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Anti-inflammatory effects of adenosine N1-oxide.

Kohno K, Ohashi E, Sano O, Kusano H, Kunikata T, Arai N, Hanaya T, Kawata T, Nishimoto T, Fukuda S - J Inflamm (Lond) (2015)

Bottom Line: Here, we examined adenosine N1-oxide (ANO), which is found in royal jelly.We found that it is refractory to adenosine deaminase-mediated conversion to inosine.Reflecting its potent anti-inflammatory effects in vitro, intravenous administration of ANO significantly reduced lethality of LPS-induced endotoxin shock.

View Article: PubMed Central - PubMed

Affiliation: Core Technology Division, Research and Development Center, Hayashibara Co., Ltd, Okayama, Japan.

ABSTRACT

Background: Adenosine is a potent endogenous anti-inflammatory and immunoregulatory molecule. Despite its promise, adenosine's extremely short half-life in blood limits its clinical application. Here, we examined adenosine N1-oxide (ANO), which is found in royal jelly. ANO is an oxidized product of adenosine at the N1 position of the adenine base moiety. We found that it is refractory to adenosine deaminase-mediated conversion to inosine. We further examined the anti-inflammatory activities of ANO in vitro and in vivo.

Methods: The effect of ANO on pro-inflammatory cytokine secretion was examined in mouse peritoneal macrophages and the human monocytic cell line THP-1, and compared with that of adenosine, synthetic adenosine receptor (AR)-selective agonists and dipotassium glycyrrhizate (GK2). The anti-inflammatory activity of ANO in vivo was examined in an LPS-induced endotoxin shock model in mice.

Results: ANO inhibited secretion of inflammatory mediators at much lower concentrations than adenosine and GK2 when used with peritoneal macrophages and THP-1 cells that were stimulated by LPS plus IFN-γ. The potent anti-inflammatory activity of ANO could not be solely accounted for by its refractoriness to adenosine deaminase. ANO was superior to the synthetic A1 AR-selective agonist, 2-chloro-N(6)-cyclopentyladenosine (CCPA), A2A AR-selective agonist, 2-[p-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamideadenosine hydrochloride (CGS21680), and A3 AR-selective agonist, N(6)-(3-iodobenzyl)adenosine-5'-N-methyluronamide (IB-MECA), in suppressing the secretion of a broad spectrum of pro-inflammatory cytokines by peritoneal macrophages. The capacities of ANO to inhibit pro-inflammatory cytokine production by THP-1 cells were comparable with those of CCPA and IB-MECA. Reflecting its potent anti-inflammatory effects in vitro, intravenous administration of ANO significantly reduced lethality of LPS-induced endotoxin shock. A significant increase in survival rate was also observed by oral administration of ANO. Mechanistic analysis suggested that the up-regulation of the anti-inflammatory transcription factor c-Fos was, at least in part, involved in the ANO-induced suppression of pro-inflammatory cytokine secretion.

Conclusions: Our data suggest that ANO, a naturally occurring molecule that is structurally close to adenosine but is functionally more potent, presents potential strategies for the treatment of inflammatory disorders.

No MeSH data available.


Related in: MedlinePlus

Levels of pro-inflammatory and anti-inflammatory cytokines in the sera of endotoxemic mice. ANO was administered intravenously as described in Figure 7A. Blood samples were collected from the abdominal aorta 2 h after LPS injection. Serum levels of TNF-α (A), IL-6 (B), IL-12 (C) and IL-10 (D) were measured by ELISA. Values represent the means ± S.D. of six mice in each group. Results are representative of two separate experiments with similar results. *p < 0.05; **p < 0.01, significantly different when compared with vehicle control.
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Fig8: Levels of pro-inflammatory and anti-inflammatory cytokines in the sera of endotoxemic mice. ANO was administered intravenously as described in Figure 7A. Blood samples were collected from the abdominal aorta 2 h after LPS injection. Serum levels of TNF-α (A), IL-6 (B), IL-12 (C) and IL-10 (D) were measured by ELISA. Values represent the means ± S.D. of six mice in each group. Results are representative of two separate experiments with similar results. *p < 0.05; **p < 0.01, significantly different when compared with vehicle control.

Mentions: Since excessive production of pro-inflammatory cytokines plays a critical role in animal models of septic shock [25], we measured serum levels of pro-inflammatory and anti-inflammatory cytokines 2 h after LPS administration. In accordance with prolongation of survival, serum levels of pro-inflammatory cytokines were significantly decreased in a dose-dependent manner by intravenous ANO administration (Figure 8A - C). In particular, serum TNF-α levels were decreased by 94% at 135 mg/kg of ANO administration (Figure 8A). With regard to anti-inflammatory cytokine IL-10, it was below detection in the sera of mice injected intravenously with PBS followed by intraperitoneal LPS injection (Figure 8D). However, when ANO was administered intravenously just before LPS injection, serum IL-10 levels were up-regulated and 14–19 ng/mL of IL-10 were detected.Figure 8


Anti-inflammatory effects of adenosine N1-oxide.

Kohno K, Ohashi E, Sano O, Kusano H, Kunikata T, Arai N, Hanaya T, Kawata T, Nishimoto T, Fukuda S - J Inflamm (Lond) (2015)

Levels of pro-inflammatory and anti-inflammatory cytokines in the sera of endotoxemic mice. ANO was administered intravenously as described in Figure 7A. Blood samples were collected from the abdominal aorta 2 h after LPS injection. Serum levels of TNF-α (A), IL-6 (B), IL-12 (C) and IL-10 (D) were measured by ELISA. Values represent the means ± S.D. of six mice in each group. Results are representative of two separate experiments with similar results. *p < 0.05; **p < 0.01, significantly different when compared with vehicle control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4308844&req=5

Fig8: Levels of pro-inflammatory and anti-inflammatory cytokines in the sera of endotoxemic mice. ANO was administered intravenously as described in Figure 7A. Blood samples were collected from the abdominal aorta 2 h after LPS injection. Serum levels of TNF-α (A), IL-6 (B), IL-12 (C) and IL-10 (D) were measured by ELISA. Values represent the means ± S.D. of six mice in each group. Results are representative of two separate experiments with similar results. *p < 0.05; **p < 0.01, significantly different when compared with vehicle control.
Mentions: Since excessive production of pro-inflammatory cytokines plays a critical role in animal models of septic shock [25], we measured serum levels of pro-inflammatory and anti-inflammatory cytokines 2 h after LPS administration. In accordance with prolongation of survival, serum levels of pro-inflammatory cytokines were significantly decreased in a dose-dependent manner by intravenous ANO administration (Figure 8A - C). In particular, serum TNF-α levels were decreased by 94% at 135 mg/kg of ANO administration (Figure 8A). With regard to anti-inflammatory cytokine IL-10, it was below detection in the sera of mice injected intravenously with PBS followed by intraperitoneal LPS injection (Figure 8D). However, when ANO was administered intravenously just before LPS injection, serum IL-10 levels were up-regulated and 14–19 ng/mL of IL-10 were detected.Figure 8

Bottom Line: Here, we examined adenosine N1-oxide (ANO), which is found in royal jelly.We found that it is refractory to adenosine deaminase-mediated conversion to inosine.Reflecting its potent anti-inflammatory effects in vitro, intravenous administration of ANO significantly reduced lethality of LPS-induced endotoxin shock.

View Article: PubMed Central - PubMed

Affiliation: Core Technology Division, Research and Development Center, Hayashibara Co., Ltd, Okayama, Japan.

ABSTRACT

Background: Adenosine is a potent endogenous anti-inflammatory and immunoregulatory molecule. Despite its promise, adenosine's extremely short half-life in blood limits its clinical application. Here, we examined adenosine N1-oxide (ANO), which is found in royal jelly. ANO is an oxidized product of adenosine at the N1 position of the adenine base moiety. We found that it is refractory to adenosine deaminase-mediated conversion to inosine. We further examined the anti-inflammatory activities of ANO in vitro and in vivo.

Methods: The effect of ANO on pro-inflammatory cytokine secretion was examined in mouse peritoneal macrophages and the human monocytic cell line THP-1, and compared with that of adenosine, synthetic adenosine receptor (AR)-selective agonists and dipotassium glycyrrhizate (GK2). The anti-inflammatory activity of ANO in vivo was examined in an LPS-induced endotoxin shock model in mice.

Results: ANO inhibited secretion of inflammatory mediators at much lower concentrations than adenosine and GK2 when used with peritoneal macrophages and THP-1 cells that were stimulated by LPS plus IFN-γ. The potent anti-inflammatory activity of ANO could not be solely accounted for by its refractoriness to adenosine deaminase. ANO was superior to the synthetic A1 AR-selective agonist, 2-chloro-N(6)-cyclopentyladenosine (CCPA), A2A AR-selective agonist, 2-[p-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamideadenosine hydrochloride (CGS21680), and A3 AR-selective agonist, N(6)-(3-iodobenzyl)adenosine-5'-N-methyluronamide (IB-MECA), in suppressing the secretion of a broad spectrum of pro-inflammatory cytokines by peritoneal macrophages. The capacities of ANO to inhibit pro-inflammatory cytokine production by THP-1 cells were comparable with those of CCPA and IB-MECA. Reflecting its potent anti-inflammatory effects in vitro, intravenous administration of ANO significantly reduced lethality of LPS-induced endotoxin shock. A significant increase in survival rate was also observed by oral administration of ANO. Mechanistic analysis suggested that the up-regulation of the anti-inflammatory transcription factor c-Fos was, at least in part, involved in the ANO-induced suppression of pro-inflammatory cytokine secretion.

Conclusions: Our data suggest that ANO, a naturally occurring molecule that is structurally close to adenosine but is functionally more potent, presents potential strategies for the treatment of inflammatory disorders.

No MeSH data available.


Related in: MedlinePlus