Shu‑Yu capsule, a Traditional Chinese Medicine formulation, attenuates premenstrual syndrome depression induced by chronic stress constraint

ShuYu capsule alleviates emotional and physical symptoms of premenstrual dysphoric disorder: Impact on ALLO decline and GABAA receptor δ subunit in the PAG area

Premenstrual dysphoric disorder (PMDD) is a severe subtype of premenstrual syndrome in women of reproductive age, with its pathogenesis linked to the heightened sensitivity of type A γ -aminobutyric acid receptors (GABAAR) to neuroactive steroid hormone changes, particularly allopregnanolone (ALLO). While a low dose of fluoxetine, a classic selective serotonin reuptake inhibitor, is commonly used as a first-line drug to alleviate emotional disorders in PMDD in clinical settings, its mechanism of action is related to ALLO-GABAA receptor function. However, treating PMDD requires attention to both emotional and physical symptoms, such as pain sensitivity. This study aims to investigate the efficacy of ShuYu capsules, a traditional Chinese medicine, in simultaneously treating emotional and physical symptoms in a rat model of PMDD. Specifically, our focus centres on the midbrain periaqueductal grey (PAG), a region associated with emotion regulation and susceptibility to hyperalgesia. Considering the underlying mechanisms of ALLO-GABAA receptor function in the PAG region, we conducted a series of experiments to evaluate and define the effects of ShuYu capsules and uncover the relationship between the drug's efficacy and ALLO concentration fluctuations on GABAA receptor function in the PAG region. Our findings demonstrate that ShuYu capsules significantly improved oestrous cycle-dependant depression-like behaviour and reduced stress-induced hyperalgesia in rats with PMDD. Similar to the low dose of fluoxetine, ShuYu capsules targeted and mitigated the sharp decline in ALLO, rescued the upregulation of GABAAR subunit function, and activated PAG neurons in PMDD rats. The observed effects of ShuYu capsules suggest a central mechanism underlying PMDD symptoms, involving ALLO_GABAA receptor function in the PAG region. This study highlights the potential of traditional Chinese medicine in addressing both emotional and physical symptoms associated with PMDD, shedding light on novel therapeutic approaches for this condition.

The potential role of the orexin system in premenstrual syndrome

Premenstrual syndrome (PMS) occurs recurrently during the luteal phase of a woman's menstrual cycle and disappears after menstruation ends. It is characterized by abnormal changes in both the body and mood, and in certain cases, severe disruptions in daily life and even suicidal tendencies. Current drugs for treating PMS, such as selective serotonin reuptake inhibitors, do not yield satisfactory results. Orexin, a neuropeptide produced in the lateral hypothalamus, is garnering attention in the treatment of neurological disorders and is believed to modulate the symptoms of PMS. This paper reviews the advancements in research on sleep disturbances, mood changes, and cognitive impairment caused by PMS, and suggests potential pathways for orexin to address these symptoms. Furthermore, it delves into the role of orexin in the molecular mechanisms underlying PMS. Orexin regulates steroid hormones, and the cyclic fluctuations of estrogen and progesterone play a crucial role in the pathogenesis of PMS. Additionally, orexin also modulates the gamma-aminobutyric acid (GABA) system and the inflammatory response involved in coordinating the mechanism of PMS. Unraveling the role of orexin in the pathogenesis of PMS will not only aid in understanding the etiology of PMS but also hold implications for orexin as a novel target for treating PMS.

Shuyu capsule alleviates premenstrual depression via allopregnanolone metabolic pathway targeting GABA (A) receptors δ subunit in the hippocampus

To reveal the exact changes of allopregnanolone-mediated γ-aminobutyric acid A receptor pathways and its specific therapeutic targets by Shuyu Capsule treating premenstrual depression, female Wistar rat models of premenstrual depression was established by Forced swimming test (FST). Behavioral tests, enzyme-linked immunosorbent assay (ELISA), interference knockdown adenovirus, and overexpressed vector adenovirus of GABAARδ, RT-qPCR, Western-Blot, and immunohistochemical detecting expressions were applied to identify the therapeutic targets. FST-based rat model indicated that Shuyu capsules alleviated typical premenstrual depression and may regulate alternations of 5α-reductase and 3α-steroid dehydrogenase, enhancing the metabolic pathway of progesterone to allopregnanolone, as well as targeting the GABAARδ subunit, thereby alleviating premenstrual depression of PMDD rat models.

Profiling GABA(A) Receptor Subunit Expression in the Hippocampus of PMDD Rat Models Based on TCM Theories

γ-Aminobutyric acid type A receptors (GABAARs) play an important role in cognitive and emotional regulation and are related to the hippocampus. However, little is known regarding patterns of hippocampal GABAAR subunit expression in rat models of premenstrual dysphoric disorder (PMDD). This study investigated the above changes by establishing two PMDD rat models based on Traditional Chinese Medicine (TCM) theories, namely, PMDD liver-qi invasion syndrome (PMDD-LIS) and PMDD liver-qi depression syndrome (PMDD-LDS). Behavioral tests were used to detect depression and irritability emotion. Western blot analysis was used to investigate protein levels of GABAAR α1, α2, α4, α5, β2, β3, and δ subunits, whereas ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis was performed to determine gamma-aminobutyric acid (GABA) and glutamate (Glu) levels in the hippocampus across each group. Concurrently, behavioral data indicated that the PMDD-LDS and PMDD-LIS rat models had been successfully established. GABAAR α2, α5, β2, and δ subunit was significantly upregulated, whereas α4 was significantly downregulated (P < 0.05) in PMDD-LDS rat models relative to controls. On the other hand, GABAAR α1, α2, and β3 were significantly downregulated while α4 and β2 were significantly upregulated in PMDD-LIS rat models relative to the control group (P < 0.05). Moreover, GABA levels significantly decreased, while Glu and the ratio of glutamate to GABA increased in PMDD-LIS rat models (P < 0.05). Conversely, GABA and Glu levels significantly decreased, whereas the ratio of glutamate to GABA increased in PMDD-LIS rat models (P < 0.05). Conclusively, our results revealed differential expression of GABAAR α1, α2, α4, α5, β2, β3, and δ subunits between PMDD-LIS and PMDD-LDS rat models, suggesting that they may be biomarkers in the pathogenesis of PMDD.

Baixiangdan capsule and Shuyu capsule regulate anger-out and anger-in, respectively: GB1–mediated GABA can regulate 5-HT levels in multiple brain regions

The identity of the mechanism by which the Baixiangdan capsule (BXD) and the Shuyu capsule (SY) control anger-out (AO) and anger-in (AI) in rodents is unclear. The current study clarified the intervention role of BXD and SY on AO and AI male rats. We further explored the differences between BXD and SY in the treatment of AO and AI rats. Social isolation combined with the resident-intruder paradigm was used to establish the anger-out and AI rats models. On this basis, GABA content in the dorsal raphe nucleus (DRN) and serotonin (5-HT) contents in these brain regions were detected using ELISA after various time courses (0, 1, 3, 5, and 7 days) treated with BXD and SY. Co-expression of 5-HT and GB1 in the DRN was detected. GB1-specific agonist baclofen and GB1-specific inhibitor CGP35348 were injected into the DRN. Changes in 5-HT levels in these brain regions were then detected. After treatment, rats in the BXD group exhibited lower aggressive behavior scores, longer latencies of aggression, lower total distances in the open field test, and a higher sucrose preference coefficient. Meanwhile, rats in the SY group exhibited higher aggressive behavior scores, shorter latencies of aggression, higher total distances in the open field test, and higher sucrose preference coefficients. With increasing medication duration, 5-HT levels in these brain regions were increased gradually, whereas GABA levels in the DRN were decreased gradually, and all recovered to normal levels by the 7th day. A large number of 5-HT-positive cells could be found in the immunofluorescence section in the DRN containing GABABR1 (GB1)-positive cells, indicating that 5-HT neurons in the DRN co-expressed with GB1. Furthermore, after the drug intervention, the 5-HT level in the DRN was elevated to a normal level, and the GB1 level in the DRN was decreased to a normal level. After the microinjection of baclofen into the DRN, the 5-HT contents in these brain regions were decreased. By contrast, the 5-HT contents were increased after injection with CGP35348. BXD and SY could effectively improve the abnormal behavior changes of AO and AI rats, and the optimal duration of action was 7 days. The improvement way is as follows: Decreased abnormal increase of GABA and GB1 in the DRN further mediated synaptic inhibition and increased 5-HT level in the DRN, leading to increased 5-HT levels in the PFC, hypothalamus, and hippocampus. Therefore, GB1-mediated GABA in the DRN could regulate 5-HT levels in these brain regions, which may be one of the ways by which BXD and SY treat AO and AI, respectively.

The role of the excitation:inhibition functional balance in the mPFC in the onset of antidepressants

Currently available antidepressants, such as selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs), generally require weeks to months to produce a therapeutic response, but the mechanism of action underlying the delayed onset of antidepressant-like action remains to be elucidated. The balance between excitatory glutamatergic pyramidal neurons and inhibitory γ-aminobutyric acid (GABA) interneurons, i.e., the excitation:inhibition functional (E:I) balance, in the medial prefrontal cortex (mPFC) is critical in regulating several behaviors and might play an important mediating role in the mechanism of rapid antidepressant-like action reported by several studies. In the present study, the multichannel electrophysiological technique was used to record the firing activities of pyramidal neurons and interneurons and investigate the effects of a single dose of fluoxetine and ketamine (both 10 mg/kg, i.p.) on the E:I functional balance in the rat mPFC after 90 min or 24 h, and the forced swimming test (FST) was used to evaluate the antidepressant-like effects of fluoxetine and ketamine. The present study also explored the effects of chronic treatment with fluoxetine (10 mg/kg, i.g.) for 7 d or 21 d on the E:I functional balance in the mPFC. The present results suggested that a single dose of ketamine could both significantly increase the firing activities of pyramidal neurons and significantly decrease the firing activities of interneurons in the mPFC and exerted significant antidepressant-like action on the FST after 90 min and 24 h, but fluoxetine had no such effects under the same conditions. However, chronic treatment with fluoxetine for 21 d (but not 7 d) could significantly affect the firing activities of pyramidal neurons and interneurons in the mPFC. Taken together, the present results indicated that rapid regulation of the E:I functional balance in the mPFC might be an important common mechanism of rapid-acting antidepressants and the delayed onset of SSRIs might be partly attributed to their inability to rapidly regulate the E:I functional balance in the mPFC. The present study provided a new entry point to the development of rapid-acting antidepressants.

Effect of the warming and tonifying kidney- yang recipe on monoamine neurotransmitters and pathological morphology of hippocampus tissue in depression model rats

OBJECTIVE:

To study the molecular mechanism of warming and tonifying kidney-yang recipe (WTKYR) in the treatment of depression.

METHODS:

SD rats were divided into a control group, model group, WTKYR group, and fluoxetine group. Each group consisted of 21 rats. The chronic unpredictable mild stress model was used. Body weighing and SPT were performed regularly. After treatment, histopathology of the brain tissue was performed, and concentrations of 5-HT (5-hydroxytryptamine), NE (norepinephrine), and DA (dopamine) in the hippocampus were determined.

RESULTS:

The WTKYR group showed higher body weight and sucrose consumption than the control groups. Moreover, the concentrations of 5-HT, NE, and DA in the hippocampus were significantly different in the WTKYR group in comparison to those in the other groups. The hippocampus histomorphology of the WTKYR group exhibited less dematous pyramidal cells and mild inflammatory cell infiltration.

CONCLUSION:

The treatment effect of WTKYR in depression may be based on improvement in the content of 5-HT, NE, and DA in the hippocampus, extenuating edema of the cortical surface and pyramidal cells and decreasing the infiltration of inflammatory cells into hippocampus tissue.

The Chinese Herbal Formula PAPZ Ameliorates Behavioral Abnormalities in Depressive Mice

Major depressive disorder (MDD) is a chronic mental disorder characterized by mixed symptoms and complex pathogenesis. With long history of practical application, traditional Chinese medicine (TCM) offers many herbs for the treatment and rehabilitation of chronic disease. In this study, we developed a modified Chinese herbal formula using Panax ginseng, Angelica Sinensis, Polygala tenuifolia Willd, and Ziziphi spinosae Semen (PAPZ), based on an ancient TCM prescription. The antidepressant effects of PAPZ were investigated with a corticosterone (CORT) model of depression in mice. Our results showed that administration of PAPZ ameliorated depression-like phenotypes in the CORT model. An anatomic study showed that chronic PAPZ administration upregulated the protein expression of brain-derived neurotrophic factor (BDNF) in hippocampal tissue. The enzyme activity of superoxide dismutase was enhanced in hippocampal tissue, in line with a decreased malondialdehyde level. Taken together, these findings suggested that PAPZ has therapeutic effects in a mice depression model through increasing protein expression of BDNF and improving the anti-oxidation ability of the brain.

An East Meets West Approach to the Understanding of Emotion Dysregulation in Depression: From Perspective to Scientific Evidence

Depression, an emotion regulation disorder, is a prevalent mental illness in the world. Meanwhile, traditional Chinese medicine (TCM) has been increasingly regarded as a promising and effective alternative therapy approach for patients with depression. Despite many years of research on depression, the current understanding of the pathological mechanism of depression based on TCM theories is still in its infancy. Due to the lack of scientific evidence in the past, TCM is not fully recognized by researchers around the world. This review firstly summarizes the pathogenesis and etiology of depression in terms of both Eastern and Western medical systems. Secondly, it adopts an integrated Eastern and Western approach to propose some plausible neurophysiological pathways linking the liver, spleen, and heart functions explicated in TCM theory. The aim of this theoretical review is to bridge the knowledge gap between Eastern and Western medicine, which may better explain the pathology of depression.

Activation of the hippocampal AC-cAMP-PKA-CREB-BDNF signaling pathway using WTKYR in depression model rats

Depression, also called "depression disorder," is characterized by a significant and persistent low mood. It has become a major refractory disease in the 21st century. In recent years, Chinese medicine has shown some important clinical value in the treatment of depression. Among them, the Warming and "Tonifying" Kidney-Yang Recipe (WTKYR) has been demonstrated to have obvious effects in the clinical treatments of depression; however, the mechanism remains unclear. This study is based on the adenylyl cyclase (AC)-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA)-cAMP response element-binding protein (CREB)-brain derived neurotrophic factor (BDNF) signaling pathway, aiming to investigate the mechanism of WTKYR. The results showed that WTKYR can upregulate AC-cAMP-PKA-CREB-BDNF in the hippocampus of depression model rats and alleviate its depressive symptoms, which may be the mechanism of WTKYR.

Altered Brain Regional Homogeneity Following Electro-Acupuncture Stimulation at Sanyinjiao (SP6) in Women With Premenstrual Syndrome

Background: Premenstrual syndrome (PMS) is a menstrual cycle-related disorder which causes physical and mood changes prior to menstruation and is associated with the functional dysregulation of the brain. Acupuncture is an effective alternative therapy for treating PMS, and sanyinjiao (SP6) is one of the most common acupoints used for improving the symptoms of PMS. However, the mechanism behind acupuncture's efficacy for relieving PMS symptoms remains unclear. The aim of this study was to identify the brain response patterns induced by acupuncture at acupoint SP6 in patients with PMS. Materials and Methods: Twenty-three females with PMS were enrolled in this study. All patients underwent resting-state fMRI data collection before and after 6 min of electroacupuncture stimulation (EAS) at SP6. A regional homogeneity (ReHo) approach was used to compare patients' brain responses before and after EAS at SP6 using REST software. The present study was registered at http://www.chictr.org.cn, and the Clinical Trial Registration Number is ChiCTR-OPC-15005918. Results: EAS at SP6 elicited decreased ReHo value at the bilateral precuneus, right inferior frontal cortex (IFC) and left middle frontal cortex (MFC). In contrast, increased ReHo value was found at the bilateral thalamus, bilateral insula, left putamen and right primary somatosensory cortex (S1). Conclusions: Our study provides an underlying neuroimaging evidence that the aberrant neural activity of PMS patients could be regulated by acupuncture at SP6.

Paeoniflorin, the Main Active Ingredient of Shuyu Capsule, Inhibits Cav1.2 and Regulates Calmodulin/Calmodulin-Dependent Protein Kinase II Signalling

The aim of this study was to explore the mechanism underlying the antidepression activity of paeoniflorin, the main active ingredient of paeony extract and Shuyu capsules, and determine its effect on the calmodulin/calmodulin-dependent protein kinase II (CaM/CaMKII) signalling pathway and on the possible target, the voltage-gated calcium channel (Ca_v). Rats at the nonacceptance stage were selected for premenstrual syndrome (PMS) depression modelling. Behavioural assays were used for model testing. Rats were given Shuyu capsules, paeony extract, and bupleurum. Western blot analysis was used to assess the expression levels of calcium voltage-gated channel subunit alpha 1 C (CACNA1C), brain-derived neurotrophic factor, and CaM/CaMKII signalling pathway proteins. Intracellular Ca²⁺ concentration in CHO cell line was measured using Fluo-4-AM and whole-cell patch clamps. The PMS depression model was successfully established and demonstrated that Shuyu can mitigate depressive behaviour in a rat PMS model. Paeony extract did not affect CACNA1C protein expression in rat hippocampi but did affect Ca_v1.2-mediated CaM/CaMKII signalling pathways. Paeoniflorin significantly inhibited KCl-induced increases in intracellular Ca²⁺ concentration and Ca_v1.2 current density. Further, it may function via the CaM/CaMKII pathway and its downstream signalling molecules by regulating Ca_v1.2, thus playing an important role in the treatment and alleviation of affective disorders.

Altered fractional amplitude of low frequency fluctuation in premenstrual syndrome: A resting state fMRI study

BACKGROUND

Premenstrual syndrome (PMS) is becoming highly prevalent among female and is characterized by emotional, physical and behavior symptoms. Previous evidence suggested functional dysregulation of female brain was expected to be involved in the etiology of PMS. The aim of present study was to evaluate the alterations of spontaneous brain activity in PMS patients based on functional magnetic resonance imaging (fMRI).

METHODS

20 PMS patients and 21 healthy controls underwent resting-state fMRI scanning during luteal phase. All participants were asked to complete a prospective daily record of severity of problems (DRSP) questionnaire.

RESULTS

Compared with healthy controls, the results showed that PMS patients had increased fALFF in bilateral precuneus, left hippocampus and left inferior temporal cortex, and decreased fALFF in bilateral anterior cingulate cortex (ACC) and cerebellum at luteal phase. Moreover, the DRSP scores of PMS patients were negatively correlated with the mean fALFF in ACC and positively correlated with the fALFF in precuneus.

LIMITATIONS

(1) the study did not investigate whether or not abnormal brain activity differences between groups in mid-follicular phase, and within-group changes. between phases.(2) it was relatively limited sample size and the participants were young; (3) fALFF could not provide us with more holistic information of brain network;(4) the comparisons of PMS and premenstrual dysphoric disorder (PMDD) were not involved in the study.

CONCLUSIONS

The present study shows abnormal spontaneous brain activity in PMS patients revealed by fALFF, which could provide neuroimaging evidence to further improve our understanding of the underlying neural mechanism of PMS.

Abnormal Spontaneous Brain Activity in Women with Premenstrual Syndrome Revealed by Regional Homogeneity

Background: Previous studies have revealed that the etiologies of premenstrual syndrome (PMS) refer to menstrual cycle related brain changes. However, its intrinsic neural mechanism is still unclear. The aim of the present study was to assess abnormal spontaneous brain activity and to explicate the intricate neural mechanism of PMS using resting state functional magnetic resonance imaging (RS-fMRI). Materials and Methods: The data of 20 PMS patients (PMS group) and 21 healthy controls (HC group) were analyzed by regional homogeneity (ReHo) method during the late luteal phase of menstrual cycle. In addition, all the participants were asked to complete a daily record of severity of problems (DRSP) questionnaire. Results: Compared with HC group, the results showed that PMS group had increased ReHo mainly in the bilateral precuneus, left inferior temporal cortex (ITC), right inferior frontal cortex (IFC) and left middle frontal cortex (MFC) and decreased ReHo in the right anterior cingulate cortex (ACC) at the luteal phase. Moreover, the PMS group had higher DRSP scores, and the DRSP scores positively correlated with ReHo in left MFC and negatively correlated with ReHo in the right ACC. Conclusion: Our results suggest that abnormal spontaneous brain activity is found in PMS patients and the severity of symptom is specifically related to the left MFC and right ACC. The present findings may be beneficial to explicate the intricate neural mechanism of PMS.

Shuyu Capsules Relieve Premenstrual Syndrome Depression by Reducing 5-HT3AR and 5-HT3BR Expression in the Rat Brain

The effects of the Shuyu capsule on 5-HT_3AR and 5-HT_3BR expression in a rat model of premenstrual syndrome (PMS) depression and on 5-HT_3AR and 5-HT_3BR expression and hippocampal neuron 5-HT₃ channel current were investigated, to elucidate its mechanism of action against PMS depression. PMS depression model rats were divided into depression and Shuyu- and fluoxetine-treated groups, which were compared to control rats for frontal lobe and hippocampal 5-HT_3AR and 5-HT_3BR expression and behavior. The depressed model rats displayed symptoms of depression, which were reduced in treated and normal control rats. Frontal lobe and hippocampal 5-HT_3AR and 5-HT_3BR levels were significantly higher in the model versus the control group and were significantly lower in the Shuyu group. As compared to control rats, the 5-HT₃R channel current in the model group was significantly higher; the 5-HT₃R channel current in hippocampal neurons treated with serum from Shuyu group rats was significantly lower than that in those treated with model group serum. Thus, PMS depression may be related to 5-HT_3AR and 5-HT_3BR expression and increased 5-HT₃ channel current. Shuyu capsules rectified abnormal 5-HT_3AR and 5-HT_3BR expression and 5-HT₃ channel current changes in a rat model; this finding may provide insight into treating PMS depression.

Metabolic profiling of Shu-Yu capsule in rat serum based on metabolic fingerprinting analysis using HPLC-ESI-MSn

The Chinese herbal formula, Shu-Yu capsule (SYC), has been successfully used to treat depression-like disorders in clinical settings. To rapidly identify the chemical constituents of SYC and its metabolites in rat serum, a simple and sensitive liquid chromatography-tandem mass spectrometry method was established in the present study. By comparing the retention times, MS and MSn spectra data in the literature and reference standards, a total of 73 compounds were identified from SYC. In rat serum, 62 components, including 13 prototype compounds and 49 metabolites were identified. Of these components, 14 metabolites were confirmed as novel metabolites of SYC. The results of the present study indicated that certain flavonoid glycosides and monoterpene glycosides were absorbed directly. Glucuronidation and sulfation were identified as the predominant metabolic pathways of the components in SYC. In addition, certain phase I reactions, including hydrolysis, demethylation and hydroxylation occurred in the rats. These results provide scientific evidence, which support further investigations of the pharmacology and mechanism of SYC.