Dioscin Inhibits Ubiquitin-Proteasome System in Cancer Cells / 肿瘤防治研究

Objective To explore the antitumor small molecules targeting the ubiquitin–proteasome system (UPS) on the basis of active molecules from traditional Chinese medicine. Methods UbG76V-GFP stably expressing cell line was constructed to screen novel small molecule inhibitors targeting UPS. The fluorogenic substrates of Suc-LLVY-AMC, Z-LLE-AMC, and Boc-LRR-AMC were used to assess the effect of dioscin on the 20S proteasome hydrolase activity. The Ub-AMC substrate was used to evaluate the effect of dioscin on the intracellular deubiquitinating enzyme activity. Western blot was used to detect the effect of dioscin on intracellular ubiquitination levels. CCK-8 and colony formation assays were used to detect the inhibitory effect of dioscin on the tumor cell proliferation. Results Dioscin is a UPS inhibitor discovered through the UbG76V-GFP reporter system. It enhances intracellular ubiquitination and inhibits tumor cell proliferation and colony formation by targeting deubiquitinating enzymes. Conclusion Dioscin could significantly inhibit tumor cell proliferation by targeting ubiquitin–proteasome.

Systematic Identification of the Main Constituents from Agrimonia pilosa Ledeb. and Their Metabolites in Rats using HPLC-Q-TOF-MS/MS.

Agrimonia pilosa is a perennial herbaceous flowering plant, commonly known as agrimony or hairy agrimony. The dried aerial parts of this species have been widely used for the treatment of acute diarrhea, hemostasis, and other inflammation-related diseases. However, information on the in vivo metabolism of A. pilosa constituents is limited. In this study, the phytochemical profile of A. pilosa was investigated using HPLC-Q-TOF-MS/MS combined with a nontargeted diagnostic ion network analysis strategy. An information-dependent acquisition method with multiple filters was utilized to screen possible prototypes and metabolites in complex biological matrices. Furthermore, various data-processing techniques were applied to analyze possible prototypes and their metabolites in rat plasma, feces, and urine following oral administration of A. pilosa extract. A total of 62 compounds, which belonged to five main structural classes (21 phenols, 22 flavonoids, 6 coumarins, 3 triterpenes, and 10 organic acids), were tentatively identified in A. pilosa. In addition, using our proposed stepwise method, 32 prototypes and 69 metabolites were detected in rat plasma, feces, and urine. The main metabolic pathways after the oral administration of A. pilosa extract were revealed to include methylation, dihydroxylation, demethylation, hydrolysis, sulfation, and glucuronidation. This comprehensive in vivo and in vitro identification of the possible active components in A. pilosa could provide a basis for understanding its various pharmacological activities.

THE EFFECTS OF VARIOUS AMOUNTS OF ASCORBIC ACID INTAKE ON THE CHOLESTEROL CONTENTS IN SERUM AND LIVER AND THE MORPHOLOGICAL CHANGES IN ARTERIES OF GUINEA PIGS / 营养学报

Male guinea pigs were placed on ordinary or high lipid diet for 30-36 weeks with various amounts of ascorbic acid (Vc) intake. The daily dose of low level intake was 0.7-1.2mg. The normal one was 2.5-5mg. The high dose was 30-45mg. The various amounts of Vc intake did not affect the cholesterol contents in serum and liver. The animals fed low level Vc were without "overt signs of deficiency, but morphological changes of aorta were developed in these animals either on ordinary or high lipid diet. On high lipid diet, the pathological changes of the vessels (aorta and arteriols in cardiac muscles) of animals fed low level of Vc were more severe than those of animals fed normal level, and those of animals fed high dose were the least severe.The result of this study suggested that the presence of a link between Vc and the integrity of the vessels. Prolonged low intake of YC may be regarded as being one of the causal factors in the development of arteriosclerosis. The requirements of Vc for subjects with high cholesterol level may be more than those of normal subjects.

HYPOLIPIDEMIC AND LIPOTROPIC EFFECTS OF L-ASCORBATE 2-SULFATE / 营养学报

Tie effects of L-ascorbate 2-sulfate(AAS) on fatty liver and hyperli-pemia of rat and guinea pigs induced by various treatments were studied. The results showed that AAS lowered cholesterol and total lipid levels in the serum and liver of rats fed diets supplemented with lard and cholesterol, while ascorbic acid had no obvious effect. In guinea pigs, AAS not only lowered serum lipid values and liver cholesterol, triglyceride and total lipid levels of DDT treated animals, but also prevented from decline of body weights of these animals. It also had the same effects to lower the serum and liver lipid values of those animals fed pentabarbital or high lipid diet.Remarkable increases of the lipid peroxide value of animals given high doses of AsA were observed, but no such effect occurred in those fed AAS.