Oyster (Crassostrea gigas) contains abundant nutritional elements, including glycogen, vitamine, zinc and taurine. It is reported that oyster extract exhibited several physiological activities．One of the factors is considered to be the glutathione-increasing effect of oyster extract administration. Here we report the effect of oyster extract on the gastrointestinal and myeloid toxicity of 5-FU in rats and its relationship with the glutathione-increasing effect.
Male SD rats were used in this study. Test groups were as follow, control, 5-FU, 5-FU and oyster extract (200 and 500 mg/kg/days). Oyster extracts were administrated for 21 days in rats. 5-FU was administrated for 5 days after 14 days of oyster extracts administrated. After termination of administration of oyster extracts, recovery period was established for 3 days, and autopsy was performed.
No deaths were observed throughout the study period. Evaluation of intestinal mucosa by histopathological examination, mucosal thickness, villous height and crypt thickness were dose - dependent or high trend without dose - dependence. In addition, a suppression tendency was also observed for mucosal atrophy of the duodenum due to administration of 5-FU. From the above results, it was suggested that oyster extract is effective in alleviating gastrointestinal toxicity by 5-FU.
We have reported that the toxicity of rats by administration of 5-FU to the gastrointestinal tract and bone marrow is suppressed by administration of N-acetylcysteine, and a glutathione-increasing effect has been shown as a mechanism. This time, the toxicity-reducing effect obtained by the administration of oyster extract is also considered to be based on the glutathione-increasing effect.