Pretreatment with Ginseng Fruit Saponins Affects Serotonin Expression in an Experimental Comorbidity Model of Myocardial Infarction and Depression

We previously demonstrated that serotonin (5-HT) and 5-HT(2A) receptor (5-HT(2A)R) levels in platelets were up- or down-regulated after myocardial infarction (MI) associated with depression. In this study, we further evaluated the effects of pretreatment with ginseng fruit saponins (GFS) on the expression of 5-HT and 5-HT(2A)R in MI with or without depression. Eighty Sprague-Dawley (SD) rats were treated with saline and GFS (n=40 per group). The animals were then randomly divided into four subgroups: sham, MI, depression, and MI + depression (n=10 per subgroup). Protein levels of 5-HT and 5-HT(2A)R in the serum, platelets and brain tissues were determined with ELISA. The results demonstrated that serum 5-HT levels was significantly increased by GFS pretreatment in all subgroups (except the sham subgroup) when compared with saline-treated counterparts (p<0.01). In platelets, GFS pretreatment significantly increased 5-HT levels in all subgroups when compared with their respective saline-treated counterparts (p<0.01). Brain 5-HT levels also declined with GFS pretreatment in the MI-only and depression-only subgroups (p<0.05 vs. saline pretreatment). With respect to 5-HT(2A)R levels, platelet 5-HT(2A)R was decreased in GFS pretreated MI, depression and MI + depression subgroups (p<0.01 vs. saline pretreatment). Similarly, brain 5-HT(2A)R levels decreased in all four subgroups pretreated with GFS (p<0.01 vs. saline pretreatment). We conclude that GFS plays a clear role in modulating 5-HT and 5-HT(2A)R expressions after MI and depression. Although the effects of GFS on brain 5-HT remain to be elucidated, its therapeutic potential for comorbidities of acute cardiovascular events and depression appears to hold much promise.