Mynott T L, Guandalini S, Raimondi F, Fasano A
Department of Medicine, Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, USA.
Gastroenterology. 1997 Jul;113(1):175-84. doi: 10.1016/s0016-5085(97)70093-3.
BACKGROUND & AIMS: Diarrhea is a major cause of illness and death in children and young animals. The aim of this study was to investigate the possible therapeutic effect of bromelain, a proteolytic extract obtained from pineapple stems on bacterial toxin and second-messenger agonist-induced intestinal secretion.
The effect of bromelain pretreatment on short-circuit responses to Escherichia coli heat-labile enterotoxin, heat-stable enterotoxin, and Vibrio cholerae cholera toxin was evaluated in rabbit ileum mounted in Ussing chambers.
Bromelain was 62% effective in preventing heat-labile enterotoxin-induced secretion, 51% effective against cholera toxin, and 35% effective against heat-stable enterotoxin [corrected]. Bromelain also prevented secretory changes caused by prostaglandin E2, theophylline, calcium-ionophore A23187, 8-bromoadenosine 3':5'-cyclic monophosphate, and 8-bromoguanosine 3':5'-cyclic monophosphate, well-known intracellular mediators of ion secretion. The efficacy of bromelain was not caused by reduced tissue viability resulting from its proteolytic effects on enterocytes, indicated by experiments measuring uptakes of nutrients into intestinal cells and experiments measuring short-circuit responses to glucose.
Bromelain prevents intestinal fluid secretion mediated by secretagogues that act via adenosine 3':5'-cyclic monophosphate, guanosine 3':5'-cyclic monophosphate, and calcium-dependent signaling cascades. It may be clinically useful as an antidiarrheal drug.
腹泻是儿童和幼龄动物患病和死亡的主要原因。本研究旨在探讨菠萝蛋白酶（一种从菠萝茎中提取的蛋白水解提取物）对细菌毒素和第二信使激动剂诱导的肠道分泌的可能治疗作用。
在安装于尤斯灌流小室的兔回肠中，评估菠萝蛋白酶预处理对大肠杆菌不耐热肠毒素、耐热肠毒素及霍乱弧菌霍乱毒素引起的短路电流反应的影响。
菠萝蛋白酶对预防不耐热肠毒素诱导的分泌有效率为62%，对霍乱毒素有效率为51%，对耐热肠毒素有效率为35%[校正后]。菠萝蛋白酶还可预防由前列腺素E2、茶碱、钙离子载体A23187、8-溴腺苷3':5'-环磷酸单酯和8-溴鸟苷3':5'-环磷酸单酯引起的分泌变化，这些都是众所周知的离子分泌细胞内介质。通过测量营养物质进入肠细胞的摄取实验以及测量对葡萄糖的短路电流反应实验表明，菠萝蛋白酶的疗效并非因其对肠上皮细胞的蛋白水解作用导致组织活力降低所致。
菠萝蛋白酶可预防由通过腺苷3':5'-环磷酸单酯、鸟苷3':5'-环磷酸单酯和钙依赖性信号级联起作用的促分泌剂介导的肠液分泌。它可能作为一种抗腹泻药物具有临床应用价值。
