Obesity is consistently increasing in prevalence and can trigger insulin resistance and type 2 diabetes. Many lines of evidence have shown that macrophages play a major role in inflammation associated with obesity. This study was conducted to determine metformin, a widely prescribed drug for type 2 diabetes, would regulate inflammation through down-regulation of scavenger receptors in macrophages from obesity-induced type 2 diabetes. RAW 264.7 cells and peritoneal macrophages were stimulated with LPS to induce inflammation, and C57BL/6N mice were fed a high-fat diet to generate obesity-induced type 2 diabetes mice. Metformin reduced the production of NO, PGE2 and pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) through down-regulation of NF-κB translocation in macrophages in a dose-dependent manner. On the other hand, the protein expressions of anti-inflammatory cytokines, IL-4 and IL-10, were enhanced or maintained by metformin. Also, metformin suppressed secretion of TNF-α and reduced the protein and mRNA expression of TNF-α in obese mice as well as in macrophages. The expression of scavenger receptors, CD36 and SR-A, were attenuated by metformin in macrophages and obese mice. These results suggest that metformin may attenuate inflammatory responses by suppressing the production of TNF-α and the expressions of scavenger receptors.

BackgroundArctiin, isolated from Forsythia suspensa has been reported to have anti-inflammatory, anti-oxidant, antibacterial, and antiviral effects in vitro. However, there has been a lack of studies regarding its effects on immunological activity. The aim of this study is to investigate the anti-inflammatory potential and possible mechanisms of arctiin in LPS-induced macrophages.MethodsWe investigated the mRNA and protein levels of proinflammatory cytokines through RT-PCR and western blot analysis, followed by a FACS analysis for surface molecule changes.ResultsArctiin dose dependently decreased the production of NO and proinflammatory cytokines such as IL-1β, IL-6, TNF-α, and PGE2, and it reduced the gene and protein levels as determined by RT-PCR and western blot analysis, respectively. The expression of co-stimulatory molecules such as B7-1 and B7-2 were also inhibited by arctiin. Furthermore, the activation of the nuclear transcription factor, NF-κB in macrophages was inhibited by arctiin.ConclusionTaken together these results provide evidence of the bioactivity of arctiin in inflammatory diseases and suggest that arctiin may exert anti-inflammatory effect by inhibiting the pro-inflammatory mediators through the inactivation of NF-kB.

BackgroundIt has been recently noticed that type 2 diabetes (T2D), one of the most common metabolic diseases, causes a chronic low-grade inflammation and activation of the innate immune system that are closely involved in the pathogenesis of T2D. Cordyceps militaris, a traditional medicinal mushroom, produces a component compound, cordycepin (3'-deoxyadenosine). Cordycepin has been known to have many pharmacological activities including immunological stimulating, anti-cancer, and anti-infection activities. The molecular mechanisms of cordycepin in T2D are not clear. In the present study, we tested the role of cordycepin on the anti-diabetic effect and anti-inflammatory cascades in LPS-stimulated RAW 264.7 cells.MethodsWe confirmed the levels of diabetes regulating genes mRNA and protein of cytokines through RT-PCR and western blot analysis and followed by FACS analysis for the surface molecules.ResultsCordycepin inhibited the production of NO and pro-inflammatory cytokines such as IL-1β, IL-6, and TNF-α in LPS-activated macrophages via suppressing protein expression of pro-inflammatory mediators. T2D regulating genes such as 11β-HSD1 and PPARγ were decreased as well as expression of co-stimulatory molecules such as ICAM-1 and B7-1/-2 were also decreased with the increment of its concentration. In accordance with suppressed pro-inflammatory cytokine production lead to inhibition of diabetic regulating genes in activated macrophages. Cordycepin suppressed NF-κB activation in LPS-activated macrophages.ConclusionBased on these observations, cordycepin suppressed T2D regulating genes through the inactivation of NF-κB dependent inflammatory responses and suggesting that cordycepin will provide potential use as an immunomodulatory agent for treating immunological diseases.

BackgroundChronic low grade inflammation is closely linked to type II diabetes, obesity, and atherosclerosis. Macrophages play a key role in the regulation of pro- or anti-inflammatory actions at the lesion sites of disease. Components of cordyceps militaris, cordycepin and adenosine, have been used for the modulation of inflammatory diseases. The effects of cordycepin in the modulation of macrophages have yet to be elucidated. We investigated the effects of cordycepin and adenosine on the morphological changes of macrophages under the inflammatory condition of LPS and an anti-inflammatory condition involving high concentrations of adenosine.MethodsWe confirmed the mRNA levels of the M1/M2 cytokine genes through RT-PCR and morphological change.ResultsLPS-activated macrophages returned to their inactivated original shape, i.e., they looked like naïve macrophages, through the treatment with high concentrations of cordycepin (40 µg/ml). LPS and adenosine activated macrophages also returned to their original inactivated shapes after cordycepin treatment; however, at relatively higher levels of cordycepin than adenosine. This change did not occur with relatively low concentrations of cordycepin. Adenosine down-regulated the gene expression of M1 cytokines (IL-1β, TNF-α) and chemokines (CX3CR1, RANTES), as well as cordycepin. Additionally, M2 cytokines (IL-10, IL-1ra, TGF-β) were up-regulated by both cordycepin and adenosine.ConclusionBased on these observations, both cordycepin and adenosine regulated the phenotypic switch on macrophages and suggested that cordycepin and adenosine may potentially be used as immunomodulatory agents in the treatment of inflammatory disease.

BackgroundCordyceps militaris has been used in traditional medicine to treat numerous diseases and has been reported to possess both antitumor and immunomodulatory activities in vitro and in vivo. However, the pharmacological and biochemical mechanisms of Cordyceps militaris extract (CME) on macrophages have not been clearly elucidated. In the present study, we examined how CME induces the production of proinflammatory cytokines, transcription factor, and the expression of co-stimulatory molecules.MethodsWe confirmed the mRNA and protein levels of proinflammatory cytokines through RT-PCR and western blot analysis, followed by a FACS analysis for surface molecules.ResultsCME dose dependently increased the production of NO and proinflammatory cytokines such as IL-1β, IL-6, TNF-α, and PGE2, and it induced the protein levels of iNOS, COX-2, and proinflammatory cytokines in a concentration-dependent manner, as determined by western blot and RT-PCR analysis, respectively. The expression of co-stimulatory molecules such as ICAM-1, B7-1, and B7-2 was also enhanced by CME. Furthermore, the activation of the nuclear transcription factor, NF-κB in macrophages was stimulated by CME.ConclusionBased on these observations, CME increased proinflammatory cytokines through the activation of NF-κB, further suggesting that CME may prove useful as an immune-enhancing agent in the treatment of immunological disease.

BackgroundMetabolic disorders, including type II diabetes and obesity, present major health risks in industrialized countries. AMP-activated protein kinase (AMPK) has become the focus of a great deal of attention as a novel therapeutic target for the treatment of metabolic syndromes. In this study, we evaluated whether dietary aloe could reduce obesity-induced inflammation and adipogenesis.MethodsMale C57BL/6 obese mice fed a high-fat diet for 54 days received a supplement of aloe formula (PAG, ALS, Aloe QDM, and Aloe QDM complex) or pioglitazone (PGZ) and were compared with unsupplemented controls (high-fat diet; HFD) or mice fed a regular diet (RD). RT-PCR and western blot analysis were used to quantify the expression of obesity-induced inflammation.ResultsAloe QDM complex down-regulated fat size through suppressed expression of scavenger receptors on adipose tissue macrophages (ATMs) compared with HFD. Both white adipose tissue (WATs) and muscle exhibited increased AMPK activation through aloe supplementation, and in particular, the Aloe QDM complex. Obesity-induced inflammatory cytokines (IL-1β and -6) and HIF1α mRNA and protein were decreased markedly, as was macrophage infiltration by the Aloe QDM complex. Further, the Aloe QDM complex decreased the translocation of NF-κB p65 from the cytosol in the WAT.ConclusionDietary aloe formula reduced obesity-induced inflammatory responses by activation of AMPK in muscle and suppression of proinflammatory cytokines in the WAT. Additionally, the expression of scavenger receptors in the ATM and activation of AMPK in WAT led to reduction in the percent of body fat. Thus, we suggest that the effect of the Aloe QDM complex in the WAT and muscle are related to activation of AMPK and its use as a nutritional intervention against T2D and obesity-related inflammation.

BackgroundInsulin resistance is an integral feature of metabolic syndromes, including obesity, hyperglycemia, and hyperlipidemia. In this study, we evaluated whether the aloe component could reduce obesity-induced inflammation and the occurrence of metabolic disorders such as blood glucose and insulin resistance.MethodsMale C57BL/6 obese mice fed a high-fat diet for 54 days received a supplement of aloe formula (PAG, ALS, Aloe QDM, and Aloe QDM complex) or pioglitazone (PGZ) and were compared with unsupplemented controls (high-fat diet; HFD) or mice fed a regular diet (RD). RT-PCR and western blot analysis were used to quantify the expression of obesity-induced inflammation.ResultsAloe QDM lowered fasting blood glucose and plasma insulin compared with HFD. Obesity-induced inflammatory cytokine (IL-1β, -6, -12, TNF-α) and chemokine (CX3CL1, CCL5) mRNA and protein were decreased markedly, as was macrophage infiltration and hepatic triglycerides by Aloe QDM. At the same time, Aloe QDM decreased the mRNA and protein of PPARγ/LXRα and 11β-HSD1 both in the liver and WAT.ConclusionDietary aloe formula reduces obesity-induced glucose tolerance not only by suppressing inflammatory responses but also by inducing anti-inflammatory cytokines in the WAT and liver, both of which are important peripheral tissues affecting insulin resistance. The effect of Aloe QDM complex in the WAT and liver are related to its dual action on PPARγ and 11β-HSD1 expression and its use as a nutritional intervention against T2D and obesity-related inflammation is suggested.

Dioscoreae Rhizome (DR) has been used in traditional medicine to treat numerous diseases and is reported to have anti-diabetes and anti-tumor activities. To identify a bioactive traditional medicine with anti-inflammatory activity of a water extract of DR (EDR), we determined the mRNA and protein levels of proinflammatory cytokines in macrophages through RT-PCR and western blot analysis and performed a FACS analysis for measuring surface molecules. EDR dose-dependently decreased the production of NO and pro-inflammatory cytokines such as IL-1β, IL-6, TNF-α, and PGE2, as well as mRNA levels of iNOS, COX-2, and pro-inflammatory cytokines, as determined by western blot and RT-PCR analysis, respectively. The expression of co-stimulatory molecules such as B7-1 and B7-2 was also reduced by EDR. Furthermore, activation of the nuclear transcription factor, NF-κB, but not that of IL-4 and IL-10, in macrophages was inhibited by EDR. These results show that EDR decreased pro-inflammatory cytokines via inhibition of NF-κB-dependent inflammatory protein level, suggesting that EDR could be a useful immunomodulatory agent for treating immunological diseases.