In vivo evaluation of the protective effects of arjunolic acid against lipopolysaccharide-induced septic myocardial injury

Sepsis-induced cardiomyopathy: understanding pathophysiology and clinical implications

Sepsis is a life-threatening form of organ dysfunction resulting from a dysregulated response to infection. The complex pathogenesis of sepsis poses challenges because of the lack of reliable biomarkers for early identification and effective treatments. As sepsis progresses to severe forms, cardiac dysfunction becomes a major concern, often manifesting as ventricular dilation, a reduced ejection fraction, and a diminished contractile capacity, known as sepsis-induced cardiomyopathy (SIC). The absence of standardized diagnostic and treatment protocols for SIC leads to varied criteria being used across medical institutions and studies, resulting in significant outcome disparities. Despite the high prevalence of SIC, accurate statistical data are lacking. To understand how SIC affects sepsis prognosis, a thorough exploration of its pathophysiological mechanisms, including systemic factors and complex signalling within myocardial and immune cells, is required. Identifying the factors influencing SIC occurrence and progression is crucial and must be conducted within specific clinical contexts. In this review, the clinical manifestations, pathophysiological mechanisms, and treatment strategies for SIC are discussed, along with the clinical background. We aim to connect current practices with future research challenges, providing clear guidance for clinicians and researchers.

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.

PTX3 mediates PI3K/AKT/mTOR signaling to downregulate apoptosis and autophagy to attenuate myocardial injury in sepsis

Background

This study aimed to investigate the effect and mechanism of Pentraxin 3 (PTX3) on myocardial injury in sepsis.

Methods

Thirty male C57BL/6 mice were randomly assigned to Groups A, B, or C. Mice in Groups A and B were injected with unloaded lentivirus, while mice in Group C were injected with lentivirus encoding PTX3 overexpression. Seven days after injection, septic myocardial injury mouse models were constructed following intraperitoneal injection with LPS in Groups B and C, and mice in Group A were intraperitoneally injected with normal saline. Cardiac function was examined using echocardiography; pathological variation of myocardial cells was measured through HE staining, transmission electron microscopy, and TUNEL staining; and Western blot was used to measure the expression of PI3K/AKT/mTOR pathway-related, autophagy-related, and apoptosis-related proteins in mice myocardial cells.

Results

PTX3 significantly improved cardiac function and structure in sepsis-stricken mice, and PTX3 alleviated cardiac damage caused by sepsis. PTX3 reduced the relative protein expression of p-PI3K, p-AKT, mTOR, LC3I/II, Beclin, ATG5, Bax, Caspase-3, and Caspase-9 in septic mouse cardiomyocytes and increased the relative protein expression of Bcl-2.

Conclusion

PTX3 can attenuate myocardial injury in sepsis due to the down-regulation of apoptosis and autophagy induced by the PI3K/AKT/mTOR pathway.

Arjunolic acid protects the intestinal epithelial barrier, ameliorating Crohn's disease-like colitis by restoring gut microbiota composition and inactivating TLR4 signalling

BACKGROUND AND AIMS

Crohn's disease (CD) is characterized by an overabundance of epithelial cell death and an imbalance in microflora, both of which contribute to the dysfunction of the intestinal barrier. Arjunolic acid (AA) has anti-apoptotic effects and regulates microbiota efficacy. The objective of this study was to assess the impact of the treatment on colitis resembling Crohn's disease, along with exploring the potential underlying mechanism.

METHODS

CD animal models were created using Il-10-/- mice, and the impact of AA on colitis in mice was evaluated through disease activity index, weight fluctuations, pathological examination, and assessment of intestinal barrier function. To clarify the direct role of AA on intestinal epithelial cell apoptosis, organoids were induced by LPS, and TUNEL staining was performed. To investigate the potential mechanisms of AA in protecting the intestinal barrier, various methods including bioinformatics analysis and FMT experiments were employed.

RESULTS

The treatment for AA enhanced the condition of colitis and the function of the intestinal barrier in Il-10-/- mice. This was demonstrated by the amelioration of weight loss, reduction in tissue inflammation score, and improvement in intestinal permeability. Moreover, AA suppressed the apoptosis of intestinal epithelial cells in Il-10-/- mice and LPS-induced colon organoids, while also reducing the levels of Bax and C-caspase-3. In terms of mechanism, AA suppressed the activation of TLR4 signaling in Il-10-/- mice and colon organoids induced by LPS. In addition, AA increased the abundance of short-chain fatty acid-producing bacteria in the stool of Il-10-/- mice, and transplantation of feces from AA-treated mice improved CD-like colitis.

CONCLUSIONS

The results of our study demonstrate that AA has a protective effect on the intestinal barrier in Crohn's disease-like colitis by preventing apoptosis. Additionally, this groundbreaking study reveals the capacity of AA to hinder TLR4 signaling and alter the makeup of the intestinal microbiome. The findings present fresh possibilities for treating individuals diagnosed with Crohn's disease. AA offers a hopeful novel strategy for managing Crohn's disease by obstructing crucial pathways implicated in intestinal inflammation and enhancing the gut microbiota.

Cardioprotective effects of arjunolic acid in LPS-stimulated H9C2 and C2C12 myotubes via the My88-dependent TLR4 signaling pathway

CONTEXT

Arjunolic acid (AA) is a triterpenoid saponin found in Terminalia arjuna (Roxb.) Wight & Arn. (Combretaceae). It exerts cardiovascular protective effects as a phytomedicine. However, it is unclear how AA exerts the effects at the molecular level.

OBJECTIVE

This study investigates the cardioprotective effects of arjunolic acid (AA) via MyD88-dependant TLR4 downstream signaling marker expression.

MATERIALS AND METHODS

The MTT viability assay was used to assess the cytotoxicity of AA. LPS induced in vitro cardiovascular disease model was developed in H9C2 and C2C12 myotubes. The treatment groups were designed such as control (untreated), LPS control, positive control (LPS + pyrrolidine dithiocarbamate (PDTC)-25 µM), and treatment groups were co-treated with LPS and three concentrations of AA (50, 75, and 100 µM) for 24 h. The changes in the expression of TLR4 downstream signaling markers were evaluated through High Content Screening (HCS) and Western Blot (WB) analysis.

RESULTS

After 24 h of co-treatment, the expression of TLR4, MyD88, MAPK, JNK, and NF-κB markers were upregulated significantly (2-6 times) in the LPS-treated groups compared to the untreated control in both HCS and WB experiments. Evidently, the HCS analysis revealed that MyD88, NF-κB, p38, and JNK were significantly downregulated in the H9C2 myotube in the AA treated groups. In HCS, the expression of NF-κB was downregulated in C2C12. Additionally, TLR4 expression was downregulated in both H9C2 and C2C12 myotubes in the WB experiment.

DISCUSSION AND CONCLUSIONS

TLR4 marker expression in H9C2 and C2C12 myotubes was subsequently decreased by AA treatment, suggesting possible cardioprotective effects of AA.

DUSP1 interacts with and dephosphorylates VCP to improve mitochondrial quality control against endotoxemia-induced myocardial dysfunction

Dual specificity phosphatase 1 (DUSP1) and valosin-containing protein (VCP) have both been reported to regulate mitochondrial homeostasis. However, their impact on mitochondrial quality control (MQC) and myocardial function during LPS-induced endotoxemia remains unclear. We addressed this issue by modeling LPS-induced endotoxemia in DUSP1 transgenic (DUSP1TG) mice and in cultured DUSP1-overexpressing HL-1 cardiomyocytes. Accompanying characteristic structural and functional deficits, cardiac DUSP1 expression was significantly downregulated following endotoxemia induction in wild type mice. In contrast, markedly reduced myocardial inflammation, cardiomyocyte apoptosis, cardiac structural disorder, cardiac injury marker levels, and normalized systolic/diastolic function were observed in DUSP1TG mice. Furthermore, DUSP1 overexpression in HL-1 cells significantly attenuated LPS-mediated mitochondrial dysfunction by preserving MQC, as indicated by normalized mitochondrial dynamics, improved mitophagy, enhanced biogenesis, and attenuated mitochondrial unfolded protein response. Molecular assays showed that VCP was a substrate of DUSP1 and the interaction between DUSP1 and VCP primarily occurred on the mitochondria. Mechanistically, DUSP1 phosphatase domain promoted the physiological DUSP1/VCP interaction which prevented LPS-mediated VCP Ser784 phosphorylation. Accordingly, transfection with a phosphomimetic VCP mutant abolished the protective actions of DUSP1 on MQC and aggravated inflammation, apoptosis, and contractility/relaxation capacity in HL-1 cardiomyocytes. These findings support the involvement of the novel DUSP1/VCP/MQC pathway in the pathogenesis of endotoxemia-caused myocardial dysfunction.

Physiological Responses of Two Olive Cultivars to Salt Stress

The olive tree (Olea europaea L.) is the main fruit tree in most of the arid and semi-arid regions of Tunisia, which is where the problem of salinity is more pronounced. Salinity is one of the main factors that affects the productivity of olive trees, so the objective of this experiment was to study the effects of salinity on the photosynthesis, water relations, mineral status, and enzymatic activity of two cultivars of Olea europaea L., 'Chemlali' and 'Koroneiki'. The trial was conducted under controlled conditions in a greenhouse for a period of 49 days and included two treatments: T0 control and T100 (irrigation with 100 mM of NaCl solution). Under salinity stress, the photosynthesis, stomatal conductance, and leaves of both cultivars were negatively affected. 'Chemlali' showed greater tolerance to NaCl salinity, based on a progressive decrease in osmotic potential (Ψπ) followed by a progressive and synchronous decrease in gs, without a comparable decrease in photosynthesis. The water use efficiency (WUE) improved as a result. In addition, the K+/Na+ ratio in 'Chemlali' rose. This appears to be crucial for managing stress. Conversely, enzymatic activity showed an accumulation of glutathione peroxidase (GPX) in stressed plants. The catalase (CAT) and ascorbate peroxidase (APX) content decreased in both stressed varieties. It can be concluded that the cultivar 'Koroneiki' is more susceptible to salt stress than the cultivar 'Chemlali', because the accumulation of GPX and the decreases in CAT and APX were more pronounced in this cultivar.

The Effects of Bacterial Lipopolysaccharide (LPS) on Turkey Poults: Assessment of Biochemical Parameters and Histopathological Changes

A lipopolysaccharide (LPS) is a large molecule and an outer membrane glycolipid found in Gram-negative bacteria, including Escherichia coli (E. coli). These molecules (LPS) target acute inflammatory responses and significant physiological changes. Importantly, E. coli is considered one of the most important bacterial causes of avian colibacillosis that affect domestic turkey industry. However, little information is available about the potential influence of LPS on the biochemical parameters and histopathological changes in turkey poults. Therefore, this study aimed to evaluate the influence of bacterial lipopolysaccharide (LPS) molecules on serum biomarkers and histopathological changes in turkey poults. The birds were randomly divided into five groups, as follows: group I did not receive any inoculation; group II was inoculated with sterile saline; and groups III, IV, and V were inoculated intraperitoneally with LPS at 0.01, 0.1, and 1 mg/kg of body weight (BW), respectively. The biochemical parameters and the histopathology of different organs were examined in all birds one day post-inoculation. Our results revealed hypolipidemia, hypoglycemia, a significant decrease in uric acid, and a significant increase in serum activities of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and creatine kinase (CK), as well as cardiac troponin T concentrations in treated groups. Moreover, there was a significant increase in α1-, β-, and γ-globulin concentrations and a decrease in albumin and α2-globulin concentrations in group V. However, a significant increase in α2- and γ-globulin levels and a decrease in albumin levels were detected in groups III and IV. In addition, significant decreases in the albumin/globulin ratio were recorded in all LPS-treated groups. Hepatocellular and cardiac muscle necrosis, slight renal changes, and massive pulmonary inflammatory reactions were recorded. This study provides valuable information about serum biomarkers, protein fractions, and histopathological changes in turkey poults treated with LPS for further investigations of pathophysiological mechanisms in avian medicine along with biomedical research.