Differential expression of hepatocyte growth factor in liver, kidney, lung, and spleen following burn in rats

Naringenin improves the healing process of thermally-induced skin damage in rats

Objective

To evaluate the effect of the phenolic compound naringenin on thermal burn-induced inflammatory responses and oxidative stress in rats.

Methods

First degree thermal burn injuries were induced in shaved rats by 10 s immersion of the back surface in water at 90℃. Naringenin treatment (25, 50 and 100 mg/kg/day) was initiated 24 h following burn injury, and continued for 7 days. On treatment day 7, serum tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, nitric oxide (NO), prostaglandin (PG)E₂, caspase-3, leukotriene (LT)-B4 and nuclear factor (NF)-κB levels were quantified. Skin sample glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) levels, and catalase, superoxide dismutase (SOD), glutathione-S-transferase (GST) and glutathione peroxidase (GPx) activities, were also measured.

Results

Serum inflammatory biomarkers were significantly increased in thermal-burn injured rats versus uninjured controls. Naringenin significantly inhibited the increased proinflammatory markers at day 7 of treatment. Increased TBARS levels and decreased GSH levels in wounded skin were significantly restored by naringenin treatment at day 7. SOD, catalase, GPx and GST activities were markedly inhibited in wounded skin tissues, and were significantly increased in naringenin-treated rats.

Conclusion

Naringenin treatment showed anti-inflammatory and antioxidant effects in rats with thermal burn-induced injury.

Caffeic acid phenethyl ester as a protective agent against nephrotoxicity and/or oxidative kidney damage: a detailed systematic review

Caffeic acid phenethyl ester (CAPE), an active component of propolis, has been attracting the attention of different medical and pharmaceutical disciplines in recent years because of its antioxidant, anti-inflammatory, antiproliferative, cytotoxic, antiviral, antifungal, and antineoplastic properties. One of the most studied organs for the effects of CAPE is the kidney, particularly in the capacity of this ester to decrease the nephrotoxicity induced by several drugs and the oxidative injury after ischemia/reperfusion (I/R). In this review, we summarized and critically evaluated the current knowledge regarding the protective effect of CAPE in nephrotoxicity induced by several special medicines such as cisplatin, doxorubicin, cyclosporine, gentamycin, methotrexate, and other causes leading to oxidative renal injury, namely, I/R models and senility.

Skeletal muscle satellite cell activation following cutaneous burn in rats

BACKGROUND

Cutaneous burn distant from skeletal muscles induces atrophy; however, its effect on muscle stem cells resident in skeletal muscle (satellite cells) distal to burn is not known.

METHODS

Satellite cell activation was measured in predominantly fast-twitch [tibialis anterior, extensor digitorum longus (EDL), plantaris, and gastrocnemius] and slow-twitch (soleus) muscles of rats that received either 40% total body surface area full-thickness scald burn or sham burn to the trunk area by determining bromodeoxyuridine incorporation, MyoD, and Pax7 immunohistochemistry in vivo ≤48 h after burn. To determine the effects of circulating factors on satellite cell activation, satellite cell cultures were treated with serum from sham or burn rats.

RESULTS

In vivo activation of satellite cells was increased in fast muscles isolated from burn as compared to sham animals, whereas a significant response was not seen in slow muscles. Serum taken from animals in the burn group increased the activation of satellite cells isolated from both sham and burn animals in vitro, suggesting that circulating factors have the potential to increase satellite cell activation following burn.

CONCLUSIONS

Increases in satellite cell activation in muscles distal to burn are fiber-type-dependent, and circulating factors may play a role in the activation of satellite cells following burn. A better understanding of the impact of burn on satellite cell functionality will allow us to identify the cellular mechanisms of long-term muscle atrophy.

The hepatic response to thermal injury: is the liver important for postburn outcomes?

Thermal injury produces a profound hypermetabolic and hypercatabolic stress response characterized by increased endogenous glucose production via gluconeogenesis and glycogenolysis, lipolysis, and proteolysis. The liver is the central body organ involved in these metabolic responses. It is suggested that the liver, with its metabolic, inflammatory, immune, and acute phase functions, plays a pivotal role in patient survival and recovery by modulating multiple pathways following thermal injury. Studies have evaluated the role and function of the liver during the postburn response and showed that liver integrity and function are essential for survival, and that hepatic acute phase proteins are strong predictors for postburn survival. This review discusses these studies and delineates the pivotal role of the liver in patients following severe thermal injury.

Decreased Growth Rate of Lung Metastatic Lesions after Splenectomy in Mice

BACKGROUND

The effect of splenectomy on hematogenous metastases of malignant tumors remains controversial. The aim of this study was to clarify the effect of splenectomy on hematogenous metastases in an animal model.

METHODS

Colon 26 cancer cells were inoculated into the lateral tail vein of 90 mice. The mice were then assigned to a splenectomy group or a control group. Lung weight, number of lung metastases, size of metastatic nodules, and serum vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) levels after the surgical procedure were measured and compared between the two groups.

RESULTS

The lung nodules were significantly smaller in the splenectomy group than in the control group. In both groups, the serum VEGF levels increased on day 1 and then decreased. The serum VEGF levels on day 5 were significantly lower in the splenectomy group than in the control group. The serum bFGF levels were significantly lower in the splenectomy group than in the control group on days 1 and 5. Immunohistochemical study showed that bFGF was produced by reticuloendothelial cells of the spleen.

CONCLUSION

The growth rate of hematogenous metastatic lesions appears to decrease after splenectomy and may be associated with decreases in serum levels of VEGF and bFGF induced by splenectomy.

Melatonin reduces oxidative damage to skin and normalizes blood coagulation in a rat model of thermal injury

This study was designed to determine the effect of melatonin treatment on the glutathione (GSH) and lipid peroxidation (LPO) levels in the skin as well as prothrombin time (PT) and fibrin degradation products (FDPs) in the blood of rats with thermal injury. Under ether anaesthesia, the shaved dorsum of the rats was exposed to 90 degrees C bath for 10 s to induce burn injury. Rats were decapitated either 3 or 24 hours after burn injury. Melatonin (10 mg/kg) was administered i.p. immediately after burn injury to same animals. In the 24 hour burn group, melatonin injections were repeated for two more occasions 8 and 16 h after burn injury. In the control group the same protocol was applied except that the dorsum was exposed to a 25 degrees C water bath for 10 s. Severe skin scald injury (30% of total body surface area) caused a significant decrease in PT at post burn 3 and 24 hours. FDPs was not increased at post burn 3 hour but was significantly increased at post burn 24 hour. GSH levels were significantly depressed at post burn 3 hour but were not changed at post burn 24 hour. LPO levels were significantly increased both at post burn 3 and 24 hours. Skin protein levels were significantly reduced at post burn 24 hour as evidenced by electrophoresis. Treatment of rats with melatonin normalized PT levels both at post burn 3 and 24 hours. FDP decreased at post burn 24 hour due to melatonin treatment. GSH levels significantly increased as a result of melatonin treatment both at post burn 3 and 24 hours melatonin treatment. LPO levels were not changed by melatonin at post burn 3 hour; however, the melatonin significantly decreased LPO values at post burn 24 hours. In conclusion, exogenously administered melatonin reduced skin oxidant damage and normalized the activated blood coagulation induced by thermal trauma.

Protective effect of aqueous garlic extract against oxidative organ damage in a rat model of thermal injury

Oxygen free radicals have been implicated in mediating various pathological processes including burn-induced organ damage. This study was designed to determine the possible protective effect of aqueous garlic extract against oxidative organ damage distant from the original burn wound. Under ether anaesthesia, rats were subjected to severe skin scald injury covering 30% of total body surface area. Rats were decapitated either 2 h or 24 h after burn injury. Aqueous garlic extract (1 ml/kg) was administered i.p. immediately after burn injury. In the 24-h burn group injection was repeated once more (at 12 hour) following the burn injury. Liver, intestine and lung tissues were taken for the determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and protein oxidation (PO). Burn injury caused a significant decrease in GSH level, and significant increases in MDA and PO levels, and MPO activity at post-burn 2 and 24 hours. Since garlic extract reversed these oxidant responses it seems likely that garlic extract protects tissues against oxidative damage.

Melatonin improves oxidative organ damage in a rat model of thermal injury

Animal models of burn injury indicate oxygen radicals as causative agents in the local wound response, as well as in the development of burn shock and distant organ injury. This study was designed to determine the possible protective effect of melatonin treatment against oxidative damage in the liver, lung and intestine induced by burn injury. Under ether anaesthesia, the shaved dorsum of rats was exposed to a 90 degrees C bath for 10s to induce burn injury. Rats were decapitated either 3 or 24h after burn injury. Melatonin was administered i.p. immediately after burn injury. In the 24h burn group, melatonin injections were repeated for two more occasions. In the sham group the same protocol was applied except that the dorsum was dipped in a 25 degrees C water bath for 10s. Liver, lung and intestine tissues were taken for the determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and protein oxidation (PO). Severe skin scald injury (30% of total body surface area) caused a significant decrease in GSH level, significant increases in MDA and PO levels, and MPO activity at postburn 3 and 24h. Treatment of rats with melatonin (10mg/kg) significantly elevated the reduced GSH levels while it decreased MDA and PO levels as well as MPO activity.

Hepatocyte growth factor and the kidney

Hepatocyte growth factor (HGF) and its specific c-met receptor constitute a paired signaling system that plays an important role in renal development and in the maintenance of normal adult kidney structure and functions. HGF elicits potent mitogenic, motogenic, morphogenic, and antiapoptotic activities in renal tubular epithelial cells. The nature of these pleiotropic actions renders it to be specifically suited to preserve and to reconstitute the structural and functional integrity of renal tubules after acute renal injury. Emerging evidence also indicates that both endogenous and exogenous HGF are beneficial by inhibiting the onset and progression of chronic renal diseases in various animal models. Administration of exogenous HGF protein, or its gene, effectively inhibits the activation of matrix-producing myofibroblasts, attenuates extracellular matrix deposition and interstitial fibrosis, and suppresses profibrogenic cytokine transforming growth factor-beta1 and its type I receptor expression in vivo. Hence, although more studies are warranted to further clarify its role in various chronic renal fibrosis models, delivery of either HGF or its gene may hold promise as a novel therapeutic strategy for promoting initial protection and subsequently regenerative repair after acute insult, and for ameliorating renal fibrosis and kidney dysfunction in chronically diseased conditions.