Scutellaria Baicalensis Georgi Stem and Leaf Flavonoids Ameliorate the Learning and Memory Impairment in Rats Induced by Okadaic Acid.

AIM: The objective of this study is to explore the impact and underlying mechanism of Scutellaria baicalensis Georgi stem and leaf flavonoids (SSFs) on cognitive impairment caused by intracerebroventricular injection of okadaic acid (OA) in rats. METHODS: An experimental model of Alzheimer's disease (AD) was induced in rats by intracerebroventricular injection of OA, resulting in memory impairment. The Morris water maze test was employed to confirm the successful establishment of the memory impairment model. The rats that exhibited significant memory impairment were randomly divided into different groups, including a model group, three SSFs dose groups (25, 50, and 100 mg/kg), and a positive control group treated with Ginkgo biloba tablets (GLT) at a dose of 200 mg/kg. To evaluate the learning and memory abilities of the rats, the Morris water maze test was conducted. Hematoxylin-eosin (HE) staining was used to observe any morphological changes in neurons. Immunohistochemistry (IHC) was performed to measure the expression of choline acetyltransferase (ChAT) protein. Western blotting (WB) was utilized to assess the phosphorylation levels of tau protein at Ser262 and Ser396. The activities of inducible nitric oxide synthase (iNOS) and constitutive nitric oxide synthase (cNOS) were quantified using ultraviolet spectrophotometry. The levels of inflammatory factors, including interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6), were measured using ELISA. RESULTS: In rats, the administration of OA via intracerebroventricular injection resulted in cognitive impairment, neuropathological changes, and alterations in protein expression and activity levels. Specifically, the protein expression of ChAT was significantly reduced (P<0.01), while the phosphorylation levels of tau protein at Ser262 and Ser396 were significantly increased (P<0.01). Moreover, iNOS activity in the hippocampus and cerebral cortex exhibited a significant increase (P<0.01), whereas cNOS activity showed a decrease (P<0.05). Furthermore, the levels of IL-1ß and TNF-α in the cerebral cortex were elevated (P<0.01), while the level of IL-6 was decreased (P<0.05). The administration of three doses of SSFs and GLT to rats exhibited varying degrees of improvement in the aforementioned pathological alterations induced by OA. CONCLUSION: SSFs demonstrated the ability to enhance cognitive function and mitigate memory deficits in rats following intracerebroventricular injection of OA. This beneficial effect may be attributed to the modulation of ChAT protein expression, tau hyperphosphorylation, NOS activity, and inflammatory cytokine levels by SSFs.

Flavonoids From Stems and Leaves of Scutellaria Baicalensis Georgi Improve Composited Aß-Induced Alzheimer's Disease Model Rats' Memory and Neuroplasticity Disorders.

AIM: The study aims to investigate the effects and mechanism of flavonoids from stems and leaves of Scutellaria baicalensis Georgi (SSF) on the disorders in learning and memory and neuroplasticity induced by beta amyloid 25-35 (Aß25-35) combined with aluminum trichloride (AlCl3) and human recombinant transfer factor-ß1 (RHTGF-ß1) (composited Aß) in rats. METHODS: A rat Alzheimer's disease (AD) model was established by intracerebroventricular injection of Aß25-35 combined with AlCl3 and RHTGF-ß1. The successful AD model of rats was screened with a Morris water maze. The successful model rats were randomly divided into a model group and three doses of SSF treated group. The Morris water maze was used to detect the rats' learning and memory abilities. The real-time fluorescence quantitative (qPCR) was applied to assay the mRNA expressions of CaM, CamkIV and Ferritin, as well as the neuroplasticity factors of HuB, HuC and HuD. The Western blotting was used to measure the protein expressions of CaM, CamkIV, HuB/D, HuC+HuD and Ferritin in the CaM-CamkIV-CREB signal pathway. RESULTS: Compared with the sham group, the abilities of learning and memory in the model group were significantly impaired (P<0.01), and the mRNA or protein expressions of CaM, CamkIV, HuB, HuC, HuD, HuB/D, HuC+HuD and Ferritin in CaM-CamkIV-CREB signal pathway were abnormally changed in model group. However, the three doses of SSF can differently ameliorate the impaired learning and memory and regulate the abnormal expressions of mRNA or protein in rats' CaM, CamkIV, HuB, HuC, HuD, HuB/D, HuC+HuD and Ferritin induced by composited Aß. CONCLUSION: The improvement of SSF on the learning and memory disorder induced by composited Aß is primarily derived from the positive regulation in the CaM-CamkIV-CREB signal pathway and activation in neuroplasticity.

The Molecular Mechanism of Scutellaria baicalensis Georgi Stems and Leaves Flavonoids in Promoting Neurogenesis and Improving Memory Impairment by the PI3K-AKT-CREB Signaling Pathway in Rats.

AIM: The aim of this study was to investigate the effect and molecular mechanism of Scutellaria baicalensis Georgi stems and leaves flavonoids (SSF) in promoting neurogenesis and improving memory impairment induced by the PI3K-AKT-CREB signaling pathway. METHODS: Alzheimer's disease (AD) was induced in the male Wistar rats by intracerebroventricular injection of amyloid beta peptide 25-35 (Aß25-35) in combination with aluminum trichloride (AlCl3) and recombinant human transforming growth factor-ß1(RHTGF-ß1) (composited Aß). The Morris water maze was used to screen the successful establishment of the memory impairment model of rats. The screened successful model rats were randomly divided into a model group and three groups of three different doses of the drug (SSF). Rats in the drug group were treated with 35, 70, and 140 mg/kg of SSF for 43 days. The Eight-arm maze was used to measure the spatial learning and memory abilities of the rat, including working memory errors (WME) and reference memory errors (RME). Immunohistochemistry was used to detect the expression of BrdU, an indicator of neuronal proliferation, in the hippocampal gyrus of rats. The mRNA and protein expressions of TRKB, PI3K, AKT, P-AKT, and IGF2 in the PI3K-AKT-CREB signaling pathway in the hippocampus and cerebral cortex of the rats were determined by quantitative real-time PCR (qPCR) and Western blotting methods. RESULTS: Compared to the sham group, the spatial memory ability of rats with composited Aß was decreased, the number of WME and RME (P < 0.01) was increased, the expression of BrdU protein (P < 0.01) in the hippocampal gyrus was reduced, the mRNA and protein expression levels of TRKB, AKT, and IGF2 (P < 0.01, P < 0.05) in the hippocampus and cerebral cortex were lowered, and the mRNA expression level of PI3K (P < 0.01) in the cerebral cortex and the protein expression level of PI3K (P < 0.01) in the hippocampus were augmented. However, compared to the model group, the three-doses of SSF improved memory disorder induced by composited Aß, reduced the number of WME and RME, increased the expression of BrdU protein in the hippocampal gyrus, and differently regulated the mRNA and protein expressions in composited Aß rats. CONCLUSION: SSF improved memory impairment and neurogenesis disorder induced by composited Aß in rats by activating the PI3K-AKT-CREB signaling pathway and up-regulating the mRNA and protein expressions of TRKB, PI3K, AKT, CREB, and IGF2.

Flavonoids from Stem and Leaf of Scutellaria Baicalensis Georgi Inhibit the Phosphorylation on Multi-sites of Tau Protein Induced by Okadaic Acid and the Regulative Mechanism of Protein Kinases in Rats.

AIM: The present study aims to investigate the effect of flavonoids from stem and leaf of Scutellaria Baicalensis Georgi (SSF) on multi-sites phosphorylation of tau protein in the cerebral cortex and hippocampus of rats induced by okadaic acid (OA) and the regulative mechanism of the protein kinases. METHODS: The model of AD-like memory impairment and neuronal injuries was established in male SD rats who were microinjected with OA (200 ng/kg) to establish a memory impairment model and screened for successful model rats by Morris water maze on day 21 after surgery. The successful model rats were continuously administered with intragastric infusion (ig) SSF 25, 50 and 100 mg/kg or Ginkgo biloba leaves flavonoids (GLF) 200 mg/kg for 36 d. The relative protein expressed levels of phosphorylated tau protein at sites of Ser199, Ser202, Ser214, Ser404 and Thr231, protein kinases (CDK5, PKA, pTyr216-GSK3ß and pSer9-GSK3ß) were detected by Western blotting. RESULTS: The relative protein expressed levels of p-tau(Ser199), p-tau(Ser202), p-tau(Ser214), p-- tau(Ser404), p-tau(Thr231) and pTyr216-GSK3ß were significantly increased in both cerebral cortex and hippocampus regions of the model rats subjected to intracerebroventricular injection of OA (P<0.01), while the protein expressed levels of CDK5, PKA and pSer9-GSK3ß (P<0.01) were reduced. SSF can dramatically reverse these increments in phosphorylated tau protein levels (P<0.01) and differently regulate the protein expressed levels of CDK5, PKA and GSK3ß (P<0.01) in rats' cerebral cortex and hippocampus induced by OA. GLF also exhibit a similar effect to SSF. CONCLUSION: The results demonstrated that SSF could inhibit the hyperphosphorylation of tau in rats' cerebral cortex and hippocampus induced by microinjection of OA, which may be related to the activities of protein kinase CDK5, PKA and GSK3ß.

Flavonoids from Scutellaria attenuate okadaic acid-induced neuronal damage in rats.

PRIMARY OBJECTIVE: To study the effect of flavonoids isolated from aerial parts of Scutellaria baicalensis Georgi (SSF) on cerebral damage induced by okadaic acid (OA) in rats. METHODS AND PROCEDURES: OA was microinjected into the right lateral ventricle of male rats at a dose of 200 ng kg(-1) twice with a 3-day interval between injections to establish a model of Alzheimer's-disease-like cerebral damage. Neuronal morphology was observed with thionin staining and the expressions of glial fibrillary acidic protein (GFAP) and ß-amyloid peptide 1-40 (Aß1-40) were monitored via immunohistochemistry. The level of malondialdehyde (MDA) and the activities of glutathione peroxidase (GSH-Px) and lactate dehydrogenase (LDH) were measured using spectrophotometry. MAIN OUTCOMES AND RESULTS: The results showed that OA-treated rats exhibited marked neuronal damage accompanied by increased levels of Aß1-40 peptide and MDA accumulation, decreased GFAP protein expression and reduced GSH-Px and LDH activity in the brain. SSF at three doses (25, 50 and 100 mg kg(-1)) dramatically reversed the OA-induced changes in the brains of rats. CONCLUSION: SSF-mediated amelioration of OA-induced neuronal damage in rats provides a rationale for assessing SSF as a means of to reducing tau hyperphosphorylation and Aß expression in the treatment of Alzheimer's disease.

The correlation between neurosteroids and neurotransmitters with liver yang rising and liver qi stagnation types of premenstrual syndrome.

BACKGROUND: To investigate neural-reproductive hormonal basis of liver yang rising (LYR), liver qi stagnation (LQS) premenstrual syndrome (PMS), and to develop standardized diagnostic criteria for PMS. METHODS: HPLC, HPLC-MC, ELISA and radioimmunoassay were used to compare levels of serum hormones, plasma neurotransmitters and neurosteroids between LYR PMS patients, LQS PMS patients and healthy controls (30 subjects in each group). RESULTS: Of the measures, all three groups exhibited no significant differences during the follicular phase. In contrast, during the luteal phase, LYR PMS testosterone levels tended to be higher than controls, while dopamine and 5-HT of the LYR PMS group were significantly higher. Conversely, γ-aminobutyric acid in the LYR PMS group was significantly lower than controls (p < 0.05). On the other hand, epinephrine and norepinephrine levels in both PMS groups were significantly higher than controls (p < 0.05), while pregnenolone and allopregnanolone of LYR and LQS groups were significantly lower than controls, with dehydroepiandrosterone (DHEA) being significantly higher than controls (p < 0.05). The ratios of DHEA/allopregnanolone and DHEA/pregnenolone of both PMS groups were significantly higher than the control group, with the LYR PMS group ratios being significantly higher than in the LQS PMS group (p < 0.05). CONCLUSION: The decrease in pregnenolone and allopregnenolone, increase in DHEA, DHEA/allopregnanolone and DHEA/pregnenolone during the luteal phase may be one of the biological bases for anger in LYR PMS patients and depression in LQS PMS patients.

Scutellaria flavonoid supplementation reverses ageing-related cognitive impairment and neuronal changes in aged rats.

PRIMARY OBJECTIVE: To study the effects of flavonoid, isolated from aerial parts of Scutellaria baicalensis Georgi (SSF), on memory impairment, neuronal damage, free radicals and energy metabolite disorders in aged rats. METHODS AND PROCEDURES: Approximately 25-month-old rats were used to establish the ageing model. The cognition of the rats was determined using the Morris water maze, neuronal morphology was observed by light/electron microscope, malondialdehyde (MDA) levels and the activity of superoxide dismutase (SOD), lactate dehydrogenase (LDH) and Na(+)-K(+)-ATPase were measured by spectrophotometry. MAIN OUTCOMES AND RESULTS: In the Morris water maze task, the aged rats always took longer latency to find the hidden platform and spent less time swimming in the target quadrant than those of young control rats. The light/electron microscopic observations found significant neuropathological changes in the aged rats' brain. In addition, the production of MDA and the activity of SOD, LDH and Na(+)-K(+)-ATPase in the hippocampus and cerebral cortex of the aged rats showed critical abnormal changes. However, pre-treatment of the aged rats with SSF (35-140 mg kg(-1)) for 16-21 days dramatically improved cognitive dysfunction, neuropathological changes and biochemical abnormalities. CONCLUSION: These results indicate that the beneficial effects of SSF on memory impairment and neuronal damage in aged rats may be important for the treatment of senile dementia and for delaying the ageing processes.

Effect of Scutellaria flavonoids on KCN-induced damages in rat pheochromocytoma PC12 cells.

BACKGROUND & OBJECTIVE: Cerebral hypoxia is known to be involved in many neurodegenerative diseases such as Alzheimer's and cerebrovascular dementia. The present study was designed to investigate the effects of flavonoids from aerial part of Scutellaria baicalensis Georgi (SSF) on potassium cyanide (KCN) -induced hypoxic cytotoxicity in rat pheochromocytoma cell line PC12, and to understand the probable mechanism. METHODS: The rat pheochromocytoma cell line PC12 was subjected to hypoxia by 200 microM KCN for 30 min. The cytotoxicity of KCN was assessed by cell viability assay, morphological observation, lactate dehydrogenase (LDH) release, malondialdehyde (MDA) production, and the activities of superoxide dismutase (SOD) and Na+-K+-ATPase measurements. The effects of SSF on the changes induced by KCN in PC12 cells were detected. RESULTS: Treatment of PC12 cells with 200 micriM KCN for 30 min increased cell death when compared with control, as assayed by MTT reduction, morphological observation and lactate dehydrogenase release measurement. These cell lesions were accompanied by disorders in SOD and Na+-K+-ATPase activities as well as MDA production. In contrast, the PC12 cells pre-treated with SSF for 24 h prior to 200 microM KCN exposure have shown protection against hypoxic toxicity. The KCN - induced decreased cell viability and activities of SOD and Na+-K+-ATPase, as well as increased MDA production were reversed by SSF pre-treatment. INTERPRETATION & CONCLUSION: SSF exerted neuroprotections against KCN - induced hypoxic cytotoxicity in PC12 cells and the probable mechanisms involved free radicals and energy metabolism. Our findings may have implications in future in the treatment of neurodegenerative diseases.

Effects of amelioration of total flavonoids from stems and leaves of Scutellaria baicalensis Georgi on cognitive deficits, neuronal damage and free radicals disorder induced by cerebral ischemia in rats.

Previous studies reported that the total flavonoids from the stems and leaves of Scutellaria baicalensis Georgi (TFSS) could enhance and improve learning and memory abilities in experimental animals, and reduce the neuronal pathologic alterations induced by some reagents in mice. The present study examined whether TFSS can improve memory dysfunction, neuronal damage, and abnormal free radicals induced by permanent cerebral ischemia in rats. The permanent cerebral ischemic model in rats was produced by bilateral ligation of the common carotid arteries. The influence of permanent cerebral ischemia on learning and memory was determined in the Morris water maze. The neuronal damage in the hippocampus and cerebral cortex was assessed by the neuronal morphologic observations. The contents of malondialdehyde (MDA) and nitric oxide (NO), and the activities of superoxide dismutase (SOD) and catalase (CAT) in the hippocampus and cerebral cortex were measured using thiobarbituric acid, nitrate reductase, xanthine-xanthine oxidase, and ammonium molybdate spectrophotometric methods, respectively. In learning and memory performance tests, cerebral ischemic rats always required a longer latency time to find the hidden platform and spent a shorter time in the target quadrant in the Morris water maze. TFSS 17.5-70 mg.kg(-1) daily orally administered to ischemic rats for 20 d, from day 16-35 after operation differently reduced the prolonged latency and increased swimming time spent in the target quadrant. In neuronal morphologic observations, daily oral TFSS 17.5-70 mg.kg(-1) for 21 d, from day 16-36 after operation markedly inhibited the ischemia-induced neuronal damage. In addition, the increased contents of MDA and NO, and SOD activity, and the decreased activity of CAT in the hippocampus and cerebral cortex induced by cerebral ischemia were differently reversed. The reference drug piracetam (140 mg.kg(-1) per day for 20-21 d) similarly improved impaired memory and neuronal damage but had no significant effects on free radicals in ligated rats. TFSS can improve memory deficits and neuronal damage in rats after permanent cerebral ischemia, which may be beneficial in the treatment of cerebrovascular dementia.

Prevention of oxidative injury by flavonoids from stems and leaves of Scutellaria baicalensis Georgi in PC12 cells.

Reactive oxygen species (ROS) are important mediators in a number of neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD). The neuroprotective effects of flavonoids from the stems and leaves of Scutellaria baicalensis Georgi (SSF) against hydrogen peroxide (H2O2)-induced rat pheochromocytoma line PC12 injury were evaluated by cell lesion, free radicals and ATPase disorders. Following a 30 min exposure of the cells to H2O2 (100 microm), a marked decrease in cell survival and activity of superoxide dismutase (SOD) and Na+-K+-ATPase as well as an increase of malondialdehyde (MDA) production and lactate dehydrogenase (LDH) release were observed. Pretreatment of the cells with SSF (18-76 microg/mL) prior to H2O2 exposure notably elevated the cell survival and activity of SOD and Na+-K+-ATPase, and lowered the MDA level and LDH release. Neuroprotection by SSF was also observed in animal models. The present results indicated that SSF exerts neuroprotective effects against H2O2 toxicity, which might be of importance and might contribute to its clinical efficacy for the treatment of neurodegenerative disease.