Modulation of murine macrophage function by methamphetamine

The abuse of methamphetamine (MA) is an increasingly growing problem globally and produces serious side effects. In the present study, the immunomodulating effects of MA were examined on murine peritoneal macrophages after MA (5 mg/kg body weight) was administered daily orally for 2 wk. When purified macrophages were stimulated with lipopolysaccharide (LPS), the tumoricidal activity induced by LPS was significantly suppressed by MA. MA also inhibited poly I:C-induced antiviral activity in macrophages and decreased the number of peritoneal macrophages. FACS analysis showed that the expression of CD14 was markedly decreased by MA in LPS-stimulated macrophages. The production of nitric oxide (NO) and tumor necrosis factor (TNF)-alpha: which are known to be major effector molecules in macrophage-mediated cytotoxicity, was decreased by MA. MA produced a significant effect on phagocytosis and interleukin-1 (IL-1) and IL-6 at 14 d. In addition, the level of hydrogen peroxide (H2O2) was not altered by MA. Taken together, these data indicate that MA has a differential immunomodulating effect on macrophage secretory and cellular activities.     

Stereocalpin A inhibits the expression of adhesion molecules in activated vascular smooth muscle cells

Up-regulation of cell adhesion molecules on vascular smooth muscle cells (VSMCs) and leukocyte recruitment to the vascular wall contribute to vascular inflammation and atherosclerosis. Stereocalpin A, a chemical compound of the Antarctic lichen Ramalina terebarata, displays tumoricidal activity against several different tumor cell types. However, other biological activities of stereocalpin A and its molecular mechanisms remain unknown. In this study, our work is directed toward studying the in vitro effects of stereocalpin A on the ability to suppress the expression of adhesion molecules induced by TNF-α in vascular smooth muscle cells. Pretreatment of VSMCs for 2h with stereocalpin A at nontoxic concentrations of 0.1-10 μg/ml inhibited TNF-α-induced adhesion of THP-1 monocytic cells and expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Stereocalpin A reduced TNF-α-induced production of intracellular reactive oxygen species (ROS) and phosphorylation of p38, ERK, JNK and Akt. Stereocalpin A also inhibited NK-κB activation induced by TNF-α. Moreover, stereocalpin A inhibited TNF-α-induced ΙκΒ kinase activation, subsequent degradation of ΙκΒα, and nuclear translocation of NF-κB. Hence, we describe a new anti-inflammatory activity and mechanism of stereocalpin A, owing to the negative regulation of TNF-α-induced adhesion molecule and MCP-1 expression, monocyte adhesion and ROS production in vascular smooth muscle cells. These results suggest that stereocalpin A has the potential to exert a protective effect by modulating inflammation within the atherosclerotic lesion.     

Water extract of processed Hydrangea macrophylla (Thunb.) Ser. leaf attenuates the expression of pro-inflammatory mediators by suppressing Akt-mediated NF-κB activation

Although Hydrangea macrophylla is native to Northeast Asia and widely cultivated in many parts of the world, no studies on its anti-inflammatory effects have been reported. In this study, we evaluated the anti-inflammatory effect of a water extract of processed H. macrophylla leaf (WH) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. WH inhibited the expression of LPS-stimulated pro-inflammatory mediators such as nitric oxide (NO), prostaglandin E₂ (PGE₂), and tumor necrosis factor-α (TNF-α), as well as their regulatory genes inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and TNF-α without any accompanying cytotoxicity. Moreover, WH significantly suppressed the LPS-induced DNA-binding activity of nuclear factor-κB (NF-κB), as well as the nuclear translocation of the NF-κB subunits, p65 and p50 by suppressing of IκBα phosphorylation and degradation. WH also increased Akt dephosphorylation, leading to the suppression of the DNA-binding activity of NF-κB in LPS-stimulated RAW264.7 macrophage cells. Our results indicate that WH downregulates the expression of pro-inflammatory mediators such as NO, PGE₂, and TNF-α by suppressing the Akt-mediated NF-κB activity in LPS-stimulated RAW264.7 macrophage cells.     

Inhibition of prostaglandin production by a structurally-optimized flavonoid derivative, 2',4',7-trimethoxyflavone and cellular action mechanism

Flavonoids possess anti-inflammatory activity in vitro and in vivo. In order to find the anti-inflammatory flavone derivatives having optimum chemical structures, various flavones were previously synthesized and evaluated for their inhibitory activity of prostaglandin E(2) (PGE(2)) production from lipopolysaccharide (LPS)-treated mouse macrophage cell line, RAW 264.7 cells. Through this screening procedure, 2',4',7-trimethoxyflavone (TMF) was selected for further pharmacological study. From the present investigation, it was found that TMF potently inhibited PGE(2) production from LPS-treated RAW cells with an IC(50) of 0.48 microM, compared to the IC(50) values of 0.07 and 1.09 microM for NS-398 and wogonin. TMF, however, did not inhibit cyclooxygenase-2 (COX-2) activity or COX-2 expression level. Instead, TMF was proved to be a phospholipase A(2) (PLA(2)) inhibitor. The IC(50) values of TMF against secretory PLA(2)-IIA (sPLA(2)-IIA) and cytosolic PLA(2) (cPLA(2)) were 70.5 and 70.4 microM, respectively. At doses of 10-250 microg/ear, TMF also showed in vivo anti-inflammatory activity by topical application against mouse croton oil-induced ear edema assay, suggesting a potential for new anti-inflammatory agent.     

Sulforaphane suppresses vascular adhesion molecule-1 expression in TNF-α-stimulated mouse vascular smooth muscle cells: involvement of the MAPK, NF-κB and AP-1 signaling pathways

Atherosclerosis is a long-term inflammatory disease of the arterial wall. Increased expression of the cell adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) is associated with increased proliferation of vascular smooth muscle cells (VSMCs), leading to increased neointima or atherosclerotic lesion formation. Therefore, the functional inhibition of adhesion molecules could be a critical therapeutic target of inflammatory disease. In the present study, we investigate the effect of sulforaphane on the expression of VCAM-1 induced by TNF-α in cultured mouse vascular smooth muscle cell lines. Pretreatment of VSMCs for 2h with sulforaphane (1-5μg/ml) dose-dependently inhibited TNF-α-induced adhesion of THP-1 monocytic cells and protein expression of VCAM-1. Sulforaphane also suppressed TNF-α-induced production of intracellular reactive oxygen species (ROS) and activation of p38, ERK and JNK. Furthermore, sulforaphane inhibited NK-κB and AP-1 activation induced by TNF-α. Sulforaphane inhibited TNF-α-induced ΙκΒ kinase activation, subsequent degradation of ΙκΒα and nuclear translocation of p65 NF-κB and decreased c-Jun and c-Fos protein level. This study suggests that sulforaphane inhibits the adhesive capacity of VSMC and downregulates the TNF-α-mediated induction of VCAM-1 in VSMC by inhibiting the MAPK, NF-κB and AP-1 signaling pathways and intracellular ROS production. Thus, sulforaphane may have beneficial effects to suppress inflammation within the atherosclerotic lesion.     

Suppression of adhesion molecule expression by phenanthrene-containing extract of bulbils of Chinese Yam in vascular smooth muscle cells through inhibition of MAPK,Akt and NF-κB

Atherosclerosis is a chronic inflammatory disease associated with increased expression of adhesion molecules in vascular smooth muscle cells (VSMCs). The objective of this study was to examine the in vitro effects of extract from aerial Bulbil of Dioscorea batatas Decne (Db-Ex) on the ability to suppress the expression of adhesion molecules induced by TNF-α. We also identified bioactive components from a methanol extract. VSMCs pre-exposed to Db-Ex (10–100 μg/ml) were stimulated with TNF-α (10 ng/ml). Preincubation of VSMCs for 2 h with Db-Ex dose-dependently inhibited TNF-α-induced adhesion of THP-1 monocytic cells and mRNA and protein expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Db-Ex treatment decreased ROS production and the amount of phosphorylated form of p38, ERK, JNK and Akt in TNF-α-stimulated cells, suggesting that Db-Ex inhibits adhesion molecule expression possibly through MAPK and Akt regulation. Db-Ex also suppressed TNF-α-activation NK-κB. This effect was mediated through degradation of IκBα and nuclear translocation of the p65 subunit of NF-κB. These results suggest that Db-Ex inhibits monocyte adhesion and the TNF-α-mediated induction of adhesion molecules in VSMC by downregulating the MAPK/Akt/NF-κB signaling pathway, which may explain the ability of Db-Ex to suppress inflammation within the atherosclerotic lesion.     

5-Lipoxygenase Inhibition of the Fructus of Foeniculum vulgare and Its Constituents

The fruits of Foeniculum vulgare (Foeniculi Fructus) have been widely used in Chinese medicine as an antiemetic, ameliorating stomach ailments and as an analgesic. In order to establish its potential for antiallergic use, inhibitory actions of the fruiton 5-lipoxgenase (5-LOX) and β-hexosaminidase release were evaluated. The 70% ethanol extract of this plant material (FR) considerably inhibited 5-LOX-catalyzed leukotriene production from {"type":"entrez-nucleotide","attrs":{"text":"A23187","term_id":"833253"}}A23187-induced rat basophilic leukemia (RBL)-1 cells. The IC₅₀ was 3.2 μg/ml. From this extract, 12 major compounds including sabinene, fenchone, γ-terpinene, α-pinene, limonene, p-anisylacetone, p-anisylaldehyde, estragole (4-allylanisole), trans-anethole, scopoletin, bergapten and umbelliferone were isolated. And it was found that several terpene derivatives including γ-terpinene and fenchone as well as phenylpropanoid, trans-anethole, showed considerable inhibitory action of 5-LOX. In particular, the IC₅₀ of trans-anethole was 51.6 μ M. In contrast, FR and the isolated compounds did not show considerable inhibitory activity on the degranulation reaction of β-hexosaminidase release from antigen-treated RBL-2H3 cells. Against arachidonic acid-induced ear edema in mice, FR and trans-anethole showed significant inhibition by oral administration at doses of 100-400 mg/kg. In conclusion, FR and several major constituents are 5-LOX inhibitors and they may have potential for treating 5-LOX-related disorders.     

Causal Effects of Homocysteine,Folate, and Cobalamin on Kidney Function: A Mendelian Randomization Study

Blood homocysteine level and related vitamin levels are associated with various health outcomes. We aimed to assess causal effects of blood homocysteine, folate, and cobalamin on kidney function in the general population by performing Mendelian randomization (MR) analysis. Genetic instruments for blood homocysteine, folate, and cobalamin levels were introduced from a previous genome-wide association (GWAS) meta-analysis of European individuals. Summary-level MR analysis was performed for the estimated glomerular filtration rate (eGFR) from the CKDGen consortium GWAS that included 567,460 European ancestry individuals. For replication, allele-score-based MR was performed with an independent U.K. Biobank cohort of 337,138 individuals of white British ancestry. In summary-level MR for the CKDGen data, high genetically predicted homocysteine levels were significantly associated with low eGFR (per 1 standard deviation, beta for eGFR change −0.95 (−1.21, −0.69) %), supported by pleiotropy-robust MR sensitivity analysis. Genetically predicted high folate levels were significantly associated with high eGFR change (0.86 (0.30, 1.42) %); however, causal estimates from cobalamin were nonsignificant (−0.11 (−0.33, 0.11) %). In the U.K. Biobank data, the results were consistently identified. Therefore, a high blood homocysteine level causally decreases eGFR. Future trials with appropriate homocysteine-lowering interventions may be helpful for the primary prevention of kidney function impairment.     

Inhibition of ICAM-1 expression by garlic component, allicin, in gamma-irradiated human vascular endothelial cells via downregulation of the JNK signaling pathway

Ionizing radiation used in cancer therapy frequently exerts damaging effects on normal tissues and induces a complex response including inflammation. Since the upregulation of adhesion molecules on endothelial cell surface has been known to be associated with inflammation and our previous data showed that irradiation enhanced adhesion molecules expression, interfering with the expression of adhesion molecules may be an important therapeutic target of inflammatory diseases. We examined the effect of allicin, a major component of garlic, on the induction of intercellular adhesion molecule-1 (ICAM-1) by gamma-irradiation (gamma IR) and the mechanisms of its effect in gamma-irradiated human umbilical vein endothelial cells (HUVECs). HUVECs were pretreated for 20 h with allicin (0.01-1 micro g/ml) and then exposed to 8 Gy radiation. Allicin significantly inhibited gamma IR-induced surface expression of ICAM-1 and ICAM mRNA in a dose-dependent manner. In addition, pretreatment with allicin resulted in the decrease of AP-1 activation and phosphorylation of the c-Jun NH2-terminal kinase (JNK) induced by gamma IR. These results suggest that allicin downregulates gamma IR-induced ICAM-1 expression via inhibition of both AP-1 activation and the JNK pathway and may be considered in therapeutic strategies for the management of patients treated with radiation therapy.     

Anti-tumor metastatic activity of beta-glucan purified from mutated Saccharomyces cerevisiae

The beta-glucans isolated from Saccharomyces cerevisiae (S. cerevisiae) enhance the innate immune system, but there is little evidence for its antitumor activity. To examine the antitumor and immunostimulating activities of beta-glucan (IS-2) purified from mutated S. cerevisiae, we made an experiment on innate immune response against metastasis of cancer cells by comparing with the beta-glucan from wild-type S. cerevisiae. In experimental lung metastasis of colon 26-M3.1 carcinoma or B16-BL6 melanoma cells, prophylactic administration of beta-glucan purified from mutated S. cerevisiae significantly inhibited lung metastasis in a dose-dependent manner. Furthermore, therapeutic administration of IS-2 also significantly inhibited the colon 26-M3.1 cell growth in mice. In an assay of liver and spleen metastasis produced by i.v. inoculation of L5178Y-ML25 lymphoma cells, IS-2 also significantly inhibited metastasis in CDF1 mice. Furthermore, pretreatment with IS-2 two days before tumor inoculation significantly prolonged the survival time of tumor-bearing mice. In an in vitro cytotoxicity analysis, IS-2 (up to 100 microg/ml) did not affect the growth of colon 26-M3.1 cells. In contrast, IS-2 enhanced splenocyte proliferating activity in a dose-dependent manner. Peritoneal macrophages stimulated with IS-2 produced various cytokines, such as IL-1beta, IFN-gamma, and IL-12. In addition, treatment with IS-2 (20 microg/mouse) induced tumoricidal activity of peritoneal macrophages against colon 26-M3.1 cells. In an assay for natural killer (NK) cell activity, IS-2 (20 microg/mouse, i.v.) significantly augmented NK cytotoxicity against Yac-1 tumor cells at 2 days after IS-2 treatment. The depletion of NK cells by injection of rabbit anti-asialo GM1 serum abolished the inhibitory effect of IS-2 on lung metastasis of colon 26-M3.1 cells. These data suggest that IS-2 inhibits tumor metastasis via activation of macrophages and NK cells.