Lisa Rancan

Melatonin can improve insulin resistance and aging-induced pancreas alterations in senescence-accelerated prone male mice (SAMP8).

The aim of the present study was to investigate the effect of aging on several parameters related to glucose homeostasis and insulin resistance in pancreas and how melatonin administration could affect these parameters. Pancreas samples were obtained from two types of male mice models: senescence-accelerated prone (SAMP8) and senescence-accelerated-resistant mice (SAMR1). Insulin levels in plasma were increased with aging in both SAMP8 and SAMR1 mice, whereas insulin content in pancreas was decreased with aging in SAMP8 and increased in SAMR1 mice. Expressions of glucagon and GLUT2 messenger RNAs (mRNAs) were increased with aging in SAMP8 mice, and no differences were observed in somatostatin and insulin mRNA expressions. Furthermore, aging decreased also the expressions of Pdx-1, FoxO 1, FoxO 3A and Sirt1 in pancreatic SAMP8 samples. Pdx-1 was decreased in SAMR1 mice, but no differences were observed in the rest of parameters on these mice strains. Treatment with melatonin was able to decrease plasma insulin levels and to increase its pancreatic content in SAMP8 mice. In SAMR1, insulin pancreatic content and plasma levels were decreased. HOMA-IR was decreased with melatonin treatment in both strains of animals. On the other hand, in SAMP8 mice, treatment decreased the expression of glucagon, GLUT2, somatostatin and insulin mRNA. Furthermore, it was also able to increase the expression of Sirt1, Pdx-1 and FoxO 3A. According to these results, aging is associated with significant alterations in the relative expression of pancreatic genes associated to glucose metabolism. This has been especially observed in SAMP8 mice. Melatonin administration was able to improve pancreatic function in old SAMP8 mice and to reduce HOMA-IR improving their insulin physiology and glucose metabolism.

Melatonin Counteracts at a Transcriptional Level the Inflammatory and Apoptotic Response Secondary to Ischemic Brain Injury Induced by Middle Cerebral Artery Blockade in Aging Rats.

Abstract Aging increases oxidative stress and inflammation. Melatonin counteracts inflammation and apoptosis. This study investigated the possible protective effect of melatonin on the inflammatory and apoptotic response secondary to ischemia induced by blockade of the right middle cerebral artery (MCA) in aging male Wistar rats. Animals were subjected to MCA obstruction. After 24 h or 7 days of procedure, 14-month-old nontreated and treated rats with a daily dose of 10 mg/kg melatonin were sacrificed and right and left hippocampus and cortex were collected. Rats aged 2 and 6 months, respectively, were subjected to the same brain injury protocol, but they were not treated with melatonin. mRNA expression of interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), Bcl-2-associated death promoter (BAD), Bcl-2-associated X protein (BAX), glial fibrillary acidic protein (GFAP), B-cell lymphoma 2 (Bcl-2), and sirtuin 1 was measured by reverse transcription–polymerase chain reaction. In nontreated animals, a significant time-dependent increase in IL-1β, TNF-α, BAD, and BAX was observed in the ischemic area of both hippocampus and cortex, and to a lesser extent in the contralateral hemisphere. Hippocampal GFAP was also significantly elevated, while Bcl-2 and sirtuin 1 decreased significantly in response to ischemia. Aging aggravated these changes. Melatonin administration was able to reverse significantly these alterations. In conclusion, melatonin may ameliorate the age-dependent inflammatory and apoptotic response secondary to ischemic cerebral injury.

Melatonin decreases the expression of inflammation and apoptosis markers in the lung of a senescence-accelerated mice model

Aging is associated with an increase in oxidative stress and inflammation. The aging lung is particularly affected since it is continuously exposed to environmental oxidants while antioxidant machinery weakens with age. Melatonin, a free radical scavenger, counteracts inflammation and apoptosis in healthy cells from several tissues. Its effects on the aging lung are, however, not yet fully understood. This study aimed to investigate the effect of chronic administration of melatonin on the expression of inflammation markers (TNF-α, IL-1β, NFκB2, HO-1) and apoptosis parameters (BAD, BAX, AIF) in the lung tissue of male senescence-accelerated prone mice (SAMP8). In addition, RNA oxidative damage, as the formation of 8-hydroxyguanosine (8-OHG), was also evaluated. Young and old animals, aged 2 and 10 months respectively, were divided into 4 groups: untreated young, untreated old, old mice treated with 1mg/kg/day melatonin, and old animals treated with 10mg/kg/day melatonin. Untreated young and old male senescence accelerated resistant mice (SAMR1) were used as controls. After 30 days of treatment, animals were sacrificed. Lungs were collected and immediately frozen in liquid nitrogen. mRNA and protein expressions were measured by RT-PCR and Western blotting, respectively. Levels of 8-OHG were quantified by ELISA. Mean values were analyzed using ANOVA. Old nontreated SAMP8 animals showed increased (p<0.05) mRNA and protein levels of TNF-α, IL-1β, NFκB2, and HO-1 compared to young mice and SAMR1 mice. Melatonin treatment with either dose reversed the aging-derived inflammation (p<0.05). BAD, BAX and AIF expressions also rose with aging, the effect being counteracted with melatonin (p<0.05). Aging also caused a significant elevation (p<0.05) in SAMP8 8-OHG values. This increase was not observed in animals treated with melatonin (p<0.05). In conclusion, melatonin treatment was able to modulate the inflammatory and apoptosis status of the aging lungs, exerting a protective effect on age-induced damage.

Intravenous lidocaine decreases tumor necrosis factor alpha expression both locally and systemically in pigs undergoing lung resection surgery.

BACKGROUND:Lung resection surgery is associated with an inflammatory reaction. The use of 1-lung ventilation (OLV) seems to increase the likelihood of this reaction. Different prophylactic and therapeutic measures have been investigated to prevent lung injury secondary to OLV. Lidocaine, a commonly used local anesthetic drug, has antiinflammatory activity. Our main goal in this study was to investigate the effect of IV lidocaine on tumor necrosis factor &agr; (TNF-&agr;) lung expression during lung resection surgery with OLV. METHODS:Eighteen pigs underwent left caudal lobectomy. The animals were divided into 3 groups: control, lidocaine, and sham. All animals received general anesthesia. In addition, animals in the lidocaine group received a continuous IV infusion of lidocaine during surgery (1.5 mg/kg/h). Animals in the sham group only underwent thoracotomy. Samples of bronchoalveolar lavage (BAL) fluid and plasma were collected before initiation of OLV, at the end of OLV, at the end of surgery, and 24 hours after surgery. Lung biopsy specimens were collected from the left caudal lobe (baseline) before surgery and from the mediastinal lobe and the left cranial lobe 24 hours after surgery. Samples were flash-frozen and stored to measure levels of the following inflammatory markers: interleukin (IL) 1&bgr;, IL-2, IL-10, TNF-&agr;, nuclear factor &kgr;B, monocyte chemoattractant protein-1, inducible nitric oxide synthase, and endothelial nitric oxide synthase. Markers of apoptosis (caspase 3, caspase 9, Bad, Bax, and Bcl-2) were also measured. In addition, levels of metalloproteinases and nitric oxide metabolites were determined in BAL fluid and in plasma samples. A nonparametric test was used to examine statistical significance. RESULTS:OLV caused lung damage with increased TNF-&agr; expression in BAL, plasma, and lung samples. Other inflammatory (IL-1&bgr;, nuclear factor &kgr;B, monocyte chemoattractant protein-1) and apoptosis (caspase 3, caspase 9, and BAX) markers were also increased. With the use of IV lidocaine there was a significant decrease in the levels of TNF-&agr; in the same samples compared with the control group. Lidocaine administration also reduced the inflammatory and apoptotic changes observed in the control group. Hemodynamic values, blood gas values, and airway pressure were similar in all groups. CONCLUSIONS:Our results suggest that lidocaine can prevent OLV-induced lung injury through reduced expression of proinflammatory cytokines and lung apoptosis. Administration of lidocaine may help to prevent lung injury during lung surgery with OLV.

Assessment of circulating concentrations of proinflammatory and anti-inflammatory cytokines and nitric oxide in dogs with brachycephalic airway obstruction syndrome

OBJECTIVE To evaluate plasma concentrations of inflammatory mediators in dogs with brachycephalic airway obstruction syndrome, identify a possible role for these mediators in the syndrome, and investigate the relationship between plasma concentrations of inflammatory mediators and severity of clinical signs. ANIMALS 17 dogs with brachycephalic airway obstruction syndrome and 10 mesocephalic (control) dogs. PROCEDURES A blood sample was collected once from each dog. Plasma concentrations of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6, IL-17A, IL-10, and IL-13 were measured with ELISAs. Nitric oxide (NO) concentrations were determined with a Griess test. For analysis, brachycephalic dogs were categorized into groups depending on weight (small [< 16 kg]) and large [≥ 16 kg]) or on whether they required medical or surgical treatment. RESULTS Compared with control dog values, plasma concentrations of TNF-α, IL-10, IL-13, and IL-17A were significantly higher in brachycephalic dogs and markedly so for brachycephalic dogs that required surgery; findings for small and large brachycephalic dogs did not differ. A similar pattern of differences between control and brachycephalic dogs was identified for plasma NO concentration. Plasma IL-1β and IL-6 concentrations in control and brachycephalic dogs did not differ. CONCLUSIONS AND CLINICAL RELEVANCE In brachycephalic dogs, plasma TNF-α, IL-10, IL-13, L-17A, and NO concentrations were higher than values in control dogs and appeared to be associated with disease severity. These variables may be useful as indicators of inflammatory processes associated with brachycephalic airway obstruction syndrome in dogs.

Sevoflurane prevents liver inflammatory response induced by lung ischemia-reperfusion.

Background Transplants cause ischemia-reperfusion (IR) injury that can affect distant organs. Liver is particularly sensitive to IR injury. The present randomized experimental study was designed to investigate a possible protective effect of sevoflurane against liver inflammatory response to lung IR in a lung upper lobe left autotransplant model. Methods Two groups (sevoflurane and control) of eight swines each were submitted to upper lobe left lung autotransplant. Hypnotic maintenance was performed with sevoflurane 3% or propofol 8 to 10 mg/kg per hr until pneumonectomy was done; then propofol was used for all animals. Blood and liver samples were taken in four different moments: prepneumonectomy, prereperfusion, 10 min postreperfusion and 30 min postreperfusion to measure levels of interleukin (IL)-1&bgr;, IL-10, tumor necrosis factor (TNF)-&agr;, monocyte chemotactic protein (MCP)-1, nuclear factor (NF)-&kgr;B, C-reactive protein, ferritin and caspase 3. Non-parametric test was used to find statistical meaning. Results Lung IR markedly increased the expression of TNF-&agr;, IL-1&bgr;, MCP-1, NF-&kgr;B and caspase activity in control livers compared with basal levels, whereas liver IL-10 expression decreased 10 and 30 min post-reperfusion. Sevoflurane significantly decreased TNF-&agr;, IL-1&bgr;, MCP-1, NF-&kgr;B liver expression and caspase 3 activity. Sevoflurane also reverted the lung IR-induced decrease in IL-10 expression. Conclusions The present results indicate that lung IR caused hepatic injury. Sevoflurane attenuated liver injury in a model of upper lobe left lung autotransplant in pigs.

Ischaemic preconditioning prevents the liver inflammatory response to lung ischaemia/reperfusion in a swine lung autotransplant model †

OBJECTIVES Lung ischaemia/reperfusion (IR) induces a systemic inflammatory response that causes damage to remote organs. The liver is particularly sensitive to circulating inflammatory mediators that occur after IR of remote organs. Recently, remote ischaemic preconditioning has been proposed as a surgical tool to protect several organs from IR. The present study was designed to investigate a possible protective effect of lung ischaemic preconditioning (IP) against the liver inflammatory response to lung IR. METHODS Two groups [IP and control (CON)] of 10 Large White pigs underwent lung autotransplants (left pneumonectomy, ex situ cranial lobectomy and caudal lobe reimplantation). Before pneumonectomy was performed in the study group, IP was induced with two 5-min cycles of left pulmonary arterial occlusion and a 5-min interval of reperfusion between the two occlusions. Five animals underwent sham surgery. Liver biopsies were obtained during surgery at (i) prepneumonectomy, (ii) prereperfusion, (iii) 10 min after reperfusion of the implanted lobe and (iv) 30 min after reperfusion. The expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-1, IL-10 and inducible form of nitric oxide synthase (iNOS) was analysed by western blotting. The expression of mRNA for TNF-α, IL1, IL-10, monocyte chemoattractant protein-1 (MCP-1), nuclear factor kappa beta and iNOS was analysed by reverse transcription-polymerase chain reaction. Caspase-3 activity was determined by enzyme-linked immunosorbent assay. Non-parametric tests were used to compare differences between and within groups. RESULTS Lung IR markedly increased expression of TNF-α (P = 0.0051) and IL-1 (P = 0.0051) and caspase-3 activity (P = 0.0043) in the CON group compared with the prepneumonectomy levels. A decrease of IL-10 mRNA expression was observed in the CON group after lung reperfusion. In the IP group, TNF-α (P = 0.0011) and IL-1 (P = 0.0001) expression and caspase-3 activity (P < 0.0009) were lower after reperfusion than in the CON group. IP caused reversion of the observed decrease of IL-10 mRNA expression (P = 0.016) induced in liver tissue by lung IR. Lung IR markedly increased the expression of mRNA MCP-1 after 10 min (P = 0.0051) and 30 min (P = 0.0051) of reperfusion. These increases were not observed in the IP or sham groups. CONCLUSIONS IP prevented liver injury induced by lung IR through the reduction of proinflammatory cytokines and hepatocyte apoptosis.

Protective effect of resveratrol against inflammation, oxidative stress and apoptosis in pancreas of aged SAMP8 mice

Abstract Aging is a physiological state in which a progressive decline in organ functions is accompanied by the development of age‐related diseases. Resveratrol supplementation has been shown to exert anti‐inflammatory and antioxidant effects in various mammalian models of aging. Senescence‐accelerated mice (SAM) are commonly used as animal models to investigate the aging process. In the present study, the effects of inflammation, oxidative stress and apoptosis in pancreas of two different types of SAM (SAMR1 or resistant to aging, and SAMP8 or prone to aging) have been analysed, as well as the effect of resveratrol administration (5 mg/kg/day) on these parameters in the SAMP8 strain. mRNA expressions of sirtuin 1 and FoxO factors were found to be decreased with aging in SAMP8 mice. An increase in inflammatory status and nuclear‐factor kappa B (NF&kgr;B) protein expression was also observed in old mice, together with a decrease of anti‐apoptotic markers and antioxidant‐enzyme activity. Resveratrol administration was able to increase sirtuin 1 mRNA expression, as well as decreasing NF&kgr;B expression and reducing the proinflammatory and prooxidant status associated with age. In conclusion, resveratrol was able to modulate the inflammatory, oxidative and apoptotic status related to aging, thereby exerting a protective effect on pancreas age‐induced damage. HighlightsAging increases the proinflammatory, pro‐oxidant and pro‐apoptotic status in pancreas.Resveratrol reduces inflammatory and apoptotic marker levels in aged pancreas.Resveratrol exerts a protective effect against pancreatic damage related to aging.

Oxidative stress in follicular fluid of young women with low response compared with fertile oocyte donors.

The aim of this study was to determine the concentrations of oxidative stress markers, antioxidant enzymes and cytokines in the follicular fluid of young women with low response in ovarian stimulation cycles compared with high responders and fertile oocyte donors of the same age, to assess the impact of oxidative stress on ovarian reserve. The activity of follicular fluid antioxidant enzymes glutathione transferase, glutathione reductase and glutathione peroxidase was significantly lower in young women with reduced ovarian reserve compared with that in high responders and oocyte donors. Follicular fluid concentrations of oxidative stress marker malondialdehyde combined with 4-hydroxyalkenals and nitric oxide were higher in low responders than in high responders and oocyte donors. Significant differences between low responders and donors in concentrations of IL-2, IL-6, IL-8 and vascular endothelial growth factor were observed, with higher concentrations in low responders. However, IL-10 concentration was lower in low responders than in high responders and donors. No significant differences were found in follicular fluid concentrations of tumour necrosis factor alpha between the three groups. These results demonstrate that different concentrations of oxidative stress markers, oxidant enzymes and cytokines in low responders compared with high responders and oocyte donors may negatively impact ovarian response.

Protective effect of xanthohumol against age-related brain damage

It has been recently shown that xanthohumol, a flavonoid present in hops, possesses antioxidant, anti-inflammatory and chemopreventive properties. However, its role in the aging brain has not been addressed so far. Therefore, this study aimed to investigate the possible neuroprotective activity of xanthohumol against age-related inflammatory and apoptotic brain damage in male senescence-accelerated prone mice (SAMP8). Animals were divided into 4 groups: Untreated young mice, untreated old mice and old mice treated either with 1 mg kg-1 day-1 or 5 mg kg-1 day-1 xanthohumol. Young and old senescence accelerated resistant mice (SAMR1) were used as controls. After 30 days of treatment, animals were sacrificed and their brains were collected and immediately frozen in liquid nitrogen. mRNA (GFAP, TNF-α, IL-1β, AIF, BAD, BAX, XIAP, NAIP and Bcl-2) and protein (GFAP, TNF-α, IL-1β, AIF, BAD, BAX, BDNF, synaptophysin and synapsin) expressions were measured by RT-PCR and Western blotting, respectively. Significant increased levels of pro-inflammatory (TNF-α, IL-1β) and pro-apoptotic (AIF, BAD, BAX) markers were observed in both SAMP8 and SAMR1 old mice compared to young animals (P<.05) and also in SAMP8 untreated old mice compared to SAMR1 (P<.05). These alterations were significantly less evident in animals treated with both doses of xanthohumol (P<.05). Also, a reduced expression of synaptic markers was observed in old mice compared to young ones (P<.05) but it significantly recovered with 5 mg kg-1 day-1 xanthohumol treatment (P<.05). In conclusion, xanthohumol treatment modulated the inflammation and apoptosis of aged brains, exerting a protective effect on damage induced by aging.