Effects of ginsenosides on vascular reactivity in ovariectomized rats
Authors: Kim Sei , Lee Gyeong Hee , Yoo Hae Young 
Published: May 2023

Postmenopausal transition contributes to an increase in cardiovascular disease risk due to hormonal changes and changes in body fat distribution. Although it has been reported that ginsenosides from ginseng have various protective effects on endothelial cells or against hypertension damage, the effects of various ginsenosides remain controversial. Moreover, the effect of ginsenosides on the systemic vascular system in postmenopausal women is not well understood yet. In the present study, we investigated the effects of exposure to three different ginsenosides, Rg1, Rg3, and Rb1 on vascular reactivity from isolated mesenteric arteries of the postmenopausal rat model.7 week old female Sprague-Dawley rats (165 ~ 185 g) were purchased and acclimated for one week before being randomly divided into two groups. The control group (n=10) received a sham operation, while the experimental group (n=12) underwent bilateral ovariectomy (OVX) surgery for the postmenopausal rat modeling at 8 weeks of age. Body weight and non-invasive blood pressure was measured every 2 weeks. After 4 weeks, they were anesthetized and sacrificed. The isometric tension of the ring segments from the 2nd and 3rd branches of the mesenteric arteries was measured using a dual-wire myograph. The vascular reactivity with functional endothelium was tested by phenylephrine (PhE) 10 μM and acetylcholine 10 μM with and without incubation Rg1, Rg3, and Rb1 for 30 minutes in advance.The body weight of the OVX group increased significantly compared to that of the control group after 2 weeks and 4 weeks of surgery ( p<.001). Compared to the control group, the OVX group showed significantly increased mean arterial pressure only after 2 weeks of surgery, not after 4 weeks ( p=.005). In the OVX group, the maximal constriction (Emax) in response to both high-K and PhE-induced vasoconstriction significantly increased compared to the control group ( p<.05; p<.05). PhE-induced vasoconstriction was significantly reduced in the OVX group but not in the control group in the presence of Rg1 ( p<.001). Rg3 incubation significantly reduced PhE-induced vasoconstriction in both groups ( p<.001; p<.001). Interestingly, the OVX group showed a relatively greater contractile response than the control group in the presence of Rg3 ( p<.005), whereas there was no change in PhE-induced constriction in both groups in the presence of Rb1. There was partially impaired vasorelaxation by acetylcholine after Rb1, Rg1, and Rg3 incubation in both groups.In conclusion, it is suggested that vascular reactivity was enhanced in OVX rat models compared to that of control. In addition, Rg1 and Rg3 had differential effects on the vascular contractility of the OVX and control groups. Ach-induced vasorelaxation was also affected by Rb1, Rg1, and Rg3 in both groups. Further investigation is required to elucidate the underlying mechanisms of these effects. This study was supported by National Research Foundation of Korea grant funded by Ministry of Science, ICT, & Future Planning (NRF-2022R1F1A1068307). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.