ABSTRACT
Hepatic fibrosis is a repair process of the liver in response to various chronic injuries. The unbalanced proliferation and decomposition of fibrous tissue in the liver causes the excessive deposition of fibrous connective tissue in the liver. Hepatic fibrosis is a common intermediate link in a variety of chronic liver diseases. In this pathological process, the interaction between cells and cytokines leads to the disorder of liver extracellular matrix metabolism, which results in excessive deposition of fibrous tissue in the liver, and eventually causes liver fibrosis. After continuous deterioration, it would gradually develop into liver cirrhosis and even liver cancer. Because liver fibrosis and liver cirrhosis can be reversed in the early stage, it is very important to control the reversible process of liver fibrosis for the prevention and treatment of liver cirrhosis and liver cancer. Cordyceps, as one of valuable medicinal fungi in China, has been given widespread attention from scientific workers, with broad pharmacological actions. Cordyceps polysaccharide is the highest content of bioactive substances in Cordyceps. Recent studies have found that it has an anti-hepatic fibrosis effect. With the application of molecular biology technology, researches on the anti-liver fibrosis mechanism of traditional Chinese medicine at home and abroad have been gradually deepened into the cellular and molecular levels. This paper will investigate the preventive effect of Cordyceps polysaccharide in terms of cell basis, cytokines, collagenase and lipid peroxidation level that are related to liver fibrosis, so as to clarify the specific action mechanism on anti-hepatic fibrosis, and provide a reference for the development of anti-hepatic fibrosis drugs.
ABSTRACT
Aim To investigate the protective effect of Qi ZhiXiaoke granules ( QZXK ) on nerve injury using zebrafish and nerve cell injury models. Methods The nerve injury model was established using wild zebrafish AB line, 72 hours after fertilization treated with 1-methyl-4-phenyl-1 , 2 , 3 , 6-four pyridine ( MPTP ) .Then QZXK of different doses were administered for three days,and the trajectory of the zebrafish behavior was recorded and analyzed. Neuroblastoma PC12 cells were incubated with different concentrations of QZXK and MPTP,and the cell viability of PC12 cells was de-tected by MTT. The mitochondrial membrane potential and expression of apoptosis related protein Caspase3 were measured by kits. Results Compared with con-trol group,MPTP reduced the movement distance of ze-brafish,and with the increase of concentration, QZXK promoted the movement distance and reversed the swimming behavior abnormality of zebrafish. Compared with control group, QZXK could inhibit the apoptosis induced by MPTP and promote the cell viability of PC12 cells with MPTP. QZXK improved the membranepotential and decreased the expression of Caspase3 . Conclusions QZXK exerts neuroprotective effect in the process of nerve injury induced by MPTP. The mechanism may be related with inhibiting apoptosis of neural cells. These experiment provides experimental and theoretical foundation for QZXK promoting cogni-tive function.
ABSTRACT
L-arabinose isomerase (L-AI) can isomerize L-arabinose and D-galactose into L-ribulose and D-tagatose, respectively, which is currently the most effective biological catalyst for D-tagatose production. The crystal structure of L-AI has been solved recently and its gene has been cloned, sequenced and overex- pressed. L-AI improved by protein engineering will be the dominant enzyme for industrial production of D-tagatose. This paper reviewed researches on protein structure and function, properties and application in D-tagatose production of L-AI, and the long-term potential development of L-AI was prospected.
ABSTRACT
Thermostable L-arabinose isomerase (L-AI) is the most potential enzyme for the biological production of D-tagatose from D-galactose, a novel functional factor. Gene araA encoding the L-arabinose isomerase from Bacillus stearothermophilis IAM 11001 was cloned and expressed in Escherichia coli. The araA gene of 1491 bp has 95% identity with L-AI from Thermus sp. IM6501. The GenBank accession number for the nucleotide sequence of this araA gene determined in this work is EU394214.The bacterium was induced by IPTG and analyzed by SDS-PAGE, approximately 59 kDa exogenous protein was observed on the SDS-PAGE. The recombinant L-AI was purified to electrophoretical homogeneity with affinity chromatography, and the activity of recombinant L-AI was also studied. The bioconversion rate of D-galactose to D-tagatose reached 39.4% after 24h whole cell reaction.