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BACKGROUND: Inflammatory microenvironment of nucleus pulposus cells is an important factor to promote nucleus pulposus degeneration. Inflammatory factors amplify the cascade of inflammation by activating the nuclear factor-κB signaling pathway to form a vicious cycle and accelerate the process of nucleus pulposus degeneration. It could delay the progression of intervertebral disc degeneration by inhibiting the activity of nuclear factor-κB signaling pathway. OBJECTIVE: To investigate the mechanism of Pheretima extract on nucleus pulposus cell degeneration. METHODS: Pheretima active ingredients were extracted by cold dipping. The cell counting kit-8 method was used to detect the effects of 0, 25, 50, 100, 200, 400 mg/L Pheretima extract on rat nucleus pulposus cell activity, and then suitable drug concentrations were chosen for following research. Tumor necrosis factor-α (TNF-α) was used to stimulate nucleus pulposus cells to induce the nucleus pulposus cell degeneration model. Pheretima extracts (50, 100, 200 mg/L) were used to treat the cell model. Western blot was used to detect the expression of Aggrecan, Collagen II, TNF-α and interleukin-6. RT-qPCR was used to detect mRNA expression of TNF-α and interleukin-6. Immunofluorescence was used to detect the nuclear expression of P65 in the nucleus pulposus cells. RESULTS AND CONCLUSION: Compared with the blank group (0 mg/L), 400 mg/L Pheretima extract inhibited the activity of nucleus pulposus cells, and 50, 100, 200 mg/L extracts of Pheretima were used for subsequent experimental research. Compared with the normal group, the expression of Aggrecan and Collagen II in the model group was reduced, the protein and mRNA expression levels of TNF-α and interleukin-6 were up-regulated, and P65 expression increased in the nucleus. Compared with the model group, Pheretima extract could increase the expression of Aggrecan and Collagen II, down-regulate the protein and mRNA levels of TNF-α and interleukin-6, and reduce P65 expression in the nucleus. To conclude, Pheretima extract can reduce the expression of inflammatory factors, increase the synthesis of extracellular matrix and inhibit nuclear factor-κB pathway activity. Pheretima extract may ameliorate nucleus pulposus cell degeneration in the intervertebral disc via the nuclear factor-κB signaling pathway.
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Objective:To compare the effect and mechanisms of modified Erchentang and Xuefu Zhuyutang on high-fat diet-induced apolipoprotein-E knockout (ApoE-/-) mice nonalcoholic fatty liver disease (NAFLD). Method:Ten C57/BL6J mice were taken as normal control group and fed with normal feed. Totally 30 ApoE-/- mice were fed with high-fat diet to establish a disease model for 4 weeks. After 4 weeks, the 30 ApoE-/- mice were divided into model group, Xuefu Zhuyutang group (hereinafter referred to as Huoxue group) and modified Erchentang group (hereinafter referred to as Huatan group) by random number table method, with 10 in each group. The normal group and the model group were intragastrically administered with normal saline. The drug-administered group was intragastrically administered at a dosage that was ten times of the adult dose, once a day, for 8 weeks. Serum and liver were collected after the end of the 12-week experiment. The serum lipid and liver function levels of each group were measured, and the liver pathological morphology was observed. Protein and mRNA expressions of liver inflammatory mediators interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), matrix metalloproteinase-9 (MMP-9), monocyte chemotactic factor-1 (MCP-1) were detected by Real-time fluorescence quantitative polymerase chain reaction(Real-time PCR) and Western blot. Result:The results of serum lipids and liver function showed that compared with the normal group, serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in the model group were significantly increased, while serum high-density lipoprotein (HDL) was significantly reduced (P<0.01). Compared with the model group, serum TG ，LDL and ALT were significantly decreased, HDL was significantly increased in the Huoxue group (P<0.05). The serum levels of TC, TG， LDL, AST and ALT in the Huatan group were significantly decreased，HDL was significantly increased (P<0.05，P<0.01), and TG was decreased. The mice serum HDL in the Huatan group was higher than that in the Huoxue group. The serum ALT in the Huoxue group was lower than that in the Huatan group. The pathological observation showed that compared with the normal group, hepatocytes in the model group had severe steatosis with many lipid droplet vacuoles, suggesting that the mouse NAFLD model was successful. Compared with the model group, each administration group alleviated hepatocyte steatosis, with no significant difference between the two administration groups. Western blot and Real-time PCR results showed that compared with the normal group, protein and mRNA expression levels of TNF-α, IL-1β, MCP-1, and MMP-9 in the model group were significantly increased (P<0.05，P<0.01). Compared with the model group, the Huoxue group significantly down-regulated the expressions of IL-1β, MCP-1 protein and MCP-1 mRNA(P<0.05，P<0.01). The Huatan group significantly reduced the expressions of IL-1β, TNF-α, MMP-9, MCP-1 protein, TNF-α and MMP-9 mRNA(P<0.05，P<0.01). Conclusion:Modified Erchentang and Xuefu Zhuyutang can alleviate the therapeutic effect of NAFLD mice to a certain extent, modified Erchentang has a better therapeutic effect.
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Objective To investigate the effects of changes in elastic modulus of dental implants on stress distributions in implants and peri-implant bone by 3D finite element analysis, so as to supply experimental evidence for new implant system. Methods The model of the mandible with implant bone was constructed based on CT data. The elastic modulus of implants was set as 110, 90, 70, 55 and 40 GPa, respectively. The model was applied with static load of 300 N in vertical direction, 100 N in horizontal direction and 130 N in oblique direction, respectively, to stimulate occlusal state. The stresses on different parts of implants with different elastic modulus and peri-implant bone under 3 kinds of loads were calculated and analyzed. Results As the elastic modulus of implants declined, stresses in cortical bone around implants under horizontal and oblique loads decreased, and stresses in the implants showed a decreasing tendency as well. Conclusions The decrease in elastic modulus of implants can benefit the transferring of load from the implants to the surrounding bone, and reduce the risk of long-term implant failure.
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<p><b>OBJECTIVE</b>To evaluate the biocompatibility of nano-silver base inorganic antibacterial agents and compare the cytotoxicity in vitro among six types of nano-silver base inorganic antibacterial agents.</p><p><b>METHODS</b>FUMAT T200-4, HN300, Novaron, Kangwang, MOD and SR1000 were diluted to different concentrations, such as 100 g/L, 50 g/L, 25 g/L and 12.5 g/L. The cytotoxicity in vitro of these agents on rat's fibroblast was assayed with MTT method. And the grades of cytotoxicity were compared.</p><p><b>RESULTS</b>High concentrations of nano-silver base inorganic antibacterial agents had cytotoxic effects on rat's fibroblasts L-929. As the concentration decreased, the cytotoxicity decreased. No cytotoxic effects were observed at or below the concentration of 25 g/L. FUMAT T200-4, Kongwang and SR1000, with the carrier of phosphate zirconium, had less cytotoxity than the others.</p><p><b>CONCLUSIONS</b>Nano-Silver base inorganic antibacterial agents, such as FUMAT T200-4, Kangwang, SR1000, have good biocompatibility. And they have the possibility of clinical application. The safe concentration of these agents is at or below 25 g/L.</p>