A combined extract of Cinnamomi Ramulus, Anemarrhenae Rhizoma and Alpiniae Officinari Rhizoma suppresses production of nitric oxide by inhibiting NF-kappaB activation in RAW 264.7 cells

An herbal mixture prepared with Cinnamomi Ramulus, Anemarrhenae Rhizoma and Alpiniae Officinari Rhizoma (CAA) is used in oriental medicine for treating several ailments. The purpose of this study was to determine the mechanisms by which CAA elicits an antiinflammatory effect on nitric oxide (NO) production in the mouse macrophage cell line RAW 264.7 cells. The results indicated that lipopolysaccharide (LPS)-induced NO production was inhibited by CAA in a dose-dependent manner. Western blotting and RT-PCR analysis demonstrated that CAA decreased LPS-induced inducible nitric oxide synthase (iNOS) protein and gene expression in RAW 264.7 cells. Furthermore, CAA inhibited the LPS-induced DNA binding activity of nuclear factor-kappa B (NF-kappaB) and this effect was mediated through inhibiting the degradation of inhibitory factor-kappaBalpha (IkappaBalpha). Therefore, the results demonstrate that CAA inhibits LPS-induced production of NO and expression of iNOS by blocking NF-kappaB activation. CAA might be a potential therapeutic candidate for treating inflammatory diseases such as arthritis.     

Echinacea increases arginase activity and has anti-inflammatory properties in RAW 264.7 macrophage cells,indicative of alternative macrophage activation

Ethnopharmacological relevance

The genus Echinacea is a popular herbal immunomodulator. Recent reports indicate that Echinacea products inhibit nitric oxide (NO) production in activated macrophages.

Aim of the study

In the present study we determined the inhibitory effects of alcohol extracts and individual fractions of alcohol extracts of Echinacea on NO production, and explored the mechanism underlying the pharmacological anti-inflammatory activity.

Materials and methods

Alcohol extracts of three medicinal Echinacea species, Echinacea angustifolia, Echinacea pallida and Echinacea purpurea, were prepared using Soxhlet apparatus and fractionated using HPLC. NO production by LPS activated RAW 264.7 macrophage cells was measured using a Griess reagent and iNOS detected using immunoblotting. In addition, effects on arginase activity were measured in RAW 264.7 cells stimulated with 8-bromo-cAMP +/− LPS.

Results

Alcohol extracts of all three Echinacea species significantly inhibited NO production by lipopolysaccharide (LPS)-activated the RAW 264.7 macrophage cell line; among them Echinacea pallida was the most active. The Echinacea-mediated decrease in NO production was unlikely due to a direct scavenging of NO because the extracts did not directly inhibit NO released from an NO donor, sodium nitroprusside. An immunoblotting assay demonstrated that the extract of Echinacea pallida inhibited inducible nitric oxide synthase (iNOS) protein expression in LPS-treated macrophages. The enzymes iNOS and arginase metabolize a common substrate, l-arginine, but produce distinct biological effects. While iNOS is involved in inflammatory response and host defense, arginase participates actively in anti-inflammatory activation. Arginase activity of RAW 264.7 cells stimulated with 8-bromo-cAMP was significantly increased by alcohol extracts of all three Echinacea species. The polar fraction containing caffeic acid derivatives enhanced arginase activity, while the lipophilic fraction containing alkamides exhibited a potential of inhibiting NO production and iNOS expression.

Conclusions

These results suggest that the anti-inflammatory activity of Echinacea might be due to multiple active metabolites, which work together to switch macrophage activation from classical activation towards alternative activation.     

Inhibitory effects of butanol fraction of the aqueous extract of Forsythia koreana on the nitric oxide production by murine macrophage-like RAW 264.7 cells

The aim of this study was to investigate the effect of butanol fraction of the aqueous extract of Forsythia koreana fruits on the nitric oxide (NO) production and inducible nitric oxide synthesis (iNOS) gene expression in murine macrophage-like RAW 264.7 cells. Butanol fraction alone affected neither NO production nor iNOS gene expression in macrophage-like RAW 264.7 cells. However, the butanol fraction inhibited NO production and iNOS gene expression in RAW 264. 7 cells stimulated with interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS). These findings suggest that inhibition of NO production by this butanol fraction in RAW 264.7 cells stimulated with IFN-gamma plus LPS was due to the suppression of iNOS gene expression.     

Effects of bee venom on the pro-inflammatory responses in RAW264.7 macrophage cell line

The purpose of this study is to elucidate the molecular mechanism of anti-inflammatory effect of bee venom (BV), which has been used for the treatment of various inflammatory diseases in oriental medicine. With this aim, we examined the effects of BV on the nitric oxide (NO) production by lipopolysaccharide (LPS) or sodium nitroprusside in RAW264.7 macrophages. We further investigated the effects of BV on the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear factor-kappaB (NF-kappaB) and mitogen-activated protein kinase (MAPK) with RT-PCR in LPS-stimulated RAW264.7 cells. BV suppressed the NO production and decreased the levels of iNOS, COX-2, NF-kappaB and MAPK mRNA in a dose-dependent manner. These results suggest that BV has an anti-inflammatory effect by inhibiting iNOS and COX-2 expression, possibly through suppression of NF-kappaB and MAPK expression.     

藏药十八味党参丸提取物对脂多糖诱导的RAW264.7细胞Akt/p38MAPK信号通路及M1/M2极化影响的探究

目的探究藏药十八味党参丸(TEP)的提取物调控脂多糖(LPS)诱导小鼠巨噬细胞RAW 264.7的炎性反应及M1/M2极化分型的探究。方法 Alarmarblue法评价RAW 264.7活力;荧光酶标定量分析细胞活性氧(reactive oxygen species, ROS)水平;Griess法检测上清液中细胞一氧化氮(NO)的分泌情况;流式细胞术检测表面标志物CD206和CCR7蛋白的表达;RT-qPCR法检测细胞白介素(IL)-1β、IL-6、趋化因子2(CCL2)、一氧化氮合酶(iNOS)、精氨酸酶(ARG)-1和肿瘤坏死因子α(TNF-α)基因表达的情况;Western blot法检测TEP调控细胞合成iNOS、蛋白激酶B(Akt)和p38丝裂原活化激酶(p38MAPK)信号通路相关蛋白的表达情况。结果与模型组相比,TEP组一定程度上提高了RAW 264.7的细胞活性,同时抑制了LPS诱导的细胞内ROS水平的升高。经过LPS刺激后,模型组NO表达量显著升高,在24 h后表达量达到最高,而TEP组NO表达显著降低。模型组的CCR7表达升高,CD206表达下降,TEP干预后CCR7表达下降,CD206表达升高,且趋势呈现浓度依赖。与模型组相比,TEP组的IL-1β、IL-6、CCL2、iNOS、ARG和TNF-α基因表达以及iNOS、Akt和p38MAPK蛋白表达水平均显著降低。结论 TEP能够抑制细胞内ROS水平,降低NO分泌和炎性基因的表达水平,抑制细胞的M1表型,促进M2表型,其机制可能与细胞内iNOS、Akt和p38MAPK信号通路蛋白表达被抑制有关。     

芪麝丸体外抗炎的机制

目的:考察芪麝丸体外对小鼠RAW264.7巨噬细胞炎症模型的抗炎机制.方法:干扰素γ(1×104 U·mL-1)和脂多糖(100μg·L-1)协同诱导小鼠RAW264.7巨噬细胞(1×105/mL)24 h造成炎症模型;Griess反应测定细胞上清液中一氧化氮(NO)产量;Western blot检测诱导型一氧化氮合酶(iNOS)、环氧合酶(COX-2)的蛋白表达及丝裂原活化蛋白激酶(MAPK)信号转导通路的活化情况.结果:芪麝丸(250,500,1000 mg·L-1)呈剂量依赖性抑制细胞上清液中NO含量,且无细胞毒性.较模型组,经芪麝丸500,1000 mg·L-1剂量处理后,iNOS蛋白表达从(1.00±0.06)下调至(0.61±0.07)和(0.02±0.15),(P＜0.01),COX-2蛋白表达从(0.56±0.03)下调至(0.42±0.02),(0.30±0.03),(P＜0.01).胞外信号调节激酶(ERK)磷酸化水平从(1.04±0.04)下调至(0.79±0.06),(0.73 ±0.10),(P＜0.01).p38磷酸化水平从(0.51±0.06)下调至(0.39 ±0.07),(0.29±0.15),(P＜0.05),c-Jun氨基末端激酶(JNK)磷酸化水平从(1.05±0.03)下调至(0.65 ±0.02),(0.66±0.033),(P＜0.01).结论:芪麝丸部分通过抑制MAPK信号转导通路活化过程中关键蛋白胞外信号调节激酶(ERK)、JNK和p38丝裂原活化蛋白激酶(p38)磷酸化,下调iNOS基因和蛋白的表达从而减少NO的产量,同时下调COX-2蛋白表达,而发挥其抗炎效果.     

藏药十八味党参丸提取物对脂多糖诱导的RAW264.7细胞Akt/p38MAPK信号通路及M1/M2极化影响的探究

目的探究藏药十八味党参丸(TEP)的提取物调控脂多糖(LPS)诱导小鼠巨噬细胞RAW 264.7的炎性反应及M1/M2极化分型的探究。方法 Alarmarblue法评价RAW 264.7活力;荧光酶标定量分析细胞活性氧(reactive oxygen species, ROS)水平;Griess法检测上清液中细胞一氧化氮(NO)的分泌情况;流式细胞术检测表面标志物CD206和CCR7蛋白的表达;RT-qPCR法检测细胞白介素(IL)-1β、IL-6、趋化因子2(CCL2)、一氧化氮合酶(iNOS)、精氨酸酶(ARG)-1和肿瘤坏死因子α(TNF-α)基因表达的情况;Western blot法检测TEP调控细胞合成iNOS、蛋白激酶B(Akt)和p38丝裂原活化激酶(p38MAPK)信号通路相关蛋白的表达情况。结果与模型组相比,TEP组一定程度上提高了RAW 264.7的细胞活性,同时抑制了LPS诱导的细胞内ROS水平的升高。经过LPS刺激后,模型组NO表达量显著升高,在24 h后表达量达到最高,而TEP组NO表达显著降低。模型组的CCR7表达升高,CD206表达下降,TEP干预后CCR7表达下降,CD206表达升高,且趋势呈现浓度依赖。与模型组相比,TEP组的IL-1β、IL-6、CCL2、iNOS、ARG和TNF-α基因表达以及iNOS、Akt和p38MAPK蛋白表达水平均显著降低。结论 TEP能够抑制细胞内ROS水平,降低NO分泌和炎性基因的表达水平,抑制细胞的M1表型,促进M2表型,其机制可能与细胞内iNOS、Akt和p38MAPK信号通路蛋白表达被抑制有关。     

Er-Miao-San,a traditional herbal formula containing Rhizoma Atractylodis and Cortex Phellodendri inhibits inflammatory mediators in LPS-stimulated RAW264.7 macrophages through inhibition of NF-κB pathway and MAPKs activation

Ethnopharmacological relevance

Er-Miao-San (EMS) is a traditional Chinese herbal formulation that contains combinations of Rhizoma Atractylodis (RA) and Cortex Phellodendri (CP). It exhibits analgesic and anti-inflammatory activities and have been used for the treatment of various “Bi Zheng” for thousand years in China. The aims of the present study were to investigate the anti-inflammatory activities of EMS and elucidate the underlying mechanisms with regard to its molecular basis of action for the best combination.

Materials and methods

The anti-inflammatory effects of EMS were studied by using lipopolysaccharide (LPS)-stimulated activation of nitric oxide (NO) and pro-inflammatory cytokine production in mouse RAW264.7 macrophages. Expression of inducible NO synthase (iNOS), mitogen-activated protein kinases (MAPKs) phosphorylation, p65 phosphorylation, inhibitor-κBα (IκBα) degradation, and NF-κB DNA-binding activity were further investigated.

Results

The present study demonstrated that EMS could suppress the production of NO in LPS-stimulated RAW264.7 macrophages. However, CP and RA did not have significant inhibitory effect on them. EMS also inhibited the production of tumor necrosis factor-alpha, interleukin-1 beta and macrophage chemotactic protein-1. Further investigations showed EMS could suppress iNOs expression and p38 phosphorylation. EMS significantly decreased the content of IκBα, reduced the level of phosphorylated p65 and suppressed the NF-κB DNA-binding activity. All these results suggested the inhibitory effects of EMS on the production of inflammatory mediators through the inhibition of the NF-κB pathway.

Conclusions

Our results indicated that EMS inhibited inflammatory events and iNOS expression in LPS-stimulated RAW264.7 cells through the inactivation of the MAPK and NF-κB pathway. This study gives scientific evidence validating the use of EMS in treatment of patients with “Bi Zheng” in clinical practice in traditional Chinese medicine.     

Involvement of heme oxygenase-1 in the anti-inflammatory activity of Chrysanthemum boreale Makino extracts on the expression of inducible nitric oxide synthase in RAW264.7 macrophages

Aim of the study

This study is to elucidate the involvement of anti-inflammatory heme oxygenase-1 (HO-1) in the inhibitory activity of a Chrysanthemum boreale Makino (CB) extract on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages.

Materials and methods

Cell viability and NO assay were performed. In addition, iNOS expression was detected by Western blotting and real-time PCR. HO-1 expression was also evaluated by Western blotting, and blocking HO-1 activity on NO production was performed.

Results

The CB extract at the highest concentration (100 μg/ml) significantly inhibited NO production by approximately 90% and suppressed iNOS protein expression by approximately 84.8% compared to LPS-stimulated cells. Furthermore, the CB extract (100 μg/ml) inhibited iNOS mRNA expression in a concentration-dependant manner and suppressed iNOS mRNA expression by 94.8%. The CB extract induced the expression of HO-1 in a dose-dependent manner, and blocking HO-1 activity abolished the inhibitory effects of the CB extract. Moreover, the addition of carbon monoxide such as tricarbonyl dichlororuthenium (II) dimmer (RuCO), a byproduct derived from heme degradation, mimicked the inhibitory action of low concentrations of CB extract.

Conclusion

These results suggest that a CB extract has potent anti-inflammatory activity in RAW264.7 macrophages involving the induction of HO-1.     

Aloe-emodin from rhubarb (Rheum rhabarbarum) inhibits lipopolysaccharide-induced inflammatory responses in RAW264.7 macrophages

Ethnopharmacological relevance

Rheum rhabarbarum (rhubarb) has long been used for the treatment of inflammation in China and other Asian countries. However, the mechanism underlying the anti-inflammatory activity of this medicinal plant is not fully understood. The present study was designed to investigate the anti-inflammatory effects of anthraquinones, the major constituents in rhubarb, and the molecular mechanism involved in their anti-inflammatory effects.

Materials and methods

RAW264.7 cells were stimulated by lipopolysaccharide (LPS) in the presence or absence of the compounds examined. The proliferation of RAW264.7 cells was assayed by the Alamar-Blue method. The quantity of nitric oxide (NO) was determined by Griess assay. The expression of pro-inflammatory cytokines was determined by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR. Inducible nitric oxide synthase (iNOS), inhibitor of nuclear factor κBα (IκBα), extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (MAPK), c-Jun NH2-terminal kinase (JNK), and Akt/phosphoinositide 3-kinase (PI3K) protein expression levels were determined by Western blotting.

Results

Aloe-emodin markedly suppressed the production of NO, interleukin-6 (IL-6), and interleukin-1β (IL-1β) in LPS-stimulated RAW264.7 cells with no apparent cytotoxicity. The mRNA expression levels of iNOS, IL-6, and IL-1β genes were also significantly inhibited by aloe-emodin. Western blot analysis showed that aloe-emodin suppressed LPS-induced iNOS protein expression, IκBα degradation, and the phosphorylation of ERK, p38, JNK, and Akt.

Conclusions

These results demonstrate that aloe-emodin is the bioactive component of rhubarb that confers an anti-inflammatory effect through a likely mechanism involving a decrease in pro-inflammatory cytokine production in LPS-induced RAW264.7 macrophages via inhibition of NF-κB, MAPK, and PI3K pathways.     

Suppressive effect of inducible nitric oxide synthase (iNOS) expression by the methanol extract of Actinodaphne lancifolia

Nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) has played a crucial role in various pathophysiological processes including inflammation and carcinogenesis. Therefore, the inhibitors of NO synthesis or iNOS gene expression have been considered as potential anti-inflammatory and cancer chemopreventive agents. In our continuous search for iNOS inhibitors from natural products we have evaluated indigenous Korean plant extracts using an assay for inhibition of nitric oxide formation on lipopolysaccharide (LPS)-activated mouse macrophage RAW 264.7 cells. As a result, the methanolic stem extract of Actinodaphne lancifolia showed an inhibitory activity of NO production in a dose-dependent manner (IC50 = 2.5 microg/ml). Additional study demonstrated that the extract of Actinodaphne lancifolia significantly suppressed the iNOS protein and gene expression in a dose-dependent manner. These results suggest that Actinodaphne lancifolia could be a potential candidate for developing an iNOS inhibitor from natural products. Further elucidation of active principles for development of new cancer chemopreventive and/or anti-inflammatory agents could be warranted.     

Heme oxygenase-1 mediates the anti-inflammatory effect of mushroom Phellinus linteus in LPS-stimulated RAW264.7 macrophages

This work aimed to elucidate the anti-inflammatory mechanism of the n-BuOH subfraction (PL) prepared from fruiting bodies of Phellinus linteus. PL induced heme oxygenase-1 (HO-1) of the RAW264.7 macrophages in concentration- and time-dependent manner. It suppressed induction of inducible nitric oxide synthase (iNOS) and subsequent production of nitric oxide (NO) through down-regulation of iNOS promoter activity in lipopolysaccharide (LPS)-stimulated macrophages. Zn(II) protoporphyrin IX (ZnPP), a specific inhibitor of HO-1, partly blocked suppression by PL on iNOS promoter activity and NO production, which were elevated in LPS-stimulated macrophages. LPS was able to enhance NO production via reactive oxygen species (ROS) generation, c-Jun NH(2)-terminal kinase (JNK) and c-Jun induction. ZnPP prevented PL from down-regulating ROS generation and JNK activation in LPS-stimulated macrophages. Taken together, PL shows its anti-inflammatory activity via mediation of HO-1 in an in vitro inflammation model.     

Effects of ethanol and water extracts of propolis (bee glue) on acute inflammatory animal models

The anti-inflammatory effects of ethanol (EEP) and water (WSD) extracts in ICR mice and Wistar rats were analyzed. Both WSD and EEP exhibited significant anti-inflammatory effects in animal models with respect to thoracic capillary vessel leakage in mice, carrageenan-induced oedema, carrageenan-induced pleurisy, acute lung damage in rats. The mechanisms for the anti-inflammatory effects probably involve decreasing prostaglandin-E₂ (PGE₂) and nitric oxide (NO) levels. In rats with Freund's complete adjuvant (FCA) induced arthritis, propolis extracts significantly inhibited the increase of interleukin-6 (IL-6) in inflamed tissues, but had no significant effect on levels of interleukin-2 (IL-2) and interferon-γ (IFN-γ). The results are consistent with the interpretation that EEP and WSD may exert these effects by inhibiting the activation and differentiation of mononuclear macrophages.     

Shikonin derivatives inhibited LPS-induced NOS in RAW 264.7 cells via downregulation of MAPK/NF-kappaB signaling

AIM OF THE STUDY: Shikonin/alkannin (SA) derivatives, analogs of naphthoquinone pigments, are the major components of root extracts of the Chinese medicinal herb (Lithospermum erythrorhizon; LE) and widely distributed in several folk medicines. In the present study, the effect and the underline molecular mechanism of shikonin derivatives isolated from root extracts of Lithospermum euchroma on lipopolysaccharide (LPS)-induced inflammatory response were investigated. MATERIALS AND METHODS: Effects of five SA derivatives, including SA, acetylshikonin, beta,beta-dimethylacrylshikonin, 5,8-dihydroxy-1.4-naphthoquinone, and 1,4-naphthoquinone on LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production in mouse macrophage RAW264.7 cells were examined. RESULTS: Data suggested that SA derivatives inhibited LPS-induced NO and PGE(2) production, and iNOS protein expression. RT-PCR analysis showed that SA derivatives diminished LPS-induced iNOS mRNA expression. Moreover, the phosphorylation of extracellular signal-regulated kinase (ERK)1/2 in LPS-stimulated RAW 264.7 cells was concentration-dependently suppressed by SA derivatives. SA inhibited NF-kappaB activation by prevention of the degradation of inhibitory factor-kappaB and p65 level in nuclear fractions induced by LPS. CONCLUSIONS: Taken together, these results suggest that the anti-inflammatory properties of SA derivatives might result from inhibition of iNOS protein expression through the downregulation of NF-kappaB activation via suppression of phosphorylation of ERK, in LPS-stimulated RAW 264.7 cells.     

Fermentation improves anti-inflammatory effect of sipjeondaebotang on LPS-stimulated RAW 264.7 cells

Sipjeondaebotang (SJ) has been used as a traditional drug in east-Asian countries. In this study, to provide insight into the biological effects of SJ and SJ fermented by Lactobacillus, we investigated their effects on lipopolysaccharide (LPS)-mediated inflammation in macrophages. The investigation was focused on whether SJ and fermented SJ could inhibit the production of pro-inflammatory mediators such as prostaglandin (PG) E(2) and nitric oxide (NO) as well as the expressions of cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS), tumor necrosis factor (TNF)-α, mitogen-activated protein kinases (MAPKs) and nuclear factor (NF)-κB in LPS-stimulated RAW 264.7 cells. We found that SJ modestly inhibited LPS-induced PGE(2), NO and TNF-α production as well as the expressions of COX-2 and iNOS. Interestingly, fermentation significantly increased its inhibitory effect on the expression of all pro-inflammatory mediators. Furthermore, fermented SJ exhibited increased inhibition of p38 MAPK and c-Jun NH(2)-terminal kinase (JNK) MAPK phosphorylation as well as NF-κB p65 translocation by reduced IκBα degradation compared with either untreated controls or unfermented SJ. High performance liquid chromatography (HPLC) analysis showed fermentation by Lactobacillus increases liquiritigenin and cinnamyl alcohol contained in SJ, which are known for their anti-inflammatory activities. Finally, SJ fermented by Lactobacillus exerted potent anti-inflammatory activity by inhibiting MAPK and NF-κB signaling in RAW 264.7 cells.