Alpha lipoic acid attenuates inflammatory response during extracorporeal circulation

Biomaterials Designed to Modulate Reactive Oxygen Species for Enhanced Bone Regeneration in Diabetic Conditions

Diabetes mellitus, characterized by enduring hyperglycemia, precipitates oxidative stress, engendering a spectrum of complications, notably increased bone vulnerability. The genesis of reactive oxygen species (ROS), a byproduct of oxygen metabolism, instigates oxidative detriment and impairs bone metabolism in diabetic conditions. This review delves into the mechanisms of ROS generation and its impact on bone homeostasis within the context of diabetes. Furthermore, the review summarizes the cutting-edge progress in the development of ROS-neutralizing biomaterials tailored for the amelioration of diabetic osteopathy. These biomaterials are engineered to modulate ROS dynamics, thereby mitigating inflammatory responses and facilitating bone repair. Additionally, the challenges and therapeutic prospects of ROS-targeted biomaterials in clinical application of diabetic bone disease treatment is addressed.

The effects of alpha lipoic acid (ALA) supplementation on blood pressure in adults: a GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials

Introduction

There have been various clinical studies on the effect of Alpha lipoic acid (ALA) supplementation on blood pressure (BP), but the findings from these are contradictory. Therefore, we performed a systematic review and dose-response meta-analysis to summarize the relation of ALA supplementation and systolic blood pressure (SBP) and diastolic blood pressure (DBP) in adults.

Methods

A comprehensive search was conducted in Medline (PubMed), Embase, Scopus, and ProQuest up to July 2023. Randomized controlled trials (RCTs) evaluating the effect of ALA on SBP and DBP were included. The pooled weighted mean difference (WMD) of included trials was estimated using a random-effects model. The dose-dependent effect was also assessed.

Results and discussion

A total of 11 RCTs with the participation of 674 patients were included. The result of the meta-analysis indicated that using ALA supplementation significantly reduced the SBP (WMD = -5.46 mmHg; 95% CI: -9.27, -1.65; p < 0.001) and DBP (WMD = -3.36 mmHg, 95% CI: -4.99, -1.74; p < 0.001). The ALA administrations significantly reduced SBP and DBP at the dosages of <800 mg/day, when administered for ≤12 weeks. The present meta-analysis revealed that ALA supplementation could exert favorable effects on SBP and DBP. Further well-designed studies with larger samples are needed to ascertain the long-term effects of ALA on BP.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=447658, identifier PROSPERO: CRD42023447658.

Medical nutrition therapy in patients receiving ECMO: Evidence-based guidance for clinical practice

Patients receiving extracorporeal membrane oxygenation (ECMO) inherit substantial disease-associated metabolic, endocrinologic, and immunologic modifications. Along with the technical components of ECMO, the aforementioned alterations may affect patients' needs and feasibility of adequate macronutrient and micronutrient supply and intake. Thus, patients receiving ECMO are at increased risk for iatrogenic malnutrition and require targeted individual medical nutrition therapy (MNT). However, specific recommendations for MNT in patients receiving ECMO are limited and, with some exceptions, based on an evidence base encompassing general patients who are critically ill. Consequently, clinician decision-making for MNT in patients receiving ECMO is unguided, which may further increase nutrition risk, culminating in iatrogenic malnutrition and ultimately affecting patient outcomes. The purpose of this article is to provide educational background and highlight specific points for MNT in adult patients receiving ECMO, which might serve as evidence-based guidance to develop institutional standard operating procedures and nutrition protocols for daily clinical practice.

Combating Ischemia-Reperfusion Injury with Micronutrients and Natural Compounds during Solid Organ Transplantation: Data of Clinical Trials and Lessons of Preclinical Findings

Although extended donor criteria grafts bear a higher risk of complications such as graft dysfunction, the exceeding demand requires to extent the pool of potential donors. The risk of complications is highly associated with ischemia-reperfusion injury, a condition characterized by high loads of oxidative stress exceeding antioxidative defense mechanisms. The antioxidative properties, along with other beneficial effects like anti-inflammatory, antiapoptotic or antiarrhythmic effects of several micronutrients and natural compounds, have recently emerged increasing research interest resulting in various preclinical and clinical studies. Preclinical studies reported about ameliorated oxidative stress and inflammatory status, resulting in improved graft survival. Although the majority of clinical studies confirmed these results, reporting about improved recovery and superior organ function, others failed to do so. Yet, only a limited number of micronutrients and natural compounds have been investigated in a (large) clinical trial. Despite some ambiguous clinical results and modest clinical data availability, the vast majority of convincing animal and in vitro data, along with low cost and easy availability, encourage the conductance of future clinical trials. These should implement insights gained from animal data.

Potential roles of mitochondrial cofactors in the adjuvant mitigation of proinflammatory acute infections, as in the case of sepsis and COVID-19 pneumonia

BACKGROUND

The mitochondrial cofactors α-lipoic acid (ALA), coenzyme Q10 (CoQ10) and carnitine (CARN) play distinct and complementary roles in mitochondrial functioning, along with strong antioxidant actions. Also termed mitochondrial nutrients (MNs), these cofactors have demonstrated specific protective actions in a number of chronic disorders, as assessed in a well-established body of literature.

METHODS

Using PubMed, the authors searched for articles containing information on the utilization of MNs in inflammatory disorders as assessed from in vitro and animal studies, and in clinical trials, in terms of exerting anti-inflammatory actions.

RESULTS

The retrieved literature provided evidence relating acute pathologic conditions, such as sepsis and pneumonia, with a number of redox endpoints of biological and clinical relevance. Among these findings, both ALA and CARN were effective in counteracting inflammation-associated redox biomarkers, while CoQ10 showed decreased levels in proinflammatory conditions. MN-associated antioxidant actions were applied in a number of acute disorders, mostly using one MN. The body of literature assessing the safety and the complementary roles of MNs taken together suggests an adjuvant role of MN combinations in counteracting oxidative stress in sepsis and other acute disorders, including COVID-19-associated pneumonia.

CONCLUSIONS

The present state of art in the use of individual MNs in acute disorders suggests planning adjuvant therapy trials utilizing MN combinations aimed at counteracting proinflammatory conditions, as in the case of pneumonia and the COVID-19 pandemic.

α-Lipoic acid exerts a primary prevention for the cardiac dysfunction in aortocaval fistula-created rat hearts

Aim

α-Lipoic acid exerts a powerful antioxidant effect by acting as a free radical scavenger and inducing endogenous antioxidants such as vitamin E and glutathione. In the present study, we examined the effects of α-lipoic acid on cardiac dysfunction in rat hearts with aortocaval fistulae.

Main methods

Aortocaval fistulae were created between the abdominal aorta and inferior vena cava in male rats. Hemodynamic parameters were measured 14 days after surgery using an intravascular pressure transducer, and then these hearts were harvested for tissue weight measurement, pathological evaluation, and mRNA isolation.

Results

In vehicle-treated rats, left ventricular end-diastolic pressure and left ventricular weight significantly increased at 14 days after fistula creation. Fistula-creation resulted in expression of 4-hydroxy-2-nonenal, NADPH oxidase subunit p67^phox and BNP mRNA in a time-dependent manner in the left ventricle.

Long-term treatment (initiated 2 days before surgery, and continued for 14 days after fistula creation; days -2 to 14) with α-lipoic acid (30 mg/kg/day) markedly suppressed the increases in left and right ventricular weight, and left ventricular end-diastolic pressure. α-Lipoic acid treatment from days -2 to 14 prominently prevented the expression of 4-hydroxy-2-nonenal and NADPH oxidase subunit p67^phox, and significantly raised BNP mRNA levels. Short-term treatment with α-lipoic acid from day - 2 to 7 was effective in preventing cardiac enlargement and dysfunction, similar to long-term treatment, but treatment from days 7–14 was not effective.

Conclusions

Treatment with α-lipoic acid can prevent cardiac hyperplasia and dysfunction, probably by inhibiting superoxide production and enhancing BNP mRNA expression in an early phase after fistula creation.

Oxidative Stress and Neonatal Respiratory Extracorporeal Membrane Oxygenation

Oxidative stress is a frequent condition in critically ill patients, especially if exposed to extracorporeal circulation, and it is associated with worse outcomes and increased mortality. The inflammation triggered by the contact of blood with a non-endogenous surface, the use of high volumes of packed red blood cells and platelets transfusion, the risk of hyperoxia and the impairment of antioxidation systems contribute to the increase of reactive oxygen species and the imbalance of the redox system. This is responsible for the increased production of superoxide anion, hydrogen peroxide, hydroxyl radicals, and peroxynitrite resulting in increased lipid peroxidation, protein oxidation, and DNA damage. The understanding of the pathophysiologic mechanisms leading to redox imbalance would pave the way for the future development of preventive approaches. This review provides an overview of the clinical impact of the oxidative stress during neonatal extracorporeal support and concludes with a brief perspective on the current antioxidant strategies, with the aim to focus on the potential oxidative stress-mediated cell damage that has been implicated in both short and long-term outcomes.

Beneficiary effect of a-lipoic acid supplementation on C-reactive protein level among adults

Purpose

Clinical evidence has suggested that alpha-lipoic acid (ALA), a potent antioxidant, seems to have some effects on inflammatory process. However, these results are equivocal. The purpose of this paper is to investigate the nature of association between ALA and serum C-reactive protein (CRP) level by pooling the results from clinical trial studies.

Design/methodology/approach

Relevant studies were identified by systematic literature search of PubMed/MEDLINE, Scopus, Web of Sciences and Cochrane library up to September 2016 for randomized controlled trials (RCTs) evaluating the impact of ALA supplementation on CRP. The pooled data were summarized as weighted mean difference (WMD) and 95 per cent confidence interval (CI). Effect sizes of eligible studies were pooled using random- or fixed-effects (the DerSimonian–Laird estimator) depending on the results of heterogeneity tests.

Findings

Of 212 papers, 15 were eligible RCTs according to inclusion criteria. The selected studies comprised 1,408 cases and 457 controls. The dose of ALA supplement ranged from 300 to 1,200 mg, and the duration of follow-up was from 1 to 48 weeks. ALA supplementation significantly reduced the levels of circulating CRP (WMD: −0.088, 95 per cent CI: −0.131, −0.045, p < 0.001) with significant heterogeneity (I2 = 73.4 per cent, p < 0.001). Populations with age younger than 50 years (PMD: −0.060 mg/dl), receiving doses less than 600 mg/day (PMD: −0.057 mg/dl), having cardiovascular disease (PMD: −0.105 mg/dl), hemodialysis (PMD: −0.209 mg/dl), diabetes (PMD: −0.021 mg/dl) and otherwise healthy subjects (PMD: −0.045 mg/dl) were sources of heterogeneity.

Originality/Value

This meta-analysis of RCTs suggests that ALA supplementation seems to significantly reduce circulating CRP level.

Burns: Pathophysiology of Systemic Complications and Current Management

As a result of many years of research, the intricate cellular mechanisms of burn injury are slowly becoming clear. Yet, knowledge of these cellular mechanisms and a multitude of resulting studies have often failed to translate into improved clinical treatment for burn injuries. Perhaps the most valuable information to date is the years of clinical experience and observations in the management and treatment of patients, which has contributed to a gradual improvement in reported outcomes of mortality. This review provides a discussion of the cellular mechanisms and pathways involved in burn injury, resultant systemic effects on organ systems, current management and treatment, and potential therapies that we may see implemented in the future.

Control-released Alpha-lipoic acid-loaded PLGA microspheres enhance bone formation in type 2 diabetic rat model

Since diabetes lead to alterations in bone metabolism with reductions in bone mineral content and delayed bone formation, the most effective method for bone regeneration in diabetes remains to be determined. In this study, type 2 diabetes were successfully induced via a high-fat diet and low-dose streptozotocin intraperitoneal injection. Excess reactive oxygen species (ROS) has been implicated in diabetes mellitus. Overexpression of ROS can lead to oxidative stress and subsequently to H₂O₂-mediated impaired proliferation and delayed cellular differentiation. As a result, antioxidant alpha-lipoic acid (ALA)-loaded poly (lactic-co-glycolic acid) (PLGA) microspheres were fabricated using the emulsion solvent evaporation method, and a sustained and controlled release of ALA was observed up to 27 days. It was demonstrated that biodegradable PLGA microspheres loaded with ALA acted as ROS scavengers and partially recover the mesenchymal stem cell proliferation and differentiation. The bone formation of ALA loaded scaffolds in rat cranial bone defects were greater than the prime three-dimensional collagen scaffold. These results suggest the application of ALA loaded PLGA microsphere exhibit good bioactivity and bone forming ability in diabetes.

C1 inhibitor-mediated myocardial protection from chronic intermittent hypoxia-induced injury

The optimal treatment for chronic intermittent hypoxia (CIH)-induced cardiovascular injuries has yet to be determined. The aim of the current study was to explore the potential protective effect and mechanism of a C1 inhibitor in CIH in the myocardium. The present study used a rat model of CIH in which complement regulatory protein, known as C1 inhibitor (C1INH), was administered to the rats in the intervention groups. Cardiomyocyte apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. The expression of proteins associated with the apoptotic pathway, such as B-cell lymphoma 2 (Bcl-2), Bax and caspase-3 were detected by western blot analysis. The expression of complement C3 protein and RNA were also analyzed. C1INH was observed to improve the cardiac function in rats with CIH. Myocardial myeloperoxidase activity, a marker of neutrophil infiltration, was significantly decreased in the C1INH intervention group compared with the CIH control group, and cardiomyocyte apoptosis was significantly attenuated (P<0.05). Western blotting and reverse transcription-polymerase chain reaction analysis indicated that the protein expression levels of Bcl-2 were decreased and those of Bax were increased in the CIH group compared with the normal control group, but the protein expression levels of Bcl-2 were increased and those of Bax were decreased in the C1INH intervention group, as compared with the CIH group. Furthermore, the CIH-induced expression and synthesis of complement C3 in the myocardium were also reduced in the C1INH intervention group. C1INH, in addition to inhibiting complement activation and inflammation, preserved cardiac function in CIH-mediated myocardial cell injury through an anti-apoptotic mechanism.

α-Lipoic Acid Protects Against Ischemia-Reperfusion Injury in Simultaneous Kidney-Pancreas Transplantation

BACKGROUND

Multiple factors have been implicated in the process of ischemia-reperfusion injury (IRI) in organ transplantation. Among these factors, oxidative damage seems to initiate the injury. α-lipoic acid (ALA) is a potent antioxidant that is used in patients with diabetic polyneuropathy. The aim of the present study was to determine the effect of ALA in patients undergoing simultaneous kidney-pancreas transplant by evaluating the functional recovery of the graft and biochemical markers of IRI.

METHODS

Twenty-six patients were included in the following groups: (i) untreated control; (ii) donor and recipient (DR) ALA-treated, in which ALA was administered both to the deceased donor and to the recipients; and (iii) recipient ALA-treated group. The expression of inflammatory genes, as observed in biopsies taken at the end of surgery, as well as the serum cytokines, secretory leukocyte protease inhibitor, regenerating islet-derived protein 3β/pancreatitis-associated protein, amylase, lipase, glucose, and creatinine levels were quantified as markers of organ function.

RESULTS

The DR group showed high levels of TGFβ and low levels of C3 and TNFα in the kidneys, whereas high levels of C3 and heme oxygenase were identified in pancreas biopsies. Decreases in serum IL-8, IL-6, secretory leukocyte protease inhibitor, and regenerating islet-derived protein 3 β/pancreatitis-associated protein were observed after surgery in the DR group. Serum lipase and amylase were lower in the DR group than in the control and recipient groups. Early kidney dysfunction and clinical pancreatitis were higher in the control group than in either treatment group.

CONCLUSIONS

These results show that ALA preconditioning is capable of reducing inflammatory markers while decreasing early kidney dysfunction and clinical posttransplant pancreatitis.

Evaluation of systemic inflammatory response in cardiovascular surgery via interleukin-6, interleukin-8, and neopterin

AIM

The aim of this study was to evaluate the serum levels of interleukin-6 (IL-6), IL-8, and neopterin as a sign of systemic inflammatory response syndrome after open-heart surgery. In this study, we evaluated the influences on the levels of IL-6, IL-8, and neopterin of coronary artery bypass grafting (CABG) and valve replacement surgeries with and without the use of extracorporeal circulation (ECC).

MATERIALS AND METHODS

This prospective study was performed in 30 patients. In this study, we evaluated patients who underwent valve replacement surgery (group 1, n = 10), CABG with ECC (group 2, n = 10), or CABG using the beating-heart technique (group 3, n = 10). With the Human Investigation Ethics Committee consent, blood samples were obtained from the patients before the surgery (T0) and after 1 hour (T1), 4 hours (T2), 24 hours (T3), and 48 hours (T4) of protamine injection. IL-6, IL-8, and neopterin levels were measured using commercial enzyme-linked immunosorbent assay kits.

RESULTS

The demographic data and preoperative and operative characteristics of the patients were similar. Neopterin IL-6 and IL-8 levels significantly increased first at the fourth hour after the surgery. When compared to the levels before the surgery, this increase was statistically significant. Unlike the other 2 groups of patients, those who experienced CABG with the beating-heart technique (group 3) had decreased neopterin levels at the first hour after the surgery, but this decrease was not statistically significant. Neopterin levels increased later in the OPCAB group, but these increased levels were not as high as the neopterin levels of groups 1 and 2. Neopterin reached maximum levels at the 24th hour and, unlike groups 1 and 2, in group started to decrease at the 48th.

CONCLUSIONS

Complement activation, cytokine production, and related cellular responses are important factors during open-heart surgery. It is certain that ECC activates the complement systems, and activated complement proteins cause the production of several cytokines. In our study, neopterin levels in patients who underwent beating-heart method surgery were lower than those in the other groups, and these levels started to decrease at the 48th hour. These data suggest that the systemic inflammatory response was less activated in that patient group. The beating-heart method might be an important alternative in CABG surgery to minimize the complications and mortality related to surgery.

Preoperative CRP levels is not predictive early renal dysfunction after coronary artery bypass surgery

BACKGROUND

The aim of this retrospective study is to determine the correlation between preoperative CRP levels and the early renal dysfunction after cardiac surgery.

METHODS

From January 2012 to December 2013, values for preoperative CRP were available for 546 unselected patients undergoing cardiac operations. CRP was used to divide this cohort in two groups: a normal CRP levels group (Group I) of 432 patients with CRP of less than 0.5 mg/dL, and a high CRP levels group (group II) of 114 patients with a CRP of 0.5 mg/dL or more.

RESULTS

Median CRP preoperative values were significantly different in the group II (2.49±1.03 mg/dL) than in the group I (0.32±0.14 mg/dL; P < 0.0001). Median CRP postoperative values were significantly different in the group I (17.62±2.99) than in the group II (23.13±3.01; P < 0.0001). Preoperative levels of serum blood urea nitrogen (BUN), creatinine and CrCl were not significantly different between group I and group II. Postoperative levels of BUN, Cr and CrCl between the two groups were not significantly different.

CONCLUSIONS

The early Cr and CrCl levels after surgery are not significantly different in group I and group II. The early renal function after CABG is not correlated with the preoperative CRP levels.

The effect of thioctic acid on allodynia in a rat vincristine-induced neuropathy model

Objective

To investigate the antiallodynic effects of thioctic acid in vincristine-induced neuropathy in rats.

Methods

Neuropathy was induced in Sprague–Dawley rats via vincristine intraperitoneal injection. After 15 days, rats were investigated for the presence of mechanical and cold allodynia, and those with allodynia received intraperitoneal injection with normal saline or 1, 5, or 10 mg/kg thioctic acid. Mechanical and cold allodynia were assessed before treatment and at 15, 30, 60, 90, 150 and 180 min after treatment.

Results

Mechanical and cold allodynia were reduced by thioctic acid injection. The duration of effect increased with thioctic acid dose.

Conclusion

Thioctic acid may be an effective treatment for vincristine-induced neuropathy.