title: Rhizoma Pinelliae trypsin inhibitor separation, purification and inhibitory activity on the proliferation of BGC-823 gastric adenocarcinoma cells.
abstract: The aim of this study was to isolate and purify Rhizoma Pinelliae trypsin inhibitor (RPTI), determine its N-terminal amino acid sequence and evaluate its inhibitory effect on the proliferation of poorly differentiated BGC-823 human gastric adenocarcinoma cells. RPTI was separated and purified from a 40% (NH4)2SO4precipitate of crude protein extract ofPinellia ternatatuber using affinity chromatography with trypsin as the ligand. The N-terminal amino acid sequence of RPTI was determined using the Edman degradation method. The inhibitory effect of RPTI on BGC-823 cell proliferation was detectedin vitrousing the MTT method andin vivoin tumour-bearing mice. The purified RPTI showed a single band under SDS-PAGE, its molecular weight was 14 kDa and its N-terminal amino acid sequence was DPVVDG. RPTI inhibited trypsin activity, with an inhibition ratio of 1:6.78 (mass). RPTI significantly inhibited the proliferation of BGC-823 cellsin vitro. The IC50of RPTI was 16.96 μg/ml within 48 h after treatment and 9.61 μg/ml within 72 h after treatment. Subcutaneous injection of RPTI around the tumour significantly inhibited BGC-823 tumour growth in mice. The tumour inhibitory effect was concentration- and dose-dependent. RPTI did not significantly influence the spleen coefficient of the mice. In conclusion, RPTI is a serine proteinase inhibitor with antitumour activity.
authors.affiliation: Department of Radiation Oncology, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China.
authors.forename: Guohong
authors.initials: G
authors.lastname: Zu
authors.affiliation: Department of Chinese Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250013, P.R. China.
authors.forename: Houwei
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Surgery, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Dou
authors.affiliation: Department of Radiation Oncology, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China.
authors.forename: Weichong
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Department of Radiation Oncology, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Sun
keywords: Pinellia; human poorly differentiated gastric adenocarcinoma; trypsin inhibitor