Effects of Liuwei Dihuang decoction on ion channels and synaptic transmission in cultured hippocampal neuron of rat

Mechanisms of multi-omics and network pharmacology to explain traditional chinese medicine for vascular cognitive impairment: A narrative review

BACKGROUND

The term "vascular cognitive impairment" (VCI) describes various cognitive conditions that include vascular elements. It increases the risk of morbidity and mortality in the elderly population and is the most common cognitive impairment associated with cerebrovascular disease. Understanding the etiology of VCI may aid in identifying approaches to target its possible therapy for the condition. Treatment of VCI has focused on vascular risk factors. There are no authorized conventional therapies available right now. The medications used to treat VCI are solely approved for symptomatic relief and are not intended to prevent or slow the development of VCI.

PURPOSE

The function of Chinese medicine in treating VCI has not yet been thoroughly examined. This review evaluates the preclinical and limited clinical evidence to comprehend the "multi-component, multi-target, multi-pathway" mechanism of Traditional Chinese medicine (TCM). It investigates the various multi-omics approaches in the search for the pathological mechanisms of VCI, as well as the new research strategies, in the hopes of supplying supportive evidence for the clinical treatment of VCI.

METHODS

This review used the Preferred Reporting Items for Preferred reporting items for systematic reviews and meta-analyses (PRISMA) statements. Using integrated bioinformatics and network pharmacology approaches, a thorough evaluation and analysis of 25 preclinical studies published up to July 1, 2023, were conducted to shed light on the mechanisms of TCM for vascular cognitive impairment. The studies for the systematic review were located using the following databases: PubMed, Web of Science, Scopus, Cochrane, and ScienceDirect.

RESULTS

We discovered that the multi-omics analysis approach would hasten the discovery of the role of TCM in the treatment of VCI. It will explore components, compounds, targets, and pathways, slowing the progression of VCI from the perspective of inhibiting oxidative stress, stifling neuroinflammation, increasing cerebral blood flow, and inhibiting iron deposition by a variety of molecular mechanisms, which have significant implications for the treatment of VCI.

CONCLUSION

TCM is a valuable tool for developing dementia therapies, and further research is needed to determine how TCM components may affect the operation of the neurovascular unit. There are still some limitations, although several research have offered invaluable resources for searching for possible anti-dementia medicines and treatments. To gain new insights into the molecular mechanisms that precisely modulate the key molecules at different levels during pharmacological interventions-a prerequisite for comprehending the mechanism of action and determining the potential therapeutic value of the drugs-further research should employ more standardized experimental methods as well as more sophisticated science and technology. Given the results of this review, we advocate integrating chemical and biological component analysis approaches in future research on VCI to provide a more full and objective assessment of the standard of TCM. With the help of bioinformatics, a multi-omics analysis approach will hasten the discovery of the role of TCM in the treatment of VCI, which has significant implications for the treatment of VCI.

Traditional uses, phytochemistry, pharmacology, and pharmacokinetics of the root bark of Paeonia x suffruticosa andrews: A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Moutan Cortex (MC), commonly known as "Mu dan pi", refers to the dried root bark of Paeonia x suffruticosa Andrews and is broadly used as a traditional herbal medication in China, Japan, and Korea. For thousands of years, it has been utilized to treat female genital, extravasated blood, cardiovascular, and stagnant blood disorders.

AIM OF THE REVIEW

The purpose of this review article was to summarize information on the traditional uses, phytochemistry, pharmacology and pharmacokinetics of MC, as well as to outline the further research directions for the development of new drugs and the associations between traditional uses and pharmacological effects.

MATERIALS AND METHODS

The information involved in the study was gathered from a variety of electronic resources, including PubMed, Web of Science, ScienceDirect, SciFinder, China Knowledge Resource Integrated Database, and Google Scholar. The date was from 1992 to 2022.

RESULTS

Approximately 163 chemical compounds have been extracted and identified from MC, including monoterpenes, monoterpene glycosides, triterpenes, phenolics, flavonoids, volatile oils, alkaloids, and others. In these categories, the monoterpene glycosides and phenols being the most common. A wide variety of pharmacological effects have been described for MC crude extracts and active molecules, such as antioxidant, anti-inflammatory, antibacterial and antiviral, antitumor, antidiabetic, organ protection, and neuroprotective activities, as well as treating cardiovascular diseases. Pharmacokinetics has been also used in the study of MC, including its crude extracts or chemical constituents, in order to explore the therapeutic mechanism, direct clinically appropriate application and provide new ideas for the exploitation of innovative medicines.

CONCLUSION

Modern pharmacological research has demonstrated that MC, as a significant therapeutic resource, has the ability to heal a wide range of diseases, particularly female genital and cardiovascular problems. These researches propose therapeutic ideas for the development of novel MC medicines. Furthermore, preclinical and clinical study have verified several observed pharmacological properties related with the traditional usages of MC.

Active Fraction Combination From Liuwei Dihuang Decoction Improves Adult Hippocampal Neurogenesis and Neurogenic Microenvironment in Cranially Irradiated Mice

Background: Cranial radiotherapy is clinically used in the treatment of brain tumours; however, the consequent cognitive and emotional dysfunctions seriously impair the life quality of patients. LW-AFC, an active fraction combination extracted from classical traditional Chinese medicine prescription Liuwei Dihuang decoction, can improve cognitive and emotional dysfunctions in many animal models; however, the protective effect of LW-AFC on cranial irradiation–induced cognitive and emotional dysfunctions has not been reported. Recent studies indicate that impairment of adult hippocampal neurogenesis (AHN) and alterations of the neurogenic microenvironment in the hippocampus constitute critical factors in cognitive and emotional dysfunctions following cranial irradiation. Here, our research further investigated the potential protective effects and mechanisms of LW-AFC on cranial irradiation–induced cognitive and emotional dysfunctions in mice.

Methods: LW-AFC (1.6 g/kg) was intragastrically administered to mice for 14 days before cranial irradiation (7 Gy γ-ray). AHN was examined by quantifying the number of proliferative neural stem cells and immature neurons in the dorsal and ventral hippocampus. The contextual fear conditioning test, open field test, and tail suspension test were used to assess cognitive and emotional functions in mice. To detect the change of the neurogenic microenvironment, colorimetry and multiplex bead analysis were performed to measure the level of oxidative stress, neurotrophic and growth factors, and inflammation in the hippocampus.

Results: LW-AFC exerted beneficial effects on the contextual fear memory, anxiety behaviour, and depression behaviour in irradiated mice. Moreover, LW-AFC increased the number of proliferative neural stem cells and immature neurons in the dorsal hippocampus, displaying a regional specificity of neurogenic response. For the neurogenic microenvironment, LW-AFC significantly increased the contents of superoxide dismutase, glutathione peroxidase, glutathione, and catalase and decreased the content of malondialdehyde in the hippocampus of irradiated mice, accompanied by the increase in brain-derived neurotrophic factor, insulin-like growth factor-1, and interleukin-4 content. Together, LW-AFC improved cognitive and emotional dysfunctions, promoted AHN preferentially in the dorsal hippocampus, and ameliorated disturbance in the neurogenic microenvironment in irradiated mice.

Conclusion: LW-AFC ameliorates cranial irradiation–induced cognitive and emotional dysfunctions, and the underlying mechanisms are mediated by promoting AHN in the dorsal hippocampus and improving the neurogenic microenvironment. LW-AFC might be a promising therapeutic agent to treat cognitive and emotional dysfunctions in patients receiving cranial radiotherapy.

A GC-MS-Based Metabolomics Investigation of the Protective Effect of Liu-Wei-Di-Huang-Wan in Type 2 Diabetes Mellitus Mice

Materials and Methods

MKR mice were used for the development of diabetes with high-fat diet feeding. These mice were further injected with streptozocin (STZ) to aggravate kidney failure. Fasting blood glucose (FBG) and urinary albumin-to-creatinine ratio (ACR values) were determined to validate the successful establishment of diabetic models with desired kidney dysfunction. Metabolomics approach coupled with gas chromatography-mass spectrometry (GC-MS) and random forest (RF) algorithm was proposed to discover the metabolic differences among model group and control group as well as to examine the therapeutic efficacy of traditional Chinese medicine, Liu-Wei-Di-Huang-Wan (LWDHW), in diabetes and associated kidney failure.

Results

Some metabolites such as 3-hydroxybutyric acid, citric acid, hexadecanoic acid, and octadecanoic acid showed significant differences between the control group and model group. Treatment with LWDHW resulted in a significant decrease in FBG and ACR values. These results suggested that LWDHW could have beneficial effects in diabetes-associated renal failure.

Liuwei Dihuang prevents postmenopausal atherosclerosis and endothelial cell apoptosis via inhibiting DNMT1-medicated ERα methylation

ETHNOPHARMACOLOGICAL RELEVANCE

The classical and traditional Chinese medicine prescription, Liuwei Dihuang (LWDH), has been commonly used to treat the menopausal syndrome. It has been reported that LWDH could improve estrogen receptor α (ERα) expression to prevent atherosclerosis (AS), while the mechanism of LWDH on regulating ERα expression was still unknown.

AIM OF THE STUDY

To reveal the mechanism of LWDH on regulating the ERα expression.

MATERIALS AND METHODS

The protective effect of LWDH on Hcy-induced apoptosis of human umbilical vein endothelial cells (HUVECs) was examined. The expression of ERα and DNA methyltransferases 1 (DNMT1) were detected by Western blot and real-time polymerase chain reaction (RT-PCR). The methylation rate of the ERα gene was assayed by the bisulfite sequencing PCR (BSP). High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS) was applied to determine the level of S-Adenosyl methionine (SAM) and S-Adenosyl homocysteine (SAH). In vivo, the ApoE^-/- mice were ovariectomized to establish postmenopausal atherosclerosis (AS) model.

RESULTS

In vitro study showed that LWDH protects HUVECs from Hcy-induced apoptosis. Treatment with LWDH significantly increased the ERα expression and reduced the methylation rate of the ERα gene by inhibiting the DNMT1 expression. The level of main methyl donor SAM and the ration of SAM/SAH were reduced by LWDH. In vivo, LWDH prevented the formation of plaque and reduced the concentration of Hcy. In addition, LWDH upregulated the ERα expression, as well as inhibiting the expression of DNMT1 in atherosclerotic mice.

CONCLUSIONS

LWDH exerted protective effects on postmenopausal AS mice, and HUVECs treated with Hcy. LWDH increased of ERα expression via inhibiting DNMT1-dependent ERα methylation.

Liuwei Dihuang Pills alleviate the polycystic ovary syndrome with improved insulin sensitivity through PI3K/Akt signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Polycystic ovary syndrome (PCOS) is a complex gynecological endocrine disease commonly occurred in women of childbearing age. The main hallmark of PCOS includes elevated androgen production and insulin resistance (IR). Liuwei Dihuang Pills (LWDH Pills), a commonly prescribed traditional Chinese medicine (TCM) is widely used as a tonic prescription to treat diabetes, female menopause syndrome and other symptoms with'Kidney-Yin' deficiency. It has been reported the effects LWDH pills on PI3K/Akt signaling pathway in T2DM treatment. Recent studies have also indicated that the treatment of menopausal syndrome may be associated with the ovarian sexual hormone levels regulated by LWDH pills to alleviate female infertility. However, its potential benefits on PCOS have not been fully elucidated.

AIM OF THE STUDY

The primary aim of this study was to investigate the alterations of PI3K/Akt pathway in polycystic ovary syndrome-insulin resistance (PCOS-IR) progression induced by letrozole combined with high fat diet (HFD) and then to explore the detailed mechanism of LWDH Pills to alleviate PCOS.

MATERIALS AND METHODS

The female Sprague-Dawley rats were continuously treated with letrozole (p.o administration at 1 mg kg^-1·day^-1) and HFD for 21 days to establish the PCOS-IR model. Concurrently, metformin (200 mg kg^-1·day^-1) or LWDH Pills was orally administrated (1.2 or 3.6 g kg^-1·day^-1) to intervene disease progression. The ovarian pathology was evaluated by HE (hematoxylin-eosin) staining. The serum sexual hormones, follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, testosterone, progesterone and fasting insulin (FINS) were determined by radioimmunoassay. The protein expressions of IRS-1, PI3Kp85α, Akt and FoxO1a were analyzed by western blotting, while the mRNA levels of follicle-stimulating hormone receptor (FSHR) and Cyp19a1 in ovarian tissue were measured by qPCR.

RESULTS

The upregulated phosphorylation of IRS-1 (S307), down-regulated phosphorylation of PI3Kp85α, Akt, and FoxO1a were significantly reversed by LWDH Pills (3.6 g kg^-1·day^-1) in PCOS-IR rats with up-regulated mRNA levels of FSHR and Cyp19a1 in ovary. Also, the index of insulin resistance was gradually adjusted to normal by LWDH Pills. The serum levels of FSH, estradiol, progesterone levels were significantly raised while LH, testosterone were reduced. The ovarian polycystic changes were alleviated while the atresia follicles were reduced.

CONCLUSION

LWDH Pills therapy obviously improved the ovarian polycystic pathogenesis and regained the development of follicles via upregulating Cyp19a1, alleviated insulin resistance through acting on PI3K/Akt signaling pathway. These findings have provided scientific evidence for LWDH Pills to treat PCOS.

LW-AFC, a new formula from the traditional Chinese medicine Liuwei Dihuang decoction, as a promising therapy for Alzheimer's disease: Pharmacological effects and mechanisms

LW-AFC is a new formula derived from the Liuwei Dihuang decoction, a classical traditional Chinese medicine prescription. Based on our research, LW-AFC is a promising drug for Alzheimer's disease (AD). The studies were conducted primarily in two typical AD mouse models: SAMP8 and APP/PS1 mice. The results showed that LW-AFC could improve many cognitive behaviors, such as spatial learning and memory ability, passive and active avoidance response, and object recognition memory capability. In addition, LW-AFC could also alleviate the AD-like pathology in animal models, such as neuron loss and Aβ deposition. Subsequent studies found that LW-AFC could rebalance hypothalamic-pituitary-adrenal (HPA) axis and hypothalamic-pituitary-gonadal (HPG) axis, and modulate the disturbance of immune system and gut flora. These data suggested that the anti-AD effects of LW-AFC might be mainly via modulating the neuroendocrine immunomodulation (NIM) network. As inhibiting the immune function by immunosuppressant could abolish the protective effects of LW-AFC against long-term potentiation (LTP) impairment model, it is likely that LW-AFC balancing the NIM network is initiated by modulating the immune system.

Liuwei Dihuang, a traditional Chinese medicinal formula, inhibits proliferation and migration of vascular smooth muscle cells via modulation of estrogen receptors

The phenotypic modulation of vascular smooth muscle cells (VSMCs) serves an important role in atherosclerosis-induced vascular alterations, including vascular remodeling. However, the precise mechanisms underlying VSMC phenotypic modulation remain to be elucidated. Our previous study demonstrated that Liuwei Dihuang formula (LWDHF) could improve menopausal atherosclerosis by upregulating the expression of estrogen receptors (ERs). The present study examined the role of ERs in the effects of LWDHF on VSMC phenotypic modulation. VSMC proliferation and cell cycle progression were examined by MTT assay and flow cytometry, respectively. The expression levels of α-smooth muscle actin, osteopontin and ERs were determined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. Cell ultrastructure was observed under an electron microscope. F-actin polymerization was detected by fluorescein isothiocyanate-phalloidin staining using fluorescence microscopy. A modified Boyden chamber assay was employed to assess VSMCs migration. Small interfering (si)RNA technology was used to examine the role of ERα in the effects of LWDHF on phenotypic modulation. The results indicated that LWDHF (3-12 µg/ml) inhibited proliferation and induced a cell cycle arrest in VSMCs treated with angiotensin II (Ang II; 100 nM) in a concentration-dependent manner. In addition, Ang II-stimulated migration of VSMCs and reorganization of actin were markedly inhibited by treatment with 12 µg/ml LWDHF. Results of RT-qPCR and western blotting demonstrated that LWDHF markedly stimulated transcription and expression of ERα and ERβ, and inhibited VSMC synthetic phenotype. Furthermore, LWDHF-induced inhibition of phenotypic switching was partially suppressed by tamoxifen, and transfection with ERα siRNA markedly abolished the effects of LWDHF on VSMC phenotypic switching. In conclusion, these results revealed that ERα served an important role in LWDHF-induced regulation of the VSMC phenotype, including proliferation and migration.

Simultaneous determination of organochlorine and pyrethriod pesticide residues in the Chinese patent medicines by gas chromatography-tandem mass spectrometry

A simple, sensitive, reliable method was developed for the simultaneous determination of organochlorine and pyrethriod pesticide residues in Chinese patent medicines Six ingredient rehmannia pills and Xiaoyao pills. These pesticides were extracted by ethyl acetate. The extraction time and volume of ethyl acetate were optimized. Cleanup of extracts was performed with dispersive-solid phase extraction using graphitized carbon black as the sorbent. The determination of pesticides in the final extracts was carried out by gas chromatography-tandem mass spectrometry in multiple reaction monitoring mode (GC-MS/MS, MRM). The linearity of the calibration curves is good in matrix-matched standard and yields the coefficients of determination (R²) ≥0.99 for all of the target analytes. Under optimized conditions, the average recoveries (five replicates) for most pesticides range from 75.5% to 114.6%, and RSDs are less than 10.0%. The LODs of 18 pesticides in Six ingredient rehmannia pill and Xiaoyao pills are in the range of 0.01-8.82 μg kg^-1. The developed method meets the requirements of pesticide residue analysis and could be effectively used for routine analysis of the organochlorine and pyrethriod pesticide residues in Six ingredient rehmannia pills and Xiaoyao pills.

Liuwei Dihuang soft capsules attenuates endothelial cell apoptosis to prevent atherosclerosis through GPR30-mediated regulation in ovariectomized ApoE-deficient mice

ETHNOPHARMACOLOGICAL RELEVANCE

Liuwei Dihuang (LWDH), a classical traditional Chinese medicine prescription, has been widely used to prevent and to treat various diseases with symptoms of 'Kidney-Yin' deficiency syndrome for over 1000 years in China. It is commonly used to treat functional decline associated with senile disease and menopausal syndrome, especially memory decline, insomnia, diabetes and osteoporosis. Modern experimental pharmacological studies indicated that the mechanism of LWDH treatment of menopausal syndrome may be associated with enhanced estrogenic effects. However, little attention has been paid to the potential impact of LWDH on atherosclerosis (AS) associated with female menopause. The aim of this study was to evaluate the preventive effects of LWDH intake on an animal model of female menopause AS and to explore the underlying molecular mechanism.

MATERIALS AND METHODS

ApoE^-/- mice were randomly divided into 4 groups, with C57BN/L6 mice as the control group. All ApoE^-/- mice were ovariectomized (Ovx) one week prior to oral administration and initiation of high-fat diet. C57BL/6 mice were given sham operation and maintained on normal diet. The three administered groups were given simvastatin (4mg/kg via i.g.) and LWDH (4.5, 9.0g/kg via i.g.) every day for 14 weeks. Atherosclerotic lesions in the aortic root were determined by oil red O staining and hematoxylin-eosin staining. α-Actin and CD68 in atherosclerotic lesions were detected by immunohistological assay. Serum lipids and homocysteine (Hcy) levels were measured in the 14th week. The cleaved caspase-3, C/EBP homologous protein (CHOP) and G protein coupled estrogen receptor 30 (GPR30) expressions in the aortic arch endothelium were determined by immunohistochemistry and Western blot. The inhibitory effect of LWDH-medicated (20%, 12h) on Hcy (20%, 24h)-induced apoptosis of human umbilical vein endothelial cells (HUVECs) was examined by flow cytometry and Hoechst 33258 staining. Intracellular ROS production, nitric oxide release, and endothelial NO synthase (eNOS) activity were measured with or without LWDH-medicated serum pretreatment. In addition, CHOP, glucose-regulated protein GPR30, 78 (Grp78), Bcl-2, Bax and cleaved caspase-3 were analyzed by Western blot. Finally, the influence of G15, a specific antagonist of GPR30, on the protective effect of LWDH on endothelial cells was investigated.

RESULTS

In vivo administration of LWDH prevented plaque formation and reduced plasma lipid and Hcy levels. LWDH inhibited CHOP and cleaved caspase-3 expression in vivo and in vitro while maintaining GPR30 expression. In vitro study showed that Hcy-induced HUVECs apoptosis was weakened by LWDH-medicated serum pretreatment. Treatment with LWDH-medicated serum significantly upregulated NO release and eNOS activity in HUVECs. In addition, LWDH-medicated serum treatment optimized the balance between Bax and Bcl-2, and attenuated intracellular ROS production. G15 reversed the protective effect of LWDH on endothelial cells and the changes of apoptosis-related proteins.

CONCLUSIONS

LWDH treatment can significantly reduce plaque formation in an animal model of menopausal AS. The mechanism may be inhibition of Hcy-induced endothelial cell apoptosis by modulating GPR30. Hence, LWDH can potentially be used to prevent AS-related vascular disease in menopausal women.

TREK1 channel blockade induces an antidepressant-like response synergizing with 5-HT1A receptor signaling

Current antidepressants often remain the inadequate efficacy for many depressive patients, which warrant the necessary endeavor to develop the new molecules and targets for treating depression. Recently, the two-pore domain potassium channel TREK1 has been implicated in mood regulation and TREK-1 antagonists could be the promising antidepressant. This study has screened a TREK1 blocker (SID1900) with a satisfactory blood-brain barrier permeation and bioavailability. Electrophysiological research has shown that SID1900 and the previously reported TREK1 blocker (spadin) efficiently blocked TREK-1 current in HEK293 cells and specifically blocked two-pore domain potassium channels in primary-cultured rat hippocampal neurons. SID1900 and spadin induced a significant antidepressant-like response in the rat model of chronic unpredictable mild stress (CUMS). Both two TREK1 blockers substantially increased the firing rate of 5-HT-ergic neurons in the dorsal raphe nuclei (DRN) and PFC of CUMS rats. SID1900 and spadin significantly up-regulated the expression of PKA-pCREB-BDNF signaling in DRN, hippocampus and PFC of CUMS rats, which were enhanced and reversed by a 5-HTR1A agonist (8-OH-DPAT) and antagonist (WAY100635) respectively. The present findings suggested that TREK1 channel blockers posses the substantial antidepressant-like effect and have the potential synergistic effect with 5-HT1A receptor activation through the common CREB-BDNF signal transduction.

Aiweixin, a traditional Uyghur medicinal formula, protects against chromium toxicity in Caenorhabditis elegans

Background

Aiweixin (AWX) is a traditional Uyghur medicine prescription, and has been mainly used to treat heart and brain diseases for a long time. Previous studies indicated that AWX had therapeutic effects in a rat model of myocardial ischemia reperfusion injury. In this study, we investigate whether AWX has protective effects against chromium toxicity in Caenorhabditis elegans (C. elegans).

Methods

The AWX decoction was the conventional product for clinical use. It was added into M9 buffer in a certain volume for the treatment to the wild-type C. elegans and mutational worms, daf-16, glp-1(notch), daf-2, rsks-1 and eat-2. Assays for hexavalent chromium {Cr(VI)} stress and reactive oxygen species (ROS) production were used.

Results

We found that AWX at moderate contents (0.083, 0.1, 0.125 volume of AWX/total volume) increased resistance of C. elegans to Cr(VI) exposure, although higher contents of AWX are toxic for C. elegans. The protective effect of AWX was DAF-16-dependent, but independent on the DAF-2, GLP-1, RSKS-1 and EAT-2. AWX (0.1 volume of AWX/total volume) significantly reduced ROS production of C. elegans induced by Cr(VI) exposure.

Conclusion

These results indicated the AWX protected against the toxicity of Cr(VI) in C. elegans, and the oxidative stress protective mechanism in worms should be involved.

Neuropeptide Y protects cerebral cortical neurons by regulating microglial immune function

Neuropeptide Y has been shown to inhibit the immunological activity of reactive microglia in the rat cerebral cortex, to reduce N-methyl-D-aspartate current (I_NMDA) in cortical neurons, and protect neurons. In this study, after primary cultured microglia from the cerebral cortex of rats were treated with lipopolysaccharide, interleukin-1β and tumor necrosis factor-α levels in the cell culture medium increased, and mRNA expression of these cytokines also increased. After primary cultured cortical neurons were incubated with the lipopolysaccharide-treated microglial conditioned medium, peak I_NMDA in neurons increased. These effects of lipopolysaccharide were suppressed by neuropeptide Y. After addition of the neuropeptide Y Y1 receptor antagonist BIBP3226, the effects of neuropeptide Y completely disappeared. These results suggest that neuropeptide Y prevents excessive production of interleukin-1β and tumor necrosis factor-α by inhibiting microglial reactivity. This reduces I_NMDA in rat cortical neurons, preventing excitotoxicity, thereby protecting neurons.

The effects of Liuwei Dihuang on canonical Wnt/β-catenin signaling pathway in osteoporosis

ETHNOPHARMACOLOGICAL RELEVANCE

The Liuwei Dihuang (LWDH), a wellknown classic traditional Chinese medicine formula, consists of six herbs including Rehmannia glutinosa Libosch. (family: Scrophulariaceae), Cornus officinalis Sieb. (family: Cornaceae), Dioscorea opposite Thunb. (family: Dioscoreaceae), Alisma orientale (G. Samuelsson) Juz (family: Alismataceae), Poria cocos (Schw.) Wolf (family: Polyporaceae) and Paeonia suffruticosa Andrews (family: Paeoniaceae). It has been used clinically in the treatment of many types of diseases with signs of deficiency of Yin in the kidneys for more than 1000 years in China. The purpose of this study was to observe the effects of LWDH on canonical Wnt/β-catenin signaling pathway in osteoporosis.

MATERIALS AND METHODS

Osteoporosis model was induced by ovariectomy (OVX) in 8-week-old female Sprague-Dawley (SD) rats. After 12 weeks of treatment with LWDH by intragastric administration, the rats were put to death in batch. The changes of alkaline phosphatase (ALP), osteocalcin (BGP) and estradiol (E2) in serum were determined, bone mineral density (BMD) and histomorphology of right femur were observed, biomechanics of lumbar vertebra were measured, and the expression of Lrp-5, β-catenin, Runx2, Osx involving the canonical Wnt/β-catenin signaling pathway were detected by RT-PCR. In addition, osteoblasts isolated from neonatal rat calvariae were used in this study to investigate the effects of LWDH on the canonical Wnt/β-catenin signaling pathway. Cell proliferation and differentiation were observed by the MTT test, ALP activity and calcified nodules. The expression of Lrp-5, β-catenin, Runx2, Osx mRNA of cells were also detected. All the data were analyzed by SPSS 13.0.

RESULTS

Twelve weeks of treatment with LWDH could significantly decrease the level of ALP and BGP in serum, increase the BMD of femurs, and improve the biomechanical capabililty of vertebral body in maximum loading and elastic modulus. Concerning histomorphology, we found ordered arrangement of trabeculae, slightly thinning of trabeculae and none obvious slight fractures in femurs after twelve weeks of treatment with LWDH. In osteoblast, serum containing LWDH elicited significantly increase in cell viability (at day 6), alkaline phosphatase activity (at days 2, 4 and 6) and amount of calcified nodules. The expression of Lrp-5, β-catenin, Runx2 and Osx involved in the canonical Wnt/β-catenin signaling pathway were significantly up-regulated in the presence of LWDH both in vivo and in vitro experiment.

CONCLUSIONS

Our results suggest that Liuwei Dihuang could alleviate osteoporosis induced by ovariectomy, in part, through up-regulation of canonical Wnt/β-catenin signaling pathway of osteoblast.

Neuroprotective effect of Liuwei Dihuang decoction on cognition deficits of diabetic encephalopathy in streptozotocin-induced diabetic rat

ETHNOPHARMACOLOGICAL RELEVANCE

Liuwei Dihuang decoction (LWDHD) is a well-known prescription of traditional Chinese medicine (TCM) and consists of six crude drugs including Rehmannia glutinosa Libosch. (family: Scrophulariaceae), Cornus officinalis Sieb. (family: Cornaceae), Dioscorea oppositifolia L. (family: Dioscoreaceae), Paoenia ostii (family: Paeoniaceae), Alisma orientale (G. Samuelsson) Juz (family: Alismataceae) and Poria cocos (Schw.) Wolf (family: Polyporaceae). It has been used for the treatment of "Kidney-Yin" deficiency syndrome in clinic in China for a long time. Recent studies found that LWDHD had a potential benefit for the treatment of diabetic complications. The aim of the present study is to investigate the neuroprotective effect of LWDHD on memory and cognition deficits in streptozotocin (STZ)-induced diabetic encephalopathy (DE) rats.

MATERIALS AND METHODS

Adult male Sprague Dawley (SD) rats were fed with high-glucose-fat diet for 50 days and then received an intraperitoneal injection of STZ (40 mg/kg) to induce DE model. Morris water maze test was used to evaluate the memory and cognition capability of DE rats. Choline acetyltransferase (ChAT), acetylcholinesterase (AChE), Na(+)-K(+)-ATP enzyme, iNOS and GSH kits were used to determine their activities or content in hippocampus. TUNEL staining, immunohistochemistry and Congo red staining were conducted to evaluate the apoptosis, caspase-3 protein expression, insulin-like growth factors 1 (IGF-1) and brain derived neurophic factor (BDNF) expressions, as well as Aβ deposition.

RESULTS

The treatment with LWDHD (1 and 2g/kg, p.o., once daily, 30 days) could significantly reduce the escape latency time and path length, and obviously enhance the spent time in the target quadrant and platform crossings in Morris water maze test compared with model group (P<0.05, P<0.01). LWDHD could also significantly decrease the level of fasting blood glucose, increase Na(+)-K(+)-ATP enzyme and ChAT activities, enhance remarkedly GSH level while decrease significantly AChE and iNOS activities in hippocampus (P<0.05, P<0.01). Furthermore, TUNEL staining, Congo red staining and immunohistochemistry showed that LWDHD significantly improved the expressions of IGF-1 and BDNF, attenuated the neural apoptosis, overexpression of caspase-3 and Aβ deposition in the hippocampus and cerebral cortex of STZ-induced DE rats (P<0.01).

CONCLUSION

Our findings suggested that LWDHD had a neuroprotective effect on DE rats. LWDHD may be of benefit in the treatment of DE.

Liuwei Dihuang (LWDH), a traditional Chinese medicinal formula, protects against β-amyloid toxicity in transgenic Caenorhabditis elegans

Liuwei Dihuang (LWDH), a classic Chinese medicinal formula, has been used to improve or restore declined functions related to aging and geriatric diseases, such as impaired mobility, vision, hearing, cognition and memory. Here, we report on the effect and possible mechanisms of LWDH mediated protection of β-amyloid (Aβ) induced paralysis in Caenorhabditis elegans using ethanol extract (LWDH-EE) and water extract (LWDH-WE). Chemical profiling and quantitative analysis revealed the presence of different levels of bioactive components in these extracts. LWDH-WE was rich in polar components such as monosaccharide dimers and trimers, whereas LWDH-EE was enriched in terms of phenolic compounds such as gallic acid and paeonol. In vitro studies revealed higher DPPH radical scavenging activity for LWDH-EE as compared to that found for LWDH-WE. Neither LWDH-EE nor LWDH-WE were effective in inhibiting aggregation of Aβ in vitro. By contrast, LWDH-EE effectively delayed Aβ induced paralysis in the transgenic C. elegans (CL4176) model which expresses human Aβ1–42. Western blot revealed no treatment induced reduction in Aβ accumulation in CL4176 although a significant reduction was observed at an early stage with respect to β-amyloid deposition in C. elegans strain CL2006 which constitutively expresses human Aβ1–42. In addition, LWDH-EE reduced in vivo reactive oxygen species (ROS) in C. elegans (CL4176) that correlated with increased survival of LWDH-EE treated N2 worms under juglone-induced oxidative stress. Analysis with GFP reporter strain TJ375 revealed increased expression of hsp16.2::GFP after thermal stress whereas a minute induction was observed for sod3::GFP. Quantitative gene expression analysis revealed that LWDH-EE repressed the expression of amy1 in CL4176 while up-regulating hsp16.2 induced by elevating temperature. Taken together, these results suggest that LWDH extracts, particularly LWDH-EE, alleviated β-amyloid induced toxicity, in part, through up-regulation of heat shock protein, antioxidant activity and reduced ROS in C. elegans.

Liuwei Dihuang decoction facilitates the induction of long-term potentiation (LTP) in senescence accelerated mouse/prone 8 (SAMP8) hippocampal slices by inhibiting voltage-dependent calcium channels (VDCCs) and promoting N-methyl-d-aspartate receptor (NMDA) receptors

ETHNOPHARMACOLOGICAL RELEVANCE

Liuwei Dihuang decoction (LW) is a typical traditional Chinese medicine (TCM) prescription and consists of six herbs including Rehmannia glutinosa Libosch. (family: Scrophulariaceae), Cornus officinalis Sieb. (family: Cornaceae), Dioscorea opposite Thunb. (family: Dioscoreaceae), Alisma orientale (G. Samuelsson) Juz (family: Alismataceae), Poria cocos (Schw.)Wolf (family: Polyporaceae) and Paeonia suffruticosa Andrews (family: Paeoniaceae). It has long been used clinically in treatment of many kinds of diseases with the sign of Yin insufficiency of kidney.

AIM OF THE STUDY

Our previous pharmacological studies demonstrated that LW possesses effect of ameliorating the decline of the learning and memory in senescence accelerated mouse/prone 8 (SAMP8), but the mechanism has not been well established. LW-containing serum (LWCS) is used in the current study to elucidate the possible mechanisms.

MATERIALS AND METHODS

6-month-old SAMP8 was used in this study to investigate the effect of LWCS on the induction of long-term potentiation (LTP). Primary cultured hippocampal neurons were used in this study to investigate the effects of LWCS on [Ca(2+)](i), I(Ca) and N-Methyl-d-aspartate (NMDA)-evoked currents. [Ca(2+)](i) was imaged using Fluo-3 and whole-cell patch recordings were applied to study the I(Ca) and NMDA-evoked currents.

RESULTS

We find that LWCS facilitates the induction of LTP in hippocampal slices of 6-month-old SAMP8. In primary cultured hippocampal neurons, LWCS increases intracellular [Ca(2+)](i), the I(Ca) is suppressed by LWCS, and NMDA-evoked currents are promoted.

CONCLUSION

These results indicate that LW improves the synaptic plasticity by inhibiting voltage-dependent calciumchannels (VDCCs) and promoting the function of NMDA receptors. This improvement might be one of the mechanisms contributing to cognitive improvement effect of LW.

Autocrine motility factor receptor is involved in the process of learning and memory in the central nervous system

The autocrine motility factor receptor (AMFR) is a multifunctional protein involved in cellular adhesion, proliferation, motility and apoptosis. Our study showed that increased AMFR protein expression in the hippocampus of KM mice correlated with enhanced capacity for learning and memory following the shuttle-box test and was significantly elevated in the highest score group. Also, AMF and AMFR mRNA expression positively correlates with the mRNA expression of the synapse marker synaptophysin (Syp). Aging studies in the senescence-accelerated mouse strain (SAM) prone/8 (SAMP8), an animal model of Alzheimer's disease (AD), revealed significantly decreased mRNA and protein expression of AMF and AMFR in the hippocampus. This is especially true for AMFR and AMF protein expression compared with age-matched SAM resistant/1 (SAMR1) mouse strain as the control. Additionally, the low mRNA expression of AMFR could be up-regulated by the four nootropic traditional Chinese medicinal prescriptions (TCMPs): Ba-Wei-Di-Huang decoction (BW), Huang-Lian-Jie-Du decoction (HL), Dang-Gui-Shao-Yao-San (DSS) and Tiao-Xin-Fang decoction (TXF). AMFR protein expression could be up-regulated by two TCMPs, Liu-Wei-Di-Huang decoction (LW) and BW. This indicated that AMFR is involved in the process of learning and memory in the central nervous system. These results may provide useful clues for understanding the etiology of AD.

Assessing the microcirculatory response following oral administration of Liuwei Dihuang formula by spectral analysis of skin-surface laser Doppler signals

OBJECTIVE

This study aimed to assess the skin-surface microcirculatory effects of oral administration of Liuwei Dihuang (LW) formula by analyzing the frequency content of laser-Doppler skin blood-flow signals at important acupoints.

METHODS

Laser-Doppler signals were measured in male healthy volunteers in two groups of experiments: the LW experiment (n=42; aged (27.8±3.8) years) and the control experiment (n=28; aged (27.3±3.4) years). Each experiment involved a 20-minute baseline-data sequence and three following sets of effects data: recorded on the same day after oral administration of 250 mL water (28 degrees centigrade) accompanied with 5 g of LW formula (herbal extract granules), and recorded on the second day after taking other two doses of LW formula.

RESULTS

During the second day, the increases in the mean and pulsatile components of the flux signal were the most prominent, and the relative energy contribution at 0.02 to 0.06 Hz was significantly decreased at Taixi (KI3). There were no any other significant changes in these parameters at other measurement sites.

CONCLUSION

The redistribution of skin-surface microcirculatory blood flow following oral LW administration observed here can be attributed to different changes in sympathetic neural activities and thus the different perfusion resistance through the arteriolar openings of the peripheral vascular beds at different measurement sites. The developed noninvasive and real-time monitoring technique could form part of an evidence-based method for studying the physiological effects and the underlying mechanisms of traditional Chinese medicine herbs.

Review of the effects of the traditional Chinese medicine Rehmannia Six Formula on diabetes mellitus and its complications

Rehmannia Six Formula (RF) is a formula that is commonly used in Traditional Chinese Medicine to treat patients with diabetes. A literature search was performed in PubMed for the years 2000-2009 using the key words RF, Rehmannia glutinosa, Fructus Corni, Dioscorea sp. (D. alata, D. opposita, D. batatas), Poria cocos, Alisma sp. (A. orientalis, A. plantago aquatica), and Paeonia suffruticosa/Cortex Moutan. On the basis of the publications found, RF appears to have beneficial effects on blood glucose, neuropathy, and nephropathy. There is also evidence of anti-inflammatory and antioxidant effects. Although there are many studies on compounds extracted from individual herbs, there are not many studies on RF as a whole. Because there is preliminary evidence that RF may be a useful supplement for the prevention of diabetic complications, clinical studies are warranted. For future clinical studies, it is recommended that details are provided regarding the preparation of RF and that the ratio of the individual components in RF is standardized so that results across studies can be compared.

Potential role of metabolomics apporoaches in the area of traditional Chinese medicine: as pillars of the bridge between Chinese and Western medicine

Traditional Chinese medicine (TCM) is a holistic approach to health that attempts to bring the body, mind and spirit into harmony. Entering 21st century, TCM is getting more and more popular in the whole world for improving health condition of human beings and preventing or healing diseases, especially shows great advantages in early intervention, combination therapies and personalized medicine, etc. However, like almost all other ethnopharmacology, TCM also faces severe challenges and suffers from insufficient modern research owing to lack of scientific and technologic approaches, restricts the development of TCM in the world. Fortunately, a novel analytical technique, metabolomics (or metabonomics), adopts a 'top-down' strategy to reflect the function of organisms from terminal symptoms of metabolic network and understand metabolic changes of a complete system caused by interventions in holistic context. Its property consists with the holistic thinking of TCM, may beneficially provide an opportunity to scientifically express the meaning of evidence-based Chinese medicine, such as Chinese medicine syndromes (CMS), preventive treatment, action of Chinese medicine, Chinese medical formulae (CMF) and acupuncture efficacy. This review summarizes potential applications of robust metabolomics apporoaches in the area of traditional oriental medicine, and highlights the key role of metabolomics to resolve special TCM issues.

Excitotoxicity of TNFalpha derived from KA activated microglia on hippocampal neurons in vitro and in vivo

Highly activated microglia and followed excessive expression of inflammatory cytokines are associated with neuroexcitotoxic injuries. We use electrophysiological techniques, ELISA, western-blot, RT-PCR assay and TUNEL method to explore whether over-produced tumor necrosis factor alpha (TNFalpha) released from activated microglia results in neuronal injuries, and further causes apoptosis through increasing excitotoxicity of hippocampal neurons. Our data showed that kainic acid (KA) activated microglia highly expressed TNFalpha, mRNA and protein. KA activated microglia conditioned media ((KA-MCM) significantly enhanced the amplitude of the population spike at rat's hippocampal CA3 region. It also increased the Ca(2+) current amplitude and density in cultured hippocampal neurons, as well as the high expression of NMDAR1, iNOS, and caspase 3 mRNA and protein at both hippocampal neurons and tissues. KA-MCM also increased TUNEL-positive cells in hippocampal neurons, whereas addition of anti-TNFalpha to the KA-MCM before its application significantly reduced those effects. These studies suggest that TNFalpha derived from KA activated microglia increases excitotoxicity of hippocampal neurons, and might induce neuronal apoptosis in vitro and in vivo.

Rehmannia glutinosa: review of botany, chemistry and pharmacology

Rehmannia glutinosa, a widely used traditional Chinese herb, belongs to the family of Scrophulariaceae, and is taken to nourish Yin and invigorate the kidney in traditional Chinese medicine (TCM) and has a very high medicinal value. In recent decades, a great number of chemical and pharmacological studies have been done on Rehmannia glutinosa. More than 70 compounds including iridoids, saccharides, amino acid, inorganic ions, as well as other trace elements have been found in the herb. Studies show that Rehmannia glutinosa and its active principles possess wide pharmacological actions on the blood system, immune system, endocrine system, cardiovascular system and the nervous system. Currently, the effective monomeric compounds or active parts have been screened for the pharmacological activity of Rehmannia glutinosa and the highest quality scientific data is delivered to support the further application and exploitation for new drug development.

The ameliorating effects of LiuWei Dihuang Wang on cycloheximide-induced impairment of passive avoidance performance in rats

The ameliorating effects of aqueous and ethanolic extracts of LiuWei Dihuang Wang (LDW(W) and LDW(E)) after single, 1-week or 2-week consecutive treatment on the cycloheximide-induced amnesia by using the passive avoidance task in rats were studied. After single treatment, LDW(W) and LDW(E) (1 and 2g/kg) significantly prolonged the shortened step-through latency induced by CXM and their potency was equal. LDW(W) at 1g/kg after 1-week consecutive treatment or at 0.1g/kg after 2-week consecutive treatment almost completely reversed CXM-induced amnesia. LDW(W) at any dose alone after single, 1-week or 2-week consecutive treatment did not influence the step-through latency in the training trial in rats. Furthermore, muscarinic antagonist scopolamine, peripheral cholinergic antagonist scopolamine methylbromide, serotonin precursor 5-hydroxytryptamine and serotonin releaser p-chloroamphetamine could block the ameliorating effects of LDW(W). GABA(A) receptor antagonist bicuculline and GABA(B) receptor agonist baclofen also blocked the ameliorating effects of LDW(W). These results suggest that the ameliorating effects of LDW whose potency were parallel to treatment duration might be related to activating peripheral cholinergic neuronal system and modulating the central nervous system.