012431:Rutin