scholarly journals Maggot Extracts Alleviate Inflammation and Oxidative Stress in Acute Experimental Colitis via the Activation of Nrf2

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Rong Wang ◽  
Yongzheng Luo ◽  
Yadong Lu ◽  
Daojuan Wang ◽  
Tingyu Wang ◽  
...  

Ulcerative colitis (UC) is a common chronic remitting disease driven through altered immune responses with production of inflammatory cytokines. Oxidant/antioxidant balance is also suggested to be an important factor for the recurrence and progression of UC. Maggots are known as a traditional Chinese medicine also known as “wu gu chong.” NF-E2-related factor-2 (Nrf2) transcription factor regulates the oxidative stress response and also represses inflammation. The aim of this study was to investigate the effects of maggot extracts on the amelioration of inflammation and oxidative stress in a mouse model of dextran sulfate sodium- (DSS-) induced colitis and evaluate if the maggot extracts could repress inflammation and oxidative stress using RAW 264.7 macrophages stimulated by lipopolysaccharide (LPS). In the present study, we found that the maggot extracts significantly prevented the loss of body weight and shortening of colon length in UC induced by DSS. Furthermore, DSS-induced expression of proinflammatory cytokines at both mRNA and protein levels in the colon was also attenuated by the maggot extracts. In addition, the maggot extracts could significantly suppress the expression of interleukin- (IL-) 1β, IL-6, TNF-α, NFκB p65, p-IκB, p22-phox, and gp91-phox in LPS-stimulated RAW 264.7 cells and colonic tissues. The maggot extracts increased the level of Nrf2 and prevented the degradation of Nrf2 through downregulating the expression of Keap1, which resulted in augmented levels of HO-1, SOD, and GSH-Px and reduced levels of MPO and MDA. However, after administering an Nrf2 inhibitor (ML385) to block the Nrf2/HO-1 pathway, we failed to observe the protective effects of the maggot extracts in mice with colitis and RAW 264.7 cells. Taken together, our data for the first time confirmed that the maggot extracts ameliorated inflammation and oxidative stress in experimental colitis via modulation of the Nrf2/HO-1 pathway. This study sheds light on the possible development of an effective therapeutic strategy for inflammatory bowel diseases.

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jinfang Deng ◽  
Zhenpeng He ◽  
Xiuru Li ◽  
Wei Chen ◽  
Ziwen Yu ◽  
...  

Background. Huangkui capsule (HKC) comprises the total flavonoid extract of flowers of Abelmoschus manihot (L.) Medicus. This study aimed to explore the effects of HKC on lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in mice and LPS-stimulated RAW 264.7 cells. Methods. Enzyme-linked immunosorbent assay, histopathology, spectrophotometry, and quantitative real-time polymerase chain reaction were used for the assessments. Statistical analysis was performed using a one-way analysis of variance. Results. LPS significantly increased lung inflammation, neutrophil infiltration, and oxidative stress and downregulated lung miR-451 expression. Treatment with HKC dramatically attenuated the lung wet/dry weight ratio, reduced the total cell count in the bronchoalveolar lavage fluid (BALF), and inhibited myeloperoxidase activity in the lung tissues 24 h after LPS challenge. Histopathological analysis demonstrated that HKC attenuated LPS-induced tissue oedema and neutrophil infiltration in the lung tissues. Additionally, the concentrations of tumour necrosis factor- (TNF-) α and interleukin- (IL-) 6 in BALF and IL-6 in the plasma reduced after HKC administration. Moreover, HKC could enhance glutathione peroxidase and catalase activities and upregulate the expression of miR-451 in the lung tissues. In vitro experiments revealed that HKC inhibited the production of nitric oxide, TNF-α, and IL-6 in LPS-induced RAW 264.7 cells and mouse primary peritoneal macrophages. Additionally, HKC downregulated LPS-induced transcription of TNF-α and IL-6 in RAW 264.7 cells. Conclusions. These findings suggest that HKC has anti-inflammatory and antioxidative effects that may protect mice against LPS-induced ALI and macrophage activation.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Dong-Woo Lim ◽  
Hee-Jin Choi ◽  
Sun-Dong Park ◽  
Hyuck Kim ◽  
Ga-Ram Yu ◽  
...  

Despite its deleterious effects on living cells, oxidative stress plays essential roles in normal physiological processes and provides signaling molecules for cell growth, differentiation, and inflammation. Macrophages are equipped with antioxidant mechanisms to cope with intracellular ROS produced during immune response, and Nrf2 (NF-E2-related factor 2)/HO-1 (heme oxygenase-1) pathway is an attractive target due to its protective effect against ROS-induced cell damage in inflamed macrophages. We investigated the effects of ethanol extract of A. villosum (AVEE) on lipopolysaccharide- (LPS-) stimulated inflammatory responses generated via the Nrf2/HO-1 signaling pathway in murine peritoneal macrophages and RAW 264.7 cells. AVEE was found to suppress the NF-κB signaling pathway, thus, to reduce proinflammatory cytokine, nitric oxide, and prostaglandin levels in peritoneal macrophages and Raw 264.7 cells treated with LPS, and to enhance HO-1 expression by activating Nrf2 signaling. Furthermore, these anti-inflammatory effects of AVEE were diminished when cells were pretreated with SnPP (a HO-1 inhibitor). HPLC analysis revealed AVEE contained quercetin, a possible activator of the Nrf2/HO-1 pathway. These results show A. villosum ethanol extract exerts anti-inflammatory effects by activating the Nrf2/HO-1 pathway in LPS-stimulated macrophages.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yu-Ting Wu ◽  
Ling-Peng Xie ◽  
Yue Hua ◽  
Hong-Lin Xu ◽  
Guang-Hong Chen ◽  
...  

Cardiovascular disease, a disease caused by many pathogenic factors, is one of the most common causes of death worldwide, and oxidative stress plays a major role in its pathophysiology. Tanshinone I (Tan I), a natural compound with cardiovascular protective effects, is one of the main active compounds extracted from Salvia miltiorrhiza. Here, we investigated whether Tan I could attenuate oxidative stress and oxidative stress–induced cardiomyocyte apoptosis through Nrf2/MAPK signaling in vivo and in vitro. We found that Tan I treatment protected cardiomyocytes against oxidative stress and oxidative stress–induced apoptosis, based on the detection of relevant oxidation indexes such as reactive oxygen species, superoxide dismutase, malondialdehyde, and apoptosis, including cell viability and apoptosis-related protein expression. We further examined the mechanisms underlying these effects, determining that Tan I activated nuclear factor erythroid 2 (NFE2)–related factor 2 (Nrf2) transcription into the nucleus and dose-dependently promoted the expression of Nrf2, while inhibiting MAPK signaling activation, including P38 MAPK, SAPK/JNK, and ERK1/2. Nrf2 inhibitors in H9C2 cells and Nrf2 knockout mice demonstrated aggravated oxidative stress and oxidative stress–induced cardiomyocyte injury; Tan I treatment suppressed these effects in H9C2 cells; however, its protective effect was inhibited in Nrf2 knockout mice. Additionally, the analysis of surface plasmon resonance demonstrated that Tan I could directly target Nrf2 and act as a potential Nrf2 agonist. Collectively, these data strongly indicated that Tan I might inhibit oxidative stress and oxidative stress–induced cardiomyocyte injury through modulation of Nrf2 signaling, thus supporting the potential therapeutic application of Tan I for oxidative stress–induced CVDs.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Kaixiang Xu ◽  
Xiaohong Zang ◽  
Mian Peng ◽  
Qian Zhao ◽  
Binbin Lin

Background. Magnesium lithospermate B (MLB) was shown to suppress oxidative stress and reduce hypertension, but the role of MLB in pregnancy-induced hypertension (PIH) remains unknown. The objective of this study was to demonstrate the effects of MLB on rats with PIH. Methods. A total of 40 pregnant SD rats were selected, and 30 rats were orally given NG-nitro-L-arginine methyl ester (L-NAME, 60 mg/kg/day) to establish PIH rat models. Rats were equally divided into four groups: control, PIH, 5 mg/kg MLB, and 10 mg/kg MLB. MLB was consecutively administered into PIH rats for one week. The effects of MLB on mean arterial blood pressure (MAP), urine protein level, inflammation, and oxidative stress together with angiogenesis were analyzed. Results. MLB prevented the elevation in MAP and urine protein levels induced by L-NAME. The activities of inflammatory cytokines were highly increased in serum and placental tissues of PIH rats, while cotreatment with MLB partially reversed the activities of these cytokines. MLB also recovered the expression of reactive oxygen species (ROS) in plasma of PIH rats together with levels of oxidative stress and antioxidant capacity in the placenta of PIH rats. The decreased expressions of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS), and NO observed in PIH rats were increased by MLB. In addition, 10 mg/kg MLB exhibited higher protective effects as compared to lower doses of 5 mg/kg. Conclusion. This study demonstrated that pretreatment with MLB decreased MAP, inflammation, and oxidative stress in rats with gestational hypertension.


Antioxidants ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 82 ◽  
Author(s):  
Da Kwon ◽  
Hee-Jae Cha ◽  
Hyesook Lee ◽  
Su-Hyun Hong ◽  
Cheol Park ◽  
...  

Reactive oxygen species (ROS), products of oxidative stress, contribute to the initiation and progression of the pathogenesis of various diseases. Glutathione is a major antioxidant that can help prevent the process through the removal of ROS. The aim of this study was to evaluate the protective effect of glutathione on ROS-mediated DNA damage and apoptosis caused by hydrogen peroxide, H2O2, in RAW 264.7 macrophages and to investigate the role of the nuclear factor erythroid 2-related factor-2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway. The results showed that the decrease in the survival rate of RAW 264.7 cells treated with H2O2 was due to the induction of DNA damage and apoptosis accompanied by the increased production of ROS. However, H2O2-induced cytotoxicity and ROS generation were significantly reversed by glutathione. In addition, the H2O2-induced loss of mitochondrial membrane potential was related to a decrease in adenosine triphosphate (ATP) levels, and these changes were also significantly attenuated in the presence of glutathione. These protective actions were accompanied by a increase in the expression rate of B-cell lymphoma-2 (Bcl-2)/Bcl-2-associated X protein (Bax) and poly(ADP-ribose) polymerase cleavage by the inactivation of caspase-3. Moreover, glutathione-mediated cytoprotective properties were associated with an increased activation of Nrf2 and expression of HO-1; however, the inhibition of the HO-1 function using an HO-1 specific inhibitor, zinc protoporphyrin IX, significantly weakened the cytoprotective effects of glutathione. Collectively, the results demonstrate that the exogenous administration of glutathione is able to protect RAW 264.7 cells against oxidative stress-induced mitochondria-mediated apoptosis along with the activity of the Nrf2/HO-1 signaling pathway.


Antioxidants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 465 ◽  
Author(s):  
Victor Udo Nna ◽  
Ainul Bahiyah Abu Bakar ◽  
Azlina Ahmad ◽  
Chinedum Ogbonnaya Eleazu ◽  
Mahaneem Mohamed

Oxidative stress, inflammation and apoptosis are major complications that trigger organ failure in diabetes mellitus (DM), and are proven to adversely affect the male reproductive system. Clinical and experimental studies have demonstrated the promising protective effects of propolis in DM and its associated systemic effects. Herein, we investigated the effect of Malaysian propolis (MP) on testicular oxidative stress, inflammation and apoptosis in diabetic rats. Further, the possibility of a complementary effect of MP with the anti-hyperglycaemic agent, metformin (Met), was studied with the idea of recommending its use in the event that Met alone is unable to contain the negative effects of DM on the male reproductive system in mind. Male Sprague-Dawley rats were either gavaged distilled water (normoglycaemic control and diabetic control groups), MP (diabetic rats on MP), Met (diabetic rats on Met) or MP+Met (diabetic rats on MP+Met), for 4 weeks. MP decreased oxidative stress by up-regulating (p < 0.05) testicular mRNA levels of nuclear factor erythroid 2-related factor 2, superoxide dismutase, catalase and glutathione peroxidase; increasing (p < 0.05) the activities of antioxidant enzymes; and decreasing (p < 0.05) lipid peroxidation in the testes and epididymis of diabetic rats. Further, MP down-regulated (p < 0.05) testicular mRNA and protein levels of pro-inflammatory mediators (nuclear factor kappa B, inducible nitric oxide synthase, tumour necrosis factor-α and interleukin (IL)-1β), decreased (p < 0.05) the nitric oxide level, and increased (p < 0.05) IL-10 mRNA and protein levels. MP also down-regulated (p < 0.05) Bax/Bcl-2, p53, casapase-8, caspase-9 and caspase-3 genes, and increased (p < 0.05) testicular germ cell proliferation. MP’s effects were comparable to Met. However, the best results were achieved following co-administration of MP and Met. Therefore, we concluded that administration of the MP+Met combination better attenuates testicular oxidative stress, inflammation and apoptosis in DM, relative to MP or Met monotherapy, and may improve the fertility of males with DM.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 116-116
Author(s):  
Mi-Bo Kim ◽  
Hyunju Kang ◽  
Ji-Young Lee

Abstract Objectives Anti-inflammatory and antioxidant effects of fucoxanthin (FCX), a carotenoid present in edible brown seaweeds, have been suggested. However, the underlying mechanisms have not been fully understood. The objectives of this study were to determine whether FCX can inhibit lipopolysaccharide (LPS)-induced inflammation and oxidative stress and to elucidate the underlying mechanisms in macrophages. Methods Cytotoxicity of FCX (0–15 μM) was measured in RAW 264.7 macrophage. The effects of the FCX on LPS-induced inflammatory cytokine and antioxidant gene expression were determined in RAW 264.7 macrophages by quantitative realtime PCR, Western blot, and enzyme-linked immunosorbent assays. Cellular reactive oxygen species (ROS) accumulation was measured in LPS-induced RAW 264.7 macrophage. The antioxidant capacity was also determined by 2,2′-azinobis (3-ethylbenzothiazoline 6-sulfonate) (ABTS) radical scavenging activity expressed by trolox equivalent antioxidant capacity (TEAC). Also, a potential role of phosphatidylinositol 3-kinase (PI3K)/nuclear factor E2-related factor 2 (NRF2) axis, a crucial pathway in endogenous antioxidant defense, in the FCX effects was evaluated. Results Cells treated with 5 μM FCX were 90%&lt;viable. LPS significantly increased mRNA levels of interleukin (Il)-6, Il-1β, and tumor necrosis factor α (Tnf) as well as TNFα secretion, which were significantly decreased by FCX. Elevated levels of cellular ROS levels by LPS were abolished by FCX with a concomitant increase in the expression of antioxidant enzymes. ABTS assay demonstrated that FCX had a stronger free radical scavenging property (57.6 TEAC μM/100 μM). Also, FCX significantly increased Nrf2 and heme oxygenase 1 expression compared to LPS control. LPS increased the nuclear translocation of NRF2, which was further increased by FCX. Interestingly, LY294002, an inhibitor of PI3K, noticeably decreased the effect of FCX on NRF2 nuclear translocation. Conclusions FCX exerts anti-inflammatory and antioxidant effects by the activation of NRF2 in LPS-induced macrophages. The increase in NRF2 nuclear translocation is mediated, at least in part, through the PI3K pathway. Funding Sources This study was supported by National Research Foundation of Korea (2019R1A6A3A03032678).


Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1099 ◽  
Author(s):  
Md Badrul Alam ◽  
Arif Ahmed ◽  
Syful Islam ◽  
Hee-Jeong Choi ◽  
Md Abdul Motin ◽  
...  

The antioxidant effects of the ethyl acetate fraction of Dillenia indica bark (DIBEt) and the underlying mechanisms were investigated in tert-butyl hydroperoxide (t-BHP)-stimulated oxidative stress in RAW 264.7 cells. Paper spray ionization-mass spectroscopy with positive-ion mode tentatively revealed 27 secondary metabolites in D. indica bark extract; predominant among them were alkaloids, phenolic acids, and flavonoids. A new triterpenoid (nutriacholic acid) was confirmed in DIBEt for the first time. DIBEt had strong free radical-scavenging capabilities and was also able to reduce t-BHP-induced cellular reactive oxygen species (ROS) generation in RAW 264.7 cells. DIBEt was found to prevent oxidative stress by boosting the levels of heme oxygenase-1 (HO-1) through the up-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2) via the regulation of extracellular signal-regulated kinase (ERK) phosphorylation in RAW 264.7 cells. These results support the potential of DIBEt for defense against oxidative stress-stimulated diseases.


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