Study on the sedative and hypnotic active ingredients of walnut distraction wood
Diaphragma Juglandis Fructus (DJF), also known as walnut diaphragm or walnut valve. The traditional medicinal uses of Walnut distraction wood include the treatment and prevention of diabetes, kidney deficiency, diarrhea and diseases of the urinary and reproductive system. In vitro and in vivo studies have found that in addition to its traditional kidney tonifying effects, distracted wood also has sedative hypnotic, antioxidant, anti-inflammatory, anti-tumor and other effects, which can be applied in the development of products in related fields such as health food and medicine.

Approximately 10% to 15% of adults worldwide suffer from chronic insomnia, while another 25% to 35% suffer from transient or occasional sleep disorders. In addition to affecting the quality of daily life and work efficiency, these obstacles can also lead to various health and socio-economic problems. In the traditional treatment of insomnia, medication is the most commonly used, such as benzodiazepines and non benzodiazepines, which can exert sedative and hypnotic effects to improve the patient’s condition; However, long-term use may lead to habituation and withdrawal symptoms. Faced with these limitations, people tend to seek natural medicines that are effective, safe, and have fewer side effects to treat or alleviate insomnia symptoms.

At present, research on the sedative and hypnotic activity of distracted wood mainly focuses on crude extracts, and specific functional components have not been identified. Zhao found that the water extract of distracted wood can shorten the sleep latency induced by pentobarbital sodium in mice, prolong sleep duration, and tend to reduce spontaneous activity. This article uses mouse open field experiments and pentobarbital sodium induced sleep experiments to guide the separation direction. Monomeric compounds with sedative and hypnotic activity are gradually separated through column chromatography and thin layer chromatography, and their structures are identified by nuclear magnetic resonance technology. The research results can provide theoretical basis for the development and utilization of walnut distraction wood resources, and increase the added value of walnut resources.

At present, the natural sedative and hypnotic ingredients that have been clearly studied include sugars, flavonoids, lignans, coumarins, and saponins. The distracted wood containing sugars, flavonoids, lignans, phenols, and saponins may have good therapeutic effects in sedative and hypnotic aspects. This study investigated the sedative and hypnotic effects of walnut distraction wood and its active ingredients. The open field experiment and pentobarbital induced sleep experiment are two classic behavioral methods for evaluating sedative and hypnotic activity in pharmacology. The average movement speed and time of mice measured in open field experiments are generally considered important indicators for controlling sleep activity. This study indicates that compound 2 can reduce the average movement speed and time of normal mice, and increase the time spent in the central region. In addition, the latency and sleep duration obtained from sleep tests induced by pentobarbital sodium (short-term sedative and hypnotic drugs) are often used as indicators to evaluate the sedative and hypnotic effects of the substance. Compound 1 did not shorten the latency period, but it can prolong the duration of sleep; Compound 2 can shorten sleep latency and prolong sleep duration. And both can increase the sleep duration of mice within 12 hours under natural conditions. Compound 2 (3-hydroxy-4-aminobutyric acid) exhibits significant sedative and hypnotic activity, possibly due to its structural similarity to gamma aminobutyric acid, thus possessing similar activity.

According to reports, the mechanism by which the active ingredients of traditional Chinese medicine with sedative and hypnotic functions exert their effects includes: (1) regulating central neurotransmitters. Neurotransmitters not only play an important role in regulating normal sleep wake rhythms, but also in the process of disturbances. Schisandrin B exerts a hypnotic effect in a rat model of insomnia induced by phenylalanine by increasing the levels of 5-HT and gamma aminobutyric acid in the hypothalamus. (2) Affects sleep related cytokines such as cholecystokinin, orexin, and other endogenous substances. Zeng Xueai and others found that the sedative and hypnotic mechanism of the Songyu Anshen Formula may be related to regulating the content of endogenous sleep promoting substance PGD2 in the hypothalamus. Therefore, compounds 1 and 2 may exert sedative and hypnotic effects through the above two pathways, and the specific mechanism of action remains to be further studied.

The macroporous resin water washed extract of walnut distraction wood has sedative and hypnotic activity. After separation by MCI, the effective components are concentrated in the MCI water washed extract. Four monomer compounds were further isolated, namely 2-hydroxymethyl-tetrahydropyran-3,4,5-triol (1), 3-hydroxy-4-aminobutyric acid (2), (1 ‘- methyl-2’ – hydroxy) propane-O – α – D-glucopyranose (3), and 6-hydroxynaphthyl-1,2- (2-O – β – D-glucopyranose) (4). This article preliminarily determines through animal experiments that 2-hydroxymethyl-tetrahydropyran-3,4,5-triol only has the effect of prolonging sleep time in mice, while 3-hydroxy-4-aminobutyric acid has sedative and hypnotic functional activity. The above research provides theoretical support for the application of distraction wood in the treatment of insomnia, laying the foundation for the development of subsequent health food drugs and the clinical application of sedative and hypnotic effects.