Homogenates Of Small Intestine Research Articles

SOURCES OF SUPEROXIDE ANION RADICAL IN SMALL INTESTINE TISSUES IN RATS SUBJECTED TO SURGICAL TRAUMA SIMULATED UNDER EXPERIMENTAL MODEL OF POSTTRAUMATIC STRESS DISORDER

The sources of superoxide anion radical (.О ) in the tissues of the small intestine in rats subjected to surgical trauma simulated under an experimental model of posttraumatic stress disorder (PTSD) were investigated. The study involved 42 white Wistar rats weighing 210-230 g, divided into 6 groups: group 1 comprised intact animals, group 2 included animals with the PTSD induced through single-prolonged stress (SPS), group 3 consisted of rats subjected to a sham surgical operation, group 4 comprised animals undergoing laparotomy, group 5 involved rats undergoing a sham surgical operation following SPS, and group 6 included animals undergoing laparotomy under modeled SPS. The rate of .О generation in the small intestine homogenate was measured spectrophotometrically using the nitroblue tetrazolium test. The .О production by NADPH-dependent (microsomal and NO synthase) electron transport chains (ETC), NADH-dependent (mitochondrial) ETC and leukocyte NADPH oxidase was assessed. The findings obtained have demonstrated that experimental SPS modeling leads to an increase in oxidative stress in the small intestine tissues of rats. This is manifested by an increase in the rate of .О formation with the participation of microsomes, mitochondria and leukocyte NADPH oxidase. On the 7th day after laparotomy under the experimental PTSD model, the .О production in the tissues of the small intestine by different sources (microsomes, mitochondria and leukocyte NADPH oxidase) exceeds their values obtained after a single laparotomy or after performing a sham operation under single long-term stress.

NITRIC OXIDE METABOLISM IN RAT SMALL INTESTINE TISSUES FOLLOWING SURGICAL TRAUMA REPRODUCED IN EXPERIMENTAL MODEL OF POSTTRAUMATIC STRESS DISORDER

The article investigates the parameters of the nitric oxide (NO) system in the small intestine tissues of rats subjected to surgical trauma within an experimental model of post-traumatic stress disorder (PTSD). The study involved 42 white Wistar rats weighing 210-230 g, divided into 6 groups: Group 1 comprised intact animals, Group 2 included animals with the PTSD induced through single-prolonged stress (SPS), Group 3 consisted of rats subjected to a sham surgical operation, Group 4 comprised animals undergoing laparotomy, Group 5 involved rats undergoing a sham surgical operation following SPS, and Group 6 included animals undergoing laparotomy under modeled SPS. Nitric oxide synthase (NOS) activity in small intestine homogenates was assessed using spectrophotometric methods; peroxynitrite formation was determined by analyzing the content of peroxynitrite of alkali and alkaline earth metals. The study has demonstrated the SPS results in evident signs of nitrosative stress in the small intestine tissues of rats: it enhances NOS activity by activating the inducible isoform, reduces the constitutive NOS activity and coupling, and elevates the concentration of peroxynitrites of alkali and alkaline-earth metals. On the 7th day following laparotomy under PTSD modelling, nitrosative stress indicators in the small intestine tissues such as total and inducible NOS activity, as well as peroxynitrite concentrations of alkaline and alkaline-earth metals, significantly surpassed their levels following a single laparotomy under simulated single prolonged stress.

Changes in the Metabolism of Fucose-Containing Biopolymers in Rat Gastrointestinal Tissues under Immobilization Stress

The features of fucoglycoprotein metabolism in blood serum and tissues of gastrointestinal tract of rats in the dynamics of experimental stress on 21, 35, 60, 90 days of observation were considered. In blood serum and in homogenates of liver, stomach and small intestine of immobilized rats multidirectional changes in the level of fucose and fucosidase activity were observed. They are manifested by a decrease in the amount of total fucose in blood serum and liver of rats against the background of low activity of the enzyme degrading fucoglycoproteins. The same changes were detected in the tissues of the gastric and small intestine (except on day 35 of the experiment, when the growth of fucose and fucosidase was visualized), which may indicate a change in metabolism toward anabolism. These changes correlate with an increase in the concentration of corticosterone in the blood serum of the rats.

MARKERS OF CONNECTIVE TISSUE DEGRADATION IN THE SMALL INTESTINE OF RATS UNDERGOING SURGICAL TRAUMA REPLICATED UNDER EXPERIMENTAL POST-TRAUMATIC STRESS DISORDER

The objective of this experiment is to study the indices of the depolymerisation of biopolymers in the small intestine connective tissue of rats undergoing surgical trauma replicated under post-traumatic stress disorder. The study was carried out on 42 white rats. The findings obtained have shown that the experimental modelling of posttraumatic stress disorder (single prolonged stress) significantly elevates the concentration of free hydroxyproline (by 44.9%, P<0. 001), hexuronic acids (by 47.0%, P<0.001), and N-acetylneuraminic acid (by 46.2%, P<0.001), indicating depolymerisation of the extracellular matrix components, collagen, proteoglycans, and sialoglycoproteins, in this organ. On the 7th day after laparotomy performed under the experimental model of posttraumatic stress disorder, the content of free hydroxyproline, hexuronic acids, and N-acetylneuraminic acid in the small intestine homogenate significantly exceeded the respective values obtained after the separate laparotomy and "sham" surgical operation performed under simulated single prolonged stress.

Experimental infection with Schistosoma mansoni isolated from the wild rodent Holochilus sciureus shows a low parasite burden but induces high schistosomiasis severity in BALB/c mice.

Wild mammals, especially rodents, can participate in the life cycle of Schistosoma mansoni; however, the impact of these parasite strains on the severity of schistosomiasis remains unclear. The aim of this study was to comparatively evaluate the parasitological and immunopathological alterations induced by an S. mansoni strain isolated from the wild rodent Holochilus sciureus (HS strain) and a parasite strain isolated from a human (LE strain) in experimentally infected mice. Male BALB/c mice were subcutaneously infected with 50 cercariae/mouse of either the HS or the LE strain and were evaluated for 12 weeks. In the experimental groups, the parasite burden was estimated by worm and egg (feces and tissues) count, and immunopathological alterations were evaluated in the liver and intestines. Compared to experimental infection with the LE parasite strain, HS-infected mice showed reduced number of parasite worms but higher fecundity rate, significant reduction in IL-5, IL-10 and IL-13 concentrations, lower EPO-activity in liver homogenate and higher concentrations of TNF-α, IFN-γ, IL-12 and IL-17 in the small intestine homogenate. Moreover, HS infection resulted in higher concentrations of NO end-products in both the liver and intestine, suggesting a predominance of the Th1/Th17 immune response. HS-infected mice also showed higher plasma transaminase levels, formed larger granulomas, and had a higher mortality rate in comparison with LE-infected mice. Data indicate that BALB/c mice infected with the HS strain of S. mansoni showed reduced susceptibility to the parasite but stronger tissue inflammation and high disease severity.

In vitro stability and ex vivo absorption of thymol monoglucosides in the porcine gut

Thymol α-D-glucopyranoside (TαG) and thymol β-D-glucopyranoside (TβG) are believed to have different kinetic behaviours in the porcine gut than its parent aglycon thymol. However, recently, it was shown that concentrations of both glucosides decreased rapidly in the stomach and proximal small intestine following oral supplementation to piglets as did thymol. Yet, the stability of thymol glucosides in gut contents and their absorption route remains obscure. Therefore, a series of in vitro incubations were performed, simulating the impact of pH, digestive enzymes, bacterial activity and mucosal extracts on stability of these glucosides. Their absorption mechanisms were investigated using the Ussing chamber model in the presence or the absence of inhibitors of sodium-dependent glucose linked transporter 1 and lactase phlorizin hydrolase. Both glucosides remained intact at physiological pH levels in the presence of digestive enzymes. Recoveries from TαG and TβG were below 90% when incubated with small intestinal homogenates from the distal jejunum or from all sampled sites, respectively. However, no aglycon could be detected in these samples. Bacterial inoculum of the small intestine, on the other hand, hydrolysed TβG quickly with up to 44% of free aglycon appearing. TαG proved more resistant to porcine gastro-intestinal bacterial glucosidases with only trace amounts (<1%) of free thymol at the end of the incubations. Electrophysiological measurements in Ussing chambers did not suggest active transport of the glucosides. Mucosal TαG and TβG concentrations were unchanged between start and end of the absorption measurements. Additionally, no TαG and only a very limited amount of TβG were retrieved from the serosal side. Tissue associated concentrations, although marginal (<1% of luminal concentration), were mainly as intact glucoside or as aglycon for TαG and TβG, respectively. Addition of both inhibitors significantly increased the amount of intact glucosides retrieved from the mucosal tissues as compared to controls. In conclusion, bacterial hydrolysis was identified as the most important source of TβG loss, whereas TαG seemed less prone to degradation or absorption in these in vitro and ex vivo models.

Comparing the Effect of Piperine and Ilepcimide on the Pharmacokinetics of Curcumin in SD Rats.

The poor bioavailability and rapid metabolism of curcumin (CUR) restrict its clinical application. Piperine (PIP), which was extracted from natural compounds, can increase the plasma concentration of curcumin in humanidad. As an artificial synthetic piperine analog, silepcimide (ILE) has significant advantages because of the low price and simple synthesis process. In this study, a simple and rapid HPLC-UV method was developed for determination of the plasma concentration of CUR, PIP,ILE and dihydrocurcumin (DHC, a metabolite of CUR) simultaneously. Meanwhile, the effects of PIP and ILE on the plasma concentration and pharmacokinetics of DHC in SD rats was studied to explore whether ILE could serve as a CUR bioavailability enhancer. The metabolic pathway of CUR was studied by comparing the differences of CUR plasma concentration between intravenous injection and oral administration over the same time period, and reacting with small intestine homogenate without microbes of SD rats. The results of drug-time curve showed that combined administration of ILE and CUR had significant effect on plasma concentrations of DHC. Repeated administration of PIP or ILE could significantly increase the plasma concentration of DHC. Plasma CUR could be detected in the samples of from intravenous injection of CUR rats, whereas, it couldn’t be detected in the plasma sample form oral administration rats. CUR incubated with intestinal homogenate without intestinal bacteria could not be transformed into DHC. In conclusion, our results show that ILE can improve the bioavailability of CUR. Additionally, it was inferred that most of the CUR was reduced to DHC by NADPH when it was absorbed from gastrointestinal tract, and our results demonstrated that this pathway might be mediated by gastrointestinal microorganisms.

Electromagnetic Fields Modify Redox Balance in the Rat Gastrointestinal Tract.

Objective: The aim of the study was to assess the influence of electromagnetic fields with divergent physical properties on the prooxidative and antioxidative balances in homogenates of the tongue, salivary glands, esophagus, stomach, and small and large intestines of rats.Material and Methods: Forty rats were randomly divided into four equal groups, namely, a control group, a group exposed to low-frequency electromagnetic fields (LF-EMFs; frequency: 50 Hz; intensity: 10 kV/m; magnetic induction: 4.3 pT), a group exposed to radiofrequency electromagnetic fields (RF-EMFs) emitted by mobile phones (frequency: 900 MHz), and a group exposed simultaneously to LF-EMFs and RF-EMFs emitted by mobile phones. After 28 consecutive days of the experiment, the following pro- and antioxidative markers were assessed in the gastrointestinal tract homogenates: superoxide dismutase (SOD) and its two isoenzymes (Mn-SOD, Cu,Zn-SOD) catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), total antioxidative capacity (TAC), total oxidative status (TOS), and malondialdehyde (MDA).Results: In rats exposed to LF-EMFs, higher concentrations of the markers of prooxidant processes, MDA or TOS, were observed in the salivary glands, esophagus, and small intestine homogenates in comparison with the control group. Additionally, in the group of rats opposite to the control, antioxidant activity was observed. The main differences included a higher activity of Cu,Zn-SOD in homogenates of the tongue, salivary glands, and esophagus as well as decreased activity of CAT in homogenates of the tongue, esophagus, and small intestine. In animals exposed to RF-EMFs, the concentration of TOS was higher in the large intestine than in control rats. The main difference of antioxidant activity was presented by decreased Cu,Zn-SOD in homogenates of the salivary glands, stomach, small and large intestine as well as CAT in homogenates of the tongue, esophagus, stomach, and small and large intestine. Moreover, in rats exposed simultaneously to LF-EMFs and RF-EMFs, a lower concentration of TOS was observed. Antioxidant activity was presented by a decreased activity of CAT in homogenates of the tongue, esophagus, stomach, and small and large intestine in comparison to the control group.Conclusion: Among those applied in the study, electromagnetic fields of a low-frequency caused the most significant disturbances of oxidative stress in the rat gastrointestinal tract.

Spondias pinnata bark extract- an ameliorator of inflammatory derangement in etoposide induced mucositis: An experimental approach.

Background and Aim:Mucositis, one of the vulnerabilities of chemotherapy, affects the physiological activities and therapeutic strategies of patients because it can affect the normal cell population. Etoposide is a commonly used chemotherapeutic agent for cancers such as oral, lung, and gastrointestinal. In addition to the abnormal metabolic processes in the body caused by tumorigenesis, new metabolic alterations can occur, such as oxidative stress, antioxidant imbalance, and inflammatory reactions, all of which can contribute to existing patient vulnerability. Therapeutic adjuvants can help overcome these toxic effects. Spondias pinnata is a tropical tree omnipresent in the coastal and Western Ghat section of India that is used for culinary purposes and as a local analgesic. Therefore, we aimed to study the anti-inflammatory effects of S. pinnata in an etoposide-induced mucositis rat model.Materials and Methods:Small intestinal tissue homogenates from albino Wistar rats were used to estimate the levels of glutathione (GSH) and nitric oxide (NO), and activities of total antioxidant (TAO), myeloperoxidase (MPO) and Na+-K+ ATPase. The animals were grouped into: (1) normal control, (2) etoposide-induced mucositis (65 mg/kg bodyweight, single IP dose), (3) S. pinnata control group, and (4) etoposide followed by S. pinnata bark extract (200 mg/kg bodyweight, once in a day). Animals were sacrificed after 24, 48, 72, and 96 h and compared with that of the normal control group (n=6). Statistical analysis was performed using EZR software.Results:We observed a significant decrease in the TAO and GSH levels with a marked increase in NO, MPO, and Na+-K+ ATPase activity in the mucositis group. A tendency to recover from the decreased TAO and GSH levels existed in the treated group, showing the protective effects of S. pinnata bark extract against mucositis. In addition, this extract also showed anti-inflammatory effects as reflected by the recovery in MPO levels at the end of 96 h. Maintenance of Na+-K+ ATPase activity in the treated group demonstrates the protective effects of the extract against the increased levels observed in the etoposide-induced mucositis group.Conclusion:This study revealed the protective effects of S. pinnata bark extract against the oxidative and inflammatory changes that occurred during the development ofmucositis. This would decrease the pathological burden during chemotherapy and prevent any hurdles in therapeutic modalities.

Динамика хемилюминесценции в тонкой кишке на фоне анестетического прекондиционирования при геморрагической гипотензии

Introduction. The major pathogenetic factor of massive blood loss is hypoxia, which triggers activation of free-radical oxidation (FRO) processes in organs and tissues and the systemic inflammatory response. A universal factor of multiple organ dysfunction in blood loss is altered intestinal wall permeability with translocation of microflora and toxins into the systemic circulation during reperfusion. Recently, much of the attention has been focused on effects of anesthetic preconditioning, including during operations associated with hemorrhagic hypotension (HH). The aim of this study was to evaluate in experiment the dynamics of small intestinal FRO in HH during the use of the anesthetic sevoflurane, which has an effect of anesthetic preconditioning. Methods. Experiments were performed on 105 white male rats divided into two groups; groups 1 and 2 were exposed to HH with ether or sevoflurane as the anesthetic, respectively. Two groups of intact animals treated with ether or sevoflurane were used as the controls. Five animals died during the experiment. To evaluate FRO processes, samples of the duodenum, jejunum, and ileum were taken at 15 min, 30 min, 1 h, and 2 h of HH. The chemiluminescence (CL) study of small intestine homogenates was performed according to the Farukhutdinov method on a Fluorate ABLF-2T chemiluninometer. The following FRO indexes were recorded: spontaneous luminosity (SL), flash (F), and light sum (L∑). Significance of differences was determined with the Mann-Whitney test. Results. In the sevoflurane group 2 compared to the ether group after 15 min of HH, SL was increased in the jejunum by 33%; F was decreased in the duodenum by 50%, in the jejunum by 24%, and in the ileum by 36%; L∑ was decreased in the duodenum by 36%, in the jejunum by 45%, and in the ileum by 52%. At 30 min, SL in the jejunum was increased by 80%. In the HH+sevoflurane group, F was decreased in the duodenum by 38%, in the jejunum by 22%, and in the ileum by 27%; L∑ in the duodenum was decreased by 44%, in the jejunum by 45%, and in the ileum by 67%. After 1 h of HH+sevofluran, SL was increased in the jejunum twofold, in the duodenum by 38% and in the ileum by 15%; F was decreased in the duodenum by 67% and in the jejunum by 43%; L∑ in the duodenum was decreased by 62%, in the jejunum by 60%, and in the ileum by 70% compared to the ether group. After 2 h of HH+sevofluran, SL was increased in the jejunum and ileum by 80% and 67%, respectively, compared to the ether group. In this process, L∑ in the duodenum was decreased by 24% and in the jejunum by 15%. Conclusion. The HH+diethyl ether exposure was associated with activation of FRO processes in the small intestine. The sevoflurane preconditioning provided a significant restriction of oxidative stress in the rat small intestine due to activation of the antioxidant system in the duodenum, jejunum, and ileum at 1 h, 15 min, and 30 min of HH, respectively.

Effects of Cola anomala (K. Schum.) water/ethanol pods extract on the inflammation and intestinal secretion in lipopolysaccharide-induced diarrhea

Diarrhea is one of the leading causes of death among children in low and low-middle income countries and the management of this pathology is still a problem in these regions. The water/ethanol extract of the pods of Cola anomala (KEO) has been shown to possess antimicrobial and antidiarrheal effects in Shigella flexneri-induced diarrhea, but whether KEO is active on the toxemic part of this diarrhea is unknown. This study was undertaken to evaluate the effects of KEO on the intestinal secretion and inflammation induced by intraperitoneal administration of lipopolysaccharide (LPS). KEO obtained by maceration in water/ethanol (1:1) was administered orally (25, 50 and 100 mg/kg of body weight) against LPS-induced diarrhea in mice. The mass of feces, the intestinal nitric oxide (NO) and prostaglandin (PGE2) contents as well as myeloperoxidase (MPO) activity were assessed. KEO was also tested on LPS-induced enteropooling in rats. In this experiment, the intestinal fluid and its electrolytes (Na+, K+ and Cl-) contents were determined as well as NO, PGE2, TNF-α and IL-1β levels in the small intestine homogenate. Indomethacin (5 mg/kg) was used as reference drug. KEO significantly (p &lt; 0.001) reduced stools excretion, NO content and MPO activity in intestine but did not affect PGE2 in LPS-induced diarrhea. On the enteropooling model, KEO showed no effect on the intestinal fluid and electrolyte excretion, PGE2, TNF-α and IL-1β contents, but significantly (p &lt; 0.05) reduced the NO production. This study suggests that KEO does not have antisecretory effect, but has anti inflammatory activities. It can be concluded that the anti-toxemic effect of KEO contributes less to its antidiarrheal activity in infectious diarrhea.

Development and validation of an LC-MS/MS method for the quantitative analysis of milciclib in human and mouse plasma, mouse tissue homogenates and tissue culture medium

Milciclib is a promising cyclin-dependent kinase inhibitor currently in phase II clinical trials to treat several types of cancer. The first bioanalytical method for the quantitative analysis of milciclib in several biomatrices using liquid chromatography-tandem mass spectrometry is described here. This method was fully validated in human plasma according to FDA and EMA guidelines, and partially validated in mouse plasma, homogenates of mouse brain, kidney, liver, small intestine, spleen, and tissue culture medium. Palbociclib, an analog compound, was used as internal standard. A simple and fast sample pre-treatment by protein precipitation with acetonitrile was used, leading to efficient extraction of the analyte with recoveries between 95–100%. Chromatographic separation was achieved with a C18 analytical column and a gradient elution using 10 mM ammonium bicarbonate in water and 10 mM ammonium bicarbonate in water-methanol (1:9, v/v). This assay was selective, accurate, precise and linear in the concentration range of 1−1000 ng/mL. Moreover, samples above the upper limit of quantification can be integrally diluted up to 10-fold prior to analysis. The use of human plasma as a surrogate matrix to quantify milciclib in tissue culture medium and mouse matrices resulted in acceptable accuracy and precision, however tissue culture medium samples required a dilution with human plasma prior the pre-treatment. All performance parameters of the method complied with the acceptance criteria recommended by the guidelines, except for the carry-over, which was slightly above (22.9% of the lower limit of quantification) the recommended percentage (20%). Therefore, additional measures were taken to assure data integrity. Stability of milciclib in all matrices was evaluated, and in some matrices the analyte was unstable under the tested conditions. It is therefore recommended to keep these samples as briefly as possible at room temperature during the pre-treatment, and to store them at –70 °C to avoid analyte degradation. This method was successfully applied to support preclinical pharmacokinetic studies of milciclib.

Rat intestinal homogenate and pancreatic juice can induce the Z-isomerization of all-E-lycopene in vitro

Lycopene is one of the carotenoids often consumed by humans in their diet. Although lycopene exists mainly in the form of the all E-isomer in foods, the considerable quantity of its Z-isomers is found in the human plasma and liver. This observation suggested that the lycopene all-E-isomer was converted into Z-isomers in the human body. In this study, the Z-isomerization of the all-E-isomer was induced in vitro by the pancreatic juice and small intestinal homogenate of male rats under the conditions of 37 °C, pH = 7.5, nitrogen and darkness, as well as shaking. After 2 hours, the proportion of the all E-isomer decreased to 25% and Z-isomer amounts increased relatively. The converted products were identified as 5, 9, and 11 Z-isomers by electronic absorption spectroscopy and mass spectrometry (MS). The observations from this experiment suggested that the Z-isomerization site of the lycopene all E-isomer was located in the small intestinal wall of the rat.

Bioanalytical assay for the novel TRK inhibitor selitrectinib in mouse plasma and tissue homogenates using liquid chromatography-tandem mass spectrometry

Selitrectinib is a next generation tropomyosin receptor kinase (TRK) inhibitor developed to overcome acquired resistance to first generation TRK inhibitors. The drug is a cyclic analogue of larotrectinib. An existing bioanalytical assay for larotrectinib was therefore redesigned for selitrectinib. The assay used liquid chromatography-electrospray tandem mass spectrometry in positive selected reaction monitoring mode. Mouse plasma and tissue homogenates of brain, heart, kidney, liver, lung, small intestine, spleen, and testis were pretreated using acetonitrile protein precipitation with larotrectinib added as internal standard. Successful validation using current guidelines was obtained in the range 0.5–1000 ng/ml. Precision was within 5–12% and accuracy within 91–108% for all matrices investigated. The drug was stable in all matrices under the relevant storage conditions. Pharmacokinetics and tissue distribution of selitrectinib were monitored in a pilot study in mice demonstrating the applicability of the presented assay.

Metabolites of Tryptophane and Phenylalanine as Markers of Small Bowel Ischemia-Reperfusion Injury

Abstract Ischemic-reperfusion injury of the small intestine is an acute clinical condition with high mortality rate. This study describes the changes in levels of phenylalanine and tryptophan metabolites in intestinal homogenates and urine samples of Wistar male rats after 60 minutes of mesenteric ischemia and different reperfusion periods (1, 24, 30 hours) in comparison with a control group without the ischemia. The ischemic-reperfusion injury was quantified by the histopathological injury index. The levels of serotonin, epinephrine, and norepinephrine were determined in the intestinal homogenate and epinephrine, vanillylmandelic acid, and the 5-hydroxyindoleacetic acid was analyzed in urine using the HPLC method. The statistically significant increased level of serotonin, epinephrine and norepinephrine were detected in the intestinal samples after 24 hours of reperfusion (p&lt;0.01); even the most elevated serotonin level was observed after one hour of reperfusion (p&lt;0.001). A statistically significant decreased level of vanillylmandelic acid was observed after one hour of reperfusion, but it significantly increased after 24 hours (p&lt;0.05) in urine. The elevated level of the 5-hydroxyindoleacetic acid after one hour and 24 hours after reperfusion (p&lt;0.05) were determined in the urine. The most significant elevated epinephrine level was observed after 24 hours of reperfusion (p&lt;0.001) in urine. Results showed a potential role of serotonin as an early biomarker (after one hour of reperfusion) of small intestinal damaged homogenate, while the best predictor of intestinal injury in urine was epinephrine, which was elevated after 24 hours.

АКТИВНІСТЬ СУПЕРОКСИДДИСМУТАЗИ І КАТАЛАЗИ У СТІНЦІ ТОНКОЇ КИШКИ, СЕРЦІ І ПЕЧІНЦІ ПРИ ЕКСПЕРИМЕНТАЛЬНОМУ ЗАСТОСУВАННІ КАРАГІНАНУ

Вступ. Одним з провідних механізмів формування синдрому органних дисфункцій при різних патологіях є гіперпродукція активних форм оксигену, які запускають процеси пероксидного окиснення в органах і тканинах, віддалених від вогнища ураження [6]. Виникнення оксидативного стрессу зумовлене також зниженням ефективності антиоксидантного захисту.Тому, метою нашого дослідження було встановити активність супероксиддисмутази та каталази в тканинах тонкої кишки, серця і печінки тварин при застосуванні 1% розчину κ-карагінану.Матеріали та методи дослідження. Дослідження проведено на 24 білих нелінійних самцях-щурах. Тваринам дослідної групи забезпечували вільний доступ до 1,0 % розчину карагінану у питній воді протягом 1 місяця. У відібраних зразках тонкої кишки, серця і печінки оцінювали активність супероксиддисмутази і каталази.Результати досліджень та їх обговорення. Встановлено, що застосування 1 % розчину κ-карагінану щурам у питній воді зумовлювало активацію ензимної ланки антиоксидантної системи захисту. Встановлено зростання активності СОД в гомогенаті стінки тонкої кишки (в 1,32 раза, р&lt;0,05) і печінці (в 1,30 раза, р&lt;0,05). Підвищувалася також активність каталази у гомогенаті стінки тонкої кишки (в 1,18 раза, р&lt;0,05) і печінці (в 1,13 раза, р&lt;0,05). При цьому коефіцієнт антиоксидантного захисту в стінці кишки становив 1,11 (р&lt;0,05), в міокарді – 1,0 і в печінці – 1,15 (р&lt;0,05).Висновок. Пероральне застосування 1% розчину карагінану щурам веде до статистично значимої активації ензимної ланки антиоксидантного захисту в стінці тонкої кишки і печінці, що характеризується підвищенням, відповідно, активності СОД (на 31,8 % і 29,7 %) і каталази (на 18,3 % і 12,9 %), р&lt;0,05.

Selective and Concentrated Accretion of SN-38 with a CEACAM5-Targeting Antibody–Drug Conjugate (ADC), Labetuzumab Govitecan (IMMU-130)

Labetuzumab govitecan (IMMU-130), an antibody-drug conjugate (ADC) with an average of 7.6 SN-38/IgG, was evaluated for its potential to enhance delivery of SN-38 to human colonic tumor xenografts. Mice bearing LS174T or GW-39 human colonic tumor xenografts were injected with irinotecan or IMMU-130 (SN-38 equivalents ∼500 or ∼16 μg, respectively). Serum and homogenates of tumors, liver, and small intestine were extracted, and SN-38, SN-38G (glucuronidated SN-38), and irinotecan concentrations determined by reversed-phase HPLC. Irinotecan cleared quickly from serum, with only 1% to 2% injected dose/mL after 5 minutes; overall, approximately 20% was converted to SN-38 and SN-38G. At 1 hour with IMMU-130, 45% to 63% injected dose/mL of the SN-38 was in the serum, with >90% bound to the ADC over 3 days, and with low levels of SN-38G. Total SN-38 levels decreased more quickly than the IgG, confirming a gradual SN-38 release from the ADC. AUC analysis found that SN-38 levels were approximately 11- and 16-fold higher in LS174T and GW-39 tumors, respectively, in IMMU-130-treated animals. This delivery advantage is amplified >30-fold when normalized to SN-38 equivalents injected for each product. Levels of SN-38 and SN-38G were appreciably lower in the liver and small intestinal contents in animals given IMMU-130. On the basis of the SN-38 equivalents administered, IMMU-130 potentially delivers >300-fold more SN-38 to CEA-producing tumors compared with irinotecan, while also reducing levels of SN-38 and SN-38G in normal tissues. These observations are consistent with preclinical and clinical data showing efficacy and improved safety. Mol Cancer Ther; 17(1); 196-203. ©2017 AACR.

Quercetin Ameliorate Oxidative Stress-Induced Small Intestine Toxicity by Mefenamic Acid

The objectives of this study were to determine the involvement of oxidative stress and the ameliorative effect of quercetin (QUR) on mefenamic acid-induced small intestine toxicity by measuring the level of superoxide radical, hydrogen peroxide (H2O2), protein carbonylation (PC), and advanced oxidation protein products (AOPPs). In this experiment, a small intestine was taken from male rats (Rattus novergicus). Samples then homogenized and divided into three groups with; T1 served as control which contains small intestine homogenate only; T2 which contains small intestine homogenate + 500 mg of mefenamic acid; and T3 which contains small intestine homogenate + 500 mg of mefenamic acid + 250 mg/L of quercetin. After treatment, every 15-minute superoxide radical, H2O2, PC, and AOPPs levels were estimated. The results revealed that mefenamic acid increased the level of superoxide radical, H2O2, PC, and AOPPs, while QUR decreases the level of all parameters. These results indicated that mefenamic acid induce small intestine toxicity through oxidative stress mechanisms as can be seen from the increasing of superoxide radical, H2O2, PC, and AOPPs levels. Also, the results indicated that QUR could inhibit these process as can be seen from the decreasing of all parameters.

Pharmacokinetic of 3H-deacetylasperulosidic acid in mice

Background: An investigation was conducted to determine the fate of the iridoid derivative deacetylasperulosidic acid (DAA) after oral application to mice.Methods: DAA was extracted from Morinda citrifolia leaf and purified by preparative HPLC. The identity was verified by MS and NMR spectroscopy. A sample of DAA was radioactively labelled with tritium and applied to mice by gavage. The pharmacokinetic of the radioactivity was investigated in blood, organs, urine and feces. Metabolites were isolated in blood and urine by HPLC and identified by LC-MS. In vitro incubation of DAA with mouse duodenum and liver homogenate and human fecal bacteria was performed and possible metabolites were separated with HPLC.Results: DAA was rapidly absorbed and excreted mainly via the kidneys with a half-life of 30 minutes. Radioactivity was present in all organs with highest concentrations in kidney and liver. Almost 100% of the radioactivity isolated from urine and organs could be identified as unchanged DAA. Additionally, no metabolism could be observed after in vitro incubation of DAA with mouse small intestine or liver homogenate, however, a total breakdown of the molecule was observed after incubation of DAA with human intestinal bacteria.Conclusions:The absorption and excretion of glycosides such as DAA in mammals without hydrolysis is possibly a defense mechanism of animals against the toxicity of these compounds. Key words: Deacetylasperulosidic acid, DAA, tritium label, pharmacokinetic,iridoid, metabolism

Novel Thioester Prodrug of N-acetylcysteine for Odor Masking and Bioavailability Enhancement.

The mucolytic N-acetylcysteine (NAC) is used to control the excessive mucus secretion if mucus is the underlying cause of broncho-constriction. Its major drawbacks are poor bioavailability due to extensive first pass effect, poor lipophilicity, high protein binding and offensive odor. For minimizing above shortcomings of NAC, in present study thioester (A1) prodrug of NAC was synthesized by conventional as well as microwave-assisted methods. Release studies of A-1 were carried out using HPLC and pharmacological evaluation was performed in ovalbumin-induced model of pulmonary inflammation in Sprague dawley rats. A-1 was found to be stable in HCl buffer, phosphate buffer, stomach homogenates but furnished 30% NAC in 6h and 1.7% of NAC in 4h when incubated with small intestinal and liver homogenates respectively. Upon oral administration of A-1 to rats, 4.85% NAC was detected in blood at 8h. Urine samples pooled over a period of 24h exhibited 0.75% NAC while negligible concentration was found in 24 h pooled samples of feces. The findings of this preliminary investigation demonstrated significant effects of thioester prodrug A-1 as compared to NAC through reduction of lung inflammation, airway eosinophilia and reversal of lung function parameters in ovalbumin- challenged rats at half the equimolar dose of NAC. Interestingly masking thiol group through thioester formation resulted in odorless prodrug. We propose that thioester prodrug using palmitic acid as a carrier is a promising strategy to enhance bioavailability of NAC by increasing its lipophilicity/ absorption and minimizing its first pass metabolism.