Effect and mechanism of Poria cocos polysaccharides on myocardial cell apoptosis in rats with myocardial ischemia-reperfusion injury by regulating Rho-ROCK signaling pathway / 中国中药杂志

This study aimed to investigate the effect and underlying mechanism of Poria cocos polysaccharides(PCP) on myocardial cell apoptosis in the rat model of myocardial ischemia-reperfusion injury(MI/RI). Male SPF-grade SD rats were randomly divided into a sham group(saline), a model group(saline), low-and high-dose PCP groups(100 and 200 mg·kg~(-1)), and a fasudil group(10 mg·kg~(-1)), with 16 rats in each group. Except for the sham group, the other four groups underwent left anterior descending coronary artery ligation for 30 min followed by reperfusion for 2 h to establish the MI/RI model. The myocardial infarct area was assessed by TTC staining. Histological changes were observed through HE staining. Myocardial cell apoptosis was evaluated using TUNEL staining. Serum lactate dehydrogenase(LDH), creatine kinase MB(CK-MB), interleukin-1β(IL-1β) and IL-18 levels, myocardial superoxide dismutase(SOD) activity and malondialdehyde(MDA) levels were detected by ELISA. Protein expression of B-cell lymphoma 2(Bcl-2), Bcl-2 associated X protein(Bax), cleaved caspase-3, Ras homolog gene A(RhoA), myosin phosphatase target subunit 1(MYPT-1), phosphorylated MYPT-1(p-MYPT-1), and Rho-associated coiled-coil forming kinase 1(ROCK 1) were measured by Western blot. Pathological staining of myocardial tissue revealed that in the model group, there was focal necrosis of myocardial tissue, myocardial cell swelling, unclear boundaries, and neutrophil infiltration. These pathological changes were alleviated in the low-and high-dose PCP groups and the fasudil group. Compared with the model group, the low-and high-dose PCP groups and the fasudil group showed significantly reduced myocardial infarct area and myocardial cell apoptosis rate. Compared with the sham group, the model group exhibited elevated serum LDH, CK-MB, IL-1β and IL-18 levels, increased MDA levels, relative protein expression of Bax, cleaved caspase-3, RhoA, ROCK1 and p-MYPT-1, and decreased myocardial SOD levels and Bcl-2 protein expression. Compared with the model group, the PCP groups and the fasudil group showed lowered serum LDH, CK-MB, IL-1β and IL-18 levels, decreased MDA levels, relative protein expression of Bax, cleaved caspase-3, RhoA, ROCK1 and p-MYPT-1, and increased myocardial SOD levels and Bcl-2 protein expression. PCP exhibited a certain preventive effect on myocardial tissue pathological damage and myocardial cell apoptosis in MI/RI rats, possibly related to the inhibition of the Rho-ROCK signaling pathway activation, thereby reducing oxidative stress and inflammatory responses.

Study on the mechanism of Poria cocos polysaccharides on the regulation of gluconeogenesis in liver of type 2 diabetic mellitus model rats / 中国药房

OBJECTIVE To investigate the effect and mechanism of Poria cocos polysaccharides on the regulation of blood glucose in type 2 diabetes mellitus （T2DM）model rats by phosphatidylinositol 3-kinase（PI3K）/protein kinase B （Akt）/forked box transcription factor O 1（FoxO1）pathway. METHODS SD rats were randomly divided into blank control group （no modeling ，no administration），model group （modeling，no administration ），metformin group （modeling，200 mg/kg）and P. cocos polysaccharide low-dose，medium-dose and high-dose groups （modeling，100，200，400 mg/kg），8 in each group. Except for blank control group ， other groups were given high fat diet combined with streptozotocin to construct the model of T 2DM rats. At the same time ， administration groups were given relevant dose of medicine intragastrically ，and blank control group and model group were given constant volume of water intragastrically ，once a day ，for consecutive 42 days. During the experiment ，general condition and bodyweight of rats were observed every day ；fasting blood glucose （FBG）of rats were collected ，and oral glucose tolerance test were conducted and area under curve （AUC）was calculated the day before last administration. After last medication ，the heart ，liver， kidney organ index were calculated ；the levels of HbA 1c，TC，TG，MDA，SOD，GSH-Px and hepatic glycogen content were detected. HE staining was used to observe the pathological changes of liver and pancreatic tissue ，and the pathological grade score was calculated. Western blot assay was used to detect the protein expressions of p-PI 3K，p-Akt，p-FoxO1， PEPCK and G 6Pase in liver tissues. RESULTS Compared with blank control group ，the rats of model group suffered cc1965@163.com from polydipsia ，polyphagia and polyuria ；the body weight ， the levels of SOD and GSH-Px ，the protein expressions of p-PI 3K，p-Akt and p-FoxO 1 were significantly decreased （P＜0.05）；liver and kidney organ index ，blood glucose level at 0，0.5 and 2 hours after intragastric administration of glucose solution ，AUC， FBG，HbA1c，serum levels of MDA ，TC，TG and hepatic glycogen content ，liver and pancreatic pathological grade score ，the protein expressions of PEPCK and G 6Pase were all increased significantly （P＜0.05）. Compared with model group ，the general condition of rats in P. cocos polysaccharide groups were all improved ，and all of above indicators had been reversed to varying degrees. CONCLUSIONS P. cocos polysaccharide can downregulate protein expressions of PEPCK and G 6Pase which are key enzymes of gluconeogenesis ，inhibit hepatic gluconeogenesis ，effectively decrease blood glucose levels and regulate glucolipid metabolism in T 2DM model rats by weakening oxidative stress and upregulating PI 3K/Akt/FoxO1 pathway.

Extracts of Poria cocos polysaccharides improves alcoholic liver disease in mice via CYP2E1 and NF-κB inflammatory pathways / 中国中药杂志

The present study investigated the effect of extract of Poria cocos polysaccharides(PCP) on cytochrome P450 2 E1(CYP2 E1) and nuclear factor κB(NF-κB) inflammatory signaling pathways in alcoholic liver disease(ALD) mice and explored its protective effect and mechanism. Sixty male C57 BL/6 N mice of SPF grade were randomly divided into a control group, a model group, a positive drug group(bifendate, 200 mg·kg~(-1)), and high-(200 mg·kg~(-1)) and low-dose(50 mg·kg~(-1)) PCP groups. Gao-binge mo-del was induced and the mice in each group were treated correspondingly. Liver morphological and pathological changes were observed and organ index was calculated. Serum levels of alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were detected. Malondialdehyde(MDA) and superoxide dismutase(SOD) in liver tissues were detected by assay kits. The levels of interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) were detected by ELISA. The activation of macrophages was observed by immunofluorescence staining and protein expression of CYP2 E1, Toll-like receptor 4(TLR4), NF-κB p65, and phosphorylated NF-κB p65(p-NF-κB p65) were analyzed by Western blot. The ALD model was properly induced. Compared with the model group, the PCP groups significantly improved the pathological injury of liver tissues. Immunofluorescence staining revealed that compared with the model group, the groups with drug intervention showed decreased macrophages in liver tissues. Additionally, the PCP groups showed reduced ALT, AST, MDA, IL-6, and TNF-α(P<0.05), and potentiated activity of SOD(P<0.01). PCP extract has the protective effect against alcoholic liver injury in mice, and the underlying mechanism may be related to the regulation of the expression of CYP2 E1 and inhibition of TLR4/NF-κB inflammatory signaling pathway to reduce oxidative stress and inflammatory injury, thereby inhibiting the development of ALD.

Immunogenicity of Poria cocos polysaccharides PCP-Ⅰand PCP-Ⅱas vaccine adjuvants / 中国药理学与毒理学杂志

OBJECTIVE To investigate the immunogenicities of Poria cocos polysaccharides, PCP-Ⅰand PCP-Ⅱ, as a vaccine adjuvant. METHODS ①Keyhole limpet hemocyanin (KLH) was linked to PCP-Ⅰor PCP-Ⅱrespectively to prepare immuno-antigen KLH-PCP-Ⅰor KLH-PCP-Ⅱ. Bovine serum albumin (BSA) was also linked to PCP-Ⅰor PCP-Ⅱrespectively to prepare screening-antigen. Rabbits were immunized with KLH-PCP-Ⅰor KLH-PCP-Ⅱplus Freund adjuvant by intradermal injection twice, and serum specific antibody titers were determined by ELISA. ②BALB/c mice were immunized with PCP-Ⅰ or PCP-Ⅱ alone intramuscularly twice, and serum polysaccharide antibody titers were determined by ELISA.③BALB/c mice were co-immunized intramuscularly or subcutaneously with PCP-Ⅰor PCP-Ⅱplus hepatitis B surface antigen (HBsAg) or porcine reproductive and respiratory syndrome virus inactivated vaccine (PRRSV) twice, and serum polysaccharide-antibody titers were determined by ELISA. RESULTS ①Serum anti-KLH and anti-polysaccharides (PCP-Ⅰor PCP-Ⅱ) antibodies were pro?duced after rabbits were immunized with KLH-PCP-Ⅰor KLH-PCP-Ⅱplus Freund adjuvant twice.②Serum anti-PCP-Ⅰor anti-PCP-Ⅱantibodies were not found after mice were immunized with PCP-Ⅰand PCP-Ⅱalone twice.③After mice were immunized with HBsAg or PRRSV plus PCP-Ⅰor PCP-Ⅱtwice, serum anti-PCP-Ⅰor anti-PCP-Ⅱantibodies were not found. CONCLUSION PCP-Ⅰand PCP-Ⅱshow weak immunogenicity, which may be quite safe as a vaccine adjuvant.