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Diethanolamine-modified pectin based core-shell composites as dual working gastroretentive drug-cargo

Bera H, Kumar S

Int J Biol Macromol, 2018 Mar;108:1053-1062.
PMID: 29122714 DOI: 10.1016/j.ijbiomac.2017.11.019

The current study aimed at developing diethonolamine-modified high-methoxyl pectin (DMP)-alginate (ALG) based core-shell composites for controlled intragastric delivery of metformin HCl (MFM) by combined approach of floating and bioadhesion. DMP with degree of amidation of 48.72% was initially accomplished and characterized by FTIR, DSC and XRD analyses. MFM-loaded core matrices were then fabricated by ionotropic gelation technique employing zinc acetate as cross-linker. The core matrices were further coated by fenugreek gum (FG)-ALG gel membrane via diffusion-controlled interfacial complexation method. Various formulations demonstrated excellent drug encapsulation efficiency (DEE, 51-70%) and sustained drug eluting behavior (Q8h, 72-96%), which were extremely influenced by polymer-blend (ALG:DMP) ratios, low density additives (olive oil/magnesium stearate) and FG-ALG coating inclusion. The drug release profile of the core-shell matrices (F-7) was best fitted in zero-order kinetic model with case-II transport driven mechanism. It also portrayed outstanding gastroretentive characteristics. Moreover, the composites were analyzed for surface morphology, drug-excipients compatibility, thermal behavior and drug crystallinity. Thus, the developed composites are appropriate for controlled stomach-specific delivery of MFM for type 2 diabetes management.

Matched MeSH terms: Stomach/metabolism*
Fulltext Culturable bacterial microbiota of the stomach of Helicobacter pylori positive and negative gastric disease patients

Khosravi Y, Dieye Y, Poh BH, Ng CG, Loke MF, Goh KL, et al.

ScientificWorldJournal, 2014;2014:610421.
PMID: 25105162 DOI: 10.1155/2014/610421

Human stomach is the only known natural habitat of Helicobacter pylori (Hp), a major bacterial pathogen that causes different gastroduodenal diseases. Despite this, the impact of Hp on the diversity and the composition of the gastric microbiota has been poorly studied. In this study, we have analyzed the culturable gastric microbiota of 215 Malaysian patients, including 131 Hp positive and 84 Hp negative individuals that were affected by different gastric diseases. Non-Hp bacteria isolated from biopsy samples were identified by matrix assisted laser desorption ionization-time of flight mass spectrometry based biotyping and 16SrRNA sequencing. The presence of Hp did not significantly modify the diversity of the gastric microbiota. However, correlation was observed between the isolation of Streptococci and peptic ulcer disease. In addition, as a first report, Burkholderia pseudomallei was also isolated from the gastric samples of the local population. This study suggested that there may be geographical variations in the diversity of the human gastric microbiome. Geographically linked diversity in the gastric microbiome and possible interactions between Hp and other bacterial species from stomach microbiota in pathogenesis are proposed for further investigations.

Matched MeSH terms: Stomach/metabolism*
Alterations in mucin type: an indicator for suspicion of malignant gastric transformation

Cheah PL, Ramachandran K

Malays J Pathol, 1994 Jun;16(1):39-42.
PMID: 16329574

Mucins are produced by both benign and malignant gastric epithelium. In general, mucins can be classified into neutral and acidic mucins. The latter are of 2 major types, sulphated (sulphomucins) and carboxylated (sialomucins). A retrospective study was initiated at the Department of Pathology, University Hospital, Kuala Lumpur to histochemically study the mucin profiles of cases of intestinal (IGC) and diffuse (DGC) types of gastric carcinoma in Malaysian patients to determine whether a significant change of mucin type occurs in the event of malignant transformation. 42 IGC and 37 DGC were subjected to alcian blue-periodic acid Schiff and high iron diamine-alcian blue histochemical staining. In addition, 18 cases of gastrectomies performed for benign lesions in the stomach served as normal controls. The number of cases of IGC and DGC which exhibited sulphomucin production was significantly increased (p < 0.001) compared to normal controls. Also, the number of cases of DGC which produced neutral mucin were significantly less (p < 0.05) than the control group. However, there was no significant difference between the number of IGC and DGC cases which demonstrated sialomucin production and normal controls. It appears that while not pathognomonic, a lack of neutral mucin production should alert the pathologist to the possibility of a gastric malignancy, in particular DGC. The likelihood of a malignant lesion would be further supported if there is an increased sulphomucin production.

Matched MeSH terms: Stomach/metabolism
Fulltext Tocotrienol and alpha-tocopherol reduce corticosterone and noradrenalin levels in rats exposed to restraint stress

Nur Azlina MF, Nafeeza MI

Pharmazie, 2008 Dec;63(12):890-2.
PMID: 19177905

This study investigates the effects of tocotrienol (TT) or alpha-tocopherol (TF) supplementation on corticosterone level, noradrenalin level and gastric lesions in rats exposed to restraint stress. Twenty-four male Sprague Dawley rats were randomly assigned into 4 equally sized groups; two control groups were given olive oil, while the treated group was supplemented with either tocotrienol of tocopherol orally at a dose of 60 mg/kg body weight. After 28 days of treatment, one control group, TT group and TF group were subjected to restraint stress, 2 hours daily for 4 consecutive days. After the last exposure to stress, plasma samples were taken to determine the corticosterone and noradrenalin levels, after which the rats were sacrificed. The stomach was excised for the evaluation of gastric lesions. Our findings showed that TT and TF were able to maintain the corticosterone level to the prestress values, while only TT was able to maintain the noradrenalin level in rats exposed to stress. Tocotrienol was found to be better in preventing formation of gastric lesions compared to TF. As a conclusion, the protective effect of vitamin E was related to the ability to inhibit stress induced elevation of corticosterone and noradrenalin levels.

Matched MeSH terms: Stomach/metabolism
Efficient Colonic Delivery of DsiRNA by Pectin-Coated Polyelectrolyte Complex Nanoparticles: Preparation, Characterization and Improved Gastric Survivability

Hussain Z, Katas H, Yan SL, Jamaludin D

Curr Drug Deliv, 2017;14(7):1016-1027.
PMID: 28240178 DOI: 10.2174/1567201814666170224142446

BACKGROUND: Despite having excellent anticancer efficacy and ability to knockdown gene expression, the therapeutic feasibility of Dicer-substrate small interfering RNA (DsiRNA) is limited due to its poor cellular uptake, chemical instability and rapid degradation in biological environments.
OBJECTIVE: The present study was aimed to circumvent the pharmaceutical issues related to DsiRNA delivery to colon for the treatment of colorectal cancer.
METHOD: In this study, we have prepared water-soluble chitosan (WSC)-DsiRNA complex nanoparticles (NPs) by a simple complexation method and subsequently coated with pectin to protect DsiRNA from gastric milieu.
RESULTS: The mean particle size and zeta potential of the prepared WSC-DsiRNA complexes were varied from 145 ± 4 nm to 867 ± 81 nm and +38 ± 4 to -6.2 ± 2.7 mV respectively, when the concentrations of WSC (0.1%, 0.2% and 0.3% w/v) and pectin (0.1%, 0.2% and 0.25% w/v) were varied. The electron microscopic analysis revealed that morphology of WSC-DsiRNA complexes was varied from smooth spherical to irregular spherical. Cytotoxicity analysis demonstrated that viability of colorectal adenocarcinoma cell was decreased when the dose of WSC-DsiRNA was increased over the incubation from 24 to 48 h. A significantly low cumulative release of DsiRNA in simulated gastric (<15%) and intestinal fluids (<30%) and a marked increase in its release (>90%) in simulated colonic fluid (SCF) evidenced the feasibility and suitability of WSC-DsiRNA complexes for the colonic delivery.
CONCLUSION: These findings clearly indicated promising potential of WSC-DsiRNA complexes as a carrier to delivery DsiRNA to colon for the treatment of colorectal cancer.

Matched MeSH terms: Stomach/metabolism
Fulltext Palm vitamin E reduces catecholamines, xanthine oxidase activity and gastric lesions in rats exposed to water-immersion restraint stress

Mohd Fahami NA, Ibrahim IA, Kamisah Y, Mohd Ismail N

BMC Gastroenterol, 2012;12:54.
PMID: 22639913 DOI: 10.1186/1471-230X-12-54

This study examined the effects of Palm vitamin E (PVE) and α-tocopherol (α-TF) supplementations on adrenalin, noradrenalin, xanthine oxidase plus dehydrogenase (XO + XD) activities and gastric lesions in rats exposed to water-immersion restraint stress (WIRS).

Matched MeSH terms: Stomach/metabolism
Stomach specific polymeric low density microballoons as a vector for extended delivery of rabeprazole and amoxicillin for treatment of peptic ulcer

Choudhary S, Jain A, Amin MCIM, Mishra V, Agrawal GP, Kesharwani P

Colloids Surf B Biointerfaces, 2016 May 01;141:268-277.
PMID: 26859118 DOI: 10.1016/j.colsurfb.2016.01.048

The study was intended to develop a new intra-gastric floating in situ microballoons system for controlled delivery of rabeprazole sodium and amoxicillin trihydrate for the treatment of peptic ulcer disease. Eudragit S-100 and hydroxypropyl methyl cellulose based low density microballoons systems were fabricated by employing varying concentrations of Eudragit S-100 and hydroxypropyl methyl cellulose, to which varying concentrations of drug was added, and formulated by stirring at various speed and time to optimize the process and formulation variable. The formulation variables like concentration and ratio of polymers significantly affected the in vitro drug release from the prepared floating device. The validation of the gastro-retentive potential of the prepared microballoons was carried out in rabbits by orally administration of microballoons formulation containing radio opaque material. The developed formulations showed improved buoyancy and lower ulcer index as compared to that seen with plain drugs. Ulcer protective efficacies were confirmed in ulcer-bearing mouse model. In conclusion, greater compatibility, higher gastro-retention and higher anti-ulcer activity of the presently fabricated formulations to improve potential of formulation for redefining ulcer treatment are presented here. These learning exposed a targeted and sustained drug delivery potential of prepared microballoons in gastric region for ulcer therapeutic intervention as corroborated by in vitro and in vivo findings and, thus, deserves further attention for improved ulcer treatment.

Matched MeSH terms: Stomach/metabolism*
Fulltext Anti-inflammatory, gastroprotective and anti-ulcerogenic effects of red algae Gracilaria changii (Gracilariales, Rhodophyta) extract

Shu MH, Appleton D, Zandi K, AbuBakar S

BMC Complement Altern Med, 2013;13:61.
PMID: 23497105 DOI: 10.1186/1472-6882-13-61

Gracilaria changii (Xia et Abbott) Abbott, Zhang et Xia, a red algae commonly found in the coastal areas of Malaysia is traditionally used for foods and for the treatment of various ailments including inflammation and gastric ailments. The aim of the study was to investigate anti-inflammatory, gastroprotective and anti-ulcerogenic activities of a mass spectrometry standardized methanolic extract of Gracilaria changii.

Matched MeSH terms: Stomach/metabolism