Lipase Research Articles

Study on the chemical constituents of the aerial parts of Polygonatum sibiricum and its pancreatic lipase inhibitory activity

Study on the chemical constituents of the aerial parts of Polygonatum sibiricum and its pancreatic lipase inhibitory activity

Effect of somatostatin combined with magnesium sulfate in treatment of severe acute pancreatitis

Objective To explore the efficacy of somatostatin combined with magnesium sulfate in the treatment of patients with severe acute pancreatitis(SAP)and its effects on the levels of serum amylase(AMS), serum lipase(LPS)and inflammatory factors. Methods A total of 76 SAP patients were randomly divided into control group(n=38, treated with somatostatin)and observation group(n=38, treated with somatostatin and magnesium sulfate). The therapeutic effect and complications were compared between the two groups, and the levels of serum AMS, LPS and inflammatory factors before and after treatment were compared between the two groups. Results The total effective rate in the observation group was 94.74%, which was significantly higher than 78.95% in the control group(P<0.05). The levels of LPS and AMS after treatment in the observation group were significantly lower than those in the control group(P<0.05). The C-reactive protein(CRP), tumor necrosis factor-α(TNF-α)and interlenkin-6(IL-6)levels after treatment in the observation group were significantly lower than those in the control group(P<0.05). The incidence of complications in the observation group was 5.26%, which was significantly lower than 21.05% in the control group(P<0.05). Conclusion Somatostatin combined with magnesium sulfate is effective in the treatment of SAP patients, which can improve the levels of serum AMS and LPS, reduce the levels of inflammatory factors, and alleviate pancreatic injury.

Survival and Growth Promoting Effects of Bacillus subtilis on Macrobrachium rosenbergii, and Validation of Gut Microflora

This work emphasized the survival and growth of the commercially important freshwater prawn, Macrobrachium rosenbergii post-larvae on formulated diets supplemented with a probiotic bacterium, Bacillus subtilis at five different serially diluted concentrations (10-1, 10-3, 10-5, 10-7 and 10-9). After 90 days of feeding, 10-7 (CFU, 2.76×10-7) concentration has produced the best results in increased survival rate, weight gain, basic biochemical constituents (total protein, amino acid, carbohydrate and lipid) and activities of digestive enzymes (protease, amylase and lipase) when compared with control diet prepared without B. subtilis. This was due to maintenance of good intestinal health, because of B. subtilis supplementation. The presence of B. subtilis, Bacillus cereus, Lactobacillus delbrueckii (subsp. bulgaricus), Lactobacillus casei, Lactobacillus rhamnosus and Streptococcus pyogenes have been identified in the gut of M. rosenbergii fed with B. subtilis supplemented diet, through 16S r-RNA gene sequencing and authenticated with NCBI GenBank. The pathogenic bacteria such as Escherichia coli, Klebsiella spp., and Staphylococcus spp., present in the control prawns as per our previous study (Manjula et al., 2018) have competitively been excluded by the experimental prawns fed with B. subtilis supplemented diet in the present study. Therefore, B. subtilis is recommended for sustainable production of M. rosenbergii seed.

Rapid detection of seven indexes in sheep serum based on Raman spectroscopy combined with DOSC-SPA-PLSR-DS model

Hepatic fascioliasis, ketosis of pregnancy, toxemia of pregnancy and other common sheep diseases will directly affect the concentration (/enzymatic activity) of seven indicators, such as cortisol and high-density lipoprotein cholesterol (HDL-C) in sheep serum. Whether the concentrations (/enzymatic activity) of these indicators can be detected quickly will directly affect the prevention of sheep diseases and the targeted adjustment of breeding methods, thereby affecting the economic benefits of sheep breeding. In this research, we established partial least square regression (PLSR), support vector regression based on genetic algorithm optimization (GA-SVR) and extreme learning machine (ELM) models. Due to the large differences in the content of different substances, it is difficult to directly use the RMSE to evaluate the quantitative effect of the model. This study is the first to propose conducting deviation standardization (DS) for the determination results of various substances. To further improve the performance of the model, we use the successive projections algorithm (SPA) to optimize feature extraction and combine it with the better-performing PLSR model for training. The results show that the optimized DOSC-SPA-PLSR-DS quantitative model has better determination results for 101 sheep serum samples. The average RMSEp* of the concentration of the six substances decreased from 0.0408 to 0.0387, the Rp2 increased from 0.9758 to 0.9846, and the running time was reduced from 0.1659 to 0.0008 s. And the determination performance of lipase (LPS) enzymatic activity has also been improved. The results of this research show that sheep serum Raman spectroscopy combined with DOSC-SPA-PLSR-DS optimization can efficiently monitor the concentration (/enzyme activity) of seven indicators in real time and provide a new strategy for future intelligent supervision of animal husbandry.

Hypertriglyceridemia-Induced Pancreatitis With Rapid Response to Insulin Therapy

Acute pancreatitis (AP) is one of the most common gastrointestinal-related causes of hospitalization in the USA, accounting for more than 200,000 admissions annually. Although mild and moderate cases usually improve within a week, severe AP conditions could lead to life-threatening pancreatic necrosis, multiple-organ dysfunction, and be fatal in some cases. Excessive alcohol use and gallstones are the two leading causes, nonetheless other systemic complication could also lead to AP. Hypertriglyceridemia is an important, yet uncommon, cause/risk factor of AP, especially when associated with heavy alcohol use. Additionally, the level of triglycerides (TGs) was found to be an important factor of determining the method and duration of treatment. Here we present a case of 38-year-old obese and active smoker male with hypertension and alcohol use disorder presented with a chief complaint of 2 weeks of progressive sharp epigastric pain. His medical history was significant of opioid use disorder that is maintained on methadone therapy. Computed tomography (CT) scan of the abdomen and pelvis revealed infiltration of the fat along the pancreatic tail and distal body with focus of decreased enhancement in the very distal pancreatic tail, which could represent a small infarct or phlegmon. In addition, laboratory data was significant of elevated lipase level (> 1,000 mg/dL), which together with the CT result confirmed the diagnosis of AP. Additional laboratory workup revealed extremely high level of TGs of > 2,000 mg/dL. The patient was subsequently transferred to the intensive care unit for management of hypertriglyceridemia. He was started on insulin therapy along with supportive treatment for the management of pancreatitis. Hypertriglyceridemia and pancreatitis rapidly improved over the course of hospitalization period and no additional intervention was needed. He was successfully discharged on fenofibrate. J Med Cases. 2021;12(1):23-26 doi: https://doi.org/10.14740/jmc3595

The metabolic suppressor 3-iodothyronamine enhances lipolysis in 3T3-L1 adipocytes via activation of the adenosine monophosphate-activated protein kinase/forkhead box O1 signaling pathway.

Obesity is a major health concern in modern societies as it is linked to diverse chronic diseases, such as diabetes, cancer, stroke, and skeletomuscular disorders. This study aimed to investigate the lipolytic potency of the metabolic suppressor 3-iodothyronamine (T1AM) and its molecular mechanism in differentiated 3T3-L1 adipocytes. Cells stained with Oil Red O showed a remarkable accumulation of lipid droplets by 20-d post-differentiation and a plateau at 26 - 30 day. Treatment with 100 μM T1AM for 6 h increased the liberation of free fatty acids (FFAs) and glycerol (P < 0.05) detected in the culture media. However, this stimulatory effect was significantly suppressed by ATGListatin, an inhibitor of adipose triglyceride lipase (ATGL), suggesting that ATGL plays a rate-limiting role in triglyceride (TG) turnover. To understand the lipolytic mechanism, immunoblotting and confocal image analyses of the T1AM-treated and control groups were conducted. The elevated lipolysis was accompanied by increases in the phosphorylation of adenosine monophosphate-activated protein kinase (p-AMPK), nuclear localization of forkhead box O1 (FoxO1), and expression of monoacylglycerol lipase (MGL) protein (P < 0.05). Finally, the treated cells exhibited downregulated expression of acetyl-CoA carboxylase (ACC) relative to p-ACC and increased protein expression of carnitine palmitoyltransferase 1 (CPT1) (P < 0.05). Taken together, T1AM showed lipolytic potency via activation of the AMPK/FoxO1/ATGL/MGL axis for decomposing TGs to FFAs and glycerol and of the AMPK/ACC/CPT1 pathway in facilitating the mobilization of FFAs into the mitochondria, highlighting its therapeutic potential for the treatment of obesity.

Administration of warfarin accelerates the recovery in ischemia/reperfusion-induced acute pancreatitis.

Acute pancreatitis is associated with activation of coagulation and there is a close relationship between coagulation and the severity of this disease. Administration of anticoagulants such as heparin or acenocoumarol has shown to reduce the severity of acute pancreatitis and accelerate the recovery. The aim of the current study was to determine the impact of warfarin administration on the course of ischemia/reperfusion-induced acute pancreatitis. Acute pancreatitis was induced in rats by pancreatic ischemia followed by reperfusion. Vehicle (1 ml/dose) or warfarin (45, 90 or 180 μg/kg/dose in 1 ml of vehicle) were administered intragastrically once a day. The first dose of warfarin was given 24 h after the start of pancreatic reperfusion. The severity of acute pancreatitis was assessed 2, 5, 9 and 14 days after the beginning of pancreatic reperfusion. Treatment with warfarin reduces pancreatic damage and accelerates recovery in histological examination and this effect is accompanied by a faster reduction in serum activity of pancreatic digestive enzymes, lipase and amylase. In addition, warfarin led to an earlier decrease in serum concentration of pro-inflammatory interleukin-1β and plasma level of D-dimer. These effects were associated with an improvement of pancreatic blood flow. We conclude that warfarin exhibits a therapeutic effect in acute pancreatitis evoked by pancreatic ischemia followed by reperfusion.

Immobilization of Candida antarctica Lipase on Nanomaterials and Investigation of the Enzyme Activity and Enantioselectivity.

This study defines the lipase immobilization protocol and enzymatic kinetic resolution of 1-phenyl ethanol with the use of immobilized lipases (LI) as a biocatalyst. Commercially available lipase Candida antarctica B (Cal-B) was immobilized onto graphene oxide (GO), iron oxide (Fe3O4) nanoparticles, and graphene oxide/iron oxide (GO/Fe3O4) nanocomposites. Characterization of pure and enzyme-loaded supports was carried out by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The influences of pH, temperature, immobilization time, crosslinker concentration, glutaraldehyde (GLA), epichlorohydrin (EPH), and surfactant concentrations (Tween 80 and Triton X-100) on the catalytic activity were evaluated for these three immobilized biocatalysts. The highest immobilized enzyme activities were 15.03U/mg, 14.72U/mg, and 13.56U/mg for GO-GLA-CalB, Fe3O4-GLA-CalB, and GO/Fe3O4-GLA-CalB, respectively. Moreover, enantioselectivity and reusability of these immobilized lipases were compared for the kinetic resolution of 1-phenyl ethanol, using toluene as organic solvent and vinyl acetate as acyl donor. The highest values of enantiomeric excess (ees = 99%), enantioselectivity (E = 507.74), and conversion (c = 50.73%) were obtained by using lipase immobilized onto graphene oxide (GO-GLA-CalB). It was obtained that this enzymatic process may be repeated five times without important loss of enantioselectivity.

Diagnostic value of hematological parameters in acute pancreatitis.

Acute pancreatitis (AP) is an inflammatory disease with rapid onset and rapid progression. In severe cases, it can cause systemic inflammatory response syndrome (SIRS), multiple organ failure (POF) and death. In order to explore the effective index of early diagnosis of AP, we have detected the levels of serum lipase (LPS), serum amylase (S-AMY) and C-reactive protein (CRP). Meanwhile, cost evaluation was performed on these biochemical parameters for AP patients. In this study, 212 patients were admitted with acute abdominal pain, divided into AP group (n=107) and non-AP group (n=105), including cholelithiasis (n=8), intestinal obstruction (n=34), acute cholangitis (n=14), acute cholecystitis (n=20), acute appendicitis (n=20) and pancreatic cancer (n=9). Demographic data and laboratory examination results were collected, the sensitivity and specificity of LPS, S-AMY and CRP in the diagnosis of AP were calculated respectively, as well as the costs of single or multiple tests were evaluated. The serum level of S-AMY and LPS in AP group were significantly higher than those in nonAP group (P<0.01), The serum level of CRP in AP group was higher than that in non-AP group (P<0.05). When the critical value of the normal reference value is three times as the critical value, the sensitivity and specificity of the LPS in diagnosing AP were 91.6% and 90.5%, S-AMY was 70.1% and 91.4%. And CRP was 59.8% and 56.2%, respectively. Compared with the trend of serum LPS expression, the expression trend of S-AMY was positively correlated (r=0.81), while there was no correlation with the trend of CRP expression. The ability of LPS to diagnose AP is significantly better than that of LPS + CRP, as well as the combined detection of LPS + CRP + S-AMY, which can be used as the first choice for laboratory examination of AP.

Aspergillus nidulans: A Potential Resource of the Production of the Native and Heterologous Enzymes for Industrial Applications.

Aspergillus nidulans is a filamentous fungus that is a potential resource for industrial enzymes. It is a versatile fungal cell factory that can synthesize various industrial enzymes such as cellulases, β-glucosidases, hemicellulases, laccases, lipases, proteases, β-galactosidases, tannases, keratinase, cutinases, and aryl alcohol oxidase. A. nidulans has shown the potential to utilize low-cost substrates such as wheat bran, rice straw, sugarcane bagasse, rice bran, coir pith, black gram residue, and chicken feathers to produce enzymes cost-effectively. A. nidulans has also been known as a model organism for the production of heterologous enzymes. Several studies reported genetically engineered strains of A. nidulans for the production of different enzymes. Native as well as heterologous enzymes of A. nidulans have been employed for various industrial processes.

Malassezia species may play potential roles in the pathogenesis of meibomian gland dysfunction

Meibomian gland dysfunction (MGD) is the most common cause of dry eye disease (DED). Although many factors, such as aging, androgen deficiency, bacterial colonization and drug toxicity have been demonstrated to be associated with MGD, its pathogenesis is not well understood and definite therapies are lacking. Meibomian gland is the largest lipid-secreting gland of human and is the counterpart of sebaceous gland in the eyelid. The lipophilic yeast Malassezia species (spp) habitats in sebaceous gland and is generally considered to play pathogenic roles in seborrheic dermatitis. Several mechanisms have been illuminated, including secretion of lipases, production of toxic metabolites and generation of reactive oxidative species. Anti-fungal therapy is beneficial for patients with seborrheic dermatitis. So far, no previous studies have investigated the link between Malassezia spp and MGD. But there are reports which demonstrate increased prevalence of both high delivery and obstructive MGD in patients with seborrheic dermatitis. Malassezia spp is also found to be associated with anterior blepharitis, the seborrheic inflammation of the other counterpart of sebaceous gland in the eyelid-the Zeis gland. Based on the pathogenic role of Malassezia spp and its highly lipophilic characteristic, we hypothesize that Malassezia spp may also habitat in meibomian gland and play potential pathogenic roles in MGD. Anti-fungal treatment with 2% ketoconazole cream may be potential therapy for patients with MGD. If the hypothesis can be confirmed on patients, it can provide a novel insight of the pathogenesis of MGD and hopefully trigger further investigation into the relationship between microbiota colonization and the function of meibomian gland.

Inhibition of fatty acid oxidation induced by up-regulation of miR-124 and miR-205 during exposure of largemouth bass (Micropterus salmoides) to acute hypoxia

With increased breeding density, the possibility of hypoxia increases. This study simulated the hypoxic environment (1.2 ± 0.2 mg / L) that may occur within 24 h of aquaculture to stress largemouth bass (Micropterus salmoides). The effects of this environment on related enzymes and genes were examined to explore the effects of hypoxia on lipid metabolism in the liver. Hypoxic stress increased liver triglyceride and non-esterified fatty acid content, and increased lipase (LPS) and lipoprotein lipase (LPL) activities related to fat mobilization. Hypoxia stress also significantly increased the expression levels of genes involved in fatty acid activation and fatty acid transport, including hormone-sensitive triglyceride lipase (HSL), solute carrier family member 27 member 6 (SLC27A6), peroxisomal proliferation activated receptor alpha (PPARA,) and acyl-CoA synthase long-chain family 4 (ACSL4). However, hypoxia stress significantly reduced the expression level of the carnitine palmitoyltransferase 1 (CPT-1) gene, with a downward trend of enzyme activity. The decreased level of CPT-1 was explained by negative regulation by miR-124 and miR-205, as measured by quantitative polymerase chain reaction and dual-luciferase reporter assays. Overall, acute hypoxic stress enhanced lipid mobilization, fatty acid activation, and fatty acid transport, but inhibited fatty acid oxidation by miR-124 and miR-205 down-regulation of CPT-1 expression. These findings provide new insights into the regulation of lipid metabolism in fish under hypoxic stress.

Necrotizing Pancreatitis in a 12 Year Male Presenting in Diabetic Ketoacidosis

Introduction: Vomiting and abdominal pain are overlapping clinical symptoms of diabetic ketoacidosis (DKA) and acute pancreatitis. Pancreatic enzymes are not routinely measured during the initial evaluation of DKA, though modest elevation of serum lipase is common. Acute pancreatitis is reported in about 2% of patients with DKA, and typically resolves with conservative management. Necrotizing pancreatitis (NP) is exceedingly rare in children. We are aware of only one other reported pediatric case of DKA associated NP. Case Presentation: A 12-year-old Hispanic male with obesity and bipolar disorder, who recently discontinued valproic acid …

EVALUATION OF ENZYMATIC HYDROLYSIS APPLIED TO FISH BY-PRODUCT OIL THROUGH CHEMICAL PARAMETERS

Large amounts of fish waste are produced by the fish processing plants. This waste could be used to obtain high value-added products, such as long chain polyunsaturated fatty acids. Thus, the aim of this work was to evaluate the enzymatic hydrolysis of low commercial value crude fish oil through chemical parameters. Crude fish oil was obtained from mixed fishmeal production and was chemically refined. Candida rugosa lipase AY Amano 30 was utilized to catalyze the enzymatic hydrolysis. The acidity index, iodine value, saponification index and peroxide value were used to characterize the samples studied. The chemical refining process yielded 62.75% and improved the quality of crude fish oil by reducing the acidity index around 91%. The best results of hydrolysis degree (23.45%) and iodine value (120 g I2 g-1) were obtained at 45oC after 6 h of lipase action. The iodine value of crude oil was not affected by processing, indicating that the nutritional quality was preserved in the refined oil. Despite the hydrolysis process showed good results, it was not sufficient to concentrate the unsaturated fatty acids of refined oil, as indicated by the iodine value.

The role of melatonin in alleviating the postharvest browning of lotus seeds through energy metabolism and membrane lipid metabolism

Abstract To investigate the underlying mechanism of melatonin (MT) involvement in the browning of lotus pods and seeds, the samples were immersed in 100 μmol L−1 MT and 10 μmol L−1 luzindole, a nonselective MT1/MT2 receptor antagonist. The energy and membrane lipid metabolisms of lotus seeds during 8 d at 25 ± 1 °C were evaluated. The results indicated that MT treatment suppressed the browning of lotus seeds through enhancing the endogenous MT content, while luzindole demonstrated an opposite effect. Compared with the control, the MT treatment ensured the energy status of lotus seeds, as the ATP content and energy charge were promoted. The activities of cytochrome C oxidase (CCO), succinate dehydrogenase (SDH), and ATPases were enhanced by the treatment, which might contributued to the ATP production. Additionally, the cell membrane integrity of lotus seeds was maintained by MT treatment through reducing the cell membrane permeability, O2 ¯ production rate, and malondialdehyde and H2O2 contents, as well as enhancing the unsaturated-to-saturated fatty acids ratio, which could be explained by inhibited lipoxygenase (LOX), lipase (LPS) and phospholipase D (PLD) activities. Thus, the sufficient energy supply and normal cell membrane function may be responsible for the attenuated browning of lotus pods and seeds by MT treatment.

Effect of acute exposure to ammonia and BFT alterations on Rhynchocypris lagowski: Digestive enzyme, inflammation response, oxidative stress and immunological parameters

Biofloc technology (BFT) is a new green culture technology that is intended not merely to eradicate nitrogenous residues but also enhance immunity and antioxidant activity in aquatic animals. A 56-day feeding trial and a 96 h ammonia challenge test were implemented to evaluate the effect of acute exposure to ammonia and BFT alterations on Rhynchocypris lagowski: digestive enzyme, inflammation response, oxidative stress and immunological parameters in zero water exchange tanks. According to the differences of C/N ratios, the experiment was divided into four groups: C/N 10.8:1 (control group), C/N 15:1, C/N 20: 1 and C/N 25:1. The results provided evidence that weight gain rate (WGR), specific growth rate (SGR) and protein efficiency ratio (PER) were significantly elevated in C/N 20, while food conversion rate (FCR) was considerably decreased (P < 0.05) compared to the control. Significant increases in digestive enzyme amylase (AMS), lipase (LPS), protease (PRS) and cellulase (CES) activity; Immune enzyme complement C3, complement C4, Nitric Oxide Synthase (NOS) and immunoglobulin M (IgM) activity; Serum biochemical lysozyme (LSZ), glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT) and alkaline phosphatase (AKP) activity; Inflammation TNF-α, IL-1β, IL-2, IL-6 of R. lagowskis were found in the C/N 20 group after a 56-day feeding trial and a challenging trial (P < 0.05). Comparing the antioxidant capacity of R. lagowski in gills, brains and spleen of juveniles from the four experimental groups, the activity of superoxide dismutase (SOD), total antioxidant capacity (T-AOC), catalase (CAT) activity and glutathion reductases (GR) activity of juveniles in the C/N 20 group were significant higher (P < 0.05), and the content of malondialdehyde (MDA) was considerably lower than that in the control. Overall, these findings suggest that BFT not only can enhance R. lagowski growth performance, digestive enzyme activity, and strengthen antioxidant status but also upgrade immune response, improve the ability of resistance to ammonia stress.

Ocean acidification, hypoxia and warming impair digestive parameters of marine mussels

Global change and anthropogenic activities have driven marine environment changes dramatically during the past century, and hypoxia, acidification and warming have received much attention recently. Yet, the interactive effects among these stressors on marine organisms are extremely complex and not accurately clarified. Here, we evaluated the combined effects of low dissolved oxygen (DO), low pH and warming on the digestive enzyme activities of the mussel Mytilus coruscus. In this experiment, mussels were exposed to eight treatments, including two degrees of pH (8.1, 7.7), DO (6, 2 mg/l) and temperature (30 °C and 20 °C) for 30 days. Amylase (AMS), lipase (LPS), trypsin (TRY), trehalase (TREH) and lysozyme (LZM) activities were measured in the digestive glands of mussels. All the tested stress conditions showed significant effects on the enzymatic activities. AMS, LPS, TRY, TREH showed throughout decreased trend in their activities due to low pH, low DO, increased temperature and different combinations of these three stressors with time but LZM showed increased and then decreased trend in their activities. Hypoxia and warming showed almost similar effects on the enzymatic activities. PCA showed a positive correlation among all measured biochemical parameters. Therefore, the fitness of mussel is likely impaired by such marine environmental changes and their population may be affected under the global change scenarios.

Waste Cooking Oil for Wax Esters Synthesis Using Candida Rugosa Lipase Immobilized on Fe3o4@oa Nanoparticles

Wax ester is an important skin conditioning agent derived from the esterification of fatty acids with alcohols. It is widely used in cosmetic as it has a composition similar to that of natural skin lipids. This study presents the synthesis of wax esters from hydrolyzed WCO in presence of cetyl alcohol and Candida rugosa lipase immobilized on Fe3O4@OA. The effects of the reaction time and cycles of reuse were investigated. The wax ester conversion has been monitored for 24 h. High conversion of ~ 89.3 % was observed already at 12 hours of synthesis. No significant reduction, during four cycles of use, of the lipase activity occurs.

Effects of dietary Chinese herbal medicines mixture on feeding attraction activity, growth performance, nonspecific immunity and digestive enzyme activity of Japanese seabass (Lateolabrax japonicus)

The purpose of this study was to evaluate the effects of Chinese herbal medicines mixture (CHMM: consisted of asafoetida Ferula sinkiangensis K. M. Shen, Medicago falcata L.and Allium sativum) on feeding attraction activity (FAA), growth performance, nonspecific immunity and digestive enzyme activity of juvenile Japanese seabass (Lateolabrax japonicus). Six diets containing 0, 5, 10, 15, 20 and 25 g/kg CHMM were designed for the luring and feeding experiment. A clear attractive trend of the CHMM on Japanese seabass was found after a 5-day luring trial. The 28-day feeding experimental results indicated that dietary CHMM significantly influenced weight gain (WG) and specific growth rate (SGR) of fish (P < 0.05), with the highest WG and SGR observed in fish fed 20 g/kg CHMM diet. The feed conversion ratio (FCR) of each treatment group was significantly reduced by the CHMM. The body crude lipid content was significantly increased except for the 15 g/kg group (P < 0.05). The supplementation of CHMM could significantly increase the activity of lysozyme (LZM) and total superoxide dismutase (T-SOD) in serum with the highest values observed in the 20 mg/kg group while the content of total protein (TP) was increased significantly in the fish fed the diet with 10−15 g/kg CHMM (P < 0.05). Digestive enzymes including lipase (LPS) and trypsin activities were obviously affected by the CHMM and reached the highest among all groups at 20 g/kg diet. Regression analyse of the FAA, FCR, WG, SGR, TP, LZM, T-SOD, LPS and trypsin were performed, showing the optimal additional amount was 12.75, 15.09, 20.14, 20.00, 16.13, 18.31, 17.33, 21.38 and 21.17 g/kg, respectively. Comprehensive consideration of the current experimental results and the regression analyses, we suggested the additive suitable dosage of the CHMM was 20 g/kg diet.

RNA interference provides insights into the multi-functional profiles of Es-MSTN gene in Eriocheir sinensis

Myostatin (MSTN) is a negative regulation factor involved in skeletal muscle growth and development in vertebrates. In order to understand the multi-functional roles of MSTN in crustaceans, we assessed the molting / growth characters, analyzed the tissues composition and investigated the expression levels of lipid metabolism and immune related genes in Chinese mitten crab (Eriocheir sinensis) after injection of Es-MSTN dsRNA during one molt cycle of 49 days. We found the RNAi group displayed shorter molting interval, higher specific growth rate, and lower hepatosomatic index compared with the control group, evidencing MSTN may also be a negative regulator of muscle growth and development in E. sinensis. In the RNAi group, the expression levels were upregulated for lipid metabolism-related genes of pancreatic lipase (LP), carnitine palmitoyl transferases 1β (CPT1β) and fatty acid-binding protein 3 (FABP3) in muscles, but were downregulated for these three genes and fatty acid-binding protein 9 (FABP9) in hepatopancreas. Meanwhile, the expression levels were all upregulated for immune-related genes of prophenoloxidase (PHE), anti-lipopolysaccharide factor (ALF), Lectin H (LecH), and prophenoloxidase-activating factor (PPAF) in both muscle and hepatopancreas in the RNAi group. Further tissue composition analysis showed that there were no significant differences in amino acid composition between the RNAi and control groups in muscle and hepatopancreas, but most of significant differences in fatty acid composition were detected between the two groups in both muscle and hepatopancreas. This study demonstrated that Es-MSTN is a vital muscle growth inhibition factor and displayed diverse function in participating in energy metabolism and immune response in E. sinensis.