Exploring the role and mechanism of hyperoside against cardiomyocyte injury in mice with myocardial infarction based on JAK2/STAT3 signaling pathway.

BACKGROUND: Myocardial infarction (MI) is one of the most deadly diseases in the world. Hyperoside (Hyp) has been shown to have a protective effect on cardiovascular function through various signaling pathways, but whether it can protect myocardial infarction by regulating JAK2/STAT3 signaling pathway is unknown. AIM OF THE STUDY: To investigate whether Hyp could protect the heart against myocardial infarction injury in mice by modulating JAK2/STAT3 signaling pathway and its potential mechanism. METHODS: In vivo experiments, the myocardial infarction model was established by ligating the left anterior descending coronary artery (LAD) of male C57BL/6 mice permanently. The mice were divided into seven groups: sham group, MI group, MI+Hyp (9 mg/kg), MI+Hyp (18 mg/kg) group, MI+Hyp (36 mg/kg) group, MI+Captopril group (15 mg/kg) group and MI+Hyp (36 mg/kg)+AG490 (7.5 mg/kg) group. Each group of animals were given different concentrations of hyperoside, positive control drug or inhibitor of JAK2/STAT3 singaling. After 14 days of administration, the electrocardiogram (ECG), echocardiography and serum myocardial injury markers were examined; Slices of mouse myocardial tissue were assessed for histopathological changes by HE, Masson and Sirius Red staining. TTC and TUNEL staining were used to evaluate the myocardial infarction area and cardiomyocytes apoptosis respectively. The expression of JAK2/STAT3 signaling pathway, apoptosis and autophagy-related proteins were detected by western blot. In vitro experiments, rat H9c2 cardiomyocytes were deprived of oxygen and glucose (OGD) to stimulate myocardial ischemia. The experiment was divided into seven groups: Control group, OGD group, OGD+Hyp (20 µM) group, OGD+Hyp (40 µM) group, OGD+Hyp (80 µM), OGD+Captopril (10 µM) group and OGD+Hyp (80 µM)+AG490 (100 µM) group. Myocardial cell damage and redox index were measured 12 h after OGD treatment. ROS content in cardiomyocytes was detected by immunofluorescence. Cardiomyocytes apoptosis was detected by flow cytometry. The expressions of JAK2/STAT3 signaling pathway-related proteins, apoptosis and autophagy related proteins were detected by western blot. RESULTS: In vivo, hyperoside could ameolirate ECG abnormality, increase cardiac function, reduce myocardial infarction size and significantly reduce myocardial fibrosis level and oxidation level. The experimental results in vitro showed that Hyp could reduce the ROS content in cardiomyocytes, decrease the level of oxidative stress and counteract the apoptosis induced by OGD injury . Both in vivo and in vitro experiments showed that hyperoside could increase phosphorylated JAK2 and STAT3, indicating that hyperoside could play a cardioprotective role by activating JAK2/STAT3 signaling pathway. It was also shown that hyperoside could increase the autophagy level of cardiomyocytes in vivo and in vitro. However the cardiomyocyte-protective effect of Hyp was abolished in combination with JAK2/ STAT3 signaling pathway inhibitor AG490. These results indicated that the protective effect of Hyp on cardiomyocyte injury was at least partially achieved through the activation of the JAK2/STAT3 signaling pathway. CONCLUSION: Hyp can significantly improve cardiac function, ameliorate myocardial hypertrophy and myocardial remodeling in MI mice. The mechanism may be related to improving mitochondrial autophagy of cardiomyocytes to maintain the advantage of autophagy, and blocking apoptosis pathway through phagocytosis, thus suppressing apoptosis level of cardiomyocytes. These effects of Hyp are achieved, at least in part, by activating the JAK2/STAT3 signaling pathway.

An integrated analytical strategy to decipher the metabolic profile of alkaloids in Compound Kushen injection based on UHPLC-ESI-QTOF/MSE.

Compound Kushen injection (CKI) is a kind of sterilised water-soluble traditional Chinese medicine preparation that has been used for the clinical treatment of a variety of cancers (hepatocellular carcinoma, lung cancer, etc.) for 19 years. However, to date, the metabolism-related study on CKI in vivo has not been conducted.An integrated analytical strategy was established to investigate the metabolic profile of alkaloids of CKI in rat plasma, urine, and faeces based on ultra-high performance liquid chromatography-electrospray quadrupole time-of-flight mass spectrometry in MSE mode (UHPLC-ESI-QTOF/MSE).Nineteen prototype alkaloids (including 12 matrine-type alkaloids, 2 cytisine-type alkaloids, 3 lupinine-type alkaloids, and 2 aloperine-type alkaloids) of CKI were identified in vivo. Furthermore, 71 metabolites of alkaloids (including 11 of lupanine-related metabolites, 14 of sophoridine-related metabolites, 14 of lamprolobine-related metabolites, and 32 of baptifoline-related metabolites) were tentatively characterised. Metabolic pathways involved in the metabolism of phase I (include oxidation, reduction, hydrolysis, and desaturation), phase II (mainly include glucuronidation, acetylcysteine or cysteine conjugation, methylation, acetylation, and sulphation), and associated combination reactions.The integrated analytical strategy was successfully used to characterise the prototype alkaloids and their metabolites of CKI in vivo, and the results laying a foundation for further study its pharmacodynamic substances.

Exploration of the main active components and pharmacological mechanism of Yerba Mate based on network pharmacology.

INTRODUCTION: Yerba mate is widely consumed in South American countries and is gaining popularity around the world. Long-term consumption of yerba mate has been proven to have health-care functions and therapeutic effects on many diseases; however, its underlying mechanism has not been clearly elucidated. In this research, we explored the pharmacological mechanism of yerba mate through a network pharmacological approach. MATERIAL AND METHODS: The bioactive components of yerba mate were screened from published literature and the Traditional Chinese Medicine System Pharmacology Database (TCMSP), and the targets and related diseases were retrieved by TCMSP. Furthermore, the component-target-disease network an protein-protein interaction (PPI) network were constructed, and combined with gene ontology (GO) functional analysis and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment analysis to explore the pharmacological mechanism of yerba mate. RESULTS: As a result, 16 bioactive components of yerba mate were identified, which acted on 229 targets in total. Yerba mate can be used to treat 305 diseases, such as breast cancer, asthma, Alzheimer's disease, osteoarthritis, diabetes mellitus, atherosclerosis, and obesity. Protein kinase B (AKT1), signal transducer and activator of transcription 3 (STAT3), mitogen-activated protein kinase 1 (MAPK1), transcription factor AP-1 (JUN), cellular tumour antigen (p53) TP53, tumour necrosis factor (TNF), transcription factor p65 (RELA), interleukin-6 (IL6), amyloid-beta precursor protein (APP), and vascular endothelial growth factor A (VEGFA) were identified as the key targets of yerba mate playing pharmacological roles. The signalling pathways identified by KEGG pathway enrichment analysis that were most closely related to the effects of yerba mate included pathways in cancer, fluid shear stress and atherosclerosis, and human cytomegalovirus infection. CONCLUSION: the results of our study preliminarily verify the basic pharmacological action and possible mechanism of yerba mate and provide a reference for the further development of its medicinal value.

Unique BiFeO3/g-C3N4 mushroom heterojunction with photocatalytic antibacterial and wound therapeutic activity.

Bacterial infections have become a major problem threatening public health, and it is of great significance to treat wound infections in biological systems caused by bacteria. However, traditionally used bacteriostatic agents usually cause additional pollution. Herein a mushroom-shaped clean and Green BiFeO3/g-C3N4 composite is employed for the first time for photocatalytic antibacterial activity and for the further promotion of wound healing. The ratio between BiFeO3 and g-C3N4 was delicately regulated to control the generated amount of ˙OH and ˙O2- by catalyzing the decomposition of hydrogen peroxide (H2O2) under illumination. Results show that 10%BFO/CN demonstrates the best performance for ˙OH and ˙O2- production, resulting in the highest antibacterial ability against E. coli and S. aureus. In addition, the catalytic mechanism of BiFeO3/g-C3N4 towards antibacterial activity is disclosed by a combination of ESR monitoring and analysis of the Mott-Schottky diagram. Furthermore, in vivo experiments prove that 10%BFO/CN can effectively promote anti-infection and wound healing in nude mice. This work sheds deep scientific insight on the synergistic effect of photocatalysis and photo-Fenton degradation as well as their application in antibacterial and wound therapeutic activity.

Cascade catalytic nanoplatform based on ions interference strategy for calcium overload therapy and ferroptosis.

Intracellular ions played prominent part in cell function and behavior. Disrupting intracellular ions homeostasis might switch ions signal from "regulating" to "destroying". Inspired by this, we introduced the ions interference strategy for tumor therapy. Herein, curcumin (CUR) and transferrin (Tf) co-loaded calcium peroxide nanoparticles (CaO2 NPs) were formulated. With tumor targeting ability, CaO2/Tf/CUR pinpointed tumor cells and then instantaneously decomposed in acidic lysosomes, concurrently accompanying with the release of Ca2+ and CUR, as well as the production of H2O2. Then H2O2 not only damaged structure of Tf to release Fe3+, but also was converted to hydroxyl radicals via ferric ions mediated Fenton reaction for ferroptosis. In addition, the released Ca2+ and CUR induced Ca2+ overload via exogenous and endogenous calcium ions accumulation, respectively, further activating mitochondria apoptosis signaling pathway for cell injury. Therefore, based on calcium and ferric ions interference strategy, the cascade catalytic CaO2/Tf/CUR offered synergistic combination of ferroptosis, Ca2+ overload therapy and chemotherapy, which held a great promise in cancer treatment.

Biochanin A protects against angiotensin II-induced damage of dopaminergic neurons in rats associated with the increased endophilin A2 expression.

The brain renin-angiotensin system plays a vital role in the modulation of the neuroinflammatory responses and the progression of dopaminergic (DA) degeneration. Angiotensin II (Ang II) induces microglia activation via angiotensin II type 1 receptor (AT1R), which in turn affects the function of DA neurons. Endophilin A2 (EPA2) is involved in fast endophilin-mediated endocytosis and quickly endocytoses several G-protein-coupled receptor (GPCR), while AT1R belongs to GPCR family. Therefore, we speculated that EPA2 may modulate microglia activation via endocytosing AT1R. Biochanin A is an O-methylated isoflavone, classified as a kind of phytoestrogen due to its chemical structure that is similar to mammalian estrogens. In this study, we investigated the protective effects of biochanin A on Ang II-induced DA neurons damage in vivo, and molecular mechanisms. The results showed that biochanin A treatment for 7 days attenuated the behavioral dysfunction, inhibited the microglial activation, and prevented DA neuron damage in Ang II-induced rats. Furthermore, biochanin A increased EPA2 expression and decreased the expression of AT1R, gp91phox, p22 phox, NLRP3, ASC, Caspase-1, IL-1ß, IL-6, IL-18, and TNF-α. In summary, these results suggest that biochanin A exerts protective effects in Ang II-induced model rats, and the mechanisms may involve inhibition of inflammatory responses, an increase in EPA2 expression and a decrease in AT1R expression.

Ginsenoside Rg1 protects against neuronal degeneration induced by chronic dexamethasone treatment by inhibiting NLRP-1 inflammasomes in mice.

Glucocorticoids (GCs) are known to alter neuronal plasticity, impair learning and memory and play important roles in the generation and progression of Alzheimer's disease. There are no effective drug options for preventing neuronal injury induced by chronic GC exposure. Ginsenoside Rg1 (Rg1) is a steroidal saponin found in ginseng. The present study investigated the neuroprotective effect of Rg1 on neuroinflammation damage induced by chronic dexamethasone (5 mg/kg for 28 days) exposure in male mice. Our results showed that Rg1 (2 and 4 mg/kg) treatment increased spontaneous motor activity and exploratory behavior in an open field test, and increased the number of entries into the new object zone in a novel object recognition test. Moreover, Rg1 (2 and 4 mg/kg) treatment significantly alleviated neuronal degeneration and increased MAP2 expression in the frontal cortex and hippocampus. Additionally, inhibition of NLRP­1 inflammasomes was also involved in the mechanisms underlying the effect of Rg1 on GC­induced neuronal injury. We found that Rg1 (2 and 4 mg/kg) treatment increased the expression of glucocorticosteroid receptor and decreased the expression of NLRP­1, ASC, caspase­1, caspase­5, IL­1ß and IL­18 in the hippocampus in male mice. The present study indicates that Rg1 may have protective effects on neuroinflammation and neuronal injury induced by chronic GC exposure.

Biochanin A Protects Against Lipopolysaccharide-Induced Damage of Dopaminergic Neurons Both In Vivo and In Vitro via Inhibition of Microglial Activation.

Neuroinflammation has been reported to be involved in the pathogenesis of Parkinson's disease (PD). Inhibition of microglia-mediated neuroinflammation might be a potential strategy for PD treatment. Biochanin A, is an O-methylated isoflavone, classified as a kind of phytoestrogens due to its chemical structure that is similar to mammalian estrogens. It has been found to possess antifibrotic, antiapoptotic, and antioxidant effects. In the present study, we investigated the neuroprotective effects of biochanin A on lipopolysaccharide (LPS)-induced dopaminergic neurons damage both in vivo and in vitro and the related molecular mechanisms. The results showed that biochanin A treatment for 21 days significantly attenuated the behavioral dysfunction of PD rats, prevented dopaminergic neurons damage, and inhibited activation of microglia in the LPS-induced PD rats. Furthermore, biochanin A decreased the levels of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in the serum, and inhibited the phosphorylation of ERK, JNK, p38 in the substantia nigra of PD rats. In vitro test, biochanin A also inhibited primary microglial activation and protected dopaminergic neurons, decreased the content of nitric oxide, IL-1ß, and TNF-α in supernatants, and inhibited the reactive oxygen species production. Taken together, these results suggest that biochanin A exerts protective effects on LPS-induced PD rats, and the mechanisms may be associated with the inhibition of inflammatory response and the MAPK signaling pathway.

Protective effect of polysaccharides from Opuntia dillenii Haw. fruits on streptozotocin-induced diabetic rats.

In this study, a novel water-soluble polysaccharide fraction with molecular weight of 6479.1kDa was isolated from the fruits of Opuntia dillenii Haw., which consisted of rhamnose, xylose, mannose and glucose in the molar ratio of 14.99:1.14:1.00:6.47. The protective effect of O. dillenii Haw. fruits polysaccharide (ODFP) against oxidative damage in streptozotocin (STZ)-induced diabetic rats was investigated. The results showed that oral administration of ODFP significantly decreased food intake, water intake, urine production, organ weights and blood glucose level, and increased body weight in STZ-induced diabetic rats. ODFP also significantly increased the activities of SOD, GPx and CAT, and decreased malondialdehyde level in serum, liver, kidney, and pancreas in STZ-induced diabetic rats. Moreover, histopathological examination showed that ODFP could markedly improve the structure integrity of pancreatic islet tissue in STZ-induced diabetic rats. These results suggest that ODFP have hypoglycemic and antioxidant properties and can protect rats from STZ-induced oxidative damage.

Investigation of in vitro and in vivo antioxidant activities of flavonoids rich extract from the berries of Rhodomyrtus tomentosa(Ait.) Hassk.

This study investigated the in vitro and in vivo antioxidant activities of the flavonoids rich extract from Rhodomyrtus tomentosa Hassk (R. tomentosa) berries. The in vitro antioxidant assay demonstrated that the flavonoids rich extract (62.09% rutin equivalent) extracted by ethanol and purified by AB-8 macroporous resin was strong in reducing power, superoxide radical, hydroxyl radical and DPPH radical scavenging activity, as well as inhibiting lipid peroxidation. In the in vivo assays, the flavonoids rich extract significantly enhanced the activities of antioxidant enzymes in serums of mice after they were administered with the extract. The results suggested that the flavonoids rich extract from R. tomentosa fruits possesses potent antioxidant properties. In addition, the chemical compositions of flavonoids rich extract were identified by UPLC-TOF-MS/MS. Six flavonoids were tentatively identified as myricetin, quercetin, dihydromyricetin, kaempferol, quercetin 7,4'-diglucoside and vitexin. Therefore, R. tomentosa berries could be used as a new source of antioxidant ingredient.

Anti­fibrotic effects of Acremoniumterricola milleretal mycelium on immunological hepatic fibrosis in rats.

Acremoniumterricola milleretal mycelium (AMM) exerts numerous protective effects on organs, and has been used in Chinese herb prescriptions to treat refractory diseases. The aim of this study was to investigate the effects of AMM on immunological hepatic fibrosis induced by porcine serum (PS) in rats. Male Sprague Dawley rats were administered 0.5 ml sterile PS by intraperitoneal injections twice a week for 18 weeks. AMM (175, 350 or 700 mg/kg) and colchicine (0.1 mg/kg) were administered intragastrically each day until the rats were sacrificed. PS administration resulted in marked hepatic fibrosis, as assessed by increased oxidative stress and hepatic collagen content, as well as α­smooth muscle actin (α­SMA) expression. AMM significantly reduced liver damage and fibrosis. In addition, AMM decreased the elevation in hydroxyproline, hyaluronic acid, laminin and procollagen type III; increased the activity of superoxide dismutase and glutathione peroxidase; decreased α­SMA expression; and eliminated hepatic collagen deposits. Furthermore, AMM inhibited Smad2/3 phosphorylation and Smad7 expression. These results indicate that AMM is able to reduce oxidative stress, inhibit collagen synthesis and block the transforming growth factor­ß/Smad signaling pathway in a dose­dependent manner.

Effects of cichoric acid extract from Echinacea purpurea on collagen-induced arthritis in rats.

Cichoric acid extract (CAE) from Echinacea purpurea L. was used to investigate the anti-arthritic effect by using collagen-induced arthritis (CIA) rat model. The hind paw swelling volume and the body weight were measured and recorded. All the drug solutions were administered orally to rats for a total of 28 days. On day 28, the rats were anaesthetized and decapitated. The thymus and spleen were weighed for the determination of the organ index. The concentration of tumor necrosis factor alpha (TNFα), interleukin-1 beta (IL-1ß) and prostaglandin E2 (PGE-2) in the serum was measured using commercially available ELISA kits. Total and phosphor-NF-κB and Cox-2 protein expression in synovial tissues were determined by histological slides quantification and western blot analysis. Our data showed that administration of all doses of CAE (8, 16, and 32 mg/kg) significantly decreased the paw swelling, restored body weight gain and decreased the organ index of the thymus and spleen compared with that of the CIA group. CAE (8, 16, and 32 mg/kg) treatment significantly reduced the levels of TNFα, IL-1ß and PGE-2 in serum compared with the CIA group. Histopathological analysis demonstrated that CAE has obvious anti-arthritic activity. In addition, CAE (32 mg/kg) significantly decreased the levels of nuclear factor-κB (NF-κB), TNFα and cyclooxygenase 2 (Cox-2) in synovium tissues of the ankle joint compared with the CIA group. Furthermore, CAE administration significantly decreased the protein expression of phosphor-NF-κB and Cox-2 in synovium tissues of the knee joint compared with the CIA group. The results suggest that the anti-inflammatory activity of CAE may account for its anti-arthritic effect, and CAE could be a potential therapeutic drug for the treatment of rheumatoid arthritis (RA).

Protective effects of ginsenoside Rg1 on chronic restraint stress induced learning and memory impairments in male mice.

Alzheimer's disease (AD) is one of the major neurological diseases of the elderly. Chronic stress, which can induce atrophy and functional impairments in several key brain areas such as the frontal cortex and hippocampus, plays an important role in the generation and progression of AD. Currently, there are no effective drug treatment options for preventing chronic stress induced learning and memory impairments and neuronal damage. Ginsenoside Rg1 (Rg1) is a steroidal saponin abundantly contained in ginseng. This study explored the neuroprotective effects of Rg1 on chronic restraint stress (CRS) induced learning and memory impairments in a mouse model. Our results showed that Rg1 (5mg/kg) significantly protected against learning and memory impairments induced by CRS in a Morris water maze. Besides, Rg1 (2, 5mg/kg) was able to decrease ROS generation and attenuate the neuronal oxidative damage in the frontal cortex and hippocampus CA1 in mice. Additionally, the inhibition of NOX2, p47phox and RAC1 expression is also involved in the action mechanisms of Rg1 in this experimental model. This study provided an experimental basis for the clinical application of Rg1 in chronic stress induced neuronal oxidative damage.

Effects and mechanisms of Acremoniumterricola milleretal mycelium on liver fibrosis induced by carbon tetrachloride in rats.

Acremoniumterricola milleretal mycelium (AMM) is one of the most precious traditional Chinese medicines. It has numerous protective effects on organs, and has been used in Chinese herb prescription to treat refractory diseases. Our preliminary studies demonstrated that AMM had hepatoprotective activity in acute liver injury. We further investigated the effects of AMM on liver fibrosis in rats induced by carbon tetrachloride (CCl(4)) and explore its possible mechanisms. The animal model was established by injection with 50% CCl(4) subcutaneously in male Sprague-Dawley rats twice a week for eight weeks. Meanwhile, AMM (175, 350 and 700 mg/kg) was administered intragastrically per day until sacrifice. We found that treatment with AMM (175, 350 and 700 mg/kg) decreased CCl(4)-induced elevation of serum transaminase activities, hyaluronic acid, laminin and procollagen type III levels, and contents of hydroxyproline in liver tissues. It also restored the decreased SOD and GSH-Px activities and inhibited the formation of lipid peroxidative products during CCl(4) treatment. Moreover, AMM (350 and 700 mg/kg) decreased the elevation of TGF-ß1 by 19.6% and 34.3%, respectively. In the pathological study, liver injury and the formation of liver fibrosis in rates treated by AMM were improved significantly. Immunoblot analysis showed that AMM (175, 350 and 700 mg/kg) inhibited Smad 2/3 phosphorylation, and elevated inhibitor Smad 7 expression. These results suggested that AMM could protect liver damage and inhibit the progression of hepatic fibrosis induced by CCl(4), and its mechanisms might be associated with its ability to scavenge free radicals, decrease the level of TGF-ß1 and block TGF-ß/Smad signaling pathway.

Protective effect of extract of Astragalus on learning and memory impairments and neurons' apoptosis induced by glucocorticoids in 12-month-old male mice.

Alzheimer's disease (AD) is a chronic neurodegenerative disorder marked by a progressive loss of memory and cognitive function. Stress-level glucocorticoids are correlated with dementia progression in patients with AD. In this study, 12-month male mice were chronically treated with stress-level dexamethasone (DEX, 5 mg/kg) and extract of Astragalus (EA, 10, 20, and 40 mg/kg) or Ginsenoside Rg1 (Rg1, 6.5 mg/kg) for 21 days. We investigated the protective effect of EA against DEX injury in mice and its action mechanism. Our results indicate that DEX can induce learning and memory impairments and neuronal cell apoptosis. The mRNA levels of caspase-3 are selectively increased after DEX administration. The results of immunohistochemistry demonstrate that caspase-3 and cytochrome c in hippocampus (CA1, CA3) and neocortex are significantly increased. Furthermore, DEX treatment increased the activity of caspase-9 and caspase-3. Treatment groups with EA (20 and 40 mg/kg) or Rg1 (6.5 mg/kg) significantly improve learning and memory, downregulate the mRNA level of caspase-3, decrease expression of caspase-3 and cytochrome c in hippocampus (CA1, CA3) and neocortex, and inhibit activity of caspase-9 and caspase-3. The present findings highlight a possible mechanism by which stress level of DEX accelerates learning and memory impairments and increases neuronal apoptosis and the potential neuronal protection of EA.

[Effects of ginkgolide on hemodynamics in myocardial ischemic dogs].

OBJECTIVE: To investigate the effects of Ginkgolide on hemodynamics and myocardial oxygen metabolism in acute myocardial ischemic dogs. METHODS: Acute myocardial ischemic model dogs were established by ligating left anterior descending coronary artery (LAD). Some hemodynamic parameters and cardiac oxygen consumption were observed after Ginkgolide were given to dogs through the duodenum. RESULTS: Ginkgolide could increase LVSP, + dp/dt(max), LVWI, SW, CO and CBF, decrease TPVR, CVR, MVO2 and MOUR of Acute myocardial ischemic model dogs at different time points after ligation of LAD. CONCLUSION: Ginkgolide can improve the hemodynamic conditions and oxygen metabolism of myocardial ischemic dogs.

Protective effect of astragaloside on focal cerebral ischemia/reperfusion injury in rats.

This study was to observe the neurological protective effects of astragalosides (AST) on focal cerebral ischemia-reperfusion (I/R) injury in rats and to explore its possible mechanism. Male SD rats received right middle cerebral artery occlusion for 120 min and AST (40 mg/kg) was orally administered. The rats were decapitated 1, 3, 7, and 14 days after reperfusion. The neurological deficit score, infarct volume and water content of brain were measured; the activity of superoxide dismutase (SOD), lactate dehydrogenase (LDH) and nitric oxide synthase (NOS), and the content of malondialdehyde (MDA), lactate (LD) and nitric oxide (NO) of brain tissue were detected too. The expression of inducible nitric synthase (iNOS), nerve growth factor (NGF) and tropomyosin receptor kinase A (TrkA) mRNA were measured by RT-PCR or real-time PCR. AST could significantly reduce the neurological deficit score; infract volume and water content, increase SOD and LDH activities, decrease NOS activity and MDA, LD and NO content. AST treatment could down-regulate expression of iNOS mRNA, while, NGF and TrkA mRNA were up-regulated. Our data suggest that AST have the protective effects on focal cerebral ischemia in rats at the different reperfusion time points, the mechanism may be related to the antioxidation, regulated the expressions of iNOS, NGF and TrkA mRNA.

[Protective effect of astragalosides on anoxia/reoxygenation injury of hippocampal neuron].

OBJECTIVE: To study the effect of astragalosides (AST) on the anoxia/reoxygenation (A/R) injured neuron in rat. METHODS: Primary cultured rat's hippocampal neurons were made into A/R model cells. The cell viability was detected by MTT assay and lactate dehydrogenase releasing methods; the activity of superoxide dismutase (SOD), and contents of malondialdehyde (MDA) and nitride oxide (NO) in culture supernate were detected; the apoptosis rate of hippocampal neurons after A/R was measured by flow cytometry with double-staining of Hoechst33258 and AnnexinV-PI; and intracellular calcium ion [Ca2+]i was observed with a cofocal laser-scanning microscope and determined by fluorescent probe Fluo-3/AM. RESULTS: AST enhanced the cell viability of neurons after A/R injury, increased SOD activity and decreased the MDA and NO contents in supernate, reduced the A/R-induced apoptosis and decreased the calcium overload in neurons. CONCLUSION: AST has the protective effects on A/R injured neurons, the mechanism is possibly related with its anti-oxidation and calcium overload reducing actions.

[Hypoglycemic activity and mechanism of Polygona-polysaccharide on diabetic rat model].

OBJECTIVE: To study the effects of Polygona-polysaccharose (PSP) on blood glucose level and the mechanism of protection on diabetic rats induced by streptozotocin (STZ). METHOD: The animal model of diabetes was established by injecting STZ (60 mg x kg(-1)) into its abdominal cavity. The amount of water drinking, food intake, urinary volume and body weight were measured at the fourth week of the treatment. The blood samples were drawn to determine the indexes of blood glucose (FBG) and Glycosylated serum protein (GSP) and blood serum insulin (INS). Pancreatic pathology was studied with morphological method and immunohistochemical method. The distribution of apoptotic cells and the expression of Caspase-3 were observed by TUNEL and immunohistochemistry. RESULT: The levels of FBG, GSP and the amount of water drinking, food intake, urinary volume in the PSP treated groups were obviously lower than those in the model group while INS increased. PSP decreased the rate of apoptotic cells and the level of Caspase-3. CONCLUSION: PSP can effectivly decrease blood glucose and increase INS. The mechanism may be related with inhibiting islet cell apoptosis and lowering Caspase-3.

[Protective effects of AST and ASI on memory impairment and its mechanism in senescent rats treated by GC].

OBJECTIVE: To study the protective effects and mechanisms of astragaloside (AST) and astragalus saponin I (ASI) on the memory impairment in senescent rats treated by glucocorticoid (GC). METHOD: Y maze test was performed to determine the effects of AST and ASI on memory impairment of hydrocortisone(HC)-induced senescent rats. Using Ca2+ sensitive fluorescent indicator (Furo-2), free intracellular calcium concentration ([Ca2+]i) was measured by double wavelength fluorescence sepectrophotometer in thymocytes and hippocampal neurons induced dexamethasone (DEX). And apoptosis was detected by DNA gel electrophoresis and flow cytometry. RESULT: Compared with HC control, AST and ASI can improve the memory of the senescent rats treated by HC, lower [Ca2+]i and suppress apoptosis of thymocytes and hippocampal neurons induced by DEX. CONCLUSION: AST and ASI can delay the aging in rats treated by HC, and its mechanism may includ lowering[Ca2+]i and suppressing the apoptosis of thymocytes and hippocampal neurons.