Takeshita M, Nakamura S, Makita F, Ohwada S, Miyamoto Y, Morishita Y
Second Department of Surgery, School of Medicine, Gunma University, Japan.
Biotherapy. 1992;4(2):139-45. doi: 10.1007/BF02171758.
We examined whether orally administered RBS (rice bran saccharide), prepared from rice bran by hot water extraction, increases immunocompetence, inhibits gastrointestinal carcinogenesis with N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) or shows an antitumor effect. After the administration of RBS, phytohemagglutinin (PHA)- and pokeweed mitogen (PWM)-stimulated blastogenesis of lymphocytes derived from the mesenteric lymph nodes and peripheral blood was enhanced, and the helper/suppressor T-cell ratio was elevated, and migration activity of peritoneal macrophages was also increased in rats treated continuously with ENNG. ENNG-induced gastrointestinal carcinomas were observed in 43% of those administered RBS (ENNG-RBS) as compared with 88% in the control (ENNG) and 94% in the prednisolone (PRD) group (ENNG-PRD). The 12-month survival rate of rats bearing gastrointestinal cancer was 58% in the ENNG-RBS group as compared with 25% in the ENNG group and 15% in the ENNG-PRD group. RBS prevented the reduction in immunocompetence in the course of carcinogenesis, suppressed carcinogenesis, and prolonged the survival of rats with gastrointestinal cancer. Antitumor activities of RBS are thought to be a kind of host mediated action. The growth inhibition ratio of transplantable ENNG-induced cancer in Wistar rats was 42.1% in the RBS and 51.8% in the 5-FU group. Since little is known about the potent antitumor activity of alpha-glucan, it would be interesting to consider the relationship between the structure and the biological activities of polysaccharides.
我们研究了通过热水提取从米糠制备的口服米糠糖（RBS）是否能增强免疫能力、抑制由N-乙基-N'-硝基-N-亚硝基胍（ENNG）诱导的胃肠道癌变或显示出抗肿瘤作用。给予RBS后，在连续用ENNG处理的大鼠中，源自肠系膜淋巴结和外周血的淋巴细胞经植物血凝素（PHA）和商陆有丝分裂原（PWM）刺激后的细胞增殖增强，辅助/抑制性T细胞比例升高，腹膜巨噬细胞的迁移活性也增加。给予RBS的大鼠（ENNG-RBS）中观察到ENNG诱导的胃肠道癌的发生率为43%，而对照组（ENNG）为88%，泼尼松龙（PRD）组（ENNG-PRD）为94%。患有胃肠道癌的大鼠的12个月生存率在ENNG-RBS组中为58%，而在ENNG组中为25%，在ENNG-PRD组中为15%。RBS可防止癌变过程中免疫能力的降低，抑制癌变，并延长患有胃肠道癌的大鼠的生存期。RBS的抗肿瘤活性被认为是一种宿主介导的作用。在Wistar大鼠中，可移植的ENNG诱导癌的生长抑制率在RBS组中为42.1%，在5-氟尿嘧啶组中为51.8%。由于对α-葡聚糖的强效抗肿瘤活性了解甚少，考虑多糖的结构与生物活性之间的关系将是很有趣的。
