Silymarin Prevents High-Fat Diet-Induced Muscle Atrophy by Regulating Protein Degradation and Synthesis in Mice.

Silymarin is found in Silybum marianum. We investigated the effect of silymarin on muscle atrophy in obese mice. The experimental mice were divided into three groups: CON, normal diet; HFD, 60% high-fat diet (HF); and SILY: 50 mg silymarin +60% HF. It was confirmed that increases in body weight and fat mass in the SILY group were significantly inhibited. Moreover, the muscle mass in SILY mice was significantly higher than that in the HFD group. The grip strength in HFD group was significantly reduced, whereas in the SILY group it was higher than that in HFD group. In HFD mice, the mRNA levels of protein degradation factors (muscle ring-finger protein 1 [MuRF-1] and Atrogin-1) were increased and protein synthesis factors (phosphoinositide 3-kinase [PI3K] and Akt) were decreased. However, silymarin was found to elevate the degradation factors as compared with HFD group, whereas it reduced the synthesis factors. The results suggest that silymarin could prevent not only obesity but also muscle atrophy.

Fermented Curcuma longa L. Prevents Alcoholic Fatty Liver Disease in Mice by Regulating CYP2E1, SREBP-1c, and PPAR-α.

We examined the efficacy of fermented Curcuma longa L. (FT) on the development of alcoholic fatty liver in mice and investigated the underlying mechanism. The protective potential of FT against ethanol-induced fatty liver was determined using C57BL/6 male mice allocated into four groups (8 mice/group). Control groups received either distilled water or 5 g/kg body weight (b.w.) per day ethanol for 8 days. Treatment groups were administered either 300 mg/kg b.w. per day of milk thistle or FT before receiving ethanol. FT contained a higher amount of caffeic acid and tetrahydrocurcumin than C. longa. FT pretreatment significantly suppressed the elevated hepatic lipid droplets associated with ethanol ingestion. In comparison with ethanol-treated control, FT pretreated mice showed inhibited cytochrome P4502E1 (CYP2E1), sterol regulatory element-binding protein-1 (SREBP-1c), and acetyl-CoA carboxylase production but elevated AMP-activated protein kinase, peroxisome proliferator-activated receptor-alpha (PPAR-α), and carnitine palmitoyltransferase 1 (CPT-1) levels. Taken together, FT is a promising hepatoprotectant for preventing of alcoholic fatty liver through modulating fatty acid synthesis and oxidation.

Curcuma longa L. Water Extract Enhances Endurance Exercise Capacity by Promoting Intramuscular Mitochondrial Biogenesis in Mice.

We investigated the effect of Curcuma longa L. extract on endurance exercise capacity (EEC). EEC is the ability to exercise continuously and recover quickly, even when tired. C. longa contains antioxidants that contribute beneficial effects on the body. We separated groups of nonexercise (CON), exercise control (Ex-CON), branched-chain amino acid (BCAA) intake, and C. longa water extract (CLW) intake (Ex-CLW). EEC increased on the 28th day of BCAA and CLW intake. Both treatment groups exhibited decreased lactate levels with increased levels of nonesterified fatty acids and muscular glycogen compared with the Ex-CON group. Also, the Ex-CLW group possessed higher intramuscular antioxidant enzyme activities (catalase, superoxide dismutase, and glutathione peroxidase) than the Ex-CON group. The expression of PGC-1α, NRF, and Tfam, which are factors related to mitochondrial biogenesis, increased in the Ex-CLW group. Results suggest that CLW intake elevated EEC by increasing intramuscular mitochondrial biogenesis through suppressing the accumulation of fatigue substances and increasing fat consumption, and antioxidant enzyme activity.

Water Extract of Rubus coreanus Prevents Inflammatory Skin Diseases In Vitro Models.

Atopic dermatitis (AD) is a chronic inflammatory skin disease caused by immune hypersensitivity reaction. The cause of AD is unclear, but its symptoms have a negative effect on quality of life; various treatment methods to alleviate these symptoms are underway. In the present study, we aimed to evaluate in vitro antioxidant and anti-inflammatory effects of Rubus coreanus water extract (RCW) on AD. Total phenolic compounds and flavonoid content of RCW were 4242.40 ± 54.84 mg GAE/g RCE and 1010.99 ± 14.75 mg CE/g RCW, respectively. RCW reduced intracellular reactive oxygen species level and increased the action of antioxidant enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase in tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ)-stimulated HaCaT cells. Moreover, mRNA expression of the pro-inflammatory cytokines, including TNF-α, interleukin-1ß, and interleukin-6, was downregulated by RCW in the TNF-α/IFN-γ-stimulated cells. The levels of inflammatory chemokines (thymus- and activation-regulated chemokine; eotaxin; macrophage-derived chemokine; regulated on activation, normal T-cell expressed and secreted; and granulocyte-macrophage colony-stimulating factor) and intercellular adhesion molecule-1 were decreased in the TNF-α/IFN-γ-stimulated HaCaT cells after RCW treatment. Additionally, the mRNA expression levels of filaggrin and involucrin, proteins that form the skin, were increased by RCW. Furthermore, RCW inhibited the nuclear factor kappa-light-chain-enhancer of the activated B cells pathway in the TNF-α/IFN-γ-stimulated HaCaT cells. Collectively, the present investigation indicates that RCW is a potent substance that inhibits AD.

Curcuma longa L. Water Extract Improves Dexamethasone-Induced Sarcopenia by Modulating the Muscle-Related Gene and Oxidative Stress in Mice.

Dexamethasone (DEX) promotes proteolysis, which causes muscle atrophy. Muscle atrophy is connected to sarcopenia. We evaluated the effect of Curcuma longa L. water extract (CLW) on DEX-induced muscle atrophy. ICR mice were divided into three groups (eight mice per group) to investigate the capability of CLW in inhibiting muscle atrophy. The control group (Ex-CON) was administered distilled water (DW) by gavage and subjected to exercise; the muscle atrophy group (Ex-DEX) was administered DW by gavage, an injection of DEX (1 mg/kg body weight/day) intraperitoneally (IP), and subjected to exercise; and the treatment group (Ex-CLW) was administered CLW (1 g/kg body weight/day) by gavage, DEX IP injection, and subjected to exercise. Following the injection of DEX, the expression levels of myostatin, MuRF-1, and Atrogin-1 were increased. However, these expression levels were decreased in the Ex-CLW group, thereby leading to the conclusion that CLW inhibits muscle atrophy. ROS (that was overproduced by DEX) decreased antioxidant enzyme activity and increased malondialdehyde (MDA) levels, which led to muscle atrophy. When CLW was ingested, the antioxidant enzyme activities increased while the MDA levels decreased. These findings suggest that CLW could serve as a natural product for the prevention of muscle atrophy by modulating muscle atrophy-related genes and increasing antioxidant potential.

Ethanolic Extract of Vaccinium corymbosum Alleviates Muscle Fatigue in Mice.

The aim of this study was to evaluate the effects of ethanol extracts of Vaccinium corymbosum (VCE) on exercise-induced fatigue in mice. Mice were randomly divided into three groups; nonexercise control group (CON), exercise control group (Ex-CON), and exercise and VCE supplementation group (Ex-VCE). Compared with Ex-CON, Ex-VCE showed increased endurance exercise capacity on day 21. In Ex-VCE mice, the accumulation of lactate was inhibited and the consumption of fatty acids was enhanced, indicating the delay of muscle fatigue. In addition, VCE supplementation elevated mRNA expression levels of mitochondrial biogenesis-associated genes such as peroxisome proliferator-activated receptor-1γ coactivator 1α (PGC-1α), nuclear respiratory factor (NRF), and mitochondrial transcription factor A (Tfam) and fatty acid ß-oxidation-associated genes such as carnitine palmitoyltransferase-1 (CPT-1), ß-hydroxyacyl coenzyme A dehydrogenase (ß-HAD), and peroxisome proliferator-activated receptor-δ (PPAR-δ). These results suggest that VCE can potentially prevent muscle fatigue by enhancing mitochondrial biogenesis and fatty acid ß-oxidation.

Immunomodulatory Effect of a Salvia plebeia R. Aqueous Extract in Forced Swimming Exercise-induced Mice.

This study investigated the immunomodulatory effect of Salvia plebeia R. aqueous extract (FIE-SP, SPW) in forced swimming exercise-induced mice and the immunostimulatory effects on Raw264.7 cells. Mice were randomly assigned to four groups: the control group (CON), the forced swimming test group (FST), and two FIE-SP groups (low and high dose of FIE-SP). Compared with the control group, the FIE-SP groups showed significantly increased ratios of T lymphocyte surface markers CD4+/CD8+ and major histocompatibility complex (MHC)I/MHCII, as well as increased concentrations of immunoglobulin (Ig)A and IgG. FIE-SP groups significantly increased Th1 cytokines and decreased Th2 cytokines compared with negative control exercise-induced mice. Conversely, the immunostimulatory effects of FIE-SP significantly increased phagocytic activities, nitric oxide (NO) production, and pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin (IL)-1ß in Raw264.7 cells. Furthermore, FIE-SP increased natural killer (NK) cell activities and cytokines (IL-12) in splenocytes compared with the CON group. These results indicated that FIE-SP supplementation could prevent imbalanced immune states and produce immunostimulatory effects to support innate immunity.

Water Extract of Curcuma longa L. Ameliorates Non-Alcoholic Fatty Liver Disease.

Our aim was to investigate whether hot water extract (CLW) of Curcuma longa L. could prevent non-alcoholic fatty liver disease (NAFLD). HepG2 cells were treated with free fatty acid (FFA) mixture (oleic acid: palmitic acid, 2:1) for 24 h to stimulate in vitro fatty liver. In addition, C57BL/6 mice were fed 60 kcal% high-fat (HF) diet for eight weeks to induce fatty liver in vivo. Intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) productions were increased by FFA and HF-diet, but supplementation with CLW significantly decreased these levels. CLW treatment ameliorated antioxidant activities that were suppressed by exposure to the FFA and HF-diet. Cluster of differentiation 36 (CD36) and fatty acid transport proteins (FATP2 and FATP5) were increased in HF-diet groups, while CLW suppressed their expression levels. Moreover, sterol regulatory element-binding protein-1c (SREBP-1c), acetyl-coenzyme A carboxylase (ACC), and fatty acid synthase (FAS) expression levels were down-regulated in the CLW groups compared to HF-diet groups. On the other hand, 5' adenosine monophosphate-activated protein kinase (AMPK), Peroxisome proliferator-activated receptor alpha (PPAR-α), and carnitine palmitoyltransferase 1 (CPT-1) expressions were up-regulated in the CLW groups. HF-diet fed mice showed high hepatic triglycerides (TG) content compared to the normal diet mice. However, the administration of CLW restored the hepatic TG level, indicating an inhibitory effect against lipid accumulation by CLW. These results suggest that CLW could be a potentially useful agent for the prevention of NAFLD through modulating fatty acid uptake.

Smad7 and Smad6 bind to discrete regions of Pellino-1 via their MH2 domains to mediate TGF-beta1-induced negative regulation of IL-1R/TLR signaling.

Transforming growth factor-beta1 (TGF-beta1) performs diverse cellular functions, including anti-inflammatory activity. The inhibitory Smad (I-Smad) Smad6 was previously shown to play an important role in TGF-beta1-induced negative regulation of Interleukin-1/Toll-like receptor (IL-1R/TLR) signaling through binding to Pellino-1, an adaptor protein of interleukin-1 receptor associated kinase 1(IRAK1). However, it is unknown whether Smad7, the other inhibitory Smad, also has a role in regulating IL-1R/TLR signaling. Here, we demonstrate that endogeneous Smad7 and Smad6 simultaneously bind to discrete regions of Pellino-1 upon TGF-beta1 treatment, via distinct regions of the Smad MH2 domains. In addition, the Smad7-Pellino-1 interaction abrogated NF-kappaB activity by blocking formation of the IRAK1-mediated IL-1R/TLR signaling complex, subsequently causing reduced expression of pro-inflammatory genes. Double knock-down of endogenous Smad6 and Smad7 genes by RNA interference further reduced the anti-inflammatory activity of TGF-beta1 than when compared with single knock-down of Smad7. These results provide evidence that the I-Smads, Smad6 and Smad7, act as critical mediators for effective TGF-beta1-mediated suppression of IL-1R/TLR signaling, by simultaneous binding to discrete regions of Pellino-1.

14-3-3 sigma and 14-3-3 zeta plays an opposite role in cell growth inhibition mediated by transforming growth factor-beta 1.

The expression of 14-3-3 proteins is dysregulated in various types of cancer. This study was undertaken to investigate the effects of 14-3-3 zeta and 14-3-3 sigma on cell growth inhibition mediated by transforming growth factor-beta 1 (TGF-beta1). Mouse mammary epithelial cells (Eph4) that are transformed with oncogenic c-H-Ras (EpRas) and no longer sensitive to TGF-beta1-mediated growth inhibition displayed increased expression of 14-3-3 zeta and decreased expression of 14-3-3 sigma compared with parental Eph4 cells. Using small interfering RNA-mediated knockdown and overexpression of 14-3-3 sigma or 14-3-3 zeta, we showed that 14-3-3 sigma is required for TGF-beta1-mediated growth inhibition whereas 14-3-3 zeta negatively modulates this growth inhibitory response. Notably, overexpression of 14-3-3 zeta increased the level of Smad3 protein that is phosphorylated at linker regions and cannot mediate the TGF-beta1 growth inhibitory response. Consistent with this finding, mutation of the 14-3-3 zeta phosphorylation sites in Smad3 markedly reduced the 14-3-3 zeta-mediated inhibition of TGF-beta1-induced p15 promoter-reporter activity and cell cycle arrest, suggesting that these residues are critical targets of 14-3-3 zeta in the suppression of TGF-beta1-mediated growth. Taken together, our findings indicate that dysregulation of 14-3-3 sigma or 14-3-3 zeta contributes to TGF-beta1 resistance in cancer cells.

Geldanamycin inhibits TGF-beta signaling through induction of Hsp70.

Dysregulation of transforming growth factor-beta (TGF-beta) signaling has been implicated in the pathogenesis of a variety of diseases including cancer; therefore, pharmacological inhibitors that target the TGF-beta signaling pathway might be promising drugs for disease therapy. In this study, we investigated the mechanism of inhibition of TGF-beta signaling by the Hsp90 inhibitor geldanamycin (GA). Treatment with GA suppressed TGF-beta signaling, as evidenced by inhibition of TGF-beta-induced phosphorylation and transcriptional activity of Smad3 and decreased induction of target genes. Western blot analysis revealed that GA induced degradation of TGF-beta type I and type II receptors through a proteasome-dependent pathway. Notably, induction of Hsp70 by GA correlated with inhibition of TGF-beta signaling. Suppression of Hsp70 expression by Hsp70 siRNA or KNK437, an inhibitor of Hsp70 synthesis, blocked the inhibition of TGF-beta signaling by GA. Furthermore, Hsp70 interacted directly with TGF-beta receptors following GA treatment. Our results suggest that GA-mediated induction of Hsp70 and its subsequent interaction with TGF-beta receptors plays a crucial role in inhibition of TGF-beta signaling.