The role of curcumin on intestinal oxidative stress, cell proliferation and apoptosis after ischemia/reperfusion injury in rats

Curcumin attenuates neuroinflammatory damage induced by LPS: implications for the role of S100B

Brain disease results in inflammatory damage that alters cell function in microglia and astrocytes as well as other neuronal cell types. Astrocytes modulate blood flow, regulate glutamate metabolism, and exert antioxidant protection. When responding to inflammatory damage, astrocytes enhance immune cell infiltration and amplify inflammatory responses via the upregulation of cytokine production. Several molecules have been proposed to attenuate neuroinflammation and control neurological diseases. Curcumin gained attention due to its capacity to cross the blood-brain barrier and its well-described anti-inflammatory and antioxidant activities. Our study aimed to understand if oral curcumin administration could protect against central nervous system inflammatory damage induced by intracerebroventricular injection of LPS while focusing on astrocyte function. Despite its poor bioavailability, we found that curcumin reaches the central nervous system, prevents the locomotory damage caused by LPS, and reduces inflammatory signaling via IL-1β and COX-2. Furthermore, we observed that curcumin was protective against LPS-induced S100B secretion in the cerebrospinal fluid and GSH reduction in the hippocampal tissue. However, curcumin could not protect the animals from anhedonia, assessed by the sucrose preference test, and weight loss induced by LPS. Our results indicate that oral curcumin administration exerts a protective anti-inflammatory action in the central nervous system, attenuating the sickness behavior induced by ICV LPS. This work demonstrates that curcumin has an important modulative effect on astrocytes, thus suggesting that astrocytes are critical to the anti-inflammatory effects of curcumin.

Curcumin suppresses the Wnt/β-catenin signaling pathway by inhibiting NKD2 methylation to ameliorate intestinal ischemia/reperfusion injury

Intestinal ischemia/reperfusion (I/R) injury is a life-threatening condition with no effective treatment currently available. Curcumin (CCM), a polyphenol compound in Curcuma Longa, reportedly has positive effects against intestinal I/R injury. However, the mechanism underlying the protective effect of CCM against intestinal I/R injury has not been fully clarified. To determine whether the protective effect of CCM was mediated by epigenetic effects on Wnt/β-catenin signaling, the effect of CCM was examined in vivo and in vitro. An intestinal I/R model was established in Sprague-Dawley (SD) rats with superior mesenteric artery occlusion, and Caco-2 cells were subjected to hypoxia/reoxygenation (H/R) for in vivo simulation of I/R. The results showed that CCM significantly reduced inflammatory, cell apoptosis, and oxidative stress induced by I/R insult in vivo and in vitro. Western blot analysis showed that CCM preconditioning reduced the protein levels of β-catenin, p-GSK3β, and cyclin-D1 and increased the protein level of GSK3β compared with the I/R group. Overexpressing β-catenin aggravated H/R injury, and knocking down β-catenin relieved H/R injury by improving intestinal permeability and reducing the cell apoptosis. Moreover, Naked cuticle homolog 2(NKD2) mRNA and protein levels were upregulated in the CCM-pretreated group. 5-aza-2'-deoxycytidine (5-AZA) treatment improved intestinal epithelial barrier impairment induced by H/R. Besides, the protein levels of total β-catenin, phosphor-β-catenin and cyclin-D1 were reduced after overexpressing NKD2 in Caco-2 cells following H/R insult. In conclusion, Our study suggests that CCM could attenuate intestinal I/R injury in vitro and in vivo by suppressing the Wnt/β-catenin signaling pathway via inhibition of NKD2 methylation.

Prophylactic Treatment of Intestinal Ischemia-Reperfusion Injury Reduces Mucosal Damage and Improves Intestinal Absorption

Purpose

Intestinal ischemia-reperfusion injury (i-IRI) involves a blood flow interruption in an intestinal segment followed by blood flow restoration. When blood flow is restored, oxidative and inflammatory molecules are distributed throughout the bloodstream, triggering both local and systemic damage. Our goal was to evaluate the potential of three antioxidant and/or anti-inflammatory compounds (curcumin, dexmedetomidine and α-tocopherol) to prevent or reverse local and systemic damage induced by i-IRI.

Methods

i-IRI was induced by placing a microvascular clip in the superior mesenteric artery of female WAG/RijHsd rats; the clip was removed after 1h and reperfusion was allowed for 4h. Curcumin (200 mg/kg, orally), α-tocopherol (20 mg/kg, i.p.), and dexmedetomidine (5 or 20 µg/kg, s.c.; DEX5 and DEX20, respectively) were administered. Blood and terminal ileum specimens were collected for biochemical and histological determination. Furthermore, D-xylose absorption test was performed to evaluate intestinal absorption; after completing the 1-hour ischemia and 4-hour reperfusion period, 1 mL of aqueous D-xylose solution (0.615 mg/mL) was administered orally, and one hour later, plasma D-xylose levels were quantified.

Results

The histological injury degree (HID) measured by the Chiu scale was significantly reduced when the treatments were applied (non-treated rats, 2.6 ± 0.75; curcumin, 1.54 ± 0.8; DEX5, 1.47 ± 0.7; DEX20 1.14 ± 0.5; and α-tocopherol, 1.01 ± 0.6); intestinal absorptive capacity also improved in all cases healthy rats (2.06 ± 0.07 µg/mL; non-treated, 1.18 ± 0.07 µg/mL; curcumin 1.76 ± 0.3 µg/mL; DEX5, 2.29 ± 0.2 µg/mL; DEX20, 2.25 ± 0.26 µg/mL; and α-tocopherol 1.66 ± 0.21 µg/mL). However, it failed to reduce liver enzyme levels. Finally, only dexmedetomidine significantly reduced urea and creatinine levels compared to non-treated animals.

Conclusion

All drugs were effective in reducing HID, although α-tocopherol was effective to a greater extent. Only dexmedetomidine reverted intestinal absorption to normal values of healthy animals.

Protective effects of curcumin on ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury is a term used to describe phenomena connected to the dysfunction of various tissue damage due to reperfusion after ischemic injury. While I/R may result in systemic inflammatory response syndrome or multiple organ dysfunction syndrome, there is still a long way to improve therapeutic outcomes. A number of cellular metabolic and ultrastructural alterations occur by prolonged ischemia. Ischemia increases the expression of proinflammatory gene products and bioactive substances within the endothelium, such as cytokines, leukocytes, and adhesion molecules, even as suppressing the expression of other "protective" gene products and substances, such as thrombomodulin and constitutive nitric oxide synthase (e.g., prostacyclin, nitric oxide [NO]). Curcumin is the primary phenolic pigment derived from turmeric, the powdered rhizome of Curcuma longa. Numerous studies have shown that curcumin has strong antiinflammatory and antioxidant characteristics. It also prevents lipid peroxidation and scavenges free radicals like superoxide anion, singlet oxygen, NO, and hydroxyl. In our study, we highlight the mechanisms of protective effects of curcumin against I/R injury in various organs.

Potential complementary and/or synergistic effects of curcumin and boswellic acids for management of osteoarthritis

For several thousand years (~4000) Boswellia serrata and Curcuma longa have been used in Aryuvedic medicine for treatment of various illnesses, including asthma, peptic ulcers, and rheumatoid arthritis, all of which are mediated through pathways associated with inflammation and pain. Although the in vivo pharmacology of both these natural ingredients is difficult to study because of poor bioavailability, in vitro data suggest that both influence gene expression mediated through nuclear factor kappa B (NF-κB). Therefore, the activity of pathways associated with inflammation (including NF-κB and lipoxygenase- and cyclooxygenase-mediated reduction in leukotrienes/prostaglandins) and those involved in matrix degradation and apoptosis are reduced, resulting in a reduction in pain. Additive activity of boswellic acids and curcumin was observed in preclinical models and synergism was suggested in clinical trials for the management of osteoarthritis (OA) pain. Overall, studies of these natural ingredients, alone or in combination, revealed that these extracts relieved pain from OA and other inflammatory conditions. This may present an opportunity to improve patient care by offering alternatives for patients and physicians, and potentially reducing nonsteroidal anti-inflammatory or other pharmacologic agent use. Additional research is needed on the effects of curcumin on the microbiome and the influence of intestinal metabolism on the activity of curcuminoids to further enhance formulations to ensure sufficient anti-inflammatory and antinociceptive activity. This narrative review includes evidence from in vitro and preclinical studies, and clinical trials that have evaluated the mechanism of action, pharmacokinetics, efficacy, and safety of curcumin and boswellic acids individually and in combination for the management of OA pain.

GSK-3β RNAi Lentivirus Affects Neuronal Damage and Nuclear Factor E2-Related Factor 2 (Nrf2) Expression in Cerebral Infarction Rats

We investigated the effect of GSK-3β RNAi lentivirus on neuronal damage and Nrf2 level in rats with cerebral infarction. 40 rats were assigned into sham group, CI group, Vector group and GSK-3β RNAi group followed by analysis of cell damage and oxidative stress, neurological scores, cerebral infarction volume, and brain water content as well as brain morphology by H&E staining and Nrf2 protein level by Western blot. Compared with sham group, GSK-3β mRNA in neurons of CI group and Vector group was significantly elevated (P < 0.05) with reduced level in GSK-3β RNAi group (P < 0.05); 3 hours after surgery, there was no change in neuroethology scores of rats in CI group, Vector group and GSK-3β RNAi group (P > 0.05). While 1 and 3 days later, the scores of rats were significantly improved (P < 0.05) and brain water content was reduced in GSK-3β RNAi group (P < 0.05) without difference between CI group and Vector group (P > 0.05). Compared with sham group, infarct size in CI group and Vector group was increased (P < 0.05) and reduced in GSK-3β RNAi group (P < 0.05) without difference between CI group and Vector group (P > 0.05). Meanwhile, CI group and Vector group showed significantly downregulated Nrf2, Srx1 and Trx1 proteins (P < 0.05), which were increased in GSK-3β RNAi group (P < 0.05). In conclusion, GSK-3β RNAi lentivirus can promote the expression of Nrf2 and exert an inhibitory effect on neurons of rats with cerebral infarction, therefore protecting brain tissue.

Curcumin and Intestinal Oxidative Stress of Pigs With Intrauterine Growth Retardation: A Review

Intrauterine growth restriction (IUGR) refers to the slow growth and development of a mammalian embryo/fetus or fetal organs during pregnancy, which is popular in swine production and causes considerable economic losses. Nutritional strategies have been reported to improve the health status and growth performance of IUGR piglets, among which dietary curcumin supplementation is an efficient alternative. Curcumin is a natural lipophilic polyphenol derived from the rhizome of Curcuma longa with many biological activities. It has been demonstrated that curcumin promotes intestinal development and alleviates intestinal oxidative damage. However, due to its low bioavailability caused by poor solubility, chemical instability, and rapid degradation, the application of curcumin in animal production is rare. In this manuscript, the structural-activity relationship to enhance the bioavailability, and the nutritional effects of curcumin on intestinal health from the aspect of protecting piglets from IUGR associated intestinal oxidative damage were summarized to provide new insight into the application of curcumin in animal production.

High altitude exposures and intestinal barrier dysfunction

Gastrointestinal complaints are often reported during ascents to high altitude (> 2500 m), though their etiology is not known. One potential explanation is injury to the intestinal barrier which has been implicated in the pathophysiology of several diseases. High altitude exposures can reduce splanchnic perfusion and blood oxygen levels causing hypoxic and oxidative stress. These stressors might injure the intestinal barrier leading to consequences such as bacterial translocation and local/systemic inflammatory responses. The purpose of this mini review is to 1) discuss the impact of high-altitude exposures on intestinal barrier dysfunction, and 2) present medications and dietary supplements which may have relevant impacts on the intestinal barrier during high-altitude exposures. There is a small but growing body of evidence which shows that acute exposures to high altitudes can damage the intestinal barrier. Initial data also suggests that prolonged hypoxic exposures can compromise the intestinal barrier through alterations in immunological function, microbiota, or mucosal layers. Exertion may worsen high-altitude related intestinal injury via additional reductions in splanchnic circulation and greater hypoxemia. Collectively these responses can result in increased intestinal permeability and bacterial translocation causing local and systemic inflammation. More research is needed to determine the impact of various medications and dietary supplements on the intestinal barrier during high-altitude exposures.

Protective effects of nanocurcumin against stress-induced deterioration in the intestine

The therapeutic activities of curcumin have long been investigated in some chronic and inflammatory diseases. This study was designed to investigate the protective effects of nanocurcumin on intestinal barrier function, apoptosis, and oxidative stress in rats exposed to traffic noise. Forty rats were divided into four groups: two traffic noise-exposed groups of animals that received either vehicle (NOISE) or nanocurcumin (NCUR + NOISE) and two control groups that either remained intact (CON) or received nanocurcumin (NCUR). Nanocurcumin injection (15 mg/Kg/ip) and traffic noise exposure were administered daily for two weeks. The relative protein expression of intestinal tight junctions, occludin, and ZO-1 and Bax/Bcl-2 ratio was measured to evaluate barrier integrity and apoptosis in intestinal samples, respectively. Plasma D-lactate concentration was examined as a criterion of intestinal permeability. Corticosterone, superoxide dismutase (SOD) activity, glutathione (GSH), total antioxidant capacity (TAC), and nitrite were measured in serum. The noise exposure increased Bax/Bcl-2 ratio, corticosterone, and oxidative stress in the NOISE animals. Nanocurcumin treatment improved the Bax/Bcl-2 ratio and reduced corticosterone and oxidative stress in the NCUR + NOISE animals. The expression of tight junction proteins was decreased while the concentration of D-lactate was increased in the NOISE animals. Nanocurcumin did not efficiently impact the expression of tight junction proteins and the D-lactate level in the NCUR + NOISE group. Nanocurcumin administration displayed antioxidant and anti-apoptotic roles in the noise-exposed rats, however, it did not affect the intestinal barrier integrity. We concluded that reduced apoptosis in the intestine might be related to the antioxidant activity of nanocurcumin and its modulatory effects on the HPA axis in the nanocurcumin-treated animals.

Nutritional considerations to counteract gastrointestinal permeability during exertional heat stress

Intestinal barrier integrity and function are compromised during exertional heat stress (EHS) potentially leading to consequences that range from minor gastrointestinal (GI) disturbances to fatal outcomes in exertional heat stroke or septic shock. This mini-review provides a concise discussion of nutritional interventions that may protect against intestinal permeability during EHS and suggests physiological mechanisms responsible for this protection. Although diverse nutritional interventions have been suggested to be protective against EHS-induced GI permeability, the ingestion of certain amino acids, carbohydrates, and fluid per se is potentially effective strategy, whereas evidence for various polyphenols and pre/probiotics is developing. Plausible physiological mechanisms of protection include increased blood flow, epithelial cell proliferation, upregulation of intracellular heat shock proteins, modulation of inflammatory signaling, alteration of the GI microbiota, and increased expression of tight junction (TJ) proteins. Further clinical research is needed to propose specific nutritional candidates and recommendations for their application to prevent intestinal barrier disruption and elucidate mechanisms during EHS.

Apigenin-7-O-β-d-(6″-p-coumaroyl)-glucopyranoside reduces myocardial ischaemia/reperfusion injury in an experimental model via regulating the inflammation response

Context: Traditionally, Clematis tangutica Korsh. (Ranunculaceae) is used as a Tibetan herb for treating indigestion and blood stasis in China. Recently, a flavonoid glycoside, apigenin-7-O-β-d-(6″-p-coumaroyl)-glucopyranoside (APG), was isolated from the whole plant of C. tangutica.Objective: To investigate the cardioprotective effects of APG against myocardial ischaemia/reperfusion injury (MI/RI) and the possible mechanism.Materials and methods: Animals were subjected to 30 min/3 h MI/RI model. At the end of reperfusion, infarct size (IS), histopathology, serum levels CK-MB, LDH, TNF-α, IL-6 and MPO activities were detected. Phospho-IκB-α, ICAM-1 and NF-κB were assessed in vivo. Neonatal rat cardiomyocytes were pre-treated with or without APG, followed by stimulation with 8 h/2 h oxygen and glucose deprived/reoxygenation (OGD/R) model. Cell viability, LDH and cardiomyocyte apoptosis were assessed. The expression levels of phospho-IκB-α and NF-κB were measured in vitro.Results: Treatment with APG significantly reduced the following indicators in vivo (p < 0.05): (1) the IS (16.2%); (2) morphology score (1.67); (3) myocardial injury enzymes: CK-MB (26.2 ng/mL) and LDH (688 U/L); (4) pro-inflammatory cytokines: TNF-α (31.5 pg/mL) and IL-6 (163.8 pg/mL); (5) MPO activity (2.75 U/mg); (6) expression levels of phospho-IκB-α (0.47), NF-κB (2.87) and ICAM-1 (10.2). Moreover, treatment with APG also remarkably (p < 0.05) attenuated the following indicators in vitro: (1) LDH level (206 U/L); (2) cardiomyocyte apoptosis; (3) phospho-IκB-α (1.37) and NF-κB (2.50).Conclusions: APG possesses protective effects against MI/RI injury in rats and OGD/R-induced injury in cardiomyocytes by suppressing translocation of NF-κB and reducing inflammatory response; consequently, APG is helpful for treatment of ischaemic heart disease.

MiR-23a-5p exacerbates intestinal ischemia-reperfusion injury by promoting oxidative stress via targeting PPAR alpha

MiR-23a-5p is involved in the occurrence and development of some serious diseases, but its effects on intestinal ischemia-reperfusion (II/R) injury is unclear. In this research, the hypoxia/reoxygenation (H/R) model on IEC-6 cells and II/R model in mice were used. The data showed that the ROS level in model group was significantly increased compared with control group. The level of intestinal MPO was increased and serum SOD was decreased in mice compared with sham group. Moreover, the expression levels of miR-23a-5p in model groups were obviously increased in vitro and in vivo, while the expression levels of PPARα, FOXO3α, PGC-1α, Nrf2, CAT, NQO1, HO-1 and SOD2 were significantly decreased. The double luciferase reporter gene assay showed that there was binding site between miR-23a-5p and PPARα. When miR-23a-5p was inhibited or PPARα gene was overexpressed, H/R-caused cell damage was alleviated and ROS level was decreased compared with NC group. PPARα expression level was increased, accompanied by the increased levels of FOXO3α, PGC-1α, Nrf2, CAT, NQO1, HO-1 and SOD2. After enhancing miR-23a-5p expression or silencing PPARα gene, H/R-caused cell damage was further aggravated compared with NC group, and ROS level was increased associated with the decreased levels of FOXO3α, PGC-1α, Nrf2, CAT, NQO1, HO-1 and SOD2. Our study demonstrated that miR-23a-5p exacerbated II/R injury by promoting oxidative stress via targeting PPARα, which should be considered as one new drug target to treat II/R injury.

Curcumin ameliorates oxidative stress-induced intestinal barrier injury and mitochondrial damage by promoting Parkin dependent mitophagy through AMPK-TFEB signal pathway

The gut epithelial is known as the most critical barrier for protection against harmful antigens and pathogens. Oxidative stress has been implicated in the dysfunction of the intestine barrier. Hence, effective and safe therapeutic approaches for maintaining intestinal redox balance are urgently needed. Curcumin has gained attention for its vast beneficial biological function via antioxidative stress. However, whether the curcumin can relief intestine damage and mitochondrial injury induced by oxidative stress is still unclear. In this study, we found that curcumin can effectively ameliorate hydrogen peroxide (H₂O₂)-induced oxidative stress, intestinal epithelial barrier injury and mitochondrial damage in porcine intestinal epithelial cells (IPEC-J2 cells) in a PTEN-induced putative kinase (PINK1)-Parkin mitophagy dependent way. Mechanistically, depletion of Parkin (a mitophagy related protein) abolished curcumin's protective action on anti-oxidative stress, improving intestinal barrier and mitochondrial function in porcine intestinal epithelial cells (IPEC-J2) induced by H₂O₂. Consistently, the protective effect of curcumin was not found in cells transfected with GFP-ParkinΔUBL, which encodes a mutant Parkin protein without the ubiquitin E3 ligase activity, indicating that the ubiquitin E3 ligase of Parkin is required for curcumin's protective effects. On the other hand, we also found that the protective function of curcumin was diminished when PRKAA1 was depleted in IPEC-J2 cells treated with H₂O₂. Immunofluorescence and luciferase assay showed that curcumin dramatically enhanced nuclear translocation and transcriptional activity of transcription factor EB (TFEB) in IPEC-J2 cells treated with H₂O₂, and it was ameliorated by co-treated with compound C, an Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) inhibitor, which means curcumin promotes TFEB transcript via AMPK signal pathway. Consistent with in vitro data, dietary curcumin protected intestinal barrier function, improved redox status, alleviated mitochondrial damage, triggered mitophagy and influenced AMPK-TFEB signal pathway in a well-established pig oxidative stress model by challenging with diquat. Taken together, these results unveil that curcumin ameliorates oxidative stress, enhances intestinal barrier function and mitochondrial function via the induction of Parkin dependent mitophagy through AMPK activation and subsequent TFEB nuclear translocation.

Curcumin Alleviates IUGR Jejunum Damage by Increasing Antioxidant Capacity through Nrf2/Keap1 Pathway in Growing Pigs

Simple Summary

Intrauterine growth retardation (IUGR) is usually defined as fetal growth below the 10th percentile for gestational age and results in impaired growth and development of the fetus and/or its organs during gestation. IUGR not only has a permanent effect on postnatal growth and long-term health, but also results in high fetal mortality and morbidity. Recent results have demonstrated that IUGR can cause jejunum damage in piglets. The jejunum is not only the main organ for the digestion and absorption of nutrients, but also an immune organ in the body. However, few effective methods to alleviate jejunum damage and oxidative stress in IUGR pigs have been found. In recent years, studies have found that curcumin (CUR) may be an effective and safe feed additive for regulating oxidative stress in the body. Our results indicated that dietary added 200 mg/kg curcumin to the basal diet can increase the antioxidant capacity of the IUGR growing pigs, jejunum and alleviate the damage in jejunum of the IUGR growing pigs. Therefore, the use of curcumin as a feed additive has certain economic value.

Abstract

The purpose of this study was to explore the effects of curcumin on IUGR jejunum damage. A total of 24 IUGR and 12 normal-birth weight (NBW) female crossbred (Duroc × Landrace × Large White) piglets were randomly assigned into three groups at weaning (26 days): IUGR group, NBW group, and IUGR + CUR group, which were fed diets containing 0 mg/kg (NBW), 0 mg/kg (IUGR) and 200 mg/kg (IUGR + CUR) curcumin from 26 to 115 days of age. Results showed that dietary supplementation with 200 mg/kg curcumin significantly increased the total superoxide dismutase (T-SOD) activity and decreased the malondialdehyde (MDA) content in the jejunum of IUGR pigs (p < 0.05). Results of real-time PCR showed that the IUGR + CUR group significantly increased the gene expression of NF-E2-related factor 2 (Nrf2) (p < 0.05), and increased the glutamate-cysteine ligase catalytic subunit (GCLC), superoxide dismutase 1 (SOD1), glutamate-cysteine ligase modifier subunit (GCLM), and NAD(P)H quinone dehydrogenase 1 (NQO1) mRNA expression compared with the IUGR group (p < 0.05). Western blot results showed that dietary supplementation with 200 mg/kg curcumin significantly increased the protein levels of Nrf2 and NQO1. Compared with the IUGR group, pigs in IUGR + CUR group showed significantly decreased the levels of tumor necrosis factor-α (TNFα), interleukin-6 (IL-6), and interferon gamma (IFNγ) (p < 0.05), and increased the interleukin-2 (IL-2) level (p < 0.05). Dietary supplementation with 200 mg/kg curcumin significantly reduced cysteinyl aspartate specific proteinase 3 (caspase3), BCL2-associated X protein (bax), B-cellCLL/lymphoma 2 (bcl2), and heat-shock protein 70 (hsp70) mRNA expression, and increased occludin (ocln) mRNA expression (p < 0.05). In conclusion, dietary supplementation with 200 mg/kg curcumin can alleviate jejunum damage in IUGR growing pigs, through Nrf2/Keap1 pathway.

Curcumin attenuates hypoxia/reoxygenation‑induced cardiomyocyte injury by downregulating Notch signaling

Recovery of the blood supply is the most effective treatment against ischemic heart disease; however, it is also a major cause of myocardial ischemia/reperfusion injury in clinical therapy. Curcumin has been reported to possess beneficial effects against hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury by regulating cell proliferation, apoptosis and antioxidant enzyme activity. The aim of the present study was to investigate the molecular mechanisms underlying the effects of curcumin on H/R-injured cardiomyocytes. H9C2 cardiomyocytes were pretreated with curcumin, and then cultured under H/R conditions. The viability of H9C2 cells was measured using a Cell Counting kit-8 assay, and the levels of intracellular lactate dehydrogenase (LDH), malondialdehyde (MDA) and superoxide dismutase (SOD) were measured to assess cell injury. Levels of reactive oxygen species (ROS) and apoptosis were evaluated by flow cytometry. The expression levels of Notch intracellular domain (NICD) and numerous downstream genes were analyzed via reverse transcription-quantitative polymerase chain reaction and western blotting. The results revealed that curcumin protected H9C2 cells against H/R-induced injury, reversing the H/R-induced increases in LDH and MDA levels, and decreases in SOD levels. ROS levels in H/R-induced cells were also significantly downregulated by curcumin treatment (P<0.01), and the apoptotic rate was significantly decreased from 15.13% in the H/R group to 7.7% in the H/R + curcumin group (P<0.01). The expression levels of NICD, hairy and enhancer of split (Hes)-1, Hes-5 and hairy/enhancer-of-split related with YRPW motif protein 1 (Hey-1) were significantly decreased in H/R-treated cells following curcumin treatment. Treatment with Jagged1 attenuated the effects of curcumin on cell viability, ROS levels and apoptosis; the Notch pathway was also reactivated. The present study indicated that there was a role for the Notch pathway in the protective effects of curcumin against H/R-induced cardiomyocyte injury, suggesting that downregulation of the Notch pathway may alleviate H/R-induced injury in H9C2 cells.

Food matrix and co-presence of turmeric compounds influence bioavailability of curcumin in healthy humans

Turmeric enhances curcumin bioavailability in healthy men.

Wound Healing Properties of Selected Natural Products

Wound healing is a complex process of recovering the forms and functions of injured tissues. The process is tightly regulated by multiple growth factors and cytokines released at the wound site. Any alterations that disrupt the healing processes would worsen the tissue damage and prolong repair process. Various conditions may contribute to impaired wound healing, including infections, underlying diseases and medications. Numerous studies on the potential of natural products with anti-inflammatory, antioxidant, antibacterial and pro-collagen synthesis properties as wound healing agents have been performed. Their medicinal properties can be contributed by the content of bioactive phytochemical constituents such as alkaloids, essential oils, flavonoids, tannins, saponins, and phenolic compounds in the natural products. This review highlights the in vitro, in vivo and clinical studies on wound healing promotions by the selected natural products and the mechanisms involved.

Protective Role of Dexmedetomidine on Ileum and Kidney Damage Caused by Mesenchymal Ischaemia in Rats

Objective

The aim of this study was to demonstrate ischaemia reperfusion (IR) injury on the ileum and kidney tissue in rats and to evaluate the effect of dexmedetomidine administered at different doses and dosing schedules on recovery.

Methods

A total of 30 rats were randomly divided into five groups. Group I: sham; Group II: control; Group III: dexmedetomidine before ischaemia; Group IV: dexmedetomidine after ischaemia; and Group V: dexmedetomidine before and after ischaemia. The malondialdehyde (MDA) and signal peptide-CUB-EGF (epidermal growth factor) domain-containing protein 1 (SCUBE-1) levels of all subjects were studied from the serum, ileum, and kidney tissues. Moreover, the histopathology of ileum and kidney tissues was examined.

Results

The SCUBE-1 levels were found to be highly similar to the MDA levels in ischaemic groups. The serum SCUBE-1 levels obtained were significantly lower in Group V compared to Groups II, III and IV (p<0.001, p=0.003, p=0.013, respectively). The apoptosis indexes were found to be lower in groups receiving dexmedetomidine compared to Group II. The groups receiving dexmedetomidine were detected to have normal morphological appearance when compared to Group II.

Conclusion

In this study, the use of dexmedetomidine in the preoperative and peroperative periods may be beneficial in reducing the negative effects of IR injury.

Protective mechanisms of hypaconitine and glycyrrhetinic acid compatibility in oxygen and glucose deprivation injury

This study investigated the protective effect of the compatibility of hypaconitine (HA) and glycyrrhetinic acid (GA) on H9c2 cells under oxygen and glucose deprivation (OGD)-induced injury, and the possible mechanisms. We found that HA+GA significantly improved pathology and morphology of the nucleus and ultrastructure of H9c2 cells under OGD as determined by Hoechst 33342 staining and transmission electron microscopy (TEM) tests. It also reduced the releases of lactate dehydrogenase (LDH), creatine kinase-myocardial band isoenzyme (CK-MB), and aspartate transaminase (AST) from the cultured supernatant of H9c2 cells, which were tested by enzyme-linked immune sorbent assay (ELISA) kits. In addition, it lessened the apoptotic rate as determined by a fluorescein isothiocyanate-annexin V/propidium iodide (FITC-AV/PI) double staining assay. It was also found that HA+GA might regulate the protein expression associated with the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Overall, the study demonstrated that HA+GA protected H9c2 cells against OGD-induced injury, and the signaling mechanism might be related to the PI3K/Akt signaling pathway.

Curcumin accelerates cutaneous wound healing via multiple biological actions: The involvement of TNF-α, MMP-9, α-SMA, and collagen

Curcumin, a constituent of the turmeric plant, has antitumor, anti-inflammatory, and antioxidative effects, but its effects on wound healing are unclear. We created back wounds in 72 mice and treated them with or without topical curcumin (0.2 mg/mL) in Pluronic F127 gel (20%) daily for 3, 5, 7, 9, and 12 days. Healing in wounds was evaluated from gross appearance, microscopically by haematoxylin and eosin staining, by immunohistochemistry for tumour necrosis factor alpha and alpha smooth muscle actin, and by polymerase chain reaction amplification of mRNA expression levels. Treatment caused fast wound closure with well-formed granulation tissue dominated by collagen deposition and regenerating epithelium. Curcumin increased the levels of tumour necrosis factor alpha mRNA and protein in the early phase of healing, which then decreased significantly. However, these levels remained high in controls. Levels of collagen were significantly higher in curcumin-treated wounds. Immunohistochemical staining for alpha smooth muscle actin was increased in curcumin-treated mice on days 7 and 12. Curcumin treatment significantly suppressed matrix metallopeptidase-9 and stimulated alpha smooth muscle levels in tumour necrosis factor alpha-treated fibroblasts via nuclear factor kappa B signalling. Thus, topical curcumin accelerated wound healing in mice by regulating the levels of various cytokines.

The Problem of Curcumin and Its Bioavailability: Could Its Gastrointestinal Influence Contribute to Its Overall Health-Enhancing Effects?

Curcumin, from the spice turmeric, exhibits anti-inflammatory, antioxidant, anticancer, antiviral, and neurotrophic activity and therefore holds promise as a therapeutic agent to prevent and treat several disorders. However, a major barrier to curcumin's clinical efficacy is its poor bioavailability. Efforts have therefore been dedicated to developing curcumin formulations with greater bioavailability and systemic tissue distribution. However, it is proposed in this review that curcumin's potential as a therapeutic agent may not solely rely on its bioavailability, but rather its medicinal benefits may also arise from its positive influence on gastrointestinal health and function. In this review, in vitro, animal, and human studies investigating the effects of curcumin on intestinal microbiota, intestinal permeability, gut inflammation and oxidative stress, anaphylactic response, and bacterial, parasitic, and fungal infections are summarized. It is argued that positive changes in these areas can have wide-ranging influences on both intestinal and extraintestinal diseases, and therefore presents as a possible mechanism behind curcumin's therapeutic efficacy.

Hepatocellular uptake of cyclodextrin-complexed curcumin during liver preservation: A feasibility study

The increasing demand for donor organs and the decreasing organ quality is prompting research toward new methods to reduce ischemia reperfusion injury (IRI). Several strategies have been proposed to protect preserved organs from this injury. Before curcumin/dextrin complex (CDC), a potent antioxidant and anti-inflammatory agent, can be used clinically we need to better understand the intracellular uptake under hypothermic conditions on a rat model of liver donation after circulatory death (DCD) and brain death (DBD). To be able to use the fluorescence of CDC for quantification the stability of CDC in different preservation solutions at 4°C or 37°C was investigated. Livers from Wistar rats were procured after being flushed-out through the portal vein using CDC-enriched preservation solutions and stored at 4°C for variable periods. The CDC signal was stable in different preservation solutions over a period of 4 h and allowed the rapid and lasting uptake of curcumin into cells. After 4 h of preservation, CDC was no longer visible microscopically, and HPLC analysis showed very low to non-detectable tissue levels of CDC, proving metabolization during preservation. However, the distribution of CDC was not affected by warm ischemia damage (p = 0.278) nor by flushing the livers before or after 4 h of cold storage and without a warm preflush. Finally, curcumin reduced oxidative stress, lowered histological injury and did not change gene expression after WI/cold storage. Therefore, the use of CDC flush solution for the initial organ flush can offer a promising approach to the enhancement of liver preservation and the maintenance of its quality.

Chitosan-based polymer hybrids for thermo-responsive nanogel delivery of curcumin

The purpose of this study is to design and develop thermoresponsive nano-sized hydrogel particles from a natural polymer, chitosan, as smart material platforms for curcumin delivery. Chitosan was used as the backbone material to be grafted with poly-(N-isopropylacrylamide) (pNIPAM) using an EDC/NHS coupling reaction. The conjugated products were characterized by ¹H NMR and TGA. Chitosan-grafted pNIPAM (CS-g-pN) nanogels were prepared by a sonication method. The loading of curcumin into the CS-g-pN nanogels was achieved using an incubation method. Size, morphology of nanogels, amounts of curcumin loaded to the nanogels and cellular uptake were investigated by DLS, TEM, fluorescent spectroscopy and confocal microscopy techniques, respectively. A CellTiter-Blue^® cell viability assay was performed in NIH-3T3 and HeLa cells to assess the safety while MTT assay was carried out in MDA-231, Caco-2, HepG2, and HT-29 cells for determining cytotoxic effects. Results showed that CS-g-pN with 3-60% degree of modification were simply assembled into spherical nanogel particles with submicron sizes, in which curcumin was encapsulated. The thermoresponsive behavior of each CS-g-pN nanogel formulation differed due to the grafted pNIPAM length and density. The CS-g-pN nanogel formulations were non-toxic towards NIH-3T3 and HeLa cells. Each curcumin-loaded CS-g-pN nanogel formulation could be up taken into NIH-3T3 cell lines and showed the dose-dependent cytotoxicity against tested cell lines. Successful development of this curcumin-loaded nanogel will lead to advanced materials that can be functionalized and optimized for targeted therapy and controlled delivery of small molecules and/or biomolecules for biomedical applications.

MicroRNA-378 protects against intestinal ischemia/reperfusion injury via a mechanism involving the inhibition of intestinal mucosal cell apoptosis

Intestinal ischemia/reperfusion (I/R) injury remains a major clinical event and contributes to high morbidity and mortality rates, but the underlying mechanisms remain elusive. Recent studies have demonstrated that microRNAs (miRNAs) have important roles in organ I/R injury, but the changes and potential roles of miRNAs in intestinal I/R-induced intestinal injury are unclear. This study was designed to analyze the miRNA expression profiles in intestinal mucosa after I/R injury and to explore the role of target miRNA during this process. Using miRNA microarray analysis, we found changes of 19 miRNAs from the expression profile of miRNAs in a mouse model of intestinal I/R and further verified them by RT-qPCR. Here, we report that miR-378 is one of the markedly decreased miRNAs and found the putative target mRNA that is linked to cell death after applying the TargetScan, miRanda, CLIP-Seq and miRDB prediction algorithms. Our results show that the overexpression of miR-378 significantly ameliorated intestinal tissue damage in wild-type and transgenic mice and oxygen glucose deprivation/reperfusion-challenged IEC-6 cell injury. Moreover, miR-378 overexpression reduced intestinal epithelial cell apoptosis in both in vivo and in vitro ischemic models and attenuated cleaved caspase-3 expression. Collectively, our results revealed that the suppression of caspase-3 activation by miRNA-378 overexpression may be involved in the protective effects of intestinal ischemic damage. MiRNA-378 may serve as a key regulator and therapeutic target in intestinal I/R injury.

Short-term dietary curcumin supplementation reduces gastrointestinal barrier damage and physiological strain responses during exertional heat stress

Szymanski MC, Gillum TL, Gould LM, Morin DS, Kuennen MR. Short-term dietary curcumin supplementation reduces gastrointestinal barrier damage and physiological strain responses during exertional heat stress. J Appl Physiol 124: 330-340, 2018. First published September 21, 2017; doi: 10.1152/japplphysiol.00515.2017 .-This work investigated the effect of 3 days of 500 mg/day dietary curcumin supplementation on gastrointestinal barrier damage and systems-physiology responses to exertional heat stress in non-heat-acclimated humans. Eight participants ran (65% V̇o_2max) for 60 min in a Darwin chamber (37°C/25% relative humidity) two times (Curcumin/Placebo). Intestinal fatty acid-binding protein (I-FABP) and associated proinflammatory [monocyte chemoattractant protein-1, tumor necrosis factor-α (TNF-α), interleukin-6] and anti-inflammatory [interleukin-1 receptor antagonist (IL-1RA), interleukin-10 (IL-10)] cytokines were assayed from plasma collected before (Pre), after (Post) and 1 (1-Post) and 4 (4-Post) h after exercise. Core temperature and HR were measured throughout exercise; the physiological strain index (PSI) was calculated from these variables. Condition differences were determined with 2-way (condition × time) repeated-measures ANOVAs. The interaction of condition × time was significant ( P = 0.05) for I-FABP and IL-1RA. Post hoc analysis indicated I-FABP increased more from Pre to Post (87%) and 1-Post (33%) in Placebo than in Curcumin (58 and 18%, respectively). IL-1RA increased more from Pre to 1-Post in Placebo (153%) than in Curcumin (77%). TNF-α increased ( P = 0.01) from Pre to Post (19%) and 1-Post (24%) in Placebo but not in Curcumin ( P > 0.05). IL-10 increased ( P < 0.01) from Pre to Post (61%) and 1-Post (42%) in Placebo not in Curcumin ( P > 0.05). The PSI, which indicates exertional heatstroke risk, was also lower ( P < 0.01) in Curcumin than Placebo from 40 to 60 min of exercise. These data suggest 3 days curcumin supplementation may improve gastrointestinal function, associated cytokines, and systems-level physiology responses during exertional heat stress. This could help reduce exertional heatstroke risk in non-heat-acclimated individuals. NEW & NOTEWORTHY Exercise-heat stress increases gastrointestinal barrier damage and risk of exertional heatstroke. Over the past decade at least eight different dietary supplements have been tested for potential improvements in gastrointestinal barrier function and systems-level physiology responses during exercise-heat stress. None have been shown to protect against both insults simultaneously. In this report 3 days of 500 mg/day dietary curcumin supplementation are shown to improve gastrointestinal barrier function, associated cytokine responses, and systems-level physiology parameters. Further research is warranted.

Protective Effect of Camellia Oil (Camellia oleifera Abel.) against Ethanol-Induced Acute Oxidative Injury of the Gastric Mucosa in Mice

Camellia oil, a common edible oil in Taiwan and China, has health effects for the gastrointestinal tract in folk medicine, and it contains abundant unsaturated fatty acids and phytochemicals. However, the preventive effect of camellia oil on ethanol-induced gastric ulcers remains unclear. This study was aimed to evaluate the preventive effect of camellia oil on ethanol-induced gastric injury in vitro and in vivo as well as its mechanisms of action. In an in vitro study, our results showed that pretreatment of RGM-1 cells with camellia oil enhanced the migration ability as well as increased heat shock protein expression and reduced apoptotic protein expression. In animal experiments, mice pretreated with camellia oil effectively showed improved ethanol-induced acute injury of the gastric muscosa and oxidative damage through the enhancement of antioxidant enzyme activities and heat shock protein and PGE₂ production, as well as the suppression of lipid peroxidation, apoptosis-related proteins, pro-inflammatory cytokines, and NO production. Histological injury score and hemorrhage score in ethanol-induced gastric mucosal damage dramatically elevated from the control group (0.00 ± 0.0) to 3.40 ± 0.7 and 2.60 ± 0.5, respectively. However, treatments with camellia oil or olive oil (2 mL/kg bw) and lansoprazole (30 mg/kg bw) showed significant decreases in elevation of injury score and hemorrhage score (p < 0.05). Therefore, camellia oil has the potential to ameliorate ethanol-induced acute gastric mucosal injury through the inhibition of inflammation and oxidative stress.

Lamotrigine decreases MRP8 and IL-7 in rat models of intractable epilepsy secondary to focal cortical dysplasia

The aim of the present study was to examine the effect of lamotrigine and the expression of myeloid-related protein 8 (MRP8) and interleukin-7 (IL-7) in the treatment of focal cortical dysplasia with secondary intractable epilepsy. In this study, rats with focal cortical dysplasia with secondary intractable epilepsy (constructed by our laboratory) were selected and used for experimentation, 21-day Sprague-Dawley rats were randomly divided into the control group (38 rats), the observation group I (39 rats), and the observation group II (38 rats). Rats in the observation group I received daily intraperitoneal injection of 0.02 mg/kg lamotrigine, and those in the observation group II and the control group received daily intraperitoneal injection of 0.02 mg/kg normal saline. Expression quantities of MRP8 and IL-7 in the hippocampus sample tissues of mice in the control group, observation group I, and observation group II were measured via fluorescence quantitative polymerase chain reaction assay, western blot analysis, enzyme-linked immunosorbent assay, and immunohistochemistry 48 h later. MRP8 and IL-7 gene mRNA levels of the control group, the observation group I and the observation group II had no significant differences (P>0.05). The expression quantity on the protein level of MRP8 and IL-7 showed no significant differences (P>0.05) between the observation group I (7.91±1.3, 3.86±0.38) and the control group (7.52±1.03, 3.62±0.29). The expression quantity of MRP8 and IL-7 showed significant differences (P<0.05) between observation group II (27.47±1.13, 19.45±0.48) and observation group I (7.91±1.3, 3.86±0.38). It was found that MRP8 and IL-7 were focused on the nerve cell membrane of hippocampus of rats in the observation group by immunohistochemistry experiments. In conclusion, the results from the present study show that lamotrigine can be used to treat rats with focal cortical dysplasia with secondary intractable epilepsy by reducing the expression levels of MRP8 and IL-7 in the body, providing a new therapeutic target to the follow-up treatment of focal cortical dysplasia with secondary intractable disease.

SIRTUIN 1 ACTIVATOR SRT1720 PROTECTS AGAINST ORGAN INJURY INDUCED BY INTESTINAL ISCHEMIA-REPERFUSION

Intestinal ischemia-reperfusion (I/R) occurs in various clinical situations and causes local and remote organ injury, especially in the lungs, leading to significant morbidity and mortality. The maintenance of mitochondrial biogenesis is essential for cell survival and is regulated in part by sirtuin 1 (SIRT1), an energy-sensing enzyme. We hypothesized that SIRT1 activation with SRT1720 would reduce local and remote organ injury after intestinal I/R. Intestinal I/R was induced by the occlusion of the superior mesenteric artery of adult male C57BL/6 mice for 45 min, followed by reperfusion for 4 h. SRT1720 or vehicle was injected intravenously at the time of reperfusion. Blood, small intestine, and lung tissues were collected for analysis. The SRT1720 treatment of I/R mice resulted in a 57% increase in protein levels of succinate dehydrogenase, an index of mitochondrial mass, and a 120% increase in messenger RNA levels of mitochondrial transcription factor A, a marker for mitochondrial biogenesis. The microscopic architecture and apoptosis of the gut tissue was improved in the SRT1720-treated I/R mice. SRT1720 decreased intestinal messenger RNA levels of tumor necrosis factor-α by 60% and inducible nitric oxide synthase to baseline after I/R. Systemic inflammation, as determined by serum interleukin-6, was reduced in treated mice. Lung injury, as measured by histological architecture and myeloperoxidase activity, and lung apoptosis were also improved after the SRT1720 treatment. SRT1720 preserved mitochondrial biogenesis and mass, leading to inhibition of inflammation and oxidative stress, thereby protecting against intestinal I/R-induced injury. Thus, the SIRT1-mediated pathway is a promising target for the treatment of intestinal I/R injury.

Curcumin protects against the intestinal ischemia-reperfusion injury: involvement of the tight junction protein ZO-1 and TNF-α related mechanism

Present study aimed to investigate the eff ect of curcumin-pretreatment on intestinal I/R injury and on intestinal mucosa barrier. Thirty Wistar rats were randomly divided into: sham, I/R, and curcumin groups (n=10). Animals in curcumin group were pretreated with curcumin by gastric gavage (200 mg/kg) for 2 days before I/R. Small intestine tissues were prepared for Haematoxylin & Eosin (H&E) staining. Serum diamine oxidase (DAO) and tumor necrosis factor (TNF)-α levels were measured. Expression of intestinal TNF-α and tight junction protein (ZO-1) proteins was detected by Western blot and/or immunohistochemistry. Serum DAO level and serum and intestinal TNF-α leves were signifi cantly increased after I/R, and the values were markedly reduced by curcumin pretreatment although still higher than that of sham group (p<0.05 or p<0.001). H&E staining showed the significant injury to intestinal mucosa following I/R, and curcumin pretreatment signifi cantly improved the histological structure of intestinal mucosa. I/R insult also induced significantly down-regulated expression of ZO-1, and the eff ect was dramatically attenuated by curcumin-pretreatment. Curcumin may protect the intestine from I/R injury through restoration of the epithelial structure, promotion of the recovery of intestinal permeability, as well as enhancement of ZO-1 protein expression, and this eff ect may be partly attributed to the TNF-α related pathway.

Protective Effects of Curcumin on Intestinal Damage in Cholestatic Rats

BACKGROUND

The aim of this study was to evaluate the possible protective effects of curcumin on oxidative stress, cell proliferation, and apoptosis in the rat intestinal mucosa after bile duct ligation (BDL).

METHODS

A total of 18 male Sprague Dawley rats were divided into three groups: sham control, BDL and BDL+curcumin; each group contain six animals. The rats in the curcumin-treated group were given curcumin (100 mg/kg) once a day orally for 14 days, starting 3 days prior to BDL operation. Following 14 days of treatment, all the animals were decapitated and intestinal tissues samples obtained for biochemical and histopathological investigation.

RESULTS

Curcumin treatment was found to significantly lower elevated tissue malondialdehyde levels and myeloperoxidase activity, and to raise reduced glutathione levels in intestinal tissues samples. BDL caused severe histopathological injury, including shortening of the villi, loss of villous epithelium, multiple erosions, inflammatory cell infiltration, necrosis, and hemorrhage into the intestinal wall. Curcumin treatment significantly attenuated the severity of intestinal injury, with inhibition of BDL-induced apoptosis and cell proliferation.

CONCLUSION

Curcumin treatment has a protective effect against intestinal damage induced by BDL. The ability of curcumin treatment is to inhibit BDL-induced oxidative stress, apoptosis, and cell proliferation.

Curcumin inhibits autophagy and apoptosis in hypoxia/reoxygenation-induced myocytes

Primary percutaneous coronary intervention, or thombolytic therapy, provides effective myocardial blood reconstruction in patients with acute myocardial infarction to reduce acute myocardial ischemic injury. However, reperfusion can itself induce cardiomyocyte death, termed myocardial reperfusion injury (I/R). Hypoxia/reoxygenation (H/R) induces apoptosis and excessive autophagy among cardiomyocytes, leading to cell death. The present study investigated the effect of curcumin, a natural extract from Curcuma longa, on these two cellular processes in H9c2 myocytes. The levels of cellular apoptosis and autophagy were found to be upregulated in the H9c2 myocytes during H/R and were correlated with a reduced rate of cell survival. However, curcumin significantly suppressed the levels of H/R‑induced apoptosis (expression of annexin V) and autophagy (LC3B‑II/LC3B‑I ratio) in the H9c2 myocytes and promoted cell survival. Additionally, the expression of B‑cell lymphoma 2 (Bcl‑2) was significantly downregulated and the expression levels of Bcl‑2‑associated X protein, beclin‑1, Bcl‑2/adenovirus E1B 19 kDa interacting protein 3 (BNIP3) and silent information regulation 1 (SIRT1) were significantly upregulated in myocytes following H/R injury. These effects on the expression of these proteins were reversed by curcumin treatment. These findings suggested that the protective effect of curcumin against H/R injury in the H9c2 myocytes was through the inhibition of apoptosis and autophagy by inducing the expression of Bcl‑2 and inhibiting the expression levels of Bax, beclin‑1, BNIP3 and SIRT1. Therefore, curcumin may offer a promising therapeutic approach for the treatment of cardiomyocyte injury resulting from I/R.

Icariin protects against intestinal ischemia-reperfusion injury

BACKGROUND

This study investigated the role of Sirtuin 1 (SIRT1)/forkhead box O3 (FOXO3) pathway, and a possible protective function for Icariin (ICA), in intestinal ischemia-reperfusion (I/R) injury and hypoxia-reoxygenation (H/R) injury.

MATERIALS AND METHODS

Male Sprague-Dawley rats were pretreated with different doses of ICA (30 and 60 mg/kg) or olive oil as control 1 h before intestinal I/R. Caco-2 cells were pretreated with different concentrations of ICA (25, 50, and 100 μg/mL) and then subjected to H/R-induced injury.

RESULTS

The in vivo results demonstrated that ICA pretreatment significantly improved I/R-induced tissue damage and decreased serum tumor necrosis factor α and interleukin-6 levels. Changes of manganese superoxide dismutase, Bcl-2, and Bim were also reversed by ICA, and apoptosis was reduced. Importantly, the protective effects of ICA were positively associated with SIRT1 activation. Increased SIRT1 expression, as well as decreased acetylated FOXO3 expression, was observed in Caco-2 cells pretreated with ICA. Additionally, the protective effects of ICA were abrogated in the presence of SIRT1 inhibitor nicotinamide. This suggests that ICA exerts a protective effect upon H/R injury through activation of SIRT1/FOXO3 signaling pathway. Accordingly, the SIRT1 activator resveratrol achieved a similar protective effect as ICA on H/R injury, whereas cellular damage resulting from H/R was exacerbated by SIRT1 knockdown and nicotinamide.

CONCLUSIONS

SIRT1, activated by ICA, protects intestinal epithelial cells from I/R injury by inducing FOXO3 deacetylation both in vivo and in vitro These findings suggest that the SIRT1/FOXO3 pathway can be a target for therapeutic approaches intended to minimize injury resulting from intestinal dysfunction.

Effect of sevoflurane on tissue permeability of lung ischemia-reperfusion injury in rats

OBJECTIVE

To investigate the effect of sevoflurane on tissue permeability of lung ischemia-reperfusion injury (LIRI) in rats.

METHODS

A total of 45 wistar rats were randomly divided into 3 groups I, II, III. Modified Eppinger method was adopted to establish the rat lung ischemia-reperfusion injury model. Group I served as the control group, group III as ischemia reperfusion group, group III as sevoflurane ischemia-reperfusion group. Blood gas index, lung permeability index (LPI) change, lung tissue pathology change and lung water content were observed and compared between groups of rats at different time points.

RESULTS

During ischemia reperfusion, all rats kept balance of the MAP during different time points, SPO2 of group II and III decreased significantly than I group (P<0.05); after reperfusion lung permeability index in Group II and III was higher than the control group significantly (P<0.05), 120 min after reperfusion LPI change and injury of group III was significantly lower than II group (P<0.05); interstitial and alveolar cavity effusion in of group III were lower than that of group II.

CONCLUSIONS

Sevoflurane pretreatment can reduce the lung tissue permeability, and LIRI plays a protective role in LIRI.

Impact of alanyl-glutamine dipeptide on proliferative and inflammatory changes in jejunal mucosa after acute mesenteric ischemia

PURPOSE

The aim of our study was to determinate the impact of dipeptide (alanyl-glutamine) administration on inflammatory and proliferative changes in jejunal mucosa after acute mesenteric ischemia.

METHODS

Male Wistar rats (n=30) were divided into three groups: ischemia/reperfusion (IR) group which undergoes 60min of mesenteric ischemia and 1 or 24h of reperfusion (IR1, IR24, n=12). Groups with dipeptide administration (D+IR1, D+IR24, Dipeptiven con inf., i.v., 0.75 g/kg) prior to IR injury were followed by 1 and 24h of reperfusion. At the end of reperfusion period jejunal bioptic samples were obtained for histological (H&E), histochemical (Alcian blue) and immunohistochemical (anti-PCNA, anti-MPO) evaluations.

RESULTS

Our results pointed out a significant (p<0.001) increase of histopathological injury score in IR1 group compared to D+IR1 group. Immunohistochemical evaluation showed that MPO-positivity was significantly increased in IR groups after 1 (p<0.001) as well as 24h of reperfusion (p<0.01) compared to dipeptide pretreated groups. Proliferative/reparatory rate was assessed using anti-PCNA antibody and showed a significant increase (p<0.01) in PCNA cell positivity in lamina propria in dipeptide treated group compared to IR group.

CONCLUSION

In conclusion we may suggest that administration of alanyl-glutamine dipeptide prior to IR injury may help to protect small intestine and its mucous membrane integrity against insult such as intestinal ischemic/reperfusion injury presents.

Effect of simulated transport stress on the rat small intestine: A morphological and gene expression study

The present study investigated the effects of simulated transport stress on morphology and gene expression in the small intestine of laboratory rats. Sprague Dawley rats were subjected to 35°C and 0.1×g on a constant temperature shaker for physiological, biochemical, morphological and microarray analysis before and after treatment. The treatment induced obvious stress responses with significant decreases in body weight (P<0.01), increases in rectal temperature, serum corticosterone (CORT), serum glucose (GLU), creatine kinase (CK) and lactate dehydrogenase (LDH) levels (P<0.01), as well as expression of Hsp27/70/90 mRNA (P<0.05; P<0.01). The rat jejunum was severely damaged and apoptotic after mimicking transport stress, which may mainly be related to cell death, oxidation reduction and hormone imbalance determined by microarray analysis. The bioinformatics analysis from the present study would provide insight into the potential mechanisms underlying transport stress-induced injury in the rat small intestine.

Magnesium lithospermate B improves myocardial function and prevents simulated ischemia/reperfusion injury-induced H9c2 cardiomyocytes apoptosis through Akt-dependent pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Magnesium lithospermate B (MLB), an active polyphenol acid of Radix Salviae Miltiorrhizae (Danshen), showed a wide range of pharmacological activities in cardiovascular diseases. However, its role in protection against ischemia/reperfusion injury in H9c2 cardiomyocytes has not been elucidated. This study was aimed to investigate the protective effect and potential molecular mechanisms of MLB on apoptosis in H9c2 cardiomyocytes in vitro.

MATERIALS AND METHODS

We tested cell viability, shortening amplitude, necrosis, apoptosis, and the expression levels of Akt, phosphorylated Akt, Bcl-2 and Bax after 2-h simulated ischemia and 24-h simulated reperfusion in H9c2 cardiomyocytes. We further observed the contractile function in hearts after they were subjected to global 30-min ischemia and 180-min reperfusion.

RESULTS

Pretreatment with MLB markedly increased cell viability and while reducing evidence of necrosis and apoptosis in H9c2 cardiomyocytes. In addition, the expression of Bcl-2 and Bax protein was modulated. The results also showed that MLB significantly increased phosphorylation of Akt and that this phosphorylation can be partially inhibited by phosphoinositide 3-kinase/Akt inhibitor. Furthermore, MLB improved MI/R-induced myocardial contractile function.

CONCLUSION

Our results showed that MLB prevents I/R-induced myocardial damage by reducing necrosis and apoptosis in H9c2 cardiomyocytes and improving myocardial function in rat hearts.

Protective effects of curcumin supplementation on intestinal ischemia reperfusion injury

The aim of this study was to investigate the effects curcumin on inflammation and oxidative stress markers in the intestinal ischemia reperfusion (IIR) injury induced rats. Rats were divided into four groups: sham (S), intestinal IR (IIR), curcumin plus sham (CS), and curcumin plus intestinal IR (CIIR). Curcumin was given 200 mg kg⁻¹ for 20 days. IIR was produced by 45 min of intestinal ischemia followed by a 120 min of reperfusion. Although interleukin-6 levels tended to increase in IIR group tumor necrosis factor-α levels were not different. Intestinal myeloperoxidase activity in CS group was lower than IIR group. In intestine and heart tissues, malondialdehyde levels in CS and CIIR groups were lower than S and IIR groups. Superoxide dismutase activity in CIIR group was higher than IIR group in intestine and lung tissues. Curcumin has a protective role against ischemia reperfusion injury.

Curcumin acts as a pro-oxidant inducing apoptosis via JNKs in the isolated perfused Rana ridibunda heart

Amphibians are known to better tolerate and endure adverse environmental conditions such as redox imbalances conferred by reactive oxygen species (ROS), compared to mammals. Interestingly, the exact adaptation strategies and signaling mechanisms mediating these effects have not been fully elucidated. Therefore, in the present study, we probed into the molecular response of the isolated perfused Rana ridibunda heart to curcumin, in the context of mitogen-activated protein kinases (MAPKs) phosphorylation patterns and apoptotic markers occurrence. In particular, this polyphenol was found to exert a pro-oxidant effect in our model and to significantly upregulate p38-MAPK and JNKs phosphorylation (thus activation). The early apoptosis observed, substantiated by poly(ADP-ribose) polymerase (PARP) cleavage, was established to be JNKs- and ROS-mediated, while no involvement of p38-MAPK was detected. Subsequently, the pro-oxidative activity of curcumin was confirmed to mimic H(2) O(2). Furthermore, NADPH oxidase as well as Na(+) /K(+) -ATPase were found to mediate JNKs phosphorylation as well as PARP proteolytic cleavage. Curcumin exerts pleiotropic actions, both beneficial and detrimental and is currently the subject of intense scientific research. Being a low-molecular-weight antioxidant, it is intriguing to investigate curcumin's role in redox homeostasis in the amphibian heart, under conditions that apparently favor its pro-oxidative properties. Comparative studies of its multifaceted role in different species may contribute to the clarification of the signaling mechanisms it triggers and the terminal physiological response it confers. Collectively, this is to our knowledge, the first time that the signal transduction pathways stimulated by curcumin have been assessed in a non-mammalian species.

Neuroprotective effect of curcumin on spinal cord in rabbit model with ischemia/reperfusion

BACKGROUND

Ischemic/reperfusion (I/R) injury of the spinal cord is a serious complication that can result from thoracoabdominal aortic surgery.

OBJECTIVE

To investigate the neuroprotective effect of curcumin against I/R injury in a rabbit model.

METHODS

A total of 36 rabbits were randomly divided into three groups: sham, I/R, and curcumin-treated group. Rabbits were subject to 30-min aortic occlusion to induce transient spinal cord ischemia. Neurological function was observed after reperfusion and spinal cord segment (L3-L5) was collected for histopathological evaluation. Malondialdehyde (MDA) and total superoxide dismutase (SOD) activity were also assayed.

RESULTS

Rabbits in I/R group were induced to paraplegia. While after 48-hour treatment, compared with I/R group, curcumin significantly improved neurological function, reduced cell apoptosis and MDA levels as well as increased SOD activity (P < 0.05).

CONCLUSIONS

The results suggest that curcumin, at least in an animal model, can attenuate transient spinal cord ischemic injury potentially via reducing oxidative damage, which may provide a novel approach in the treatment of spinal cord ischemic injury.

Keratinocyte growth factor improves epithelial structure and function in a mouse model of intestinal ischemia/reperfusion

Background

Intestinal ischemia/reperfusion (I/R) induces the desquamation of the intestinal epithelium, increases the intestinal permeability, and in patients often causes fatal conditions including sepsis and multiple organ failure. Keratinocyte growth factor (KGF) increases intestinal growth, although little is known about KGF activity on intestinal function after intestinal I/R. We hypothesized that KGF administration would improve the intestinal function in a mouse model of intestinal I/R.

Methods

Adult C57BL/6J mice were randomized to three groups: Sham, I/R group and I/R+KGF group. Mice were killed on day 5, and the small bowel was harvested for histology, wet weight, RNA and protein content analysis. Epithelial cell (EC) proliferation was detected by immunohistochemistry for PCNA, and apoptosis was determined by TUNEL staining. The expressions of Claudin-1 and ZO-1 were detected by immunohistochemistry. Epithelial barrier function was assessed with transepithelial resistance (TER).

Results

KGF significantly increased the intestinal wet weight, contents of intestinal protein and RNA, villus height, crypt depth and crypt cell proliferation, while KGF resulted in the decrease of epithelial apoptosis. KGF also stimulated the recovery of mucosal structures and attenuated the disrupted distribution of TJ proteins. Moreover, KGF attenuated the intestinal I/R-induced decrease in TER and maintained the intestinal barrier function.

Conclusion

KGF administration improves the epithelial structure and barrier function in a mouse model of intestinal I/R. This suggests that KGF may have clinical applicability.

Anti-inflammatory and antioxidant effects of infliximab on acute lung injury in a rat model of intestinal ischemia/reperfusion

The purpose of this study was to investigate the role of infliximab on acute lung injury induced by intestinal ischemia/reperfusion (I/R). A total of 30 male Wistar albino rats were divided into three groups: sham, I/R and I/R+ infliximab; each group contain 10 animals. Sham group animals underwent laparotomy without I/R injury. After I/R groups animals underwent laparotomy, 1 h of superior mesenteric artery ligation were followed by 1 h of reperfusion. In the infliximab group, 3 days before I/R, infliximab (3 mg/kg) was administered by intravenously. All animals were sacrificed at the end of reperfusion and lung tissues samples were obtained for biochemical and histopathological investigation in all groups. To date, no more biochemical and histopathological changes on intestinal I/R injury in rats by infliximab treatment have been reported. Infliximab treatment significantly decreased the elevated tissue malondialdehyde levels and increased of reduced superoxide dismutase, and glutathione peroxidase enzyme activities in lung tissues samples. Intestinal I/R caused severe histopathological injury including edema, hemorrhage, increased thickness of the alveolar wall and a great number of inflammatory cells that infiltrated the interstitium and alveoli. Infliximab treatment significantly attenuated the severity of intestinal I/R injury. Furthermore, there is a significant reduction in the activity of inducible nitric oxide synthase and arise in the expression of surfactant protein D in lung tissue of acute lung injury induced by intestinal I/R with infliximab therapy. It was concluded that infliximab treatment might be beneficial in acute lung injury, therefore, shows potential for clinical use. Because of its anti-inflammatory and antioxidant effects, infliximab pretreatment may have protective effects in acute lung injury induced by intestinal I/R.