Evaluation of acute and subacute toxicity of sodium taurodeoxycholate in rats.

Taurodeoxycholate (TDCA) inhibits various inflammatory responses suggesting potential clinical application. However, the toxicity of TDCA has not been evaluated in detail in vivo. We investigated the acute toxicity and 4-week repeated-dose toxicity of TDCA following intravenous infusion under Good Laboratory Practice regulations. In the sighting study of acute toxicity, one of two rats (one male and one female) treated with 300 mg/kg TDCA died with hepatotoxicity, suggesting that the approximate 50% lethal dose of TDCA is 300 mg/kg. Edema and discoloration were observed at the injection sites of tails when rats were infused with 150 mg/kg or higher amount of TDCA once. In 4-week repeated-dose toxicity study, no treatment-related mortality or systemic changes in hematology and serum biochemistry, organ weights, gross pathology, or histopathology were observed. However, the tail injection site showed redness, discharge, hardening, and crust formation along with histopathological changes such as ulceration, edema, fibrosis, and thrombosis when rats were infused with 20 mg/kg TDCA. Taken together, TDCA induced no systemic toxicity or macroscopic lesions at the injection site at a dose of 10 mg/kg/day, which is 33 times higher than the median effective dose observed in a mouse sepsis model. These findings suggest that TDCA might have a favorable therapeutic index in clinical applications.

Genipin induces developmental toxicity through oxidative stress and apoptosis in zebrafish.

Genipin, an iridoid substance, is mainly derived from Gardenia jasminoides Ellis of the traditional Chinese medicine and is widely used in raw materials for the food additive gardenia blue and biological materials. The developmental toxicity of genipin has not been investigated, and its underlying mechanism is unclear. Therefore, in this study we attempt to investigate the potential developmental toxicity of genipin in zebrafish embryos/larvae. The results showed zebrafish embryos treated with 50 µg/ml dose of genipin display inhibited hatching rates and body length. The pericardial edema was observed. It was also found that genipin could induce cardio-toxicity, hepatotoxicity and nephrotoxicity in zebrafish larvae. After genipin treatment, the suppression of antioxidant capacity and increase of oxidative stress were showed for the triggered generation of ROS and MDA, and decreased activity of SOD. Compared with the 0.5% DMSO group, a number of apoptotic cells in zebrafish were increased after genipin exposure. By measuring marker gene expression with the using of qRT-PCR, we proposed that developmental toxicity after genipin treatment might be associated with oxidative stress and apoptosis increase. Our research offers a better understanding for developmental toxicity of genipin.

Therapeutic potential of genipin in various acute liver injury, fulminant hepatitis, NAFLD and other non-cancer liver diseases: More friend than foe.

Genipin is an aglycone derived from the geniposide, the most abundant iridoid glucoside constituent of Gardenia jasminoides Ellis. For decades, genipin is the focus of studies as a versatile compound in the treatment of various pathogenic conditions. In particularly, Gardenia jasminoides Ellis has long been used in traditional Chinese medicine for the prevention and treatment of liver disease. Mounting experimental data has proved genipin possesses therapeutic potential for cholestatic, septic, ischemia/reperfusion-triggered acute liver injury, fulminant hepatitis and NAFLD. This critical review is a reflection on the valuable lessons from decades of research regarding pharmacological activities of genipin. Of note, genipin represents choleretic effect by potentiating bilirubin disposal and enhancement of genes in charge of the efflux of a number of organic anions. The anti-inflammatory capability of genipin is mediated by suppression of the production and function of pro-inflammatory cytokines and inflammasome. Moreover, genipin modulates various transcription factor and signal transduction pathway. Genipin appears to trigger the upregulation of several key genes encoding antioxidant and xenobiotic-metabolizing enzymes. Furthermore, the medicinal impact of genipin extends to modulation of regulated cell death, including autophagic cell death, apoptosis, necroptosis and pyroptosis, and modulation of quality of cellular organelle. Another crucial effect of genipin appears to be linked to dual role in targeting uncoupling protein 2 (UCP2). As a typical UCP2-inhibiting compound, genipin could inhibit AMP-activated protein kinase or NF-κB in circumstance. On the contrary, reactive oxygen species production and cellular lipid deposits mediated by genipin through the upregulation of UCP2 is observed in liver steatosis, suggesting the precise role of genipin is disease-specific. Collectively, we comprehensively summarize the mechanisms and pathways associated with the hepatoprotective activity of genipin and discuss potential toxic impact. Notably, our focus is the direct medicinal effect of genipin itself, whereas its utility as a crosslinking agent in tissue engineering is out of scope for the current review. Further studies are therefore required to disentangle these complicated pharmacological properties to confer this natural agent a far greater potency.

Polyethylene Glycol 35 (PEG35) Protects against Inflammation in Experimental Acute Necrotizing Pancreatitis and Associated Lung Injury.

Acute pancreatitis is an inflammatory disorder of the pancreas. Its presentation ranges from self-limiting disease to acute necrotizing pancreatitis (ANP) with multiorgan failure and a high mortality. Polyethylene glycols (PEGs) are non-immunogenic, non-toxic, and water-soluble chemicals composed of repeating units of ethylene glycol. The present article explores the effect of PEG35 administration on reducing the severity of ANP and associated lung injury. ANP was induced by injection of 5% sodium taurocholate into the biliopancreatic duct. PEG35 was administered intravenously either prophylactically or therapeutically. Three hours after ANP induction, pancreas and lung tissue samples and blood were collected and ANP severity was assessed. To evaluate the inflammatory response, gene expression of pro-inflammatory cytokines and chemokine and the changes in the presence of myeloperoxidase and adhesion molecule levels were determined in both the pancreas and the lung. To evaluate cell death, lactate dehydrogenase (LDH) activity and apoptotic cleaved caspase-3 localization were determined in plasma and in both the pancreatic and lung tissue respectively. ANP-associated local and systemic inflammatory processes were reduced when PEG35 was administered prophylactically. PEG35 pre-treatment also protected against acute pancreatitis-associated cell death. Notably, the therapeutic administration of PEG35 significantly decreased associated lung injury, even when the pancreatic lesion was equivalent to that in the untreated ANP-induced group. Our results support a protective role of PEG35 against the ANP-associated inflammatory process and identify PEG35 as a promising tool for the treatment of the potentially lethal complications of the disease.

Hydrostatin-SN10 Ameliorates Pancreatitis-Induced Lung Injury by Affecting IL-6-Induced JAK2/STAT3-Associated Inflammation and Oxidative Stress.

Hydrostatin-SN1 (peptide sequence, DEQHLETELHTLTSVLTANGFQ), a kind of peptides extracted from snake venom, has been reported to have anti-inflammatory effect, but its truncated mutant hydrostatin-SN10 (peptide sequence, DEQHLETELH) on pancreatitis-induced acute lung injury has not been well documented. Interleukin- (IL-) 6-induced Janus Kinase 2/Signal Transducer and Activator of Transcription 3 (JAK2/STAT3) pathway is involved with inflammatory and oxidative stress activities and may be associated with the pathogenesis of lung injury, and related molecules were measured. Taurocholate-induced pancreatitis associated with acute lung injury was established and treated with hydrostatin-SN10. Pancreatitis was confirmed by measuring the serum levels of amylase, lipase, and trypsinogen and urinary amylase. Lung injury was determined by histologically assessing acinar cell changes. The related molecules of IL-6-induced JAK2/STAT3-associated inflammation and oxidative stress were quantitated by real time-PCR, Western blot, and/or immunochemical assay. Hydrostatin-SN10 reduced the levels of serum amylase, lipase, and trypsinogen and urinary amylase when compared with the model group (p < 0.05). Hydrostatin-SN10 significantly inhibited the IL-6-stimulated JAK2/STAT3 pathway and reduced the number of apoptotic cells via the downregulation of caspase 3 and BAX (proapoptotic) and upregulation of Bcl2 (antiapoptotic) (p < 0.05). IL-6 induced the increase in the levels of JAK2 and STAT3, which was reversed by hydrostatin-SN10 treatment (p < 0.05). In addition, hydrostatin-SN10 reduced the expression of IL-6 and TNF- (tumor necrosis factor-) α and increased the level of IL-10 (p < 0.05). On the other hand, hydrostatin-SN10 treatment increased the levels of superoxide dismutase (SOD) and reduced glutathione (GSH) and the levels of malondialdehyde (MDA) and alanine aminotransferase (ALT) (p < 0.05). These results suggest that hydrostatin-SN10 may inhibit pancreatitis-induced acute lung injury by affecting IL-6-mediated JAK2/STAT3 pathway-associated inflammation and oxidative stress.

Physicochemical and Toxic Properties of Novel Genipin Drug Delivery Systems Prepared by Mechanochemistry.

BACKGROUND: Complexes of Genipin and different water-soluble adjuvant polysaccharides, such as arabinogalactane, hydroxyethyl starch, fibergum, and oligosaccharides ß-CD and HP-ß-CD, were synthesized as drug delivery system using mechanochemical technology. METHOD: We have investigated physicochemical properties, stability, and hepatotoxicity of the synthesized complexes in solid state and aqueous solution. The formation of the complexes was evidenced by different physical and spectroscopy assays, and the stability constants of our synthesized Genipin-based complexes were also calculated. RESULTS: The HP-ß-CD inclusion complex showed the highest characteristics. We have found that the molecule of Genipin was completely included in the cyclodextrin cavity of the HP-ß-CD. This complex of Genipin has shown a 6.14-fold increase of solubility compared with the original Genipin, and more stable in solvent and solid states. CONCLUSION: The hepatotoxicity assays showed that our investigated complexes of Genipin are much safer than the original Genipin. These results suggest that new Genipin-based preparations can be synthesized with advantageous of higher stability and safety.

Secondary bile acids effects in colon pathology. Experimental mice study.

PURPOSE: To assess whether deoxycholic acid (DOC) and lithocholic acid (LCA) administered in a period of six months in a concentration of 0.25% may have a carcinogenic role in mice colon. METHODS: The study used C57BL6 female mice divided into four groups. The control group received a balanced diet and the others received diets supplemented with 0.25% DOC, 0.25% LCA and 0.125% DOC+0.125% LCA, respectively. After euthanasia, the lesions found in the resected gastrointestinal tracts were stained with hematoxylin-eosin and examined microscopically. RESULTS: No gastrointestinal tract changes were observed in the control group, while hyperplastic Peyer's patches in the small intestine, flat adenomas with mild dysplasia and chronic colitis at the level of the colon were found in all three test groups. The colonic lesions prevailed in the proximal colon. The highest number of flat adenoma lesions (8), hyperplasia of Peyer's patches (25) and chronic colitis (2) were found in mice fed with diet and LCA. CONCLUSION: Precancerous or cancerous pathological lesions could not be identified. Instead, adenomatous colonic injuries occurred in a shorter period of time (six months), compared to the reported data.

Secondary bile acids effects in colon pathology. Experimental mice study

ABSTRACTPURPOSE:To assess whether deoxycholic acid (DOC) and lithocholic acid (LCA) administered in a period of six months in a concentration of 0.25% may have a carcinogenic role in mice colon.METHODS:The study used C57BL6 female mice divided into four groups. The control group received a balanced diet and the others received diets supplemented with 0.25% DOC, 0.25% LCA and 0.125% DOC+0.125% LCA, respectively. After euthanasia, the lesions found in the resected gastrointestinal tracts were stained with hematoxylin-eosin and examined microscopically.RESULTS:No gastrointestinal tract changes were observed in the control group, while hyperplastic Peyer's patches in the small intestine, flat adenomas with mild dysplasia and chronic colitis at the level of the colon were found in all three test groups. The colonic lesions prevailed in the proximal colon. The highest number of flat adenoma lesions (8), hyperplasia of Peyer's patches (25) and chronic colitis (2) were found in mice fed with diet and LCA.CONCLUSION: Precancerous or cancerous pathological lesions could not be identified. Instead, adenomatous colonic injuries occurred in a shorter period of time (six months), compared to the reported data.

P-selectin mediates neutrophil rolling and recruitment in acute pancreatitis.

BACKGROUND: The adhesive mechanisms regulating leucocyte-endothelium interactions in the pancreas remain elusive, but selectins may play a role. This study examined the molecular mechanisms mediating leucocyte rolling along the endothelium in the pancreas and the therapeutic potential of targeting the rolling adhesive interaction in acute pancreatitis (AP). METHODS: Pancreatitis was induced by retrograde infusion of 5 per cent sodium taurocholate into the pancreatic duct, repeated intraperitoneal administration of caerulein (50 µg/kg) or intraperitoneal administration of L-arginine (4 g/kg) in C57BL/6 mice. A control and a monoclonal antibody against P-selectin were administered before and after induction of AP. Serum and tissue were sampled to assess the severity of pancreatitis, and intravital microscopy was used to study leucocyte rolling. RESULTS: Taurocholate infusion into the pancreatic duct increased the serum level of trypsinogen, trypsinogen activation, pancreatic neutrophil infiltration, macrophage inflammatory protein (MIP) 2 formation and tissue damage. Immunoneutralization of P-selectin decreased the taurocholate-induced increase in serum trypsinogen (median (range) 17·35 (12·20-30·00) versus 1·55 (0·60-15·70) µg/l; P = 0·017), neutrophil accumulation (4·00 (0·75-4·00) versus 0·63 (0-3·25); P = 0·002) and tissue damage, but had no effect on MIP-2 production (14·08 (1·68-33·38) versus 3·70 (0·55-51·80) pg/mg; P = 0·195) or serum trypsinogen activating peptide level (1·10 (0·60-1·60) versus 0·45 (0-1·80) µg/l; P = 0·069). Intravital fluorescence microscopy revealed that anti-P-selectin antibody inhibited leucocyte rolling completely in postcapillary venules of the inflamed pancreas. CONCLUSION: Inhibition of P-selectin protected against pancreatic tissue injury in experimental pancreatitis. Targeting P-selectin may be an effective strategy to ameliorate inflammation in AP.

Role of neutrophils in the activation of trypsinogen in severe acute pancreatitis.

The relationship between inflammation and proteolytic activation in pancreatitis is an unresolved issue in pancreatology. The purpose of this study was to define the influence of neutrophils on trypsinogen activation in severe AP. Pancreatitis was induced by infusion of taurocholate into the pancreatic duct in C57BL/6 mice. For neutrophil depletion, an anti-Gr-1 antibody was administered before pancreatitis induction. Administration of the anti-Gr-1 antibody reduced circulating neutrophils by 97%. Pancreatic TAP and serum amylase levels increased 2 h and 24 h after induction of pancreatitis. Neutrophil depletion reduced pancreatic TAP and serum amylase levels at 24 h but not at 2 h after pancreatitis induction. Pancreatic MPO and infiltration of neutrophils, as well as MIP-2 levels, were increased 24 h after taurocholate infusion. Two hours after taurocholate administration, no significant pancreatic infiltration of neutrophils was observed. Injection of the anti-Gr-1 antibody abolished MPO activity, neutrophil accumulation, and MIP-2 levels, as well as acinar cell necrosis, hemorrhage, and edema in the pancreas at 24 h. Moreover, taurocholate-provoked tissue damage and MPO activity in the lung were normalized by neutrophil depletion. Intravital fluorescence microscopy revealed a 97% reduction of leukocytes in the pancreatic microcirculation after administration of the anti-Gr-1 antibody. Our data demonstrate that initial trypsinogen activation is independent of neutrophils, whereas later activation is dependent on neutrophils in the pancreas. Neutrophils are critical in mediating pancreatic and lung tissue damage in severe AP.

Melatonin protects against taurolithocholic-induced oxidative stress in rat liver.

Cholestasis, encountered in a variety of clinical disorders, is characterized by intracellular accumulation of toxic bile acids in the liver. Furthermore, oxidative stress plays an important role in the pathogenesis of bile acids. Taurolithocholic acid (TLC) was revealed in previous studies as the most pro-oxidative bile acid. Melatonin, a well-known antioxidant, is a safe and widely used therapeutic agent. Herein, we investigated the hepatoprotective role of melatonin on lipid and protein oxidation induced by TLC alone and in combination with FeCl(3) and ascorbic acid in rat liver homogenates and hepatic membranes. The lipid peroxidation products, malondialdehyde and 4-hydroxyalkenals (MDA + 4-HDA), and carbonyl levels were quantified as indices of oxidative damage to hepatic lipids and proteins, respectively. In the current study, the rise in MDA + 4-HDA levels induced by TLC was inhibited by melatonin in a concentration-dependent manner in both liver homogenates and in hepatic membranes. Melatonin also had protective effects against structural damage to proteins induced by TLC in membranes. These results suggest that the indoleamine melatonin may potentially act as a protective agent in the therapy of those diseases that involve bile acid toxicity.

Effects of carbon monoxide releasing molecule-liberated CO on severe acute pancreatitis in rats.

Recent studies have suggested that exogenously administered carbon monoxide (CO) is beneficial for resolution of acute inflammation. Severe acute pancreatitis (SAP) is an inflammatory condition which leads to a systemic inflammatory response syndrome (SIRS). In this study, we investigated the role of CO liberated from carbon monoxide releasing molecule-2 (CORM-2) in rats with SAP. SAP was induced by retrograde infusion of 5% sodium taurocholate into the pancreatobiliary duct. Forty Wistar rats were randomly divided into four groups. Sham group was given normal saline after the sham operation. SAP group was treated with normal saline after the induction of SAP. CORM-2 group was injected with CORM-2 (8 mg/kg, i.v.) after the onset of SAP. iCORM-2 group was given iCORM-2 (an inactive compound used as negative control) after SAP induction. All animals were sacrificed at 12h after the operation. Eighty rats (n=20 for each group) were monitored for 7days to observe their survival rates. In another set of experiments, the former three groups received the same treatment as mentioned above. The last group was given ZnPPIX (HO-1 inhibitor) by peritoneal injection at 1h before the administration of CORM-2 (n=10 for each group). Serum levels of amylase, tumor necrosis factor alpha (TNF-alpha), interleukin 1beta (IL-1beta), and interleukin 10 (IL-10) as well as myeloperoxidase (MPO) activity in pancreatic tissue were determined. Histological score, mRNA expression of these cytokines, heme oxygenase-1 (HO-1) expression, HO activity, and nuclear factor kappaB (NF-kappaB)-binding activity in the pancreas were also evaluated. Our results showed that compared with SAP group, CORM-2 treatment significantly reduced the serum levels of amylase, TNF-alpha, and IL-1beta, suppressed pancreatic tissue mRNA expression of TNF-alpha and IL-1beta, and decreased MPO activity in the pancreas. In contrast with the pro-inflammatory cytokines, the serum level and pancreatic tissue mRNA expression of IL-10 were markedly increased by the injection of CORM-2. The severity of pancreatic histology and survival rate were also significantly improved by the administration of CORM-2. Treatment with CORM-2 was associated with an increase in HO-1 expression at 12h after SAP induction. Pretreatment with ZnPPIX had no effect on the production and mRNA expression of these cytokines at 12h after the development of SAP with the treatment of CORM-2 as compared to CORM-2 group. Furthermore, CORM-2 treatment inhibited the activation of NF-kappaB in the pancreas. These results indicate that CORM-2-liberated CO exerts protective effects on SAP in rats, and the beneficial effects may be due to the suppression of NF-kappaB activation and subsequent regulation of NF-kappaB-dependent expression of cytokines.

Effects of etanercept on sodium taurocholate-induced acute pancreatitis in rats.

In this study, we examined the effects of etanercept (ETA) on experimentally induced pancreatitis. Acute pancreatitis was induced with Na taurocholate. ETA was simultaneously administered to treatment groups. Serum amylase and lipase activity, pancreatic histopathology, apoptosis, malondialdehyde (MDA), and myeloperoxidase enzyme activity (MPO) were assessed. Although rats in the groups 1, 2, and 3 were sacrificed 24h later, groups 4, 5, and 6 were sacrificed 5 days later. ETA treatment significantly decreased serum amylase activity (nontreated, 2636.16+/-191.94; treated, 1898.71+/-262.53; control, 506.28+/-17.31 U/L, P<0.001), lipase activity (nontreated, 3049.67+/-972.65; treated, 2538.85+/-660.45; control, 88.57+/-7.54 U/L, P<0.001), histopathologic score (nontreated, 5.43+/-0.43; treated, 2.57+/-0.20; control, 0.71+/-0.18, P<0.001), MDA (nontreated, 105.77+/-13.29; treated, 92.89+/-10.39; control, 41.26+/-2.54 nmol/g, P<0.001), and MPO (nontreated, 0.64+/-1.15; treated, 0.59+/-0.13; control, 0.17+/-0.02 units/g/wet weight, P<0.001) activity in 24-h groups. In 5-day groups, ETA treatment decreased amylase activity (nontreated, 738.67+/-48.60; treated, 497.14+/-47.25; control, 389.00+/-9.17 U/L, P<0.001), lipase activity (nontreated, 101.33+/-39.32; treated, 34.57+/-7.29; control, 23.42+/-2.12 U/L, P<0.001), histopathologic score (nontreated, 5.43+/-0.43; treated, 3.71+/-0.68; control, 0.00+/-0.00, P<0.001), MDA (nontreated, 67.91+/-4.28; treated, 60.91+/-3.57; control, 14.85+/-1.16 nmol/g, P<0.001), and MPO (nontreated, 0.36+/-0.04; treated, 0.27+/-0.02; control, 0.14+/-0.02 units/g/wet weight, P<0.001) activity. Caspase-positive cells numbers around the necrosis significantly decreased by ETA treatment in both 24-h groups (nontreated, 74.28+/-3.26; treated, 67.00+/-1.15; control, 3.85+/-0.63, P<0.001) and 5-day groups (nontreated, 79.85+/-3.01; treated, 47.85+/-5.76; control, 2.22+/-0.63, P<0.001). These results showed that ETA has an ameliorating effect on sodium taurocholate-induced acute necrotic pancreatitis.

Does the 3-aminobenzamide effect on bacterial translocation affect experimental acute necrotizing pancreatitis?

BACKGROUND/AIMS: One of the most important complications of acute pancreatitis is the secondary bacterial infections of the pancreas and gut. Translocation of bacteria from the gut is accepted as being responsible for the development of septic complications in acute pancreatitis. In this study, our aim was to investigate the effect of PARP inhibition via 3-aminobenzamide on the bacterial translocation in acute pancreatitis. METHODS: 45 male Sprague-Dawley rats were randomly allocated into three groups. Group I (Sham+saline) received normal saline infusion into the common biliopancreatic duct. Acute pancreatitis was induced in Group II (acute pancreatitis+saline) and Group III (acute pancreatitis+ 3-aminobenzamide) by the retrograde injection of taurocholate into the common biliopancreatic duct. Six hours after induction of pancreatitis, the rats in Group I and II were treated with saline (1 ml, every 12 hours), while the rats in Group III were treated with 3-aminobenzamide (10 mg/kg/day every 12 hours), intraperitoneally. In the 54th hour of the study, blood and tissue samples were taken for biochemical, microbiological and histopathological analysis. RESULTS: Acute pancreatitis developed in Groups II and III. Pathologic score [median (25-75% percentiles)] of the pancreatitis in Group III [8 (7-9)] was significantly lower than in Group II [19 (18-21)] (p<0.001). Bacterial translocation to mesenteric lymph node (53.3%), peritoneum (60%) and pancreas (46.7%) in Group III was significantly lower than in Group II (100% for all) (p<0.02, p<0.03, p<0.005, respectively). Pancreatic tissue glutathione peroxidase, superoxide dismutase, and malondialdehyde levels were better in Group III compared to Group II (p<0.001 for all). Comparison of Groups II and III demonstrated reduced severity of inflammation of the gut in Group III (p>0.05). Improvement in bacterial translocation was correlated with reducing oxidative stress. CONCLUSIONS: We demonstrated that 3-aminobenzamide therapy improved histopathologic score and oxidative stress in experimental pancreatitis. In addition, it was demonstrated microbiologically and histopathologically that 3-aminobenzamide therapy improves bacterial translocation. Further survival studies demonstrating the efficacy of 3-aminobenzamide therapy and explaining the potential mechanisms of bacterial translocation prevention in acute necrotizing pancreatitis will be beneficial.

Taurodeoxycholate-induced intestinal injury is modulated by oxidative stress-dependent pre-conditioning like mechanisms.

Mechanisms by which hydrophobic bile salts cause tissue changes below their critical micellar concentration (CMC, 1-2mM) and above (4-8mM) remain poorly understood. In this study, rat colonic mucosa was exposed to different concentrations of taurodeoxycholate (TDC), t-butyl-hydroperoxide (t-BH) or glutathione ester with or without pre-incubation with 2mM TDC. Exposure to 2mM TDC was associated with 10% higher tissue levels of total glutathione (GSH, basal values: 33.7+/-3.3 nmol/mg prot). With TDC 8mM, GSH decreased to 16.4+/-2.3 nmol/mg prot (P<0.05), oxidized glutathione (GSSG) increased by 60% (P<0.05), glutathione peroxidase (GSH-Px) and reductase activities were threefold increased, protein carbonyls fourfold increased, protein sulfhydrils decreased by 78%, lactate dehydrogenase (LDH) and GSSG release in the incubation medium were sixfold higher. In 2mM TDC pre-treated tissues, the subsequent incubation with 8mM TDC induced a lower loss of tissue GSH, and a lower release of LDH and GSSG. Pre-incubation with 2mM TDC partly protected against t-BH toxicity, while glutathione ester protected against 8mM TDC toxicity. In conclusion, TDC exposure causes opposite effects depending on CMC: induction of antioxidant protective systems including glutathione system (pre-conditioning effect) was observed with TDC below CMC, oxidative damages pointing to decreased mucosal detoxification potential with above CMC.

Metabolism and pharmacokinetics of genipin and geniposide in rats.

Geniposide, an iridoid glucoside, is a major constituent in the fruits of Gardenia jasminoides (Gardenia fruits), a popular Chinese herb. Genipin, the aglycone of geniposide, is used to prepare blue colorants in food industry and also a crosslinking reagent for biological tissue fixation. In this study, we investigated the metabolism and pharmacokinetics of genipin and geniposide in rats. Blood samples were withdrawn via cardiopuncture and the plasma samples were assayed by HPLC method before and after hydrolysis with sulfatase and beta-glucuronidase. The results indicated that after oral administration of genipin or Gardenia fruit decoction, genipin sulfate was a major metabolite in the bloodstream, whereas the parent forms of genipin and geniposide were not detected. Importantly, oral administration of 200mg/kg of genipin resulted in a mortality of 78% (7/9) in rats.

PF2401-SF, standardized fraction of Salvia miltiorrhiza and its constituents, tanshinone I, tanshinone IIA, and cryptotanshinone, protect primary cultured rat hepatocytes from bile acid-induced apoptosis by inhibiting JNK phosphorylation.

Bile acid-induced hepatocyte apoptosis plays an important role in cholestatic liver disease, and the role of apoptosis may be of therapeutic interest in preventing liver disease. The dried root of Salvia miltiorrhiza Bunge (Labiatae) has been used traditionally to treat liver diseases. We investigated the antiapoptotic effects of a standardized fraction of S. miltiorrhiza (PF2401-SF) and its components, tanshinone I, tanshinone IIA, and cryptotanshinone, in primary cultured rat hepatocytes. PF2401-SF was enriched with tanshinone I (11.5%), tanshinone IIA (41.0%), and cryptotanshinone (19.1%). Glycochenodeoxycholic acid (GCDC)-induced apoptosis, as shown by DNA fragmentation, poly(ADP-ribose) polymerase cleavage, and activation of caspases-8, -9, and -3. PF2401-SF and its components, tanshinone I, tanshinone IIA, and cryptotanshinone showed antiapoptotic activity. Treatment with PF2401-SF or with its components significantly inhibited the generation of intracellular reactive oxygen species. Hydrophobic bile acids activate c-Jun-NH(2)-terminal kinase (JNK), p38 mitogen-activated protein kinases (MAPK), and extracellular signal-regulated kinase 1/2, and PF2401-SF inhibited the phosphorylation of JNK and p38. All three components of PF2401-SF inhibited JNK phosphorylation. Addition of inhibitors of MAPK showed that inhibition of JNK decreased apoptosis. These data indicate that PF2401-SF and its components protect hepatocytes from GCDC-induced apoptosis in vitro by inhibiting JNK.

Effects of bile acids on biliary epithelial cell proliferation and portal fibroblast activation using rat liver slices.

During cholestasis, bile acids accumulate in the liver, and induce cellular alterations. Cholestasis is a major cause of liver fibrosis. We have used precision-cut liver slices (PCLS) in culture to investigate the effects of bile acids on hepatic cells. Rat PCLS were placed on an insert in a vial containing culture medium, and gently agitated on a roller platform. PCLS were treated with 100 microM taurolithocholate (TLC), taurodeoxycholate (TDC) or taurocholate (TC) for 24 or 48 h. PCLS viability was measured, and immunohistochemistry was performed with antibodies against active caspase 3, platelet-derived growth factor (PDGF) receptor-beta and ED-A fibronectin. TDC and TLC, two hydrophobic bile acids, induced hepatocyte necrosis and apoptosis, whereas TC, an hydrophilic bile acid, improved slice viability as compared with controls. Both TDC and TC induced biliary epithelial cell proliferation, together with portal fibroblast proliferation and activation, as shown by PDGF receptor-beta and ED-A fibronectin expression. TLC induced biliary epithelial cell apoptosis. Our results indicate that individual bile acids induce cell type-specific effects in a complex liver microenvironment. The fact that PCLS support biliary epithelial cell and portal fibroblast proliferation will make this model very useful for the study of the mechanisms involved in portal fibrosis.

An experimental study of choleretic effect and histopathologic alterations in the gastrointestinal system after whole-bowel irrigation.

BACKGROUND/PURPOSE: Whole-bowel irrigation (WBI) has been used for different purposes. It has been the preferred method of bowel cleansing before large bowel surgery and colonoscopy. There are some studies about histopathologic alterations in the gastrointestinal system caused by WBI. It was reported that large quantities of bile-stained intraluminal fluid were seen after WBI with lactated Ringer's solution. In light of all these studies, the authors have decided to inspect whether WBI is choleretic and whether the histopathologic findings in the gastrointestinal system are caused by this choleretic effect. METHODS: During the experimental procedures, animals at first were divided into 2 major groups of A and B; A consisted of the animals whose bile was not collected, and B consisted of animals whose bile was collected. Later, these 2 groups were divided into 4 subgroups consisting of 6 animals each. Sham operations were performed on the animals in group SH-A and SH-B. The animals in group saline-A and saline-B were given 0.9% of sodium chloride (isotonic sodium chloride). The animals in group LR-A and LR-B received lactated Ringer's solution. The last group (PEG-A and PEG-B) underwent WBI by using polyethylene glycol solution (PEG). After completing WBI, animals were rested for 4 hours, and at the end of resting time, laparotomy was performed to take biopsy specimens from stomach, small bowel, and large bowel. All of the specimens were evaluated and graded for congestion, edema, and inflammation by the individual blinded pathologist. RESULTS: According to the results, WBI has been shown to affect biliary secretion and to have a choleretic effect (P <.05, Tuckey-Kramer). The choleretic effect has also been shown to be responsible for histopathologic alterations in some groups (P <.05, Tuckey-Kramer). The most severe changes of congestion, edema, and inflammation have been detected in isotonic sodium chloride solutions in all groups. The least alterations have been seen in lactated Ringer's and PEG solutions. CONCLUSIONS: In light of these findings, it might be concluded that the use of WBI can cause different degrees of histopathologic changes in gastrointestinal system depending on the type of solutions. WBI has been shown to have choleretic effect, and it was found that there is a connection between histopathologic changes in gastrointestinal system and choleretic effect of WBI.