Protective effect of aminoguanidine against lipopolysaccharide-induced hepatotoxicity and liver dysfunction in rat

A Narrative Review of Protective Effects of Natural Compounds Against Lipopolysaccharide-Induced Injuries

Lipopolysaccharide (LPS) is a large amphipathic glycoconjugate molecule in the cell wall of Gram-negative bacteria. This bacterial endotoxin binds to toll-like receptor 4 (TLR4) and stimulates the inflammatory reactions and oxidative stress. The current paper presents the protective effects of natural compounds against LPS-induced injuries. The relevant findings were extracted from PubMed, Web of Science, Scopus, and Google Scholar databases from the beginning of 2005 until the end of September 2023 were employed. The results of in vitro and in vivo studies indicated that thymoquinone, crocin, carvacrol, and quercetin effectively attenuated LPS-induced damages via lowering the level of inflammatory cytokines and free radicals. These natural compounds could also amplify the antioxidant defense against LPS by increasing the activity of antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT). In addition, a part of the protective effects of these phytochemicals against detrimental impacts of LPS is attributed to their ability to downregulate the TLR4 expression and to inhibit the NF-κB signaling pathway. Briefly, the protective effects of natural compounds mentioned in current review against LPS-caused damages mainly are mediated by their anti-inflammatory and antioxidant activities.

Toxicity effects of microplastics individually and in combination with Aeromonas hydrophila on freshwater crayfish (Astacus leptodactylous)

Opportunistic pathogens, such as Aeromonas hydrophila, can cause damage to freshwater crayfish (Astacus leptodactylous) in some situations. In addition to direct damage to the body, microplastics (MPs) can also be responsible for transmitting pathogens to the animal. Accordingly, this research was prepared to investigate the effects of MP on the damage caused by A. hydrophila exposure in A. leptodactylous. Hepatic oxidative biomarkers, blood biochemical indices, and clinical signs were investigated in freshwater crayfish co-exposed to MPs (500 and 1000 mg kg-1) and A. hydrophila (5 and 10% of the median lethal dose (LD50)) for 30 days. In the hemolymph of infested crayfish with A. hydrophila, there were no significant changes in glutathione peroxidase activity or total antioxidant level. However, in some of the clinical parameters, exposure to MP alone had a significant effect. Cholesterol levels, glutathione peroxidase, catalase, and the activity of γ-glutamyltransferase reduced, conversely, glucose, malondialdehyde, and aspartate aminotransferase increased. After co-exposure to A. hydrophila and MPs, certain parameters elevated in the hemolymph of crayfish such as glucose, activity of alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase. However, total protein, cholesterol, γ-glutamyltransferase, glutathione peroxidase, catalase activity, and total antioxidants decreased. In contrast, elevation in malondialdehyde content and superoxide dismutase activity was observed in the hepatocytes of crayfish after co-exposure to A. hydrophila and MPs. To summarize, the investigation demonstrated that the interaction of MPs and A. hydrophila in crayfish has a synergistic effect on various factors.

Pioglitazone ameliorates sepsis-associated encephalopathy through SIRT1 signaling pathway

Sepsis is a severe immune response to an infection. It is associated with multiple organ dysfunction syndrome (MODs) along with systemic and neuronal inflammatory response. This study focused on the acute neurologic dysfunction associated with sepsis by exploring the role of PPARγ/SIRT1 pathway against sepsis. We studied the role of this axis in ameliorating sepsis-associated encephalopathy (SAE) and its linked neurobehavioral disorders by using pioglitazone (PIO). This PPARγ agonist showed neuroprotective actions in neuroinflammatory disorders. Sepsis was induced in mice by LPS (10 mg/kg). Survival rate and MODs were assessed. Furthermore, behavioral deficits, cerebral oxidative, inflammatory, and apoptotic markers, and the cerebral expression level of SIRT1 were determined. In this study, we observed that PIO attenuated sepsis-induced cerebral injury. PIO significantly enhanced survival rate, attenuated MODs, and systemic inflammatory response in septic mice. PIO also promoted cerebral SIRT1 expression and reduced cerebral activation of microglia, oxidative stress, HMGB, iNOS, NLRP3 and caspase-3 along with an obvious improvement in behavioral deficits and cerebral pathological damage induced by LPS. Most of the neuroprotective effects of PIO were abolished by EX-527, a SIRT1 inhibitor. These results highlight that the neuroprotective effect of PIO in SAE is mainly SIRT1-dependent.

Prophylactic and Therapeutic Efficacy of Boric Acid on Lipopolysaccharide-Induced Liver and Kidney Inflammation in Rats

In our study, we aimed to examine possible prophylactic (P) or therapeutic (T) effects of boric acid (BA) on lipopolysaccharide (LPS) induced liver and kidney damages. Thirty-two rats were divided into four groups as control, LPS, BAP+LPS, and LPS+BAT. BA was given orally to the rats one hour before the intraperitoneal LPS administration in the BAP+LPS group and one hour after the LPS administration in the LPS+BAT group. Malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-6 (IL-6), IL-10, reduced glutathione (GSH), total oxidant and antioxidant status (TOS and TAS), semaphorin-3A (SEMA3A), cytochrome c (CYCS), and caspase-3 (CASP3) parameters were determined by ELISA method to monitor inflammation, oxidative stress, and apoptosis in the liver and kidney tissues of rats. In addition, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, creatinine (CREA), C-reactive protein (CRP), gamma glutamyl transferase (GGT), glucose (GLU), sodium (Na), potassium (K), and chlorine (Cl) biochemical parameters were measured in rat serums to monitor liver and kidney functions. Liver and kidney tissues were also examined histopathologically and immunohistochemically. All data were statistically analyzed. Our histological, biochemical, inflammatory, oxidative stress, and apoptotic findings showed that LPS causes serious damage to liver and kidney tissues. Boric acid application brought about significant improvements on the parameters. However, this improvement was seen in the BAP+LPS group, and the results of the LPS+BAT group were insufficient to improve. Our results showed that boric acid administration is effective on severe liver and kidney damage caused by LPS. It has been concluded that prophylactic application is more effective, while therapeutic application is insufficient.

Nano-selenium relieved hepatic and renal oxidative damage in hypothyroid rats

Hypothyroidism can induce oxidative stress. Nano-selenium (Nano Sel) has antioxidant effects. The current research explored Nano Sel effects on hepatic and renal oxidative damage induced by hypothyroidism in rats. Animals were grouped into (1) Control; (2) Propylthiouracil (PTU) group which received water mixed with 0.05% of PTU; (3) PTU-Nano Sel 50; (4) PTU-Nano Sel 100; and (5) PTU-Nano Sel 150. Besides PTU, the PTU-Nano Sel groups were treated with 50, 100, or 150 μg/kg of Nano Sel intraperitoneally. Treatments were done for 6 weeks. The serum level of T4, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), albumin, total protein, creatinine, and blood urea nitrogen (BUN) was evaluated. Malondialdehyde (MDA) and total thiol concentration and the activity of catalase (CAT) and superoxide dismutase (SOD) in hepatic and renal tissues also were checked. Hypothyroidism induced by PTU significantly increased AST, ALT, ALP, creatinine, BUN, and MDA concentration and noticeably reduced albumin, total protein, total thiol level, and SOD and CAT activity. Administration of Nano Sel ameliorated the adverse effects of hypothyroidism on liver and kidney function. Nano Sel applied protective effects against hepatic and renal damage resulting from hypothyroidism via ameliorating the oxidative stress status. More cellular and molecular experiments need to be done to understand the exact mechanisms.

Effects of Herbs and Derived Natural Products on Lipopolysaccharide-Induced Toxicity: A Literature Review

Introduction

Oxidative stress (OS) during inflammation can increase inflammatory responses and damage tissue. Lipopolysaccharide (LPS) can induce oxidative stress and inflammation in several organs. Natural products have several biological activities including anti-inflammatory, antioxidant, and immunoregulatory properties. The aims of the study are to study the possible therapeutic effects of natural products on LPS inducing toxicity on the nervous system, lung, liver, and immune system.

Methods

The in vitro and in vivo research articles that were published in the last 5 years were included in the current study. The keywords included "lipopolysaccharide," "toxicity," "natural products," and "plant extract" were searched in different databases such as Scopus, PubMed, and Google Scholar until October 2021.

Results

The results of most studies indicated that some medicinal herbs and their potent natural products can help to prevent, treat, and manage LPS-induced toxicity. Medicinal herbs and plant-derived natural products showed promising effects on managing and treating oxidative stress, inflammation, and immunomodulation by several mechanisms.

Conclusion

However, these findings provide information about natural products for the prevention and treatment of LPS-induced toxicity, but the scientific validation of natural products requires more evidence on animal models to replace modern commercial medicine.

Selective gene expression profiling contributes to a better understanding of the molecular pathways underlying the histological changes observed after RHMVL

Background

In previous studies, five vasoactive drugs were investigated for their effect on the recovery process after extended liver resection without observing relevant improvements. We hypothesized that an analysis of gene expression could help to identify potentially druggable pathways and could support the selection of promising drug candidates.

Methods

Liver samples obtained from rats after combined 70% partial hepatectomy and right median hepatic vein ligation (n = 6/group) sacrificed at 0 h, 24 h, 48 h, and 7days were selected for this study. Liver samples were collected from differentially perfused regions of the median lobe (obstruction-zone, border-zone, normal-zone). Gene expression profiling of marker genes regulating hepatic hemodynamics, vascular remodeling, and liver regeneration was performed with microfluidic chips. We used 3 technical replicates from each sample. Raw data were normalized using LEMming and differentially expressed genes were identified using LIMMA.

Results

The strongest differences were found in obstruction-zone at 24 h and 48 h postoperatively compared to all other groups. mRNA expression of marker genes from hepatic hemodynamics pathways (iNOS,Ptgs2,Edn1) was most upregulated.

Conclusion

These upregulated genes suggest a strong vasoconstrictive effect promoting arterial hypoperfusion in the obstruction-zone. Reducing iNOS expression using selective iNOS inhibitors seems to be a promising approach to promote vasodilation and liver regeneration.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01364-z.

Effect of microplastics on Yersinia ruckeri infection in rainbow trout (Oncorhynchus mykiss)

Exposure to microorganisms such as Yersinia ruckeri can significantly affect bacterial infections in fish. Microplastics (MPs) may predispose fish to infection and act as carriers in pathogen transmission. Therefore, this study is designed to evaluate MPs' effect on damage caused by exposure to Y. ruckeri in rainbow trout. In this study, blood biochemical parameters and hepatic oxidative biomarkers as clinical signs were measured in the fish co-exposed to Y. ruckeri (5 and 10% the median lethal dose (LD₅₀)) and MPs (500 and 1000 mg Kg^-1) for 30 days. There were no significant changes in the creatinine, triglyceride, cholesterol levels, and glutamic-pyruvic transaminase activity in the blood of fish infected with Y. ruckeri. In contrast, exposure to MPs had a significant effect on most clinical parameters. The total protein, albumin, globulin, total immunoglobulins, high-density lipoprotein, low-density lipoprotein, cholesterol levels, and γ-glutamyltransferase activity decreased, whereas glucose, triglyceride, and creatinine levels, and glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, alkaline phosphatase, and lactate dehydrogenase activities increased in the plasma of fish after co-exposure to MPs and Y. ruckeri. Dietary MPs combined with a Y. ruckeri challenge decreased catalase and glutathione peroxidase activities, and total antioxidant levels. However, superoxide dismutase activity and malondialdehyde contents increased in the hepatocyte of fish co-exposed to MPs and Y. ruckeri. This study suggests that fish exposure to MPs and simultaneous challenge with Y. ruckeri could synergistically affect clinical parameters.

Captopril suppresses hepatic mammalian target of rapamycin cell signaling and biomarkers of inflammation and oxidative stress in thioacetamide-induced hepatotoxicity in rats

BACKGROUND

The potential inhibitory effects of captopril, the angiotensin-converting enzyme inhibitor, on thioacetamide (TAA)-induced hepatic mammalian target of rapamycin (mTOR), liver injury enzymes, blood pressure, and biomarkers of inflammation and oxidative stress have not been investigated before.

MATERIALS AND METHODS

Rats were either injected with TAA (200 mg/kg; twice a week for 8 weeks) before being sacrificed after 10 weeks (model group) or were pretreated with captopril (150 mg/kg) daily for two weeks prior to TAA injections and continued receiving both agents until the end of the experiment (protective group).

RESULTS

Captopril significantly (p < .05) inhibited TAA-induced hypertension, liver tissue levels of mTOR, TIMP-1, TNF-α, IL-6, MDA; and blood levels of lipids, ALT, and AST. We further demonstrated a significant (p < .01) positive correlation between mTOR scoring and the levels of inflammatory, oxidative and liver injury biomarkers.

CONCLUSIONS

Captopril protects against TAA-induced mTOR, liver injury enzymes, dyslipidemia, hypertension, inflammation, and oxidative stress.

Ameliorative role of inducible nitric oxide synthase inhibitors against sodium arsenite-induced renal and hepatic dysfunction in rats

Arsenic exposure causes immense health distress by increasing risk of cardiovascular abnormalities, diabetes mellitus, neurotoxicity, and nephrotoxicity. The present study explored the role of inducible nitric oxide synthase (iNOS) inhibitors against sodium arsenite-induced renal and hepatic dysfunction in rats. Female Sprague Dawley rats were subjected to arsenic toxicity by administering sodium arsenite (5 mg/kg/day, oral) for 4 weeks. The iNOS inhibitors, S-methylisothiourea (10 mg/kg, i.p.) and aminoguanidine (100 mg/kg, i.p.) were given one hour before sodium arsenite administration in rats for 4 weeks. Sodium arsenite led rise in serum creatinine, urea, uric acid, electrolytes (potassium, fractional excretion of sodium), microproteinuria, and decreased creatinine clearance (p < 0.001) indicated renal dysfunction in rats. Arsenic-intoxication resulted in significant oxidative stress in rat kidneys, which was measured in terms of increase in lipid peroxides, superoxide anion generation and decrease in reduced glutathione (p < 0.001) levels. A threefold increase in renal hydroxyproline level in arsenic intoxicated rats indicated fibrosis. Hematoxylin-eosin staining indicated tubular damage, whereas picrosirius red staining highlighted collagen deposition in rat kidneys. S-methylisothiourea and aminoguanidine improved renal function and attenuated arsenic led renal oxidative stress, fibrosis, and decreased the kidney injury score. Additionally, arsenite-intoxication resulted in significant rise in hepatic parameters (serum aspartate aminotransferase, alanine transferase, alkaline phosphatase, and bilirubin (p < 0.001) along with multi-fold increase in oxidative stress, fibrosis and liver injury score in rats, which was significantly (p < 0.001) attenuated by concurrent administration of iNOS inhibitors). Hence, it is concluded that iNOS inhibitors attenuate sodium arsenite-induced renal and hepatic dysfunction in rats.

Curcumin, Alone or in Combination with Aminoguanidine, Increases Antioxidant Defenses and Glycation Product Detoxification in Streptozotocin-Diabetic Rats: A Therapeutic Strategy to Mitigate Glycoxidative Stress

Both oxidative stress and the exacerbated generation of advanced glycation end products (AGEs) have crucial roles in the onset and progression of diabetic complications. Curcumin has antioxidant and antidiabetic properties; its combination with compounds capable of preventing the advanced glycation events, such as aminoguanidine, is an interesting therapeutic option to counteract diabetic complications. This study is aimed at investigating the effects of treatments with curcumin or aminoguanidine, alone or in combination, on metabolic alterations in streptozotocin-diabetic rats; the focus was mainly on the potential of these bioactive compounds to oppose the glycoxidative stress. Curcumin (90 mg/kg) or aminoguanidine (50 and 100 mg/kg), alone or in combination, slightly decreased glycemia and the biomarkers of early protein glycation, but markedly decreased AGE levels (biomarkers of advanced glycation) and oxidative damage biomarkers in the plasma, liver, and kidney of diabetic rats. Some novel insights about the in vivo effects of these bioactive compounds are centered on the triggering of cytoprotective machinery. The treatments with curcumin and/or aminoguanidine increased the activities of the antioxidant enzymes (paraoxonase 1, superoxide dismutase, and catalase) and the levels of AGE detoxification system components (AGE-R1 receptor and glyoxalase 1). In addition, combination therapy between curcumin and aminoguanidine effectively prevented dyslipidemia in diabetic rats. These findings demonstrate the combination of curcumin (natural antioxidant) and aminoguanidine (prototype therapeutic agent with anti-AGE activity) as a potential complementary therapeutic option for use with antihyperglycemic agents, which may aggregate beneficial effects against diabetic complications.

Ameliorative effect of nerolidol on cyclophosphamide-induced gonadal toxicity in Swiss Albino mice: Biochemical-, histological- and immunohistochemical-based evidences

Cyclophosphamide (CP) is commonly used as antineoplastic and immunosuppressant drug with noticeable gonadotoxic profile. Nerolidol (NER) is a sesquiterpene with potent antioxidant and anti-inflammatory properties. Thus, the present study was designed to explore its possible gonadal protective potential against cyclophosphamide-induced testicular, epididymal, seminal and spermatozoal toxicities. Animals were divided into five groups: control (normal saline for 14 days), treatment group (NER 200 and 400 mg/kg, p.o) for 14 days along with a single dose of cyclophosphamide (200 mg/kg, i.p) on 7^th day, toxic and Per se groups (cyclophosphamide 200 mg/kg i.p) on 7^th day and NER 400 mg/kg for 14 days respectively. Animals were sacrificed on the 15 day, and body weight, weight of reproductive organs, testosterone level, sperm count, biochemical parameters, histopathological and immunohistochemical studies were performed in the testes, epididymis and in the serum. CP administration induced oxidative stress, nitrative stress, inflammation, reduced testosterone level, sperm count, increased expression of MPO and caused histological aberrations in the testes, epididymis and seminal vesicles. CP caused reduced sperm count, sperm motility and testosterone level which got reversed upon treatment with nerolidol in a dose-dependent manner. Nerolidol thus acted as a gonadoprotective molecule and prevented the gonadotoxicity of CP.

Effect of Captopril on Brain Oxidative Damage in Pentylenetetrazole-Induced Seizures in Mice

Background: Frequent seizure is followed by overproduction of free radicals and brain oxidative stress. Renin angiotensin system (RAS) has some effects on central nervous system. We designed this research to challenge the effect of captopril as an angiotensin converting enzyme (ACE) inhibitor against brain oxidative stress in pentylenetetrazole (PTZ) -induced seizures in mice. Methods: The groups were including (1) Control (saline); (2) PTZ (100 mg/kg, i.p.), (3-5) PTZ- captopril (Capto) that received three doses of Capto 10, 50 and 100 mg/kg 30 min before PTZ injection. Latency time in the onset minimal clonic seizures (MCS) and generalized tonic-clonic seizures (GTCS) were recorded. The level of malondialdehyde (MDA) and total thiol, as well as superoxide dismutase (SOD) and catalase (CAT) activity in the hippocampus and cortex were measured. Results: All doses of captopril postponed the onset of MCS and GTCS. Accumulation of MDA in the brain tissues of PTZ group was higher than control group, while total thiol content and CAT activity were lower. Pretreatment with captopril (100 mg/kg) diminished MDA concentration compared with PTZ group. Captopril (50 and 100 mg/kg) also increased the level of total thiol groups versus PTZ group. Captopril injection (50 and 100 mg/kg) elevated the activity of SOD and CAT in the brain tissues. In addition captopril administration diminished mortality rate caused by PTZ. Conclusion: Findings demonstrated that convulsions caused by PTZ were followed by oxidative stress status in the brain tissues. Pretreatment with captopril attenuated the effect of PTZ on brain tissue oxidative damage.<br />

Aminoguanidine affects systemic and lung inflammation induced by lipopolysaccharide in rats

BACKGROUND

Nitric oxide is a mediator of potential importance in numerous physiological and inflammatory processes in the lung. Aminoguanidine (AG) has been shown to have anti-inflammation and radical scavenging properties. This study aimed to investigate the effects of AG, an iNOS inhibitor, on lipopolysaccharide (LPS)-induced systemic and lung inflammation in rats.

METHODS

Male Wistar rats were divided into control, LPS (1 mg/kg/day i.p.), and LPS groups treated with AG 50, 100 or 150 mg/kg/day i.p. for five weeks. Total nitrite concentration, total and differential white blood cells (WBC) count, oxidative stress markers, and the levels of IL-4, IFN-γ, TGF-β1, and PGE2 were assessed in the serum or bronchoalveolar lavage fluid (BALF).

RESULTS

Administration of LPS decreased IL-4 level (p < 0.01) in BALF, total thiol content, superoxide dismutase (SOD) and catalase (CAT) activities (p < 0.001) in BALF and serum, and increased total nitrite, malondialdehyde (MDA), IFN-γ, TGF-β1 and PGE2 (p < 0.001) concentrations in BALF. Pre-treatment with AG increased BALF level of IL-4 and total thiol as well as SOD and CAT activities (p < 0.05 to p < 0.001), but decreased BALF levels of total nitrite, MDA, IFN-γ, TGF-β1, and PGE2 (p < 0.01 to p < 0.001). AG treatment decreased total WBC count, lymphocytes and macrophages in BALF (p < 0.01 to p < 0.001) and improved lung pathological changes including interstitial inflammation and lymphoid infiltration (p < 0.05 to p < 0.001).

CONCLUSIONS

AG treatment reduced oxidant markers, inflammatory cytokines and lung pathological changes but increased antioxidants and anti-inflammatory cytokines. Therefore, AG may play a significant protective role against inflammation and oxidative stress that cause lung injury.