Salvianolic acid A displays cardioprotective effects in in vitro models of heart hypoxia/reoxygenation injury

Oxidative stress induced by overproduction of reactive oxygen species (ROS) plays an important role in hypoxia/reoxygenation (H/R) injury. In the present study, effects of salvianolic acid A (1) on heart H/R injury through its antioxidant activity were examined, using a molecule-based ROS scavenging system and cardiomyocyte model of H/R injury, as well as isolated rat heart model. As a result, 1 showed a potent antioxidant activity, scavenging all of the tested ROS and DPPH (2,2-diphenyl-1-picrylhydrazyl). The antioxidant effect of 1 was also observed in cardiomyocytes exposed to H/R. Compound 1 remarkably decreased dihydroethidium and dichlorofluorescein fluorescence and increased cell viability and mitochondrial membrane potential, ΔΨ(m), when compared to the H/R group. In isolated rat hearts exposed to H/R, 1 markedly increased the coronary flow, the peak of pressure development and the valley of pressure development, and significantly reduced the left ventricular end diastolic pressure when compared to the H/R group. These results suggested that 1 had significant protective effects against H/R-induced myocardial injury through its antioxidant activity.     

Antioxidant activity and protective effects of cocoa and kola nut mistletoe (Globimetula cupulata) against ischemia/reperfusion injury in Langendorff-perfused rat hearts

Protection against cardiomyocyte damage following ischemia/reperfusion (I/R) injury is highly desirable in patients with ischemic heart disease. Hydromethanol extracts of Globimetula cupulata (mistletoe) growing on cocoa (CGCE) and kola nut (KGCE) trees were assessed for antioxidant content and cardioprotective potential against I/R. Graded concentrations (1–50 μg/mL) of CGCE or KGCE were tested on Langendorff-perfused rat hearts to evaluate the effects on the flow rate, heart rate, and force of cardiac contraction, while another set of hearts were subjected to biochemical analyses. Both extracts showed good antioxidant content and activity, but KGCE (EC₅₀: 24.8±1.8 μg/mL) showed higher hydroxyl radical scavenging activity than CGCE (70.2±4.5 μg/mL). Both extracts at 3 μg/mL reversed (p < 0.001) membrane peroxidation and the significant decrease in nitrite level, coronary flow rate, and superoxide dismutase and catalase activity caused by the I/R cycle. It is concluded that G. cupulata protects against ischemia–reperfusion injury in rat hearts via augmenting endogenous antioxidants and significant restoration of altered hemodynamic parameters.     

The protective effect of picroside II against hypoxia/reoxygenation injury in neonatal rat cardiomyocytes

Context: Picroside II, an iridoid glucoside found in the root of Picrorhiza scrophulariiflora Pennell (Scrophulariaceae), has been demonstrated to possess potent antioxidant activity. However, whether picroside II has a protective effect against hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury is poorly understood.

Objective: To explore the cardioprotective role of picroside II against oxidative stress induced by H/R injury in neonatal rat cardiacmyocytes.

Materials and methods: The viability and cellular damage of cardiomyocytes were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolim bromide (MTT) and lactate dehydrogenase (LDH) assays, respectively. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), the levels of reduced (GSH) and oxidized glutathione (GSSG), and the contents of malondialdehyde (MDA) were determined by a colorimetric method. The levels of intracellular reactive oxygen species (ROS) and calcium were evaluated by flow cytometric analysis.

Results: We analyzed the effective half-maximal concentration for protection from the dose-response curves and obtained the concentration of 50 µg/mL as EC₅₀. Pretreated cardiomyocytes with picroside II (50–200 µg/mL), prior to H/R exposure, inhibited LDH activity in culture media and increased cell viability in a dose-dependent manner. This protective effect was accompanied by significantly increasing reduced GSH contents and the activities of SOD and GSH-Px and attenuating MDA and GSSG contents in response to H/R injury. Furthermore, treatment with picroside II also inhibited ROS production and calcium accumulation in cardiomyocytes.

Discussion and conclusion: The present study demonstrates that picroside II protects cardiomyocytes against oxidative-stress injury induced by H/R through reduction of ROS production and calcium accumulation and enhancement of the activity of antioxidant defense.     

The effects of tramadol on hepatic ischemia/reperfusion injury in rats

Objectives:Tramadol is a centrally acting synthetic analgesic. It has a cardioprotective effect against myocardial ischemia-reperfusion (I/R) injury in isolated rat heart. We hypothesized that tramadol may exert a similar protective effect on hepatic I/R injury. Hence, the current investigation was designed to study the possible protective effects of tramadol on experimentally-induced hepatic I/R injury in rats.Results:Tramadol attenuated hepatic injury induced by I/R as evidenced by the reduction of transaminases, structural changes, and apoptotic cell death. It decreased the level of inflammatory markers such as tumor necrosis factor-alpha (TNF-α), TNF-α/interleukin-10 (IL-10) ratio, and nuclear factor-κB gene expression. It also increased the anti-inflammatory cytokine, IL-10 levels in hepatic tissues. Furthermore, it reduced oxidative stress parameters except manganese superoxide dismutase activity.Conclusion:The results suggest that tramadol has hepatoprotective effects against hepatic I/R injury via anti-inflammatory, antiapoptotic, and antioxidant effects.KEY WORDS: Angioedema, anti-histamines, chronic urticaria, histaglobulin, urticaria activity score     

Cardioprotective effect of KR-33889, a novel PARP inhibitor,against oxidative stress-induced apoptosis in H9c2 cells and isolated rat hearts

Oxidative stress plays a critical role in cardiac injury during ischemia/reperfusion (I/R). Despite a potent cardioprotective activity of KR-33889, a novel poly (ADP-ribose) polymerase inhibitor, its underlying mechanism remains unresolved. This study was designed to investigate the protective effects of KR-33889 against oxidative stress-induced apoptosis in rat cardiomyocytes H9c2 cells and isolated rat hearts. H₂O₂ caused severe injury to H9c2 cells, mainly due to apoptosis, as revealed by TUNEL assay. However, KR-33889 pretreatment significantly attenuated H₂O₂-induced apoptosis of H9c2 cells, which was accompanied by decrease in expression of both cleaved caspase-3 and Bax and increase in Bcl-2 expression and the ratio of Bcl-2/Bax. KR-33889 also significantly enhanced the expression of anti-oxidant enzymes including heme oxygenase-1, Cu/Zn-superoxide dismutase (SOD), Mn-SOD, and catalase, thereby inhibiting production of intracellular ROS. Furthermore, KR-33889 reversed H₂O₂-induced decrease in phosphorylation of Akt, GSK-3β, ERK1/2, p38 MAPK, and SAPK/JNK during most H₂O₂ exposure time. In globally ischemic rat hearts, KR-33889 inhibited both I/R-induced decrease in cardiac contractility and apoptosis by increasing Bcl-2, decreasing both cleaved caspase-3 and Bax expression, and enhancing expression of anti-oxidant enzymes. Taken together, these results suggest that KR-33889 may have therapeutic potential to prevent I/R-induced heart injury in ischemic heart diseases mainly by reducing oxidative stress-mediated myocardial apoptosis.     

Protective effect of T3 peptide,an active fragment of tumstatin,against ischemia/reperfusion injury in rat heart

Ischemia/reperfusion (I/R)-induced oxidative stress is a serious clinical problem in the reperfusion therapy for ischemic diseases. Tumstatin is an endogenous bioactive peptide cleaved from type IV collagen α3 chain. We previously reported that T3 peptide, an active subfragment of tumstatin, exerts cytoprotective effects on H₂O₂-induced apoptosis through the inhibition of intracellular reactive oxygen species (ROS) production in H9c2 cardiomyoblasts. In this study, we investigated whether T3 peptide has cardioprotective effects against I/R injury by using in vitro and ex vivo experimental models. H9c2 cardiomyoblasts were stimulated with oxygen and glucose deprivation (OGD) for 12 h followed by reoxygenation for 1–8 h (OGD/R; in vitro model). The cells were treated with T3 peptide (30–1000 ng/ml) during OGD. Ten minutes after the pre-perfusion of T3 peptide (300 ng/ml), Langendorff perfused rat hearts were exposed to ischemia for 30 min followed by reperfusion for 1 h (ex vivo model). T3 peptide inhibited OGD/R-induced apoptosis through the inhibition of mitochondrial ROS production and dysfunction in H9c2 cardiomyoblasts. T3 peptide also prevented I/R-induced cardiac dysfunction, arrhythmia and myocardial infarction in the perfused rat heart. In conclusion, we for the first time demonstrated that T3 peptide exerts cardioprotective effects against I/R injury.     

“新冠三方”的体外抗氧化作用比较

目的 平行比较“新冠三方”(清肺排毒汤、化湿败毒方和宣肺败毒方,以下简称“三方”)的体外抗氧化作用。方法在非细胞体系中,采用FRAP法考察三方的总抗氧化能力;通过DPPH法考察三方对DPPH自由基的清除作用;采用NBT还原法考察三方对超氧阴离子的清除作用;通过基于终产物丙二醛的荧光测定法考察三方对羟自由基的清除作用;用FeSO4体外诱导大鼠肝匀浆MDA法考察三方对抗脂质过氧化的作用。依据以上5个抗氧化指标,平行比较三方提取物在非细胞体系的抗氧化能力。进一步地,在脂多糖活化的RAW264.7细胞模型上,分别使用L-012探针和MitoSOX线粒体超氧化物红色荧光探针检测胞质与线粒体活性氧(reactive oxygen species,ROS)的生成情况;通过光泽精探针检测胞质NADPH氧化酶活性,以平行比较三方提取物在细胞体系的抗氧化能力。结果 在非细胞体系中,三方均能剂量依赖地清除DPPH自由基、超氧阴离子和羟自由基,并且能有效对抗脂质过氧化的发生。在等提取物浓度下,三方对DPPH自由基与超氧阴离子的清除作用相当,总抗氧化能力相当,而化湿败毒方在清除羟自由基和对抗脂质过氧化方面表现更...     

Angiotensin AT1 receptor blockers suppress ischemia/reperfusion-induced gastric injury in rats

Ischemia/reperfusion (I/R) damages gastric mucosa via reactive oxygen species (ROS) activity. ROS was reportedly produced through angiotensin II stimulation in tissues such as kidney, heart and brain. To determine whether AT1 receptor plays a role in gastric mucosal damage, we examined the effect of AT1 receptor blocker (ARB; losartan, candesartan, valsartan) on I/R-induced gastric injury in rats. I/R produced microscopic gastric hemorrhagic injury, and increased gastric microvascular permeability and H₂O₂ production in rats. The mucosal lesions induced by I/R were attenuated by pretreatment of each ARB. The increase in microvascular permeability was suppressed by losartan pretreatment. Additionally, I/R-caused H₂O₂ activation was not observed by pretreatment of losartan, candesartan and valsartan. These results suggest that angiotensin II stimulation via AT1 receptor and following ROS production in the stomach contribute to the pathogenesis of the gastric I/R injury. Received 31 July 2006; revised 29 August 2006; accepted 21 August 2006     

Ligularia fischeri extract attenuates liver damage induced by chronic alcohol intake

Context Ligularia fischeri (Ledebour) Turcz. (Compositae) has been used as a leafy vegetable and in traditional medicine to treat hepatic disorder in East Asia.

Objective The present study explores the antioxidant activity of LF aqueous extract on EtOH-induced oxidative stress accompanied by hepatotoxicity both in vitro and in vivo.

Materials and methods In vitro study using the mouse liver NCTC-1469 cell line was conducted to estimate the cytotoxicity as well as the inhibitory effect of LF extract against alcohol-treated cell damage. In vivo study used an alcohol-fed Wister rat model orally administered EtOH (3.95?g/kg of body weight/d) with or without LF extract (100 or 200?mg/kg body weight) for 6 weeks. Serum and liver tissue were collected to evaluate hepatic injury and antioxidant-related enzyme activity.

Results The EC₅₀ value for the DPPH radical scavenging capacity of LF extract was 451.5?μg/mL, whereas the IC₅₀ value of LF extract in terms of EtOH-induced reactive oxygen species (ROS) generation was 98.3?μg/mL without cell cytotoxicity. LF extract (200?mg/kg body weight) significantly reduced the triglyceride content of serum (33%) as well as hepatic lipid peroxidation (36%), whereas SOD activity was elevated three-fold. LF extract suppressed expression of CYP2E1 and TNF-α, and attenuated alcohol-induced abnormal morphological changes.

Discussion and conclusion LF extract attenuated liver damage induced by alcoholic oxidative stress through inhibition of ROS generation, down-regulation of CYP2E1, and activation of hepatic antioxidative enzymes. Homeostasis of the antioxidative defence system in the liver by LF extract mitigated hepatic disorder following chronic alcohol intake.     

Maculosin,a non-toxic antioxidant compound isolated from Streptomyces sp. KTM18

ContextStreptomyces species are prolific sources of bioactive secondary metabolites known especially for their antimicrobial and anticancer activities.ObjectiveThis study sought to isolate and characterize antioxidant molecules biosynthesized by Streptomyces sp. KTM18. The antioxidant potential of an isolated compound and its toxicity were accessed.Materials and methodsThe compound was purified using bioassay-guided chromatography techniques. Nuclear magnetic resonance (NMR) experiments were carried out for structure elucidation. The antioxidant potential of the isolated compound was determined using DPPH free radical scavenging assay. The toxicity of the isolated compound was measured using a brine shrimp lethality (BSL) assay.ResultsEthyl acetate extract of Streptomyces sp. KTM18 showed more than 90% inhibition of DPPH free radical at 50 µg/mL of the test concentration. These data were the strongest among 13 Streptomyces isolates (KTM12–KTM24). The active molecule was isolated and characterized as maculosin (molecular formula, C₁₄H₁₆N₂O₃ as determined by the [M + H]⁺ peak at 261.1259). The DPPH free radical scavenging activity of pure maculosin was higher (IC₅₀, 2.16 ± 0.05 µg/mL) than that of commercial butylated hydroxyanisole (BHA) (IC₅₀, 4.8 ± 0.05 µg/mL). No toxicity was observed for maculosin (LD₅₀, <128 µg/mL) in brine shrimp lethality assay (BSLA) up to the compound’s antioxidant activity (IC₅₀) concentration range. The commercial standard, berberine chloride, showed toxicity in BSLA with an LD₅₀ value of 8.63 ± 0.15 µg/mL.ConclusionsMaculosin may be a leading drug candidate in various cosmetic and therapeutic applications owing to its strong antioxidant and non-toxic properties.     

New phenylpropanoid esters of sucrose from <Emphasis Type="Italic">Polygonum hydropiper</Emphasis> and their antioxidant activity

By various chromatographic methods, two new phenylpropanoid esters of sucrose named hidropiperosides A (1) and B (2), and three known compounds as vanicosides A (3), B (4), and E (5) were isolated from the methanolic extract of the whole plant of Polygonum hydropiper L. (Polygonaceae). Their structures were elucidated by extensive spectroscopic methods including 1D-and 2D-NMR experiments, as well as ESI-MS analysis. All the isolated compounds were tested for their antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay system. Among them, compounds 2 and 3 showed significant antioxidant activity with their SC₅₀ values of 23.4 and 26.7 μg/mL, respectively.     

Phenylpropanoids from the leaves of Acanthopanax koreanum and their antioxidant activity

By various chromatographic methods, one new phenylpropanoid, acanthopanic acid (1), and three known compounds, 1,2-O-dicaffeoylcyclopenta-3-ol (2), (4S)-α-terpineol 8-O-β-D-glucopyranoside (3), and rutin (4), were isolated from the methanol extract of the Acanthopanax koreanum leaves. Their structures were elucidated on the basis of spectroscopic analyses, and their antioxidant activities were evaluated by the intracellular reactive oxygen species (ROS) radical scavenging 2′,7′-dichlorofluorescein diacetate assay. Among them, compounds 1, 2, and 4 showed significant scavenging capacity with IC₅₀ values of 3.8, 2.6, and 2.9 μM, respectively, and compound 3 showed weak scavenging capacity with the inhibition rate of 37% at 40 μM.     

nNOS抑制剂亚胺基烯丁基-L-鸟氨酸对心肌缺血再灌注损伤的影响及机制

目的 探讨nNOS选择性抑制剂亚胺基烯丁基-L-鸟氨酸（L-VNIO）对心肌缺血再灌注（I/R）损伤的影响及机制。方法 构建SD大鼠离体心脏I/R模型和H9c2细胞缺氧/复氧（H/R）模型；nNOS抑制剂L-VNIO（10 μmol·L^-1）持续给药整个再灌注或复氧过程。TTC染色测定心肌梗死面积；流式细胞术检测H9c2细胞凋亡率；Fluo-3/AM Ca²⁺荧光探针通过流式细胞仪检测H9c2细胞内Ca²⁺浓度；试剂盒法测定离体心脏灌流液乳酸脱氢酶（LDH）、丙二醛（MDA）水平以及H9c2细胞MDA水平和超氧化物歧化酶（SOD）活性；离体心脏提取肌浆网，试剂盒法检测肌浆网Ca²⁺-ATP酶（SERCA）活性，Western blotting检测肌浆网SERCA蛋白表达；Western blotting检测离体心脏中受磷蛋白（PLB）和兰尼碱受体2（RyR2）蛋白表达水平和磷酸化水平。结果 与I/R或H/R模型组相比，L-VNIO显著降低细胞凋亡率，减少心肌梗死面积，降低LDH、MDA水平，提高SOD活性，差异均有统计学意义（P<0.05）；此外，与I/R或H/R模型组相比，L-VNIO组明显降低细胞内Ca²⁺超载，增高PLB磷酸化水平，降低RyR2磷酸化水平，增强SERCA活性（P<0.05）。结论 nNOS抑制剂L-VNIO可以减轻I/R损伤，机制与调节Ca²⁺转运相关蛋白而降低I/R引起的Ca²⁺超载相关。     

Anti-apoptotic and cytoprotective effect of Enicostemma littorale against oxidative stress in Islets of Langerhans

Context Oxidative stress induces apoptosis within Islets of Langerhans in diabetes mellitus (DM). Enicostemma littorale blume, herb of the Gentianaceae family is used as an anti-diabetic agent across rural India.

Objective This report demonstrates potent anti-apoptotic and cyto-protective activity of Enicostemma littorale MeOH extract (EL MeOH ext.) against 50?μM H₂O₂ in isolated rat Islets.

Materials and methods In this study, the whole plant methanolic extract of EL with doses 0.25–4?mg/mL each for the preincubation duration of 0.5–4?h against 50?μM H₂O₂ were tested for optimum protective dose and time by Trypan blue dye exclusion assay. Islet intracellular reactive oxygen species (ROS) was quantified by DCFDA staining and cell death using PS/PI & FDA/PI staining. Further, comet assay, biochemical assessment of caspase-3 and antioxidant enzyme activities along with immunoblotting of PARP-1, caspase-3, TNF-α activation and p-P38 MapK (stress kinase) induction was performed.

Results The optimized dose of EL MeOH ext. 2?mg/mL for 2?h was used throughout the study, which significantly decreased total Intracellular ROS and cell death. Further, caspase-3 activity, PARP-1 cleavage, p-P38 MapK (stress kinase) activation and TNF-α levels, which had been significantly elevated, were normalized. Antioxidant enzymes like catalase, superoxide dismutase, reduced glutathione and glutathione peroxidase, along with Comet assay, demonstrated that pretreatment with EL MeOH ext. can augment antioxidant enzyme activities and protect from DNA damage.

Discussion and conclusions Significant anti-apoptotic and cyto-protective effects were mediated by EL with Islets of Langerhans subjected to oxidative stress-induced cell death.     

野牡丹提取液的抗氧化活性研究

目的 研究野牡丹提取液的抗氧化活性。方法 采用二苯代苦味肼基自由基（DPPH•）和铁离子还原/抗氧化能力（FRAP）测定法,测定其抗氧化活性,并将其与芦丁和维生素C（Vc）的抗氧化能力进行比较研究。结果 野牡丹提取液具有较强的抗氧化能力,对DPPH自由基有较好的清除率,半数清除浓度（IC₅₀）为23 μg/mL;对Fe³⁺也具有较好的还原能力,0.5 mol/L FeSO₄当量对应野牡丹提取液质量浓度为55 μg/mL。结论 野牡丹的抗氧化能力与芦丁相近,低于Vc。野牡丹的抗氧化活性在一定浓度范围内与黄酮的含量有较好的相关性。     

A new phenanthrene dimer from Dendrobium palpebrae

A new phenanthrene dimer, namely dendropalpebrone (1), was isolated from the whole plant of Dendrobium palpebre, along with nine known compounds (2–10). All of the isolates were evaluated for their hydroxyl radical scavenging effects using a deoxyribose assay. Dendroflorin (10) showed an appreciable activity, and therefore was selected for further studied in RAW264.7 cells. Compound 10 significantly decreased ROS in H₂O₂-stimulated RAW264.7 cells in a dose-dependent manner, and improved activity of SOD, GPx, and CAT enzymes.     

The protective effect of picroside II against hypoxia/reoxygenation injury in neonatal rat cardiomyocytes

Context: Picroside II, an iridoid glucoside found in the root of Picrorhiza scrophulariiflora Pennell (Scrophulariaceae), has been demonstrated to possess potent antioxidant activity. However, whether picroside II has a protective effect against hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury is poorly understood. Objective: To explore the cardioprotective role of picroside II against oxidative stress induced by H/R injury in neonatal rat cardiacmyocytes. Materials and methods: The viability and cellular damage of cardiomyocytes were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolim bromide (MTT) and lactate dehydrogenase (LDH) assays, respectively. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), the levels of reduced (GSH) and oxidized glutathione (GSSG), and the contents of malondialdehyde (MDA) were determined by a colorimetric method. The levels of intracellular reactive oxygen species (ROS) and calcium were evaluated by flow cytometric analysis. Results: We analyzed the effective half-maximal concentration for protection from the dose-response curves and obtained the concentration of 50 μg/mL as EC(50). Pretreated cardiomyocytes with picroside II (50-200 μg/mL), prior to H/R exposure, inhibited LDH activity in culture media and increased cell viability in a dose-dependent manner. This protective effect was accompanied by significantly increasing reduced GSH contents and the activities of SOD and GSH-Px and attenuating MDA and GSSG contents in response to H/R injury. Furthermore, treatment with picroside II also inhibited ROS production and calcium accumulation in cardiomyocytes. Discussion and conclusion: The present study demonstrates that picroside II protects cardiomyocytes against oxidative-stress injury induced by H/R through reduction of ROS production and calcium accumulation and enhancement of the activity of antioxidant defense.     

Hepatoprotective properties of red betel (Piper crocatum Ruiz and Pav) leaves extract towards H2O2-induced HepG2 cells via anti-inflammatory,antinecrotic, antioxidant potency

BackgroundProlonged exposure of free radicals, or known as reactive oxygen species (ROS), in hepatic cells may cause oxidative stress. Without proper treatment, it can induce liver injury and fatal hepatic disease, including cirrhosis. Red betel (Piper crocatum Ruiz and Pav) is one of Indonesia’s medicinal plants that has been known to exhibit antioxidant, anti-inflammatory activities. This study aims to determine hepatoprotective effect of red betel leaves extract (RBLE) towards liver injury.MethodHydrogen peroxide-induced HepG2 cells were used as liver injury model·H₂O₂-induced HepG2 cells were treated with 25 µg/mL and 100 µg/mL RBLE. Several parameters were observed, including TNF-α level through ELISA; necrotic, apoptotic, dead, live cells; and ROS level through flow cytometry analysis; and GPX gene expression through qPCR.ResultThe study showed that treatment with RBLE were able to decrease TNF-α level; necrotic and death cells percentage; as well as ROS level. On the other hand, it were able to increase apoptotic and live cells percentage; as well as GPX gene expression. Low concentration (25 µg/mL) of RBLE treatment exhibited stronger anti-inflammatory activity as it was resulted in the lower TNF-α level and were able to switched hepatic cell death pathway from necrosis to apoptosis as shown by the shifted of apoptotic cells and necrotic cells percentage. This lead to lower death cells and ultimately improve live cells percentage. Meanwhile high concentration of RBLE (100 µg/mL) exhibited stronger antioxidant properties as indicated by lower ROS level and higher GPX gene expression.ConclusionOverall, this study was able to demonstrate hepatoprotective effect of RBLE towards liver injury model through its anti-inflammatory and antioxidant activities.     

Didymin ameliorates hepatic injury through inhibition of MAPK and NF-κB pathways by up-regulating RKIP expression

A flavone was isolated from Origanum vulgare and identified as didymin (O. vulgare didymin, OVD). The protective effect and mechanism of OVD on acute liver injury was then assessed in vivo and in vitro. Our results showed that OVD significantly alleviated CCl₄-induced liver injury in mice and markedly decreased serum ALT and AST activities. OVD treatment significantly reduced CYP2E1 activity, lipid peroxidation level, ROS generation, NO production and pro-inflammatory cytokines (such as TNF-α, IL-6 and IL-1β) in liver tissues and RAW 264.7 cells, but enhanced the hepatic antioxidative enzymes activities. Further study showed that OVD significantly inhibited the NF-κB and MAPK pathways. Interestingly, OVD notably enhanced Raf kinase inhibitor protein (RKIP) expression, and the effects of OVD on histological changes, oxidative stress and inflammation was largely abolished by the RKIP specific inhibitor locostatin. Our findings indicate that OVD can ameliorate CCl₄-induced liver injury, which may be ascribed to its radical scavenging action, antioxidant activity, and modulation of MAPK and NF-κB signaling pathways.