Objective: To evaluate the effect of ginsenoside pre-treatment on serotonin (5-hydroxytryptamine, 5-HT), 5-HT2A receptor (5-HT2AR), and 5-HT transporter (serotonin transporter, SERT) in serum, platelet lysate and brain tissue homogenates in SD rats with myocardial infarction (MI) or depression.
Methods: Eighty SD rats were randomized treated with ginsenoside or normal saline(NS). After 4 weeks, the rats were, then, randomized to four subgroups: the MI, the depression, the MI in combination with depression and sham subgroups.5-HT, 5-HT2AR and SERT levels were detected in serum, platelet or brain.
Results: In the NS pre-treatment groups, serum 5-HT levels in sham rats (237.1±32.0) pg/ml were higher than in MI (58.0±11.6) pg/ml, depression (72.8±2.3) pg/ml, and MI with depression rats (62.5±10.2) pg/ml (all P=0.000). Pre-treatment of ginsenoside increased serum and platelet 5-HT in MI, depression and MI with depression rats compared with each corresponding NS treated subgroups (all P<0.005). However, treatment of ginsenoside lowered the 5-HT2AR expression in MI, depression, and MI with depression subgroups both in platelet and brain tissue homogenates compared with each corresponding NS treated subgroups (all P<0.05). As to SERT in platelet, treatment of ginsenoside increased its levels in depression rats (P=0.019), but lowered the levels in MI rats (P=0.001) compared with NS treated rats.There were no differences in brain 5-HT and SERT between ginsenoside and NS treated groups.
Conclusions: The 5-HT system responses differently to ginsenoside treatment under different cardiac and mental stress conditions.Ginsenoside plays an important role in regulation of 5-HT system.