Taken together, the biochemical and behavioral findings of the present study suggest that KRGE produces anxiolytic effects via improvements in EW-induced mesoamygdaloid DA system dysfunction. DA receptors are members of the seven transmembrane domain G protein-coupled receptor family and are generally categorized into two different DA receptor subfamilies; the D1R (D1R and D5R) and D2R (D2R, D3R, and D4R) families [24]. DA afferents from the VTA innervate selleck kinase inhibitor the CeA and activate both D1R and D2R; however, autoradiographic and local infusion studies have shown that D1R and D2R have a differentiated distribution [25] and [26] and modulate anxiety differently. Behaviorally,
the activation of D1R in the CeA has anxiogenic consequences, KU-57788 mouse while the activation of D2R can produce either anxiogenic or anxiolytic effects depending on the nature of the stress experienced [27], [28] and [29]. In the present study, the anxiolytic effects of KRGE (60 mg/kg) on EW-induced anxiety-like behavior were blocked by the prior intra-CeA infusion of eticlopride (a selective D2R antagonist) but not SCH23390 (a
selective D1R antagonist), indicating that the anxiolytic effects of KRGE are mediated via D2R in the CeA. In summary, rats treated with KRGE (20 mg/kg/d or 60 mg/kg/d, three times) during EW exhibited an attenuation of EW-induced anxiety-like behavior, an inhibition of enhanced plasma CORT secretion, and a reversal of decreased levels of amygdaloid DA and DOPAC. In addition, KRGE (60 mg/kg/d, three times) restored the EW-induced decrease in TH protein levels in the CeA and TH mRNA levels in the VTA. Together, these findings suggest that KRGE exerts its anxiolytic
effects during EW via improvements in the mesoamygdaloid DA system. The authors declare no conflict of interest. This study was supported by the National Research Foundation of Korea (NRF) funded by Korea government (MSIP; No. 2011-0030124) and the Natural Science Foundation of Heilongjiang Province for Returned Scholars, China (LC201028). “
“Ginseng (the roots of Panax ginseng Meyer, Araliaceae) has been usually used as a traditional herbal pheromone medicine in Asian countries. The major components of ginseng are ginsenosides, which are glycosides with a dammarane skeleton aglycone [1] and [2]. These ginsenosides have been reported to show various biological activities including anti-inflammatory [3] and antitumor effects [4] and [5]. The pharmacological actions of these ginsenosides have been explained by the biotransformation of ginsenosides by human intestinal bacteria [6], [7] and [8]. Ginsenosides, glycosides with steroids or triterpenes as aglycones, are an important class of physiologically active compounds occurring in many herbs.