Does endurance training protect from lipotoxicity?

Scolymus hispanicus (Golden Thistle) Ameliorates Hepatic Steatosis and Metabolic Syndrome by Reducing Lipid Accumulation, Oxidative Stress, and Inflammation in Rats under Hyperfatty Diet

Background

Lipotoxicity is characterized by a metabolic disturbance leading to the development of nonalcoholic fatty liver disease (NAFLD). Some medicinal plant extracts exert hepatoprotective activity by modulating oxidative stress, inflammation, and metabolic disorders. Scolymus hispanicus or the golden thistle can be considered an important natural source of antioxidants. In traditional medicine, the consumption of this plant is recommended for diseases of the liver and intestines.

Objective

In this study, we aimed to determine the effects of Scolymus hispanicus on a hyperfatty diet- (HFD-) induced metabolic disorders, oxidative stress, and inflammation.

Materials and Methods

Our experiment focused on the administration of an HFD (40%) in Rattus norvegicus for 2 months and treatment with the aqueous extract of Scolymus hispanicus at a rate of 100 mg/kg during the last eight days of experimentation. In this context, several aspects were studied: the evaluation of blood biochemical parameters, liver function such as lipids and glycogen, markers of oxidative stress (TBARS, carbonyl proteins, advanced oxidation proteins, catalase, and SOD) and inflammation (NO and NFkB), morphological study of hepatocytes in primary culture, and histological study of the liver.

Results

Lipotoxicity induced metabolic disorders, both serum and tissue. HFD induced an increase in the total lipids and a decrease in glycogen reserve and an alteration in the oxidant-antioxidant balance. HFD induced an increase in markers of liver damage, which resulted in NAFLD, confirmed by histological study and hepatocytes cell culture. Scolymus appears to have lipid-lowering, hypoglycemic, anti-inflammatory and antioxidant properties. It improved glucose tolerance and the condition of fatty liver disease.

Conclusion

Golden thistle improves glucose tolerance and hyperlipidemia and ameliorates hepatic steatosis by reducing oxidative stress, inflammation, and lipid accumulation. Its incorporation into a dietary program or as an aliment supplement would prevent hepatic complications associated with an HFD.

Changes in circulating miRNA19a-3p precede insulin resistance programmed by intra-uterine growth retardation in mice

Objective

Individuals born with intrauterine growth retardation (IUGR) are more prone to cardio-metabolic diseases as adults, and environmental changes during the perinatal period have been identified as potentially crucial factors. We have studied in a preclinical model early-onset molecular alterations present before the development of a clinical phenotype.

Methods

We used a preclinical mouse model of induced IUGR, in which we modulated the nutrition of the pups during the suckling period, to modify their susceptibility to cardio-metabolic diseases in adulthood.

Results

Mice born with IUGR that were overfed (IUGR-O) during lactation rapidly developed obesity, hepatic steatosis and insulin resistance, by three months of age, whereas those subjected to nutrition restriction during lactation (IUGR-R) remained permanently thin and highly sensitive to insulin. Mice born with IUGR and fed normally during lactation (IUGR-N) presented an intermediate phenotype and developed insulin resistance by 12 months of age. Molecular alterations to the insulin signaling pathway with an early onset were observed in the livers of adult IUGR-N mice, nine months before the appearance of insulin resistance. The implication of epigenetic changes was revealed by ChIP sequencing, with both posttranslational H3K4me3 histone modifications and microRNAs involved.

Conclusions

These two changes lead to the coherent regulation of insulin signaling, with a decrease in Akt gene transcription associated with an increase in the translation of its inhibitor, Pten. Moreover, we found that the levels of the implicated miRNA19a-3p also decreased in the blood of young adult IUGR mice nine months before the appearance of insulin resistance, suggesting a possible role for this miRNA as an early circulating biomarker of metabolic fate of potential use for precision medicine.

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Male mice are highly sensitive to changes in nutrition during the perinatal period.

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Post-natal nutrition modulates metabolic diseases induced by IUGR in male mice.

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Metabolic programming by perinatal nutrition involves epigenetic mechanisms.

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Pre-symptomatic IUGR mice present molecular alterations of the insulin pathway.

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Plasma miRNA19a-3p levels are associated with the development of insulin resistance.

Chronic Olanzapine Treatment Induces Disorders of Plasma Fatty Acid Profile in Balb/c Mice: A Potential Mechanism for Olanzapine-Induced Insulin Resistance

Background

Atypical antipsychotics such as olanzapine cause metabolic side effects leading to obesity and insulin resistance. The underlying mechanisms remain elusive. In this study we investigated the effects of chronic treatment of olanzapine on the fatty acid composition of plasma in mice.

Methods

Twenty 8-week female Balb/c mice were randomly assigned to two groups: the OLA group and the control group. After treatment with olanzapine (10 mg/kg/day) or vehicle intraperitoneally for 8 weeks, fasting glucose, insulin levels and oral glucose tolerance test were determined. Effects on plasma fatty acid profile and plasma indices of D5 desaturase, D6 desaturase and SCD1 activity were also investigated.

Results

Chronic administration of olanzapine significantly elevated fasting glucose and insulin levels, impaired glucose tolerance, but did not increase body weight. Total saturated fatty acids and n-6 polyunsaturated fatty acids were significantly increased and total monounsaturated fatty acids were significantly decreased, while total n-3 polyunsaturated fatty acids showed no prominent changes. Chronic olanzapine treatment significantly up-regulated D6 desaturase activity while down-regulating D5 desaturase activity. Palmitic acid (C16:0), dihomo-γ-linolenic acid (C20:3n-6) and D6 desaturase were associated with an increase probability of insulin resistance, whereas nervonic acid (C24:1) and SCD1 were significantly associated with a lower insulin resistance probability.

Conclusions

All results indicated that such drug-induced effects on fatty acid profile in plasma were relevant for the metabolic adverse effects associated with olanzapine and possibly other antipsychotics. Further studies are needed to investigate geneticand other mechanisms to explain how plasma fatty acids regulate glucose metabolism and affect the risk of insulin resistance.

Differences in the serum nonesterified Fatty Acid profile of young women associated with a recent history of gestational diabetes and overweight/obesity

Background

Nonesterified fatty acids (NEFA) play pathophysiological roles in metabolic syndrome and type 2 diabetes (T2D). In this study, we analyzed the fasting NEFA profiles of normoglycemic individuals at risk for T2D (women with a recent history of gestational diabetes (GDM)) in comparison to controls (women after a normoglycemic pregnancy). We also examined the associations of NEFA species with overweight/obesity, body fat distribution and insulin sensitivity.

Subjects and Methods

Using LC-MS/MS, we analyzed 41 NEFA species in the fasting sera of 111 women (62 post-GDM, 49 controls). Clinical characterization included a five-point oral glucose tolerance test (OGTT), biomarkers and anthropometrics, magnetic resonance imaging (n = 62) and a food frequency questionnaire. Nonparametric tests with Bonferroni correction, binary logistic regression analyses and rank correlations were used for statistical analysis.

Results

Women after GDM had a lower molar percentage of total saturated fatty acids (SFA; 38.55% vs. 40.32%, p = 0.0002) than controls. At an explorative level of significance several NEFA species were associated with post-GDM status (with and without adjustment for body mass index (BMI) and HbA1c): The molar percentages of 14:0, 16:0, 18:0 and 18:4 were reduced, whereas those of 18:1, 18:2, 20:2, 24:4, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA) and total n-6 NEFA were increased. BMI and the amount of body fat correlated inversely with several SFA and MUFA and positively with various PUFA species over the whole study cohort (abs(ρ)≥0.3 for all). 14:0 was inversely and BMI-independently associated with abdominal visceral adiposity. We saw no correlations of NEFA species with insulin sensitivity and the total NEFA concentration was similar in the post-GDM and the control group.

Conclusion

In conclusion, we found alterations in the fasting NEFA profile associated with a recent history of gestational diabetes, a risk marker for T2D. NEFA composition also varied with overweight/obesity and with body fat distribution, but not with insulin sensitivity.