Pusztai A, Grant G, Buchan W C, Bardocz S, de Carvalho A F, Ewen S W
Rowett Research Institute, Bucksburn, Aberdeen, UK.
Br J Nutr. 1998 Feb;79(2):213-21. doi: 10.1079/bjn19980033.
The effects of inclusion of different levels of raw kidney bean (Phaseolus vulgaris) of high lectin content (27 g/kg meal) in a high-quality (lactalbumin) control diet were tested in nutritional trials on the growth and metabolism of obese Zucker (fafa) rats and their lean littermates in comparison with pair-fed controls. All diets contained 100 g total protein/kg and either 50 g lipids/kg (low fat) or 150 g lipids/kg (moderate fat). The growth of both obese and lean rats on bean diets was retarded by the daily bean intake in a dose-dependent manner. However, most of this was because bean-fed rats contained less body fat than the controls after 10 d. Thus, after feeding low-fat diets containing up to 130 g kidney bean/kg (lectin intake < or = 0.2 g/kg body weight (BW) per d) in both 10 d and 70 d trials, the bodies of obese rats contained less fat but not protein than their pair-fed controls. Moreover, by increasing the lipid content of the diet to 150 g/kg, the level of bean inclusion could be increased to 280 g/kg (lectin intake > or = 0.4 g/kg BW per d) without loss of body protein and skeletal muscle. Although these rats contained more body fat than those which were fed on low-fat diets, their weight reduction could be accounted for exclusively by reduced lipid content. In contrast, significant body protein loss occurred when the same diet of high lectin content was fed to lean littermates. Plasma insulin levels were significantly depressed in the obese Zucker rats on bean diets but the pancreas was not significantly enlarged nor its insulin content changed in 10 d trials. However, significant pancreatic growth occurred on long-term (70 d) bean feeding compared with pair-fed controls. The results suggest that, in addition to animal nutrition, it may also be possible to use the bean lectin as a dietary adjunct or therapeutic agent to stimulate gut function and ameliorate obesity if a safe and effective dose-range can be established for human subjects.
在肥胖的Zucker（fafa）大鼠及其瘦的同窝仔鼠的生长和代谢营养试验中，测试了在高质量（乳白蛋白）对照日粮中添加不同水平高凝集素含量（27克/千克日粮）的生芸豆（菜豆）的效果，并与配对饲喂的对照组进行比较。所有日粮每千克均含100克总蛋白，且要么含50克脂质/千克（低脂），要么含150克脂质/千克（中度脂肪）。日粮中添加芸豆后，肥胖和瘦大鼠的生长均以剂量依赖方式受到每日芸豆摄入量的抑制。然而，这主要是因为喂食芸豆的大鼠在10天后体脂比对照组少。因此，在10天和70天的试验中，给肥胖大鼠喂食含高达130克芸豆/千克（凝集素摄入量≤0.2克/千克体重（BW）/天）的低脂日粮后，其体内脂肪比配对饲喂的对照组少，但蛋白质含量并未减少。此外，通过将日粮中的脂质含量提高到150克/千克，芸豆添加水平可提高到280克/千克（凝集素摄入量≥0.4克/千克BW/天），而不会损失身体蛋白质和骨骼肌。虽然这些大鼠的体脂比喂食低脂日粮的大鼠多，但其体重减轻完全是由于脂质含量降低。相比之下，给瘦的同窝仔鼠喂食相同高凝集素含量的日粮时，会出现明显的身体蛋白质损失。喂食芸豆日粮的肥胖Zucker大鼠血浆胰岛素水平显著降低，但在10天试验中，胰腺并未显著肿大，其胰岛素含量也未改变。然而，与配对饲喂的对照组相比，长期（70天）喂食芸豆会使胰腺显著生长。结果表明，除了用于动物营养外，如果能为人类受试者确定一个安全有效的剂量范围，或许还可以将芸豆凝集素用作饮食辅助剂或治疗剂来刺激肠道功能并改善肥胖状况。
