Molecular mechanism of anti-inflammatory activity of Pluchea indica leaves in macrophages RAW 264.7 and its action in animal models ofinflammation

Ethnopharmacological relevance: Pluchea indica Less.

(Asteraceae) is a Thai medicinal plant used in traditional medicine for the treatment of hemorrhoids, lumbago, leucorrhoea and inflammation. This study investigated the molecular mechanism of anti-inflammatory activity of Pluchea indica leaf extract in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and also determined its action in acute inflammation animal models.

Materials and methods

The inhibitory effect of Pluchea indica leaf extract on LPS-induced nitric oxide (NO) production was evaluated by Griess reaction. Protein and mRNA expressions were determined by real time RT-PCR and Western blotting analysis, respectively. Inducible nitric oxide synthase (iNOS) promoter activity was evaluated by iNOS promoter based reporter gene assay. In vivo anti-inflammatory effect was examined in ethylphenylpropiolate (EPP)-induced ear edema and carrageenan-induced paw edema in rat models.

Results

Ethyl acetate fraction of ethanol extract of Pluchea indica leaves (EFPI) exhibited the potent inhibitory effect on NO production in LPS-induced macrophages and also inhibited PGE₂ release. EFPI reduced iNOS mRNA and protein expression through suppressed iNOS promoter activity and nuclear translocation of subunit p65 of nuclear factor-κB, but did not inhibit phosphorylation of the mitogen-activated protein kinases (MAPKs). Moreover, EFPI possessed anti-inflammatory activities on acute phase of inflammation as seen in EPP-induced ear edema and carrageenan-induced paw edema inrats.

Conclusions

These data support the pharmacological basis of Pluchea indica plant as a traditional herbal medicine for treatment of inflammation.     

Anti-inflammatory activity of a water extract of Acorus calamus L. leaves on keratinocyte HaCaT cells

Ethnopharmacological relevance

Acorus calamus L., sweet flag, is a well-known medicinal plant that grows worldwide wildly along swamps, rivers, and lakes.

Aim of the study

The aim of this study was to evaluate the anti-inflammatory activity of Acorus calamus leaf (ACL) extract and to explore its mechanism of action on human keratinocyte HaCaT cells.

Materials and methods

HaCaT cells treated with polyinosinic:polycytidylic acid (polyI:C) and peptidoglycan (PGN) induced the inflammatory reactions. The anti-inflammatory activities of ACL were investigated using RT-PCR, ELISA assay, immunoblotting, and immunofluorescence staining.

Results

HaCaT cells induced the pro-inflammatory cytokines, interleukin-8 (IL-8) and/or interleukin-6 (IL-6) expressions after treatment with polyI:C or PGN. ACL inhibited the expression of IL-8 and IL-6 RNA and protein levels, and attenuated the activation of NF-κB and IRF3 after polyI:C treatment. ACL also inhibited expression of IL-8 and activation of NF-κB following PGN induction.

Conclusions

These results suggest that ACL inhibits the production of pro-inflammatory cytokines through multiple mechanisms and may be a novel and effective anti-inflammatory agent for the treatment of skin diseases.     

Dichroa febrifuga Lour. inhibits the production of IL-1β and IL-6 through blocking NF-κB, MAPK and Akt activation in macrophages

Aim of the study

The roots of Dichroa febrifuga Lour. have been used as a traditional antimalarial drug and also used in the treatment of productive cough and unstable fever caused by infection in China and Korea. In this study, we evaluated the anti-inflammatory effect and underlying molecular mechanism of aqueous extract of Dichroa febrifuga (AEDF) in C57BL/6 mouse peritoneal macrophages.

Materials and methods

The effect of AEDF on proinflammatory cytokine (IL-1β and IL-6) production was analyzed by ELISA and real-time RT-PCR. The effects of AEDF on NF-κB/IκB-α/IKK were measured by reporter assay (in RAW 264.7 cells), EMSA, Western blotting and kinase assay. The effects of AEDF on Akt and MAPKs activity were assayed by Western blotting.

Results

AEDF inhibited the production of IL-1β and IL-6, NF-κB activation, IκB-α degradation, and IKK, Akt, ERK1/2 and JNK activities in LPS-stimulated mouse peritoneal macrophages.

Conclusions

These results suggest that AEDF inhibits proinflammatory cytokine (IL-1β and IL-6) production in LPS-stimulated mouse peritoneal macrophages, and that these effects are mediated by the inhibition of the activity of IKK/IκB/NF-κB and the phosphorylation of Akt, ERK1/2, and JNK. Our results provide a molecular basis for understanding the inhibitory effects of Dichroa febrifuga roots on endotoxin-mediated inflammation.     

Chrysanthemum indicum Linné extract inhibits the inflammatory response by suppressing NF-κB and MAPKs activation in lipopolysaccharide-induced RAW 264.7 macrophages

Aims of study

Although the flowers of Chrysanthemum indicum Linné (Asteraceae) have long been used in traditional Korean and Chinese medicine to treat inflammatory diseases, the underlying mechanism(s) by which these effects are induced remains to be defined. We investigated the effects of a 70% ethanolic extract of C. indicum (CIE) on the activities of cellular signaling molecules that mediate inflammatory responses.

Materials and methods

Production of NO, PGE₂, TNF-α, and IL-1β by ELISA, mRNA and protein expression of iNOS and COX-2, phosphorylation of MAPKs, and activation of NF-κB by RT-PCR and Western blotting were examined in LPS-induced RAW 264.7 macrophages.

Results

The CIE strongly inhibited NO, PGE₂, TNF-α, and IL-1β production, and also significantly inhibited mRNA and protein expression of iNOS and COX-2 in LPS-induced RAW 264.7 macrophages, in a dose-dependent manner. Furthermore, the CIE clearly suppressed nuclear translocation of NF-κB p65 subunits, which correlated with an inhibitory effect on IκBα phosphorylation. The CIE also attenuated the activation of ERK1/2 and JNK in a dose-dependent manner.

Conclusion

Our results suggest that the anti-inflammatory properties of CIE might result from the inhibition of inflammatory mediators, such as NO, PGE₂, TNF-α, and IL-1β, via suppression of MAPKs and NF-κB-dependent pathways.     

The production of nitric oxide and prostaglandin E2 in peritoneal macrophages is inhibited by Andrographis paniculata, Angelica sinensis and Morus alba ethyl acetate fractions

Aim of the study

Traditional Chinese medicine herbs (TCMHs) are used in medicines as well as in daily dietary supplements in Asia. In this study, we employed pNF-κB-Luc or pIFN-γ-Luc and BALB/c mice peritoneal macrophages or splenocytes to investigate both the immune and inflammatory effects of six selected plant species.

Materials and Methods

Specifically, we used ethyl acetate fractions of Astragalus membranaceus (Fisch.) Bunge var. mongholicus (Bunge) Hsiao (Fabaceae) (AM), Andrographis paniculata (Burm. f.) Nees (Acanthaceae) (AP), Angelica sinensis (Oliv.) Diels (Apiaceae) (AS), Eucommia ulmodes Oliv. (Eucommiaceae) leaves (EU leaves), Isatis indigotica Fort. (Brassicaceae) (II) and Morus alba L. (Moraceae) (MA).

Results

We found that ethyl acetate fractions of AP, AS and MA significantly decreased NF-κB luciferase activity and also the secretion of NO and PGE₂ in LPS/IFN-γ stimulated mouse peritoneal macrophages (p < 0.05). In contrast, they did not affect IFN-γ luciferase activity or IFN-γ production in concanavalin A (Con A)-activated mouse splenocytes. Our results indicated that the anti-inflammatory properties of these plant extracts might be resulted from the inhibition of pro-inflammatory mediators (e.g., NO and PGE₂), at least in part via suppression of a signaling pathway such as NF-κB.

Conclusions

Collectively, we have found that three potent bioactive TCMH species exerted significant NF-κB inhibitory activity and acted in a cell type dependent fashion.     

Flower extract of Panax notoginseng attenuates lipopolysaccharide-induced inflammatory response via blocking of NF-κB signaling pathway in murine macrophages

Aim of the study

The root of Panax notoginseng (PN) is commonly used to treat chronic liver disease with its therapeutic abilities to stop haemorrhage in the circulation, while the PN flower (PN-F) is largely unknown in the biological activities on inflammation and mechanisms of its actions. In this study, the pharmacologic effects of PN-F methanol extract on inflammation were investigated to address potential therapeutic or toxic effects in LPS-stimulated mouse macrophage cells, RAW264.7 cells.

Materials and methods

Production of NO, PGE₂ and pro-inflammatory cytokines (TNF-α and IL-1β) in supernatant, the expression of iNOS, COX-2 and cytokines, the phosphorylation of MAPK moleduces (ERK1/2, JNK and p38 MAPK), and the activation of NF-κB in PN-F extract were assayed in LPS-stimulated RAW264.7 cells.

Results

PN-F extract significantly inhibited the productions of NO, PGE₂, TNF-α and IL-1β on the LPS-stimulated RAW264.7 cells. In addition, PN-F extract suppressed the mRNA and protein expressions of iNOS, COX-2, TNF-α and IL-1β in LPS-stimulated RAW264.7 cells. The molecular mechanism of PN-F extract-mediated attenuation in RAW264.7 cells has close a relationship to suppressing the phosphorylation of MAPK molecules such as ERK1/2, JNK and p38 MAPK, and the translocation of NF-κB p65 subunit into nuclear.

Conclusion

These results indicate that PN-F extract inhibits LPS-induced inflammatory response via the blocking of NF-κB signaling pathway in macrophages, and demonstrated that PN-F extract possesses anti-inflammatory properties in vitro.     

The effect of the aqueous extract of Helietta parvifolia A. Gray (Rutaceae) stem bark on carrageenan-induced paw oedema and granuloma tissue formation in mice

Aims of study

Despite the ethnopharmacological relevance of Helietta parvifolia A. Gray (Rutaceae) in Mexico, we found no significant pharmacological studies of this plant in the scientific literature. The aim of the present study was to establish the anti-inflammatory effect of an aqueous extract of the stem bark of Helietta parvifolia in mice.

Materials and methods

The anti-inflammatory activity of the aqueous extract of the stem bark of Helietta parvifolia was evaluated using carrageenan-induced paw oedema in mice, and the cotton pellet granuloma method.

Results

An extract dose ranging from 20 to 80 mg/kg p.o. showed a non-significant effect over the initial phase of carrageenan-induced oedema. However, it showed a significant inhibition of oedema after 3 h, which can be related to the inhibition of the release of kinin-like substances. An ID₅₀ value of 47.4 mg/kg was obtained for the plant extract. The extract also suppressed granulomatous tissue formation during chronic inflammation. The inhibitory values were 19.2, and 22.2, corresponding to 40 and 80 mg/kg doses of extract respectively.

Conclusions

Aqueous extract showed a statistically significant anti-inflammatory effect in mice during the late phase of acute inflammation and during chronic inflammation. However, the exact mechanism(s) of anti-inflammatory effects of Helietta parvifolia observed in this study remains unclear.     

Molecular mechanism of capillarisin-mediated inhibition of MyD88/TIRAP inflammatory signaling in in vitro and in vivo experimental models

Ethnopharmacological relevance

Artemisia capillaris Thunberg (Compositae) have been used as traditional medicine as a diuretic, liver protective agent, and for amelioration of inflammatory and analgesic disorders. The present study was carried out to establish the scientific rationale for treating inflammation and to find active principles from A. capillaris.The aim of the present study is to investigate the possible anti-inflammatory mechanism of the major component (capillarisin) isolated from A. capillaris via inhibition of MyD88/TIRAP inflammatory signaling both in vitro and in vivo models.

Materials and methods

The nitrite, PGE₂, and TNF-α productions were evaluated by Griess reagent and ELISA kits. The protein and mRNA expression levels were investigated by Western blot and RT-PCR. The NF-κB and AP-1 DNA-binding was performed by electrophoretic mobility shift assay. The CFA- and carrageenan-induced paw edema was performed in ICR mice in which 20 and 80 mg/kg body weight of capillarisin was administered intraperitoneally (i.p.).

Results

The results demonstrated that pretreatment with capillarisin effectively inhibited the LPS-induced activation of NF-κB, Akt, and MAP kinase-activated inflammatory genes, which is mediated by MyD88 and TIRAP. Treatment with capillarisin reduced the mRNA and protein levels of iNOS and COX-2 in RAW 264.7 cells as assessed by RT-PCR and Western blot. Capillarisin suppressed LPS-induced inhibitory kappa kinase (IKK) phosphorylation and the degradation of inhibitory kappa B (IκBα) and prevented the nuclear translocation of p65 and p50. Capillarisin also exhibited a promising inhibitory effect on the LPS-induced NF-κB and AP-1 DNA binding activity based on an electrophoretic mobility shift assay. The LPS-induced activation of p-JNK, p-p38, p-ERK, and p-Akt was significantly inhibited. In addition, the TNF-α level in the media was effectively reduced by capillarisin. In vivo experimental analysis revealed that capillarisin (20 and 80 mg/kg, i.p.) inhibited complete Freund's adjuvant (CFA)-and carrageenan-induced paw edema, nitrite production in plasma, and TNF-α, a pro-inflammatory cytokine production.

Conclusion

The results presented here demonstrate that capillarisin has consistent anti-inflammatory properties and acts by inhibiting inflammatory mediators in in vitro and in vivo experimental models, and suggest its potential utility in the control of inflammatory disorders.     

Anti-inflammatory,anti-angiogenic and anti-nociceptive activities of an ethanol extract of Salvia plebeia R. Brown

Ethnopharmacological relevance

Salvia plebeia R. Brown has been used for the treatment of a variety of inflammatory diseases, cold and tumors in many countries, including Korea and China.

Aim of the study

This study aimed to assess anti-inflammatory and related activities of an ethanol extract (SPEE) prepared from the dried whole parts of Salvia plebeia.

Materials and methods

Anti-angiogenic and anti-nociceptive activities of SPEE were analyzed using the chick chorioallantoic membrane (CAM) assay and acetic acid-induced writhing response, respectively. Anti-inflammatory activity of SPEE was evaluated using acetic acid-induced vascular permeability, carrageenan-induced inflammation in the air pouch and analyses of nitrite content and induced nitric oxide synthase (iNOS) level in the macrophage cells.

Results

SPEE gave rise to a significant inhibition in chick chorioallantoic membrane angiogenesis. SPEE exhibited anti-inflammatory activities in vascular permeability and air-pouch models. In the air-pouch model, SPEE was able to diminish exudate volume, number of polymorphonulcear leukocytes and nitrite content. SPEE also displayed anti-nociceptive activity in the writhing response model in mice. SPEE significantly decreased nitrite content and induced nitric oxide synthase (iNOS) in the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells, while it could not modulate cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 levels in the stimulated phages. SPEE decreased reactive oxygen species (ROS) level in the stimulated macrophages.

Conclusion

The ethanol extract (SPEE) of Salvia plebeia possesses anti-inflammatory and related anti-angiogenic, anti-nociceptive and antioxidant activities, which offers partial support to its folkloric use.     

Anti-inflammatory effects of ethyl acetate fraction from Melilotus suaveolens Ledeb on LPS-stimulated RAW 264.7 cells

Aim of the study

This paper aimed to elucidate the anti-inflammatory effects of EtOAc fraction prepared from Melilotus suaveolens Ledeb ethanol extract with a cellular model of LPS-stimulated RAW 264.7 cell.

Materials and methods

Some key pro-inflammatory cytokines and mediators including IL-1β, IL-6, NO, iNOS, COX-2 and TNF-α, two important anti-inflammatory cytokines and mediators IL-10 and HO-1, I-κB and NF-κB were studied by sandwich ELISA, real-time PCR, western blot analysis and immunocytochemistry. At last a HPLC fingerprint was taken to evaluate the fraction.

Results

The EtOAc fraction could significantly inhibit the production of IL-1β, IL-6, NO, TNF-α, COX-2 in LPS-stimulated cell than that of single LPS-stimulated cell (p < 0.01 or p < 0.05), and the extract could increase the production of IL-10 and HO-1 than that of single LPS intervention cell (p < 0.01 or p < 0.05). Meanwhile, the extract also could inhibit the production of NF-κB compared to single LPS-stimulated cell. All the results showed that the extract had a good anti-inflammatory effect on LPS-stimulated RAW264.7 cell.

Conclusions

Taken together, the anti-inflammatory actions of M. suaveolens Ledeb EtOAc fraction might be due to the down-regulation of IL-1β, IL-6, NO, TNF-α and COX-2 via the suppression of NF-κB activation, and another pathway was up regulating the production of IL-10 and HO-1. Meanwhile, the EtOAc fraction might be further studied to isolate the active anti-inflammatory ingredients besides coumarin.     

Anti-inflammatory and analgesic effects of ethanol and aqueous extracts of Pterocephalus hookeri (C.B. Clarke) Höeck

Aim of the study

This study evaluates the anti-inflammatory and analgesic activities of the ethanol and aqueous extracts of a Tibetan herb Pterocephalus hookeri (C.B. Clarke) Höeck to provide experimental evidence for its traditional use such as cold, flu and rheumatoid arthritis.

Materials and methods

Investigations on the analgesic effects of P. hookeri (C.B. Clarke) Höeck were carried out, including hot-plate test and acetic acid-induced writhing. The anti-inflammatory activities were observed by utilizing the following models: carrageenin-induced edema of the hind paw of rats, cotton pellet-induced granuloma formation in rats, acetic acid-induced permeability, and xylene-induced ear edema in mice. The effects of the administration of indomethacin were also studied.

Results

It has been shown that the ethanol and aqueous extracts significantly increased the hot-plate pain threshold and reduced acetic acid-induced writhing response in mice. The ethanol and aqueous extracts remarkably inhibited the increase in vascular permeability induced by acetic acid and ear edema induced by xylene. The ethanol extract also significantly decreased the carrageenin-induced rat paw edema perimeter and inhibited the increase of granuloma weight.

Conclusion

The results show that the ethanol and aqueous extracts have both central and peripheral analgesic activities and as anti-inflammatory effects, supporting the traditional application of this herb in treating various diseases associated with inflammation and pain.     

Evaluation of anti-inflammatory potential of Chloranthus erectus (Buch.-Ham.) Verd. leaf extract in rats

Aim of the study

Chloranthus erectus (Buch.-Ham.) Verdcourt (Chloranthaceae) is a shrub native to tropical and temperate zone of Eastern Himalaya of India and South-East Asia and have traditionally been used as a folklore medicine to treat localised swelling, joint pain, skin inflammation, fever and bodyache. In this study, an attempt has been made to demonstrate the anti-inflammatory activity of methanol extract obtained from Chloranthus erectus leaves (MECEL) in acute, sub-acute and chronic mouse models.

Materials and methods

Inflammation in the hind paw of Wistar albino rat was induced by carrageenan, histamine and serotonin, and tissue granuloma pouch was induced by cotton pellet method. Anti-inflammatory drug—phenylbutazone was used as standard drug for comparison.

Results

In acute carrageenan-induced rat hind paw edema, oral administration of MECEL at 200 mg/kg produced significant inhibition of edema by 38.34% (p < 0.01) while the histamine- and serotonin-induced sub-acute model, the inhibition of paw edema reached 52.54% (p < 0.001) and 25.5% (p < 0.01), respectively. In a 7-day study, MECEL at 20 and 50 mg/kg produced significant suppression of cotton pellet-induced tissue granuloma formation in rats.

Conclusions

This preliminary study revealed that the methanol extract of Chloranthus erectus exhibited significant anti-inflammatory activity in the tested models, and may provide the scientific rationale for its popular folk medicine as anti-inflammatory agent.     

Suppression of lipopolysaccharide-induced inflammatory responses in RAW 264.7 murine macrophages by aqueous extract of Clinopodium vulgare L. (Lamiaceae)

Ethnopharmacological relevance

The wild basil Clinopodium vulgare L. is commonly used in Bulgarian folk medicine for treatment of irritated skin, mastitis- and prostatitis-related swelling, as well as for some disorders accompanied with significant degree of inflammation (e.g. gastric ulcers, diabetes, and cancer).

Aim of study

To determine the effect of aqueous extract of Clinopodium vulgare L. on LPS-induced inflammatory responses of murine RAW 264.7 macrophages.

Materials and methods

Cell cytotoxicity was evaluated by MTT assay. Protein expression levels were monitored by Western blot analysis. Production of NO and PGE₂ was measured by the Griess colorimetric method and enzyme immunoassay, respectively. Activation of MMP-9 was visualized by gelatin zymography. Cytokine levels were determined by BioPlex assay. Intracellular ROS and free radical scavenging potential were measured by DCFH-DA and DPPH method, respectively. Xanthine oxidase activity was evaluated spectrophotometrically.

Results

The extract suppresses NF-κB activation by preventing Iκ-B phosphorylation and inhibits the phosphorylation of p38 and SAPK/JNK MAPKs. It down-regulates iNOS expression which manifests as a drastic decrease of NO production, inhibits MMP-9 activation, but does not affect COX-2 protein levels and reduces only slightly the released PGE₂. Secretion of IL-1β and Il-10 is greatly reduced, whereas suppression of TNF-α and GM-CSF production is less dramatic. The extract has strong free radical scavenging properties and exerts inhibitory effect on xanthine oxidase activity, which lowers the levels of intracellular ROS.

Conclusion

The study provides evidence for the anti-inflammatory potential of Clinopodium vulgare L. aqueous extract.     

Chemopreventive action of Lygodium flexuosum extract in human hepatoma PLC/PRF/5 and Hep 3B cells

Ethnopharmacological relevance

Lygodium flexuosum (Lygodiaceae), a medicinal fern used in Indian traditional medicine against liver disorders.

Aim of the study

The rationale of the study was to examine whether the n-hexane extract from plant Lygodium flexuosum affects apoptosis on human hepatoma PLC/PRF/5 and Hep 3B cells.

Materials and methods

Chemopreventive activity of the Lygodium flexuosum extract was determined by MTT assay, annexin-V FITC binding to phosphatidyl serine and cleavage of PARP. Subdiploid condition of cells treated with Lygodium flexuosum was analyzed by flow cytometry. Further, used transiently transfected NF-κB reporter in PLC/PRF/5 cells to evaluate the inhibitive effect of Lygodium flexuosum extract.

Results

Lygodium flexuosum extract inhibited the cell viability and induced apoptosis in hepatoma cells in a concentration dependent manner as evidenced by apoptotic changes such as flipping of phosphatidyl serine, cleavage of PARP. Cell cycle analysis showed the subG1 apoptotic population in cells treated with higher concentrations of the extract. When activated with exogenous TNF-α in transfected hepatoma cells it was observed that NF-κB dependent gene expression was inhibited by treatment with Lygodium flexuosum extract in PLC/PRF/5 cells dose-dependently.

Conclusions

This investigation suggests that the Lygodium flexuosum extract has antiproliferative and apoptotic activity in both cancer cells and has inhibitive role in TNF-α induced NF-κB activation in PLC/PRF/5 cells confirms the potential of the extract as a chemopreventive agent.     

Suppressive effects of wild bitter gourd (Momordica charantia Linn. var. abbreviata ser.) fruit extracts on inflammatory responses in RAW 264.7 macrophages

Aim of the study

Bitter gourd (Momordica charantia) is used to treat various diseases including inflammation. A wild species of bitter gourd, Momordica charantia Linn. var. abbreviata ser. (WBG), is considered to be more potent in disease prevention than is bitter gourd; however, little is known about the biological and physiological characteristics of WBG.

Materials and methods

The present study investigated the anti-inflammatory effect of WBG on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages.

Results

Among the hot water, 95% ethanol, and ethyl acetate extracts of WBG, the ethanol extract showed the greatest reduction of LPS-induced nitric oxide (NO) and prostaglandin E₂ (PGE₂) production and inducible nitric oxide synthase (iNOS) and pro-interleukin-1β expression. LPS-induced cyclooxygenase-2 expression was not affected by WBG extracts. Compared with WBG, extracts from bitter gourd showed a lesser inhibition of LPS-induced events. Electrophoretic mobility shift assay further showed that both the hot water and the ethanol extracts of WBG inhibited NF-κB activation. Although information is lacking on the bioactive components of WBG, the phenolic compound contents of each extract significantly paralleled its anti-inflammatory ability (r = 0.74, 0.88 and 0.65 for NO, PGE₂ and iNOS expression, respectively, P < 0.05).

Conclusions

These results suggest that WBG is beneficial for reducing LPS-induced inflammatory responses by modulating NF-κB activation.