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Protection of vascular endothelial cells from hydrogen peroxide‐induced oxidant injury by gypenosides, saponins of Gynostemma pentaphyllum
Author(s) -
Li Lin,
Lau Benjamin H. S.
Publication year - 1993
Publication title -
phytotherapy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 129
eISSN - 1099-1573
pISSN - 0951-418X
DOI - 10.1002/ptr.2650070408
Subject(s) - tbars , gynostemma pentaphyllum , viability assay , lipid peroxidation , lactate dehydrogenase , chemistry , pharmacology , hydrogen peroxide , thiobarbituric acid , biochemistry , endothelial stem cell , reactive oxygen species , antioxidant , apoptosis , medicine , in vitro , enzyme , chromatography , extraction (chemistry)
Lipid peroxidation and toxicity associated with oxygen radicals have been suggested as major causes of cancer, atherosclerosis and the aging process. Damage of endothelial cells may lead to cardiovascular and cerebrovascular diseases. Endothelial cells are susceptible to oxidant insult. In the present study, the antioxidant effect of a Chinese medicinal herb, Gynostemma pentaphyllum Makino (Chinese name, Jiaogulan), was investigated in vitro using vascular endothelial cells. Confluent monolayers of bovine pulmonary artery endothelial cells (PAEC) were preincubated with different concentrations of gypenosides (GP, total saponins of Gynostemma pentaphyllum ) for 16 h, then washed and incubated with hydrogen peroxide (H 2 O 2 ) for 4 h. Cell injury was assessed by measuring the release of intracellular lactate dehydrogenase (LDH), and cell viability with tetrazolium (MTT) assay. Lipid peroxidation products of PAEC were monitored as thiobarbituric acid‐reactive substances (TBARS) with a fluorometric assay. The results showed that 62.5 μM H 2 O 2 incubated with PAEC for 4 h increased the percentage of LDH release, decreased cell viability manifested by MTT absorbance at 620 nm, and elevated TBARS. Preincubation of GP (25–150 μg/mL) with PAEC for 16 h before H 2 O 2 exposure significantly declined LDH release, increased cell viability, and reduced TBARS. These results demonstrate that gypenosides can protect vascular endothelial cells from oxidant injury. The data thus suggest that gypenosides may be beneficial for the prevention and treatment of atherosclerosis and for retardation of the aging process.