Directional screening and identification of potential cytotoxic components from Achnatherum inebrians by a combination of surface palsmon resonance and chromatography / 中草药·英文版

OBJECTIVE@#To establish a method for directional screening of the cytotoxic components from the medicinal herb of Achnatherum inebrians by a combination of surface plasmon resonance (SPR) biosensor and chromatographic isolation technology.@*METHODS@#Under the guidance of bioactive assessment based on binding abilities between objects and the α-Mannosidase (α-Man) target, the active components from different solvents extracts, different polar extraction parts and fractions were screened orderly and directionally using SPR. Components with a high binding ability to α-Man can be precisely oriented in a narrower fractions range and are easy to isolate. Three human cancer cells were used to evaluate the cytotoxic activity of component with the highest affinity to α-Man.@*RESULTS@#Eight compounds were isolated and identificated from A. inebrians for the first time. Deoxyvasicinone possessed the highest affinity to α-Man among them. Moreover, deoxyvasicinone showed good effects on inhibited proliferation of human hepatoma cells HepG2 (IC50 = 5.7 μmol/L), human breast cancer cells MCF7 (IC50 = 7.21 μmol/L) and human lung cancer cells HCC827 (IC50 = 0.75 μmol/L), respectively. In particular, its inhibitory effect on HCC827 was stronger than the positive drug gefitinib (IC50 = 1.65 μmol/L).@*CONCLUSION@#A comprehensive strategy of directional screening potential cytotoxic components from herb based on biomolecular interaction and chromatography was established. Deoxyvasicinone as an effective anti-cancer component was initially isolated from A. inebrians. It is expected that this screening strategy could provide new perspectives for rapid screening and identification of active components from natural plants with the complex matrix.

The expressions of GM II, E-cadherin and α-catenin in ovarian epithelial tumor tissues and ovarian cancer cells with different abilities of metastasis / 肿瘤

Objective: To detect the expressions of GM II (Golgi α-mannosidase II), E-cadherin and α-catenin in ovarian epithelial tumor tissues and ovarian cancer cells with different abilities of metastasis. Methods: The expressions of GM II, E-cadherin and α-catenin proteins in ovarian epithelial malignant tumor tissues from 46 cases (including 27 cases of omentum metastasis or lymph node metastasis), ovarian epithelial borderline tumor tissues from 15 cases, and ovarian epithelial benign tumor tissues from 12 cases were detected by immunohistochemistry. The expression levels of GM II, E-cadherin and α-catenin mRNAs and proteins in A2780, SKOV-3 and HO-8910 cells with different abilities of metastasis were detected by RT-PCR, immunofluorescence and Western blotting, respectively. Results: The positive rate of GM II (87%) and the abnormal expression rates of E-cadherin (80%) and α-catenin (72%) in ovarian epithelial malignant tumor tissues were significantly higher than those in ovarian epithelial borderline tumor tissues (60%, 20% and 40%) and epithelial benign tumor tissues (42%, 0% and 17%), which were also higher in tumor tissues with omentum metastasis or lymph node metastasis than those without omentum metastasis or lymph node metastasis (P < 0.05). The fluorescence density of GM II was gradually increased in A2780, SKOV-3 and HO-8910 cells, whereas the fluorescence density of E-cadherin and α-catenin was gradually decreased. The expression levels of GM II mRNAs and proteins was gradually increased in A2780, SKOV-3 and HO-8910 cells, whereas the expression levels of E-cadherin and α-catenin mRNAs and proteins were gradually decreased, and the difference were statistically significant among the three cell lines (P < 0.05). Conclusion: GM II, E-cadherin, and α-catenin may play an important role in malignant progression of ovarian tumors, and GM II may become a predictor of prognosis and a therapeutic target for ovarian tumors. Copyright © 2012 by TUMOR.

Isolation and characterization of lysosomal alpha-mannosidase of placental tissue.

The acidic α-mannosidase was purified 4400-fold by affinity chromatography on Concavalin A-Sepharose and heat treatment at 65°C in the presence of 1 mM zinc ion. The enzyme did not resolve into multiple forms as in the case of enzymes from human liver and human kidney. The pH optimum of the enzyme was 4.2 in citrate-phosphate buffer. The Km value for p-nitrophenyl-α-D-mannose was 1.9 mM. The molecular weight of the enzyme determined by gel filtration was 300,000. The enzyme contained 10.6% neutral sugars.