Bu zhong Yiqi Decoction ameliorates mild cognitive impairment by improving mitochondrial oxidative stress damage via the SIRT3/MnSOD/OGG1 pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Bu-Zhong-Yi-Qi Decoction(BZYQD) is a traditional formula commonly used in China, known for its effects in tonifying Qi and raising Yang. It can relieve symptoms of cognitive impairment such as forgetfulness and lack of concentration caused by qi deficiency, which is common in aging and debilitating. However, much of the current research on BZYQD has been focused on its impact on the digestive system, leaving its molecular mechanisms in improving cognitive function largely unexplored. AIM OF THE STUDY: Cognitive decline in the aging central nervous system is intrinsically linked to oxidative damage. This study aims to investigate the therapeutic mechanism of BZYQD in treating mild cognitive impairment caused by qi deficiency, particularly through repair of mitochondrial oxidative damage. MATERIALS AND METHODS: A rat model of mild cognitive impairment (MCI) was established by administering reserpine subcutaneously for two weeks, followed by a two-week treatment with BZYQD/GBE. In vitro experiments were conducted to assess the effects of BZYQD on neuronal cells using a H2O2-induced oxidative damage model in PC12 cells. The open field test and the Morris water maze test evaluated the cognitive and learning memory abilities of the rats. HE staining and TEM were employed to observe morphological changes in the hippocampus and its mitochondria. Mitochondrial activity, ATP levels, and cellular viability were measured using assay kits. Protein expression in the SIRT3/MnSOD/OGG1 pathway was analyzed in tissues and cells through western blotting. Levels of 8-OH-dG in mitochondria extracted from tissues and cells were quantified using ELISA. Mitochondrial morphology in PC12 cells was visualized using Mito Red, and mitochondrial membrane potential was assessed using the JC-1 kit. RESULTS: BZYQD treatment significantly improved cognitive decline caused by reserpine in rats, as well as enhanced mitochondrial morphology and function in the hippocampus. Our findings indicate that BZYQD mitigates mtDNA oxidative damage in rats by modulating the SIRT3/MnSOD/OGG1 pathway. In PC12 cells, BZYQD reduced oxidative damage to mitochondria and mtDNA in H2O2-induced conditions and was associated with changes in the SIRT3/MnSOD/OGG1 pathway. CONCLUSION: BZYQD effectively counteracts reserpine-induced mild cognitive impairment and ameliorates mitochondrial oxidative stress damage through the SIRT3/MnSOD/OGG1 pathway.

The RIG-I Signal Pathway Mediated Panax notoginseng Saponin Anti-Inflammatory Effect in Ischemia Stroke.

Panax notoginseng saponins (PNS), the main bioactive constituents of a traditional Chinese herb Panax notoginseng, were commonly used for ischemic stroke in China. However, the associated cellular and molecular mechanisms of PNS have not been well examined. This study aimed to decipher the underlying molecular target of PNS in the treatment of cerebral ischemia. The oxygen-glucose-deprived (OGD) model of rat brain microvascular endothelial cells (BMECs) was used in this study. The alteration of gene expression in rat BMECs after PNS treatment was measured by microarray and indicated that there were 38 signaling pathways regulated by PNS. Among them, RIG-I receptor and related signaling molecules TNF receptor-associated factor 2 (Traf2) and nuclear factor-kappa B (NF-κB) were significantly suppressed by PNS, which was verified again in OGD-induced BMECs measured by FQ-PCR and western blotting and in middle cerebral artery occlusion (MCAO) rats measured by immunohistochemistry. The levels of TNF-α, IL-8, and the downstream cytokines regulated by RIG-I receptor pathway were also decreased by PNS. Meanwhile, the neurological evaluation, hematoxylin and eosin (HE) staining, and Evans blue staining were conducted to evaluate the effect of PNS in MCAO rats. Results showed PNS significantly improved functional outcome and cerebral vascular leakage. Flow cytometry showed the number of the inflammatory cells infiltrated in brain tissue was decreased in PNS treatment. Our results identified that RIG-I signaling pathway mediated anti-inflammatory properties of PNS in cerebral ischemia, which provided the novel insights of PNS application in clinics.

Gan Shen Fu Fang ameliorates liver fibrosis in vitro and in vivo by inhibiting the inflammatory response and extracellular signal-regulated kinase phosphorylation.

BACKGROUND: Liver fibrosis is a common health problem worldwide and there is still a lack of effective medicines. The Chinese herbal medicine, Gan Shen Fu Fang (GSFF) is composed of salvianolic acid B and diammonium glycyrrhizinate. In this study, we observed the effects of GSFF on liver fibrosis in vivo and in vitro in an attempt to provide some hope for the treatment. AIM: To observe the effects of GSFF on liver fibrosis in vivo and in vitro and investigate the mechanism from the perspective of the inflammatory response and extracellular signal-regulated kinase (ERK) phosphorylation. METHODS: Common bile duct-ligated rats were used for in vivo experiments. Hepatic stellate cells-T6 (HSC-T6) cells were used for in vitro experiments. Hematoxylin and eosin staining and Masson staining, biochemical assays, hydroxyproline (Hyp) assays, enzyme-linked immunoasorbent assay and western blotting were performed to evaluate the degree of liver fibrosis, liver function, the inflammatory response and ERK phosphorylation. The CCK8 assay, immunofluorescence and western blotting were applied to test the effect of GSFF on HSC-T6 cell activation and determine whether GSFF had an effect on ERK phosphorylation in HSC-T6 cells. RESULTS: GSFF improved liver function and inhibited liver fibrosis in common bile duct-ligated rats after 3 wk of treatment, as demonstrated by histological changes, hydroxyproline assays and collagen I concentrations. GSFF alleviated inflammatory cell infiltration and reduced the synthesis of pro-inflammatory cytokines [tumor necrosis factor-α (TNF-α) and interlukin-1ß] and NF-κB. In addition, GSFF decreased ERK phosphorylation. In vitro, GSFF inhibited the viability of HSC-T6 cells with and without transforming growth factor ß1 (TGF-ß1) stimulation and decreased the synthesis of collagen I. GSFF had the greatest effect at a concentration of 0.5 µmol/L. GSFF inhibited the expression of α-smooth muscle actin (α-SMA), a marker of HSC activation, in HSC-T6 cells. Consistent with the in vivo results, GSFF also inhibited the phosphorylation of ERK and downregulated the expression of NF-κB. CONCLUSION: GSFF inhibited liver fibrosis progression in vivo and HSC-T6 cell activation in vitro. These effects may be related to an alleviated inflammatory response and downregulated ERK phosphorylation.

Smooth Muscle α-Actin Deficiency Leads to Decreased Liver Fibrosis via Impaired Cytoskeletal Signaling in Hepatic Stellate Cells.

In the liver, smooth muscle α-actin (SM α-actin) is up-regulated in hepatic stellate cells (HSCs) as they transition to myofibroblasts during liver injury and the wound healing response. Whether SM α-actin has specific functional effects on cellular effectors of fibrosis such as HSC is controversial. Here, the relationship between SM α-actin and type 1 collagen expression (COL1A1), a major extracellular matrix protein important in liver fibrosis, is investigated with the results demonstrating that knockout of SM α-actin leads to reduced liver fibrosis and COL1 expression. The mechanism for the reduction in fibrogenesis in vivo is multifactorial, including not only a reduction in the number of HSCs, but also an HSC-specific reduction in COL1 expression in Acta2-deficient HSCs. Despite a compensatory increase in expression of cytoplasmic ß-actin and γ-actin isoforms in Acta2-/- HSCs, defects were identified in each transforming growth factor beta/Smad2/3 and ET-1/Erk1/2 signaling in Acta2-/- HSCs. These data not only suggest a molecular link between the SM α-actin cytoskeleton and classic fibrogenic signaling cascades, but also emphasize the relationship between SM α-actin and fibrogenesis in hepatic myofibroblasts in vivo.

Glytan decreases portal pressure via mesentery vasoconstriction in portal hypertensive rats.

AIM: To investigate the effects of Glytan on splanchnic hemodynamics and its reduction of portal pressure in portal hypertensive rats. METHODS: Glytan (Ganluotong in Chinese), is composed of salvianolic acid B and diammonium glycyrrhizinate. Portal hypertension (PHT) was induced in the rats by common bile duct ligation (BDL). Hemodynamic studies were performed using the colored microsphere method. Radioimmunoassay (RIA) was used to determine endothelin (ET)-1 levels in the mesenteric circulation. Western blotting methods were used to investigate the effect of Glytan on ET A receptor (ETAR), ET B receptor (ETBR), endothelial NO synthase (eNOS), G-protein-coupled receptor kinase (GRK)2, and ß-arrestin 2 expression in the mesentery. The mRNA of ETAR and ETBR was determined using real-time polymerase chain reaction. RESULTS: Treatment with Glytan reduced portal pressure (PP) and portal territory blood flow (PTBF) and increased both mean arterial pressure (MAP) and splanchnic vascular resistance (SVR). Especially at 4 wk, PP decreased by about 40%, while MAP increased by 13%, SVR increased by 12%, and PTBF decreased by about 21%. The effect of blood flow reduction was greatest in the mesentery (about 33%) at 4 wk. The mesenteric circulation ET-1 levels of BDL rats were lower and negatively correlated with PP at 4 wk. Glytan can increase mesenteric ET-1 content and inhibit ETBR, eNOS, GRK2, and ß-arrestin 2 expression in the mesentery. Moreover, Glytan showed no effect on the expression of ETAR protein and mRNA. CONCLUSION: The decreased PP and PTBF observed after Glytan treatment were related to increased mesenteric vasoconstriction and increased receptor sensitivity to vasoconstrictor.

A Chinese medicine preparation induces neuroprotection by regulating paracrine signaling of brain microvascular endothelial cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Tong Luo Jiu Nao injection (TLJN), a Chinese medicine preparation, was extracted from the Chinese herbs Panax notoginseng and Gardenia jasminoides. Its pharmacological effect on cerebral ischemia was observed in the study. We previously reported that paracrine signaling of brain microvascular endothelial cells (BMECs) had a direct impact on the survival of neurons in mimicked cerebral ischemia in vitro. The current study was designed to investigate whether paracrine signaling of BMECs could be regulated by drug to achieve neuroprotection. MATERIALS AND METHODS: First, an in vitro model of cerebral ischemia in BMECs or neurons was established by oxygen-glucose-deprivation (OGD). TLJN was used as a medicine of intervention. Injured neurons were cultured in the conditioned media from normal and injured BMECs treated with TLJN. The changes in neurons, including the expression of N-methyl-D-aspartate receptor 1(NMDAR1), Ca(2+) concentration, cytochrome c release, the mitochondrial membrane potential, were determined by the immunofluorescence staining and molecular Probes. The content of Vascular endothelial growth factor (VEGF) and platelet activating factor (PAF) in various BMECs were also examined by Western blotting and Elisa. RESULTS: The results showed the activity of injured neurons was significantly increased when they were grown in conditioned media of normal or injured BMECs treated with TLJN, compared with that of normal or injured BMECs. These changes include a decrease of Ca(2+) concentration, of NMDAR1 expression, and of cytochrome c release, also an increase of the mitochondrial membrane potential. Moreover, the VEGF expression was up-regulated and the PAF expression was down-regulated by TLJN in BMECs. CONCLUSION: The results suggest that a neuroprotective effect of TLJN could be achieved by regulating paracrine signaling of BMECs, which could in part be explained by a TLJN-induced up-regulation of VEGF and a down-regulation of PAF in BMECs. Therefore, regulating the paracrine of BMECs could be the important target of the drug action on injured-neurons, which may be a novel path for therapeutic intervention in ischemic injury.

Effect of tongluojiunao injection made from sanqi (Radix Notoginseng) and zhizi (Fructus Gardeniae) on brain microvascular endothelial cells and astrocytes in an in vitro ischemic model.

OBJECTIVE: To explore the effect of Tongluojiunao injection (TLJN) prepared with Sanqi (Radix Notoginseng) and Zhizi (Fructus Gardeniae) on the interaction between brain microvascular endothelial cells (BMECs) and astrocytes in an in vitro ischemic model. METHODS: First, an in vitro model of cerebral ischemia in BMECs or astrocytes was established by oxygen-glucose deprivation (OGD). TLJN was used as a medicine of intervention. The OGD-injured BMECs were cultured in various astrocyte-conditioned media. Cell activity, alkaline phosphatase (AKP) and γ-glutamyl transpeptidase (γ-GT) activity, interleukin-1 beta (IL-1ß), and tumor necrosis factor alpha (TNF-α) content in BMECs were determined. Additionally, OGD-injured astrocytes were cultured in various BMEC-conditioned media. Cell activity, as well as expression of brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor (GDNF) in astrocytes, were detected. RESULTS: The results of paracrine signaling of normal BMECs or astrocytes showed a protective effect on each other: conditioned media from normal astrocytes improved cell viability, AKP, and γ-GT activity, and reduced IL-1ß and TNF-α content of injured BMECs; conditioned media from normal BMECs improved cell viability and expression of BDNF and GDNF in injured astrocytes. However, once the BMECs or astrocytes were injured by OGD, the protective effect decreased or disappeared. The above-mentioned protective induction was effectively recovered by TLJN intervention. CONCLUSION: The therapeutic benefit of TLJN was achieved by recovering two-way induction between BMECs and astrocytes, enhancing activity of injured BMECs and astrocytes, stabilizing enzymatic barriers, promoting expression of neurotrophic factors, and inhibiting inflammatory cytokines.

Increased endothelin receptor B and G protein coupled kinase-2 in the mesentery of portal hypertensive rats.

AIM: To elucidate the mechanisms of mesenteric vasodilation in portal hypertension (PHT), with a focus on endothelin signaling. METHODS: PHT was induced in rats by common bile duct ligation (CBDL). Portal pressure (PP) was measured directly via catheters placed in the portal vein tract. The level of endothelin-1 (ET-1) in the mesenteric circulation was determined by radioimmunoassay, and the expression of the endothelin A receptor (ETAR) and endothelin B receptor (ETBR) was assessed by immunofluorescence and Western blot. Additionally, expression of G protein coupled kinase-2 (GRK2) and ß-arrestin 2, which influence endothelin receptor sensitivity, were also studied by Western blot. RESULTS: PP of CBDL rats increased significantly (11.89 ± 1.38 mmHg vs 16.34 ± 1.63 mmHg). ET-1 expression decreased in the mesenteric circulation 2 and 4 wk after CBDL. ET-1 levels in the systemic circulation of CBDL rats were increased at 2 wk and decreased at 4 wk. There was no change in ETAR expression in response to CBDL; however, increased expression of ETBR in the endothelial cells of mesenteric arterioles and capillaries was observed. In sham-operated rats, ETBR was mainly expressed in the CD31⁺ endothelial cells of the arterioles. With development of PHT, in addition to the endothelial cells, ETBR expression was noticeably detectable in the SMA⁺ smooth muscle cells of arterioles and in the CD31⁺ capillaries. Following CBDL, increased expression of GRK2 was also found in mesenteric tissue, though there was no change in the level of ß-arrestin 2. CONCLUSION: Decreased levels of ET-1 and increased ETBR expression in the mesenteric circulation following CBDL in rats may underlie mesenteric vasodilation in individuals with PHT. Mechanistically, increased GRK2 expression may lead to desensitization of ETAR, as well as other vasoconstrictors, promoting this vasodilatory effect.