米糠脂多糖的免疫增强作用及安全性评价

目的：米糠脂多糖是新发现的一种植物脂多糖，未曾进行过生物试验。本研究探讨米糠脂多糖和大肠杆菌来源的细菌脂多糖的一些免疫增强作用及其安全性。方法：观察米糠脂多糖对小鼠脾指数和肿瘤坏死因子（ＴＮＦ）的影响，以及急性毒性试验。结果：在相同剂量（２５００μｇ·ｋｇ－１·ｄ－１）条件下仅１周实验后，米糠脂多糖组和大肠杆菌０１１１∶Ｂ４脂多糖组动物的脾指数都能显著提高（Ｐ＜０．０１）；在激活网状内皮系统产生ＴＮＦ方面，在相同剂量（２５００μｇ·ｋｇ－１·ｄ－１）条件下，米糠脂多糖组的ＴＮＦ水平高于大肠杆菌０１１１∶Ｂ４脂多糖组（Ｐ＜０．０５）；而两倍剂量（５０００μｇ·ｋｇ－１·ｄ－１）的米糠脂多糖组的ＴＮＦ水平更高（Ｐ＜０．０５）；米糠脂多糖的经口ＬＤ５０＞５ｇ／ｋｇ。腹腔注射ＬＤ５０为０．３０±０．０３ｇ／ｋｇ，远低于大肠杆菌０１１１∶Ｂ４脂多糖的毒性。结论：米糠脂多糖是一种生物活性高且不具有大肠杆菌０１１１∶Ｂ４脂多糖高毒性的免疫增强剂。

IMMUNE FUNCTION ENHANCEMENT AND SAFETY EVALUATION OF LIPOPOLYSACCHARIDE FROM RICE BRAN

In this study, the effects of lipopolysaccharide from rice bran (LPS R) on the spleen index and the tumour necrosis factor (TNF) and the acute toxicity test were observed. Results: After one week of LPS injection (2500μg·kg -1 ·d -1 ) intraperitoneally, the spleen index in both LPS R and LPS E (LPS from Escherichia Coli 0111∶B4) groups was increased significantly. However, LPS R had more effect than LPS E in stimulating the reticuloendothelial system to secrete TNF. The TNF level was even higher when the LPS R dosage was doubled (5000μg·kg -1 ·d -1 ). The oral and intraperitoneal LD 50 of LPS R was over 5g/kg and 0.30± 0.03g/kg respectively,which are much lower than that of LPS E. Conclusion: The LPS R is an effective and safe immuno potentiator.