title: pH-sensitive microemulsion-based gels for removal of colonic ammonia: a novel preventative oral preparation for hepatic encephalopathy in rats.
abstract: Microemulsions with limited stability in mimetic gastrointestinal environments have previously demonstrated potential for the effective removal of ammonia from artificial colonic fluid. Specialized pH‑sensitive microemulsion‑based gels for the removal of colonic ammonia (MBG‑RCA), however, possess relative stability in the gastrointestinal (GI) tract of normal rats, indicating potential use in in vivo applications. An investigation of the effects of oral MBG‑RCA was conducted in order to evaluate the reduction of intestinal ammonia and the prevention of hepatic encephalopathy (HE) in rat models. Eighty rats were allocated into eight 4‑day treatment groups: The HE model (intraperitoneal injection of thioacetamide) group; the high‑, medium‑ and low‑dose MBG‑RCA therapeutic groups (15, 10 and 5 ml/kg MBG‑RCA, respectively); and the normal, blank, lactulose and acetic acid control groups, each of which received daily treatment administration. Oral MBG‑RCA effects were identified using behavioral monitoring observed by an infrared night vision supervisory control system, electroencephalograms, blood ammonia levels, intestinal ammonia levels, liver functionality and pathological observation. High‑ and medium‑dose oral administrations of MBG‑RCA significantly decreased the blood and intestinal ammonia levels (P<0.05), improved liver functionality and reduced the clinical manifestations of HE in rats. MBG‑RCA demonstrated high clearance of rat colonic ammonia while maintaining sufficient stability in the GI tract, indicating the potential for the development of new clinically relevant oral preparations for the prevention of HE. Additionally, such preparations are advantageous in that ammonia is eliminated without the production of potentially harmful metabolic byproducts.
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China.
authors.forename: Chun-Le
authors.initials: CL
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China.
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Duan
authors.affiliation: Pharmaceutical College, Dalian Medical University, Dalian, Liaoning 116044, P.R. China.
authors.forename: Ge
authors.initials: G
authors.lastname: Tian
authors.affiliation: Pharmaceutical College, Dalian Medical University, Dalian, Liaoning 116044, P.R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Membrane Science and Technology Center, Dalian University of Technology, Dalian, Liaoning 116012, P.R. China.
authors.forename: Gao-Hong
authors.initials: GH
authors.lastname: He
authors.affiliation: Membrane Science and Technology Center, Dalian University of Technology, Dalian, Liaoning 116012, P.R. China.
authors.forename: Teng-Fei
authors.initials: TF
authors.lastname: Bian
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China.
authors.forename: Xue
authors.initials: X
authors.lastname: Jin
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China.
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Sun
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Neurosurgery, Zhongshan Affiliated Hospital of Dalian University, Dalian, Liaoning 116001, P.R. China.
authors.forename: Qing-Yong
authors.initials: QY
authors.lastname: Chang
mesh_terms: D000410:Alanine Transaminase / Q000378:metabolism; D000641:Ammonia / Q000009:adverse effects* / Q000097:blood / Q000378:metabolism*; D000818:Animals; D001663:Bilirubin / Q000378:metabolism; D001835:Body Weight; D004195:Disease Models, Animal; D004569:Electroencephalography; D004655:Emulsions / Q000008:administration & dosage*; D005782:Gels; D006501:Hepatic Encephalopathy / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality / Q000628:therapy*; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000378:metabolism; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008297:Male; D051381:Rats; D012890:Sleep
chemical_list: D004655:Emulsions; D005782:Gels; D000641:Ammonia; D000410:Alanine Transaminase; D001663:Bilirubin