Role of dietary curcumin against waterborne lead toxicity in common carp Cyprinus carpio.

Curcumin exhibited numerous key activities including antioxidant, anti-inflammatory, and immunostimulatory effects in fish. This study evaluated the protective effects of curcumin (CUR) against lead (Pb)-induced toxicities in fish. Healthy Cyprinus carpio L. individuals were segregated into control, Pb only, Pb+CUR, and CUR only groups. Pb groups were exposed to 1 mg L -1 of Pb, and CUR groups were fed a basal diet supplemented with 15 g kg-1 of CUR. After eight weeks, growth performance, Pb accumulation in tissues, various haemato-biochemical parameters, immune responses, and cytokine gene expression were measured. Dietary CUR effectively decreased Pb accumulation in tissues and increased the survival of Pb-exposed fish. Co-treatment with Pb and CUR reversed alterations in haemato-biochemical parameters, ameliorated Pb-induced oxidative stress, enhanced immune responses, and restored intestinal enzymatic activities. Dietary CUR reversed changes in intestinal microbiota in Pb-exposed fish. Pb-induced upregulation of NF-κBp65 and HSP70 was inhibited by dietary CUR. CUR supplementation upregulated the mRNA levels of SOD, Nrf2, IL-10, and CYP450 1A and attenuated Pb-induced degradation of I κB-α mRNA levels. Overall, CUR antagonizes Pb-induced negative impacts in fish. Thus, dietary CUR had several beneficial effects on immune responses, decreased Pb accumulation in tissues, and reversed Pb-induced oxidative stress in fish. Therefore, CUR plays a protective role in Pb-induced immune toxicity in fish, and, as such, may be suitable as an aqua feed additive for use in carp aquaculture.

Wogonin induces apoptosis by suppressing E6 and E7 expressions and activating intrinsic signaling pathways in HPV-16 cervical cancer cells.

Wogonin is a flavonoid compound extracted from Scutellaria baicalensis and is well known as a benzodiazepine receptor ligand with anxiolytic effects. Many recent studies have demonstrated that wogonin modulates angiogenesis, proliferation, invasion, and tumor progress in various cancer tissues. We further explored the mechanism of action of wogonin on cervical cancer cells that contain or lack human papillomavirus (HPV) DNA. Wogonin was cytotoxic to HPV 16 (+) cervical cancer cells, SiHa and CaSki, but not to HPV-negative cells. We demonstrated that wogonin induced apoptosis by suppressing the expressions of the E6 and E7 viral oncogenes in HPV-infected cervical cancer CaSki and SiHa cells. The modulation of p53 and protein retinoblastoma (pRb) were also triggered by the suppression of E6 and E7 expressions. However, p53 was not altered in HPV-negative cervical cancer C33A cells. Moreover, wogonin modulated the mitochondrial membrane potential and the expression of pro- and anti-apoptotic factors such as Bax and Bcl-2. Wogonin also provoked the cleavage of caspase-3, caspase-9, and poly ADP ribose polymerase. After transfection of siRNAs to target E6 and E7, additional restoration of p53 and pRb was not induced, but processing of caspases and PARP was increased compared with wogonin treatment alone. Together, our findings demonstrated that wogonin effectively promotes apoptosis by downregulating E6 and E7 expressions and promoting intrinsic apoptosis in human cervical cancer cells.

Antiobesity effects of a sulfur compound thiacremonone mediated via down-regulation of serum triglyceride and glucose levels and lipid accumulation in the liver of db/db mice.

Garlic is widely used as a spice. Garlic extracts exert anticancer and antiinflammatory effects, but its antiobesity efficacy studies have produced conflicting results. The antiobesity effects of thiacremonone, a sulfur compound isolated from garlic, was evaluated in obese db/db mice. Thiacremonone was orally administrated to mice for 3 weeks. The thiacremonone-treated db/db mice showed a loss of body weight and decrease in blood triglyceride and glucose levels compared with the control mice. Histological analysis further revealed that thiacremonone significantly decreased lipid accumulation in the fatty livers of treated db/db mice. It was observed that GLUT-4 expression and glucose uptake were up-regulated by thiacremonone in 3T3-L1 adipocytes. Thiacremonone treatment also suppressed expression levels of acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS), which are involved in lipid metabolism, in the liver of db/db mice. In addition, thiacremonone enhanced peroxisome proliferator-activated receptor γ (PPARγ) expression in the fatty liver. Taken together, these results suggest that thiacremonone may play a vital role in improving the management of obesity and related metabolic syndromes via inhibition of lipid accumulation.

The biflavonoid amentoflavone induces apoptosis via suppressing E7 expression, cell cycle arrest at sub-G1 phase, and mitochondria-emanated intrinsic pathways in human cervical cancer cells.

Amentoflavone, a biflavonoid from Selaginella tamariscina, is known to possess several bioactivities such as antitumor, anti-inflammatory, and antifungal effects. However, the mechanism of the anticancer effects of amentoflavone on human cervical cancer cells has not been studied in detail. In this study, we demonstrated that amentoflavone induces apoptosis in SiHa and CaSki cervical cancer cells by suppressing human papillomavirus protein E7 expression. The cyclins and tumor suppressors were modulated by amentoflavone in SiHa and CaSki human cervical cancer cells: cyclin and hyperphosphorylated retinoblastoma (p-pRb) were down-regulated, whereas cyclin-dependent kinase inhibitors and p53 were enhanced. Amentoflavone up-regulated peroxisome proliferator-activated receptor γ (PPARγ) and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression levels while inhibiting E7-mediated cyclooxygenase-2 (COX-2)/interleukin-32 (IL-32) expressions were downregulated, and Akt phosphorlylation was decreased in an amentoflavone-induced apoptotic process, suggesting that amentoflavone may be a PPARγ activator. Additionally, the expression of the anti-apoptotic factor Bcl-2 was decreased, whereas that of the well-known apoptotic factor Bax was increased, thereby releasing cytochrome c into cytosol in amentoflavone-treated cervical cancer cells. Furthermore, amentoflavone treatment led to the activation of caspase-3 and -9 and proteolytic cleavage of poly(ADP-ribose) polymerase. The expression level of the extrinsic death receptor Fas (CD95) was not altered by amentoflavone treatment. When these findings are taken together, the biflavonoid amentoflavone activates PPARγ/PTEN expressions and induces apoptosis via suppressing E7 expression, cell cycle arrest at sub-G1 phase, and mitochondria-emanated intrinsic pathways in SiHa and CaSki human cervical cancer cells. These findings suggest that amentoflavone has potential for development as a therapeutic agent for human cervical cancer.

The liquid Panax ginseng inhibits epidermal growth factor-induced metalloproteinase 9 and cyclooxygenase 2 expressions via inhibition of inhibitor factor kappa-B-alpha and extracellular signal-regulated kinase in NCI-H292 human airway epithelial cells.

BACKGROUND: Ginseng (Panax ginseng C.A. Meyer) has been used in Asian countries for the treatment of various diseases. However, the mechanisms of liquid Panax ginseng (LG) on allergic inflammatory response in epidermal growth factor (EGF)-stimulated human airway epithelial cells remain largely unclear. METHODS: MUC5AC, cyclooxygenase (COX) 2, and matrix metalloproteinase (MMP) 9 expressions were measured using reverse transcription-polymerase chain reaction, Western blotting, and gelatin zymogram analyses in NCI-H292 cells. Extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) protein levels were analyzed by Western blotting. RESULTS: To gain insight into the antiallergy effects of LG, we examined its influence on epidermal growth factor (EGF)-induced MMP-9 and COX-2 productions in NCI-H292 cells. LG was treated for 1 hour and then followed by EGF treatment for 24 hours into NCI-H292 cells. The decrease of COX-2 production was correlated with the reduced levels of proteins and mRNAs of inducible MMP-9 and MUC5AC. LG blocked upstream signaling of NF-kappa-B activation via inhibition of phosphorylations of inhibitor factor-kappa- B-alpha (I-kappa-B-alpha) and ERK. These results suggest that LG protects NCI-H292 cells from EGF-induced damage by down-regulation of COX-2, MMP-9, and MUC5AC gene expressions by blocking NF-kappa-B and ERK. CONCLUSION: LG modulates allergic inflammatory response in EGF-stimulated NCI-H292 human airway epithelial cells via inhibition of I-kappa-B-alpha and ERK.

Novel PPARγ partial agonists with weak activity and no cytotoxicity; identified by a simple PPARγ ligand screening system.

Peroxisome proliferator-activated receptors (PPARs) are the transcriptional factor that regulate glucose and lipid homeostasis and widely well-known as molecular targets for improvement of metabolic disorder. Because major transcriptional activity of PPARs depends on their proper ligands, the studies for PPAR ligands have been continuously developed. We previously reported the simple enzyme-linked immunosorbent assay (ELISA) systems to screen PPAR ligands and a chemical library including flavonoid derivatives have applied to these systems. In this study, we introduce two compounds (KU16476 and KU28843) identified as PPARγ partial agonists by a screening ELISA for PPARγ ligand. KU16476 and KU28843 significantly increased binding between PPARγ and SRC-1 in a simple ELISA system. Co-activator recruiting-induced abilities of two compounds were less than that of indomethacin, a well-known PPARγ agonist. To determine whether these compounds would be PPARγ partial agonists, each candidate with indomethacin were applied to a simple ELISA based on binding between PPARγ and SRC-1. Cotreatment with indomethacin significantly increased binding between PPARγ and SRC-1 than treatment of indomethacin or candidate alone. Two compounds had no considerable cytotoxicities, induced partial adipogenesis, and accumulated lipid droplets in 3T3-L1 fibroblast. Also, these two compounds enhanced expression of PPARγ-mediated genes such as aP2 and UCP-2. By docking study, we confirmed that two compounds bound well to the active site of PPARγ with hydrophobic interactions. We suggest that two compounds identified by a simple ELISA system can be PPARγ partial agonists. These PPARγ partial agonists and these studies to find out novel PPARγ agonists may contribute to drug development against metabolic disorders.

Effects of a tetramethoxyhydroxyflavone p7f on the expression of inflammatory mediators in LPS-treated human synovial fibroblast and macrophage cells.

The inhibitory effects of 5,6,3',5'-tetramethoxy 7,4'-hydroxyflavone (labeled as p7F) were elucidated on the productions of proinflammatory cytokines as well as inflammatory mediators in human synovial fibroblasts and macrophage cells. p7F inhibited IL-1beta or TNF-alpha induced expressions of inflammatory mediators (ICAM-1, COX-2, and iNOS). p7F also inhibited LPS-induced productions of nitric oxide and prostaglandin E2 in RAW 264.7 cells. In order to investigate whether p7F would inhibit IL-1 signaling, p7F was added to the D10S Th2 cell line (which is responsive to only IL-1beta and thus proliferates), revealing that p7F inhibited IL-1beta-induced proliferation of D10S Th2 cells in a doseresponse manner. A flow cytometric analysis revealed that p7F reduced the intracellular level of free radical oxygen species in RAW 264.7 cells treated with hydrogen peroxide. p7F inhibited IkappaB degradation and NF-kappaB activation in macrophage cells treated with LPS, supporting that p7F could inhibit signaling mediated via toll-like receptor. Taken together, p7F has inhibitory effects on LPS-induced productions of inflammatory mediators on human synovial fibroblasts and macrophage cells and thus has the potential to be an antiinflammatory agent for inhibiting inflammatory responses.

A simple method to screen ligands of peroxisome proliferator-activated receptor delta.

Peroxisome proliferator-activated receptors (PPARs) are transcription factors that belong to the nuclear receptor superfamily directly modulating gene expression by binding to specific ligands. Recently, it has been reported that PPARdelta ligands play an essential role in improvement of metabolic disorders and skin disorders. We introduce an enzyme-linked immunosorbent assay (ELISA) to screen new PPARdelta ligands. This method is based on the activation mechanism of PPARdelta where the ligand binding to PPARdelta induces the interaction of the receptor with transcriptional co-activators. We optimized a simple ELISA method for screening PPARdelta ligands. Among co-activators such as SRC-1, TIF-2, and p300, PPARdelta had more strong binding with SRC-1 in an ELISA system. GW501516 and linoleic acid, the well-known ligands of PPARdelta, increased the binding between PPARdelta and co-activators in a ligand dose-dependent manner. The recruitment of co-activator SRC-1 was also more effective than those of TIF-2 and p300. We optimized and developed a novel and useful ELISA system for the mass screening of PPARdelta ligands. This screening system may be useful in the development of drugs for metabolic disorders and skin disorders.