Study On Hypnotic Effect And Mechanism Of Rare Ginsenosides

Ginsenoside is the main active ingredient of ginseng plants(ginseng,notoginseng,American ginseng,etc.),which has anti-fatigue,anti-aging,immune-enhancing,anti-tumor effects.However,few people are concerned about their hypnotic effects.Sleep problems,especially insomnia,are more and more frequent in current society,which seriously affects human health.Most hypnotic drugs have side effects such as dependence and drowsiness,so developing a hypnotic nutrition which is safe and has no side effects is efficient.Thus health products have become the focus of research.Ginsenoside has attracted strong attention and in-depth research by researchers because of its remarkable pharmacological activity.In this study,the hypnotic effect of rare Protopanaxadiol-type(PD),Protopanaxatriol-type(PT)ginsenosides and rare ginsenoside monomer Rk3 extracted from major saponins and their involved mechanisms were investigated.1.Animals were induced to sleep by a hypnotic dose of pentobarbital sodium in animal experiments.The sleep latency and sleep duration of each group of mice were observed and recorded to determine the effective hypnotic dose of rare ginsenosides PD,PT and Rk3.The experimental results show that ginsenosides PD and PT have hypnotic effect and their effective dose is 64-96 mgkg.In addition,the hypnotic effect of PD was increased with the increase of concentration.Whereas the effect of PT has no significant change with the change of effective concentration.The effective dose of ginsenoside Rk3 ranges from 50-70 mg/kg,in which the hypnotic effect was improved with the increase of concentration.2.Insomnia model was established by using caffeine and p-chlorophenylalanine(PCPA)in mice,respectively,and then they were administrated by intragastric administration.We combine ginsenoside PD and PT with 5-hydroxytryptophan (5-HTP)and fumazenil(FLU),the sleep latency and sleep of each group of mice was observed and recorded.The results showed that rare ginsenosides PD and PT can effectively inhibit insomnia caused by caffeine and PCPA,and they are synergistic with 5-HTP in improving sleep.In addition,the hypnotic effect of rare ginsenosides PD and PT was inhibited by FLU.These data indicated that the mechanism involves serotoninergic system and GABA receptor.3.To investigate whether Rk3 improves sleep by participate in the serotoninergic system,rare ginsenoside Rk3 with PCPA and 5-HTP was combined,respectively,and Elisa kit was used to measure 5-HT levels in the cortex,hypothalamus and blood of mice after administration.The results showed that ginsenoside Rk3 can significantly inhibit PCPA-induced insomnia,and have a synergistic effect with 5-HTP to improve sleep.In the Elisa kit test results,the 5-HT level in serum of mice did not change,of which both in the cortex layers and hypothalamus were increased and in a dose-dependent manner.It suggests that rare ginsenoside Rk3 plays a have a hypnotic effect and involve the serotoninergic system.Therefore,rare ginsenosides PD,PT and Rk3 are expected to become a sort of safe and non-toxic nutritious food,who have an efficient effect in sedative and hypnotic.