Ginsenoside Rgl regulates NOX2-NLRP1 pathway to reduce hypoxia-reoxygenation injury in PC12 cells / 中国药理学通报

Aim To investigate the effect of ginsenoside Rgl on PC 12 cell hypoxia-reoxygenation injury and its possible mechanism. Methods PC 12 cells were randomly divided into six groups. Except for the blank control group, all the other groups were hypoxia and hypoglycemia for 6 hours, and then reoxygenated and glycosylated for 24 hours to make OGD/R models. Each drug group was given corresponding drugs 2 hours before modeling pretreatment. DCFH-DA method was used to detect the ROS production in cells, Annexin V- FITC/PI double staining method was performed to detect cell apoptosis rate, ELISA method was used to detect LDH activity and IL-1 (3 content in cell supernatant, and Western blot was applied to detect the ex- pression of proteins of N0X2, p22phox, p47phox, NLRPl, ASC, Caspase-1, PSD95, Tau, p-Tau and observe the intervention effect of ginsenoside Rgl. Re sults Tempol, Apocynin and Rgl (5, 10 jjLmol • L"1) groups could significantly inhibit ROS production and apoptosis, reduce LDH release and IL-1 (3 content in cell supernatant; Apocynin and Rgl (5, 10 |xmol • L"1) groups could significantly down-regulate the expression of N0X2, p22phox and p47phox in cells. The Tempol, Apocynin and Rgl (5, 10 jxmol • L"1 ) groups could significantly decrease the protein expression of NLRP1, Caspase-1, ASC, IL-1 (3 and p-Tau, and markedly down-regulate the expression of PSD95 protein. Conclusion Rgl is likely to reduce the is- chemia-reperfusion injury of PC 12 cells by inhibiting the NOX2-NLRP1 pathway.

Lignans with NADPH Oxidase 2 (NOX2)-inhibitory Activity from the Fruits of Schisandra chinensis

An isoform of NADPH oxidase (NOX), NOX2 is a superoxide-generating enzyme involved in diverse pathophysiological events. Although its potential as a therapeutic target has been validated, there is no clinically available inhibitor. Herein, NOX2-inhibitory activity was screened with the constituents isolated from Schisandra chinensis, which has been reported to have antioxidant and reactive oxygen species (ROS)-scavenging effects. Among the partitions prepared from crude methanolic extract, a chloroform-soluble partition showed the highest NOX2-inhibitory activity in PLB-985 cell-based NOX2 assay. A total of twenty nine compounds (1 – 29) were identified from the chloroform fraction, including two first isolated compounds; dimethyl-malate (25) and 2-(2-hydroxyacetyl) furan (27) from this plants. Of these constituents, two compounds (gomisin T, and pregomisin) exhibited an NOX2-inhibitory effect with the IC₅₀ of 9.4 ± 3.6, and 62.9 ± 11.3 µM, respectively. They are confirmed not to be nonspecific superoxide scavengers in a counter assay using a xanthine-xanthine oxidase system. These findings suggest the potential application of gomisin T (6) and other constituents of S. chinensis to inhibit NOX2.

Effects of ursolic acid on activation of NOX2/ROS/NLRP3 inflammasome in liver fibrosis rats / 基础医学与临床

Objective To investigate the effect of ursolic acid(UA) on NOX2/ROS/NLRP3 inflammasome activation in carbon tetrachloride(CCl4)-induced liver fibrosis SD rat,and to observe the improvement of collagen deposition in liver tissues. Methods All rats were randomly divided into 3 group:control group,CCl4model group,UA treatment group. Liver fibrosis model SD rats was established by the CCl4-induced method and half of them was used as UA treatment group. Serum ALT was detected by ALT detection kit.The liver pathology and collagen deposition were ob-served by HE and Sirius-red staining. The mRNA expression of Nox2,Nlrp3,Caspase1,IL-1β in liver tissues was detected by RT-qPCR. The protein expression of NOX2,NLRP3,caspase-1 and IL-1β in liver tissues was detected by Western blot and immunohistochemistry and the ROS generation in liver tissues was detected by DCFH-DA fluores-cence probe. Results Compared with control group,in the CCl4model group,the serum ALT was much higher (P<0.05);the Ishak's fibrosis score and collagen deposition was significantly increased(P<0.05) and mRNA of Nox2, Nlrp3,Caspase1,IL-1β was increased.In addition,both the NOX2,NLRP3,caspase-1 p10 and IL-1β protein expres-sion and ROS level (P<0.05) of CCl4model group were significant increased.Compared with CCl4model group,in the UA treatment group Ishak's fibrosis score,collagen deposition and ALT decreased.Both mRNA expression of the Nox2, Nlrp3,Caspase1,IL-1β and protein expression of NOX2,NLRP3,caspase-1 p10 and IL-1β as well as ROS were signif-icant decreased,but the caspase-1 p45 protein level has no difference among all these groups (P>0.05). Conclusions Ursolic acid attenuates the liver injury and reduces the collagen deposition,which may relate to its inhibitory effects on NOX2/ROS/NLRP3 inflammasome activation to reduce IL-1β releasing.

Protective effect and mechanism of ginsenoside Rg1 on H2O2induced hippocampal neurons aging due to down-regulate NOX2 mediated NLRP1 inflammasome activation in vitro / 中国药理学与毒理学杂志

OBJECTIVE To explore the protective effects and mechanisms of Ginsenoside Rg1 (Rg1) on H2O2-induced hippocampal neurons aging in vitro. METHODS The primary culture hippo-campal neurons(7 d)were randomly placed into six groups:normal control group,H2O2(200 μM)treat-ment group,and H2O2+Rg1(1,5 and 10μM)groups.The neurons were with Rg1(1,5 and 10 μmol·L-1) for 6h. H2O2(200 μmol·L-1) was added to the medium and incubate for 18 h. The Dihydroethidium (DHE) staining was performed for ROS production assessment. The LDH release and Hoechst 33258 were performed to examine the neuronal damage and apoptosis. The immunoblot was used to deter-mine the expression of β-Gal,NOX2,p22phox,p47phox,NLRP-1,ASC and Caspase-1 in hippocampal neurons.The ELISA was performed to detect the levels of IL-1β and IL-18 released in the supernatant in hippocampal neurons.RESULTS Rg1(5 and 10 μmol·L-1)significantly reduced the ROS production, attenuated H2O2-induced neuronal damage and apoptosis (P<0.05, P<0.01). The immunoblot results showed that Rg1(5 and 10 μmol·L-1)treatment significantly decreased the expression of β-Gal,NOX2, p22phox,p47phox,NLRP-1,ASC and Caspase-1 in hippocampal neurons(P<0.05,P<0.01).Additionally, Rg1(5 and 10 μmol·L-1)treatment significantly decreased IL-1β and IL-18 release in the supernatant. CONCLUSION The protective effect of Rg1 in H2O2-induced hippocampal neurons aging may be due to inhibit NOX2-NLRP1 activation.

Enhancement of Allergen-induced Airway Inflammation by NOX2 Deficiency

BACKGROUND: NADPH oxidase (NOX) modulates cell proliferation, differentiation and immune response through generation of reactive oxygen species. Particularly, NOX2 is recently reported to be important for regulating Treg cell differentiation of CD4+ T cells. METHODS: We employed ovalbumin-induced airway inflammation in wild-type and NOX2-deficient mice and analyzed tissue histopathology and cytokine profiles. RESULTS: We investigated whether NOX2-deficiency affects T cell-mediated airway inflammation. Ovalbumin injection which activates T cell-mediated allergic response increased airway inflammation in wild-type mice, as evidenced by increased immune cell infiltration, allergic cytokine expression, and goblet cell hyperplasia in the lung. Interestingly, NOX2 knockout (KO) mice were more susceptible to allergen-induced lung inflammation compared to wild-type mice. Immune cells including neutrophils, lymphocytes, macrophages, and eosinophils were drastically infiltrated into the lung of NOX2 KO mice and mucus secretion was substantially increased in deficiency of NOX2. Furthermore, inflammatory allergic cytokines and eotaxin were significantly elevated in NOX2 KO mice, in accordance with enhanced generation of inflammatory cytokines interleukin-17 and interferon-gamma by CD4+ T cells. CONCLUSION: These results indicate that NOX2 deficiency favorably produces inflammatory cytokines by T cells and thus increases the susceptibility to severe airway inflammation.