High-fat diet increases mortality and intensifies immunometabolic changes in septic mice

A high-lipid diet leads to greater pathology and lower tolerance during infection

Altered food landscapes contribute importantly to wildlife disease dynamics and may play a critical role in host heterogeneity in disease outcomes through changes in host diet composition. We explored the effects of dietary macronutrient composition on disease pathology and feeding behavior of canaries (Serinus canaria domestica) infected with Mycoplasma gallisepticum (MG). In the first experiment, we provided canaries with isocaloric diets composed of identical ingredients that varied in macronutrient content (high protein or high lipid) then MG- or sham-inoculated birds. In the second experiment, we offered both diets to canaries before and after MG or sham inoculation. In experiment one, high-protein diet birds consumed more food than high-lipid diet birds and experienced a more pronounced decrease in food intake after infection. High-protein diet birds were more tolerant to MG infection, exhibiting reduced pathology when compared with high-lipid diet birds, despite the two treatments having similar levels of MG-specific antibodies and MG loads. When birds had access to both diets, they consumed more of the high-protein diet and experienced pathology for less time than lipid- or protein-restricted birds. These results highlight that macronutrient makeup of the diet can shape vertebrate host tolerance and pathology, which has direct implications for host-pathogen transmission dynamics.

Piperine as an Herbal Alternative for the Prevention of Drug-Induced Liver Damage Caused by Paracetamol

Background/Objective: Hepatic drug intoxication is becoming increasingly common with the increasing use of chronic medications. Piperine has emerged as a promising alternative for protecting the liver against drug-induced injury. We evaluated the prophylactic effects of piperine in C57BL/6 mice with an acute liver injury induced by a paracetamol (APAP) overdose. Methods: Piperine was administered at a dose of 20 mg/kg (P20) or 40 mg/kg (P40) for eight consecutive days before the animals were exposed to a hepatotoxic dose of paracetamol (500 mg/kg). The animals were euthanized 3 h after the paracetamol overdose. Results: The prophylactic treatment with piperine (P20 and P40) maintained the levels of alanine aminotransferase (ALT) and the biomarkers of oxidative damage (TBARS and carbonylated proteins), which were statistically similar to those for the control group. The extent of hepatocyte necrosis and TNF-α (tumor necrosis factor-alpha) levels were lower than those in the group exposed to liver injury (APAP group). Piperine modulated the gene expression of CYP2E1 (cytochrome P4502E1) and the inflammasome pathway (NLRP3, CASP-1, IL-1β, and IL-18), which play a crucial role in the inflammatory response. In the P40 group, the degree of hepatic hyperemia was similar to that in the control group, as was the increase in metalloproteinase 9 (MMP-9) activity. Conclusion: Piperine has demonstrated beneficial and promising effects for the prevention of liver injury resulting from paracetamol-induced drug intoxication.

Metabolic consequences of interesterified palm oil and PCB-126 co-exposure in C57BL/6 mice

Metabolic dysfunction-associated steatotic liver disease (MASLD) is defined as morphofunctional changes in the liver. Studies have shown that Westernized eating patterns and environmental pollutants can directly induce the development of MASLD. This study evaluates the effect of co-exposure to interesterified palm oil (IPO) and 3,3',4,4',5-pentachlorobiphenyl (PCB-126) on the progression of MASLD in an animal model. C57BL/6 mice were fed IPO and co-exposed to PCB-126 for ten weeks. The co-exposure led to an imbalance in carbohydrate metabolism, increased systemic inflammation markers, and morphofunctional changes in the liver. These liver changes included the presence of inflammatory cells, fibrosis, alterations in aspartate transaminase (AST) and alanine transaminase (ALT) enzymes, and imbalance in gene expression related to fatty acid β-oxidation, de novo lipogenesis, mitochondrial dynamics, and endoplasmic reticulum stress. Separate exposures to IPO and PCB-126 affected metabolism and MASLD progression. Nutritional and lifestyle factors may potentiate the onset and severity of MASLD.

Sepsis and obesity: a scoping review of diet-induced obesity murine models

BACKGROUND

Sepsis, the life-threatening host response to infection, is a major cause of mortality. Obesity increases vulnerability to sepsis; however, some degree of obesity may be protective, called the "obesity paradox". This scoping review systematically maps the literature on outcomes associated with diet-induced obesity and sepsis-induced organ injury, focusing on non-transgenic murine models.

METHODS

A literature search of primary articles was conducted from database inception to June 2023. Eligible articles compared diet-induced obesity to non-obese mice in sepsis models involving live pathogens. Two reviewers screened articles and extracted data on obesogenic and sepsis models utilized, and organ injury outcomes, including physiological dysfunction, histological alterations, and biochemical changes.

RESULTS

Seventeen studies met eligibility criteria; 82% used male C57BL/6 mice, and 88% used cecal ligation and puncture to induce sepsis. Most studies used 60% high-fat diets compared to 10-16% fat in controls. Seven (64%) studies reported increased mortality in obese septic mice, one (9%) observed a decrease, and three (37%) found no significant difference. The liver, lungs, and kidneys were the most studied organs. Alanine transaminase results were inconclusive. Myeloperoxidase levels were increased in the livers of two studies and inconclusive in the lungs of obese septic mice. Creatinine and neutrophil gelatinase-associated lipocalin were elevated in obese septic mice.

CONCLUSIONS

There is variability in the methodology and measured outcomes in murine models of diet-induced obesity and sepsis and a lack of studies in female mice. The absence of standardized models has produced conflicting findings on the impact of obesity on sepsis outcomes.

Potential of piperine for neuroprotection in sepsis-associated encephalopathy

AIMS

Sepsis-associated encephalopathy (SAE) is a common complication that increases mortality and leads to long-term cognitive impairment in sepsis survivors. However, no specific or effective therapy has been identified for this complication. Piperine is an alkaloid known for its anti-inflammatory, antioxidant, and neuroprotective properties, which are important characteristics for treatment of SAE. The objective of this study was to evaluate the neuroprotective effect of piperine on SAE in C57BL/6 mice that underwent cecum ligation and perforation surgery (CLP).

MAIN METHODS

C57BL/6 male mice were randomly assigned to groups that underwent SHAM surgery or CLP. Mice in the CLP group were treated with piperine at doses of 20 or 40 mg/kg for short- (5 days) or long-term (10 days) periods after CLP.

KEY FINDINGS

Our results revealed that untreated septic animals exhibited increased concentrations of IL-6, TNF, VEGF, MMP-9, TBARS, and NLRP3, and decreased levels of BDNF, sulfhydryl groups, and catalase in the short term. Additionally, the levels of carbonylated proteins and degenerated neuronal cells were increased at both time points. Furthermore, short-term and visuospatial memories were impaired. Piperine treatment reduced MMP-9 activity in the short term and decreased the levels of carbonylated proteins and degenerated neuronal cells in the long term. It also lowered IL-6 and TBARS levels at both time points evaluated. Moreover, piperine increased short-term catalase and long-term BDNF factor levels and improved memory at both time points.

SIGNIFICANCE

In conclusion, our data demonstrate that piperine exerts a neuroprotective effect on SAE in animals that have undergone CLP.