Quercetin effectively improves LPS-induced intestinal inflammation, pyroptosis, and disruption of the barrier function through the TLR4/NF-κB/NLRP3 signaling pathway in vivo and in vitro.

Background: Inflammatory bowel diseases are characterized by the alterations of the mucosa and gastrointestinal physiology, and the core of these alterations is endothelial cells. Quercetin is a flavonoid presents in some traditional Chinese medicine, plants, and fruits. Its protective effects in several gastrointestinal tumors have been demonstrated, but its effects on bacterial enteritis and pyroptosis-related diseases have rarely been studied. Objective: This study aimed to evaluate the effect of quercetin on bacterial enteritis and pyroptosis. Design: In vitro experiments were performed using rat intestinal microvascular endothelial cells divided into seven groups: control group (no treatment), model group (10 µg/mL lipopolysaccharide (LPS)+1 mM adenosine triphosphate [ATP]), LPS group (10 µg/mL LPS), ATP group (1 mM ATP), and treatment groups (10 µg/mL LPS+1 mM ATP and 5, 10, and 20 µM quercetin). The expression of pyroptosis-associated proteins, inflammatory factors, tight junction proteins, and the percentage of late apoptotic and necrotic cells were measured. In vivo analysis was performed using specific pathogen-free Kunming mice pretreated with quercetin and the water extract of Cacumen Platycladi for 2 weeks followed by 6 mg/kg LPS on day 15. Inflammation in the blood and intestinal pathological changes were evaluated. Results: Quercetin used in vitro significantly reduced the expression of Toll-like receptor 4 (TLR4), NOD-like receptor 3 (NLRP3), caspase-1, gasdermin D, interleukin (IL)-1ß, IL-18, IL-6, and tumor necrosis factor-α. It also inhibited phosphorylation of nuclear factor-kappa B (NF-κB) p65 and increased cell migration and the expression of zonula occludens 1 and claudins, while reduced the number of late apoptotic cells. The in vivo results showed that Cacumen Platycladi and quercetin significantly reduced inflammation, protected the structure of the colon and cecum, and prevent fecal occult blood induced by LPS. Conclusions: These findings suggested the ability of quercetin to reduce inflammation induced by LPS and pyroptosis through TLR4/NF-κB/NLRP3 pathway.

High Glucose Enhances Bupivacaine-Induced Neurotoxicity via MCU-Mediated Oxidative Stress in SH-SY5Y Cells.

Bupivacaine, a typical local anesthetic, induces neurotoxicity via reactive oxygen species regulation of apoptosis. High glucose could enhance bupivacaine-induced neurotoxicity through regulating oxidative stress, but the mechanism of it is not clear. Mitochondrial calcium uniporter (MCU), a key channel for regulating the mitochondrial Ca2+ (mCa2+) influx, is closely related to oxidative stress via disruption of mCa2+ homeostasis. Whether MCU is involved in high glucose-sensitized bupivacaine-induced neurotoxicity remains unknown. In this study, human neuroblastoma (SH-SY5Y) cells were cultured with high glucose and/or bupivacaine, and the data showed that high glucose enhanced bupivacaine-induced MCU expression elevation, mCa2+ accumulation, and oxidative damage. Next, Ru360, an inhibitor of MCU, was employed to pretreated SH-SY5Y cells, and the results showed that it could decrease high glucose and bupivacaine-induced mCa2+ accumulation, oxidative stress, and apoptosis. Further, with the knockdown of MCU with a specific small interfering RNA (siRNA) in SH-SY5Y cells, we found that it also could inhibit high glucose and bupivacaine-induced mCa2+ accumulation, oxidative stress, and apoptosis. We propose that downregulation expression or activity inhibition of the MCU channel might be useful for restoring the mitochondrial function and combating high glucose and bupivacaine-induced neurotoxicity. In conclusion, our study demonstrated the crucial role of MCU in high glucose-mediated enhancement of bupivacaine-induced neurotoxicity, suggesting the possible use of this channel as a target for curing bupivacaine-induced neurotoxicity in diabetic patients.

Tetrahydroxystilbene Glucoside Regulates Proliferation, Differentiation, and OPG/RANKL/M-CSF Expression in MC3T3-E1 Cells via the PI3K/Akt Pathway.

Tetrahydroxystilbene glucoside (TSG) is a unique component of the bone-reinforcing herb Radix Polygoni Multiflori Preparata (RPMP). It has the ability to promote bone formation and protect osteoblasts. However, the underlying mechanism remains unclear. To better understand its biological function, we determined TSG's effect on murine pre-osteoblastic MC3T3-E1 cells by the MTT assay, flow cytometry, FQ-PCR, Western blot, and ELISA. The results showed that TSG caused an elevation of the MC3T3-E1 cell number, the number of cells in the S phase, and the mRNA levels of the runt-related transcription factor-2 (Runx2), osterix (Osx), and collagen type I α1 (Col1a1). In addition, the osteoprotegerin (OPG) mRNA level was up-regulated, while the nuclear factor-κB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) mRNA levels were down-regulated by TSG. Furthermore, TSG activated the phosphoinosmde-3-kinase/protein kinase B (also known as PI3K/Akt) pathway, and blocking this pathway by the inhibitor LY-294002 could impair TSG's functions in relation to the MC3T3-E1 cells. In conclusion, TSG could activate the PI3K/Akt pathway and thus promote MC3T3-E1 cell proliferation and differentiation, and influence OPG/RANKL/M-CSF expression. TSG merits further investigation as a potential therapeutic agent for osteoporosis treatment.

Diphenyleneiodonium Mitigates Bupivacaine-Induced Sciatic Nerve Damage in a Diabetic Neuropathy Rat Model by Attenuating Oxidative Stress.

BACKGROUND: Increased oxidative stress has been linked to local anesthetic-induced nerve injury in a diabetic neuropathy (DN) rat model. The current study explores the effects of diphenyleneiodonium (DPI) chloride, an NADPH oxidase (NOX) inhibitor, on bupivacaine-induced sciatic nerve injury in DN rats. METHODS: A rat DN model was established through high-fat diet feeding and streptozotocin injection. The model was confirmed via testing (i) blood glucose, (ii) hindpaw allodynia responses to von Frey (VF) monofilaments, (iii) paw withdrawal thermal latency (PWTL), and (iv) nerve conduction velocity (NCV). Bupivacaine (Bup, 0.2 mL, 5 mg/mL) was used to block the right sciatic nerve. DPI (1 mg/kg) was injected subcutaneously 24 hours and 30 minutes before the sciatic block. At 24 hours after the block, NCV, various reactive oxygen species, and Caspase-3 were evaluated to determine the extent of sciatic nerve injury. RESULTS: The DN rat model was successfully established. Compared with the DN control group, the postblock values of VF responses (DN-Con, 16.5 ± 1.3 g; DN + Bup, 19.1 ± 1.5 g, P < .001) and PWTL significantly increased (DN-Con, 13.3 ± 1.1 seconds; DN + Bup, 14.6 ± 1.1 seconds, P = .028); the NCV of sciatic nerve was significantly reduced (DN-Con, 38.8 ± 2.4 m/s, DN + Bup, 30.5 ± 2.0 m/s, P = .003), and sciatic nerve injury (as indicated by axonal area) was more severe in the bupivacaine-treated DN group (DN-Con, 11.6 ± 0.3 µm, DN + Bup, 7.5 ± 0.3 µm, P < .001). In addition, DPI treatment significantly improved nerve function (VF responses, 17.3 ± 1.3 g; PWTL, 13.4 ± 1.1 seconds; NCV, 35.6 ± 3.1 m/s) and mitigated loss of axonal area (9.6 ± 0.3 µm). Compared to the DN + Bup group (without DPI), the levels of lipid peroxides and hydroperoxides, as well as the protein expression of NOX2, NOX4, and Caspase-3, were significantly reduced in the DN + Bup + DPI group (P < .05). CONCLUSIONS: Subcutaneous injection of DPI appears to protect against the functional and neurohistological damage of bupivacaine-blocked sciatic nerves in a high-fat diet/streptozotocin-induced DN model.

Neurotoxicity Comparison of Two Types of Local Anaesthetics: Amide-Bupivacaine versus Ester-Procaine.

Local anaesthetics (LAs) may lead to neurological complications, but the underlying mechanism is still unclear. Many neurotoxicity research studies have examined different LAs, but none have comprehensively explored the distinct mechanisms of neurotoxicity caused by amide- (bupivacaine) and ester- (procaine) type LAs. Here, based on a CCK8 assay, LDH assay, Rhod-2-AM and JC-1 staining, 2',7'-dichlorohy-drofluorescein diacetate and dihydroethidium probes, an alkaline comet assay, and apoptosis assay, we show that both bupivacaine and procaine significantly induce mitochondrial calcium overload and a decline in the mitochondrial membrane potential as well as overproduction of ROS, DNA damage and apoptosis (P < 0.05). There were no significant differences in mitochondrial injury and apoptosis between the bupivacaine and procaine subgroups (P > 0.05). However, to our surprise, the superoxide anionic level after treatment with bupivacaine, which leads to more severe DNA damage, was higher than the level after treatment with procaine, while procaine produced more peroxidation than bupivacaine. Some of these results were also affirmed in dorsal root ganglia neurons of C57 mice. The differences in the superoxidation and peroxidation induced by these agents suggest that different types of LAs may cause neurotoxicity via different pathways. We can target more accurate treatment based on their different mechanisms of neurotoxicity.

OGG1 Involvement in High Glucose-Mediated Enhancement of Bupivacaine-Induced Oxidative DNA Damage in SH-SY5Y Cells.

Hyperglycemia can inhibit expression of the 8-oxoG-DNA glycosylase (OGG1) which is one of the key repair enzymes for DNA oxidative damage. The effect of hyperglycemia on OGG1 expression in response to local anesthetics-induced DNA damage is unknown. This study was designed to determine whether high glucose inhibits OGG1 expression and aggravates bupivacaine-induced DNA damage via reactive oxygen species (ROS). SH-SY5Y cells were cultured with or without 50 mM glucose for 8 days before they were treated with 1.5 mM bupivacaine for 24 h. OGG1 expression was measured by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. ROS was estimated using the redox-sensitive fluorescent dye DCFH-DA. DNA damage was investigated with immunostaining for 8-oxodG and comet assays. OGG1 expression was inhibited in cells exposed to high glucose with concomitant increase in ROS production and more severe DNA damage as compared to control culture conditions, and these changes were further exacerbated by bupivacaine. Treatment with the antioxidant N-acetyl-L-cysteine (NAC) prevented high glucose and bupivacaine mediated increase in ROS production and restored functional expression of OGG1, which lead to attenuated high glucose-mediated exacerbation of bupivacaine neurotoxicity. Our findings indicate that subjects with diabetes may experience more detrimental effects following bupivacaine use.

Effect of Fructus Ligustri Lucidi on osteoblastic like cell-line MC3T3-E1.

UNLABELLED: Fructus Ligustri Lucidi, fruits of Ligustrum lucidum Ait. (Oleaceae), has the effects of tonifying the liver and the kidney and strengthening the bones and muscles. In ancient times, Fructus Ligustri Lucidi can be prepared in ethanol or in water. Some active compounds have been found in Fructus Ligustri Lucidi, like Oleanolic acid and Ursolic acid, and Ursolic acid were proved to have osteogenic effects. METHODS AND RESULTS: To prove that Fructus Ligustri Lucidi water extract have osteogenic effects on MC3T3-E1 cells and how these effects work, we used CCK-8 (cell counting kit-8), ELISA (enzyme-linked immunosorbent assay), FQ-PCR (realtime fluorescence quantitative PCR) and western blot assays. After treatment with Fructus Ligustri Lucidi for 48h, 72h, 96h, the cell viability was marked increased, on concentration-dependently and time-dependently pattern. High and low concentrations of Fructus Ligustri Lucidi promoted differentiation of cells. Fructus Ligustri Lucidi could up-regulate OPG and RANKL protein in supernatant at 48h and 72h except for highest concentration (10(-1)mg/ml). Fructus Ligustri Lucidi promote OPG and RANKL mRNA expression at 48h and 72h, while the level of promoting at 72 was higher than 48h. 10(-5)mg/ml of Fructus Ligustri Lucidi up-regulates OPG protein expression and down-regulates RANKL protein expression. After treatment with Fructus Ligustri Lucidi water extract, inhibitors, Fructus Ligustri Lucidi water extract with inhibitors for 72h, inhibitors PD 98059, SB 203580, SP600125 and LY 294002 showed Fructus Ligustri Lucidi-induced cell proliferation and the leakage of OPG proteins effects. Fructus Ligustri Lucidi promoted the protein levels of ERK, p-ERK, p-JNK, p38, pp38, AKT and p-AKT, and inhibited the protein levels of JNK. CONCLUSIONS: Fructus Ligustri Lucidi water extract promoted cell proliferation and differentiation, mRNA and protein expression of OPG and RANKL on MC3T3-E1 cells. The effects of cell proliferation and leakage of OPG related to MAPK and AKT signaling pathways in different ways.

Hyperglycemia magnifies bupivacaine-induced cell apoptosis triggered by mitochondria dysfunction and endoplasmic reticulum stress.

Nerve cell injury associated with apoptosis plays an important role in the development of diabetic peripheral neuropathy (DPN). However, it remains unclear whether preexisting or potential neurocyte damage induced by hyperglycemia increases sensitivity to local anesthetics. SH-SY5Y cells were pretreated with a high concentration of glucose in vitro, to imitate DPN prior to administration of bupivacaine or placebo. Cell viability and apoptosis were investigated with a CCK-8 assay and flow cytometry, respectively. In addition, mitochondrial membrane potential, reactive oxygen species (ROS), mitochondrially generated ROS, and activity of mitochondrial complexes I and III were studied to explore the molecular mechanism of bupivacaine-induced mitochondrial injury. Grp78 and caspase-12 expression were measured by qRT-PCR and Western blot, representing endoplasmic reticulum (ER) stress. Cell structure was also assessed via transmission electron microscopy. Incubation with bupivacaine decreased the activity of mitochondrial complexes I and III; increased ROS production at cell and mitochondrial levels, mitochondrial potential depolarization, and Grp78 and caspase-12 expression at both transcription and translation levels; and affected cell structure, which could be enhanced by glucose pretreatment. These findings indicate that mitochondrial dysfunction and ER stress related to ROS are involved in bupivacaine-induced apoptosis and may be enhanced by glucose administration.

[Effect of lipoxin A(4) on lipopolysaccharide-induced endothelial hyperpermeability in human umbilical vein endothelial cell].

OBJECTIVE: To explore whether lipoxin A(4) (LXA(4))could prevent lipopolysaccharide (LPS)-induced human umbilical vein endothelial cells (HUVEC) monolayer hyperpermeability and its possible mechanism. METHODS: Human umbilical cords were obtained from women with normal pregnancy immediately after delivery from Tongji Hospital Affiliated of Tongji Medical College. Primary HUVEC were isolated from umbilical veins and subcultured, then, HUVEC were divided into four groups:control group; LPS group (10 mg/L of LPS); LPS + LXA(4) group(10 mg/L of LPS and 100 nmol/L of LXA(4)); LPS + LXA(4) + BOC-2 group [10 µmol/L of BOC-2, an effective antagonist of formyl peptide receptor like 1 (FPRL-1)]. All expriments were performed after cells were treated for 24 hours. Endothelial permeability was measured by fluorescein isothiocyan-ate labelled bovine serum albumin (FITC-BSA) clearance across the monolayer; tumor necrosis factor α (TNF-α) mRNA and secretion were detected by reverse transcriplase (RT)-PCR and ELISA assay respectively, and nuclear factor κB (NF-κB) protein change was determined by western blot. RESULTS: (1) LPS induced a significant increase in the permeability [Pa value of LPS group was (183.1 ± 1.7)%], while co-administrating with LXA(4) obviously attenuated this LPS-induced hyperpermeability, Pa value of LPS + LXA(4) group was (103.1 ± 2.2)%, LPS + LXA(4) + BOC-2 group was (162.2 ± 2.8)%, control group was 100%, the permeability of HUVEC monolayer was significantly increased by LPS which was (83.1 ± 1.7)% of control (P < 0.01), however, it was notably inhibited by LXA(4) (P < 0.05); the blockade of FPRL-1 could attenuate the effect of LXA(4), that is, there was no difference between the LPS + LXA(4) + BOC-2 group and the LPS group. (2) After treatment with different concentration of LPS(0, 0.1, 1, 10 mg/L), the mRNA expressions of TNF-α were increased (1.11 ± 0.11, 1.27 ± 0.03, 1.60 ± 0.06, 1.82 ± 0.04, respectively), compared with the control group, at the concentration of 1, 10 mg/L LPS, the difference was statistically significant (P < 0.05). (3) The increased levels of NF-κB and inflammatory mediator TNF-α in the LPS group were both inhibited by LXA(4). Levels of NF-κB protein and TNF-α mRNA secretion in LPS treated group (0.53 ± 0.06 and 0.81 ± 0.09, respectively) were both inhibited by LXA(4)(0.19 ± 0.05 and 0.41 ± 0.07, respectively, and both had significant difference, P < 0.05). (4) Levels of TNF-α in HUVEC culture medium of LPS group [(31.94 ± 0.01) ng/L] was significantly higher than the control group [(18.17 ± 0.03) ng/L, P < 0.05], LPS + LXA(4) group [(15.72 ± 0.07) ng/L] was significantly lower than the LPS group (P < 0.05). CONCLUSION: Our findings demonstrated that LXA(4) could prevent the endothelial cell hyperpermeability induced by LPS in HUVEC under which the possible mechanism was through inhibiting the expression of NF-κB and its related cytokines through receptor-dependent.

[Effect of lipoxin A(4) on lipopolysaccharide-induced oxidant stress in human umbilical vein endothelial cells].

OBJECTIVE: To explore the effects of lipoxin A(4) (LXA(4)) on lipopolysaccharide (LPS)-induced oxidative stress in human umbilical veins endothelial cells (HUVEC) and the possible mechanism. METHODS: Neonatal umbilical cords were obtained from normal term pregnant women with cesarean section within 4 hours and then were used to isolate HUVEC for subculture. HUVEC were divided into four groups:control group; LPS group (10 µg/ml of LPS); LPS + LXA(4) group (10 µg/ml of LPS and 100 nmol/L of LXA(4)); LXA(4) group (100 nmol/L of LXA(4)). All expriments were performed after cells treated for 12 and 24 hours respectively. Immunofluorescence was used to detect the expression of VIII foctor and nuclear translocation of nuclear factor-erythroid-2-related factor 2 (Nrf2); the mRNA expression of Nrf2, heme oxygenase 1 (HO-1) and reduced form of nicotinamide-adenine dinucleotide quinone oxidoreductase-1 (NQO1) were evaluated by reverse transcription-PCR. RESULTS: (1) The flavovirens fluorescence was observed in the cytoplasm under fluorescence microscope, which confirmed the existence of VIII factor which specifically expressed in endothelial cells, especially in HUVEC. (2) Immunofluorescent results showed that in control group, Nrf2 protein expressed in the cytosol rather than in the nucleus. In LPS group, the expression of Nrf2 protein obviously increased in the nucleus while decreased in the cytosol after 12 hours. However, after LPS treatment for 24 hours, Nrf2 expression reduced in the cytosol and nucleus. In co-treatment with LPS and LXA(4) group, the expression of Nrf2 protein was much higher than that in LPS group after 12 hours or 24 hours. Furthermore, Nrf2 protein also mostly expressed in the cytosol in LXA(4) group. (3) After stimulation for 12 hours, compared with control group, the gene expression of Nrf2 and HO-1 were significantly enhanced in LPS group (0.581 ± 0.019 and 0.081 ± 0.009, P < 0.05) and in LPS + LXA(4) group (0.692 ± 0.048 and 0.136 ± 0.018, P < 0.05), the level of NQO1 mRNA in LPS group and LPS + LXA(4) group were 0.381 ± 0.009 (P > 0.05) and 0.574 ± 0.034 (P < 0.05). After treatment for 24 hours, compared with control goup, the gene expressions of Nrf2 and NQO1 were down-regulated in LPS group (0.180 ± 0.017 and 0.472 ± 0.064, P < 0.05). But in LPS + LXA(4) group the expression of Nrf2 and NQO1 were upregulated (0.532 ± 0.051 and 0.830 ± 0.068, P < 0.05, compared with treatment for LPS group). The mRNA expressions of Nrf2, HO-1 and NQO1 were increased in LPS + LXA(4) group compared with LPS group (P < 0.05). In addition, there was no markedly difference in the expressions of Nrf2, HO-1 and NQO1 between control and LXA(4) group after 12 hours and 24 hours (P > 0.05). CONCLUSION: Through activating nuclear translocation of Nrf2 protein from cytoplasm, LXA(4) upregulates the Nrf2 downstream enzymes, such as NQO1 and HO-1 to protect HUVEC against the oxidative stress induced by LPS.

[Observation on therapeutic effect of blood-letting therapy on apoplectic hemiplegia numbness syndrome].

OBJECTIVE: To observe therapeutic effect of blood-letting therapy on apoplectic hemiplegia numbness syndrome and search for clinically effective therapy. METHODS: Ninety and five cases of apoplectic hemiplegia were randomly divided into a treatment group of 55 cases and a control group of 40 cases in order of visiting. The treatment group were treated with tapping Huatuo Jiaji (EX-B2) on the back by plum-blossom needle combined with blood-letting on twelve Well-points or Shixuan (EX-UE 11), once every day, 6 times constituting one course; the control group were treated with routine acupuncture at points of the four limbs, once daily, 12 times constituting one course. After they were treated for 4 courses, their therapeutic effects were observed. RESULTS: The total effective rate was 94.5% in the treatment group and 77.5% in the control group with a significant difference between the two groups (P < 0.01). CONCLUSION: Blood-letting therapy is an effective therapy for post-apoplectic hemiplegia numbness syndrome.