Laboratory of Proteins and Carbohydrates of Marine Algae, Department of Biochemistry and Molecular Biology - Federal University of Ceará. Fortaleza, Ceará, Brazil.
Laboratory of Proteins and Carbohydrates of Marine Algae, Department of Biochemistry and Molecular Biology - Federal University of Ceará. Fortaleza, Ceará, Brazil.
J Ethnopharmacol. 2018 Oct 5;224:27-35. doi: 10.1016/j.jep.2018.05.033. Epub 2018 May 25.
The use of marine seaweeds as a source of natural compounds with medicinal purposes is increasing in Western countries in the last decades, becoming an important alternative in the traditional medicine of many developing countries, where diarrhea still remains a severe public health problem, with high rates of mortality and morbidity. Sulfated polysaccharides (PLS) extracted from red seaweeds can exhibit therapeutic effects for the treatment of gastrointestinal disorders. Thus, the pharmacological properties of the PLS from Gracilaria cervicornis, an endemic seaweed found in the Brazilian northeast coast, was evaluated as an alternative natural medication for diarrhea.
This study aimed to evaluate the antidiarrheal activity of sulfated polysaccharides (PLS) extracted from the red seaweed G. cervicornis in Swiss mice pre-treated with castor oil or cholera toxin.
The seaweed Gracilaria cervicornis was collected at Flecheiras beach (city of Trairí, State of Ceará, Brazil) and the PLS was obtained through enzymatic extraction and administered in mice (25-30 g) before diarrhea induction with castor oil or cholera toxin. For the evaluation of the total number of fecal output and diarrheal feces, the animals were placed in cages lined with adsorbent material. The evaluation of intestinal fluid accumulation (enteropooling) on castor oil-induced diarrhea in mice occurred by dissecting the small intestine and measuring its volume. The determination of Na/K-ATPase activity was measured in the small intestine supernatants by colorimetry, using commercial biochemistry kits. The gastrointestinal motility was evaluated utilizing an activated charcoal as a food tracer. The intestinal fluid secretion and chloride ion concentration were evaluated in intestinal closed loops in mice with cholera toxin-induced secretory diarrhea. The binding ability of PLS with GM1 and/or cholera toxin was evaluated by an Enzyme-Linked Immunosorbent Assay (ELISA).
The G. cervicornis PLS showed antidiarrheal effects in both acute and secretory diarrhea, reducing the total number of fecal output, diarrheic stools, intestinal fluid accumulation, and increasing small intestine Na/K-ATPase activity on castor oil-induced diarrhea. However, the PLS did not affect gastrointestinal motility, indicating that this compound has a different action mechanism than loperamide. In secretory diarrhea, the PLS decreased intestinal fluid secretion and small intestine chloride excretion, binding with GM1 and/or cholera toxin and blocking their attachment to the enterocyte cell surface.
In conclusion, PLS has a significant antidiarrheal effect in acute and secretory diarrhea. Further investigation is needed towards its use as a natural medicine to treat diarrhea.
在过去几十年中，西方国家越来越多地将海洋海藻用作具有药用目的的天然化合物的来源，成为许多发展中国家传统医学的重要替代品，在这些国家，腹泻仍然是一个严重的公共卫生问题，死亡率和发病率都很高。从红海藻中提取的硫酸多糖（PLS）可以治疗胃肠道疾病。因此，评估了来自巴西东北部海岸特有的海藻鸡冠菜胶的 PLS 作为治疗腹泻的替代天然药物的药理学特性。
本研究旨在评估从红海藻鸡冠菜胶中提取的硫酸多糖（PLS）对预先用蓖麻油或霍乱毒素处理的瑞士小鼠的抗腹泻活性。
收集来自特赖里市弗莱切拉斯海滩（塞阿拉州）的红海藻鸡冠菜胶，并通过酶提取获得 PLS，然后在蓖麻油或霍乱毒素诱导腹泻前给小鼠（25-30g）给药。为了评估粪便总数和腹泻粪便，将动物放置在衬有吸附材料的笼子中。通过解剖小肠并测量其体积来评估蓖麻油诱导的腹泻小鼠的肠液积聚（肠液池）。通过比色法使用商业生化试剂盒在小肠上清液中测定 Na/K-ATPase 活性。利用活性炭作为食物示踪剂评估胃肠动力。在霍乱毒素诱导的分泌性腹泻的小鼠中，通过肠闭合环评估肠液分泌和氯离子浓度。通过酶联免疫吸附测定（ELISA）评估 PLS 与 GM1 和/或霍乱毒素的结合能力。
鸡冠菜胶 PLS 在急性和分泌性腹泻中均表现出抗腹泻作用，减少蓖麻油诱导的腹泻时粪便总数、腹泻粪便、肠液积聚，并增加小肠 Na/K-ATPase 活性。然而，PLS 不影响胃肠动力，表明该化合物的作用机制与洛哌丁胺不同。在分泌性腹泻中，PLS 减少肠液分泌和小肠氯离子排泄，与 GM1 和/或霍乱毒素结合并阻断其附着在肠细胞表面。
总之，PLS 对急性和分泌性腹泻有显著的抗腹泻作用。需要进一步研究将其用作治疗腹泻的天然药物。
