Total Saponins of Panax notoginseng Activate Akt/mTOR Pathway and Exhibit Neuroprotection in vitro and in vivo against Ischemic Damage.

OBJECTIVE: To reveal the neuroprotective effect and the underlying mechanisms of a mixture of the main components of Panax notoginseng saponins (TSPN) on cerebral ischemia-reperfusion injury and oxygen-glucose deprivation/reoxygenation (OGD/R) of cultured cortical neurons. METHODS: The neuroprotective effect of TSPN was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, flow cytometry and live/dead cell assays. The morphology of dendrites was detected by immunofluorescence. Middle cerebral artery occlusion (MCAO) was developed in rats as a model of cerebral ischemia-reperfusion. The neuroprotective effect of TSPN was evaluated by neurological scoring, tail suspension test, 2,3,5-triphenyltetrazolium chloride (TTC) and Nissl stainings. Western blot analysis, immunohistochemistry and immunofluorescence were used to measure the changes in the Akt/mammalian target of rapamycin (mTOR) signaling pathway. RESULTS: MTT showed that TSPN (50, 25 and 12.5 µ g/mL) protected cortical neurons after OGD/R treatment (P<0.01 or P<0.05). Flow cytometry and live/dead cell assays indicated that 25 µ g/mL TSPN decreased neuronal apoptosis (P<0.05), and immunofluorescence showed that 25 µ g/mL TSPN restored the dendritic morphology of damaged neurons (P<0.05). Moreover, 12.5 µ g/mL TSPN downregulated the expression of Beclin-1, Cleaved-caspase 3 and LC3B-II/LC3B-I, and upregulated the levels of phosphorylated (p)-Akt and p-mTOR (P<0.01 or P<0.05). In the MCAO model, 50 µ g/mL TSPN improved defective neurological behavior and reduced infarct volume (P<0.05). Moreover, the expression of Beclin-1 and LC3B in cerebral ischemic penumbra was downregulated after 50 µ g/mL TSPN treatment, whereas the p-mTOR level was upregulated (P<0.05 or P<0.01). CONCLUSION: TSPN promoted neuronal survival and protected dendrite integrity after OGD/R and had a potential therapeutic effect by alleviating neurological deficits and reversing neuronal loss. TSPN promoted p-mTOR and inhibited Beclin-1 to alleviate ischemic damage, which may be the mechanism that underlies the neuroprotective activity of TSPN.

Total Saponins of Panax notoginseng Activate Akt/mTOR Pathway and Exhibit Neuroprotection in vitro and in vivo against Ischemic Damage / 中国结合医学杂志

OBJECTIVE@#To reveal the neuroprotective effect and the underlying mechanisms of a mixture of the main components of Panax notoginseng saponins (TSPN) on cerebral ischemia-reperfusion injury and oxygen-glucose deprivation/reoxygenation (OGD/R) of cultured cortical neurons.@*METHODS@#The neuroprotective effect of TSPN was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, flow cytometry and live/dead cell assays. The morphology of dendrites was detected by immunofluorescence. Middle cerebral artery occlusion (MCAO) was developed in rats as a model of cerebral ischemia-reperfusion. The neuroprotective effect of TSPN was evaluated by neurological scoring, tail suspension test, 2,3,5-triphenyltetrazolium chloride (TTC) and Nissl stainings. Western blot analysis, immunohistochemistry and immunofluorescence were used to measure the changes in the Akt/mammalian target of rapamycin (mTOR) signaling pathway.@*RESULTS@#MTT showed that TSPN (50, 25 and 12.5 µ g/mL) protected cortical neurons after OGD/R treatment (P<0.01 or P<0.05). Flow cytometry and live/dead cell assays indicated that 25 µ g/mL TSPN decreased neuronal apoptosis (P<0.05), and immunofluorescence showed that 25 µ g/mL TSPN restored the dendritic morphology of damaged neurons (P<0.05). Moreover, 12.5 µ g/mL TSPN downregulated the expression of Beclin-1, Cleaved-caspase 3 and LC3B-II/LC3B-I, and upregulated the levels of phosphorylated (p)-Akt and p-mTOR (P<0.01 or P<0.05). In the MCAO model, 50 µ g/mL TSPN improved defective neurological behavior and reduced infarct volume (P<0.05). Moreover, the expression of Beclin-1 and LC3B in cerebral ischemic penumbra was downregulated after 50 µ g/mL TSPN treatment, whereas the p-mTOR level was upregulated (P<0.05 or P<0.01).@*CONCLUSION@#TSPN promoted neuronal survival and protected dendrite integrity after OGD/R and had a potential therapeutic effect by alleviating neurological deficits and reversing neuronal loss. TSPN promoted p-mTOR and inhibited Beclin-1 to alleviate ischemic damage, which may be the mechanism that underlies the neuroprotective activity of TSPN.

Preparation, optimization, and in vivo evaluation of an inhaled solution of total saponins of Panax notoginseng and its protective effect against idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive pulmonary disease that can cause fibrotic remodeling of the surrounding lung, thus leading to respiratory failure. Although IPF is the most common form of idiopathic interstitial pneumonia, the precise mechanisms underlying this condition remain unknown. In this study, we used total saponins of Panax notoginseng inhalation solution (TIS) to induce idiopathic bleomycin-induced pulmonary fibrosis in rats. The uniformity of delivery dose was investigated by analyzing the aerodynamic particle size distribution and drug stability. The potential of hydrogen potential of hydrogen (pH) of the inhalation solution was 7.0 and the solvent 0.9% NaCl solution, thus meeting physiological requirements for pulmonary drug administration. The delivery rate was 1.94 ± 0.16 mg·min-1 and the total dose was 17.40 ± 0.04 mg. TIS was composed of five key components: notoginsenoside R1, ginsenosides Rg1, ginsenosides Re, ginsenosides Rb1, and ginsenosides Rd. The mass median aerodynamic diameter (MMAD) for these five components were 3.62 ± 0.05 µm, 3.62 ± 0.06 µm, 3.65 ± 0.10 µm, 3.62 ± 0.06 µm, and 3.61 ± 0.05 µm, respectively. Fine particle fraction (FPF) was 66.24 ± 0.73%, 66.20 ± 0.89%, 66.07 ± 1.42%, 66.18 ± 0.79%, and 66.29 ± 0.70%, respectively. The MMAD for inhalation solutions needs to be 1-5 µm, which indicates that the components of TIS are suitable for inhalation. It is important to control the particle size of targeted drugs to ensure that the drug is delivered to the appropriate target tissue. In vitro experiments indicated that TIS exhibited high rates of deposition in lung tissue, thus indicating that pulmonary delivery systems may represent a good therapeutic option for patients.

Therapeutic effects of total saponins of Panax notoginseng on atherosclerosis in mice / 中国药理学通报

Aim To investigate the therapeutic effects of total saponins of Panax notoginseng( PNS) on ather-osclerosis( AS) in ApoE knockout mice. Methods According to TC level, ApoE knockout mice were ran-domly assigned into six groups. Control group was fed with normal diet, and the other groups were fed with high-fat diet. After 16 weeks, mouse serum and aortas were harvested. The formation of atherosclerotic plaque was analyzed by oil red staining, the proportion of pathological lesion and the apoptosis of endothelial cells in left ventricular outflow tract were analyzed by HE staining and TUNEL. The serum level of lipids profiles, oxLDL-C were detected, and the mRNA ex-pressions of ICAM-1, VCAM-1, iNOS, eNOS, IL-1, IL-6 and TNF-α were detected by qPCR. Results In model group, the serum content of TC, LDL-C and HDL-C significantly increased(P<0.01); the area of atherosclerotic plaque significantly increased ( P <0.01) ; and the apoptosis of endothelial cells and the proportion of pathological lesion of left ventricular out- flow tract significantly increased(P<0.01). Also, the mRNA expression of ICAM-1, VCAM-1, iNOS, IL-1, IL-6 and TNF-α in model group increased. Compared with model group, the serum content of TC, LDL-C and HDL-C decreased after administration of PNS. The serum content of oxLDL-C was significantly reduced in PNS groups( P <0.01, P <0.05 ) . The apoptosis of endothelial cells significantly declined as well ( P <0.01, P <0.05 ) . The area of atherosclerotic plaque decreased after administration of PNS. The mRNA ex-pression of ICAM-1, VCAM-1, iNOS, IL-1, IL-6 and TNF-α in PNS groups were down-regulated. Conclu-sions In ApoE-KO mouse model, PNS plays a role in the therapy of AS, which may be due to its modulating lipid metabolism, protecting vascular endothelium, de-creasing inflammation and inhibiting adhesion of im-mune cells.

[Protective effect of total saponins of Panax notoginseng combined with total flavonoids of epimedium on D-galactose-incuced senescence of H9c2 cell].

To investigate the protective effect of Panax notoginseng saponins combined with total flavonoids of epimedium on D-gal-induced senescence of H9c2 cells and explore its underlying mechanisms. The 50 mol•L⁻¹ D-gal was used to induce H9c2 cells senescence. Different concentrations of TPNS, TFE, and TPNS combined with TFE were used for 4 hours for pre-treatment. D-gal was used to stimulate H9c2 cardiac muscle cells for 24 h. Then in order to determine the best combined scheme, MTT was used to detect cell viability. Cell senescence was identified by ß-galactosidase staining. Levels of reactive oxygen species(ROS) was observed by DCFH-DA detection. The changes of mitochondrial membrane potential were identified by JC-1 detection. Protein levels of silentmating type information regulation 2 Homolog-1(SIRT1), peroxisomal proliferator-activated receptor-coactivator 1α(PGC-1α) and silentmating type information regulation 2 Homolog-3(SIRT3) were detected by western blot analysis. The results showed that TPNS(5 mg•L⁻¹) combined with TFE(5 mg•L⁻¹) had significant synergistic effect on H9c2 myocardial cell proliferation(Q=1.154), so 5 mg•L-1TPNS combined with 5 mg•L⁻¹ TFE was determined as the best scheme. The quantity of ß-galactosidase staining and the fluorescence intensity of ROS were apparently decreased in 5 mg•L⁻¹ TPNS combined with 5 mg•L⁻¹ TFE scheme. Meanwhile, it markedly increased the florescence intensity of mitochondrial membrane potential and enhanced the protein expression of SIRT1, PGC-1α and SIRT3. TPNS combined with TFE could protect H9c2 cells from D-gal-induced senescence. The mechanism might be related to adjusting the signal pathways of SIRT1/PGC-1α, SIRT3, adjusting the structure and function of mitochondria and reducing oxidative stress injury.

Panax notoginseng saponins suppress radiation-induced osteoporosis by regulating bone formation and resorption.

BACKGROUND: While radiation-based therapies are effective for treating numerous malignancies, such treatments can also induce osteoporosis. PURPOSE: We assessed the antiosteoporotic properties of total saponins extracted from the leaves of Panax notoginseng (LPNS) in a mouse model of radiation-induced osteoporosis and in vitro. STUDY DESIGN/METHODS: The bone mineral densities, the marker of bone formation and resorption, and inflammatory factors were measured in vivo. Cell proliferation and differentiation were detected in vitro. RESULTS: The results showed that bone mineral densities in irradiated mice administered LPNS were significantly increased compared to those in irradiated mice which had not received LPNS. LPNS attenuated the inflammation caused by irradiation, and significantly increased blood serum AKP activity, the mRNA levels of RUNX2 and osteoprotegerin, and the numbers of CFU-Fs formed by bone marrow cells collected from irradiated mice. In contrast, LPNS decreased the numbers of osteoclast precursor cells (CD117(+)/RANKL(+) cells and CD71(+)/CD115(+) cells) and the mRNA levels of TRAP and ATP6i. These results suggest that LPNS functions as a negative regulator of bone resorption. In vitro assays showed that LPNS promoted the differentiation of bone marrow mesenchymal stem cells and mononuclear cells into osteoblasts and osteoclasts, respectively, but had no effect on osteoclast activation. CONCLUSION: These results demonstrate that LPNS has significant antiosteoporotic activity, which may warrant further investigations concerning its therapeutic effects in treating radiation-induced osteoporosis.

Antioxidative effects of Panax notoginseng saponins in brain cells.

Oxidative stress resulting from accumulation of reactive oxygen species (ROS) is involved in cell death associated with neurological disorders such as stroke, Alzheimer's disease and traumatic brain injury. Antioxidant compounds that improve endogenous antioxidant defenses have been proposed for neural protection. The purpose of this study was to investigate the potential protective effects of total saponin in leaves of Panax notoginseng (LPNS) on oxidative stress and cell death in brain cells in vitro. Lactate dehydrogenase (LDH) assay indicated that LPNS (5 µg/ml) reduced H2O2-induced cell death in primary rat cortical astrocytes (23±8% reduction in LDH release vs. control). Similar protection was found in oxygen and glucose deprivation/reoxygenation induced SH-SY5Y (a human neuroblastoma cell line) cell damage (78±7% reduction vs. control). The protective effects of LPNS in astrocytes were associated with attenuation of reactive oxygen species (ROS) accumulation. These effects involved activation of Nrf2 (nuclear translocation) and upregulation of downstream antioxidant systems including heme oxygenase-1 (HO-1) and glutathione S-transferase pi 1 (GSTP1). These results demonstrate for the first time that LPNS has antioxidative effects which may be neuroprotective in neurological disorders.