Hepatic Lipase Research Articles

Positive effects of rutin on egg quality, lipid peroxidation and metabolism in post-peak laying hens.

Excessive fat deposition due to impaired fat metabolism in chickens is a major problem in the poultry industry. Nutritional interventions are effective solutions, but current options are limited. A safe phytochemical, rutin, has shown positive effects in animals, but its effect on lipid metabolism in poultry remains unknown. Hence, this study is to investigate the effects of rutin on egg quality, serum biochemistry, fat deposition, lipid peroxidation and hepatic lipid metabolism in post-peak laying hens. A total of 360 Taihang laying hens (49-week-old) were randomly divided into five groups and fed a basal diet (control group, 0%) and a basal diet supplemented with 300 (0.03%), 600 (0.06%), 900 (0.09%), and 1,200 (0.12%) mg rutin/kg feed, respectively. The results showed that eggshell strength was significantly (p < 0.05) higher in the dietary rutin groups, whereas yolk percentage (p < 0.05), total cholesterol (TC) (p < 0.01) and yolk fat ratio (p < 0.01) decreased linearly (p < 0.05) in the dietary rutin groups. Importantly, dietary rutin reduced serum triglyceride (TG) and TC levels, decreased abdominal lipid deposition and liver index (p < 0.05), and which concomitantly decreased hepatic lipid (TG, TC, and free fatty acid) accumulation (p < 0.05). An increase (p < 0.05) in total antioxidant capacity and superoxide dismutase activity and a decrease (p < 0.05) in malondialdehyde levels were also found. At the same time, the activities of hepatic lipase, acetyl-CoA carboxylase and malic enzyme in the liver were decreased (p < 0.05). Dietary rutin also increased (p < 0.05) the expression of fatty acid oxidation-related genes (carnitine palmitoyl transferase 1, peroxisome proliferator-activated receptor α, farnesoid X receptor). Additionally, it decreased fatty acid synthesis genes (sterol regulatory element binding protein-1c, acetyl-CoA carboxylase α, stearoyl-CoA desaturase 1) (p < 0.05). In conclusion, the addition of rutin (0.06-0.12%) to the diet improved the fat metabolism and increased liver antioxidant capacity in post-peak laying hens, and these positive changes improved egg quality to some extent.

Impact of multiple different high-fat diets on metabolism, inflammatory markers, dysbiosis, and liver histology: study on NASH rat model induced diet.

The spectrum of non-alcoholic fatty liver disease (NAFLD), known as non-alcoholic steatohepatitis (NASH), can lead to advanced liver disease. It is known that a variety of diets play a significant role in the development of NAFLD/NASH. The goal of this study was to determine the most appropriate composition of diet to induce NASH in an animal model. This research used Rattus norvegicus strain Wistar (n=27), which were divided into four groups and given each diet for 12 weeks: normal diet (ND, n=7), high-fat diet (HFD, n=6), western diet (WD, n=7), and high-fat-high-fructose diet (HFHFD, n=7). Subjects were monitored for changes in body weight. Blood samples were collected for biochemical analysis, including low-density lipoprotein (LDL), triglyceride, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), hepatic lipase, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and lipopolysaccharide (LPS). Fecal samples were taken for short-chain fatty acid (SCFA) analysis. Liver histology was assessed using NAS (NAFLD activity score). A statistical comparison test was carried out using the one-way ANOVA or Kruskal-Wallis test. The highest average body weight was observed in the WD group (346.14 g). Liver enzymes, LDL, triglyceride, propionic acid, and acetic acid did not show significantly differences among the groups. TNF-α, IL-6, and hepatic lipase were significant (p = 0.000; p = 0.000; p = 0.004) and the highest level recorded in the HFD group. Butyrate acid level also showed significances (p = 0.021) with the lowest concentration seen in the HFHFD group (4.77 mMol/g). Only WD and HFHFD had a NAS ≥ 5 (14% and 14%). The highest percentage of borderline NAS was found in WD (57%). WD feeding is the most appropriate diet type to induce NASH in rats as it influences metabolic, inflammatory, dysbiosis, and liver histology of rats.

Dietary bile acids supplementation improves the growth performance and alleviates fatty liver in broilers fed a high-fat diet via improving the gut microbiota

This experiment aims to evaluate the effect of bile acids (BAs) in alleviating fatty liver disease induced by a high-fat diet (HFD) in broilers, and the modulation of the gut microbiota involved in this process. A total of 192 one-day-old Arbor Acres (AA) commercial male broilers were randomly divided into 4 groups and treated with the following diet: a basal-fat diet (BFD), a basal-fat diet plus bile acids (BFD + BAs), an HFD, and a high-fat diet plus bile acids (HFD + BAs). Bile acids were supplemented at the early growth stage (3-7 d), middle stage (17-21 d), and late stage (31-35 d). Results showed that BAs treatment had a significant effect on body weight on 14 d and 35 d, and increased the breast muscle weight and its index, but decreased the liver weight and abdominal fat weight on 35 d (P < 0.05). The supplementation of BAs significantly improved the serum lipid profile and decreased the level of triglycerides (TG), total cholesterol (TCHO), and nonesterified fatty acids (NEFA) on 35 d (P < 0.05). Dietary BAs supplementation significantly alleviated the hepatic TG deposition induced by HFD (P < 0.05), which was accompanied by upregulation of peroxisome proliferator-activated receptor gamma (PPARγ) and lipoprotein lipase (LPL) gene expression (P < 0.05). Moreover, the expression levels of hepatic gene adipose triglyceride lipase (ATGL), peroxisome proliferator-activated receptor α (PPARα), and apolipoprotein B (APOB) were greatly increased by BAs treatment. The analysis of 16S rRNA sequencing showed that the microbial diversity of the cecal digesta was increased by BAs in broilers with elevated abundances of Firmicutes, Lactobacillus, Anaerostipes, Sellimonas, and CHKCI002 and decreased abundances of Barnesiella and Akkermansia genus (P < 0.05). Hepatic TG content was positively correlated with the abundance of Oscillospiraceae, but it was negatively correlated with the abundance of Lactobacillus in cecal digesta (P < 0.05). These results indicate that dietary BAs can improve growth performance and alleviate fatty liver disease induced by an HFD via modulating gut microbiota in broilers.

Effect of Tea Polyphenols, α-Lipoic Acid and Their Joint Use on the Antioxidant and Lipid Metabolism Performance of Hybrid Grouper (♀Epinephelus fuscoguttatus × ♂E. lanceolatu) Fed with High-Lipid Diets.

This study investigated tea polyphenols (TP), α-lipoic acid (ALA) and their joint use on the antioxidant and lipid metabolic performance of hybrid grouper (♀Epinephelus fuscoguttatus × ♂E. lanceolatu) took food with high-fat diets. Six high-lipid diets with isonitrogen (50% of dry matter) and isolipid (17% of dry value) were designed, in which a total content of 1,000 mg/kg additives were added to each group except for the control group (FL). The additives addition ratios in each group were ALA (AL), TP (PL), ALA : TP = 1 : 1 (EL), ALA : TP = 1 : 2 (OL), ALA : TP = 2 : 1 (TL). Each diet was divided into three repeat groups with 30 tails (6.84 ± 0.01 g) in each group and fed for 8 weeks. The consequences were as follows: (1) the highest weight gain rate, specific growth rate, as well as the lowest feed conversion ratio and ingestion rate were discovered in the OL team, which were opposite to the TL group. (2) The body fat content and muscle fat content in the fish oil group were the lowest (P < 0.05), while those of the TL group were the highest. (3) Serum catalase, glutathione peroxidase, total antioxidant capacity, and superoxide dismutase activities were the highest, and the content of reactive oxygen species was the lowest in the OL group. (4) The OL group has the highest hepatic lipase activity and the lowest very low-density lipoprotein content of the liver. In contrast, the TL group had the highest fatty acid synthetase (FAS) activity (P < 0.05). (5) The oil-red aspects of liver tissue displayed lipid particles in other groups were reduced to different degrees compared with FL group, and the OL group showed the best lipid-lowering effect. (6) Compared with the FL group, the relative expressions of FAS, acetyl-CoA carboxylase (acc), and apolipoprotein b-100 (apoB100) genes in the liver were decreased. The relative expressions of lipoprotein lipase (lpl) and peroxisome proliferators-activated receptors-α (pparα) genes related to lipid catabolism were increased, among which the OL group had the most significant change (P < 0.05). (7) According to the 7-day challenge test of Vibrio alginolyticus, the OL group had the highest survival rate. To sum up, both ALA and TP have positive effects on relieving the lipid metabolism disorder of hybrid grouper. If they are jointly used, adding ALA : TP in a ratio of 1 : 2 (OL) may have the best effect, and an addition ratio of 2 : 1 (TL) may inhibit the hybrid grouper growth and increase the feeding cost.

FATP4 deletion in liver cells induces elevation of extracellular lipids via metabolic channeling towards triglycerides and lipolysis

Evidence from mice with global deletion of fatty-acid transport protein4 (FATP4) indicates its role on β-oxidation and triglycerides (TG) metabolism. We reported that plasma glycerol and free fatty acids (FA) were increased in liver-specific Fatp4 deficient (L-FATP4−/−) mice under dietary stress. We hypothesized that FATP4 may mediate hepatocellular TG lipolysis. Here, we demonstrated that L-FATP4−/− mice showed an increase in these blood lipids, liver TG, and subcutaneous fat weights. We therefore studied TG metabolism in response to oleate treatment in two experimental models using FATP4-knockout HepG2 (HepKO) cells and L-FATP4−/− hepatocytes. Both FATP4-deificient liver cells showed a significant decrease in β-oxidation products by ∼30–35% concomitant with marked upregulation of CD36, FATP2, and FATP5 as well as lipoprotein microsomal-triglyceride-transfer protein genes. By using 13C3D5-glycerol, HepKO cells displayed an increase in metabolically labelled TG species which were further increased with oleate treatment. This increase was concomitant with a step-wise elevation of TG in cells and supernatants as well as the secretion of cholesterol very low-density and high-density lipoproteins. Upon analyzing TG lipolytic enzymes, both mutant liver cells showed marked upregulated expression of hepatic lipase, while that of hormone-sensitive lipase and adipose-triglyceride lipase was downregulated. Lipolysis measured by extracellular glycerol and free FA was indeed increased in mutant cells, and this event was exacerbated by oleate treatment. Taken together, FATP4 deficiency in liver cells led to a metabolic shift from β-oxidation towards lipolysis-directed TG and lipoprotein secretion, which is in line with an association of FATP4 polymorphisms with blood lipids.

Intermittent Fasting Attenuates Metabolic-Dysfunction-Associated Steatohepatitis by Enhancing the Hepatic Autophagy-Lysosome Pathway.

An intermittent fasting (IF) regimen has been shown to protect against metabolic dysfunction-associated steatohepatitis (MASH). However, the precise mechanism remains unclear. Here, we explored how IF reduced hepatic lipid accumulation, inflammation, and fibrosis in mice with MASH. The mice were fed a high-fat diet (HFD) for 30 weeks and either continued on the HFD or were subjected to IF for the final 22 weeks. IF reduced body weight, insulin resistance, and hepatic lipid accumulation in HFD-fed mice. Lipidome analysis revealed that IF modified HFD-induced hepatic lipid composition. In particular, HFD-induced impaired autophagic flux was reversed by IF. The decreased hepatic lysosome-associated membrane protein 1 level in HFD-fed mice was upregulated in HFD+IF-fed mice. However, increased hepatic lysosomal acid lipase protein levels in HFD-fed mice were reduced by IF. IF attenuated HFD-induced hepatic inflammation and galectin-3-positive Kupffer cells. In addition to the increases in hepatic hydroxyproline and lumican levels, lipocalin-2-mediated signaling was reversed in HFD-fed mice by IF. Taken together, our findings indicate that the enhancement of the autophagy-lysosomal pathway may be a critical mechanism of MASH reduction by IF.

Lycopene Alleviates the Adverse Effects of Feeding High-Lipid Diets to Hybrid Grouper (♀Epinephelus fuscoguttatus ×♂E. lanceolatus).

It has been found that high-lipid diets (HLDs) disrupt lipid metabolism in fish, leading to an excessive accumulation of lipids in various tissues of the fish body. The objective of this study was to investigate if the inclusion of lycopene (LCP) in an HLD may mitigate the adverse consequences of excessive dietary lipid intake in hybrid grouper (♀ Epinephelus fuscoguttatus × ♂ E. lanceolatus). The experimental design incorporated a control group (L0), which was administered a diet consisting of 42% protein and 16% lipid. The diets for groups L1, L2, and L3 were developed by augmenting the control diet with 100, 200, and 400 mg/kg LCP, respectively. The duration of the trial spanned a period of 42 days. The results of the study showed that the weight gain rate (WGR) and protein efficiency ratio (PER) of the three LCP treatment groups (L1, L2, and L3) tended to increase and then decrease, with a significant increase in WGR and PER in L2 (P < 0.05). Visceral somatic index and hepatic somatic index tended to decrease and then increase in all treatment groups, with a significant decrease in L2 (P < 0.05). In serum dietary LCP significantly reduced triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL) content and significantly increased high-density lipoprotein (HDL) content (P < 0.05). In the liver, dietary LCP reduced TC, TG, and very LDL levels and improved lipoprotein lipase, hepatic lipase, fatty acid (FA) synthetase, and acetyl-CoA carboxylase activities. The number and area of hepatic lipid droplets decreased significantly with increasing LCP content. In the liver, the addition of appropriate levels of LCP significantly upregulated lipoprotein lipase (lpl) and peroxisome proliferator-activated receptor α (pparα). In summary, dietary LCP improves growth and reduces lipid deposition in the liver of hybrid grouper by increasing lipolytic metabolism and decreasing FA synthesis. Under the experimental conditions, the fitted curve analysis showed that the recommended LCP additions to the high lipid diet for juvenile hybrid grouper were 200-300 mg/kg.

Different Dietary Sources of Selenium Alleviate Hepatic Lipid Metabolism Disorder of Heat-Stressed Broilers by Relieving Endoplasmic Reticulum Stress.

As global warming continues, the phenomenon of heat stress (HS) in broilers occurs frequently. The alleviating effect of different selenium (Se) sources on HS-induced hepatic lipid metabolism disorders in broilers remains unclear. This study compared the protective effects of four Se sources (sodium selenite; selenium yeast; selenomethionine; nano-Se) on HS-induced hepatic lipid metabolism disorder and the corresponding response of selenotranscriptome in the liver of broilers. The results showed that HS-induced liver injury and hepatic lipid metabolism disorder, which were reflected in the increased activity of serum alanine aminotransferase (ALT), the increased concentration of triacylglycerol (TG) and total cholesterol (TC), the increased activity of acetyl-CoA carboxylase (ACC), diacylglycerol O-acyltransferase (DGAT) and fatty acid synthase (FAS), and the decreased activity of hepatic lipase (HL) in the liver. The hepatic lipid metabolism disorder was accompanied by the increased mRNA expression of lipid synthesis related-genes, the decreased expression of lipidolysis-related genes, and the increased expression of endoplasmic reticulum (ER) stress biomarkers (PERK, IRE1, ATF6, GRP78). The dietary supplementation of four Se sources exhibited similar protective effects. Four Se sources increased liver Se concentration and promoted the expression of selenotranscriptome and several key selenoproteins, enhanced liver antioxidant capacity and alleviated HS-induced ER stress, and thus resisted the hepatic lipid metabolism disorders of broilers exposed to HS. In conclusion, dietary supplementation of four Se sources (0.3 mg/kg) exhibited similar protective effects on HS-induced hepatic lipid metabolism disorders of broilers, and the protective effect is connected to the relieving of ER stress.

Dietary soybean lecithin promoted growth performance and feeding in juvenile Chinese perch (Siniperca chuatsi) could be by optimizing glucolipid metabolism.

To explore the potential benefits of dietary phospholipids (PLs) in fish glucose metabolism and to promote feed culture of Chinese perch (Siniperca chuatsi), we set up six diets to feed Chinese perch (initial mean body weight 37.01 ± 0.20 g) for 86 days, including: Control diet (CT), 1% (SL1), 2% (SL2), 3% (SL3), 4% (SL4) soybean lecithin (SL) and 2% (KO2) krill oil (KO) supplemental diets (in triplicate, 20 fish each). Our study found that the SL2 significantly improved the weight gain rate and special growth rate, but the KO2 did not. In addition, the SL2 diet significantly improved feed intake, which is consistent with the mRNA levels of appetite-related genes (npy, agrp, leptin A). Additionally, in the CT and SL-added groups, leptin A expression levels were nearly synchronized with serum glucose levels. Besides, the SL2 significantly upregulated expression levels of glut2, gk, cs, fas and downregulated g6pase in the liver, suggesting that it may enhance glucose uptake, aerobic oxidation, and conversion to fatty acids. The SL2 also maintained the hepatic crude lipid content unchanged compared to the CT, possibly by significantly down-regulating the mRNA level of hepatic lipase gene (hl), and by elevating serum low-density lipoprotein (LDL) level and intraperitoneal fat ratio in significance. Moreover, the serum high-density lipoprotein levels were significantly increased by PL supplementation, and the SL2 further significantly increased serum total cholesterol and LDL levels, suggesting that dietary PLs promote lipid absorption and transport. Furthermore, dietary SL at 1% level could enhance non-specific immune capacity, with serum total protein level being markedly higher than that in the CT group. In conclusion, it is speculated that the promotion of glucose utilization and appetite by 2% dietary SL could be linked. We suggest a 1.91% supplementation of SL in the diet for the best growth performance in juvenile Chinese perch.

FRI089 Massive Hypertriglyceridemia? Think Oral Contraceptive Pills!

Abstract Disclosure: I. Ali: None. M. Hamdi: None. Introduction: Oral contraceptive pills (OCPs) are common cause of Hypertriglyceridemia (TG) that should be recognized early by clinicians. Concern is raised regarding pursing further genetic test for Familial hypertriglyceridemia for female who developed massive hyper triglyceridemic after starting hormonal therapy. Case: A 37-year-old female patient with history of prediabetes with A1c of 5.7% and one attack of pancreatitis. Normal BMI, No regular medications, negative family history for lipid disorder. Rare social intake of alcohol. Routine annual lab showed triglycerides level of 164 in 2016, otherwise normal biochemical evaluation. No treatment pursued. Later She was started on OCPs (Kariva 0.15-0.02 mg) for contraception. Late 2019, blood work-up showed cholesterol level of 979, TG of 3170 and HDL level of 22. She was started on a statin therapy and fenofibrates beside stopping OCP, she maintained normal lipid profile while being off OCPs, until 2022 when she restarted an OCPs (Lo Loestrin 1mg-10 mcg) for 2 months that resulted in elevated cholesterol level of 1222, triglycerides of 5177 and HDL of 10.OCP was stopped, lipids level trended down with cholesterol of 961, triglycerides of 2005 and HDL of 22 then normalized after 2 months. Patient did not have any clinical symptom or complain. Discussion: High triglyceride concentration is an independent predictor of coronary heart disease and ischemic stroke. Many patients with triglycerides &amp;gt;1000 mg/dl have familial hypertriglyceridemia with superimposed additional exogenous factors which further raise triglyceride concentrations like exogenous estrogens, SERMs, hyperestrogenemia of pregnancy, poorly controlled diabetes mellitus, hypothyroidism, alcohol excess, exogenous corticosteroids, and drugs including isotretinoin and protease inhibitors. OCP induced hypertriglyceridemia occurs due to estrogen’s action in decreasing hepatic triglyceride lipase and lipoprotein lipase activity. This causes an overall increase in low and intermediate-density triglycerides and cholesterol that can increase free fatty acids to toxic level. The marked increase of TG and cholesterol in this patient while being on OCP is unusual and strongly indicate underlying familial hypertriglyceridemia exacerbated by starting OCP. Further genetic work up is being done. As OCP or other estrogen therapy are frequently given unwittingly to women with preexisting hypertriglyceridemia that lead to severe clinical consequences. Estrogen containing medication should not be considered if fasting triglyceride is above 500 mg/dl. In women on hormonal treatment with treatment-resistant hypertriglyceridemia, the likelihood that the hormonal treatment is nullifying drug efficacy is high so it should be stopped for a short trial while continuing modifying triglyceride-lowering medications. Presentation: Friday, June 16, 2023

Carya cathayensis Leaf Extract Exerts Estrogenic Effects on Hepatic Lipogenesis and Adipocytes Differentiation in Ovariectomized Rats Fed Normal or High-fat Diets

Our previous study has shown that total flavonoids from the leaves of C arya . cathayensis exert estrogenic activities by promoting the expressions of ERα, ERβ in vitro study. C. cathayensis leaf extract (CCE) was rich in flavonoids. Oral administration of CCE reduced the serum lipids and hepatic lipids, alleviated liver steatosis in ovariectomized rats. To investigate whether CCE has estrogenic effects on reproductive tissue and lipid metabolism in ovariectomized rats, and whether CCE has a direct effect on regulation of lipid synthesis and/or oxidation and adipocyte differentiation of ovariectomized (OVX) rats. Sprague–Dawley rats were ovariectomized and treated with CCE or estradiol in combination with a normal diet (ND), a high-fat diet (HFD) for 8 weeks. Histological analysis of uterus were performed and the lipid metabolism-related enzyme activity were examined. Expression of liver lipogenesis-related genes, adipocyte differentiation-and fat accumulation-related genes and protein were measured. Ovariectomy accelerated the uterine atrophy, development of dyslipidemia and hepatic steatosis, which were effectively mitigated by CCE supplementation. CCE significantly elevated ovariectomy-induced reduction in the cross-section area of the uterus and uterine glands. Compared with the OVX group, CCE increased the activities of lipoprtein lipase (LPL) and hepatic lipase (HL), decreased the hepatic mRNA expressions of Fas, Srebf1 , and Sla2a2 and increased Ppar α expressions at the mRNA levels under both ND and HFD conditions. CCE also decreased the Pck1 and G6pc mRNA expressions under HFD conditions, and show no significant effects on Hmgcr . The expressions of SREBP-1c, CEBPA and VEGF at the protein level were effectively regulated by CCE supplementation. CCE effectively alleviated ovariectomy-induced dyslipidemia and visceral fat accumulation by modulating hepatic lipogenesis and adipocyte differentiation. Furthermore, CCE exhibited estrogenic activity for the prevention of postmenopausal fatty liver.

Methionine supplemented in a high fat-diet: Effects of growth performance and lipid metabolism in rice field eel (Monopterus albus)

An eight-week feeding trial explored the mechanism of methionine supplementation (0 g/kg, 4 g/kg, 8 g/kg, 12 g/kg) in a high-fat diet (120 g/kg fat, HFD) on the growth performance and hepatic lipid metabolism of M. albus (initial weight 25.03 ± 0.13 g) based on a basic diet (60 g/kg fat), named as Con, HFD+M0, HFD+M4, HFD+M8, HFD+M12, respectively. 1) Compared with Con, high-fat diet decreased the survival rate and weight gain rate of M. albus, and significantly enhanced the feed conversion rate, hepatopancreas index and crude lipid content of M. albus (P < 0.05). Compared with HFD + M0, supplemented methionine markedly enhanced weight gain rate of M. albus (P < 0.05), and significantly decreased feed conversion rate and crude lipid content of M. albus (P < 0.05). 2) Compared with Con, hepatic lipoprotein lipase, fatty acid synthetase, triglyceride, cholesterol and fatty acid (C18:2n6, C20:5n3, SFA and MUFA) of HFD + M0 were markedly improved (P < 0.05); compared with HFD + M0, hepatic fatty acid synthase, triglyceride, cholesterol and fatty acid (C18:0, SFA and n-6PUFA) of HFD + M8 were significantly decreased (P < 0.05). Additionally, the proportion of hepatic vacuoles of HFD + M0 was higher than that in Con; compared with HFD + M0, hepatic cells of HFD + M8 were more regularly, and the proportion of hepatic vacuoles and lipid droplets decreased. 3) Compared with Con, hepatic srebf2, hsl, lpl, srebf1, cpt1 and cpt2 were remarkably up-regulated in HFD+M0 (P < 0.05); compared with HFD+M0, hepatic gcn2, eif2a, srebf2, srebf1 and fas were remarkably down-regulated in HFD+M8 (P < 0.05). Additionally, compared with HFD + M0, SREBP1 protein expression of HFD + M8 were markedly down-regulated (P < 0.01). In conclusion, dietary methionine mainly reduced hepatic lipid abnormal deposition by reducing hepatic fatty acid synthesis.

Dietary Effects of Lipid and Protein Levels on Growth, Feed Utilization, Lipid Metabolism, and Antioxidant Capacity of Triploid Rainbow Trout (Oncorhynchus mykiss).

This study investigated the dietary effects of lipid and protein levels on growth performance, feed utilization, body composition, lipid metabolism, and antioxidant capacity of triploid rainbow trout, Oncorhynchus mykiss. A 3 × 2 two-factor design was conducted with three crude lipid levels of 4%, 9%, and 14% (L4, L9, and L14) and two crude protein levels of 44%, 49% (P44, P49). Therefore, a total of six diets were prepared as P44/L4, P44/L9, P44/L14, P49/L4, P49/L9, and P49/L14. Triploid rainbow trout (initial body weight 65.0 ± 0.1 g) were fed one of the six diets for 80 days. The results showed that weight gain (WG), protein retention (PR), and protein efficiency rate (PER) significantly increased with increasing the dietary lipid level at the same crude protein level, while feed conversion ratio (FCR) and hepatosomatic index significantly decreased (P < 0.05). At the same lipid level, there was no difference in WG, FCR, PR, PER between 44% and 49% crude protein group (P > 0.05). The P49/L14 group had the highest WG (374.6%) and lowest FCR (1.25), while P44/L14 group had the highest PER (1.80) and PR (25.06%) with similar WG and FCR to P49/L14 group. The crude lipid contents in whole fish were significantly higher in the L14 group than those in the L4 and L9 groups (P < 0.05). Muscle n-3 PUFAs, n-6 PUFAs, and PUFAs levels were positively correlated with dietary lipid level, while n-6 PUFAs was negatively correlated with dietary protein level. Dietary protein, dietary lipid, and their interaction significantly affected hepatic malondialdehyde (MDA) content, aspartate aminotransferase, lipase (LPS), and fatty acid synthase (FAS) activities (P < 0.05). In both P44 and P49 groups, LPS and FAS activities increased with increasing the dietary lipid level. MDA content significantly decreased in the P44 group and increased in the P49 group with increasing the dietary lipid level (P < 0.05). As dietary protein level increased, serum total cholesterol level increased, while hepatic phosphoenolpyruvate carboxykinase activity decreased. With increasing the dietary lipid level, total superoxide dismutase, catalase, total nitric oxide synthase, and fructose-1,6-bisphosphatase activities showed an increasing trend, while the opposite was true for alanine aminotransferase activity. In conclusion, based on growth performance and feed utilization, dietary protein level of 44% and dietary lipid level of 14% (measured value, 43.71% and 13.62%) were suggested for young triploid rainbow trout.

Dietary choline activates the Ampk/Srebp signaling pathway and decreases lipid levels in Pacific white shrimp (Litopenaeus vannamei)

An 8-week feeding trial was conducted in Pacific white shrimp (Litopenaeus vannamei) to evaluate the effects of dietary choline supplementation on choline transport and metabolism, hepatopancreas histological structure and fatty acid profile, and regulation of lipid metabolism. Six isonitrogenous and isolipidic diets were formulated to contain different choline levels of 2.91 (basal diet), 3.85, 4.67, 6.55, 10.70 and 18.90 g/kg, respectively. A total of 960 shrimp (initial weight, 1.38 ± 0.01 g) were distributed randomly into twenty-four 250-L cylindrical fiber-glass tanks, with each diet assigned randomly to 4 replicate tanks. The results indicated that dietary choline significantly promoted the deposition of choline, betaine and carnitine (P < 0.05). The diameters and areas of R cells, total lipid and triglyceride contents in hepatopancreas, and triglyceride and non-esterified fatty acid contents in hemolymph were negatively correlated with dietary choline level. The contents of functional fatty acids in hepatopancreas, the activity of acetyl-CoA carboxylase (Acc), and the mRNA expression of fas, srebp and acc were highest in shrimp fed the diet containing 4.67 g/kg choline, and significantly higher than those fed the diet containing 2.91 g/kg, the lowest level of choline (P < 0.05). The number of R cells, content of very low-density lipoprotein (VLDL), activities of carnitine palmitoyl-transferase (Cpt1), lipoprotein lipase and hepatic lipase, and the mRNA expression levels of cpt1, fabp, fatp, ldlr, and ampk in hepatopancreas increased significantly as dietary choline increased (P < 0.05). In addition, hepatopancreas mRNA expression levels of ctl1, ctl2, oct1, badh, bhmt, ck, cept, and cct were generally up-regulated as dietary choline level increased (P < 0.01). In conclusion, dietary choline promoted the deposition of choline and its metabolites by up-regulating genes related to choline transport and metabolism. Moreover, appropriate dietary choline level promoted the development of hepatopancreas R cells and maintained the normal accumulation of lipids required for development, while high dietary choline not only promoted hepatopancreas lipid export by enhancing VLDL synthesis, but also promoted fatty acid β-oxidation and inhibited de novo fatty acid synthesis by activating the Ampk/Srebp signaling pathway. These findings provided further insight and understanding of the mechanisms by which dietary choline regulated lipid metabolism in L. vannamei.

Effects of diel-cycling hypoxia and salinity on lipid metabolism and fatty acid composition of the oyster Crassostrea hongkongensis

For marine animals living in estuarine, coastal, and intertidal areas, salinity changes and periodic hypoxia are typical stressors; however, how the varying salinity and dissolved oxygen affect the quality and nutrition of marine aquaculture species, such as oysters remains unknown. In this study, we evaluated the diel-cycling hypoxia under different salinities on fatty acid composition and lipid metabolism in oyster Crassostrea hongkongensis digestive glands. After 28 days of exposure, both hypoxia and elevated salinity caused a decrease in the saturated fatty acid (SFA)/polyunsaturated fatty acid (PUFA) ratio of C. hongkongensis, salinity mainly causes changes in C17:0, C17:1, C18:1n9, C20:1n9, C20:4n6, C21:5n3, C22:5n3, with high salinity being more damaging to the fatty acid fractions. Also, Hypoxia accelerates the synthesis of C18:1n9 and C20:4n6. Fatty acid synthase (FAS) synthesis is increased by reduced salinity or hypoxia, but Acetyl CoA carboxylase (ACC) only weakly promotes fatty acid synthesis. Under hypoxic conditions, the activity of both hepatic lipase (HL) and lipoprotein lipase activity (LPL) decreases, which is contrary to the results for dissolved oxygen. The increase in salinity under dissolved oxygen leads to a decrease in LPL activity and an increase in HL activity. Our findings highlighted that exposure to a combination of salinity and hypoxia stressors, can disrupt the protective mechanisms of the oyster and affect the function of its lipid metabolism. Therefore, long-term exposure to periodic hypoxia with salinity changes poses a risk to the nutritional quality of C. hongkongensis, affecting oyster aquaculture and the coastal ecosystem.

Lippia javanica (Burm. F.) Herbal Tea: Modulation of Hepatoprotective Effects in Chang Liver Cells via Mitigation of Redox Imbalance and Modulation of Perturbed Metabolic Activities.

Introduction: Hepatic oxidative injury is one of the pathological mechanisms that significantly contributes to the development of several liver diseases. In the present study, the hepatoprotective effect of Lippia javanica herbal tea was investigated in Fe2+- mediated hepatic oxidative injury. Methods: Using an in vitro experimental approach, hepatic oxidative injury was induced by co-incubating 7mM FeSO4 with Chang liver cells that have been pre-incubated with or without different concentrations (15-240μg/mL) of L. javanica infusion. Gallic acid and ascorbic acid served as the standard antioxidants. Results: The infusion displayed a reducing antioxidant activity in ferric-reducing antioxidant power (FRAP) assay and a potent scavenging activity on 2,2-diphenyl-2- picrylhydrazyl (DPPH) radical. Pretreatment with L. javanica infusion significantly elevated the levels of reduced glutathione and non-protein thiol, and the activities of superoxide dismutase (SOD) and catalase, with concomitant decrease in hepatic malondialdehyde levels, acetylcholinesterase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, glycogen phosphorylase and lipase activities. The infusion showed the presence of phytoconstituents such as phenolic compounds, tannins, phenolic glycosides and terpenoids when subjected to liquid chromatography-mass spectrometry analysis. Molecular docking revealed a strong binding affinity of dihydroroseoside and obacunone with both SOD and catalase compared to other phytoconstituents. Conclusion: These results portray a potent antioxidant and hepatoprotective effect of L. javanica, which may support the local usage of the herbal tea as a prospective therapeutic agent for oxidative stress-related liver diseases.

Improvements in the growth performance, morphology, gut microbiota, hepatic health, and immune response of juvenile tilapia (Oreochromis niloticus) fed Metschnikowia sp. GXUS03

The present study investigated the effects of dietary Metschnikowia sp. GXUS03 on the growth performance, morphology, intestinal flora, hepatic health, and immune response of juvenile tilapia (Oreochromis niloticus). The fish (average weight = 9.67 ± 1.61 g) were administered either a plain basal diet (control check group; CK), a basal diet supplemented with 1 × 107 CFU/g GXUS03 (M01 group), or a basal diet supplemented with 1 × 108 CFU/g GXUS03 (M02 group) for eight weeks. Relative to CK, M01 and M02 had significantly higher final body weights (FBW), weight gain rates (WGR), specific growth rates (SGR), and feed conversion ratios (FCR) (P < 0.05) as well as less hepatic fat vacuolation. M02 also presented significantly upregulated antioxidant enzymes and enhanced antioxidant capacity. After eight weeks, M01 and M02 also exhibited significantly improved autochthonous gut bacterial community and the formation of various potential probiotics. M02 displayed significantly improved survival in response to Streptococcus agalactiae inoculation. This treatment augmented lipid metabolism and the immune response, increased the serum index (complement 3 content and lysozyme activity), and upregulated hepatic Toll-like receptor (TLR2, MyD88), lipoprotein lipase (LPL), and immune-related (C3, lyz) genes. The foregoing results indicate that 1 × 108 CFU/g Metschnikowia sp. GXUS03 dietary supplementation improved the growth performance indices, liver health, and immune responses in tilapia.

Dietary inositol improved glucose and lipid metabolism mediated by the Insulin-PI3K-Akt signaling pathway in Pacific white shrimp (Litopenaeus vannamei)

The present study aimed to evaluate the effects of dietary inositol level (0.86, 1.34, 1.40, 2.30, 3.88 and 7.50 g kg−1) on glucose and lipid homeostasis in Litopenaeus vannamei. The results indicated that the contents of inositol, phosphatidyl inositol (PI) and glycogen in hepatopancreas and muscle, very low-density lipoprotein (VLDL) in hepatopancreas and hemolymph, the activity of carnitine palmitoyl-transferase (CPT1) and the expression of hmit and inox were positively related to the dietary inositol levels, while the contents of glucose (GLU), crustacean hyperglycemic hormone (CHH), triglyceride (TG), cholesterol (CHO) and non-esterified fatty acid (NEFA) in hemolymph and the expression of imp, pepck, g6pc and fbp were negatively correlated with the dietary inositol level. TG content, phosphoenolpyruvate carboxykinase (PEPCK) activity and the expression levels of srebp, fas, acc1, g6pd and 6gpd in shrimp fed 3.88 and 7.50 g kg−1 inositol diets were significantly lower compared with shrimp fed the basal diet, while the expression of cpt1, aco, fabp, fatp and idir were showed the reverse change trend (P < 0.05). The activities of hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK) and the expression levels of ir, irs1, pi3k and akt were significantly increased as dietary inositol levels ranged from 1.40 to 7.50 g kg−1, while the expression levels of gsk-3β and foxo1 significantly down-regulated. Hepatopancreas R cells number in shrimp fed 2.30, 3.88 and 7.50 g kg−1 inositol diets were significantly increased compared with shrimp fed 0.86 g kg−1 inositol diet, while the diameters and areas showed an opposite trend. In addition, dietary inositol supplementation significantly increased hemolymph insulin like peptide (ILP) content but had no significant effect on high density lipoprotein cholesterol (HLDC) content in hemolymph, hepatic lipase (HL) activity and the ratio of n-3/ n-6 PUFA and DHA/EPA in hepatopancreas. In conclusion, appropriate dietary inositol could positively regulate the Insulin-PI3K-Akt pathway to promote glucose utilization and maintain the normal accumulation of glycogen and lipids required for development, while high dietary inositol could promote lipid mobilization and prevent hepatopancreas lipids deposition by negatively regulating the Insulin-PI3K-Akt pathway, improving ILP sensitivity and enhancing VLDL synthesis, which may therefore be an important mechanism in the action of inositol on glucose and lipid metabolism. These findings provided further insight and understanding of mechanisms by which dietary inositol regulated glucose and lipid metabolism in L. vannamei.

Indigestible Dextrin Alleviates the Intestinal Absorption of Alpha-linolenic Acid More Markedly Than That of Linoleic Acid in Obese Mice

Linoleic acid (LA) and alpha-linolenic acid (ALA) constitute the main dietary polyunsaturated fatty acids. Indigestible dextrin (DEX) is a dietary fiber that causes a beneficial decrease in lifestyle-related disease risk factors. We investigated the effects of DEX on intestinal absorption of LA and ALA in obese mice. KK-Ay/TaJcl obese mice were fed an ALA- or LA-abundant diet and provided with water in the absence and presence of 0.06 w/v% DEX for 4 weeks. The levels of lipids in serum samples and the lipase activity in serum and liver were analyzed. The effects of DEX on the intestinal absorption of LA and ALA were investigated using an in vitro model of the intestinal absorption process in the fed-state simulated intestinal fluid (FeSSIF) solution. ALA resulted in an increase in the serum triglyceride (TG) levels than those observed upon feeding an LA-abundant diet. DEX suppressed significantly the ALA-dependent increase in serum TG levels. Neither LA nor ALA affected the serum levels of total cholesterol and high-density lipoprotein cholesterol, as well as the serum and hepatic lipase activities. Moreover, ALA showed better solubility than LA in FeSSIF solution. The solubility of ALA in FeSSIF solution was significantly suppressed by DEX, whereas that of LA was not affected by DEX. ALA can be absorbed more easily than LA during the intestinal absorption process, probably leading to an increase in the serum TG levels and then DEX more selectively inhibits the intestinal absorption of ALA compared to that of LA.

LC–MS/MS based characterisation and differential expression of proteins in Himalayan snow trout, Schizothorax labiatus using LFQ technique

Molecular characterization of fish muscle proteins are nowadays considered as a key component to understand the role of specific proteins involved in various physiological and metabolic processes including their up and down regulation in the organisms. Coldwater fish specimens including snow trouts hold different types of proteins which help them to survive in highly diversified temperatures fluctuating from 0 to 20 °C. So, in current study, the liquid chromatography mass spectrometry using label free quantification technique has been used to investigate the muscle proteome profile of Schizothorax labiatus. For proteomic study, two weight groups of S. labiatus were taken from river Sindh. The proteomic analysis of group 1 revealed that a total of 235 proteins in male and 238 in female fish were recorded. However, when male and female S. labiatus were compared with each other on the basis of spectral count and abundance of peptides by ProteinLynx Global Server software, a total of 14 down-regulated and 22 up-regulated proteins were noted in this group. The highly down-regulated ones included homeodomain protein HoxA2b, retinol-binding protein 4, MHC class II beta chain and proopiomelanocortin while as the highly expressed up-regulated proteins comprised of gonadotropin I beta subunit, NADH dehydrogenase subunit 4, manganese superoxide dismutase, recombinase-activating protein 2, glycosyltransferase, chymotrypsin and cytochrome b. On the other hand, the proteomic characterisation of group 2 of S. labiatus revealed that a total of 227 proteins in male and 194 in female fish were recorded. When male and female S. labiatus were compared with each other by label free quantification, a total of 20 down-regulated and 18 up-regulated proteins were recorded. The down-regulated protein expression of group 2 comprised hepatic lipase, allograft inflammatory factor-1, NADH dehydrogenase subunit 4 and myostatin 1 while the highly expressed up-regulated proteins included glycogen synthase kinase-3 beta variant 2, glycogen synthase kinase-3 beta variant 5, cholecystokinin, glycogen synthase kinase-3 beta variant 3 and cytochrome b. Significant (P < 0.05) difference in the expression of down-regulated and up-regulated proteins was also noted between the two sexes of S. labiatus in each group. According to MS analysis, the proteins primarily concerned with the growth, skeletal muscle development and metabolism were down-regulated in river Sindh, which indicates that growth of fish during the season of collection i.e., winter was slow owing to less food availability, gonad development and low metabolic activity. While, the proteins related to immune response of fish were also noted to be down-regulated thereby signifying that the ecosystem has less pollution loads, microbial, pathogenic and anthropogenic activities. It was also found that the proteins involved in glycogen metabolism, reproductive and metabolic processes, particularly lipid metabolism were up-regulated in S. labiatus. The significant expression of these proteins may be connected to pre-spawning, gonad development and use of stored food as source of energy. The information generated in this study can be applied to future research aimed at enhancing food traceability, food safety, risk management and authenticity analysis.