Effects of ginsenosides extracted from ginseng stem and leaves on glucocorticoid receptor in different viscera in heat-damaged rats

Abstract

To evaluate the effects of ginsenosides (GSS) extracted from ginseng stem and leaves on glucocorticoid receptor (GR) in different viscera in heat-damaged rats, and to find out its action mechanism. Thirty-two male SD rats were divided into control group and experimental group, and fed 2 mg/d GSS and equal-quantity of distilled water respectively for 7 days. Eight rats of each group were exposed to (42+/-1) degrees C for one hour. The binding activities of GR in brain, thymus, lung and liver cytosols in rats were detected by radioligand binding assay. The expression levels of GR mRNA in brain and liver cytosols were determined by reverse transcription-polymerase chain reaction (RT-PCR) assay. Plasma adrenocorticotropin (ACTH) and corticosterone (CS) concentrations were determined by radioimmunoassay. The binding activities of GR in brain, lung and liver cytosols, and the expression levels of GR mRNA in brain and liver cytosols were all higher in the GSS-treated and heat-damaged rats than those in the untreated heat-damaged rats (P<0.05 or P<0.01). There were no significant differences in plasma concentrations of ACTH and CS between the GSS-treated heat-damaged rats and the untreated heat-damaged rats. GSS can lessen the descending degree of the binding activity of GR in brain, thymus, lung and liver cytosols, and such efficacy of GSS may be related to improvement of the expression of GR mRNA.