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.

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.

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.

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.