Germinated brown rice (GBR, Orysa sartiva L.) has been reported to have anti-obesity and anti-inflammatory effects. However, the mechanisms underlying these effects in adipocytes are not fully understood. Therefore, this study was conducted to explore the anti-inflammatory mechanisms of GBR on lipopolysaccharide (LPS)-stimulated 3T3-L1 adipocytes. 3T3-L1 adipocytes were pretreated with GBR extracts (0-20 mg/mL) 1 h before LPS stimulation. The mRNA expression of adipokines and Toll-like receptor 4 (TLR4) were measured by RT-PCR. The protein expressions of TLR4- related molecules were detected by western blotting and nuclear factor-κB (NF-κB) activation was measured. Our results showed that GBR extract dose-dependently inhibited mRNA expression of LPS-induced tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1). GBR extract was found to inhibit LPS-induced mRNA expression of TLR4 and protein expression of both myeloid differentiation factor 88 (MyD88) and TNF receptorassociated factor 6 (TRAF6). Furthermore, GBR extract significantly inhibited extracellular receptor-activated kinase (ERK) phosphorylation and NF-κB activation. These results suggest that GBR extract has the anti-inflammatory effects on LPSinduced inflammation via inhibition of TLR4 signaling, includingthe ERK and NF-κB signaling pathways, in adipocytes.
Increased intracellular levels of Ca2+ are generally thought to negatively regulate lipolysis in mature adipocytes, whereas store-operated Ca2+ entry was recently reported to facilitate lipolysis and attenuate lipotoxicity by inducing lipophagy. Transient receptor potential mucolipin1 (TRPML1), a Ca2+-permeable non-selective cation channel, is mainly expressed on the lysosomal membrane and plays key roles in lysosomal homeostasis and membrane trafficking. However, the roles of TRPML1 in lipolysis remains unclear. In this study, we examined whether the channel function of TRPML1 induces lipolysis in mature adipocytes. We found that treatment of mature adipocytes with ML-SA1, a specific agonist of TRPML1, solely upregulated extracellular glycerol release, but not to the same extent as isoproterenol. In addition, knockdown of TRPML1 in mature adipocytes significantly reduced autophagic flux, regardless of ML-SA1 treatment. Our findings demonstrate that the channel function of TRPML1 partially contributes to lipid metabolism and autophagic membrane trafficking, suggesting that TRPML1, particularly the channel function of TRPML1, is as therapeutic target molecule for treating obesity.
Aloe-emodin (AE) is the major bioactive component in aloe and known to exhibit anti-inflammatory activities. However, it has not been elucidated whether its anti-inflammatory potency can contribute to the elimination of obesity. The aim of the current study is to investigate the effect of AE on toll-like receptor 4 (TLR4) pathways in the presence of lipopolysaccharide (LPS) in 3T3-L1 adipocytes. 3T3-L1 adipocytes were treated with AE (0-20 μM) for one hour, followed by LPS treatment for 30 min and then, adipokine mRNA expression levels were measured. Next, TLR4-related molecules were measured in LPS-stimulated 3T3-L1 adipocytes. AE significantly decreased the mRNA expression of the tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) in a dose-dependent manner. Moreover, AE suppressed TLR4 mRNA expression. Further study showed that AE could suppress the nuclear factor-κB (NF-κB) and phosphorylation of extracellular receptor-activated kinase (pERK). The results of this study suggest that AE directly inhibits TLR4/NF-κB/ERK signaling pathways and decreases the inflammatory response in adipocytes.
본 연구는 Sprague-Dawley 흰쥐 16마리를 이용하여 흰쥐 복강 및 피하지방 감소 후보 항체가 체중, in vivo 타장기 안전성 및 혈액성상 등 영양생리대사에 미치는 영향을 조사하고자 실시하였다. 무처리구(control), 비면역항체 처리구(NAb), 면양을 이용하여 기 개발된 흰쥐 복강(AAb) 및 피하지방 감소 후보항체(SAb)를 복강 주사하였을 때 주사 후 1주차에 SAb 처리구에서 사료 및 물 섭취량의 일시적인 감소가 나타났으나 그 이후에는 정상적으로 회복되는 것으로 보아 항체의 효과보다는 개체 차이에 기인하는 것으로 판단된다. 흰쥐 체중의 경우 항체 주사 처리 전․후 및 실험구 간 통계적인 유의차는 나타나지 않았다(p>0.05). SAb 처리구에서 나타난 주사 처리 후 1-2주 동안 일시적인 체중 감소 현상이 발생했으나, 통계적 유의성은 없었다(p>0.05). 후보 항체 주사 시 흰쥐 AAb 처리구는 control과 비교해서 생체 신장의 무게가 유의적으로 낮은 것으로 나타났다(p<0.05). 하지만, NAb 처리구의 신장 무게 역시 유의적인 감소를 보여(p<0.05) 결국 AAb 처리구의 신장 무게 감소는 주사에 의한 스트레스 또는 개체 간의 변이 때문인 것으로 생각된다. 신장을 제외하고는 후보 항체에 의한 주요 장기들(심장, 간장, 폐 및 비장)의 무게에는 실험구 간 유의적인 차이가 나타나지 않았다(p>0.05). 후보 항체에 의해 혈중 glucose, triglyceride 및 total cholesterol 농도에는 실험구 간 유의적인 변화가 나타나지 않았으며(p>0.05), 각 혈액대사물질의 농도는 일반적인 수준으로 나타났다. 이상의 결과를 볼 때, 본 연구에서 이용된 흰쥐AAb 및 SAb는 in vivo 영양생리대사에 부정적 영향을 미치지 않는 안전한 항체로 판단된다.
Resveratrol (RVT) and epigallocatechin gallate (EGCG) individually inhibit adipogenesis in 3T3-L1 adipocytes. The objective was to examine the possibility of interaction between RVT and EGCG, resulting in enhanced inhibition of adipogenesis in 3T3-L1 adipocytes. Preadipocytes were treated with RVT and EGCG individually at 6.25 or 25μM (RVT6.25 or RVT25) and 12.5 or 50μM (EGCG12.5 or EGCG50) and in combination (RVT6.25 + EGCG12.5 and RVT25 + EGCG50). RVT25 as an individual compound decreased lipid accumulation in 3T3-L1 adipocytes by 24%, and RVT25 + EGCG50 further decreased lipid accumulation by 77%. In addition, exposure of 3T3-L1 adipocytes to RVT6.25 + EGCG12.5 and RVT25 + EGCG50 combinations resulted in an enhanced increase of adiponectin release and inhibition of leptin release. Quantitative analysis revealed that the combination of tested materials (RVT6.25 + EGCG12.5 and RVT25 + EGCG50) decreased the expression levels of C/EBPα, PPARγ2, and aP2. These results indicate that the combined treatments with RVT and EGCG produce synergistic effects on inhibiting adipogenesis in 3T3-L1 adipocytes. The overall results suggested that the combining RVT and EGCG might be more capable of exerting antiobesity effects than each individual compound by itself.
Background : Ephedra Sinica has been used to treat obesity in Korean medicine and brown adipocytes also have potential in obesity treatment. Recently, p53 is considered as one of transcriptional regulators regarding thermogenesis of brown adipocytes. Methods and Results : E. Sinica extraction was made with DW and brown preadipocytes were differentiated with adipogenic reagents by incubating for 6 days in the absence or presence of E. Sinica extraction 5 ㎍/㎖ and 10 ㎍/㎖, non-cytotoxic concentration determined by MTT assay. Studies were conducted to see whether E. Sinica modulates the expression of thermogenic and adipogenic genes by qPCR and Western blot. Results showed that E. Sinica significantly activated thermogenesis of brown adipocytes by increasing the mRNA expressions of Uncoupling Protein 1 (UCP1), Cell Death-inducing DNA Fragmentation Factor Alpha-like Effector A (CIDEA), Interferon Regulatory Factor 4 (IRF4) and Beta-3 Adrenergic Receptor (ADRB3). However, major adipogenic genes such as Peroxisome Proliferator-activated Receptor Gamma (PPARλ) and PR Domain Containing 16 (PRDM16), showed no significant differences. In addition, the expression level of p53 was decreased by E. Sinica. Conclusion : It is suggest that E. Sinica stimulates the thermogenesis of brown adipocytes via p53 inhibition.
Obesity is characterized by a state of chronic low-grade inflammation and insulin resistance, which are aggravated by the interaction between hypertrophic adipocytes and macrophages. In this study, we investigated the effects of tangeretin on inflammatory changes and glucose uptake in a coculture of hypertrophic adipocytes and macrophages. Tangeretin decreased nitric oxide production and the expression of interleukin (IL)-6, IL-1β, tumor necrosis factor-α, inducible nitric oxide synthase, and cyclooxygenase-2 in a coculture of 3T3-L1 adipocytes and RAW 264.7 cells. Tangeretin also increased glucose uptake in the coculture system, but did not affect the phosphorylation of insulin receptor substrate (IRS) and Akt. These results suggest that tangeretin improves insulin resistance by attenuating obesity-induced inflammation in adipose tissue.
Recently, NADPH oxidase 4 (NOX4)-mediated generation of intracellular reactive oxygen species (ROS) was proposed to accelerate adipogenesis of 3T3-L1 cell. We have previously shown that Cheonnyuncho (Opuntia humifusa) extract significantly inhibited adipocyte differentiation via downregulation of PPARγ (peroxisome proliferator-activated receptor gamma) gene expression. In this study, we focused on the molecular mechanism(s) of NOX4, G6PDH (glucose-6-phosphate dehydrogenase) and antioxidant enzymes in anti-oxidative activities of 3T3-L1 adipocytes. Our results indicate that Cheonnyuncho extracts markedly inhibits ROS production during adipogenesis in 3T3-L1 cells. Cheonnyuncho extracts suppressed the mRNA expression of the pro-oxidant enzyme such as NOX4 and theNADPH-producing G6PDH enzyme. In addition, treatment with Cheonnyuncho extract was found to upregulate mRNA levels of antioxidant enzymes such as Mn-SOD (manganese-superoxide dismutase), Cu/Zn-SOD (copper/zinc-SOD), glutathione peroxidase (GPx), glutathion reductase (GR), and catalase, all of which are important for endogenous antioxidant responses. These data suggest that Cheonnyuncho extract may be effective in preventing the rise of oxidative stress during adipocyte differentiation through mechanism(s) that involves direct down regulation of NOX4 and G6PDH gene expression or via upregulation of endogenous antioxidant responses.
꾸지뽕잎의 물 및 70% 에탄올 추출물에 대한 세포의 독성 및 지방생성에 미치는 영향과 DNJ 함량과 rutin 함량을 측정하였다. Cell viability test에서 꾸지뽕잎 추출물 0.5-5 mg/mL의 농도일 때 물 및 에탄올 추출물 모두 세포의 생장에 영향을 미치지 않는 것으로 나타나 세포에 대한 독성이 없다고 판단되었다. 동일한 농도로 3T3-L1 지방세포의 지방축적에 미치는 영향은 물 및 에탄올 추출물 모두 농도 의존적으로 지방축적
후박추출물은 중국 원산인 당후박에서 제조되며, 항산화 및 항염증 효과로 알려져 있다. 후박의 성분으로는 폴레페놀인 honokiol 및 magnolol 등이 알려져 있다. 이 연구에서, 우리는 후박추출물이 triglyceride (TG)의 축척을 감소시킴으로써 지방세포 분화를 억제한다는 표면적인 결과를 얻었다. 또한, 후박 추출물이 hormone sensitive lipase (HSL) 단백질 수준을 증가시키고 adipocyte에 specific한 transcription factors로 peroxisome proliferator activated receptor (PPAR)-γ의 단백질과 mRNA 수준을 억제하였다. 결과적으로, 후박추출물이 항비만제로서 adipogenic transcription factor와 그들의 특이적인 유전자의 발현을 억제함으로써 지방세포 분화를 억제한다고 사료된다.