Hepatic Inflammatory Mediators Research Articles

Enhancing hepatoprotective action: oxyberberine amorphous solid dispersion system targeting TLR4

Oxyberberine (OBB) is a significant natural compound, with excellent hepatoprotective properties. However, the poor water solubility of OBB hinders its release and absorption thus resulting in low bioavailability. To overcome these drawbacks of OBB, amorphous spray-dried powders (ASDs) of OBB were formulated. The dissolution, characterizations, and pharmacokinetics of OBB-ASDs formulation were investigated, and its hepatoprotective action was disquisitive in the D-GalN/LPS-induced acute liver injury (ALI) mouse model. The characterizations of OBB-ASDs indicated that the crystalline form of OBB active pharmaceutical ingredients (API) was changed into an amorphous form in OBB-ASDs. More importantly, OBB-ASDs showed a higher bioavailability than OBB API. In addition, OBB-ASDs treatment restored abnormal histopathological changes, improved liver functions, and relieved hepatic inflammatory mediators and oxidative stress in ALI mice. The spray drying techniques produced an amorphous form of OBB, which could significantly enhance the bioavailability and exhibit excellent hepatoprotective effects, indicating that the OBB-ASDs can exhibit further potential in hepatoprotective drug delivery systems. Our results provide guidance for improving the bioavailability and pharmacological activities of other compounds, especially insoluble natural compounds. Meanwhile, the successful development of OBB-ASDs could shed new light on the research process of poorly soluble medicine.

Melissa officinalis extract palliates redox imbalance and inflammation associated with hyperthyroidism-induced liver damage by regulating Nrf-2/ Keap-1 gene expression in γ-irradiated rats

BackgroundMelissa officinalis (MO) is a well-known medicinal plant species used in the treatment of several diseases; it is widely used as a vegetable, adding flavour to dishes. This study was designed to evaluate the therapeutic effect of MO Extract against hyperthyroidism induced by Eltroxin and γ-radiation.MethodsHyperthyroidism was induced by injecting rats with Eltroxin (100 µg/kg/ day) for 14 days and exposure to γ-radiation (IR) (5 Gy single dose). The hyperthyroid rats were orally treated with MO extract (75 mg/kg/day) at the beginning of the second week of the Eltroxin injection and continued for another week. The levels of thyroid hormones, liver enzymes and proteins besides the impaired hepatic redox status and antioxidant parameters were measured using commercial kits. The hepatic gene expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its inhibitor Kelch-like ECH-associated protein-1(Keap-1) in addition to hepatic inflammatory mediators including tumor necrosis factor-α (TNF- α), Monocyte chemoattractant protein-1 (MCP-1) and fibrogenic markers such as transforming growth factor-beta1 (TGF-β1) were determined.ResultsMO Extract reversed the effect of Eltroxin + IR on rats and attenuated the thyroid hormones. Moreover, it alleviated hyperthyroidism-induced hepatic damage by inhibiting the hepatic enzymes’ activities as well as enhancing the production of proteins concomitant with improving cellular redox homeostasis by attenuating the deranged redox balance and modulating the Nrf2/Keap-1 pathway. Additionally, MO Extract alleviated the inflammatory response by suppressing the TNF- α and MCP-1 and prevented hepatic fibrosis via Nrf2-mediated inhibition of the TGF-β1/Smad pathway.ConclusionAccordingly, these results might strengthen the hepatoprotective effect of MO Extract in a rat model of hyperthyroidism by regulating the Nrf-2/ Keap-1 pathway.

The hepatotoxicity of γ-radiation synthesized 5-fluorouracil nanogel versus 5-fluorouracil in rats model.

The clinical use of 5-fluorouracil (5-FU), a routinely used chemotherapy medication, has a deleterious impact on the liver. Therefore, it is necessary to find a less harmful alternative to minimize liver damage. This study was designed to see how 5-fluorouracil nanogel influenced 5-FU-induced liver damage in rats. To induce liver damage, male albino rats were injected intraperitoneally with 5-FU (12.5mg/kg) three doses/week for 1month. The histopathological examination together with measuring the activities of serum alanine and aspartate aminotransferase enzymes (ALT and AST) were used to evaluate the severity of liver damage besides, hepatic oxidative stress and antioxidant markers were also measured. The hepatic gene expression of heme oxygenase-1 (HO-1), nuclear factor erythroid 2-related factor 2 (Nrf2) and its inhibitor Kelch-like ECH-associated protein-1(Keap-1) in addition to hepatic inflammatory mediators including tumor necrosis factor-α (TNF- α) and interleukins (IL-1β, IL-6) were detected. 5-Fu nanogel effectively attenuated 5-FU-induced liver injury by improving the hepatic structure and function (ALT and AST) besides the suppression of the hepatic inflammatory mediators (TNF- α, IL-1β and IL-6). Additionally, 5-FU nanogel alleviated the impaired redox status and restored the antioxidant system via maintaining the cellular homeostasis Keap-1/Nrf2/HO-1 pathway. Consequently, 5-Fu nanogel exhibited lower liver toxicity compared to 5-FU, likely due to the alleviation of hepatic inflammation and the regulation of the cellular redox pathway.

Persea americana attenuates inflammatory response associated with hyperlipidemia in ovariectomized and irradiated rats by regulating MMP-3/TIMP-1 levels

Objective: To explore the effect of Persea americana supplementation on inflammation, oxidative stress, and lipid profiles in ovariectomized rats fed with a high-fat diet and exposed to radiation. Methods: The control group was sham operated, while groups 2-5 were ovariectomized and fed a high-fat diet. Groups 4 and 5 were exposed to γ-radiation (1 Gy/week for 5 weeks) after ovariectomy. Groups 3 and 5 were treated with 1 mL/250 g/day of Persea americana for one month. Serum levels of estrogen, alanine aminotransferase, aspartate aminotransferase, cholesterol, triglycerides and lipoproteins were measured. Additionally, hepatic oxidative stress, inflammatory and fibrogenic markers were evaluated. Results: Persea americana treatment reduced the oxidative stress markers as well as the levels of triglyceride, total cholesterol, and low-density lipoprotein cholesterol, which in turn lowered hepatic fat accumulation. Moreover, it suppressed hepatic inflammatory mediators (interleukin-6, tumor necrosis factor-α, and C-reactive protein) and downregulated pro-fibrogenic markers (transforming growth factor-β and tissue inhibitor of metalloproteinase-1). Conclusions: Persea americana provides protection against ovariectomy, and gamma radiation-mediated hepatic inflammation not only through its antioxidant, anti-inflammatory, lipid-lowering effect but also by modulating the fibrogenic markers.

Effect of Systemic Triphenylphosphonium on Organ Function and Oxidative Stress

Conditions of systemic stress can lead to increased reactive oxygen species production, mitochondrial dysfunction, systemic inflammation, and multiorgan dysfunction. Triphenylphosphonium (TPP+) is a lipophilic cation used to target therapeutics to mitochondria. We sought to determine the effects of TPP+ on mitochondrial integrity. Male rats were anesthetized and TPP+ (5 mg/kg) or vehicle (saline) was administered intravenously 30-minutes after anesthesia initiation and intraperitoneally (20 mg/kg) 60-minutes later. Rats were exsanguinated 2-hours postinjection. Cardiac, pulmonary, hepatic, splenic, and renal tissues were analyzed for inflammation, lipid peroxidation, endogenous antioxidant activity, cytokine expression, and mitochondrial function. In vitro modeling was performed using freshly isolated hepatocytes subjected to 8-hours hypoxia/30-minutes reoxygenation in the absence or presence of TPP+. TPP+ increased lipid peroxidation in the liver, lung, and kidney as well as antioxidant activity in the liver, kidney, and spleen. Conversely, antioxidant activity decreased in the lung with TPP+. In addition, TPP+ altered hepatic inflammatory mediators. In vitro, TPP+ attenuated oxygen consumption and, when combined with hypoxic injury, depolarized mitochondrial membranes in hepatocytes. TPP+ induces systemic responses associated with oxidative stress and worsening pathologies in animals. Caution should be exercised when employing TPP+ for therapeutics.

Nobiletin attenuates lipopolysaccharide/D‑galactosamine‑induced liver injury in mice by activating the Nrf2 antioxidant pathway and subsequently inhibiting NF‑κB‑mediated cytokine production.

Inflammation and oxidative stress serve an important role in the development of lipopolysaccharide/D-galactosamine (LPS/GalN)‑induced acute liver injury. Nobiletin, which is found in high quantities in the peel of citrus fruits, is able to modulate immune responses, including inflammatory response and oxidative stress. The present study aimed to evaluate the protective effects of nobiletin on LPS/GalN‑induced acute liver injury. Male C57BL/6 mice were intraperitoneally treated with nobiletin (50, 100 and 200mg/kg) 2h prior to LPS/GalN injection. Liver injury was observed in the LPS/GalN group, as demonstrated by increased levels of serum hepatic enzymes and hepatic inflammatory mediators, as well as by histopathological alterations. Treatment with nobiletin reduced serum alanine aminotransferase and aspartate aminotransferase levels, improved hepatic structure, and suppressed hepatic interleukin (IL)‑1β, IL‑6 and tumor necrosis factor‑α production 24h after LPS/GalN exposure. Western blot analysis revealed that nobiletin treatment inhibited inducible nitric oxide synthase and cyclooxygenase‑2 liver expression. In addition, nobiletin suppressed LPS/GalN‑induced phosphorylation and degradation of inhibitor of nuclear factor (NF)‑κB (IκB)α, as well as NF‑κB p65 translocation into the nucleus. Nobiletin also upregulated the expression of nuclear NF‑E2‑related factor2 (Nrf2) and cytoplasmic heme oxygenase‑1. In conclusion, these results indicate that nobiletin serves a protective role in LPS/GalN‑induced acute liver injury via activation of the Nrf2 antioxidant pathway and subsequent inhibition of NF‑κB‑mediated cytokine production. These findings support the potential for nobiletin as a therapeutic agent for the treatment of acute liver injury.

The Thyroid Hormone Receptors Inhibit Hepatic Interleukin-6 Signaling During Endotoxemia.

Decreased thyroidal hormone production is found during lipopolysaccharide (LPS)-induced endotoxic shock in animals as well as in critically ill patients. Here we studied the role of the thyroid hormone receptors (TRs) in activation of STAT3, NF-κB and ERK, which play a key role in the response to inflammatory cytokines during sepsis. TR knockout mice showed down-regulation of hepatic inflammatory mediators, including interleukin 6 (IL-6) in response to LPS. Paradoxically, STAT3 and ERK activity were higher, suggesting that TRs could act as endogenous repressors of these pathways. Furthermore, hyperthyroidism increased cytokine production and mortality in response to LPS, despite decreasing hepatic STAT3 and ERK activity. This suggested that TRs could directly repress the response of the cells to inflammatory mediators. Indeed, we found that the thyroid hormone T3 suppresses IL-6 signalling in macrophages and hepatocarcinoma cells, inhibiting STAT3 activation. Consequently, the hormone strongly antagonizes IL-6-stimulated gene transcription, reducing STAT3 recruitment and histone acetylation at IL-6 target promoters. In conclusion, TRs are potent regulators of inflammatory responses and immune homeostasis during sepsis. Reduced responses to IL-6 should serve as a negative feedback mechanism for preventing deleterious effects of excessive hormone signaling during infections.

Hepatoprotective Effects of Rubus idaeus L. Leaves against CCl4-Induced Liver Injury via Antioxidant, Anti-inflammatory and Antiapoptotic Mechanisms

Aims: To investigate the hepatoprotective effects of red raspberry (Rubus idaeus L.) leaves against oxidative stress, inflammation and apoptosis induced by carbon tetrachloride (CCl4) in rats. Study Design and Methodology: Forty rats were divided into 5 groups, 1) normal control; 2) Raspberry (Rsp) control (100 mg/kg); 3) CCl4 control; 4) and 5) CCl4 groups pre-treated with 50 and 100 mg/kg of Rsp leaves, respectively, once daily for 10 days. Liver injury was induced on the 11th day in groups 3, 4 and 5 by intraperitoneal injection of CCl4 (1.0 ml/kg) in 50% olive oil (1:1). Serum and liver were separated and prepared for biochemical and histological assay. Antioxidant, inflammatory and apoptotic markers were evaluated. Results: CCl4-induced liver damage was manifested by increased activities of serum marker enzymes, elevated levels of lipid peroxidation and by decreased hepatic antioxidants including reduced glutathione, glutathione peroxidase, superoxide dismutase and catalase. CCl4 also resulted in elevated levels of hepatic inflammatory mediators including tumor necrosis factor-α (TNFα), interleukin -6 (IL-6), IL-1β and nitric oxide (NO) as well as upregulation of apoptotic markers including caspase-3, FasL and Bax. Hepatic levels of Bcl2, an anti-apoptotic factor, was Original Research Article Attia; EJMP, 14(1): 1-16, 2016; Article no.EJMP.25300 2 decreased by CCl4. Pretreatment with Rsp leaves significantly ameliorated the elevation in serum liver enzymes and prevented lipid peroxidation and the depletion of the antioxidants. In addition, Rsp leaves exhibited anti-inflammatory effects via attenuation of increased hepatic levels of TNF-α, Il-6, IL-1β and NO. Additionally, CCl4-Induced apoptosis in the liver cell was attenuated by Rsp pretreatment. With regard to histological examination, Rsp leaves significantly alleviated degeneration and necrosis of hepatocytes, accompanied by decreased inflammatory cell infiltration. Conclusion: These results suggest that Rsp leaves have protective effects against CCl4-induced acute liver injury, and this protection is likely due to antioxidant, anti-inflammatory and antiapoptotic mechanisms.

The Protective Effect of Huperzine A Against Hepatic Ischemia Reperfusion Injury in Mice

BackgroundNowadays, hepatic ischemia reperfusion (HI/R) injury is regarded as a serious concern in clinical practices. Huperzine A (HupA) is an alkaloid isolated from the Chinese folk medicine huperzia serrate, which has possessed diverse pharmacological actions. MethodsA mouse model of HI/R was caused by clamping the hepatic artery, the hepatoportal vein, and the bile duct with a vascular clamp for 30 minutes followed by reperfusion for 6 hours under anesthesia. The sham group experienced the identical procedure without hepatic ischemia. The HupA group received an injection into the tail vein 5 minutes prior to HI/R at the doses of 167 and 500 μg/kg. The vehicle group was injected with physiological saline instead of HupA. The liver function was assessed by determinations of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. Tissue levels of superoxide dismutase (SOD), catalase (CAT), malondiadehyde (MDA), and glutathione (GSH) were also measured spectrophotometrically. In addition, the activities of hepatic inflammatory mediators such as nuclear factor kappa B (NF-κB) p65, tumor necrosis factors-α (TNF-α, interleukin-1β (IL-1β) and IL-6 were also measured. Furthermore, the apoptotic damage was evaluated by measuring caspase-3 activity in hepatic tissues. ResultsTreatment with HupA in mice at the doses of 167 and 500 μg/kg remarkably reduced serum ALT and AST activities in HupA-treated ischemic mice. Furthermore, HupA treatment could enhance the activities of hepatic tissue SOD, CAT, and GSH but decrease MDA tissue content. The activities of inflammatory cytokines including NF-κB p65, TNF-α, IL-1β and IL-6 were all decreased in ischemic mice treated with HupA. Colorimetric test results illustrated that a marked reduction of caspase-3 activity was found in the HupA-treated group compared with the vehicle group. ConclusionOur present data suggest that HupA has a protective role against HI/R injury of mice and antioxidative, anti-inflammatory, and antiapoptotic actions are involved in its protection.

EARLY GROWTH RESPONSE 1 MEDIATES THE SYSTEMIC AND HEPATIC INFLAMMATORY RESPONSE INITIATED BY HEMORRHAGIC SHOCK

Hemorrhagic shock (HS) is a major cause of morbidity and mortality in trauma patients. The early growth response 1 (Egr-1) transcription factor is induced by a variety of cellular stresses, including hypoxia, and may function as a master switch to trigger the expression of numerous key inflammatory mediators. We hypothesized that HS would induce hepatic expression of Egr-1 and that Egr-1 upregulates the inflammatory response after HS. The Egr-1 mice and wild-type (WT) controls (n>or=5 for all groups) were subjected to HS alone or HS followed by resuscitation (HS/R). Other mice were subjected to a sham procedure which included general anesthesia and vessel cannulation but no shock (sham). After the HS, HS/R, or sham procedures, mice were euthanized for determination of serum concentrations of interleukin (IL) 6, IL-10, and alanine aminotransferase. Northern blot analysis was performed to evaluate Egr-1 messenger RNA (mRNA) expression. Liver whole cell lysates were evaluated for Egr-1 protein expression by Western blot analysis. Hepatic expression of IL-6, granulocyte colony-stimulating factor, and intracellular adhesion molecule 1 mRNA was determined by semiquantitative reverse transcriptase-polymerase chain reaction. The Egr-1 DNA binding was assessed using the electrophoretic mobility shift assay. Hemorrhagic shock results in a rapid and transient hepatic expression of Egr-1 mRNA in WT mice by 1 h, whereas protein and DNA binding activity was evident by 2.5 h. The Egr-1 mRNA expression diminished after 4 h of resuscitation, whereas Egr-1 protein expression and DNA binding activity persisted through resuscitation. The Egr-1 mice exhibited decreased levels of hepatic inflammatory mediators compared with WT controls with a decrease in hepatic mRNA levels of IL-6 by 42%, granulocyte colony-stimulating factor by 39%, and intracellular adhesion molecule 1 by 43%. Similarly, Egr-1 mice demonstrated a decreased systemic inflammatory response and hepatic injury after HS/R compared with their WT counterparts. Early growth response 1 is rapidly upregulated in the liver during and after resuscitation from HS. Our results showing a blunted inflammatory response in Egr-1 mice provides evidence that Egr-1 functions as a proximal signal transduction mechanism responding to shock by amplifying the systemic inflammatory response.

Effects of hydroxyethyl starch on hepatic production of cytokines and activation of transcription factors in lipopolysaccharide‐administered rats

Hydroxyethyl starch (HES) is one of the most frequently used plasma substitutes. Some studies have indicated that HES may have anti-inflammatory effects. The present in vivo study was performed to investigate the effects of HES on hepatic production of cytokines and activation of transcription factors in sepsis. Adult male Sprague-Dawley rats were randomly divided into four groups: rats challenged with lipopolysaccharide (LPS) (5 mg kg(-1)) and treated with saline (64 ml kg(-1)); challenged with LPS (5 mg kg(-1)) and treated with HES (16 ml kg(-1)); injected with saline and treated with HES (16 ml kg(-1)); and saline control. Each hepatic tissue was collected in groups of rats 2 h after induction of endotoxemia for determination of tumour necrosis factor (TNF)-alpha levels, TNF-alpha mRNA expressions, and nuclear factor (NF)-kappaB, activator protein (AP)-1 activities or 3 h after LPS challenge for IL-1beta, IL-6, IL-8, IL-10 levels and the mRNA expressions. Endotoxemia was associated with significant increases in hepatic proinflammatory cytokine productions and transcription factor activities. HES significantly reduced the increased hepatic levels of TNF-alpha, IL-1beta, IL-6, IL-8 and the mRNAs in the endotoxemic rats. Similarly, HES could inhibit hepatic NF-kappaB and AP-1 activations. The results suggest that in sepsis HES may down-regulate hepatic inflammatory mediators production and these anti-inflammatory effects may act through inhibition of NF-kappaB and AP-1 activations.