Colonic Enzymes Research Articles

Modulation of mesalamine release from enteric-coated matrix tablets using natural polysaccharides for localized colonic delivery

Background: Inflammatory bowel diseases (IBD) require effective colon-targeted drug delivery for improved therapeutic efficacy and minimized systemic side effects. Objectives: The objective of this research was to develop and evaluate novel colon-targeted matrix tablet formulations of mesalamine (5-aminosalicylic acid) for the treatment of IBD. Materials and Methods: Mesalamine matrix tablets were prepared by wet granulation technique using pH-sensitive polymers (HPMC K4M) and biodegradable natural polysaccharides (pectin, chitosan, and guar gum). Tablets were characterized for physicochemical properties, drug content, and in vitro drug release. Compatibility studies using FTIR and DSC confirmed no interaction between mesalamine and polymers. The optimized formulations were enteric-coated with Eudragit S100 and ethyl cellulose. Drug release kinetics and stability studies were conducted. Results and Discussion: The uncoated formulations (M3, M6, M7) showed adequate protection against drug release in simulated gastric (0-2 h) and intestinal (2-5 h) fluids. The enteric-coated formulations (ME3, ME6, ME7) exhibited a lag time of around 2 hours and restricted drug release (<5%) in simulated gastric and intestinal fluids up to 5 hours. However, in simulated colonic fluid (pH 6.8) containing 4% rat cecal contents, these formulations showed enhanced drug release (71-83% in 12 h) due to biodegradation of polymeric matrices by colonic enzymes. Drug release kinetics indicated anomalous transport or super case-II transport mechanisms. Stability studies at 40°C/75% RH for 3 months revealed no significant changes. Conclusion: The developed colon-targeted mesalamine matrix tablets demonstrated the potential to protect the drug from release in the upper GIT while facilitating targeted drug delivery to the colon, which could improve therapeutic efficacy and minimize systemic side effects in the treatment of IBD.

A REVIEW ON DEVELOPMENT OF COLON TARGETED DRUG DELIVERY SYSTEM

The purpose of this review was to select a promising drug delivery system for colon diseases. This review covers the development of Colon Targeted Drug Delivery System (CTDDS) using 36 y (1986-2022) data from various research and review articles. All fig. designed using by BioRender website. vThe colon-targeted drug delivery systems developed for the specific site drug delivery which applied for both local and systemic actions of the drug; since the drug targeted to be release within the colon, the unwanted systemic side effects are reduced along with it. Systemic side effects include organ damage, respiratory diseases and, cardiovascular damage and other illnesses. Colon-targeted drug delivery system used in the treatment of diseases in the colon, including ulcerative colitis, irritable bowel syndrome and colorectal cancer. The benefit of colon-targeted drug delivery besides the reduction of side effects also include protection from premature drug release or burst in the stomach or small intestine before reaching the colon. For the development of drugs with such benefits and advantages, drug delivery systems and approaches have used for Colon targeted drug delivery systems, varying from conventional colon-targeting drug delivery systems to novel approaches for Colon-targeted drug delivery systems. Conventional drug delivery includes the use of prodrugs, pH-dependent, time-dependent, matrix-based systems, polysaccharides-derived systems, and bio-adhesive system while novel approaches include types such as port system, pulsincap system, pressure-controlled system, osmotic controlled system, CODES, and the newest approach wish is the use of nanotechnology in colon targeted drug delivery. In this research both techniques reviewed, and their types discussed as well. The limitation of their uses and the advantage of each system discussed with a breakdown of the different mechanisms used to formulate such systems. A successful colon targeting delivery can release the drug to a specific segment in colon due to presence of different colonic enzymes formed by microorganisms that metabolize drug carrier linkage. Use of combined approaches i.e., conventional systems and newer approaches may be the best way to cure colon diseases using an optimized colon drug delivery system.

Oral delivery of pectin-chitosan hydrogels entrapping macrophage-targeted curcumin-loaded liposomes for the treatment of ulcerative colitis

The oral delivery of anti-inflammatory drugs has been a promising strategy for enhancing the clinical efficacy of ulcerative colitis (UC) treatment strategies. However, achieving site specific drug delivery to colon tissues and target cells is a challenging task for formulation scientists. In this study, macrophages-targeted liposome-loaded pectin-chitosan hydrogels were developed for UC treatment via oral administration. Folate-functionalized cholesterol was synthesized as lipid membrane materials for the liposomes containing curcumin (CUR). The incorporation of the liposomal CUR within pectin-chitosan hydrogels resulted in a matrix that exhibited considerable sensitivity to colonic enzymes during in vitro release. The targeted delivery of hybrids was able to effectively reach macrophages. They also showed enhanced capability to downregulate TNF-α, IL-6, and IL-1β in the lipopolysaccharide-induced Raw 264.7 cells model. DSS-induced mice modelshowed improved anti-UC effects, including accelerated mucosal repair and decreased inflammation and modulate the immune balance in the intestinal tissue of mice with colitis, which may be attributable to increased drug accumulation in the colonic lumen and improved internalization to target cells. Therefore, the incorporation of folate-modified liposomes containing CUR and pectin-chitosan physical hydrogels could potentially serve as a favorable approach for treating UC through an oral colon-targeted drug delivery system.

Evaluation of Ethanolic leaf extract of Cucumis melo var. agrestis in Acetic Acid-Induced Ulcerative Colitis on Rats

The crux of the present research work was to evaluate the therapeutic potential of Ethanolic leaf extract of Cucumis melo var. agrestis (ELECM)on Ulcerative Colitis in rats. The successful induction of Ulcerative Colitis was done by intra-rectal administration of 500 μl of acetic acid (4% v/v), rats were euthanized on day 8 by cervical dislocation under anesthesia. The pathological parameters such as colon weight, colon antioxidant enzymes (SOD, CAT), lipid peroxidase enzymes (MDA, MPO), inflammatory markers (TNF- α and IL-6), and histopathological aspects were estimated to evaluate the ELECM against the disease control. Sulfasalazine was used as positive control to compare the protective effect of the ELECM. The GC-MS analysis of ELECM confirms the presence of about 12 specific phytochemicals. Induction of ulcerative colitis was evidenced in the control group due to increased colon weight, lipid peroxidase enzymes, and immune markers also by alleviated levels of antioxidant enzymes in the rat colon. However, ELECM treated group almost reversed the effect of the disease control group, above all the histopathological response of the ELECM-treated group against the acetic acid-induced ulcerative colitis was almost the same as that of the control group, indicating the significant protective effect. Our present study suggests that ELECM extract has significant protective activity against acetic acid-induced ulcerative colitis, due to its higher antioxidant, moderate anti-inflammatory, and mild immune-suppressive effects, and the protective action might be due to the presence of active constituents such as flavonoids and total phenols as presented on the GC-MS analysis report.

Oral delivery of porous starch-loaded bilayer microgels for controlled drug delivery and treatment of ulcerative colitis

We prepared one type of bilayer microgels for oral administration with three effects: pH responsiveness, time lag, and colon enzyme degradation. Combined with the dual biological effects of curcumin (Cur) for reducing inflammation and promoting repair of colonic mucosal injury, targeted colonic localization and release of Cur according to the colonic microenvironment were enhanced. The inner core, derived from guar gum and low-methoxyl pectin, afforded colonic adhesion and degradation behavior; the outer layer, modified by alginate and chitosan via polyelectrolyte interaction, achieved colonic localization. The porous starch (PS)-mediated strong adsorption allowed Cur loading in inner core to achieve a multifunctional delivery system. In vitro, the formulations exhibited good bioresponses at different pH conditions, potentially delaying Cur release in the upper gastrointestinal tract. In vivo, dextran sulfate sodium-induced ulcerative colitis (UC) symptoms were significantly alleviated after oral administration, accompanied by reduced levels of inflammatory factors. The formulations facilitated colonic delivery, allowing Cur accumulation in colonic tissue. Moreover, the formulations could alter gut microbiota composition in mice. During Cur delivery, each formulation increased species richness, decreased pathogenic bacterial content, and afforded synergistic effects against UC. These PS-loaded bilayer microgels, exhibiting excellent biocompatibility, multi-bioresponsiveness, and colon targeting, could be beneficial in UC therapy, allowing development into a novel oral formulation.

Synthesis of carboxmethyl chitosan and its effect on budesonide colon sensitive nano release system

In this investigation, colon sensitive nanoparticles were prepared using different agents by ion-gelation method. The carboxymethyl chitosan nanoparticles (CMCH-NPs) were used to deliver budesonide to the colon. The formation of Carboxymethyl chitosan (CMCH) was confirmed by H1NMR, FTIR, and degree of substitution (Ds). CMCH-NPs were evaluated for drug excipient interaction, loading efficiency % (LE), entrapment efficiency % (EE), scanning electron microscopy (SEM), zeta potential, particle size distribution, in-vitro release studies (also with enzymes), cytotoxicity, and stability studies. In-vitro release studies by dialysis bag method without enzymes revealed that N4 and N6 showed less than 10% cumulative drug release (% CDR) in pH1.2. SEM results of N6 showed spherical shaped aggregates and smoother surfaces than N4. Consequently, the presence of pepsin in pH 1.2, diastase in pH 4.5 and pancreatin in pH 7.4 buffers did not have any significant effect on the release kinetics of the N6 CMCH-NPs. On addition of the colonic enzymes in 10th hour, there was a marked increase in the release of budesonide (upto 98.27% ± 1.30%) due to the action of enzymes produced by the colonic microflora which causes the lysis of glycosidic bonds. The evidence for pH sensitivity along with the microbiotic activation of the CMCH-NPs in the colon was thus established. The cell viability (%) in all samples was above 96%, ensuring the biocompatibility of CMCH in the dose range of 0.2–2.4 mg/mL. Stability studies as per ICH Q1A (R2) guidelines were found to be stable.

Development and In Vivo Evaluation of Pectin Based Enteric Coated Microparticles Loaded with Mesalamine and Saccharomyces boulardii for Management of Ulcerative Colitis.

Mesalamine is the first-line choice of drug for ulcerative colitis management. However, due to the nontargeted delivery of mesalamine, it shows side effects. The possible impact of mesalamine can be improved by coated microparticles in combination with S. boulardii for targeted delivery to the colon with the prevention of unwanted side effects. In this work, pectin-based mesalamine and S. boulardii loaded microparticles were prepared by dehydration technique and coated by an oil-in-oil solvent evaporation method and characterized by Scanning electron microscopy (SEM), X-ray diffraction, and zeta analysis. 2, 4, 6-Trinitrobenzenesulfonic acid was used for the induction of colitis. The anti-inflammatory effects of coated microparticles on Caco-2 cells were assessed by the determination of interleukin (IL)-8 concentration. In addition, the impact of coated microparticles on the concentration of colonic enzymes, including myeloperoxidase (MPO), lipid peroxides, and glutathione (GSH), were also evaluated. Moreover, hematological parameters, including white blood cell (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), were assessed. SEM data revealed that all the prepared coated microparticles had an almost spherical shape. The X-ray powder diffraction analysis of uncoated and coated microparticles showed maximum stability without any interaction. The particle size of uncoated and coated microparticles was 9.14 and 15.61 μm, respectively. The zeta potential of uncoated and coated microparticles was observed to be -26.78 and -29.36 mV, respectively. The prepared coated microparticles decreased the levels of lipid peroxides, MPO, and GSH significantly in colitis. In the Caco-2 cell culture model, the concentration of IL-8 is decreased significantly. The hematological observations confirmed that the prepared formulation showed a promising decrease in the levels of WBC, CRP, and ESR in diseased animals. Animal experiments revealed that cellulose acetate phthalate coated microparticles of mesalamine and S. boulardii significantly improved the colitis disease conditions of Wistar rats. Hence, cellulose acetate phthalate-coated microparticles of mesalamine and S. boulardii could be recommended as adjuvant therapy to achieve a synergistic effect in the management of UC. Lay summary Mesalamine is the drug of choice for the management of ulcerative colitis (UC), which inhibits mediators responsible for inflammation. We investigated the in vivo effects of cellulose acetate phthalate-coated microparticles of mesalamine with Saccharomyces boulardii (probiotic) for their efficacy against UC. Our findings evidenced that the combination of mesalamine with S. boulardii showed a synergistic effect in the 2,4,6- trinitrobenzene sulfonic acid-induced colitis model by reducing the inflammation and maintains the macroscopic features. From the observed results, it can be concluded that S. boulardii can be used to enhance the individual drug's effect in the therapeutic management of UC.

Response surface method for optimization of prepared satranidazole powder layered pellets

BackgroundThe purpose of the present study was to evaluate layered of satranidazole powder using natural polysaccharides as coating materials for colon targeting that were inexpensive and natural with a non-toxic nature using a composite response design of 3 levels and 2 factors for each of the four responses in the quadratic model. The independent variables were the ratio of coating consistency % (X1) and coating level % (X2) in the pellet. The dependent factors were % release of drug at 2 h. (Y1), % release of drug at 6 h. (Y2), % release of drug difference in presence & absence of colonic enzyme (Y3) and mean dissolution time (Y4). The various models were fitted for the responses with an explanation of suitable statistical methods. Variance analysis and different factor levels of responses were constructed by response surface plots.ResultsSatranidazole pellets were efficiently prepared by the variable amount of ingredients that showed compatibility with possible pellet characterization and drug dissolution profiles to optimize the formulation.ConclusionsThe strategy of response surface can be a successful tool for improving the prepared satranidazole pellets which can be an appropriate replacement of regular one.

Correlations between Low Doses of Zearalenone, Its Carryover Factor and Estrogen Receptor Expression in Different Segments of the Intestines in Pre-Pubertal Gilts-A Study Protocol.

Plant materials can be contaminated with Fusarium mycotoxins and their derivatives, whose toxic effects on humans and animals may remain subclinical. Zearalenone (ZEN), a low-molecular-weight compound, is produced by molds in crop plants as a secondary metabolite. The objective of this study will be to analyze the in vivo correlations between very low monotonic doses of ZEN (5, 10, and 15 μg ZEN/kg body weight—BW for 42 days) and the carryover of this mycotoxin and its selected metabolites from the intestinal contents to the intestinal walls, the mRNA expression of estrogen receptor alfa (ERα) and estrogen receptor beta (ERβ) genes, and the mRNA expression of genes modulating selected colon enzymes (CYP1A1 and GSTP1) in the intestinal mucosa of pre-pubertal gilts. An in vivo experiment will be performed on 60 clinically healthy animals with initial BW of 14.5 ± 2 kg. The gilts will be randomly divided into a control group (group C, n = 15) and three experimental groups (group ZEN5, group ZEN10, and group ZEN15; n = 15). Group ZEN5 will be administered per os 5 μg ZEN/kg BW (MABEL), group ZEN10—10 μg ZEN/kg BW (NOAEL), and group ZEN15—15 µg ZEN/kg BW (low LOAEL). In each group, five animals will be euthanized on analytical dates 1 (exposure day 7), 2 (exposure day 21), and 3 (exposure day 42). Samples for in vitro analyses will be collected from an intestinal segment resected from the following regions: the third (horizontal) part of the duodenum, jejunum, ileum, cecum, ascending colon, transverse colon, and descending colon. The experimental material will be collected under special conditions, and it will be transported to specialist laboratories where samples will be obtained for further analyses.

Abstract A40: Induction of oxidative/nitrosative stress, proinflammatory cytokines and dysregulation of Wnt/beta-catenin signaling by benzo(a)pyrene in colons of BALB/c mice

Abstract Epidemiologic surveys and experimental data have revealed that environmental and dietary factors contribute to the etiology of colon cancer, which ranks third in cancer-related mortalities in the United States and fourth worldwide. In particular, human diet containing environmental carcinogens such as benzo(a)pyrene (B(a)P), a polycyclic aromatic hydrocarbon, has been the focus of investigators recently in relation to generated interest in looking at how it exerts its colorectal cancer. The present study investigated the effects of B(a)P on biomarkers of oxidative stress, inflammation and Wnt-signaling in colon of BALB/c mice following exposure to varying doses of 62.5, 125, and 250 mg/kg B(a)P for 7 days by oral gavage. Exposure to B(a)P induced marked oxidative stress accompanied by decrease in the colonic antioxidant enzyme activities and glutathione level with concomitant increase in myeloperoxidase activity, nitric oxide, and lipid peroxidation levels. Colon histopathology results showed B(a)P-related lesions characterized by atrophy, mucosal ulceration, and gland erosion in the mice. Immunohistochemistry analysis showed that B(a)P treatment increased the protein expression of nuclear factor kappa B, proinflammatory cytokines, namely tumor necrosis factor alpha and interleukin-1 β, as well as cyclooxygenase-2 and inducible nitric oxide synthase in the mice colon. Altered canonical Wnt signaling was confirmed by strong diaminobenzidine staining for p38 mitogen-activated protein kinase, b-catenin expression, and absence of adenomatous polyposis coli following B(a)P administration. Overall, our results show that exposure of mice to B(a)P induces colonic toxicity by mechanism involving oxidative and nitrosative stress, inflammation, and dsyregulation of Wnt/b-catenin signaling, and emphasizes the role of environmental polycyclic aromatic hydrocarbons like B(a)P in the pathology of colonic toxicity and tumorigenesis. Citation Format: Ebenezer O. Farombi, Babajide O. Ajayi, Isaac A. Adedara, Solomon E. Owumi. Induction of oxidative/nitrosative stress, proinflammatory cytokines and dysregulation of Wnt/beta-catenin signaling by benzo(a)pyrene in colons of BALB/c mice [abstract]. In: Proceedings of the AACR Special Conference on Environmental Carcinogenesis: Potential Pathway to Cancer Prevention; 2019 Jun 22-24; Charlotte, NC. Philadelphia (PA): AACR; Can Prev Res 2020;13(7 Suppl): Abstract nr A40.

Spent coffee (Coffea arabica L.) grounds positively modulate indicators of colonic microbial activity

Spent coffee grounds (SCG; MR-medium and DR-dark-roasted) were submitted to an in vitro gastrointestinal digestion followed by a colonic fermentation using two microbiota communities (lean and overweight). The in vitro protective colonic effect of SCG was evaluated on colonic enzyme activities (β-glucosidase, β-glucuronidase, tryptophanase, and urease). The bioaccessibility of oligosaccharides and melanoidins, as well as colonic short-chain fatty acids (SCFAs) and ester production were determined and correlated with evaluated colonic enzymes. Melanoidins (8–17 mg/100 g) were highly correlated with antioxidant capacity (16–80 μmol Trolox/g sample; r = −0.78, p = 0.0001, ABTS), while raffinose was only detected during the colonic phase (1.22–4.23 mg/g) suggesting SCG use as human microbiota substrate. The extract obtained from MR-SCG colonic fermentation inhibited enzyme activity (up to 80%) at a rate similar to or even higher than inulin (used as a positive control during colonic fermentation). Using the same substrate (MR-SCG), microbial communities produced different amounts and SCFAs ester patterns, linked to the enzymatic inhibition effects. OW-microbiota produced the highest cumulative SCFAs (36 nmol/L; 55% more than L-microbiota). Molecular studies, and in vivo assays are needed to further elucidate the mechanisms exerted by SCG. Microbial communities need to be identified to determine the colonic effects of SCG and support their use as a functional food ingredient. Industrial relevanceOur results support the added value of this industrial by-product to be used as a nutraceutical or functional ingredient for food products. Reducing food losses and waste ‘is essential’ to improve the sustainability of food systems, and contribute to broader systemic changes, including nutrition and health. SCG are digested under in vitro human gastrointestinal condition, where nutraceutical compounds are released from the matrix exerting health benefits, including antioxidant capacity, and positively modulating indicators of colonic microbial activity.

Correlations between exposure to deoxynivalenol and zearalenone and the immunohistochemical expression of estrogen receptors in the intestinal epithelium and the mRNA expression of selected colonic enzymes in pre-pubertal gilts

Plant-based materials used in the production of pig feed are very often contaminated with deoxynivalenol and zearalenone. Daily intake of small amounts of these mycotoxins with feed induces various subclinical states in gilts and influences different biological processes. The aim of this preclinical study was to determine the correlation between monotonic doses of zearalenone and deoxynivalenol (40 μg/kg body weight and 12 μg/kg body weight, respectively, administered over a period of 42 days) and the immunohistochemical expression of estrogen receptors in the intestinal tract and the mRNA expression of selected colonic enzymes. The immunohistochemical expression of estrogen receptor alpha was observed in the colon, but its intensity varied in different weeks of exposure. A minor increase in estrogen receptor beta expression was noted only in the colon, whereas the expression of cytochrome P450 1A1 enzyme mRNA and mRNA isoform of the glutathione S-transferase π gene decreased. The observed correlations suggest that the risk of loss of control over the biotransformation and biological activity of the parent compounds in distal intestinal mucosa is delayed.

Guar gum modified upconversion nanocomposites for colorectal cancer treatment through enzyme-responsive drug release and NIR-triggered photodynamic therapy

Multimodal therapeutic approach towards colorectal cancer (CRC) holds great promise. There is, however, no convincing strategy reported to date that employs a multimodal strategy in CRC treatment. The present study reports an intense green-emitting core–shell photoluminescent upconversion (CSGU) nanocrystal engineered to synergistically perform photodynamic and enzyme-triggered delivery of the chemotherapeutic agent for an enhanced therapeutic outcome on HT-29 colon carcinoma cells in vitro. The photodynamic activity is achieved by the energy transfer between CSGU and the chemically conjugated Rose Bengal (RB) molecules that are further protected by a mesoporous silica (MS) layer. The chemical assay demonstrates a remarkable FRET mediated generation of 1O2 under NIR (980 nm) excitation. The outermost MS layer of the nanoplatform is utilized for the loading of the 5FU anticancer drug, which is further capped with a guar gum (GG) polysaccharide polymer. The release of the 5FU is specifically triggered by the degradation of the GG cap by specific enzymes secreted from colonic microflora, which otherwise showed ‘zero-release behavior’ in the absence of any enzymatic trigger in various simulated gastro-intestinal (GI) conditions. Furthermore, the enhanced therapeutic efficacy of the nanoplatform (CSGUR-MSGG/5FU) was evaluated through in vitro studies using HT-29 CRC cell lines by various biochemical and microscopic assays by the simultaneous triggering effect of colonic enzyme and 980 nm laser excitation. In addition, the strong visible emission from the nanoplatform has been utilized for NIR-induced cellular bioimaging.

The EBI2-oxysterol axis promotes the development of intestinal lymphoid structures and colitis

The gene encoding for Epstein-Barr virus-induced G-protein-coupled receptor 2 (EBI2) is a risk gene for inflammatory bowel disease (IBD). Together with its oxysterol ligand 7α,25-dihydroxycholesterol, EBI2 mediates migration and differentiation of immune cells. However, the role of EBI2 in the colonic immune system remains insufficiently studied. We found increased mRNA expression of EBI2 and oxysterol-synthesizing enzymes (CH25H, CYP7B1) in the inflamed colon of patients with ulcerative colitis and mice with acute or chronic dextran sulfate sodium (DSS) colitis. Accordingly, we detected elevated levels of 25-hydroxylated oxysterols, including 7α,25-dihydroxycholesterol in mice with acute colonic inflammation. Knockout of EBI2 or CH25H did not affect severity of DSS colitis; however, inflammation was decreased in male EBI2−/− mice in the IL-10 colitis model. The colonic immune system comprises mucosal lymphoid structures, which accumulate upon chronic inflammation in IL-10-deficient mice and in chronic DSS colitis. However, EBI2−/− mice formed significantly less colonic lymphoid structures at baseline and showed defects in inflammation-induced accumulation of lymphoid structures. In summary, we report induction of the EBI2-7α,25-dihydroxycholesterol axis in colitis and a role of EBI2 for the accumulation of lymphoid tissue during homeostasis and inflammation. These data implicate the EBI2-7α,25-dihydroxycholesterol axis in IBD pathogenesis.

Intestinal glucocorticoid synthesis enzymes in pediatric inflammatory bowel disease patients.

Inflammatory bowel disease (IBD), such as Crohn's disease and ulcerative colitis are devastating chronic immunopathologies of the intestinal mucosa, which are frequently treated by immunosuppressive glucocorticoids. Endogenous glucocorticoids are not only produced by the adrenal glands, but also by the intestinal epithelium. Local glucocorticoid synthesis critically contributes to the immune homeostasis of the intestinal mucosa. As defective intestinal glucocorticoid synthesis has been associated with the development of IBD, we investigated the expression of steroidogenic enzymes and the key transcriptional regulator Liver Receptor Homolog-1 (LRH-1/NR5A2) in ileal and colonic biopsies human pediatric IBD and control patients. Furthermore, the induction of steroidogenic enzymes and their transcriptional regulation by LRH-1 was investigated in a mouse model of experimental colitis. These analyses revealed that colitis-induced expression of steroidogenic enzymes in the murine colon is dependent on the presence of LRH-1, as intestinal deletion of LRH-1 strongly reduced their colitis-induced expression. Similarly, a strong correlation between the expression of LRH-1 and different steroidogenic enzymes was seen in intestinal biopsies of human pediatric patients. Importantly, reduced expression of hydroxysteroid dehydrogenase 11B1 (HSD11B1) was observed in IBD patients compared to control patients, suggesting that defective local reactivation of glucocorticoids could contribute to the pathogenesis of IBD.

Effect of polymer concentration and solution pH on viscosity affecting integrity of a polysaccharide coat of compression coated tablets

Tablets, compression coated with certain polysaccharides and intended for colon delivery, retain the integrity of the coat for an initial period of about 6 h (lag period) beyond which (post-lag period) the coat is degraded by colonic enzymes to induce drug release. This work was undertaken to investigate the factors which influence the integrity of the coat during the lag period. Core tablets containing two model drugs were compression coated with various amounts of carboxymethyl locust bean gum (CMLBG). In-vitro release of drugs, erosion of coat, and steady shear viscosity of CMLBG solutions having different concentrations and solution pH were determined. The viscosity of CMLBG that depended primarily on CMLBG concentration and partly on solution pH was responsible for erosion and integrity of the coat in the lag period. Evaluation of polymer viscosity could describe the integrity of coat of a polysaccharide coated tablet in the lag period.

Fabrication and Evaluations of Dual Crosslinked Mesalamine containing Pectin-Chitosan gel micro beads for controlled and targeted colon delivery

Objectives: The aim of the present work was to prepare and characterize mesalamine loaded microbeads (MLM) consisting of optimized ratios of chitosan and pectin polysaccharides using ionic gelation technique for management of inflammatory bowel disease. Methodology: Mesalamine loaded microbeads were prepared using ionotropic gelation method that was double cross linked with calcium chloride (3-6%, w/v) and sodium sulphate (2-4%, w/v) solutions. The formulation was optimized with the help of two levels and three factors factorial design method. The optimization parameters selected for formulation variables were viz., pectin-chitosan ratio, calcium chloride-sodium sulphate ratio and curing time. The prepared formulations were further characterized on the basis of particle size, shape, swelling index, entrapment efficiency, and percentage yield and in vitro drug release studies. The in vitro release studies using rat caecal content (2 and 4 % w/v) was also performed to simulate the human colonic condition. Results: The mean particle size, entrapment efficiency and percentage yield of MLM were ranged from 875.45 to 975.45 µm, 72.2 to 86.7% and 93.6 to 97.9% respectively. The swelling index of MLM formulations revealed lesser into acidic medium, while augmented swellings were found to be at pH 6.8 and 7.2 respectively. The swelling degree was found to be 7.34 to 13.88% into SIF at pH 6.8 whereas, intensely swelled was 16.24 to 46.02% into SCF at pH 7.2 during 8 h studies. In vitro drug release profile of MLM exhibited that only 1.28 to 4.42 drug was released at simulated gastric fluid (SGF, pH 1.2, 2 h), however optimum drug released was found into simulated intestinal fluid (SIF, pH 6.8, 3 h) i.e. 5.33 to 31.33% and into simulated colonic fluid (SCF, pH 7.2, 18 h) i.e. 32.13 to 87.12% correspondingly. Scanning electron microscopy (SEM) revealed that the microbeads were consisting of semispherical and wrinkled rough surfaces. Further, the rat caecal contents (2 and 4% w/v) release studies confirmed for complete polymeric degradation by colonic enzymes. The release kinetics and mathematical modeling studies carried out for optimized formulation shown that the optimized formulations were of non fickian mechanism (n=0.49 to 0.74) type governed by both diffusion and erosion controlled following Higuchi and Korsemeyer peppas model fittings. Conclusion: It can be concluded from the study that the optimized MLM formulations may be effective for colon targeting and treating inflammatory bowel disease.

Targeted proteome analysis with isotope-coded protein labels for monitoring the influence of dietary phytochemicals on the expression of cytoprotective proteins in primary human colon cells

Cytoprotective effects by upregulating cellular expression levels of antioxidant proteins are attributed to a significant number of food ingredients. Evaluation of those cytoprotective effects and identification of the most active components requires reliable and comprehensive proteomic strategies. Thus, promising potential bioactive ingredients could be determined for the prevention of various diseases, including colon cancer formation. We established a multiplexed nanoLC–MS/MS targeted proteomic method, operated in scheduled selected reaction monitoring mode (sSRM), to record modulation of the expression levels of six major antioxidant proteins induced by dietary phytochemicals. Relative quantification was achieved by isotope-coded protein labels (ICPLs) and based on two to three proteotypic peptides per target protein. The assay provided accurate (mean relative error 6.4%) and precise (mean RSD 7.4%) quantification. Incubation experiments were carried out in primary human colon epithelial cells (HCoEpiCs) and revealed significant upregulation of NAD(P)H dehydrogenase [quinone] 1 (up to threefold) and thioredoxin reductase 1 (up to twofold) by 10μM sulforaphane (from broccoli), 5μM carnosol (rosemary), and 20μM cinnamaldehyde (cinnamon). The latter two substances additionally upregulated heme oxygenase-1 and were identified as the most active components in the test set. The results provide additional evidence for nutritive cytoprotection in human colon cells. SignificanceTargeted proteome analysis using LC coupled to scheduled selected reaction monitoring (sSRM)-MS is a highly flexible and reliable method to monitor protein expression profiles. The present study screened modulators occurring in food, which may be protective against colon cancer by inducing cytoprotective enzymes. Primary human colonic epithelial cells were used because they model the conditions in healthy gut tissue better than immortalized cells. Thus, an LC–MS/MS-sSRM protocol was established and validated including relative quantification of cytoprotective protein expression by isotope-coded protein labels, because metabolic labelling cannot be applied for primary cells. The present study demonstrated that the major components of cinnamon and rosemary, respectively, i.e. cinnamaldehyde and carnosol, are potent alimentary candidates to increase the expression of cytoprotective enzymes in the human colon. Among the investigated enzymes, NAD(P)H dehydrogenase [quinone] 1 (NQO1) was most susceptible towards modulation by phytochemicals. NQO1 exerts its cytoprotective activity by detoxifying electrophilic and oxidative xenobiotics with quinone structure.

Mesoporous silica nanoparticle based enzyme responsive system for colon specific drug delivery through guar gum capping

In the global context of increasing colonic diseases, colon specific oral drug delivery systems have shown promise as an effective therapeutic modality. Herein, we developed a mesoporous silica nanoparticle (MSN) based enzyme responsive materials for colon specific drug delivery. We have utilized guar gum, a natural carbohydrate polymer as a capping layer to contain a model drug, such as 5-flurouracil (5FU) within the mesoporous channels of MSN. Analytical characterization including electron microscopy, PXRD, nitrogen sorption, thermogravimetric analysis and FTIR, confirmed that the synthesized MSN with size less than 100nm is of MCM-41type. The studies further showed that the MSN maintained their discrete nanoparticle identity after guar gum capping through non-covalent interaction. The release of 5FU from guar gum capped MSN (GG-MSN) was specifically triggered via enzymatic biodegradation of guar gum by colonic enzymes in the simulated colonic microenvironment. Subsequently, the released drug manifested anticancer activity in colon cancer cell lines in vitro confirmed by flow cytometry and biochemical assay. The drug loaded GG-MSN system also demonstrated near perfect ‘zero release’ property in absence of enzymes in different simulated conditions of the gastrointestinal tract. Our study provides an important intermediate step to apply such GG-MSN based engineered nanomaterials for further detailed in vivo investigation.

СУЧАСНИЙ СТАН СТВОРЕННЯ, ВИРОБНИЦТВА ТА ДОСЛІДЖЕННЯ ТАБЛЕТОВАНИХ ЛІКАРСЬКИХ ПРЕПАРАТІВ. Повідомлення 23. Характеристика розробки, дослідження та використання нових терапевтичних таргет-систем із регульованим вивільненням для колонотерапії.

Узагальнено дані вітчизняних і закордонних літературних джерел щодо характеристики, переваг застосування, класифікації та технологічних аспектів розробки колонотерапевтичних систем із контрольованим вивільненням і специфічним всмоктуванням діючої речовини