Phototherapy with artificial light suppresses dextran sulfate sodium-induced colitis in a mouse model.

BACKGROUND AND AIM: Medical treatment for inflammatory bowel disease (IBD) requires chronic administration and causes side effects. Recently, anti-inflammatory effects of phototherapy were reported in animal models. The present study evaluated whether phototherapy improves dextran sulfate sodium (DSS)-induced colitis in a mouse model of IBD. METHODS: Mice were divided into four equal groups: Control, DSS, DSS + light low (LL), and DSS + light high (LH) groups. Normal fluorescent light intensity in the Control and DSS groups was 200 lux. Artificial light intensities were as follows: DSS + LL group, 1000 lux; DSS + LH group, 2500 lux. After administering phototherapy for 7 days, we evaluated disease activity index (DAI), histological score, colon length/weight, serum 1,25-dihydroxyvitamin D(3) level, and serum and colonic cytokines in the mice. RESULTS: DAI and histological scores were significantly lower in the DSS + LL group than in the DSS group (both, P < 0.05). Colon length and weight were significantly higher in the DSS + LL group than in the DSS group (both, P < 0.05). Serum interleukin (IL)-6, TNF-α, and IL-17 in the DSS + LL group were significantly lower, and serum and colonic IL-10 were significantly higher in the DSS + LL group than in the DSS group (all, P < 0.05). Serum 1,25-dihydroxyvitamin D(3) levels in the DSS + LH group were significantly increased compared with those in the DSS + LL and DSS groups. CONCLUSION: Artificial light phototherapy suppressed DSS-induced colitis in mice by suppression of pro-inflammatory cytokines and promotion of anti-inflammatory cytokines.

Bolus injection of newly synthesized vitamin E derivative ETS-GS for the treatment of acute severe ulcerative colitis in a mouse model. New vitamin E derivative for acute severe UC.

PURPOSE: Vitamin E with its antioxidant action has therapeutic effects on ulcerative colitis (UC), but use of vitamin E is limited because of its insolubility in water. We developed ETS-GS (γ-L-glutamyl-S-[2-[[[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltri-decyl)-2 H-1-benzopyran-6-yl]oxy]carbonyl]-3-oxo-3-[(2-sulfoethyl)amino]propyl]-L-cysteinylglycine sodium salt), a newly synthesized soluble vitamin E derivative with strong antioxidant action. We evaluated the therapeutic effects of bolus injection of ETS-GS on acute severe UC in a mouse model. METHODS: An animal model of acute severe UC was induced by feeding mice 5 % dextran sulfate sodium (DSS) for 5 days, followed by 1 % DSS on days 5-8, the experimental period. ETS-GS or saline was administered by subcutaneous bolus injection during the experimental period. We examined disease activity index (DAI) score, histological score, colon length, colon weight, and serum cytokines in the mice. RESULTS: The following results at day 8 in the DSS + ETS-GS group were significantly lower than those in the DSS + Saline group: DAI score, 2.6 ± 0.6 vs. 3.1 ± 0.5; histological score, 2.1 ± 1.0 vs. 3.1 ± 0.8; serum interleukin (IL)-6, 15 ± 9.4 vs. 39 ± 23 pg/ml; and keratinocyte-derived chemokine (KC), 122 ± 61 vs. 228 ± 66 pg/ml (P < 0.05). Colon length, colon weight, and serum IL-10 in the DSS + ETS-GS group were significantly higher than those in the DSS + Saline group (88 ± 12 vs. 75 ± 5.7 mm, 0.48 ± 0.09 vs. 0.38 ± 0.05 g, and 55 ± 18 vs. 31 ± 10 pg/ml, respectively; P < 0.05). CONCLUSIONS: Bolus injection of ETS-GS may be one therapeutic modality for acute severe UC. Its effects are associated with suppression of serum IL-6 and serum KC and promotion of serum IL-10.

Window current through the T-type Ca2+ channel triggers the mechanism for cellular apoptosis via mitochondrial pathways.

We hypothesized that Ca(2+) entry through the window T-type Ca(2+) current causes apoptosis. To test this hypothesis, we transfected human embryonic kidney (HEK) 293 cells to express recombinant Cav3.2 T-type Ca(2+) channels (hereafter called HEK-Cav3.2 cells). After incubation in media containing a high concentration (7.2 mM) of Ca(2+), intracellular Ca(2+) levels increased in HEK-Cav3.2 cells without electrical stimulation but not in untransfected HEK293 cells. In quiescent HEK-Cav3.2 cells exposed to high Ca(2+) media, apoptosis, as indicated by the appearance of hypodiploid cells, loss of mitochondrial transmembrane potential, and activation of caspases-3 and -9 was observed, while caspase-8 was not activated. These apoptosis-associated changes were blunted by pretreatment with the R(-)-isomer of efonidipine, a selective blocker of T-type Ca(2+) channels. High Ca(2+) did not induce apoptosis in untransfected HEK293 cells. Our findings show that Ca(2+) entry through the steady-state window current of T-type Ca(2+) channels causes apoptosis via mitochondrial pathways, and suggests that T-type Ca(2+) channels may be novel therapeutic targets for several diseases associated with abnormal apoptosis.

Should nicorandil infusion be adapted in dialysis-dependent patients undergoing continuous renal replacement therapy after cardiac surgery?

In this report, we studied whether plasma concentration of nicorandil is maintained effectively and safely in dialysis-dependent patients with stage 5 chronic kidney disease (CKD5D) undergoing continuous renal replacement therapy (CRRT). Participants consisted of 10 patients undergoing CRRT after cardiac surgery. CRRT was performed with an effluent flow rate of either 600 mL/h (low-flow group; n = 5) or 1800 mL/h (high-flow group; n = 5). Nicorandil was infused intravenously at 0.1 mg/kg/h for more than 15 h starting 8 h before and 7 h after the start of CRRT. Plasma nicorandil concentrations were measured from arterial blood lines 1 h before and 7 h after CRRT initiation. Nicorandil clearance by CRRT was also calculated 1 h after CRRT initiation. Nicorandil plasma concentrations before and 7 h after CRRT initiation were 68.0 ng/mL and 74.6 ng/mL, respectively. Nicorandil clearance 1 h after CRRT initiation was 20.2 mL/min. Increasing the effluent flow rate from 600 mL/h to 1800 mL/h tended to increase nicorandil clearance. When nicorandil was infused intravenously during CRRT at 0.1 mg/kg/h in patients with CKD5D, plasma nicorandil concentrations were maintained within an effective concentration range.

[Relationships between damage-associated molecular patterns and organ injury].

Recently studies have demonstrated that cell components called damage-associated molecular patterns (DAMPs) are secreted from cells in response to inflammation and organ injury. While DAMPs are maintained within the cell under normal conditions, they are secreted in response to systemic or chronic inflammation. DAMPs are recognized by pattern recognition receptors (PRRs) such as Toll-like receptor (TLR) and receptor for advanced glycation end products (RAGE). DAMPs also induce the phosphorylation of various intracellular proteins and activate NF-kappaB signaling. This induces an inflammatory response via cytokine production and activation of macrophages and dendritic cells. In essence, DAMPs alert the immune system to danger. Some DAMPs are considered therapeutic targets for acute systemic inflammation (e.g., sepsis). Indeed, anti-HMGB1 and anti-histone antibodies attenuated the inflammatory response and organ injury in a systemic inflammation model. Anti-RAGE antibodies were also shown to have beneficial effects in an animal inflammation model. These findings suggest that DAMPs may serve as novel therapeutic targets against severe systemic inflammation as well. We anticipate that in the near future, anti-DAMP therapy may become more widespread in the clinical setting.

Alternate day calorie restriction improves systemic inflammation in a mouse model of sepsis induced by cecal ligation and puncture.

BACKGROUND: Calorie restriction (CR) exerts cytoprotective effects by up-regulating survival factors, such as mammalian target of rapamycin (mTOR), sirtuin, and peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α). These survival factors have well-established roles in attenuating the inflammatory response. However, it is unclear whether CR affects sepsis-related inflammation. The purpose of this study was to determine whether CR affects sepsis-induced inflammation in a cecal ligation and puncture (CLP)-induced mouse model of sepsis. METHODS: Male C57BL/6N mice underwent alternate day calorie restriction or normal feeding for 8 d before CLP-induced sepsis. After induction of sepsis, liver and lung histopathology and serum levels of cytokines and survival factors were assessed. RESULTS: Serum cytokine and high mobility group box protein 1 (HMGB1) levels were lower in animals that underwent alternate day calorie restriction compared with normally-fed mice after CLP. Alternate day calorie restriction also increased levels of sirtuin, PGC-1α, and mTOR. While 80% of mice in the CLP group died within 48 h after undergoing CLP, 50% of mice died in the ACR + CLP group (P < 0.05). CONCLUSION: Alternate day calorie restriction decreased mortality in a mouse model of sepsis. In addition to attenuated organ injury, a significant reduction in cytokine and HMGB1 levels was observed. These findings suggest that alternative day calorie restriction may reduce excessive inflammation.

Human atrial natriuretic peptide attenuates renal ischemia-reperfusion injury.

BACKGROUND: Acute kidney injury (AKI) is common in the intensive care unit, and one of its primary causes is renal ischemia-reperfusion (I/R) injury. Human atrial natriuretic peptide (hANP) exerts various pharmacologic effects, including renal protection. In the present study, we evaluated the renal protective effect of hANP in a rat model of renal I/R. MATERIALS AND METHODS: Male Wistar rats were divided into three groups that received the following treatments: induction of renal I/R (I/R group); continuous intravenous injection of hANP followed 30 min later by induction of renal I/R (hANP+I/R group); and sham treatment (control group). Rats were sacrificed after 60 min of ischemia and 24 h of reperfusion or sham treatment. To evaluate the renal protective effects if hANP, serum blood urea nitrogen (BUN) and creatinine (Cre) concentrations were determined, kidneys were histologically assessed, and serum biomarkers of oxidative stress were evaluated. In addition, antimycin A (AMA)-stimulated RAW264.7 cells were treated with hANP to assess its antioxidant effects. RESULTS: Serum BUN and Cre levels were elevated in the I/R group; however, these increases were significantly inhibited in the hANP + I/R group. Similarly, kidney tissue damage observed in the I/R group was attenuated in the hANP + I/R group. In vitro, AMA-stimulated cells treated with hANP showed reduced reactive oxygen species activity compared to cells treated with AMA alone. CONCLUSIONS: Our findings indicate that hANP may be effective in the treatment of various types of I/R injuries.

Age-dependent responses to renal ischemia-reperfusion injury.

BACKGROUND: The incidence of acute kidney injury (AKI) in the elderly population has steadily increased in recent years. Functional recovery after AKI is also impaired in the elderly; however, the mechanism underlying these age-related differences is not well understood. In the present study, we assessed kidney morphology, function, and oxidative stress in young and aged rats after renal ischemia and reperfusion. MATERIALS AND METHODS: Young (6- to 7-wk-old) and aged (60- to 65-wk-old) male Wistar rats were divided into four groups based on age and treatment: renal ischemia-reperfusion in young rats (young IR); renal ischemia-reperfusion in aged rats (aged IR); sham treatment in young rats (young control), and sham treatment in aged rats (aged control). Rats were sacrificed 24 h after treatment, serum blood urea nitrogen (BUN) and creatinine (Cre) concentrations were determined, and kidney tissue histology and 8-hydroxydeoxyguanosine (8-OHdG) levels were evaluated. RESULTS: After ischemia-reperfusion, serum BUN, and Cre levels were higher in aged rats than in young rats. Reperfusion-induced kidney damage and kidney tissue 8-OHdG levels were also more severe in the aged IR group. Moreover, plasma antioxidant potential was lower in aged IR rats than in young IR rats. CONCLUSIONS: Aged rats exhibited reduced antioxidant potential and increased oxidative stress after ischemia-reperfusion. Our findings demonstrate that aged rats experience more severe reperfusion-induced injuries compared with young rats.

New anthranilic acid derivative, EAntS-GS, attenuates Freund's complete adjuvant-induced acute pain in rats.

BACKGROUND: Acute and chronic pain commonly accompany various clinical conditions such as contusion, fracture, osteoarthritis, peripheral neuropathy, and postherpetic neuralgia. Recent studies have found that antioxidative drugs can have analgesic effects. The present study tested the hypothesis that a new anthranilic acid derivative, EAntS-GS, exerts antinociceptive effects on inflammatory pain in a rat model. METHODS: We induced subacute pain with a plantar injection of Freund's complete adjuvant (FCA) in Sprague-Dawley rats. EAntS-GS (1 mg/kg subcutaneous injection or 1% application) was administered every 12 h beginning 24 h after FCA administration, and the plantar test was used to determine its effect on pain. Levels of myeloperoxidase, inducible nitric oxide synthase (iNOS), and protease activated receptor 2 (PAR2) were measured to elucidate the mechanism of action of EAntS-GS. RESULTS: EAntS-GS significantly reduced FCA-induced pain and myeloperoxidase, iNOS, and PAR2 levels. Our findings suggest that the new anthranilic acid derivative, EAntS-GS, exerts antinociceptive effects, and that the mechanism involves iNOS and PAR2. CONCLUSION: We conclude that EAntS-GS should be considered a new therapeutic tool to treat acute and chronic pain.

The vitamin E derivative, ESeroS-GS, attenuates renal ischemia-reperfusion injury in rats.

BACKGROUND: Acute kidney injury (AKI), which occurs during renal transplantation and cardiovascular surgery, is a major clinical problem associated with high mortality, and has limited treatment options. Anti-inflammation therapy has been suggested to improve the course and outcome of AKI. In this study, we hypothesized that ESeroS-GS, a vitamin E derivative, inhibits cytokine production and prevents renal ischemia-reperfusion (I/R) injury in rats. METHODS: Rats received an intravenous infusion of ESeroS-GS or saline, and underwent experimentally-induced renal I/R injury or sham treatment. Rats were sacrificed after 60 min of ischemia and 24 h of reperfusion. To evaluate the renal protective effects of ESero-GS, renal function was examined, kidneys were histologically assessed, levels of myeloperoxidase (MPO) and serum cytokines were measured, and caspase 3/7 activity was determined. RESULTS: ESeroS-GS attenuated I/R-induced histologic alterations, reduced levels of MPO and serum BUN, Cre, TNF-α, and IL-6, and decreased caspase 3/7 activity in kidneys of rats subjected to renal I/R injury. CONCLUSIONS: ESeroS-GS attenuated renal injury after I/R by reducing serum cytokine levels. Our findings suggest that ESeroS-GS may have therapeutic potential against various human I/R conditions.

Removal of 17 cytokines, HMGB1, and albumin by continuous hemofiltration using a cellulose triacetate membrane: an ex vivo study.

BACKGROUND: Hemofiltration is often used to treat critically ill patients with renal failure and septic shock. Although hemofiltration has been reported to remove humoral mediators such as cytokines, most studies have investigated the removal of only limited kinds of cytokines. Here, we assessed the removal of 17 cytokines, HMGB1, and albumin by continuous hemofiltration (CHF) with a cellulose triacetate membrane (2.1 m(2) or 1.1 m(2)). METHODS: The subjects were six healthy volunteers. We collected 400 mL blood into containers with heparin. After adding 1 mg/mL lipopolysaccharide, the blood was incubated at 39°C for 12 h and then filtered through a closed hemofiltration circuit (1 or 2 L/h). Sixty and 240 min after beginning hemofiltration, samples were collected from the outlet (arterial) side, inlet (venous) side, and filtrate port. Blood levels of cytokines, HMGB1, and albumin were determined at each time point. RESULTS: Increasing the flow rate significantly increased cytokine clearance. Increasing the membrane area of the hemofilter significantly changed the sieving coefficient of only five cytokines (IL-1ß, IL-6, MCP-1, MIP-1ß, HMGB1). For many cytokines, the sieving coefficient did not decline during the 240-min CHF procedure. CONCLUSION: Although all 17 cytokines, HMGB1, and albumin were detected in the filtrate, the SC and clearance varied widely. For numerous cytokines, clearance increased with the higher filtration flow rate. We demonstrated that CHF removed many cytokines and HMGB1, but was inefficient at removing albumin.

New α-lipoic acid derivative, DHL-HisZn, ameliorates renal ischemia-reperfusion injury in rats.

BACKGROUND: Ischemia-reperfusion (I/R) occurs frequently in a variety of clinical settings, such as renal transplantation. In addition, I/R is a major cause of acute kidney injury (AKI). A recent study has reported that reactive oxygen species (ROS) are important mediators of AKI, suggesting that reducing ROS generation may prevent renal injury. The present study evaluated the ability of DHL-HisZn, a new α-lipoic acid derivative, to inhibit ROS generation and prevent renal I/R injury in rats. MATERIALS AND METHODS: Rats received an intravenous infusion of DHL-HisZn or saline, and then underwent experimentally induced renal I/R injury or sham treatment. Rats were sacrificed after 60 min of ischemia and 24 h of reperfusion. To evaluate the renal protective effects of DHL-HisZn, serum blood urea nitrogen (BUN) and creatinine (Cre) concentrations were determined, kidneys were histologically assessed, and malondialdehyde (MDA), a biomarker of oxidative stress, was evaluated. In addition, antimycin A (AMA)-stimulated RAW264.7 cells were treated with DHL-HisZn to assess its antioxidant effects in vitro. RESULTS: DHL-HisZn treatment attenuated I/R-induced histologic alterations, reduced serum levels of serum BUN and Cre, and decreased MDA levels in the kidneys of rats with renal I/R injury. Furthermore, DHL-HisZn decreased ROS levels in AMA-stimulated RAW264.7 cells. CONCLUSIONS: Our in vitro and in vivo findings suggest that DHL-HisZn may have therapeutic potential against various human I/R conditions.

The vitamin E derivative, EPC-K1, suppresses inflammation during hepatic ischemia-reperfusion injury and exerts hepatoprotective effects in rats.

BACKGROUND: An important component of postoperative management includes alleviation of hepatic ischemia-reperfusion (I/R) injury, which commonly results from liver surgery. EPC-K1 is a hydroxyl radical scavenger reported to have mitigating effects on I/R injury in many organs. This study evaluates the effects of EPC-K1 on hepatic I/R injury. MATERIALS AND METHODS: Rats were injected subcutaneously with either EPC-K1 (100 mg/kg) or saline. The hepatic artery and left branch of the portal vein were clamped for 45 min under general anesthesia. Indicators of liver function, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH), and of liver tissue damage were evaluated after 6h and 24h of reperfusion. Serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and high-mobility group box 1 (HMGB1) protein were measured, and apoptosis was quantified via caspase 3/7 activity and TUNEL assay. RESULTS: AST, ALT, and LDH levels increased significantly as a result of hepatic I/R injury, but were attenuated by EPC-K1 administration. Histologic findings revealed that normal structure of the hepatic parenchyma was maintained in rats pretreated with EPC-K1. TNF-α, IL-6, and HMGB1 levels rose significantly after reperfusion, together with activation of the inflammatory response. However, EPC-K1 administration suppressed levels of inflammatory markers and attenuated the inflammatory response. Moreover, EPC-K1 administration prevented apoptosis as determined by inhibition of caspase 3/7 activity and a decrease in apoptotic cells. CONCLUSIONS: Results demonstrate that EPC-K1 inhibits the inflammatory response and suppresses apoptosis during hepatic I/R injury. This suggests that EPC-K1 has hepatoprotective effects, and may be a valuable and novel therapeutic agent in the clinical setting.

Vitamin E derivative ETS-GS reduces liver ischemia-reperfusion injury in rats.

BACKGROUND: Ischemic liver injury is often the result of surgical procedures such as liver transplantation and hepatic resection. Liver damage occurs after reperfusion, leading to increased systemic inflammation. Recent studies have reported that vitamin E and glutathione can ameliorate ischemia-reperfusion (I/R) injury. In the present study, we evaluated the ability of a new vitamin E derivative, ETS-GS, to improve liver I/R injury. MATERIALS AND METHODS: Male Wistar received a subcutaneous injection of ETS-GS (10 mg/kg) or saline before experimentally-induced liver I/R injury or sham treatment. The rats were sacrificed after the 60-min ischemia and 24-h reperfusion. Histology and serum levels of cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-6, and high-mobility group box 1 (HMGB1) protein] and liver enzymes were determined to evaluate the protective effects of ETS-GS. RESULTS: We found that ETS-GS treatment attenuated I/R-induced histologic alterations, reduced levels of liver enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH). In addition, ETS-GS treatment decreased serum cytokine levels. CONCLUSIONS: Taken together, our results demonstrate that ETS-GS attenuates I/R injury in a rat model and suggests that ETS-GS may exert anti-inflammatory effects. Accordingly, ETS-GS may have therapeutic potential to treat various clinical conditions involving I/R injury.

[Severe hypotension and ventricular fibrillation during combined general and epidural anesthesia in a patient on major tranquilizers].

A 54-year-old man (height 155 cm, weight 49 kg) was scheduled for retroperitoneoscopic nephrectomy. He had a history of schizophrenia that had been controlled with propericiazine 10 mg and bromperidol 3 mg daily for 34 years. After induction of anesthesia, 1% mepivacaine 5 ml was administered via an epidural catheter. Blood pressure decreased 15 minutes later to 47/25 mmHg and heart rate dropped to 50 beats x min(-1). Ventricular fibrillation occurred despite titrated injection of ephedrine (40 mg total), phenylephrine (1 mg total), atropine (0.5 mg total), and rapid infusion of crystalloid and colloid solutions. Chest compression and defibrillation were required to restore spontaneous circulation. Surgery was cancelled and he was extubated 45 minutes later without any complications. These findings suggest that caution must be exercised when combining general and epidural anesthesia for patients on long-term major tranquilizers. In the event of refractory hypotension, the use of direct-acting vasoconstrictors such as noradrenaline or vasopressin should be considered.

[Reappraisal of current practice of preoperative fasting in Japan].

BACKGROUND: The American Society of Anesthesiologists (ASA) published a clinical practice guideline of preoperative fasting in 1999. A nationwide survey conducted in Japan in 2003 reveals that many hospitals have a much longer fasting period. We conducted a similar survey in three limited areas in Japan to assess the changes in fasting practice. METHODS: A written questionnaire for preoperative fasting was sent to 50 hospital in 3 prefectures. RESULTS: The duration of fasting for liquids tends to be shorter than those in the 2003 survey. The rates of application of the ASA guideline, however, are still low specifically in adults (4.2%), which is significantly lower than those in children (17.7%), or in infants (39.0%). The reasons for noncompliance are mainly due to organizational problems associated with scheduling of operation. Most hospitals aspire to have Japanese guideline about preoperative fasting periods. CONCLUSIONS: Longer preoperative fasting periods are still common practice in Japanese hospitals.

New lipoic acid derivative drug sodium zinc dihydrolipoylhistidinate prevents cardiac dysfunction in an isolated perfused rat heart model.

OBJECTIVE: Myocardial ischemia/reperfusion injury is a life-limiting condition. Reactive oxygen species are released upon reperfusion, resulting in damage to myocardial cells. Accordingly, antioxidant drugs have been shown to protect the myocardium against ischemia/reperfusion injury. The purpose of the present study was to determine the cardioprotective effects of the new lipoic acid-derivative drug sodium zinc dihydrolipoylhistidinate in a global ischemia isolated perfused rat heart model. DESIGN: Animals were randomly divided into five groups: 1) normal group, 2) control ischemia/reperfusion group, 3) high-dose sodium zinc dihydrolipoylhistidinate (1 ng/mL) plus ischemia/reperfusion group, 4) medium-dose sodium zinc dihydrolipoylhistidinate (0.1 ng/mL) plus ischemia/reperfusion group, or 5) low-dose sodium zinc dihydrolipoylhistidinate (0.01 ng/mL) plus ischemia/reperfusion group. SETTING: University medical center research laboratory. SUBJECTS: Male Sprague-Dawley rats weighing 250-300 g. MEASUREMENTS AND MAIN RESULTS: Hearts underwent ischemia/reperfusion after isolation with or without sodium zinc dihydrolipoylhistidinate treatment. We then conducted cardiac histopathology and transmission electron microscopy analyses and assessed cardiac function. In addition, we examined the effects of sodium zinc dihydrolipoylhistidinate on ischemia/reperfusion-induced mitochondrial dysfunction. We found that cardiac dysfunction and mitochondrial damage were significantly reduced after reperfusion by sodium zinc dihydrolipoylhistidinate treatment. However, only rats treated with high-dose sodium zinc dihydrolipoylhistidinate showed improved cardiac function. Furthermore, treatment with sodium zinc dihydrolipoylhistidinate significantly improved mitochondrial function in vitro. CONCLUSIONS: These findings suggest that sodium zinc dihydrolipoylhistidinate attenuates ischemia/reperfusion-induced myocardial dysfunction in rats. Furthermore, sodium zinc dihydrolipoylhistidinate exerted cardioprotective effects via preservation of mitochondrial function. Taken together, our results strongly support the potential therapeutic role of sodium zinc dihydrolipoylhistidinate in the treatment of ischemia/reperfusion injury.

The antioxidant EPC-K1 attenuates renal ischemia-reperfusion injury in a rat model.

BACKGROUND: Acute kidney injury (AKI) occurs frequently in the intensive care unit. A primary cause is renal ischemia/reperfusion (I/R) injury, during which excess reactive oxygen species (ROS) are produced. ROS subsequently damage renal cells, leading to the development of AKI. Here, we investigated whether renal I/R injury could be attenuated by the antioxidant EPC-K1. METHODS: We divided male Wistar rats into the following three groups: (1) a renal I/R group, (2) an EPC-K1 + renal I/R group and (3) a control group. Rats were sacrificed 24 h after treatment (I/R or sham). To measure oxidative stress in renal tissue, histological examinations were performed and serum levels of blood urea nitrogen (BUN) and creatinine were measured. The antioxidant action of EPC-K1 was also evaluated in RAW264.7 cells stimulated with antimycin A. RESULTS: Serum BUN and creatinine levels were elevated in the I/R group; however, this increase was significantly attenuated by EPC-K1 in the EPC-K1 + I/R group. Renal tissue injury was also significantly lower in the EPC-K1 + I/R group compared with the I/R group. In vitro experiments showed that EPC-K1 significantly attenuated the generation of ROS induced by antimycin A. CONCLUSION: In our study, EPC-K1 was able to attenuate AKI due to renal I/R by reducing oxidative stress. These results suggest that EPC-K1 may be effective against various types of I/R injury.

Relationship between HMGB1 and tissue protective effects of HSP72 in a LPS-induced systemic inflammation model.

BACKGROUND: Heat shock protein 72 (HSP72(a)) exhibits cell- and organ-protective effects in response to inflammation. Moreover, high mobility group box 1 (HMGB1) protein is a lethal mediator of acute inflammation. We examined associations between HMGB1 expression and protective effects observed when whole-body hyperthermia (WH) induces HSP72 in a lipopolysaccharide (LPS(b))-induced inflammation model. MATERIALS AND METHODS: Serum cytokine and HMGB1 levels, as well as HSP72 and HMGB1 expression in lung tissue were analyzed after WH treatment. Furthermore, effects of prior induction of HSP72 and silencing of HSP72 on HMGB1 secretion were examined in cultured RAW264.7 cells. RESULTS: Survival improved significantly from 33% in the LPS group to 78% in the WH+LPS group. Interleukin-6, tumor necrosis factor-α, and HMGB1 concentrations were significantly lower in WH-treated rats. Furthermore, inflammation was reduced in lungs of WH-treated rats. Prior induction of HSP72 resulted in significantly decreased HMGB1 secretion by RAW264.7 cells in vitro, while silencing of HSP72 prevented this decrease. CONCLUSIONS: Our results suggest that HSP72 induction by thermal pretreatment reduced inflammation and improved survival in the LPS-induced systemic inflammation model. These effects, which were associated with inhibition of HMGB1 expression, potentially involve HSP-mediated inhibition of HMGB1 secretion.

Gabexate mesilate inhibits the expression of HMGB1 in lipopolysaccharide-induced acute lung injury.

High mobility group box 1 (HMGB1) is an important late mediator of acute lung injury. Gabexate mesilate (GM) is a synthetic protease inhibitor with some anti-inflammatory action. We aimed to evaluate the effect of GM on HMGB1 in lipopolysaccharide (LPS)-induced lung injury in rats. Prior to the injection of LPS to induce lung injury, rats were administered saline or GM. Injury to the lung and expression of HMGB1, plasminogen activator inhibitor-1 (PAI-1), and protease-activated receptor-2 (PAR-2) were examined. In an accompanying in vitro study, we performed LPS stimulation under GM administration in a mouse macrophage cell line and measured the quantity of HMGB1 and cytokines in the supernatant, and cell signal in the cells. Histologic examination revealed that interstitial edema, leukocytic infiltration, and HMGB1 protein expression were markedly reduced in the GM+LPS group compared wih the LPS group. Furthermore, LPS-induced increases in PAI-1 and PAR-2 activity and in plasma HMGB1 concentrations were lower in the rats given both GM and LPS than in the rats given LPS alone. Release of HMGB1 and cytokines from the cell after the administration of LPS were decreased by GM. Phosphorylation of IκB was inhibited by GM. GM may have inhibited PAI-1 and PAR-2, thereby indirectly inhibiting HMGB1 and reducing tissue damage in the lung. This indicates that GM can inhibit lung injury induced by LPS in rats. GM is a candidate for use in novel strategies to prevent or minimize lung injury in sepsis.