大曲酶系研究的回顾与展望

对大曲中酶类的组成、几种主要酶类的研究现状作了全面分析。列举了浓香型大曲中部份酶的含量。作者认为 ,应逐步弄清大曲质量指标与实际生产应用的关系 ,加强大曲质量体系建立的研究 ,强化大曲中酯化酶、酸性蛋白酶。

Omega-3 fatty acids for the treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease （NAFLD） has been recognized as a major health burden. It is the most important cause of chronic liver disease and a major in- dependent cardiovascular risk factor. Lacking a definite treatment for NAFLD, a specific diet and an increase in physical activity represent the most commonly used therapeutic approaches. In this review, major literature data about the use of omega-3 polyunsaturated fatty ac- ids （n-3 PUFAs） as a potential treatment of NAFLD have been described, n-3 PUFAs, besides having a beneficial impact on most of the cardio-metabolic risk factors （hy- pertension, hyperlipidemia, endothelial dysfunction and atherosclerosis） by regulating gene transcription factors [i.e., peroxisome proliferator-activated receptor （PPAR） cz, PPARy, sterol regulatory element-binding protein-i, carbohydrate responsive element-binding protein], im- pacts both lipid metabolism and on insulin sensitivity. In addition to an enhancement of hepatic beta oxidation and a decrease of the endogenous lipid production, n-3 PUFAs are able to determine a significant reduction of the expression of pro-inflammatory molecules （tumor necrosis factor-~ and interleukin-6） and of oxygen reac- tive species. Further strengthening the results of the in vitro studies, both animal models and human interven- tion trials, showed a beneficial effect of n-3 PUFAs on the severity of NAFLD as expressed by laboratory pa- rameters and imaging measurements. Despite available results provided encouraging data about the efficacy of n-3 PUFAs as a treatment of NAFLD in humans, well- designed randomized controlled trials of adequate size and duration, with histological endpoints, are needed to assess the long-term safety and efficacy of PUFA, as well as other therapies, for the treatment of NAFLD and non-alcoholic steatohepatitis patients. It is worthwhile to consider that n-3 PUFAs cannot be synthesized by the human body and must be derived from exogenous sources （fish oil, flaxseeds, olive oil） which are typical foods of the Mediterranean diet, known for its beneficial effects in preventing obesity, diabetes and, in turn, cardiovascular events. According to these data, it is important to consider that most of the beneficial effects of n-3 PUFAs can also be obtained by an equilibrate nutrition program.

Production of Amylase from Saccharomyces diastaticus sp. and Hydrolysis of Cassava Pulps for Alcohol Production

Amylolytic enzymes are currently investigated to improve industrial processes of starch degradation. Saccharomyces diastaticus 2047 isolated from cassava waste showed amylase and glucoamylase production, using starch medium, and the highest rate was obtained in the initial growth phase, after incubation for 24 h at pH 5.5. Maximum amylase and glucoamylase activities （483.62 U mg^-1 protein and 290.85 U mg^-1 protein） were obtained at pH 5.5. The isolated enzymes exhibited thermostable properties as indicated by retention of 100% of residual activity at 55 ℃ for 45 min with total inhibition at 100 ℃. Extracellular enzyme from S diastaticus 2047 was partially purified by fractionated precipitation with ammonium sulphate. After 40% saturation produced 2,197.00 and 1,192.83 U/mg protein, and yield was 40% with purification 4.54 and 4.1 fold, respectively. This study presents feasibility on ethanol production from cassava pulps pretreated with diluted sulfuric acid by simultaneous saccharification and fermentation （SSF） with S. diastaticus 2047. The results indicated that the culture was able to produce ethanol with high yield without amylolytic enzyme adding by using cassava pulps pretreated with distilled water at 135 ℃ under pressure of 15 lb/inch^2 to produce ethanol yield as high as the cassava pulps pretreated with diluted sulfuric acid under the same condition. This suggests that S diastaticus with enzyme produced has potential for industrial applications.

Techniques Optimization of Combined Enzymatic Hydrolysis on Brewers＇ Spent Grain from Novozymes

Purpose： To extract protein, decrease the cellulose and facilitate the digestion and absorption of brewers＇ spent grain by animal. Topic： Discuss and optimize the hydrolysis conditions of the combined enzymatic hydrolysis by Novozymes. Method： The fresh brewers＇ spent grain was firstly dried, smashed and sifted. Then as indicators of the protein extraction rate in the enzyme solution and the content of cellulose in the index, the parameters of enzymatic hydrolysis, such as the solid-liquid ratio, reaction temperature, pH, enzyme dosage and reaction time, were investigated in detailed. After hydrolysis, the brewers＇ spent grain was put in the boiling water bath for inactivation for 15 minutes, and centrifuged, the supernatants were volume to 100 mL and the protein content was measured. After the precipitate was dried, the cellulose content was also measured. Achievements： The optimized conditions were with temperature of 50 ℃, pH 6.5, enzyme amount of 30 mg for Novozymes enzyme and 2.5 h for reaction time. Under these conditions, the protein extraction rate in the enzyme reaction reached 41.82%, and the cellulose content reached 13.90%, the degradation rate of cellulose was 18.86%.

Signal transduction mechanism of TRB3 in rats with non-alcoholic fatty liver disease

AIM： To evaluate the possible role of Tribble 3 （TRB3） in a rat model of non-alcoholic fatty liver disease （NAFLD） and its signal transduction mechanism.METHODS： Thirty Sprague-Dawley rats were randomized into three groups： normal control group, non-alcoholic fatty liver group A （fed on a high-fat diet for 8 wk） and group B （fed on a high-fat diet for 16 wk）. To determine the degree of hepatic steatosis in rats of each group, livers were stained with hematoxylin and eosin, and evaluated; real-time fluorescent quantitative reverse transcriptase-polymerase chain reaction was performed to measure the expression levels of TRI33 mRNA, and Western blotting analysis was done to determine the expression levels of protein kinase B （Akt） and phosphorylated protein kinase B （p-Akt-Thr308, p-Akt-Ser473）.RESULTS： Hepatic steatosis was evident in both NAFLD groups： mild to moderate hepatic steatosis occurred in group A, mainly as mild steatosis.Moderate to severe hepatic steatosis occurred in group B, mainly as severe steatosis. The expression level of TRB3 mRNA in group B was significantly higher than in the control group （122.28 ± 95.37 vs 3.06 ± 2.33,P = 0.002） and group A （122.28 ± 95.37 vs 5.77 ± 4.20,P = 0.001）. There was no significant difference in the expression levels of Akt （1.03 ± 0.53 vs 1.12 ± 0.77,P = 0.729） and p-Akt-Thr308 （0.82 ± 0.45 vs 0.92 ± 0.38, P = 0.592） between group A and the control group. The expression level of Akt and p-Akt-Thr308 in group B was significantly lower than in group A （Akt 0.41 ± 0.16 vs 1.12 ± 0.77, P = 0.008; p-Akt-Thr308 0.47 ± 0.19 vs 0.82 ± 0.45, P = 0.036） and the control group （Akt 0.41 ± 0.16 vs 1.03 ± 0.53, P = 0.018;p-Akt-Thr308 0.47 ± 0.19 vs 0.92 ± 0.38, P = 0.010）.The expression level of p-Akt-Ser473 in group A was significantly higher than in group B （1.48 ± 0.50 vs 0.81± 0.39, P = 0.041） as well as the control group （1.48 ± 0.50 vs 0.45 ± 0.26, P = 0.003）.CONCLUSION： TRB3 blocks insulin signaling by inhibiting Akt activation, which contributes to insulin resistance. It may be an important factor in the occurrence and development of NAFLD.

Regulatory effects of the combination of berberine and ginsenoside Rb1 on high-fat diet-induced nonalcoholic fatty liver disease via AMPK pathway and improved pharmacokinetics

Objective： We evaluated the protective effects of berberine （BBR） combined with ginsenoside Rb1 （G-Rb1） on high-fatdiet （HFD）-induced nonalcoholic fatty liver disease （NAFLD） in rats and futher investigated the underlying mechanisms.Methods： Rats were fed an HFD for 6 weeks and then randomly divided into four groups and treated with BBR （50mg/kg）, G-Rb1 （100 mg/kg）, BBR （50 mg/kg） ＋ G-Rb1 （100 mg/kg）, or fenofibrate （40 mg/kg）. Histological examinationof liver tissue was performed. In human hepatocellular carcinoma cells HepG2, protein expression of AMP-activatedprotein kinase （AMPK） and acetyl-CoA carboxylase was detected by western blotting, and the mRNA expression ofcarnitine palmitoyl transferase 1 and 3-hydroxy-3-methyl glutaryl coenzyme A reductase was detected by quantitativePCR. Pharmacokinetic assessments included analysis of bioavailability of BBR and G-Rb1 in vivo and G-Rb1 metabolismby intestinal bacteria in vitro. Results： Compared to the single-use group, BBR combined with G-Rb1 significantlyameliorated hepatic fat accumulation in HFD-induced obese rats, as demonstrated by reduced hepatic triglyceridecontent, and histological evaluation of liver sections. Activation of hepatic AMPK and phosphorylation of acetyl-CoAcarboxylase were significantly elevated in hepatocytes treated with both BBR and G-Rb1. Consistent with the activationof AMPK, the mRNA expression of carnitine palmitoyl transferase 1 was stimulated, while the mRNA expression of3-hydroxy-3-methyl glutaryl coenzyme A reductase was suppressed. Pharmacokinetic analysis revealed that BBRincreased the bioavailability of G-Rb1 in Sprague-Dawley rats. Additionally, BBR prevented degradation of G-Rb1 infecal solution in vitro. Conclusion： BBR combined with G-Rb1 improved NAFLD through the AMPK signaling pathway,and BBR enhanced G-Rb1 bioavailability via promoting the intestinal absorption of G-Rb1. This combination may be auseful therapeutic agent for NAFLD.

Correlations Between Polymorphisms of Extracellular Superoxide Dismutase, Aldehyde Dehydrogenase-2 Genes, as Well as Drinking Behavior and Pancreatic Cancer

Objective To investigate the correlation between drinking behavior combined with polymorphisms of extracellular superoxide dismutase （EC-SOD） and aldehyde dehydrogenase-2 （ALDH2） genes and pancreatic cancer. Methods The genetic polymorphisms of EC-SOD and ALDH2 were analyzed by polymerase chain reaction restriction fragment length polymorphism in the peripheral blood leukocytes obtained from 680 pancreatic cancer cases and 680 non-cancer controls. Subsequently the frequency of genotype was compared between the pancreatic cancer patients and the healthy controls.The relationship of drinking with pancreatic cancer was analyzed. Results The frequencies of EC-SOD （C/G） and ALDH2 variant genotypes were 37.35% and 68.82% respectively in the pancreatic cancer cases, and were significantly higher than those in the healthy controls （21.03% and 44.56%, all P〈0.01）. People who carried EC-SOD （C/G） （0R=2.24, 95% C1= 1.81-4.03, P〈0.01） or ALDH2 variant genotypes （OR=2.75, 95% CI=1.92-4.47, P〈0.01） had a high risk to develop pancreatic cancer. Those who carried EC-SOD （C/G） genotype combined with ALDH2 variant genotype had a high risk for pancreatic cancer （29.56% vs. 6.76%, 0R=7.69, 95% CI=3.58-10.51, P〈0.01）. The drinking rate of the pancreatic cancer group （64.12%） was significantly higher than that of the control group （40.15%; OR=2.66, 95% CI=1.30-4.42, P〈0.01）. An interaction between drinking and EC-SOD （C/G）/ALDH2 variant genotypes increased the risk of occurrence of pancreatic cancer （OR=25.00, 95% CI= 11.87-35.64, P〈0.01）. Conclusion EC-SOD （C/G）, ALDH2 variant genotypes and drinking might be the risk factors of pancreatic cancer.