The effects of exogenous l-carnitine on lipid peroxidation and tissue damage in an experimental warm hepatic ischemia-reperfusion injury model

Impact of polyphenol-loaded edible starch nanomaterials on antioxidant capacity and gut microbiota

Starch nanoparticles (SNPs) have the capability to adsorb polyphenol components from apple pomace efficiently, forming bound polyphenols (P-SNPs). These bound polyphenols may have potential bioactivities to affect human health positively. Therefore, in-depth in vivo observation of the antioxidant activity and evaluation of its gut microbiota regulatory function are essential. The results revealed that P-SNPs indicated significant scavenging abilities against DPPH, ABTS, and hydroxyl radicals. Furthermore, the nanomaterials exhibited non-toxic properties, devoid of hepatorenal and intestinal damage, while concurrently stimulating the production of short-chain fatty acids (SCFAs) within the gastrointestinal tract. Notably, P-SNPs significantly enhanced antioxidant capacity in serum, liver, and kidney tissues, fostering the proliferation of beneficial bacteria (Lactobacillus, Bacillus, norank_f__Muribaculaceae) while suppressing pathogenic bacterial growth (Helicobacter, Odoribacter). This study proposes a novel research concept for the scientific use of polyphenols in promoting gut health.

Normalization of lipid oxidation defects arising from hypoxia early posthepatectomy prevents liver failure in mouse

Surgical liver failure (SLF) develops when a marginal amount of hepatic mass is left after surgery, such as following excessive resection. SLF is the commonest cause of death due to liver surgery; however, its etiology remains obscure. Using mouse models of standard hepatectomy (sHx) (68%, resulting in full regeneration) or extended hepatectomy (eHx) (86%/91%, causing SLF), we explored the causes of early SLF related to portal hyperafflux. Assessing the levels of HIF2A with or without oxygenating agent inositol trispyrophosphate (ITPP) indicated hypoxia early after eHx. Subsequently, lipid oxidation (PPARA/PGC1α) was downregulated and associated with persisting steatosis. Mild oxidation with low-dose ITPP reduced the levels of HIF2A, restored downstream PPARA/PGC1α expression along with lipid oxidation activities (LOAs), and normalized steatosis and other metabolic or regenerative SLF deficiencies. Promotion of LOA with L-carnitine likewise normalized the SLF phenotype, and both ITPP and L-carnitine markedly raised survival in lethal SLF. In patients who underwent hepatectomy, pronounced increases in serum carnitine levels (reflecting LOA) were associated with better recovery. Lipid oxidation thus provides a link between the hyperafflux of O₂-poor portal blood, the metabolic/regenerative deficits, and the increased mortality typifying SLF. Stimulation of lipid oxidation-the prime regenerative energy source-particularly through L-carnitine may offer a safe and feasible way to reduce SLF risks in the clinic.

l-carnitine: Nutrition, pathology, and health benefits

Carnitine is a medically needful nutrient that contributes in the production of energy and the metabolism of fatty acids. Bioavailability is higher in vegetarians than in people who eat meat. Deficits in carnitine transporters occur as a result of genetic mutations or in combination with other illnesses such like hepatic or renal disease. Carnitine deficit can arise in diseases such endocrine maladies, cardiomyopathy, diabetes, malnutrition, aging, sepsis, and cirrhosis due to abnormalities in carnitine regulation. The exogenously provided molecule is obviously useful in people with primary carnitine deficits, which can be life-threatening, and also some secondary deficiencies, including such organic acidurias: by eradicating hypotonia, muscle weakness, motor skills, and wasting are all improved l-carnitine (LC) have reported to improve myocardial functionality and metabolism in ischemic heart disease patients, as well as athletic performance in individuals with angina pectoris. Furthermore, although some intriguing data indicates that LC could be useful in a variety of conditions, including carnitine deficiency caused by long-term total parenteral supplementation or chronic hemodialysis, hyperlipidemias, and the prevention of anthracyclines and valproate-induced toxicity, such findings must be viewed with caution.

L-Carnitine and Potential Protective Effects Against Ischemia-Reperfusion Injury in Noncardiac Organs: From Experimental Data to Potential Clinical Applications

The mechanism of ischemia-reperfusion (I/R) injury is complex and multifactorial. In this condition, systemic event results in morbidity and mortality in several pathologies, including myocardial infarction, ischemic stroke, acute kidney injury, trauma, and circulatory arrest. Hypoxia over ischemia phase leads to energy imbalance and changes of cellular homeostasis and functional or structural alterations. In addition, during the reperfusion period, some events, including calcium influx, release of intracellular enzymes, and cell membrane integrity breakdown, cause cell death. L-carnitine (LC) and its derivatives have been suggested to improve tolerance against I/R injury in various tissues. The favorable effects of LC are possibly mediated by its antioxidant and anti-inflammatory effects or by other capability due to increase in the intracellular carnitine content. In this article, anti-ischemic properties of LC and its derivative in noncardiac organs are reviewed using relative animal and human research. Although most of the studies on noncardiac internal organs have shown protective effects of LC administration against I/R injury, more clinical trials are needed to clarify the clinical importance of LC as a treatment option for I/R-induced injury.

Potential Use of Chemoprotectants against the Toxic Effects of Cyanotoxins: A Review

Cyanobacterial toxins, particularly microcystins (MCs) and cylindrospermopsin (CYN), are responsible for toxic effects in humans and wildlife. In order to counteract or prevent their toxicity, various strategies have been followed, such as the potential application of chemoprotectants. A review of the main substances evaluated for this aim, as well as the doses and their influence on cyanotoxin-induced toxicity, has been performed. A search of the literature shows that research on MCs is much more abundant than research on CYN. Among chemoprotectants, antioxidant compounds are the most extensively studied, probably because it is well known that oxidative stress is one of the toxic mechanisms common to both toxins. In this group, vitamin E seems to have the strongest protectant effect for both cyanotoxins. Transport inhibitors have also been studied in the case of MCs, as CYN cellular uptake is not yet fully elucidated. Further research is needed because systematic studies are lacking. Moreover, more realistic exposure scenarios, including cyanotoxin mixtures and the concomitant use of chemoprotectants, should be considered.

Dietary l-carnitine prevents histopathological changes in tilapia (Oreochromis Niloticus) exposed to cylindrospermopsin

Cylindrospermopsin (CYN) is a cytotoxin highly water-soluble, which is easily taken up by several aquatic organisms. CYN acts as a potent protein and glutathione synthesis inhibitor, as well as inducing genotoxicity, oxidative stress, and histopathological alterations. This is the first study reporting the protective effect of a l-carnitine (LC) pretreatment (400 or 880 mg LC/kg bw fish/day, for 21 days) on the histopathological alterations induced by pure CYN or Aphanizomenon ovalisporum lyophilized cells (400 µg CYN/kg bw fish) in liver, kidney, heart, intestines, and gills of tilapia (Oreochromis niloticus) acutely exposed to the toxin by oral route. The main histopathological changes induced by CYN were disorganized parenchyma with presence of glycogen and lipids in the cytoplasm (liver), glomerulonephritis, glomerular atrophy, and dilatation of Bowman's capsule (kidney), myofibrolysis, loss of myofibrils, with edema and hemorrhage (heart), intestinal villi with necrotic enterocytes and partial loss of microvilli (gastrointestinal tract), and hyperemia and hemorrhage (gills). LC pretreatment was able to totally prevent those CYN-induced alterations from 400 mg LC/kg bw fish/day in almost all organs, except in the heart, where 880 mg LC/kg bw fish/day were needed. In addition, the morphometric study indicated that LC managed to recover totally the affectation in the cross sections of the proximal and distal convoluted tubules in CYN-exposed fish. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 241-254, 2017.

The histopathologic effects of L-carnitine in Sodium Taurocholate Induced Severe Pancreatitis Model

OBJECTIVE

To evaluate the histopathologic effects of L-carnitine (LC) in an experimental severe pancreatitis (SP) model induced with sodium taurocholate (STC).

SUMMARY OF BACKGROUND DATA

LC is an amino acid-like molecule that plays an active role in transporting fatty acids and producing Acetyl CoA in mitochondrial matrix for β-oxidation to provide energy which is needed for metabolism. It has ameliorative effects on cell injury demonstrated in many studies. The present study focuses on evaluating histopathologic effects of LC in an experimental SP model.

METHODS

This experimental study in rats was conducted at the Experimental Animal Research Laboratory of the Faculty of Medicine of Inonu University, Malatya, Turkey. Thirty-two Spraque-dawley male rats were divided into 4 groups in a randomized fashion: control (C) group, L-carnitine (LC) group, pancreatitis (P) group, pancreatitis and L-carnitine (P+LC) group. Pancreatitis was induced by a retrograde pancreatic duct injection of 4% sodium taurocholate and L-carnitine was administered 200 mg/kg/day in treatment group. Rats were euthanized with cardiac puncture under anesthesia at 48th hour of the experiment for biochemical and histopathological examination.

RESULTS

In (P+LC) group, the histopathological findings of the pancreatitis were markedly reduced. Acinar cell degeneration was rarely seen. Interlobular and intralobular inflammation and edema was generally mild. The pancreatic damage score of (P+LC) group was significantly lower than that of the (P) group (p<0.05).

CONCLUSION

This study revealed that l-carnitine has a significant histopathologic protective effect on acinar cell degeneration in STC-induced SP model in rats.

Effects of nebivolol on skin flap survival: A randomized experimental study in rats

BACKGROUND

Skin flaps are among the basic treatment options in the reconstruction of soft tissue defects. To improve skin flap survival, a variety of methods, including pharmacologic agents, have been investigated. The effectiveness of anticoagulants, antioxidants, anti-inflammatory drugs, and vasodilatory drugs in improving flap survival has been studied. Nebivolol is a new-generation selective β1-adrenoreceptor blocking agent that has vasodilatory, antithrombotic, antioxidative, and anti- inflammatory effects.

OBJECTIVE

The aim of this experimental study was to investigate the effects of nebivolol (50 mg/kg/d) on random pattern skin flap survival in rats.

METHODS

Male Wistar rats weighing 290 to 310 g were randomly divided into 2 groups-the nebivolol group and the control group. Random patterned, caudally-based, ~3 × 10-cm skin flaps were elevated on the back of each rat. In the nebivolol group, nebivolol 50 mg/kg/d (1 mL, of a racemic solution of nebivolol) was administered orally 2 days before surgery to reach steady-state drug blood concentrations and was continued for 6 days. In the control group, 1 mL/d of sterile saline solution was orally administered 2 days before surgery and was continued for 6 days. To observe the effects of nebivolol, cutaneous blood flow was examined using a laser Doppler flow-meter before and after surgery on days 1, 3, 5, and 7, and flap tissue, malondialdehyde (MDA) and glutathione (GSH) concentrations, and superoxide dismutase (SOD) activity were measured 7 days postsurgery. Flap viability was evaluated 7 days after surgery by measuring necrotic flap area and total flap area.

RESULTS

All 20 rats (nebivolol group, n = 10; control group, n = 10) survived throughout the study period. Mean (SD) MDA concentration was significantly lower in the nebivolol group than in the control group (69.25 [5.82] vs 77.67 [6.87] nmol/g tissue; P = 0.009). GSH concentration was significantly higher in the nebivolol group than in the control group (2.14 [0.15] vs 1.88 [0.22] nmol/mg tissue; P = 0.004). SOD activity was significantly greater in the nebivolol group than in the control group (49.28 [5.49] vs 42.09 [4.95] U/g tissue; P = 0.007). The percentage of the flap that was necrotic was significantly lower in the nebivolol group than in the control group (40.27 [4.08] vs 48.87 [6.35]; P = 0.007).

CONCLUSIONS

This small, experimental, in vivo animal study found that nebivolol was associated with reduced necrotic random pattern skin flap area. Further studies are needed to clarify these findings.

The protective role of l-carnitine against cylindrospermopsin-induced oxidative stress in tilapia (Oreochromis niloticus)

Cylindrospermopsin (CYN) is one of the most important cyanotoxins in terms of both human health and environmental quality and is produced by several different species of cyanobacteria, including Aphanizomenon ovalisporum. The principal mechanisms of action of CYN involve inhibition of protein and glutathione synthesis. In addition, CYN-mediated genotoxicity results from DNA fragmentation. The results of both in vivo and in vitro studies suggest that oxidative stress also plays a significant role in CYN pathogenesis in fish. We investigated the protective effects of l-carnitine (LC) pre-treatment on A. ovalisporum-induced oxidative stress in cells containing CYN and deoxy-CYN, or pure standard CYN, in tilapia (Oreochromis niloticus) that had been acutely exposed via oral administration. Various oxidative stress markers, including lipid peroxidation (LPO), protein oxidation, DNA oxidation, and the ratio of reduced glutathione to oxidised glutathione (GSH/GSSG), and the activities of NADPH oxidase, superoxide dismutase (SOD), catalase (CAT), and gamma-glutamyl-cysteine synthetase (γ-GCS), were evaluated in the livers and kidneys of fish in the absence and presence of 400 or 880mgLC/kgfish/day during a 21 day period prior to CYN-intoxication. The results of our study demonstrated for the first time the beneficial antioxidant effects of LC dietary supplementation on oxidative stress status in fish. No pro-oxidant effects were detected at any of the LC doses assayed, suggesting that LC is a chemoprotectant that reduces hepatic and renal oxidative stress and may be effective when used for the prophylaxis and treatment of CYN-related intoxication in fish.