4-Hydroxykobusin Inhibits the Induction of Nitric Oxide Synthase by Inhibiting NF-.KAPPA.B and AP-1 Activation

Host defense peptide LEAP-2 contributes to monocyte/macrophage polarization in barbel steed (Hemibarbus labeo)

The liver-expressed antimicrobial peptide 2 (LEAP-2) plays a vital role in host immunity against pathogenic organisms. In the present study, cDNA of the LEAP-2 gene was cloned and sequenced from the barbel steed (Hemibarbus labeo). The predicted amino acid sequence of the barbel steed LEAP-2 comprises a signal peptide and a prodomain, which is followed by the mature peptide. Sequence analysis revealed that barbel steed LEAP-2 belongs to the fish LEAP-2A cluster and that it is closely related to zebrafish LEAP-2A. We found that barbel steed LEAP-2 transcripts were expressed in a wide range of tissues, with the highest mRNA levels detected in the liver. In response to lipopolysaccharide (LPS) treatment, LEAP-2 was significantly upregulated in the liver, head kidney, spleen, gill, and mid intestine. A chemically synthesized LEAP-2 mature peptide exhibited selective antimicrobial activity against several bacteria in vitro. Moreover, LEAP-2, alone or in combination with LPS or phorbol 12-myristate 13-acetate, strongly induced a pro-inflammatory reaction in barbel steed monocytes/macrophages (MO/MФ), involving the induction of iNOS activity, respiratory burst, and the pro-inflammatory cytokines IFN-γ, TNF-α, and IL-1β. Collectively, the results of this study indicate the importance of fish LEAP-2 in the M1-type polarization of MO/MΦ.

Inhibition of HYBID (KIAA1199)-mediated hyaluronan degradation and anti-wrinkle effect of Geranium thunbergii extract

BACKGROUND

Hyaluronan (HA) is an essential constituent of extracellular matrix in the skin. HA reduction in the dermis and overexpression of HYBID (KIAA1199), a key molecule for HA degradation in skin fibroblasts, are implicated in facial skin wrinkling.

AIMS

We aimed to obtain anti-wrinkle agent(s) by screening for inhibition of HYBID-mediated HA degradation.

METHODS

Various plant extracts were screened for inhibition of HA degradation in HYBID-stable transfectants in HEK293 (HYBID/HEK293). Inhibition of HA-degrading activity and HYBID mRNA and protein expression by Geranium thunbergii extract was studied in skin fibroblasts and HYBID/HEK293 cells. Size distribution of newly produced HA was evaluated by preparing metabolically radiolabeled HA in skin fibroblasts. A double-blind, randomized, and placebo-controlled study was performed in healthy Japanese women (n = 21) by topically treating each side of the face with a lotion formulated with G. thunbergii extract or placebo for 8 weeks.

RESULTS

Among the plant extracts tested, only G. thunbergii extract abolished HA depolymerization in skin fibroblasts and HYBID/HEK293 cells by down-regulating HYBID mRNA and protein expression and by inhibiting HYBID-mediated HA-degrading activity. Although untreated skin fibroblasts produced polydispersed HA, G. thunbergii extract-treated cells produced high-molecular-weight HA. Treatment with G. thunbergii extract-formulated lotion significantly improved skin elasticity and reduced skin wrinkling scores at the outer eye corner compared with the placebo formulation.

CONCLUSIONS

Geranium thunbergii extract inhibited HYBID-mediated HA degradation in vitro and showed anti-wrinkle activity in vivo accompanying the improvement in skin elasticity. Our study provides a possible strategy for anti-wrinkle care through inhibition of HYBID-mediated HA degradation.

Lignan derivatives from Selaginella tamariscina and their nitric oxide inhibitory effects in LPS-stimulated RAW 264.7 cells

The chemical characterization of Selaginella tamariscina leaves resulted in the isolation of five lignanoside derivatives (1-4 and 6) and one neolignan (5). These compounds include three new lignanosides, tamariscinosides D-F (1-3), and one liriodendrin (4) that were isolated for the first time from this plant, together with two known compounds, (2R,3S)-dihydro-2-(3,5-dimethoxy-4-hydroxyphenyl)-7-methoxy-5-acetyl-benzofuran (5) and moellenoside B (6). The chemical structures of these isolated compounds were determined using 1D and 2D NMR, MS, and CD spectroscopic data, and the results were compared to data previously reported in the literatures. These compounds were also evaluated in terms of their inhibition of NO production in lipopolysaccharide (LPS)-stimulated activity in the macrophage cell line RAW 264.7. Among them, compounds 1, 2, 5, and 6 exhibited a significant inhibition with IC₅₀ values ranging from 32.3 to 55.8μM.

Anti-inflammatory effects of essential oils extracted from Chamaecyparis obtusa on murine models of inflammation and RAW 264.7 cells

Antimicrobial, antifungal and anti-inflammatory effects of essential oils extracted from Chamaecyparis obtusa (EOCO) have previously been reported. In the present study, the anti-inflammatory effects of EOCO were investigated in two murine models of inflammation: Carrageenan-induced paw edema and thioglycollate-induced peritonitis, and in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. The expression levels of proinflammatory cytokines were analyzed by ELISA, the expression of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were determined by western blotting, and nitrite concentration was measured using Griess reagent. In mice with carrageenan-induced edema, paw thickness and the expression levels of interleukin (IL)‑1β and IL-6 in paw homogenates were significantly decreased in the EOCO (5 and 10 mg/kg) group, as compared with the control group. In mice with thioglycollate-induced peritonitis, treatment with EOCO (5 and 10 mg/kg) reduced the number of total cells and suppressed tumor necrosis factor‑α (TNF‑α), IL‑1β and IL‑6 levels in peritoneal fluid. In addition, EOCO reduced nitric oxide, TNF‑α and IL‑6 production, and suppressed iNOS and COX‑2 expression in LPS‑stimulated RAW 264.7 cells. These results suggest that EOCO may exert anti‑inflammatory effects in vivo and in vitro, and that these effects may be associated with the inhibition of inflammatory mediators. Therefore, EOCO may be considered an effective therapeutic agent for the treatment of inflammatory diseases.

In vitro anti-inflammatory effect of picrasmalignan A by the inhibition of iNOS and COX‑2 expression in LPS‑activated macrophage RAW 264.7 cells

Picrasma quassioides (P. quassioides) has been widely used as a traditional Chinese medicine for clearing fever and detoxification. Previous phytochemical studies have identified a novel dihydrobenzofuran-type neolignan, picrasmalignan A, isolated from the stems of P. quassioides. In the present study, the in vitro anti-inflammatory effects and molecular mechanisms of picrasmalignan A have been investigated in cultured RAW 264.7 cells, a mouse macrophage‑like cell line. A Griess assay was used to demonstrate the inhibitory effect of picrasmalignan A on the overproduction of nitric oxide (NO). An enzyme-linked immunosorbent assay was used to determine the levels of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). The inhibitory effect on the enzymatic activity of cyclooxygenase 2 (COX‑2) and inducible nitric oxide synthase (iNOS) was observed by colorimetric and fluorimetric assays, respectively. Western blotting was conducted to detect the expression of iNOS and COX-2. Results showed that picrasmalignan A suppressed lipopolysaccharide-stimulated NO production and pro-inflammatory cytokine secretion, including TNF-α and IL-6, in a dose-dependent manner. It also significantly inhibited the expression and enzymatic activity of iNOS and COX-2. These results may demonstrate the anti-inflammatory mechanism of picrasmalignan A.

Rearranged limonoids and chromones from Harrisonia perforata and their anti-inflammatory activity

Two new rearranged limonoids, harperforatin (1) and harperfolide (2), and a new chromone, harperamone (3), were isolated from fruits and roots of Harrisonia perforata, together with eight known compounds. Their structures were elucidated on the basis of spectroscopic data. Harperfolide (2) exhibited potent anti-inflammatory activity by suppressing nitric oxide (NO) production from activated macrophages with IC50 value of 6.51 μM. Furthermore, its effect is mediated by reduction of iNOS protein expression, attributable to the inhibitory action of LPS-induced NO production.

In vitro and in vivo anti-inflammatory effects of 4-methoxy-5- hydroxycanthin-6-one, a natural alkaloid from Picrasma quassioides

In the present study, we evaluated the anti-inflammatory effect of 4-methoxy-5- hydroxycanthin-6-one (CAN), a natural alkaloid isolated from Picrasma quassioides. CAN significantly inhibited the production of NO and the release of TNF-α induced by LPS in macrophage RAW 264.7. Western blot showed that CAN can downregulate the expression of iNOS protein. After oral administration, CAN (3, 9, and 27 mg/kg) reduced the development of carrageenan-induced paw edema and complete Freund's adjuvant (CFA)-induced chronic arthritis in rats. The observed results indicated that pre-treatment with CAN might be an effective therapeutic intervention against inflammatory diseases including chronic arthritis.

Anti-inflammatory activity of ethanol extract from Geranium sibiricum Linne

ETHNOPHARMACOLOGICAL RELEVANCE

Geranium sibiricum (Geraniaceae) Linne (GSL) is used to heal various disorders of the diarrhea and the intestinal inflammation as an herbal agent in East Asia.

AIMS OF THE STUDY

The purpose of the present study is to determine whether the ethanol (EtOH) extract of GSL regulates the inflammatory reaction stimulated by phorbol-12-myristate 13-acetate plus calcium ionophore A23187 (PMACI) in human mast cells (HMC-1).

MATERIALS AND METHODS

Western blot was used for activation of mitogen activated protein kinase (MAPK), transcription factors, induced nitric oxide synthase (iNOS), and cyclooxygenase (COX)-2 proteins. EMSA was for DNA binding activity. RT-PCR was used for gene expression.

RESULTS

EtOH extract of GSL (EGS) inhibits the expression of extracellular signal-regulated kinase (ERK), one of a MAPK, nuclear transcription factors involving nuclear factor (NF)-kappaB and Activator protein (AP)-1, COX-2 and iNOS. The results indicated that EGS decreased gene expression of interleukin (IL)-1beta and COX-2 in PMACI stimulated HMC-1 cells.

CONCLUSION

Hence, we speculate that EGS can use as a potent anti-inflammatory agent for inflammatory allergic diseases.

In vitro anti-inflammatory effects of arctigenin, a lignan from Arctium lappa L., through inhibition on iNOS pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Arctigenin, a bioactive constituent from dried seeds of Arctium lappa L. (Compositae) which has been widely used as a Traditional Chinese Medicine for dispelling wind and heat included in Chinese Pharmacophere, was found to exhibit anti-inflammatory activities but its molecular mechanism remains unknown yet.

AIM OF THE STUDY

To investigate the anti-inflammatory mechanism of arctigenin.

MATERIALS AND METHODS

Cultured macrophage RAW 264.7 cells and THP-1 cells were used for the experiments. Griess assay was used to evaluate the inhibitory effect of arctigenin on the overproduction of nitric oxide (NO). ELISA was used to determine the level of pro-inflammatory cytokines including tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6). The inhibitory effect on the enzymatic activity of cyclooxygenase-2 (COX-2) was tested by colorimetric method. Western blot was used to detect the expression of inducible nitric oxide synthase (iNOS) and COX-2.

RESULTS

Arctigenin suppressed lipopolysaccharide (LPS)-stimulated NO production and pro-inflammatory cytokines secretion, including TNF-alpha and IL-6 in a dose-dependent manner. Arctigenin also strongly inhibited the expression of iNOS and iNOS enzymatic activity, whereas the expression of COX-2 and COX-2 enzymatic activity were not affected by arctigenin.

CONCLUSIONS

These results indicated that potent inhibition on NO, TNF-alpha and IL-6, but not COX-2 expression and COX-2 activity, might constitute the anti-inflammatory mechanism of arctigenin. Arctigenin suppressed the overproduction of NO through down-regulation of iNOS expression and iNOS enzymatic activity in LPS-stimulated macrophage.

Nitric oxide initiates progression of human melanoma via a feedback loop mediated by apurinic/apyrimidinic endonuclease-1/redox factor-1, which is inhibited by resveratrol

It is well recognized that nitric oxide (NO) is involved in tumor progression, including melanoma. Measurement of proliferative and metastatic capacity by MTS and Matrigel invasion assays, respectively, was done and showed that NO-treated melanoma cells exhibited a higher capacity compared with control, especially metastatic Lu1205 cells. Apurinic/apyrimidinic endonuclease-1/redox factor-1 (APE/Ref-1) is a multifunctional protein and its role in tumor biology has attracted considerable attention. To determine whether APE/Ref-1 plays a role in mediating NO stimulation of melanoma progression, we investigated the effect of DETA/NO on levels of APE/Ref-1 and related downstream targets [activator protein-1 (AP-1)/JunD, matrix metalloproteinase-1 (MMP-1), Bcl-2, and inducible nitric oxide synthase (iNOS)] by Western blot and reverse transcription-PCR analysis. Following DETA/NO treatment, APE/Ref-1 and other downstream molecules were induced. Knockdown of APE/Ref-1 or AP-1/JunD by specific small interfering RNA markedly reversed the induction by NO stress of target proteins. These results present evidence for the existence of a functional feedback loop contributing to progression and metastasis of melanoma cells. Resveratrol has been shown to be an APE/Ref-1 inhibitor and significant decreases in AP-1/JunD, MMP-1, Bcl-2, and iNOS protein levels occurred after exposure to resveratrol. This phenolic antioxidant may be an appropriate choice for combining with other compounds that develop resistance by up-regulation of these molecules.

Dual roles of NF-kappaB in cell survival and implications of NF-kappaB inhibitors in neuroprotective therapy

NF-kappaB is a well-characterized transcription factor with multiple physiological and pathological functions. NF-kappaB plays important roles in the development and maturation of lymphoids, regulation of immune and inflammatory response, and cell death and survival. The influence of NF-kappaB on cell survival could be protective or destructive, depending on types, developmental stages of cells, and pathological conditions. The complexity of NF-kappaB in cell death and survival derives from its multiple roles in regulating the expression of a broad array of genes involved in promoting cell death and survival. The activation of NF-kappaB has been found in many neurological disorders, but its actual roles in pathogenesis are still being debated. Many compounds with neuroprotective actions are strongly associated with the inhibition of NF-kappaB, leading to speculation that blocking the pathological activation of NF-kappaB could offer neuroprotective effects in certain neurodegenerative conditions. This paper reviews the recent developments in understanding the dual roles of NF-kappaB in cell death and survival and explores its possible usefulness in treating neurological diseases. This paper will summarize the genes regulated by NF-kappaB that are involved in cell death and survival to elucidate why NF-kappaB promotes cell survival in some conditions while facilitating cell death in other conditions. This paper will also focus on the effects of various NF-kappaB inhibitors on neuroprotection in certain pathological conditions to speculate if NF-kappaB is a potential target for neuroprotective therapy.