Melatonin prevents hemorrhagic shock-induced liver injury in rats through an Akt-dependent HO-1 pathway

Carbon Dots Derived from Traditional Chinese Medicines with Bioactivities: A Rising Star in Clinical Treatment

In the field of carbon nanomaterials, carbon dots (CDs) have become a preferable choice in biomedical applications. Based on the concept of green chemistry, CDs derived from traditional Chinese medicines (TCMs) have attracted extensive attention, including TCM charcoal drugs, TCM extracts, and TCM small molecules. The design and preparation of CDs from TCMs (TCMs-CDs) can improve the inherent characteristics of TCMs, such as solubility, particle size distribution, and so on. Compared with other precursor materials, TCMs-CDs have outstanding intrinsic bioactivities and potential pharmacological effects. However, the research of TCMs-CDs in biomedicine is not comprehensive, and their mechanisms have not been understood deeply either. In this review, we will provide concise insights into the recent development of TCMs-CDs, with a major focus on their preparation, formation, precursors, and bioactivities. Then we will discuss the perfect transformation from TCMs to TCMs-CDs. Finally, we discuss the opportunities and challenges for the application of TCMs-CDs in clinical treatment.

Effects of melatonin on intestinal function and bacterial compositions in sucking piglets

Melatonin has been reported to affect intestinal function by targeting microbiome, morphological structure, barrier integrity and nutrient absorptive system. While the effect of melatonin on intestinal development in newborn infants is obscure, thus, this study firstly attempted to investigate the hypothesis that melatonin treatment improves intestinal development in sucking piglets. 14 healthy newborn piglets received 10 ml melatonin solution (1 mg/ml) or drinking water (n = 7) for 21 days. The results showed that oral administration of melatonin increased liver relative weight (p < 0.05) but failed to affect growth performance in sucking piglets (p > 0.05). Immunostaining jejunal samples from melatonin group showed high expressions of nnos and claudin1, indicating that melatonin improved intestinal neural development and barrier integrity. Also, melatonin promoted intestinal absorptive function evidenced by the increased serum proline concentration in melatonin-treated piglets compared with the control (p < 0.05). Gut microbiota compositions were tested by 16S rDNA sequencing and the results showed that melatonin increased the relative abundance of Actinobacteria compared with the control (p < 0.05) at the phylum level. However, Selenomonadales was markedly reduced compared with the control at the order level (p < 0.05). Gut and faecal volatile fatty acids were tested to evaluate the microbiota metabolism, but no difference was noticed in volatile fatty acid concentrations (p > 0.05). Melatonin improved intestinal development by affecting neural development, barrier integrity, nutrient absorption and microbiota in sucking piglets.

Chinese Medicinal Herb-Derived Carbon Dots for Common Diseases: Efficacies and Potential Mechanisms

The management of hemorrhagic diseases and other commonly refractory diseases (including gout, inflammatory diseases, cancer, pain of various forms and causes) are very challenging in clinical practice. Charcoal medicine is a frequently used complementary and alternative drug therapy for hemorrhagic diseases. However, studies (other than those assessing effects on hemostasis) on charcoal-processed medicines are limited. Carbon dots (CDs) are quasi-spherical nanoparticles that are biocompatible and have high stability, low toxicity, unique optical properties. Currently, there are various studies carried out to evaluate their efficacy and safety. The exploration of using traditional Chinese medicine (TCM) -based CDs for the treatment of common diseases has received great attention. This review summarizes the literatures on medicinal herbs-derived CDs for the treatment of the difficult-to-treat diseases, and explored the possible mechanisms involved in the process of treatment.

Carbon Monoxide Releasing Molecule-3 Enhances Heme Oxygenase-1 Induction via ROS-Dependent FoxO1 and Nrf2 in Brain Astrocytes

Carbon monoxide releasing molecule-3 (CORM-3) has been shown to protect inflammatory diseases via the upregulation of heme oxygenases-1 (HO-1). However, in rat brain astrocytes (RBA-1), the mechanisms underlying CORM-3-induced HO-1 remain poorly defined. This study used western blot, real-time PCR, and promoter activity assays to determine the levels of HO-1 expression and 2',7'-dichlorodihydrofluorescein diacetate (H₂DCFDA) and dihydroethidium (DHE) to measure reactive oxygen species (ROS). We found that CORM-3-induced HO-1 expression was mediated through ROS generation by Nox or mitochondria. The signaling components were differentiated by pharmacological inhibitors and small interfering RNA (siRNA). Subcellular fractions, immunofluorescent staining, and chromatin immunoprecipitation assay were used to evaluate the nuclear translocation and promoter binding activity of Nrf2 induced by CORM-3. The roles of mTOR and FoxO1 in CORM-3-stimulated responses are still unknown in RBA-1 cells. Our results demonstrated that transfection with siRNAs or pretreatment with pharmacological inhibitors attenuated the levels of HO-1 and phosphorylation of signaling components including Akt, mTOR, FoxO1, and Nrf2 stimulated by CORM-3. Moreover, pretreatment with N-acetyl-L-cysteine, diphenyleneiodonium chloride, apocynin, or rotenone blocked nuclear translocation and promoter binding activity of Nrf2 induced by CORM-3. The present study concluded that in RBA-1 cells, CORM-3-induced HO-1 expression is, at least partially, mediated through Nox and mitochondria/ROS-dependent PI3K/Akt/mTOR cascade to activate FoxO1 or ROS leading to activation of Nrf2 activity.

Hibernation-Based Approaches in the Treatment of Hemorrhagic Shock

Hemorrhagic shock is the leading cause of preventable death after trauma. Hibernation-based treatment approaches have been of increasing interest for various biomedical applications. Owing to apparent similarities in tissue perfusion and metabolic activity between severe blood loss and the hibernating state, hibernation-based approaches have also emerged for the treatment of hemorrhagic shock. Research has shown that hibernators are protected from shock-induced injury and inflammation. Utilizing the adaptive mechanisms that prevent injury in these animals may help alleviate the detrimental effects of hemorrhagic shock in non-hibernating species. This review describes hibernation-based preclinical and clinical approaches for the treatment of severe blood loss. Treatments include the delta opioid receptor agonist D-Ala-Leu-enkephalin (DADLE), the gasotransmitter hydrogen sulfide, combinations of adenosine, lidocaine, and magnesium (ALM) or D-beta-hydroxybutyrate and melatonin (BHB/M), and therapeutic hypothermia. While we focus on hemorrhagic shock, many of the described treatments may be used in other situations of hypoxia or ischemia/reperfusion injury.

Hemostatic and hepatoprotective bioactivity of Junci Medulla Carbonisata-derived Carbon Dots

AIM

To explore the hemostatic and hepatoprotective bioactivity of Junci Medulla Carbonisata-derived Carbon Dots (JMC-CDs).

MATERIALS & METHODS

The JMC-CDs were characterized using transmission electron microscopy, HPLC, Fourier transform IR, UV, fluorescence and x-ray photoelectron spectroscopy. The hemostatic effect of JMC-CDs was evaluated and confirmed by trauma hemorrhagic animal models and internal hemorrhage animal model induced by Deinagkistrodon acutus venom.

RESULTS

The JMC-CDs ranged in diameter from 1.0 to 8 nm and had a yield of 0.12%. Moreover, JMC-CDs not only possessed remarkable hemostatic efficacy but could also prevent hemorrhage-induced liver injury, as demonstrated by the reduced serum levels of biochemical indicators of liver damage such as aspartate aminotransferase, alanine amino transferase, alkaline phosphatase, total bilirubin and direct bilirubin.

CONCLUSION

The JMC-CDs may have great potentials in clinical practice.

Melatonin Attenuates Acute Pancreatitis-Induced Liver Damage Through Akt-Dependent PPAR-γ Pathway

BACKGROUND

Despite melatonin treatment diminishes inflammatory mediator production and improves organ injury after acute pancreatitis (AP), the mechanisms remain unknown. This study explores whether melatonin improves liver damage after AP through protein kinase B (Akt)-dependent peroxisome proliferator activated receptor (PPAR)-γ pathway.

METHODS

Male Sprague-Dawley rats were subjected to cerulein-induced AP. Animals were treated with vehicle, melatonin, and melatonin plus phosphoinositide 3-kinase (PI3K)/Akt inhibitor wortmannin 1 h following the onset of AP. Various indicators and targeted proteins were checked at 8 h in the sham and AP groups.

RESULTS

At 8 h after AP, serum alanine aminotransferase/aspartate aminotransferase levels, histopathology score of hepatic injury, liver myeloperoxidase activity, and proinflammatory cytokine production were significantly increased and liver tissue adenosine triphosphate concentration was lower compared with shams. AP resulted in a marked decrease in liver Akt phosphorylation and PPAR-γ expression in comparison with the shams (relative density, 0.442 ± 0.037 versus. 1.098 ± 0.069 and 0.390 ± 0.041 versus ± 1.080 0.063, respectively). Melatonin normalized AP-induced reduction in liver tissue Akt activation (1.098 ± 0.054) and PPAR-γ expression (1.145 ± 0.083) as well as attenuated the increase in liver injury markers and proinflammatory mediator levels, which was abolished by coadministration of wortmannin.

CONCLUSIONS

Collectively, our findings suggest that melatonin improves AP-induced liver damage in rats, at least in part, via Akt-dependent PPAR-γ pathway.

Melatonin prevents chronic intermittent hypoxia-induced injury by inducing sirtuin 1-mediated autophagy in steatotic liver of mice

BACKGROUND

Hepatic steatosis that occasionally results in nonalcoholic steatohepatitis (NASH) is related to obstructive sleep apnea (OSA). Many studies have shown that autophagy exerts protective effects on liver damage caused by various diseases and melatonin exhibits hepatoprotective properties. However, the mechanisms of liver injury induced by chronic intermittent hypoxia (CIH) and the effect of melatonin on the regulation of liver injury remain unclear.

PURPOSE

This study was aimed to evaluate the role of CIH in steatohepatitis progression and the regulatory function of melatonin on fatty liver sensitivity to CIH injury, mainly focusing on autophagy signaling.

METHODS

A high-fat diet (FD)-induced obesity mouse model was subjected to intermittent hypoxia/normoxia events for approximately 8 h per day using an autophagy agonist, rapamycin, or an inhibitor, 3-methyladenine (3-MA), and SRT1720, a sirtuin 1 (SIRT1) activator, or sirtinol, a SIRT1 inhibitor, with or without melatonin for a total of six successive weeks, followed by assessment of expression of autophagy-related genes and activity of serum aminotransferase as well as histological evaluation of tissue morphology.

RESULTS

Neither FD nor CIH alone causes significant liver injury; however, the combination yielded higher serum aminotransferase activities and more severe histological changes, accompanied by a decrease in autophagy activity. Melatonin markedly inhibited FD/CIH-stimulated liver injury by enhancing autophagy. In contrast, SIRT1 inhibition resulted in a decrease in the expression of melatonin-induced autophagy-related genes as well as diminished its protective effects on FD/CIH-induced liver injury.

CONCLUSION

These results suggest that melatonin could ameliorate FD/CIH-induced hepatocellular damage by activating SIRT1-mediated autophagy signaling.

Hepatoprotective Effects of Corilagin Following Hemorrhagic Shock are Through Akt-Dependent Pathway

Corilagin, a component of Phyllanthus urinaria extract, possesses antioxidant, thrombolytic, antiatherogenic, and hepatoprotective properties, but the mechanism underlying these effects remains unclear. Previous studies showed that the Akt (protein kinase B) signaling pathway exerts anti-inflammatory and organ protective effects. The aim of this study was to investigate the mechanism of action of corilagin and determine whether these effects are mediated through the Akt-dependent pathway in a trauma-hemorrhagic shock-induced liver injury rodent model. Hemorrhagic shock was induced in male Sprague–Dawley rats; mean blood pressure was maintained at 35 mm Hg to 40 mm Hg for 90 min, followed by fluid resuscitation. During resuscitation, three doses of corilagin alone (1 mg/kg, 5 mg/kg, or 10 mg/kg, intravenously) were administered. Furthermore, a single dose of corilagin (5 mg/kg) with and without Wortmannin (1 mg/kg, PI3K inhibitor), Wortmannin alone, or vehicle was administered. Twenty-four hours after resuscitation, plasma alanine aminotransferase and aspartate aminotransferase concentration and hepatic parameters were measured. One-way ANOVA was used for statistical analysis. Hepatic myeloperoxidase activity and the concentrations of plasma alanine aminotransferase and aspartate aminotransferase, interleukin-6, tumor necrosis factor-α, intercellular adhesion molecule-1, and cytokine-induced neutrophil chemoattractant-1 (CINC-1) and CINC-3 increased following hemorrhagic shock. These parameters were significantly attenuated in corilagin-treated rats following hemorrhagic shock. Hepatic phospho-Akt expression was also higher in corilagin-treated rats than in vehicle-treated rats. The elevation of phospho-Akt was abolished by combined treatment with Wortmannin and corilagin. Our results suggest that corilagin exerts its protective effects on hemorrhagic shock-induced liver injury, at least, via the Akt-dependent pathway.

Mechanism of salutary effects of melatonin-mediated liver protection after trauma-hemorrhage: p38 MAPK-dependent iNOS/HIF-1α pathway

Although melatonin attenuates the increases in inflammatory mediators and reduces organ injury during trauma-hemorrhage, the mechanisms remain unclear. This study explored whether melatonin prevents liver injury after trauma-hemorrhage through the p38 mitogen-activated protein kinase (MAPK)-dependent, inducible nitrite oxide (iNOS)/hypoxia-inducible factor (HIF)-1α pathway. After a 5-cm midline laparotomy, male rats underwent hemorrhagic shock (mean blood pressure ~40 mmHg for 90 min) followed by fluid resuscitation. At the onset of resuscitation, rats were treated with vehicle, melatonin (2 mg/kg), melatonin plus p38 MAPK inhibitor SB203580 (2 mg/kg), or melatonin plus the melatonin receptor antagonist luzindole (2.5 mg/kg). At 2 h after trauma-hemorrhage, histopathology score of liver injury, liver tissue myeloperoxidase activity, malondialdehyde, adenosine triphosphate, serum alanine aminotransferase, and asparate aminotransferase levels were significantly increased compared with sham-operated control. Trauma-hemorrhage resulted in a significant decrease in the p38 MAPK activation compared with that in the sham-treated animals. Administration of melatonin after trauma-hemorrhage normalized liver p38 MAPK phosphorylation and iNOS and HIF-1α expression and attenuated cleaved caspase 3 and receptor interacting protein kinase-1 levels. Coadministration of SB203580 or luzindole abolished the melatonin-mediated attenuation of the trauma-hemorrhage-induced increase of iNOS/HIF-1α protein expression and liver injury markers. Taken together, our results suggest that melatonin prevents trauma-hemorrhage-induced liver injury in rats, at least in part, through melatonin receptor-related, p38 MAPK-dependent iNOS/HIF-1α pathway.NEW & NOTEWORTHY Trauma-hemorrhage resulted in a significant decrease in liver p38 MAPK activation and increase in nitrite oxide synthase (iNOS) and hypoxia-inducible factor (HIF)-1α expression. Administration of melatonin after trauma-hemorrhage normalized liver p38 MAPK phosphorylation and iNOS and HIF-1α expression, which was abolished by coadministration of SB203580 or luzindole. Melatonin prevents trauma-hemorrhage-induced liver injury in rats via the melatonin receptor-related, p38 MAPK-dependent iNOS/HIF-1α pathway.

Melatonin alleviates cadmium-induced liver injury by inhibiting the TXNIP-NLRP3 inflammasome

Cadmium (Cd) is a persistent environmental and occupational contaminant that accumulates in the liver and induces oxidative stress and inflammation. Melatonin possesses potent hepatoprotective properties against the development and progression of acute and chronic liver injury. Nevertheless, the molecular mechanism underlying the protective effects of melatonin against Cd-induced hepatotoxicity remains obscure. In this study, we aimed to investigate the effects of melatonin on Cd-induced liver inflammation and hepatocyte death. Male C57BL/6 mice were intraperitoneally injected with melatonin (10 mg/kg) once a day for 3 days before exposure to CdCl₂ (2.0 mg/kg). We found that Cd induced hepatocellular damage and inflammatory infiltration as well as increased serum ALT/AST enzymes. In addition, we showed that Cd triggered an inflammatory cell death, which is mediated by the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome. Moreover, melatonin treatment significantly alleviated Cd-induced liver injury by decreasing serum ALT/AST levels, suppressing pro-inflammatory cytokine production, inhibiting NLRP3 inflammasome activation, ameliorating oxidative stress, and attenuating hepatocyte death. Most importantly, melatonin markedly abrogated Cd-induced TXNIP overexpression and decreased the interaction between TXNIP and NLRP3 in vivo and in vitro. However, treatment with siRNA targeting TXNIP blocked the protective effects of melatonin in Cd-treated primary hepatocytes. Collectively, our results suggest that melatonin confers protection against Cd-induced liver inflammation and hepatocyte death via inhibition of the TXNIP-NLRP3 inflammasome pathway.

Effects of Melatonin on Liver Injuries and Diseases

Liver injuries and diseases are serious health problems worldwide. Various factors, such as chemical pollutants, drugs, and alcohol, could induce liver injuries. Liver diseases involve a wide range of liver pathologies, including hepatic steatosis, fatty liver, hepatitis, fibrosis, cirrhosis, and hepatocarcinoma. Despite all the studies performed up to now, therapy choices for liver injuries and diseases are very few. Therefore, the search for a new treatment that could safely and effectively block or reverse liver injuries and diseases remains a priority. Melatonin is a well-known natural antioxidant, and has many bioactivities. There are numerous studies investigating the effects of melatonin on liver injuries and diseases, and melatonin could regulate various molecular pathways, such as inflammation, proliferation, apoptosis, metastasis, and autophagy in different pathophysiological situations. Melatonin could be used for preventing and treating liver injuries and diseases. Herein, we conduct a review summarizing the potential roles of melatonin in liver injuries and diseases, paying special attention to the mechanisms of action.

Protective Effects of Silymarin, Alone or in Combination with Chlorogenic Acid and/or Melatonin, Against Carbon Tetrachloride-induced Hepatotoxicity

OBJECTIVE

The aim of this study was to evaluate the hepatoprotective effects of silymarin (SIL), alone and combined with chlorogenic acid (CA) and/or melatonin (ME), using a rat model of carbon tetrachloride (CCl4)-induced injury.

MATERIALS AND METHODS

Hepatotoxicity was induced by a single dose of CCl4 (1 ml/kg, IP). One day after, rats were received SIL (200 mg/kg) alone or in combination with CA (60 mg/kg) and/or ME (20 mg/kg) for 21 days.

RESULTS

SIL significantly decreased serum alanine aminotransferase, inflammatory cytokines, and vascular endothelial growth factor levels. Histological alterations, fibrogenesis, oxidative DNA damage, inflammatory mediators, and caspase-3 activity were significantly attenuated in SIL treated CCl4-intoxicated rats. On the other hand, cytochrome P450 2E1 activity showed a significant decrease in the liver of CCl4-intoxicated rats, an effect that was reversed following treatment with SIL. All beneficial effects of SIL were markedly potentiated when combined with CA and/or ME.

CONCLUSIONS

These data indicate that SIL, alone and combined with CA and/or ME, protected the liver against CCl4-induced hepatotoxicity via attenuating inflammation, oxidative DNA damage, apoptosis, and fibrotic changes. The significantly intensified hepatoprotective effects of SIL when combined with both CA and ME suggest a possible synergism. These synergistic effects need to be further confirmed using detailed studies.

SUMMARY

Silymarin, chlorogenic acid and melatonin possess in vivo hepatoprotective activitySilymarin, chlorogenic acid and melatonin attenuate fibrogenesis, oxidative DNA damage, inflammation and apoptosisChlorogenic acid and melatonin enhance the hepatoprotective effect of silymarin. Abbreviations used: SIL: silymarin, CA: chlorogenic acid, ME: melatonin, CCl4: carbon tetrachloride, CYP2E1, cytochrome P450 2E1, ALT: alanine aminotransferase, IL-6: interleukin 6, IFN-γ: interferon gamma, VEGF: vascular endothelial growth factor, TNF-α: tumor necrosis factor alpha, CRP: C-reactive protein, 8-OxodG: 8-Oxo-2'-deoxyguanosine, TGF-B1: transforming growth factor beta 1, HSCs: hepatic stellate cells.

Melatonin attenuated early brain injury induced by subarachnoid hemorrhage via regulating NLRP3 inflammasome and apoptosis signaling

Subarachnoid hemorrhage (SAH) is a devastating condition with high morbidity and mortality rates due to the lack of effective therapy. Nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation associated with the upregulation of apoptotic signaling pathway has been implicated in various inflammatory diseases including hemorrhagic insults. Melatonin is reported to possess substantial anti-inflammatory properties, which is beneficial for early brain injury (EBI) after SAH. However, the molecular mechanisms have not been clearly identified. This study was designed to investigate the protective effects of melatonin against EBI induced by SAH and to elucidate the potential mechanisms. The adult mice were subjected to SAH. Melatonin or vehicle was injected intraperitoneally 2 hr after SAH. Melatonin was neuroprotective, as shown by increased survival rate, as well as elevated neurological score, greater survival of neurons, preserved brain glutathione levels, and reduced brain edema, malondialdehyde concentrations, apoptotic ratio, and blood-brain barrier (BBB) disruption. Melatonin also attenuated the expressions of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cleaved caspase-1, interleukin-1β (IL-1β), and interleukin-6 (IL-6); these changes were also associated with an increase in the anti-apoptotic factor (Bcl2) and reduction in the pro-apoptotic factor (Bim). In summary, our results demonstrate that melatonin treatment attenuates the EBI following SAH by inhibiting NLRP3 inflammasome-associated apoptosis.

Melatonin attenuates sepsis-induced cardiac dysfunction via a PI3K/Akt-dependent mechanism

Myocardial dysfunction is an important manifestation of sepsis. Previous studies suggest that melatonin is protective against sepsis. In addition, activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway has been reported to be beneficial in sepsis. However, the role of PI3K/Akt signaling in the protective effect of melatonin against sepsis-induced myocardial dysfunction remains unclear. Here, LY294002, a PI3K inhibitor, was used to investigate the role of PI3K/Akt signaling in mediating the effects of melatonin on sepsis-induced myocardial injury. Cecal ligation and puncture (CLP) surgery was used to establish a rat model of sepsis. Melatonin was administrated to rats intraperitoneally (30 mg/kg). The survival rate, measures of myocardial injury and cardiac performance, serum lactate dehydrogenase level, inflammatory cytokine levels, oxidative stress level, and the extent of myocardial apoptosis were assessed. The results suggest that melatonin administration after CLP surgery improved survival rates and cardiac function, attenuated myocardial injury and apoptosis, and decreased the serum lactate dehydrogenase level. Melatonin decreased the production of the inflammatory cytokines TNF-α, IL-1β, and HMGB1, increased anti-oxidant enzyme activity, and decreased the expression of markers of oxidative damage. Levels of phosphorylated Akt (p-Akt), unphosphorylated Akt (Akt), Bcl-2, and Bax were measured by Western blot. Melatonin increased p-Akt levels, which suggests Akt pathway activation. Melatonin induced higher Bcl-2 expression and lower Bax expression, suggesting inhibition of apoptosis. All protective effects of melatonin were abolished by LY294002, the PI3K inhibitor. In conclusion, our results demonstrate that melatonin mitigates myocardial injury in sepsis via PI3K/Akt signaling activation.

The salutary effects of diphenyldifluoroketone EF24 in liver of a rat hemorrhagic shock model

Background

Liver is a target for injury in low flow states and it plays a central role in the progression of systemic failure associated with hemorrhagic shock. Pharmacologic support can help recover liver function even after it has suffered extensive damage during ischemia and reperfusion phases. In this work we assessed the efficacy of a diphenyldifluoroketone EF24, an IKKβ inhibitor, in controlling hepatic inflammatory signaling caused by hemorrhagic shock in a rat model.

Methods

Sprague Dawley rats were bled to about 50% of blood volume. The hemorrhaged rats were treated with vehicle control or EF24 (0.4 mg/kg) after 1 h of hemorrhage without any accompanying resuscitation. The study was terminated after additional 5 h to excise liver tissue for biochemical analyses and histology.

Results

EF24 treatment alleviated hemorrhagic shock-induced histologic injury in the liver and restored serum transaminases to normal levels. Hemorrhagic shock induced the circulating levels of CD163 (a marker for macrophage activation) and CINC (an IL-8 analog), as well as myeloperoxidase activity in liver tissue. These markers of inflammatory injury were reduced by EF24 treatment. EF24 treatment also suppressed the expression of the Toll-like receptor 4, phospho-p65/Rel A, and cyclooxygenase-2 in liver tissues, indicating that it suppressed inflammatory pathway. Moreover, it reduced the hemorrhagic shock-induced increase in the expression of high mobility group box-1 protein. The evidence for apoptosis after hemorrhagic shock was inconclusive.

Conclusion

Even in the absence of volume support, EF24 treatment suppresses pro-inflammatory signaling in liver tissue and improves liver functional markers in hemorrhagic shock.

Role of p38 MAPK pathway in 17β-estradiol-mediated attenuation of hemorrhagic shock-induced hepatic injury

Although 17β-estradiol (E2) treatment following hemorrhagic shock or ischemic reperfusion prevents organs from dysfunction and injury, the precise mechanism remains unknown. We hypothesize that the E2-mediated attenuation of liver injury following hemorrhagic shock and fluid resuscitation occurs via the p38 mitogen-activated protein kinase (MAPK)-dependent heme oxygenase (HO)-1 pathway. After a 5-cm midline laparotomy, male rats underwent hemorrhagic shock (mean blood pressure ∼40 mmHg for 90 min) followed by fluid resuscitation. At the onset of resuscitation, rats were treated with vehicle, E2 (1 mg/kg) alone, or E2 plus p38 MAPK inhibitor SB-203580 (2 mg/kg), HO-1 inhibitor chromium mesoporphyrin-IX chloride (2.5 mg/kg) or estrogen receptor antagonist ICI 182,780 (3 mg/kg). At 2 h after hemorrhagic shock and fluid resuscitation, the liver injury markers were significantly increased compared with sham-operated control. Hemorrhagic shock resulted in a significant decrease in p38 MAPK phosphorylation compared with the shams. Administration of E2 following hemorrhagic shock normalized liver p38 MAPK phosphorylation, further increased HO-1 expression, and reduced cleaved caspase-3 levels. Coadministration of SB-203580 abolished the E2-mediated attenuation of the shock-induced liver injury markers. In addition, administration of chromium mesoporphyrin-IX chloride or ICI 182,780 abolished E2-mediated increases in liver HO-1 expression or p38 MAPK activation following hemorrhagic shock. Our results collectively suggest that the salutary effects of E2 on hepatic injury following hemorrhagic shock and resuscitation are in part mediated through an estrogen-receptor-related p38 MAPK-dependent HO-1 upregulation.

Certain Diet and Lifestyle May Contribute to Islet β-cells Protection in Type-2 Diabetes via the Modulation of Cellular PI3K/AKT Pathway

PI3K/AKT pathway has been shown to play a pivotal role on islet β-cell protection, enhancing β-cell survival by stimulating cell proliferation and inhibiting cell apoptosis. Accordingly, this pathway appears to be crucial in type-2 diabetes. Understanding the regulations of this pathway may provide a better efficacy of new therapeutic approaches. In this review, we summarize advances on the involvement of the PI3K/AKT pathway in hypothetical intra-cellular signaling of islet β-cells. As recent findings may show the nutritional regulation of the survival pathway in the islet β-cells through activation of the PI3K/AKT pathway, we also review studies on the features of several diets, correlated lifestyle, and its signaling pathway involved in type-2 diabetes. The molecular mechanisms contributing to the disease are the subject of considerable investigation, as a better understanding of the pathogenesis will lead to novel therapies against a condition of the disease.

Melatonin and the theories of aging: a critical appraisal of melatonin's role in antiaging mechanisms

The classic theories of aging such as the free radical theory, including its mitochondria-related versions, have largely focused on a few specific processes of senescence. Meanwhile, numerous interconnections have become apparent between age-dependent changes previously thought to proceed more or less independently. Increased damage by free radicals is not only linked to impairments of mitochondrial function, but also to inflammaging as it occurs during immune remodeling and by release of proinflammatory cytokines from mitotically arrested, DNA-damaged cells that exhibit the senescence-associated secretory phenotype (SASP). Among other effects, SASP can cause mutations in stem cells that reduce the capacity for tissue regeneration or, in worst case, lead to cancer stem cells. Oxidative stress has also been shown to promote telomere attrition. Moreover, damage by free radicals is connected to impaired circadian rhythmicity. Another nexus exists between cellular oscillators and metabolic sensing, in particular to the aging-suppressor SIRT1, which acts as an accessory clock protein. Melatonin, being a highly pleiotropic regulator molecule, interacts directly or indirectly with all the processes mentioned. These influences are critically reviewed, with emphasis on data from aged organisms and senescence-accelerated animals. The sometimes-controversial findings obtained either in a nongerontological context or in comparisons of tumor with nontumor cells are discussed in light of evidence obtained in senescent organisms. Although, in mammals, lifetime extension by melatonin has been rarely documented in a fully conclusive way, a support of healthy aging has been observed in rodents and is highly likely in humans.

Folic acid and melatonin ameliorate carbon tetrachloride-induced hepatic injury, oxidative stress and inflammation in rats

This study investigated the protective effects of melatonin and folic acid against carbon tetrachloride (CCl4)-induced hepatic injury in rats. Oxidative stress, liver function, liver histopathology and serum lipid levels were evaluated. The levels of protein kinase B (Akt1), interferon gamma (IFN-γ), programmed cell death-receptor (Fas) and Tumor necrosis factor-alpha (TNF-α) mRNA expression were analyzed. CCl4 significantly elevated the levels of lipid peroxidation (MDA), cholesterol, LDL, triglycerides, bilirubin and urea. In addition, CCl4 was found to significantly suppress the activity of both catalase and glutathione (GSH) and decrease the levels of serum total protein and HDL-cholesterol. All of these parameters were restored to their normal levels by treatment with melatonin, folic acid or their combination. An improvement of the general hepatic architecture was observed in rats that were treated with the combination of melatonin and folic acid along with CCl4. Furthermore, the CCl4-induced upregulation of TNF-α and Fas mRNA expression was significantly restored by the three treatments. Melatonin, folic acid or their combination also restored the baseline levels of IFN-γ and Akt1 mRNA expression. The combination of melatonin and folic acid exhibited ability to reduce the markers of liver injury induced by CCl4 and restore the oxidative stability, the level of inflammatory cytokines, the lipid profile and the cell survival Akt1 signals.

Role of Akt/HO-1 pathway in estrogen-mediated attenuation of trauma-hemorrhage-induced lung injury

BACKGROUND

Despite advances in intensive care medicines, hemorrhagic shock leading to multiple organ failure remains the major causes of death in the injured host. Although studies have shown that 17β-estradiol (E2) prevents trauma-hemorrhage-induced lung damage, it remains unknown whether protein kinase B (Akt)/heme oxygenase (HO)-1 plays any role in E2-mediated lung protection after trauma-hemorrhage.

MATERIALS AND METHODS

After a 5-cm midline laparotomy, male rats underwent hemorrhagic shock (mean blood pressure ∼40 mm Hg for 90 min) followed by fluid resuscitation. At the onset of resuscitation, rats were treated with vehicle, E2 (1 kg/mg), E2 plus phosphoinositide 3-kinase inhibitor LY294002 (5 mg/kg), or LY294002. At 2 h after trauma-hemorrhage or sham operation, lung tissue myeloperoxidase activity, wet-to-dry-weight ratio, inflammatory mediators, and apoptosis were measured. Lung Akt, HO-1, and cleaved caspase-3 protein levels were also determined.

RESULTS

E2 attenuated the trauma-hemorrhage-induced increase in lung myeloperoxidase activity, edema formation, inflammatory mediator levels, and apoptosis, which was blocked by co-administration of LY294002. Administration of E2 normalized lung Akt phosphorylation and further increased HO-1 expression and decreased cleaved caspase-3 levels after trauma-hemorrhage. Co-administration of LY294002 prevented the E2-mediated attenuation of shock-induced lung injury.

CONCLUSIONS

Our results collectively suggest that Akt-dependent HO-1 upregulation may play a critical role in E2-meditated lung protection after trauma-hemorrhage.