Search

Hospital-acquired anemia is defined as a new-onset anemia in hospitalized patients who have a normal hemoglobin level at admission. Its prevalence is unknown and most studies published on this topic have been conducted in intensive care unit patients with limited applicability to less acute settings, such as internal medicine wards. We conducted a retrospective study and enrolled 129 patients who were admitted to an Internal Medicine Unit between October 2021 and February 2022. The median value of phlebotomy during hospitalization was 46 ml (IQR 30–72 ml), whereas the median length of hospital stay was 9 days (IQR 5–13 days). The median value of hemoglobin reduction was −0.63 g/dl (p 85 ml had a hemoglobin reduction > 0.6 g/dl. 20.9% of patients developed anemia during the hospital stay (7% moderate and 13.9% mild). No cases of severe anemia were observed. The volume of blood drawn during the hospital stay and the Hb value on admission were the only two variables statistically associated with the development of anemia, whereas gender, age, and chronic diseases, such as diabetes, history of cancer, or heart failure, were not. Strategies, such as elimination of unnecessary laboratory tests and the use of smaller tubes for blood collection, are needed to reduce the volume of iatrogenic blood loss and avoid blood wastage occurring during hospitalization in internal medicine patients.

In the present study, we used a mouse model of Alzheimer’s disease (AD) (3×Tg-AD mice) to longitudinally analyse the expression level of PDIA3, a protein disulfide isomerase and endoplasmic reticulum (ER) chaperone, in selected brain limbic areas strongly affected by AD-pathology (amygdala, entorhinal cortex, dorsal and ventral hippocampus). Our results suggest that, while in Non-Tg mice PDIA3 levels gradually reduce with aging in all brain regions analyzed, 3×Tg-AD mice showed an age-dependent increase in PDIA3 levels in the amygdala, entorhinal cortex, and ventral hippocampus. A significant reduction of PDIA3 was observed in 3×Tg-AD mice already at 6 months of age, as compared to age-matched Non-Tg mice. A comparative immunohistochemistry analysis performed on 3×Tg-AD mice at 6 (mild AD-like pathology) and 18 (severe AD-like pathology) months of age showed a direct correlation between the cellular level of Aβ and PDIA3 proteins in all the brain regions analysed, even if with different magnitudes. Additionally, an immunohistochemistry analysis showed the presence of PDIA3 in all post-mitotic neurons and astrocytes. Overall, altered PDIA3 levels appear to be age- and/or pathology-dependent, corroborating the ER chaperone’s involvement in AD pathology, and supporting the PDIA3 protein as a potential novel therapeutic target for the treatment of AD.

Emphysematous Cystitis (EC) is a rare form of complicated urinary tract infection, characterized by the presence of gas in the bladder and in its wall. Diabetes Mellitus (DM) is the major risk factor. Clinical manifestations in EC can range from asymptomatic form to severe sepsis and fatal events. Abdominal imaging is requested to diagnose EC and evaluate its severity. Early diagnosis and appropriate management improve the outcome. We report a case of incidental EC diagnosis in an 82-yearold diabetic male who was investigated for severe anemia.

Introduction: Several studies have demonstrated a positive correlation between severe hepatic steatosis and metabolic alterations; however, few studies have addressed the potential association between different grades of steatosis and clinical patterns in a non-diabetic population. Methods: We conducted a cross-sectional study of 223 non-diabetic individuals. The severity of steatosis was assessed using B-mode ultrasound. We analyzed lipid and glucose profiles according to the severity of hepatic steatosis. Estimated glomerular filtration rate (eGFR) values were also recorded to investigate the potential impact of steatosis on kidney function. Results: Patients with steatosis were found to have higher insulinemia and mean values of fasting plasma glucose compared to patients without steatosis. A significant decrease in high-density lipoprotein level was observed only in patients with severe or moderate steatosis. All grades of steatosis were associated with increased triglyceride levels, which were more significant in severe steatosis. Subgroup analysis by body mass index demonstrated a significant difference between lean patients with steatosis and lean patients without steatosis for triglycerides (p = 0.002) and high-density lipoprotein levels (p = 0.019). Finally, patients diagnosed with steatosis demonstrated a higher prevalence of estimated glomerular filtration rate Conclusion: The degree of steatosis diagnosed at ultrasound may predict glucose or lipid metabolism disorders and a decline in kidney function in a non-diabetic population.

Although direct-acting antivirals are very effective and safe drugs, several authors have reported the alteration of lipid profile during and after anti-HCV therapy suggesting a potential impact on the risk of cardiovascular events. We performed a systematic review and meta-analysis of observational studies to investigate the magnitude and temporal trend of lipid profile changes in DAA treated patients. All selected studies included data on lipid profile before starting therapy and at least one follow-up assessment during or after antiviral treatment. We identified 14 studies (N = 1537 patients) after removing duplicates. Pooled data showed an increase in total cholesterol 4 weeks after starting therapy (+ 15.86 mg/dl; 95% CI + 9.68 to 22.05; p

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of liver disease globally, and represents a health care burden as treatment options are very scarce. The reason behind the NAFLD progression to non-alcoholic steatohepatitis (NASH) is not completely understood. Recently, the deficiency of micronutrients (e.g., vitamins, minerals, and other elements) has been suggested as crucial in NAFLD progression, such that recent studies reported the potential hepatic antioxidant properties of micronutrients supplementation. However, very little is known. Here we have explored the potential beneficial effects of dietary supplementation with FLINAX, a novel mixture of nutraceuticals (i.e., vitamin E, vitamin D3, olive dry-extract, cinnamon dry-extract and fish oil) in a NAFLD model characterized by oxidative stress and mitochondrial function impairment. Steatosis was firstly induced in Wistar rats by feeding with a high-fat/high-cholesterol diet for 4 weeks, and following this the rats were divided into two groups. One group (n = 8) was treated for 2 weeks with a normal chow-diet, while a second group (n = 8) was fed with a chow-diet supplemented with 2% FLINAX. Along with the entire experiment (6 weeks), a third group of rats was fed with a chow-diet only as control. Statistical analysis was performed with Student’s T test or one-way ANOVA followed by post-hoc Bonferroni test when appropriate. Steatosis, oxidative stress and mitochondrial respiratory chain (RC) complexes activity were analyzed in liver tissues. The dietary supplementation with FLINAX significantly improved hepatic steatosis and lipid accumulation compared to untreated rats. The mRNA and protein levels analysis showed that CPT1A and CPT2 were up-regulated by FLINAX, suggesting the enhancement of fatty acids oxidation (FAO). Important lipoperoxidation markers (i.e., HNE- and MDA-protein adducts) and the quantity of total mitochondrial oxidized proteins were significantly lower in FLINAX-treated rats. Intriguingly, FLINAX restored the mitochondrial function, stimulating the activity of mitochondrial RC complexes (i.e., I, II, III and ATP-synthase) and counteracting the peroxide production from pyruvate/malate (complex I) and succinate (complex II). Therefore, the supplementation with FLINAX reprogrammed the cellular energy homeostasis by restoring the efficiency of mitochondrial function, with a consequent improvement in steatosis.

BACKGROUND Transcatheter Arterial chemoembolization (TACE) is the first-line option for the intermediate-stage hepatocellular carcinoma. Guidelines do not define the number of TACE sessions to be repeated before stopping treatment and switching to sorafenib. METHODS We retrospectively analysed 76 patients aged ≥65 years who were treated by multiple TACE sessions (re-TACE group; N = 36 patients) or one TACE session followed by sorafenib (TACE/Sorafenib group; N = 40 patients). The primary outcome was the overall survival (Kaplan-Meier analysis and log-rank test). RESULTS Median overall survival was 320 days (range: 70-420 days) in re-TACE subgroup and 285 days (range: 50-368 days) in TACE/Sorafenib subgroup without significant differences between the two groups (log-rank test P = .72; HR = 0.87; 95% IC 0.41-1.87). The survival rate at one year was 43.6% and 32% in the re-TACE and in the TACE/sorafenib groups (P = .12), respectively. Subgroup analysis by gender, number of nodules at baseline and etiology of liver cirrhosis was performed but no differences were found. No statistical difference was observed in the frequency of side effects, but sorafenib was associated with severe diarrhoea in most patients requiring dose reduction. CONCLUSION In our study including HCC patients aged ≥65 years, no differences in survival rate and side effects were found between patients Retreated with further TACE sessions and patients with treatment stage migration to sorafenib after first TACE failure. We included in our analysis a small study population; therefore, larger prospective studies are needed to confirm these findings.

Alzheimer’s disease (AD) is an age-related dementia and neurodegenerative disorder, characterized by Aβ and tau protein deposition impairing learning, memory and suppressing synaptic plasticity of neurons. Increasing evidence suggests that there is a link between the glucose and glutamate alterations with age that down-regulates glucose utilization reducing glutamate levels in AD patients. Deviations in brain energy metabolism reinforce the development of AD by hampering glutamate levels in the brain. Glutamate is a nonessential amino acid and the major excitatory neurotransmitter synthesized from glucose. Alterations in cerebral glucose and glutamate levels precede the deposition of Aβ plaques. In the brain, over 40% of neuronal synapses are glutamatergic and disturbances in glutamatergic function have been implicated in pathophysiology of AD. Nevertheless, targeting the glutamatergic system seems to be a promising strategy to develop novel, improved therapeutics for AD. Here, we review data supporting the involvement of the glutamatergic system in AD pathophysiology as well as the efficacy of glutamatergic agents in this neurodegenerative disorder. We also discuss exciting new prospects for the development of improved therapeutics for this devastating disorder.

After direct-acting antiviral (DAA) approval, a larger number of diabetic patients with chronic HCV infection have been treated. Cardiovascular risk and insulin resistance significantly change after successful clearance of HCV. Therefore, HCV therapy could potentially improve diabetes microvascular complications including nephropathy. We assessed kidney function after antiviral treatment completion in diabetic (N = 96) and non-diabetic patients (N = 187). Assessment of renal function was performed by serum creatinine and estimated glomerular filtration rate (eGFR) at baseline, at treatment completion and 12 weeks after treatment. Subgroup analysis by age, DAA regimen and eGFR stage at baseline was performed. Serum creatinine did not change significantly at any time whereas eGFR significantly improved during time in diabetic patients (baseline 83.7 ml/min/1.73 m2 vs 102.6 ml/min/1.73 m2 at 12 weeks after treatment completion; p = 0.028). Subgroup analysis showed that the improvement was observed particularly in old people with eGFR

In recent years, several non-invasive methods have been developed for staging liver fibrosis in patients with chronic hepatitis C. A 2D-Shear wave elastography (SWE) technique has been recently introduced on the EPIQ 7 US system (ElastQ), but its accuracy has not been validated in patients with chronic hepatitis C virus (HCV) infection. We enrolled 178 HCV patients to assess their liver fibrosis stage with ElastQ software using transient elastography as a reference standard. The best cut-off values to diagnose ≥ F2, ≥ F3, and F4 were 8.15, 10.31, and 12.65 KPa, respectively. Liver stiffness values had a positive correlation with transient elastography (r = 0.57; p < 0.001). The area under the receiver operating characteristics (AUROC) was 0.899 for ≥ F2 (moderate fibrosis), 0.900 for ≥ F3 (severe fibrosis), and 0.899 for cirrhosis. 2D-SWE has excellent accuracy in assessing liver fibrosis in patients with chronic hepatitis C and an excellent correlation with transient elastography.

Iron deficiency (ID) is the most frequent nutritional deficiency in the whole population worldwide, and the second most common cause of anemia in the elderly. The prevalence of anemia is expecting to rise shortly, because of an ageing population. Even though WHO criteria define anemia as a hemoglobin serum concentration

Aging is associated with increased inflammation, particularly in frailty. Indeed, such patient presents increased serum inflammatory markers, such as C-reactive protein and interleukin-6. Interleukin-6 is an important stimulating factor for the production of procalcitonin. The aim of this study is to evaluate the diagnostic reliability of serum PCT in the diagnosis of sepsis in frail elderly patients. Using Fried’s criteria for frailty, 140 older patients hospitalized for any cause were consecutively enrolled and divided in two groups: no-frail (60 patients) and frail (80 patients). Patients were further categorized on the basis of the presence/absence of sepsis. Interleukin-6, procalcitonin and inflammatory indices were sampled at hospital admission. Septic patients from frail and no-frail groups showed higher values of interleukin-6 and procalcitonin. However, focusing on groups without sepsis, a statistically significant difference of interleukin-6 and procalcitonin values among frail and no-frail groups was seen at the post-hoc analysis. In frail group, procalcitonin cut-off of 0.5 ng/ml had a sensibility and specificity, respectively, of 100 and 22%. Through receiver operating characteristic curve (ROC) analysis, we found that procalcitonin serum value of 1.4 ng/ml had better sensibility and specificity (respectively, 93.8 and 84.4%, AUC 0.965). In our study, we confirm the diagnostic reliability of procalcitonin in frail elderly patients for the diagnosis of sepsis. We found that 1.4 ng/ml was the best cut-off in this population.

Objectives To define whether circulating markers of oxidative stress correlate with sarcopenia in terms of glutathione balance and oxidative protein damage, and whether these biomarkers are associated with risk of cardiovascular disease (CVD). Study design Population-based cross-sectional study. 115 out of 347 elderly subjects were classified as non-sarcopenic non-obese (NS-NO), sarcopenic non-obese (S-NO), non-sarcopenic obese (NS-O), and sarcopenic obese (S-O). Main outcome measurements Sarcopenia was defined as a relative skeletal muscle mass index (RASM) 27 for men or >38 for women. The CVD risk was estimated by the carotid intima-media thickness (IMT) and the Framingham score. Blood reduced glutathione (GSH), oxidized glutathione (GSSG), plasma malondialdehyde-(MDA) and 4-hydroxy-2,3-nonenal-(HNE) protein adducts were analyzed. Results Significantly greater blood GSSG/GSH ratio and plasma MDA/HNE protein adducts were observed in sarcopenic than in non-sarcopenic patients. A logistic regression model showed a close relationship between serum HNE and MDA adducts and sarcopenia (OR = 1.133, 95% CI 1.057–1.215, and OR = 1.592, 95% CI 1.015–1.991, respectively). Linear and logistic regression analysis evidenced strong associations between the IMT or the Framingham CVD risk category and blood GSSG/GSH or serum HNE protein adducts in the S-O group. Conclusion Circulating markers of oxidative stress are increased in sarcopenia and related to CVD risk in sarcopenic obesity, suggesting that redox balance analysis would be a useful part of a multidimensional evaluation in aging. Further research is encouraged to support interventional strategies to correct redox imbalance, which might contribute to the prevention or at least limitation of sarcopenia and its co-morbidities.

The present review points out the role of oxidative stress in aging and the potential therapeutic targets of modern antioxidant therapies. Mitochondria are essential for several biological processes including energy production by generating ATP through the electron transport chain (ETC) located on the inner mitochondrial membrane. Due to their relevance in cellular physiology, defects in mitochondria are associated with various human diseases. Moreover, several years of research have demonstrated that mitochondria have a pivotal role in aging. The oxidative stress theory of aging suggests that mitochondria play a key role in aging as they are the main cellular source of reactive oxygen species (ROS), which indiscriminately damage macromolecules leading to an age-dependent decline in biological function. In this review we will discuss the mitochondrial dysfunction occurring in aging. In particular, we will focus on the novel mitochondria targeted therapies and the new selective molecules and nanocarriers technology as potentially effective in targeting mitochondrial dysfunction and diseases involving oxidative stress and metabolic failure.

According to the original Petersen criteria, we investigated the association between endothelial dysfunction and mild cognitive impairment (MCI) by flow-mediated dilation (FMD). We aimed to verify if endothelial dysfunction occurs in MCI and whether vascular factors are implicated in the MCI pathogenesis. This is a cross-sectional study performed on 34 subjects with clinical diagnosis of MCI and 37 controls, older than 60 years. Patients were enrolled from a geriatric outpatient clinic. All the recognized cardiovascular risk factors and an objective state of cognitive impairment were used as exclusion criteria. Cognitive function was evaluated using a scientific-validated neuropsychological battery, whereas MCI was recognized according to the Petersen criteria. Endothelial function was evaluated according to FMD from the brachial artery. The association between FMD and MCI was evaluated both by using a multivariate analysis and a correlation test. Finally, using the ANOVA analysis of variance, we tested the differences in flow-mediated dilation among MCI subgroups. Brachial FMD was significantly associated with MCI (p

Aging is a physiologic state in which a progressive decline of organ functions may be accompanied by developing age-related diseases and neurodegenerative diseases. The causes of such conditions remain unknown, being probably related to a multifactor process. To date, the Free Radical and Mitochondrial theories seem to be the two most prominent that could explain both how and why aged people develop certain disorders, providing a rationale for treatment. Several reports demonstrate that mitochondria play a key role in aging and some neurodegenerative diseases. Damaged mitochondria produce increased amounts of Reactive Oxygen Species (ROS), leading, in turn, to progressive augmentation in damage. Dysfunctional mitochondria enhance susceptibility to cell death. Indeed, at cell level mitochondria act as an energetic hub determining cell final fate through caspase-dependent apoptosis. Thus, if aging results from oxidative stress, it may be corrected by environmental, nutritional and pharmacological strategies. In this review we summarize the role of mitochondria dysfunction occurring in aging and neurodegenerative disease, describing novel mitochondria-targeted therapy approach and the new selective molecules and nanocarriers technology as potentially effective in targeting mitochondrial dysfunction.

Frailty Syndrome (FS) is a condition described in aging and characterized by physical vulnerability to stress and lack of physiological reserve. In this study we aim to define whether circulating oxidative stress correlates to frailty in terms of glutathione balance and oxidative protein damage. In 62 elderly outpatients, classified as frail patients according to Fried's criteria, evaluation of reduced Glutathione (GSH), Oxidized Glutathione (GSSG), Tumor Necrosis Factor-α (TNF-α), Malonaldehyde- (MDA) and 4-hydroxy-2,3-nonenal- (HNE) protein plasma adducts were performed. A significant increase in the GSSG was observed in patients with FS when compared to non-frail. No difference was shown in the GSH amount, suggesting a glutathione oxidation more than impairment of the synthesis. TNF-α, MDA- and HNE- adducts, were significantly higher in FS as compared to non-frail patients. A logistic regression model correlating FS with redox balance showed a close relationship between glutathione ratio (OR= 1.8, 95% CI=1.2–2.5) and MDA adducts (OR= 2.8, 95% CI= 1.6–4.7) to frailty. Our findings show an association between oxidative imbalance and Frailty Syndrome. GSSG/GSH ratio and plasma protein adducts strongly predict the frailty conditions and seem to be reliable and easily measurable markers in the context of the multidimensional analysis of elderly patients.

Background: The mechanisms of progression from fatty liver to steatohepatitis and cirrhosis are not well elucidated. Mitochondrial dysfunction represents a key factor in the progression of non-alcoholic steatohepatitis (NASH) as mitochondria are the main cellular site of fatty acid oxidation, ATP synthesis and reactive oxygen species (ROS) production. Aims: (1) To evaluate the role of the uncoupling protein 2 in controlling mitochondrial proton leak and ROS production in NASH rats and humans; and (2) to assess the acute liver damage induced by ischaemia–reperfusion in rats with NASH. Methods: Mitochondria were extracted from the livers of NASH humans and rats fed a methionine and choline deficient diet. Proton leak, H 2 O 2 synthesis, reduced glutathione/oxidised glutathione, 4-hydroxy-2-nonenal (HNE)–protein adducts, uncoupling protein-2 (UCP2) expression and ATP homeostasis were evaluated before and after ischaemia–reperfusion injury. Results: NASH mitochondria exhibited an increased rate of proton leak due to upregulation of UCP2. These results correlated with increased production of mitochondrial hydrogen peroxide and HNE–protein adducts, and decreased hepatic ATP content that was not dependent on mitochondrial ATPase dysfunction. The application of an ischaemia–reperfusion protocol to these livers strongly depleted hepatic ATP stores, significantly increased mitochondrial ROS production and impaired ATPase activity. Livers from patients with NASH exhibited UCP2 over-expression and mitochondrial oxidative stress. Conclusions: Upregulation of UCP2 in human and rat NASH liver induces mitochondrial uncoupling, lowers the redox pressure on the mitochondrial respiratory chain and acts as a protective mechanism against damage progression but compromises the liver capacity to respond to additional acute energy demands, such as ischaemia–reperfusion. These findings suggest that UCP2-dependent mitochondria uncoupling is an important factor underlying events leading to NASH and cirrhosis.

Background.Severalrecentstudieshaveshownthatabrief ischaemia applied during the onset of reperfusion (postconditioning) is cardioprotective in different animal models. The potential application of postconditioning to organs different from the heart, i.e. kidney, is not available and is investigated in the present study. We also tested the hypothesis that mitochondria play a central role in renal protection during reperfusion. Methods. Wistar rats were subjected to left nephrectomy and 90-min right kidney occlusion. In controls, the blood flow was restored without intervention. In postconditioned rats, complete reperfusion was preceded by 3 min, 6 min and 12 min of reperfusion in a consecutive sequence, each separated by 5 min of reocclusion. Animals were studied for 48 h. Mitochondrial respiratory chain function, rate of hydroperoxide production and carbonyl proteins were measured at the end of postconditioning and 24 h and 48 h after reperfusion. Results. BUN and creatinine significantly decreased in the postconditioning group as compared to control rats. Mitochondrial respiratory function was significantly impaired in control rats, mainly at the level of Complex II. Postconditioning significantly reduced this mitochondria impairment. The rate of mitochondrial peroxide production was higher in the control group than in the protected groupattheendofpostconditioningreperfusion.Moreover, mitochondrial protein oxidation was significantly higher in control rats than in the postconditioning group at the end of reperfusion. Conclusions. In the present study, postconditioning reduced renal functional injury and reduces mitochondria respiratory chain impairment, mitochondria peroxide production and protein damage.

During the past decade, the knowledge of clinical course and management of hepatitis C virus (HCV) infection has increased enormously, but there are few data on the course of the disease and its treatment in the elderly population (age > 60 years). According to its epidemiology, we are now facing HCV infection from the 20th century. We must take into account that in contrast to a younger population, old people who will develop Chronic C Hepatitis will be mainly women with genotype 1 and more severe fibrosis as clinical presentation pattern.

An increased mitochondrial proton leak occurs in aging, but the origin of such modification remains unclear. This study defined the cause of mitochondrial uncoupling in mitotic (liver) and postmitotic (heart) rat tissues during aging and its effects on energy homeostasis and free radical production. Proton leak in old heart mitochondria was dependent on uncoupling proteins' upregulation, whereas it was caused by alterations in the mitochondrial membrane composition in old liver. ATP homeostasis was impaired in both tissues from old animals and was associated to disrupted F0F1-ATPase activity. H2O2 production rate and 4-hydroxy-2-nonenalprotein adducts were higher in old liver mitochondria compared with young liver mitochondria, but they were similar in heart mitochondria from both groups. Moreover, key mitochondrial biogenesis regulators were upregulated in old liver but downregulated in old heart. In conclusion, uncoupling proteins mediate proton leak and avoid oxidative damage in heart, acting as a protective mechanism. This does not occur in liver, where ATP depletion and oxidative stress may stimulate mitochondrial biogenesis and eliminate damaged cells.

Deficits in glutamate neurotransmission and mitochondrial functions were detected in the frontal cortex (FC) and hippopcampus (HIPP) of aged 3×Tg-Alzheimer's disease (AD) mice, compared with their wild type littermates (non-Tg). In particular, basal levels of glutamate and vesicular glutamate transporter 1 (VGLUT1) expression were reduced in both areas. Cortical glutamate release responded to K(+) stimulation, whereas no peak release was observed in the HIPP of mutant mice. Synaptosomal-associated protein 25 (SNAP-25), glutamate/aspartate transporter (GLAST), glutamate transporter 1 (GLT1) and excitatory amino acid carrier 1 (EAAC1) were reduced in HIPP homogenates, where the adenosine triphosphate (ATP) content was lower. In contrast, glutamate transporter 1 and glial fibrillary acidic protein (GFAP) were found to be higher in the frontal cortex. The respiration rates of complex-I, II, IV, and the membrane potential were reduced in cortical mitochondria, where unaltered proton leak, F(0)F(1)-ATPase activity and ATP content, with increased hydrogen peroxide production (H(2)O(2)), were also observed. In contrast, complex-I respiration rate was significantly increased in hippocampal mitochondria, together with increased proton leak and H(2)O(2) production. Moreover, loss of complex-IV and F(0)F(1)-ATPase activities were observed. These data suggest that impairments of mitochondrial bioenergetics might sustain the failure in the energy-requiring glutamatergic transmission.

The role played by oxidative stress in amiodarone-induced mitochondrial toxicity is debated. Dronedarone shows pharmacological properties similar to those of amiodarone but several differences in terms of toxicity. In this study, we analyzed the effects of the two drugs on liver mitochondrial function by administering an equivalent human dose to a rat model. Amiodarone increased mitochondrial H(2)O(2) synthesis, which in turn induced cardiolipin peroxidation. Moreover, amiodarone inhibited Complex I activity and uncoupled oxidative phosphorylation, leading to a reduction in the hepatic ATP content. We also observed a modification of membrane phospholipid composition after amiodarone administration. N-acetylcysteine completely prevented such effects. Although dronedarone shares with amiodarone the capacity to induce uncoupling of oxidative phosphorylation, it did not show any of the oxidative effects and did not impair mitochondrial bioenergetics. Our data provide important insights into the mechanism of mitochondrial toxicity induced by amiodarone. These results may greatly influence the clinical application and toxicity management of these two antiarrhythmic drugs.

Mitochondrial dysfunction and oxidative stress are determinant events in the pathogenesis of nonalcoholic steatohepatitis. Silybin has shown antioxidant, anti-inflammatory, and antifibrotic effects in chronic liver disease. We aimed to study the effect of the silybin-phospholipid complex (SILIPHOS) on liver redox balance and mitochondrial function in a dietary model of nonalcoholic steatohepatitis. To accomplish this, glutathione oxidation, mitochondrial oxygen uptake, proton leak, ATP homeostasis, and H(2)O(2) production rate were evaluated in isolated liver mitochondria from rats fed a methionine- and choline-deficient (MCD) diet and the MCD diet plus SILIPHOS for 7 and 14 weeks. Oxidative proteins, hydroxynonenal (HNE)- and malondialdehyde (MDA)-protein adducts, and mitochondrial membrane lipid composition were also measured. Treatment with SILIPHOS limited glutathione depletion and mitochondrial H(2)O(2) production. Moreover, SILIPHOS preserved mitochondrial bioenergetics and prevented mitochondrial proton leak and ATP reduction. Finally, SILIPHOS limited the formation of HNE- and MDA-protein adducts. In conclusion, SILIPHOS is effective in preventing severe oxidative stress and preserving hepatic mitochondrial bioenergetics in nonalcoholic steatohepatitis induced by the MCD diet. The modifications of mitochondrial membrane fatty acid composition induced by the MCD diet are partially prevented by SILIPHOS, conferring anti-inflammatory and antifibrotic effects. The increased vulnerability of lipid membranes to oxidative damage is limited by SILIPHOS through preserved mitochondrial function.

Background Mitochondrial dysfunction is considered a key player in non-alcoholic steatohepatitis (NASH) but no data are available on the mitochondrial function and ATP homeostasis in the liver during NASH progression. In the present paper we evaluated the hepatic mitochondrial respiratory chain activity and ATP synthesis in a rodent model of NASH development. Materials and methods Male Wistar rats fed a High Fat/Methionine-Choline Deficient (MCD) diet to induce NASH or a control diet (SHAM), and sacrificed after 3, 7 and 11 weeks. The oxidative phosphorylation, the F(0)F(1)ATPase (ATP synthase) and the ATP content were assessed in liver mitochondria. Results NASH mitochondria exhibited an increased rate of substrate oxidation at 3 weeks, which returned to below the normal level at 7 and 11 weeks, concomitantly with the coupling between the phosphorylation activity and the mitochondrial respiration (ADP/O). Uncoupling of NASH liver mitochondria did not allow the recovery of the maximal respiration rate at 7 and 11 weeks. The ATPase (ATP synthase) activity was similar in NASH and SHAM rats, but the mitochondrial ATP content was significantly lower in NASH livers. Conclusions The loss of hepatic ATP stores is not dependent on the F(0)F(1)-ATPase but resides in the respiratory chain. Dysfunction of both Complex I and II of the mitochondrial respiratory chain during NASH development implies a mitochondrial adaptive mechanism occurring in the early stages of NASH.

Aging is associated with a decline in performance in many organs and loss of physiological performance can be due to free radicals. Mitochondria are incompletely coupled: during oxidative phosphorylation some of the redox energy is dissipated as natural proton leak across the inner membrane. To verify whether proton leak occurs in mitochondria during aging, we measured the mitochondrial respiratory chain activity, membrane potential and proton leak in liver, kidneys and heart of young and old rats. Mitochondria from old rats showed normal rates of Complex I and Complex II respiration. However, they had a lower membrane potential compared to mitochondria from younger rats. In addition, they exhibited an increased rate of proton conductance which partially dissipated the mitochondrial membrane potential when the rate of electron transport was suppressed. This could compromise energy homeostasis in aging cells in conditions that require additional energy supply and could minimize oxidative damage to DNA.