Ha Out Oil Selection And Mechanism Of Antidepressant Effective Parts

Depression is a common affective disorder, which is characterized by depressed mood and loss of interest or pleasure. There even exists suicidal thoughts and behaviors in patients with serious symptoms of depression. The latest survey showed that depression affected about10%of the world’s population, and16%people would be affected in some periods of their lives. In China, the incidence of depression is about3%-5%, and the suicide rate top the list of all mental disorders. Depression creates a significant threat to the lives and property of the people. With the development of economy and the acceleration of pace of life, the incidence of depression is increasing year by year. In addition, the pathogenesis of depression is complex, so the study of antidepressant treatments and their mechanism of action have become the research focus in today’s society.Traditional Chinese medicine (TCM) regards the depression as "Yu Zheng". In recent years, there is a growing concern about treating depression from kidney. Some scholars propose that deficiency of kidney energy is the essential reason of stagnation of liver-qi. They believe that the treatment of depression should be from kidney according to the theory of tonifying kidney, regulating qi flowing in the body and relieving uneasiness of mind.Ranae Oviductus (RO) is fallopian tubes of Rana temporaria chensinensis David, which has the effect of tonifying kidney, moistening lung and nourishment. RO is recorded in the2010edition of "Chinese Pharmacopoeia" and is usually used for treating weakness, fatigue, heart palpitations, insomnia, night sweats and cough, etc.. On the basis of the theory of TCM and the background of RO, antidepressant effective parts of RO was screened by modern medical research methods, and preliminary pharmacodynamics study and neural mechanisms were carried out. The aim of this study was to provide a theoretical basis for the development of new, effective and unique drugs for treating depression, and laid the foundation for the idea of "the treatment of depression from the kidney", extending the application of antidepressant Chinese medicines.The main contents and results are as follows:1Literature review1.1Research progress of depression in TCMAccording to the theory of TCM, the summary of this study included the history concept, etiology and pathogenesis, and syndrome differentiation of depression. Moreover, Chinese herbal compound and single herb for treating depression were also summarized.1.2Pathogenesis of depressionThis paper discussed the pathogenesis of depression from the neurotransmitter-receptor system, neuroendocrine system, immune system, the second messenger system and brain-derived neurotrophic factor etc. based on the related literature at home and abroad.1.3Animal models of depressionAccording to the reports of animal models about depression, the models were divided into six categories, including stress model, brain damage model, drugs-induced model, separation model, transgenic animals model and other models.1.4Research progress of ROReviewed the reports of chemical compositions and modern pharmacological studies of RO.2Experimental study2.1Screening of antidepressant effective parts and onset time of ROMale ICR mice were randomly divided into control and six treatment groups. The control group was given normal saline and treatment groups were received fluoxetine (20mg/kg/d), petroleum ether extracts (A,34.5mg/kg/d), ethyl acetate extracts (B,10.5mg/kg/d), n-butyl alcohol extracts (C,6mg/kg/d), and95%ethanol extracts (D,10.5mg/kg/d) from RO respectively. The doses were equivalent to the clinical doses. The forced swimming test (FST) and tail suspension test (TST) were conducted on the7th,8th,10th and14th day of administration. The results showed that A and D parts from RO could significantly shorten immobility time of mice in FST and TST on the8th day (P＜0.05), which verifying their antidepressant-like effects.2.2Antidepressant effects of petroleum ether extracts from RO2.2.1Optimal dose and mechanisms of antidepressant effects of petroleum ether extracts from ROMale ICR mice were randomly divided into control and six treatment groups. The control group was given normal saline and treatment groups were received ROS at doses of10,30,100,300,900mg/kg respectively for8days. One hour after the8th day administration, forced swimming test (FST) and tail suspension test (TST) were conducted for evaluation of behavior. And then the levels of serum corticosterone(CORT) in the mice were measured by radioimmunoassay method. The results showed that the group of100,300and900mg/kg ROS could significantly shorten immobility time of mice in FST and TST (P＜0.05), and decrease the CORT level in mice serum compared with control group (P＜0.05). The test indicated that petroleum ether extracts from Ranae Oviductus possessed antidepressant effects, and it might be related to HPA axis.2.2.2Effects of ROS on ethology and mechanisms of actions in rats exposed to chronic unpredictable mild stressThe chronic unpredictable mild stress lasted21days. Fluoxetine(10mg/kg/d) and ROS(30,100and300mg/kg/d) were administered after stress procedure every day, and the control and model groups were administered equivalent normal saline. Body weights were measured and depression-like behaviors were evaluated in the open-field test and sucrose preference test. Then the corticosterone levels in the rat plasma were detected by ELISA method and BDNF protein levels in the hippocampus were measured by western blotting analysis. The results showed that ROS100mg/kg significantly improved body weight, total distances and BDNF levels in rats and reduced the corticosterone level in the rat plasma, which suggested that the antidepressant-like effects of ROS was likely to be mediated by modulating the function of HPA axis and increasing the expression of BDNF in brain tissues.2.2.3Chemical composition analysis of ROSThe chemical compositions of ROS were detected by GC-MS method. The28identified constituents accounted for89.35%of total ion peak area. Among them,15kinds of fatty acid methyl esters were61.27%and palmitic acid was the highest in them; Two kinds of ketones accounted for16.29%of the peak area; Five sterols accounted for8.67%; Amide was2.75%; Alkanes had3types, which accounted for0.28%and2polyphenols were0.09%. Fatty acids, sterols, and amides substances were almost similar with what reported in the literature.Butylated hydroxytoluene, Phenol,3,5-bis(1,1-dimethylethyl)-,2(3H)-Furanone, dihydro-5-tetradecyl-2H-Pyran-2-one,tetrahydro-6-tridecyl-were first reported. According to literatures, it is presumed that the active ingredients of antidepressant effects in ROS may be fatty acids, amides and butylated hydroxytoluene, or new substances via their interaction. Whether Phenol,3,5-bis(1,1-dimethylethyl)-,2(3H)-Furanone, dihydro-5-tetradecyl-and2H-Pyran-2-one,tetrahydro-6-tridecyl-have antidepressant effects or not, it still needs further study.2.3Antidepressant effects of1-methylhydantoin2.3.1Qualitative analysis of1-methylhydantoin in D part from ROThe test solution and1-methylhydantoin standard solution were compared by HPLC. The results showed that D part from RO included1-methylhydantoin and the percentage of it is high.2.3.2Synthesis and purity test of1-methylhydantoinAccording to the reports,1-methylhydantoin was synthesized by chemical method and its purity was detected by HPLC. The results indicated that the purity1-methylhydantoin was more than98%.2.3.3Effects of1-methylhydantoin on ethology and mechanism of action in rats exposed to chronic forced swim stressThe rat model of depression was established by chronic forced swim stress. Fluoxetine(10mg/kg/d) and1-methylhydantoin(20,40and80mg/kg/d) were administered after stress procedure for14days. Body weights were measured and depression-like behaviors were evaluated in the open-field test and sucrose preference test. Then the corticosterone levels in the rat plasma were determined by ELISA method and BDNF protein levels in the hippocampus were measured by western blotting analysis. The results showed that compared with control group, chronic forced swim stress caused significant decreases of body weight, total distances and BDNF levels, and a significant increase of the corticosterone level in the rat plasma. Compared with the model group,1-methylhydantoin (40mg/kg) could significantly improve body weight, total distances and BDNF levels in rats and reduced the corticosterone level in the rat plasma. The results suggested that the antidepressant-like effects of1-methylhydantoin was likely to be mediated by modulating the function of HPA axis and increasing the expression of BDNF in brain tissues.