Association Between Aerobic Exercise and Rosiglitazone Avoided the NAFLD and Liver Inflammation Exacerbated in PPAR-α Knockout Mice

Effects of swimming exercise combined with silymarin and vitamin C supplementation on hepatic inflammation, oxidative stress, and histopathology in elderly rats with high-fat diet-induced liver damage

OBJECTIVES

The aim of this study was to demonstrate that swimming exercise combined with silymarin and vitamin C supplementation improves hepatic inflammation, oxidative stress, and liver histopathology in elderly rats with high-fat diet-induced liver damage.

METHODS

Forty elderly male Wistar rats were randomly assigned to five groups (n = 8 in each): a normal diet (control), a high-fat diet (HFD), HFD + silymarin and vitamin C supplementation (HFD+Sup), HFD + swimming exercise (HFD+Exe), and HFD+Sup+Exe group (HFD+Sup+Exe). The non-alcoholic fatty liver model was induced for 6 wk in the HFD groups. After 6 wk of consuming an HFD, a daily supplemental gavage was administered to rats as an intervention along with HFD in the supplement groups for 8 wk. Moreover, rats in the exercise groups were subjected to swimming exercise training 5 d/wk for the same period.

RESULTS

The combination of swimming training and supplementation caused significant decreases in liver inflammatory biomarkers tumor necrosis factor-α and interleukin-1β while increasing total antioxidant capacity and peroxisome proliferator-activated receptor α (P < 0.05).

CONCLUSION

In elderly rats with liver injury caused by an HFD, the combination of exercise and silymarin with vitamin C supplementation effectively reduced oxidative stress, liver inflammation, fat accumulation, and regulated liver enzymes.

Exercise Is Medicine for Nonalcoholic Fatty Liver Disease: Exploration of Putative Mechanisms

Exercise remains a key component of nonalcoholic fatty liver disease (NAFLD) treatment. The mechanisms that underpin improvements in NAFLD remain the focus of much exploration in our attempt to better understand how exercise benefits patients with NAFLD. In this review, we summarize the available scientific literature in terms of mechanistic studies which explore the role of exercise training in modulating fatty acid metabolism, reducing hepatic inflammation, and improving liver fibrosis. This review highlights that beyond simple energy expenditure, the activation of key receptors and pathways may influence the degree of NAFLD-related improvements with some pathways being sensitive to exercise type, intensity, and volume. Importantly, each therapeutic target of exercise training in this review is also the focus of previous or ongoing drug development studies in patients with nonalcoholic steatohepatitis (NASH), and even when a regulatory-agency-approved drug comes to market, exercise will likely remain an integral component in the clinical management of patients with NAFLD and NASH.

Association between Regional Body Muscle Mass and Non-Alcoholic Fatty Liver Disease: An Observational Study Using Data from the REACTION Study

Background and aims: Regional muscle distribution is associated with abdominal obesity and metabolic syndrome. However, the relationship between muscle distribution and nonalcoholic fatty liver disease (NAFLD) remains unclear. This study was to determine the relationship between regional muscle distribution and the risk and severity of NAFLD. Methods: This cross-sectional study ultimately included 3161 participants. NAFLD diagnosed by ultrasonography was classified into three groups (non, mild, and moderate/severe). We estimated the regional body muscle mass (lower limbs, upper limbs, extremities, and trunk) through multifrequency bioelectrical impedance analysis (BIA). The relative muscle mass was defined as the muscle mass adjusted for the body mass index (BMI). Results: NAFLD participants accounted for 29.9% (945) of the study's population. Individuals with a higher lower limb, extremity, and trunk muscle mass had a lower risk of NAFLD (p < 0.001). Patients with moderate/severe NAFLD had a lower muscle mass of the lower limbs and trunk than patients with mild NAFLD (p < 0.001), while the muscle mass of the upper limbs and extremities did not differ significantly between the two groups. Moreover, similar results were found for both sexes and among different age groups. Conclusions: A higher muscle mass of the lower limbs, extremities, and trunk was negatively associated with the risk of NAFLD. A lower muscle mass of the limbs and trunk was inversely associated with the severity of NAFLD. This study provides a new theoretical basis for the development of individualized exercise prescriptions for the prevention of NAFLD in non-NAFLD patients.

Physical exercise regulates apoptosis and prostatic inflammatory effects induced by high-fat diet in PPAR-alpha deleted mice

The high-fat diet (HFD) promotes obesity and develops inflammation, causing dysregulation of energy metabolism and prostatic neoplastic tissue changes. PPARɑ deletion leads to loss of homeostasis between the pro and anti-inflammatory response, and dysregulation of lipid metabolism, causing changes in different physiological processes and damage to the prostate. On the other hand, aerobic physical exercise has been suggested as a non-pharmacological tool to improve energy metabolism and cellular metabolism in the prostate, however, the underlying molecular mechanism remains unclear. the current study aimed to evaluate PPARα as a possible regulator of the protective effects of aerobic physical exercise in the prostate by examining prostatic alterations in wild-type and PPARα deletion mice fed a standard diet or an HFD. Wild-type and PPARα-null mice were fed a standard or HFD diet for 12 weeks, and submitted to aerobic physical exercise for 8 weeks. The HFD promoted the increase of inflammatory markers IL-6, TNF-α, NF-kB, and an increase of inflammatory foci in animals in both genotypes. Although the PPARα deletion animals submitted to the aerobic physical exercise were not able to regulate response pro-inflammatory, but promoted an increase in IL-10 in the prostate. In animals WT, the aerobic physical exercise, reduced all inflammatory markers, improve the inflammatory response, and showed a higher expression of BAX and IL-10 proteins was protective against prostatic tissue lesions. Suggested that PPARα deletion associated with HFD suppressed apoptosis and increased damage prostate. On other hand, aerobic physical exercise improves prostatic tissue by increasing the response to anti-inflammatory and apoptosis protein.

Exploring Anti-Nonalcoholic Fatty Liver Disease Mechanism of Gardeniae Fructus by Network Pharmacology, Molecular Docking, and Experiment Validation

Gardeniae fructus (GF), the fruit from Gardenia jasminoides Ellis, is a traditional Chinese medicine used for the treatment of nonalcoholic fatty liver disease (NAFLD) in the clinic. To explore the hepatoprotective mechanism of GF for the treatment of NAFLD, we proposed a novel strategy that integrated in vivo efficacy evaluation, network pharmacology analysis, molecular docking, and experimental validation. A NAFLD animal model induced by high fat diet (HFD) feed was established, then orally administrated with or without GF. The results showed that GF significantly decreased the levels of serum total cholesterol (TC), lipoprotein cholesterol, triglyceride (TG), alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, free fatty acids, glucose, and insulin and the levels of liver TG, TC, and malondialdehyde compared with the nontreated HFD group. Network pharmacology studies showed that quercetin, oleanolic acid, kaempferol, and geniposide were the main biocompounds in GF that targeted the PPARα and PPARγ genes through regulating the PPAR and AMPK signal pathways to protect against NAFLD. The interactions between bioactive compounds and their corresponding target proteins were analyzed by molecular docking and subsequently confirmed using the qRT-PCR assay. Collectively, GF was a therapeutic drug for the treatment of NAFLD.

PPARα: A potential therapeutic target of cholestasis

The accumulation of bile acids in the liver leads to the development of cholestasis and hepatocyte injury. Nuclear receptors control the synthesis and transport of bile acids in the liver. Among them, the farnesoid X receptor (FXR) is the most common receptor studied in treating cholestasis. The activation of this receptor can reduce the amount of bile acid synthesis and decrease the bile acid content in the liver, alleviating cholestasis. Ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) have a FXR excitatory effect, but the unresponsiveness of some patients and the side effect of pruritus seriously affect the results of UDCA or OCA treatment. The activator of peroxisome proliferator-activated receptor alpha (PPARα) has emerged as a new target for controlling the synthesis and transport of bile acids during cholestasis. Moreover, the anti-inflammatory effect of PPARα can effectively reduce cholestatic liver injury, thereby improving patients’ physiological status. Here, we will focus on the function of PPARα and its involvement in the regulation of bile acid transport and metabolism. In addition, the anti-inflammatory effects of PPARα will be discussed in some detail. Finally, we will discuss the application of PPARα agonists for cholestatic liver disorders.

The advantages of physical exercise as a preventive strategy against NAFLD in postmenopausal women

BACKGROUND

The prevalence and severity of nonalcoholic fatty liver disease (NAFLD) increase in women after menopause. This narrative review discusses the causes and consequences of NAFLD in postmenopausal women and describes how physical activity can contribute to its prevention.

METHODS

The authors followed the narrative review method to perform a critical and objective analysis of the current knowledge on the topic. The Medical Subject Heading keywords 'physical exercise', 'menopause', 'hormone replacement therapy', 'estradiol' and 'NAFLD' were used to establish a conceptual framework. The databases used to collect relevant references included Medline and specialized high-impact journals.

RESULTS

Higher visceral adiposity, higher rate of lipolysis in adipose tissue after oestrogen drop and changes in the expression of housekeeping proteins involved in hepatic lipid management are observed in women after menopause, contributing to NAFLD. Excessive liver steatosis leads to hepatic insulin resistance, oxidative stress and inflammation, accelerating NAFLD progression. Physical activity brings beneficial effects against several postmenopausal-associated complications, including NAFLD progression. Aerobic and resistance exercises partially counteract alterations induced by metabolic syndrome in sedentary postmenopausal women, impacting NAFLD progression and severity.

CONCLUSIONS

With the increased global obesity epidemic in developing countries, NAFLD is becoming a severe problem with increased prevalence in women after menopause. Evidence shows that physical activity may delay NAFLD development and severity in postmenopausal women, although the prescription of age-appropriate physical activity programmes is advisable to assure the health benefits.

Mechanisms Mediating the Regulation of Peroxisomal Fatty Acid Beta-Oxidation by PPARα

In mammalian cells, two cellular organelles, mitochondria and peroxisomes, share the ability to degrade fatty acid chains. Although each organelle harbors its own fatty acid β-oxidation pathway, a distinct mitochondrial system feeds the oxidative phosphorylation pathway for ATP synthesis. At the same time, the peroxisomal β-oxidation pathway participates in cellular thermogenesis. A scientific milestone in 1965 helped discover the hepatomegaly effect in rat liver by clofibrate, subsequently identified as a peroxisome proliferator in rodents and an activator of the peroxisomal fatty acid β-oxidation pathway. These peroxisome proliferators were later identified as activating ligands of Peroxisome Proliferator-Activated Receptor α (PPARα), cloned in 1990. The ligand-activated heterodimer PPARα/RXRα recognizes a DNA sequence, called PPRE (Peroxisome Proliferator Response Element), corresponding to two half-consensus hexanucleotide motifs, AGGTCA, separated by one nucleotide. Accordingly, the assembled complex containing PPRE/PPARα/RXRα/ligands/Coregulators controls the expression of the genes involved in liver peroxisomal fatty acid β-oxidation. This review mobilizes a considerable number of findings that discuss miscellaneous axes, covering the detailed expression pattern of PPARα in species and tissues, the lessons from several PPARα KO mouse models and the modulation of PPARα function by dietary micronutrients.

Preparation of the peroxisome proliferator-activated receptor α polyclonal antibody: Its application in fatty liver hemorrhagic syndrome

Peroxisome proliferator-activated receptor α (PPARα) play a key role in the regulation of metabolic homeostasis, inflammation, cellular growth, and differentiation. To further explore the potential role of PPARα in the energy homeostasis of fatty liver hemorrhagic syndrome (FLHS), we reported the prokaryotic expression and purification of chicken PPARα subunit protein, and successfully prepared a polyclonal antibody against PPARα recombinant protein. The 987 bp PPARα subunit genes were cloned into the pEASY-T3 clone vector. Then the plasmid PCR products encoding 329 amino acids were ligated to pEASY-Blunt E2 vector and transformed into BL21 to induce expression. The recombinant PPARα subunit protein, containing His-tag, was purified by affinity column chromatography using Ni-NTA affinity column. Rabbit antiserum was generated by using the concentration of recombinant PPARα subunit protein as the antigen. The results of western blotting showed that the antiserum can specifically recognize chicken endogenous PPARα protein. Immunohistochemistry and immunofluorescence showed that the PPARα mainly existed in the nucleus of hepatocytes, renal epithelial cells and hypothalamic endocrine nerve cells. More importantly, western blotting and real-time quantitative PCR indicated that FLHS significantly decreased the expression of PPARα.

The effects of S-nitrosylation-induced PPARγ/SFRP5 pathway inhibition on the conversion of non-alcoholic fatty liver to non-alcoholic steatohepatitis

Background

Peroxisome proliferators-activated receptors γ (PPARγ) and secreted frizzled related protein 5 (SFRP5) are abnormally expressed in liver cells. But their role in the transformation of non-alcoholic fatty liver (NAFL) to non-alcoholic steatohepatitis (NASH) remains to be studied. We aimed to explore the role of S-nitrosylation (SNO) in the conversion of NAFL to NASH via the peroxisome PPARγ/SFRP5 pathway.

Methods

A normal diet and methionine-choline deficient diet were used to construct the NAFL and NASH mouse models, respectively. The differences between the SNO of PPARγ in both models were measured by irreversible biotinylation. Quantitative reverse transcription PCR (qRT-PCR) and Western blotting were used to detect the effect of SNO on the expression of PPARγ messageRNA (mRNA) and protein in L02 hepatocytes. Nubiscan software, luciferase reporter gene, and chromatin immunoprecipitation assay (CHIP) were used to verify the targeting relationship between PPAR and SFRP5. The expression of tumor necrosis factor α (TNFα), interleukin-1β (IL-1β), and interleukin-6 (IL-6), which are indicators for the activation of Kupffer cells, were determined by enzyme linked immunosorbent assay (ELISA) after co-cultivation of L02 hepatocytes and Kupffer macrophages, as well as the exogenous regulation of SNO, PPARγ, and SFRP5 in hepatic L02 cells.

Results

The NAFL and NASH mouse models were successfully constructed, and the level of PPARγ SNO in the NAFL model was significantly lower than the NASH model (P<0.05). The level of PPARγ was significantly downregulated after increasing the SNO of L02 cells, respectively (P<0.05). Nubiscan software and CHIP confirmed that PPARγ could bind to the promoter region of SFRP5 (P<0.05). Overexpression of PPARγ and SFRP5 could significantly downregulate the expression of TNFα, IL-1β, and IL-6 (P<0.05) correspondingly, while increasing the SNO level of L02 cells could restore the expression levels of TNFα, IL-1β, and IL-6.

Conclusions

SNO promoted the activation of macrophage Kupffer cells by inhibiting the PPARγ/SFRP5 pathway in L02 hepatocytes, thereby promoting the conversion of NAFL into NASH.

Effects of Long-Term DHA Supplementation and Physical Exercise on Non-Alcoholic Fatty Liver Development in Obese Aged Female Mice

Obesity and aging are associated to non-alcoholic fatty liver disease (NAFLD) development. Here, we investigate whether long-term feeding with a docosahexaenoic acid (DHA)-enriched diet and aerobic exercise, alone or in combination, are effective in ameliorating NAFLD in aged obese mice. Two-month-old female C57BL/6J mice received control or high fat diet (HFD) for 4 months. Then, the diet-induced obese (DIO) mice were distributed into four groups: DIO, DIO + DHA (15% dietary lipids replaced by a DHA-rich concentrate), DIO + EX (treadmill running), and DIO + DHA + EX up to 18 months. The DHA-rich diet reduced liver steatosis in DIO mice, decreasing lipogenic genes (Dgat2, Scd1, Srebp1c), and upregulated lipid catabolism genes (Hsl/Acox) expression. A similar pattern was observed in the DIO + EX group. The combination of DHA + exercise potentiated an increase in Cpt1a and Ppara genes, and AMPK activation, key regulators of fatty acid oxidation. Exercise, alone or in combination with DHA, significantly reversed the induction of proinflammatory genes (Mcp1, Il6, Tnfα, Tlr4) in DIO mice. DHA supplementation was effective in preventing the alterations induced by the HFD in endoplasmic reticulum stress-related genes (Ern1/Xbp1) and autophagy markers (LC3II/I ratio, p62, Atg7). In summary, long-term DHA supplementation and/or exercise could be helpful to delay NAFLD progression during aging in obesity.

Aerobic training improves NAFLD markers and insulin resistance through AMPK-PPAR-α signaling in obese mice

Liver steatosis is one of the main drivers for the development of whole-body insulin resistance. Conversely, aerobic training (AT) has been suggested as non-pharmacological tool to improve liver steatosis, however, the underlying molecular mechanism remains unclear. Therefore, the aim of this study was to analyze the effect of 8-weeks AT in non-alcoholic liver disease (NAFLD) outcomes in obese mice. Male C57BL/6 J wild type (WT) were fed with standard (SD) or high-fat diet (HFD) for 12-weeks. Another group fed with HFD underwent 8-weeks of AT (60% of maximum velocity), initiated at the 5th week of experimental protocol. We measured metabolic, body composition parameters, protein and gene expression inflammatory and metabolic mediators. We found that AT attenuates the weight gain, but not body fat accumulation. AT improved triacylglycerol and non-esterified fatty acid plasma concentrations, and also whole-body insulin resistance. Regarding NAFLD, AT decreased the progression of macrovesicular steatosis and inflammation through the upregulation of AMPK Thr172 phosphorylation and PPAR-α protein expression. Moreover, although no effects of intervention in PPAR-γ protein concentration were observed, we found increased levels of its target genes Cd36 and Scd1 in exercised group, demonstrating augmented transcriptional activity. AT reduced liver cytokines concentrations, such as TNF-α, IL-10, MCP-1 and IL-6, regardless of increased Ser536 NF-κB phosphorylation. In fact, none of the interventions regulated NF-κB target genes Il1b and Cccl2, demonstrating its low transcriptional activity. Therefore, we conclude that AT attenuates the progression of liver macrovesicular steatosis and inflammation through AMPK-PPAR-α signaling and PPAR-γ activation, respectively, improving insulin resistance in obese mice.

Palmitoleic acid reduces high fat diet-induced liver inflammation by promoting PPAR-γ-independent M2a polarization of myeloid cells

Palmitoleic acid (POA, 16:1n-7) is a lipokine that has potential nutraceutical use to treat non-alcoholic fatty liver disease. We tested the effects of POA supplementation (daily oral gavage, 300 mg/Kg, 15 days) on murine liver inflammation induced by a high fat diet (HFD, 59% fat, 12 weeks). In HFD-fed mice, POA supplementation reduced serum insulin and improved insulin tolerance compared with oleic acid (OA, 300 mg/Kg). The livers of POA-treated mice exhibited less steatosis and inflammation than those of OA-treated mice with lower inflammatory cytokine levels and reduced toll-like receptor 4 protein content. The anti-inflammatory effects of POA in the liver were accompanied by a reduction in liver macrophages (LM, CD11c⁺; F4/80⁺; CD86⁺), an effect that could be triggered by peroxisome proliferator activated receptor (PPAR)-γ, a lipogenic transcription factor upregulated in livers of POA-treated mice. We also used HFD-fed mice with selective deletion of PPAR-γ in myeloid cells (PPAR-γ KO^LyzCre+) to test whether the beneficial anti-inflammatory effects of POA are dependent on macrophages PPAR-γ. POA-mediated improvement of insulin tolerance was tightly dependent on myeloid PPAR-γ, while POA anti-inflammatory actions including the reduction in liver inflammatory cytokines were preserved in mice bearing myeloid cells deficient in PPAR-γ. This overlapped with increased CD206⁺ (M2a) cells and downregulation of CD86⁺ and CD11c⁺ liver macrophages. Moreover, POA supplementation increased hepatic AMPK activity and decreased expression of the fatty acid binding scavenger receptor, CD36. We conclude that POA controls liver inflammation triggered by fat accumulation through induction of M2a macrophages independently of myeloid cell PPAR-γ.

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Palmitoleic acid (POA) supplementation reduced serum insulin and improved insulin tolerance;

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Livers of POA-treated mice exhibited less steatosis and inflammation;

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POA lowered the liver M1 macrophages population and the expression of inflammation-related immune-cell markers;

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POA increased PPAR-γ, a transcription factor that regulates anti-inflammatory effects in macrophages;

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However, POA reduced liver inflammation even in mice that lack PPAR-γ expression in myeloid cells;

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POA controls liver inflammation through induction of M2a macrophages independently of PPAR-γ in myeloid cells.

Sweroside ameliorates NAFLD in high-fat diet induced obese mice through the regulation of lipid metabolism and inflammatory response

ETHNOPHARMACOLOGICAL RELEVANCE

Sweroside, an iridoid derived from Traditional Chinese Medicine, is an active component in Swertia pseudochinensis Hara. Swertia pseudochinensis Hara is first recorded in "Inner Mongolia Chinese Herb Medicine"and is considered as a folk medicine for treating hepatitis in northern China.

AIM OF THE STUDY

This study sought to elucidate the role of sweroside in high fat diet induced obesity and fatty liver by using mouse model and investigated the primary molecular mechanism via transcriptomics analysis.

MATERIALS AND METHODS

C57BL/6 mice were fed high-fat diet (HFD) for 14 weeks to induce obesity, hyperglycemia, and fatty liver. These mice were subsequently treated with HFD alone or mixed with sweroside (at a daily dosage of 60 mg per kg of BW, 120 mg per kg of BW and 240 mg per kg of BW) for 6 weeks. BW and food intake was monitored weekly. Biochemical and pathological analysis were conducted to investigate the effect of sweroside on NAFLD. RNA-sequence and RT-qPCR analysis were performed to analyze the potential mechanism.

RESULTS

The mice treated with sweroside were resistant to HFD-induced body weight gain, insulin resistance and hepatic steatosis. Ingenuity pathway analysis (IPA) demonstrated that hepatic gene networks related to lipid metabolism and inflammatory response were down-regulated in the HFD + sweroside group. PPAR-ɑ was located in the center of the hepatic gene network, and the significantly altered genes were CD36 and FGF21, which are related to hepatic inflammation and lipid metabolism. Consistently, upstream-regulators analysis revealed that the main enriched upstream-regulator was PPAR-ɑ.

CONCLUSION

Our results indicate that sweroside may ameliorate obesity with fatty liver via the regulation of lipid metabolism and inflammatory responses. The beneficial effects of sweroside might be closely associated with the regulation of PPAR-α.

Chronic exercise provides renal-protective effects with upregulation of fatty acid oxidation in the kidney of high fructose-fed rats

Excessive fructose intake causes metabolic syndrome and lipid accumulation in the kidney and leads to renal dysfunction and damage. Exercise (Ex) improves lipids regulation, but the mechanisms are unclarified in the kidney. In the present study, male Sprague-Dawley rats were allocated to groups fed with control or high-fructose (HFr) diet. Part of rats in each group underwent aerobic treadmill Ex for 12 wk. Drug treatment was performed as the fenofibrate gavage during the last 4 wk on HFr diet-fed rats. Renal function, histological changes, and expression of regulators involved in fatty acid (FA) metabolism were assessed. In CON diet-fed groups, Ex did not affect renal function or histology and significantly increased renal expression of FA β-oxidation regulators including acyl-CoA dehydrogenases (CADs), acyl-CoA oxidase, peroxisome proliferator-activated receptor (PPAR)-α, and PPAR-γ coactivator (PGC)-1α and lipogenic factors including acetyl-CoA carboxylase (ACCα), FA synthase (FAS), and sterol regulatory element-binding protein 1c. HFr caused albuminuria, lipid accumulation, and renal pathohistological changes, which were attenuated by Ex but not by fenofibrate. HFr decreased renal expression of medium- and short-chain CADs and PPAR-α and increased renal expression of ACCα, FAS, and sterol regulatory element-binding protein 1c. Ex increased expression of CADs, carnitine palmitoyltransferase type I, acyl-CoA oxidase, PPAR-α, and PGC-1α and decreased renal expression of ACCα and FAS in HFr diet-fed rats. The Ex-induced FA metabolism alteration was similar to that in the fenofibrate-treated group. In conclusion, the present study indicates that Ex enhanced renal FA metabolism, which might protect the kidney in lipid dysregulation diseases.

Alterations in the innate immune system due to exhausting exercise in intensively trained rats

It is known that intensive physical activity alters the immune system's functionality. However, the influence of the intensity and duration of exercise needs to be studied in more depth. We aimed to establish the changes in the innate immune response induced by two programmes of intensive training in rats compared to sedentary rats. A short training programme included 2 weeks of intensive training, ending with an exhaustion test (short training with exhaustion, S-TE). A second training programme comprised 5-week training including two exhaustion tests and three trainings per week. In this case, immune status was assessed before (T), immediately after (TE) and 24 h after (TE24) an additional final exhaustion test. Biomarkers such as phagocytic activity, macrophage cytokine and reactive oxygen species (ROS) production, and natural killer (NK) cell activity were quantified. S-TE was not enough to induce changes in the assessed innate immunity biomarkers. However, the second training was accompanied by a decrease in the phagocytic activity, changes in the pattern of cytokine secretion and ROS production by macrophages and reduced NK cell proportion but increased NK cytotoxic activity. In conclusion, a 5-week intense training programme, but not a shorter training, induced alterations in the innate immune system functionality.

Protective Effect of Hesperidin on the Oxidative Stress Induced by an Exhausting Exercise in Intensively Trained Rats

Intensive exercise can lead to oxidative stress, which can be particularly deleterious for lymphoid tissues. Hesperidin has demonstrated its antioxidant activity, but few studies focus on its influence on intensive training. The aim of this study was to assess the impact of hesperidin on the oxidant/antioxidant status of lymphoid tissues after an intensive training program. Wistar rats were trained for five weeks (five days per week), including two exhaustion tests plus three trainings per week. During this period, animals were orally administrated with 200 mg/kg of hesperidin or vehicle (three days per week). The oxidative status was determined before, immediately after and 24 h after an additional exhaustion test. The production of reactive oxygen species (ROS) by peritoneal macrophages, superoxide dismutase (SOD) and catalase activities in spleen, thymus and liver, and hepatic glutathione peroxidase activity (GPx) were assessed. Hesperidin prevented an increase in ROS production induced by the additional exhaustion test. Likewise, hesperidin avoided a decrease in SOD and catalase activities in the thymus and spleen that was found after the additional exhaustion test. The antioxidant effects of hesperidin were associated with a higher performance in the assessed training model. These results suggest that hesperidin, acting as an antioxidant, can prevent oxidative stress induced by exercise and improve exercise performance.

Metabolic Reprogramming by 3-Iodothyronamine (T1AM): A New Perspective to Reverse Obesity through Co-Regulation of Sirtuin 4 and 6 Expression

Obesity is a complex disease associated with environmental and genetic factors. 3-Iodothyronamine (T1AM) has revealed great potential as an effective weight loss drug. We used metabolomics and associated transcriptional gene and protein expression analysis to investigate the tissue specific metabolic reprogramming effects of subchronic T1AM treatment at two pharmacological daily doses (10 and 25 mg/kg) on targeted metabolic pathways. Multi-analytical results indicated that T1AM at 25 mg/kg can act as a novel master regulator of both glucose and lipid metabolism in mice through sirtuin-mediated pathways. In liver, we observed an increased gene and protein expression of Sirt6 (a master gene regulator of glucose) and Gck (glucose kinase) and a decreased expression of Sirt4 (a negative regulator of fatty acids oxidation (FAO)), whereas in white adipose tissue only Sirt6 was increased. Metabolomics analysis supported physiological changes at both doses with most increases in FAO, glycolysis indicators and the mitochondrial substrate, at the highest dose of T1AM. Together our results suggest that T1AM acts through sirtuin-mediated pathways to metabolically reprogram fatty acid and glucose metabolism possibly through small molecules signaling. Our novel mechanistic findings indicate that T1AM has a great potential as a drug for the treatment of obesity and possibly diabetes.

Gynostemma pentaphyllum Attenuates the Progression of Nonalcoholic Fatty Liver Disease in Mice: A Biomedical Investigation Integrated with In Silico Assay

Nonalcoholic fatty liver disease (NAFLD) is the most common type of liver disease in developed countries. Oxidative stress plays a critical role in the progression of NAFLD. Modern pharmacological study and clinical trials have demonstrated the remarkable antioxidant activity of Gynostemma pentaphyllum (GP) in chronic liver disease. One aim of this study was to explore the potential protective effects and mechanisms of action of GP extract on NAFLD. The in vivo results showed that GP extract could alleviate fatty degeneration and haptic fibrosis in NAFLD mice. For exploring the hepatoprotective mechanisms of GP, we used network pharmacology to predict the potential active components of GP and their intracellular targets in NAFLD. Based on the network pharmacology results, we further utilized biomedical assays to validate this in silico prediction. The results showed that Gypenoside XL could upregulate the protein level of PPARα in NAFLD; the transcription level of several PPARα downstream target genes such as acyl-CoA oxidase (ACO) and carnitine palmitoyltransferase-1 (CPT-1) also increased after Gypenoside XL treatment. The overexpression of ACO and CPT-1 may involve the hepatoprotective effects of GP and Gypenoside XL on NAFLD by regulating mitochondrial fatty acid β-oxidation.

Role of vitamin A oral supplementation on oxidative stress and inflammatory response in the liver of trained rats

The use of dietary supplements to enhance the benefit of exercise training is a common practice. The liver is the organ where all substances are metabolized, and certain supplements have been associated with liver injury. Vitamin A (VA), a liposoluble vitamin stored in the liver, is commonly used as an antioxidant supplement. Here, we evaluated the effect of chronic VA supplementation on oxidative damage and stress parameters in trained rats. Animals were divided into the following groups: sedentary (SE), sedentary/VA (SE+VA), exercise training (ET), and exercise training/VA (ET+VA). During 8 weeks, animals were subjected to swimming (0%, 2%, 4%, 6% body weight) for 5 days/week and a VA daily intake of 450 retinol equivalents/day. Parameters were evaluated by enzymatic activity analysis, ELISA, and Western blotting. VA caused liver lipid peroxidation and protein damage in exercised rats and inhibited the increase in HSP70 expression acquired with exercise alone. The ET group showed higher levels of antioxidant enzyme activity, and VA inhibited this adaptation. Expression of the pro-inflammatory cytokines, interleukin (IL)-1β, and tumor necrosis factor-α was reduced in the ET+VA group, while the anti-inflammatory cytokine, IL-10, was increased. Western blotting showed that both exercised groups had lower levels of the receptor for advanced glycation end products, suggesting that VA did not affect this receptor. Our study demonstrated that, although VA caused oxidative damage, a controlled administration might exert anti-inflammatory effects. Further studies with higher VA doses and longer ET interventions would elucidate more the effects of the supplementation and exercise on liver parameters.

A Biomedical Investigation of the Hepatoprotective Effect of Radix salviae miltiorrhizae and Network Pharmacology-Based Prediction of the Active Compounds and Molecular Targets

Radix salviae miltiorrhizae (Danshen in Chinese), a classic traditional Chinese medicine (TCM) herb, has been used for centuries to treat liver diseases. In this study, the preventive and curative potential of Danshen aqueous extract on acute/chronic alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) was studied. The in vivo results indicated that Danshen could alleviate hepatic inflammation, fatty degeneration, and haptic fibrogenesis in ALD and NAFLD models. In the aspect of mechanism of action, the significant reduction in MDA levels in both ALD and NAFLD models implies the decreased levels of oxidative stress by Danshen. However, Danshen treatment could not activate the internal enzymatic antioxidant system in ALD and NAFLD models. To further explore the hepatoprotective mechanism of Danshen, an in silico-based network pharmacology approach was employed in the present study. The pharmacological network analysis result revealed that six potential active ingredients such as tanshinone iia, salvianolic acid b, and Danshensu may contribute to the hepatoprotective effects of Danshen on ALD and NAFLD. The action mechanism may relate with regulating the intracellular molecular targets such as PPARα, CYP1A2, and MMP2 for regulation of lipid metabolism, antioxidant and anti-fibrogenesis by these potential active ingredients. Our studies suggest that the combination of network pharmacology strategy with in vivo experimental study may provide a forceful tool for exploring the mechanism of action of traditional Chinese medicine (TCM) herb and developing novel bioactive ingredients.