Protective Effect of Caffeic Acid Derivatives on tert-Butyl Hydroperoxide-Induced Oxidative Hepato-Toxicity and Mitochondrial Dysfunction in HepG2 Cells.

Oxidative stress results in structural and functional abnormalities in the liver and is thought to be a crucial factor in liver diseases. The aim of this study was to investigate the cytoprotective and antioxidant effects of caffeic acid (CA) derivatives on tert-butyl hydroperoxide (t-BHP)-induced oxidative stress in HepG2 cells. Nine CA derivatives were synthesized, including N-phenylethyl caffeamide (PECA), N-(3-florophen)methyl caffeamide (FMCA), N-(4-methoxy-phen)methyl caffeamide (MPMCA), N-heptyl caffeamide (HCA), N-octyl caffeamide (OCA), octyl caffeate (CAOE), phenpropyl caffeate (CAPPE), phenethyl caffeate (CAPE), and phenmethyl caffeate (CAPME). The results showed that CA and its derivatives significantly inhibited t-BHP-induced cell death of HepG2 cells. The rank order of potency of the CA derivatives for cytoprotection was CAOE > HCA > OCA > FMCA > CAPPE > CAPME > CAPE > PECA > MPMCA > CA. Their cytoprotective activity was associated with lipophilicity. The antioxidant effect of these compounds was supported by the reduction in the levels of thiobarbituric acid reactive substrates, a biomarker of lipid peroxidation, in HepG2 cells. Pre-treatment of CA derivatives significantly prevented the depletion of glutathione, the most important water-soluble antioxidant in hepatocytes. Pre-treatment of CA derivatives before t-BHP exposure maintained mitochondrial oxygen consumption rate and ATP content in the injured HepG2 cells. CA derivatives except OCA and HCA significantly suppressed t-BHP-induced hypoxia-inducible factor-1α (HIF-1α) protein level. In addition, all of these CA derivatives markedly increased the nuclear factor erythroid 2-related factor 2 (Nrf2) accumulation in the nucleus, indicating that their cytoprotection may be mediated by the activation of Nrf2. Our results suggest that CA derivatives might be a hepatoprotective agent against oxidative stress.

Metabolite identification for mass spectrometry-based metabolomics using multiple types of correlated ion information.

Metabolite identification remains a bottleneck in mass spectrometry (MS)-based metabolomics. Currently, this process relies heavily on tandem mass spectrometry (MS/MS) spectra generated separately for peaks of interest identified from previous MS runs. Such a delayed and labor-intensive procedure creates a barrier to automation. Further, information embedded in MS data has not been used to its full extent for metabolite identification. Multimers, adducts, multiply charged ions, and fragments of given metabolites occupy a substantial proportion (40-80%) of the peaks of a quantitation result. However, extensive information on these derivatives, especially fragments, may facilitate metabolite identification. We propose a procedure with automation capability to group and annotate peaks associated with the same metabolite in the quantitation results of opposite modes and to integrate this information for metabolite identification. In addition to the conventional mass and isotope ratio matches, we would match annotated fragments with low-energy MS/MS spectra in public databases. For identification of metabolites without accessible MS/MS spectra, we have developed characteristic fragment and common substructure matches. The accuracy and effectiveness of the procedure were evaluated using one public and two in-house liquid chromatography-mass spectrometry (LC-MS) data sets. The procedure accurately identified 89% of 28 standard metabolites with derivative ions in the data sets. With respect to effectiveness, the procedure confidently identified the correct chemical formula of at least 42% of metabolites with derivative ions via MS/MS spectrum, characteristic fragment, and common substructure matches. The confidence level was determined according to the fulfilled identification criteria of various matches and relative retention time.

Dietary fucoxanthin increases metabolic rate and upregulated mRNA expressions of the PGC-1alpha network, mitochondrial biogenesis and fusion genes in white adipose tissues of mice.

The mechanism for how fucoxanthin (FX) suppressed adipose accumulation is unclear. We aim to investigate the effects of FX on metabolic rate and expressions of genes related to thermogenesis, mitochondria biogenesis and homeostasis. Using a 2 × 2 factorial design, four groups of mice were respectively fed a high sucrose (50% sucrose) or a high-fat diet (23% butter + 7% soybean oil) supplemented with or without 0.2% FX. FX significantly increased oxygen consumption and carbon dioxide production and reduced white adipose tissue (WAT) mass. The mRNA expressions of peroxisome proliferator-activated receptor (PPAR) γ coactivator-1α (PGC-1α), cell death-inducing DFFA-like effecter a (CIDEA), PPARα, PPARγ, estrogen-related receptor α (ERRα), ß3-adrenergic receptor (ß3-AR) and deiodinase 2 (Dio2) were significantly upregulated in inguinal WAT (iWAT) and epididymal WAT (eWAT) by FX. Mitochondrial biogenic genes, nuclear respiratory factor 1 (NRF1) and NRF2, were increased in eWAT by FX. Noticeably, FX upregulated genes of mitochondrial fusion, mitofusin 1 (Mfn1), Mfn2 and optic atrophy 1 (OPA1), but not mitochondrial fission, Fission 1, in both iWAT and eWAT. In conclusion, dietary FX enhanced the metabolic rate and lowered adipose mass irrespective of the diet. These were associated with upregulated genes of the PGC-1α network and mitochondrial fusion in eWAT and iWAT.

Two novel vitamin D receptor modulators with similar structures exhibit different hypercalcemic effects in 5/6 nephrectomized uremic rats.

BACKGROUND/AIMS: Vitamin D receptor modulators (VDRMs) are indicated for secondary hyperparathyroidism in chronic kidney disease (CKD). Clinical observations demonstrate that VDRM therapy provides cardiovascular (CV) benefit in CKD. Current on-market VDRMs have a narrow therapeutic index at 1- to 4-fold [hypercalcemic toxicity vs. parathyroid hormone (PTH)-suppressing efficacy]. Hypercalcemia leads to the need for frequent drug dose titration and serum calcium (Ca) monitoring. A VDRM with a wider therapeutic index and beneficial CV effects will be clinically useful. METHODS: Two structurally similar VDRMs were tested in the 5/6 nephrectomized (NX) rats with elevated PTH, endothelial dysfunction and left ventricular hypertrophy. RESULTS: VS-110 and VS-411 at 0.01-1 µg/kg (i.p. 3 times/week for 2 weeks) suppressed serum PTH effectively. VS-411 raised serum Ca with an 11% increase at 0.01 µg/kg (therapeutic index = ~1-fold), while VS-110 did not raise serum Ca even at 1 µg/kg (therapeutic index >50-fold). VS-110 improved endothelium-dependent aortic relaxation in a dose-dependent manner and significantly reduced left ventricular fibrosis without affecting serum Ca. VS-411 also exhibited effects on the CV parameters, but was less potent at the high doses with severe hypercalcemia. VS-110 and VS-411 specifically activated the reporter gene via a chimeric receptor containing the VDR ligand binding domain with EC(50) <0.1 nM. CONCLUSIONS: Structurally similar VDRMs can exhibit distinctly different hypercalcemic effects in 5/6 NX uremic rats. While differences exist for the Ca and CV effects of VS-110 and VS-411, the clinical implications are unclear. VS-110's results are promising but clinical outcome studies need to be performed.

Wild bitter gourd improves metabolic syndrome: a preliminary dietary supplementation trial.

BACKGROUND: Bitter gourd (Momordica charantia L.) is a common tropical vegetable that has been used in traditional or folk medicine to treat diabetes. Wild bitter gourd (WBG) ameliorated metabolic syndrome (MetS) in animal models. We aimed to preliminarily evaluate the effect of WBG supplementation on MetS in Taiwanese adults. METHODS: A preliminary open-label uncontrolled supplementation trial was conducted in eligible fulfilled the diagnosis of MetS from May 2008 to April 2009. A total of 42 eligible (21 men and 21 women) with a mean age of 45.7 ± 11.4 years (23 to 63 years) were supplemented with 4.8 gram lyophilized WBG powder in capsules daily for three months and were checked for MetS at enrollment and follow-up monthly. After supplementation was ceased, the participants were continually checked for MetS monthly over an additional three-month period. MetS incidence rate were analyzed using repeated-measures generalized linear mixed models according to the intention-to-treat principle. RESULTS: After adjusting for sex and age, the MetS incidence rate (standard error, p value) decreased by 7.1% (3.7%, 0.920), 9.5% (4.3%, 0.451), 19.0% (5.7%, 0.021), 16.7% (5.4%, 0.047), 11.9% (4.7%, 0.229) and 11.9% (4.7%, 0.229) at visit 2, 3, 4, 5, 6, and 7 compared to that at baseline (visit 1), respectively. The decrease in incidence rate was highest at the end of the three-month supplementation period and it was significantly different from that at baseline (p = 0.021). The difference remained significant at end of the 4th month (one month after the cessation of supplementation) (p = 0.047) but the effect diminished at the 5th and 6th months after baseline. The waist circumference also significantly decreased after the supplementation (p < 0.05). The WBG supplementation was generally well-tolerated. CONCLUSION: This is the first report to show that WBG improved MetS in human which provides a firm base for further randomized controlled trials to evaluate the efficacy of WBG supplementation.

Isolation and optimisation of the oleaginous yeast Sporobolomyces roseus for biosynthesis of 13C isotopically labelled 18-carbon unsaturated fatty acids and trans 18:1 and 18:2 derivatives through synthesis.

An oleaginous and psychrotrophic strain (F38-3) of Sporobolomyces roseus Kluyver & van Niel was isolated from a salt marsh environment in Nova Scotia, Canada following a screening program to select for high producers of 18-carbon unsaturated fatty acids. Fatty acid production was characterised as a function of temperature at 20 g glucose L(-1), and optimal yields were obtained at 14°C, achieving 5.7 g dw biomass and 39.2% total fatty acids by dry weight, with 18:1, 18:2 and 18:3 all-cis fatty acids accounting for 49.4%, 14.3% and 6.7% of total fatty acids (TFA), respectively--the highest reported for this species. Production of 18:3 was inversely correlated to growth temperature, rising from 2% of TFA at 30°C to 8.9% at 6°C. Cultivation of isolate F38-3 on universally (13)C (U-(13)C) labelled glucose and subsequent transesterification and isolation of the fatty acid methyl esters (FAMEs) by preparative chromatography yielded pure, highly (13)C-enriched (>90%) 18:1, 18:2 and 18:3 all-cis FAMEs. The U-(13)C 18:1 FAME was catalytically converted to U-(13)C 18:1 trans-9 and purified to >99.5% purity. The U-(13)C 18:2 was converted by alkaline isomerisation into a 50/50 mixture of 18:2 cis-9, trans-11 and 18:2 trans-10, cis-12 isomers and purified to >95.0% purity. Overall, 10%, by weight, of labelled glucose fed to isolate F38-3 was recovered as fatty acid methyl esters and 7.5% as 18-carbon unsaturated fats, and the final isomerisation reactions resulted in yields of 80% or greater. The ultimate goal of the work is to develop methodologies to produce (13)C-labelled metabolic tracers as tools to study the metabolism of trans fats.

Dietary wild bitter gourd displays selective androgen receptor modulator like activity and improves the muscle decline of orchidectomized mice.

Loss of skeletal muscle mass and strength is often associated with disability and poor quality of life. Selective Androgen Receptor Modulators (SARMs) are under development as potential treatment. This study aims at examining the potential of wild bitter gourd (BG) as a SARM and its effects on the muscle decline induced by orchiectomy. In the cell-based androgen receptor (AR) transactivation assay, the BGP extract showed weak agonistic and antagonistic activities, resembling those of some SARMs. Male C57BL/6J mice were sham-operated (Sham group) or castrated (Cast groups) and fed a modified AIN-93G high sucrose diet supplemented without (Cast group) or with 5% lyophilized BG powder (Cast + BGP) or with testosterone propionate (7 mg TP per kg diet, Cast + TP) for 23 weeks. In contrast to the Cast + TP group, the BGP supplementation did not affect the serum testosterone concentration, and prostate and seminal vesicle mass. Both TP and BGP supplementation increased the weight of androgen responsive muscles, bulbocavernosus (BC) and levator ani (LA) (p < 0.05). The grip strength and the performance on a rotarod of the Cast + BGP group were comparable to those of the Cast + TP group (p > 0.05). The number of succinate dehydrogenase (SDH)-positive fibers of the Cast + BGP group was not significantly different from that of the Sham and Cast + TP groups (p > 0.05). The BGP supplementation up-regulated the Pgc1α, Ucp2 or Ucp3 gene expressions in skeletal muscles of castrated mice (p < 0.05). BGP showed some characteristics of the SARM and might improve skeletal muscle function through the up-regulation of mitochondrial biogenic genes and oxidative capacity, and ameliorated the castration-induced decline of skeletal muscle function in mice.

Postprandial Metabolomics Response to Various Cooking Oils in Humans.

Lipids account for a high proportion of dietary calories, which greatly affect human health. As a result of differences in composition of fatty acid of individual cooking oils, certain biological effects of these oils may vary. This study aimed to compare postprandial metabolomic profiles of six commonly consumed cooking oils/fats. Adopting a switch-over experimental design ( n = 15), we carried out a human feeding study with six groups (control without oils, soybean oil, olive oil, palm oil, camellia oil, and tallow) and collected fasting and postprandial serum samples. The metabolomic profile was measured by ultra-high-pressure liquid chromatography-quadrupole time of flight. We observed significant differences between the control group and experimental groups for 33 serum metabolites (false discovery rate; p < 0.05), which take part in lipid digestion, fatty acid metabolism, metabolism of pyrimidines and pyrimidine nucleosides, amino acid metabolism, neurobiology, and antioxidation. Sparse partial least squares discriminant analysis revealed distinct metabolomics patterns between monounsaturated fatty acid (MUFA) and saturated fatty acid oils, between soybean oil, olive oil, and palm oil, and between two MUFA-rich oils (olive and camellia oils). The present metabolomics study suggests shared and distinct metabolisms of various cooking oils/fats.

Vegetable, fruit, and phytonutrient consumption patterns in Taiwan.

Phytonutrients may play important roles in human health and yet only recently a few studies have described phytonutrient consumption patterns, using data obtained from daily consumption methods. We aimed to estimate the phytonutrient content in Taiwanese diets and analyzed main food sources of 10 major phytonutrients. In this study, food items and dietary data gathered with the 24-hour dietary recall from 2908 participants in the 2005-2008 Nutrition and Health Survey in Taiwan were used to create a food phytonutrient database with 933 plant-based foods through integrating database, literature search, and chemical analysis and to appraise phytonutrient consumption status of participants. SUDAAN (Survey Data Analysis) was used for generating weighted phytonutrient intake estimates and for statistical testing. In Taiwanese adults, ∼20% met the recommended number of servings for fruits and 30% met that for vegetables from the Taiwan Food-Guide recommendations. However, only 7.4% consumed the recommended numbers for both fruits and vegetables. Those meeting the recommendations tended to be older and with more females compared with those who did not. Phytonutrient intake levels were higher in meeters than nonmeeters. More than 60% of α-carotene, lycopene, hesperetin, epigallocatechin 3-gallate, and isoflavones came from a single phytonutrient-specific food source. In addition, sweet potato leaf, spinach, and water spinach were among the top three sources of multiple phytonutrients. Cross-comparison between this study and two previous studies with similar methodology showed higher mean levels of lycopene and quercetin in the United States, anthocyanidins in Korea, and lutein and zeaxanthin in Taiwan. The Taiwanese phytonutrient pattern is different from that of the Korean and American. It would be interesting to relate phytonutrient patterns to health profiles in the future.

Changes in liver PPARalpha mRNA expression in response to two levels of high-safflower-oil diets correlate with changes in adiposity and serum leptin in rats and mice.

The ligand-dependent transcription factor peroxisome proliferator-activated receptor alpha (PPARalpha) is known to be activated by common fatty acids and to regulate the expression of genes of various lipid oxidation pathways and transport. High-fat diets provide more fatty acids, which presumably could enhance lipid catabolism through up-regulation of PPARalpha signaling. However, high intake of fat could also lead to obesity. To examine PPARalpha signaling in high-fat feeding and obesity, this study examined the hepatic mRNA expression of PPARalpha and some of its target genes in Wistar rats and C57BL/6J mice fed two levels (20% or 30% wt/wt) of high-safflower-oil (SFO; oleic-acid-rich) diets until animals showed significantly higher body weight (13 weeks for rats and 22 weeks for mice) than those of control groups fed a 5% SFO diet. At the end of these respective feeding periods, only the rats fed 30% SFO and the mice fed 20% SFO among the two groups fed high-fat diets showed significantly higher body weight, white adipose tissue weight, serum leptin and mRNA expression of PPARalpha (P<.05) compared to the respective control groups. Despite elevated acyl-CoA (a PPARalpha target gene) protein and activity in both groups fed high-fat diets, the mRNA expression level of most PPARalpha target genes examined correlated mainly to PPARalpha mRNA levels and not to fat intake or liver lipid levels. The observation that the liver PPARalpha mRNA expression in groups fed high-fat diets was significantly higher only in obese animals with elevated serum leptin implied that obesity and associated hyperleptinemia might have a stronger impact than dietary SFO intake per se on PPARalpha-regulated mRNA expression in the liver.

Isolation and identification of novel estrogenic compounds in yam tuber (Dioscorea alata Cv. Tainung No. 2).

Yam (Dioscorea spp.) is a common food in tropical areas and has been shown to improve the status of sex hormone in postmenopausal women. In this study, the estrogenic activity of yam was examined and active compounds were isolated and identified based on ligand-dependent transcriptional activation through estrogen receptors. Ethyl acetate extracts of various species/varieties of yam were found to activate estrogen receptors alpha and beta to various extents. The extract of Dioscorea alata cv. Tainung No. 2 tuber was fractionated by repeated silica gel column chromatography. The active compounds were isolated and purified by preparative HPLC. Based on NMR and mass spectrometry, two new compounds, hydro-Q(9) chromene (1) and gamma-tocopherol-9 (2), together with three known compounds, RRR-alpha-tocopherol (3), coenzyme Q(9) (4), and 1-feruloylglycerol (5), were identified and shown to activate human ERalpha and beta. These results provide basic evidence for the beneficial effect of yam for menopausal women.

Low and high levels of alpha-tocopherol exert opposite effects on IL-2 possibly through the modulation of PPAR-gamma, IkappaBalpha, and apoptotic pathway in activated splenocytes.

OBJECTIVE: We previously demonstrated that a high dose of alpha-tocopheryl succinate inhibits interleukin-2 (IL-2) mRNA and production in autoimmune-prone MRL/lpr mice. In the present study, we investigated the regulation of alpha-tocopherol (alphaTOC) on IL-2 gene expression by examining the mRNA of IL-2, inhibitor kappaBalpha (IkappaBalpha), and peroxisome proliferator-activated receptor-gamma (PPARgamma). METHODS: Messenger RNA expression in active splenocytes of BALB/c mice was investigated with reverse transcriptase polymerase chain reaction. RESULTS: Levels of IL-2 mRNA in phorbol 12-myristate 13-acetate/ionomycin activated splenocytes and cytokine in T-helper-1 cells were increased by 50 microM of alphaTOC but decreased by 1 mM of alphaTOC. In addition, the IkappaBalpha gene expression significantly increased by the high dose (>or=500 microM) of alphaTOC, suggesting an inhibition on nuclear factor-kappaB pathway for activation of IL-2 expression. PPARgamma mRNA level in activated splenocytes was upregulated by 1 mM of alphaTOC. PPARgamma mRNA level in unstimulated splenocytes was upregulated by alphaTOC in a dose-dependent manner, suggesting that alphaTOC might enhance the PPARgamma signaling pathway. High-dose alphaTOC induced apoptosis of splenocytes and inhibited phytohemagglutinin-stimulated T-cell proliferation. Conversely, the proliferative response of splenocytes was enhanced by 5 microM of alphaTOC. Low-dose (50 microM) alphaTOC increased IL-2 expression, which may have been due to the absence of downregulation of PPARgamma and IkappaBalpha on the IL-2 gene. CONCLUSION: The results indicated that low and high doses of alphaTOC exert opposite effects on IL-2, possibly through modulation of PPARgamma, IkappaBalpha, and apoptosis pathways. The present findings support our previous observation of opposite effects of low- and high-dose vitamin E on survival of MRL/lpr mice.

Activity-based and fraction-guided analysis of Phyllanthus urinaria identifies loliolide as a potent inhibitor of hepatitis C virus entry.

Without a vaccine, hepatitis C virus (HCV) remains a global medical and socio-economic burden, predisposing about 170 million carriers worldwide to end-stage liver diseases including cirrhosis and hepatocellular carcinoma. Although the recently developed direct-acting antivirals (DAAs) have revolutionized hepatitis C treatment, most of them are unsuitable for monotherapy due to risks of resistance, thus necessitating combination with interferon (IFN)-alpha, ribavirin, or additional DAAs. More importantly, the high cost associated with the DAAs restricts their accessibility to most parts of the world. Developing novel cost-effective anti-HCV therapeutics may help expand the scope of antivirals and treatment strategies against hepatitis C. Herein, we applied an activity-based and fraction-guided analysis of extracts from the medicinal plant Phyllanthus urinaria (P. urinaria), which yielded fraction 13 (F13) as possessing the most potent inhibitory activity against early viral entry of cell-culture HCV infection. Chemical analysis (silica gel chromatography followed by ESI LC-MS plus (1)H and (13)C NMR) of F13 identified loliolide (LOD), a monoterpenoid lactone, as a novel inhibitor of HCV entry. Specifically, LOD could efficiently inactivate HCV free virus particles, abrogate viral attachment, and impede viral entry/fusion, with minimal effect on viral replication/translation, particle production, and induction of type I IFN host antiviral immune response. ELISA-based binding analysis confirmed the monoterpenoid's ability in efficiently blocking HCV particle attachment to the host cell surface. Furthermore, LOD could inhibit infection by several genotypic strains of HCV. This is the first report characterizing P. urinaria and its bioactive compound LOD as potent HCV entry inhibitors, which merit further evaluation for development as candidate antiviral agents against hepatitis C.

Stimulated resistin expression in white adipose of rats with bile duct ligation-induced liver cirrhosis: relationship to cirrhotic hyperinsulinemia and increased tumor necrosis factor-alpha.

Resistin, an adipose-derived polypeptide hormone, is proposed as a candidate of insulin resistance, although its roles in inhibiting adipogenesis and in inflammation have also been suggested. Liver cirrhosis is characterized by elevated circulating proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha), hyperinsulinemia and insulin resistance. The study aimed to examine resistin expression and its association with insulin and TNF-alpha in a cirrhotic rat model using bile duct ligation (BDL). The BDL-induced cirrhotic rats showed significantly lower fat mass, insulin sensitivity and elevated plasma insulin and TNF-alpha compared to sham animals. In addition, epididymal TNF-alpha and resistin mRNA and protein levels were higher in cirrhotic rats. In normal control rats, in vivo insulin infusion and ex vivo administration of TNF-alpha to cultured fat pads increased resistin gene expression significantly. These results implied that hyperinsulinemia and increased TNF-alpha levels might upregulate adipose resistin gene in BDL-induced liver cirrhosis. Further study is necessary to document the role of resistin in metabolic abnormalities of liver cirrhosis.

Peroxisome proliferation in liver of rats fed oxidized frying oil.

Oxidized frying oil (OFO) activates peroxisome proliferator-activated receptor a (PPAR alpha) in vitro and in vivo. As most PPARalpha activators are also peroxisome proliferators (PP), this study was aimed at exploring whether OFO induces peroxisome proliferation in the liver of rats. Four groups of male weanling Sprague-Dawley rats were fed the following diets for 6 wk: a basal diet containing 5 g/100 g fresh soybean oil (LSB), high-fat diets containing 20 g/100 g of fresh soybean oil (HSB as a control). OFO (HO) or fish oil (HF, as a positive control). Hepatomegaly and peroxisome proliferation in the liver of the HO group of rats were higher than those of the HF group. In addition, the acyl-CoA oxidase (ACO) activity, as well as cytochrome P450 4A (CYP4A) protein content in the livers of the HO group were 6 fold those of the HSB group, but were 2.5 fold in those of the HF group. These results indicated that dietary OFO induced typical responses to PPARalpha signaling. Moreover. as a dietary source, the OFO prepared under our frying conditions appears to be a more potent peroxisome proliferator than fish oil.

Fucoxanthin Enhances Chain Elongation and Desaturation of Alpha-Linolenic Acid in HepG2 Cells.

Dietary fucoxanthin (FX), a carotenoid compound from brown algae, was found to increase docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (ARA, 20:4n-6) in the liver of mice. DHA and ARA are known to be biosynthesized from the respective precursor α-linolenic acid (ALA, 18:3n-3) and linoleic acid (LNA, 18:2n-6), through desaturation and chain elongation. We examined the effect of FX on the fatty acid metabolism in HepG2 cells (Hepatocellular carcinoma, human). In the first experiment, cells were co-treated with ALA (100 µM) and FX (0-100 µM) or vehicle for 48 h. FX increased eicosapentaenoic acid (EPA, 20:5n-3), docosapentaenoic acid (DPA, 22:5n-3), DHA at concentrations of ≥ 50 µM. To clarify the change in the metabolism of polyunsaturated fatty acid (PUFA), in the second experiment, cells were co-treated with universally-[(13)C]-labeled (U-[(13)C]-) ALA (100 µM) and FX (100 µM) for 0.5, 3, 6, 24 and 48 h. [(13)C] labeled-EPA, DPA and DHA content in HepG2 cells were all increased by FX after 48 h treatment. Furthermore, estimated delta-5 desaturase (D5D) but not delta-6 desaturase (D6D) activity index was increased at 48 h. These results suggested that FX may enhance the conversion of ALA to longer chain n-3 PUFA through increasing D5D activity in the liver.

Inhibitory effects of wild bitter melon leaf extract on Propionibacterium acnes-induced skin inflammation in mice and cytokine production in vitro.

Propionibacterium acnes is a key pathogen involved in acne inflammation. Wild bitter melon (WBM, Momordica charantia L. var. abbreviate Seringe) is consumed as both a vegetable and as folk medicine in Taiwan. We examined the inhibitory activity of the total phenolic extract (TPE) of WBM leaf on P. acnes-induced inflammatory responses in vivo and in vitro. Our data showed that TPE significantly attenuated P. acnes-induced ear swelling in mice along with microabscess. Flow cytometry analysis revealed that TPE treatment significantly decreased the migration of neutrophils and interleukin (IL)-1ß(+) populations in vivo. In P. acnes-stimulated human monocytic THP-1 cells, TPE suppressed the mRNA levels and production of IL-8, IL-1ß, and tumor necrosis factor (TNF)-αin vitro. In addition, TPE suppressed P. acnes-induced matrix metalloproteinase-9 levels. TPE blocked nuclear factor-κB (NF-κB) activation and inactivated mitogen-activated protein kinases (MAPK); these actions may partially account for its inhibitory effect on cytokine production. The quantitative HPLC analysis revealed gallic, chlorogenic, caffeic, ferulic, and cinnamic acids, myricetin, quercetin, luteolin, apigenin, and thymol in TPE. All these phenolics significantly suppressed P. acnes-induced IL-8 production in vitro. Our results suggest that WBM leaf extract effectively inhibits P. acnes-induced inflammatory responses and may be useful to relieve the inflammation of acne.

The up-regulation of hepatic acyl-CoA oxidase and cytochrome P450 4A1 mRNA expression by dietary oxidized frying oil is comparable between male and female rats.

We previously demonstrated that oxidized frying oil (OFO) activates peroxisome proliferator-activated receptor alpha (PPARalpha) and up-regulates hepatic acyl-CoA oxidase (ACO) and cytochrome P450 4A1 (CYP4A1) genes in male rats. As female rats were shown to be less responsive to some peroxisome proliferators (PP), this study compared the expression of a few PPARalpha target genes in male and female rats fed diets containing OFO. Male and female rats were fed a diet containing 20 g/100 g OFO (O diet) or fresh soybean oil (F diet) for 6 wk. Both male and female rats fed the O diet showed significantly higher liver weight, hepatic ACO and catalase activities, CYP4A protein, and expression of ACO and CYP4A1 mRNA (P < 0.05) compared with their control groups. The mRNA expression of two other PPARalpha target genes, FA-binding protein and HMG-CoA synthase, were marginally increased by dietary OFO (P = 0.0669 and 0.0521, respectively). Female rats fed the O diet had significantly lower CYP4A protein than male rats fed the same diet. The remaining OFO-induced effects were not significantly different between male and female rats fed the O diet. These results indicate that dietary OFO, unlike clofibrate or other PP, had minimal sexual dimorphic effect on the induction of hepatic PPARalpha target gene expression.

Wild bitter gourd protects against alcoholic fatty liver in mice by attenuating oxidative stress and inflammatory responses.

Bitter gourd (Momordica charantia L.) is a common vegetable grown widely in Asia that is used as a traditional medicine. The objective of this study was to investigate whether wild bitter gourd possessed protective effects against chronic alcohol-induced liver injury in mice. C57BL/6 mice were fed an alcohol-containing liquid diet for 4 weeks to induce alcoholic fatty liver. Meanwhile, mice were treated with ethanol extracts from four different wild bitter gourd cultivars: Hualien No. 1', Hualien No. 2', Hualien No. 3' and Hualien No. 4'. The results indicated that the daily administration of 500 mg kg body weight(-1) of a Hualien No. 3' extract (H3E) or a Hualien No. 4' extract (H4E) markedly reduced the steatotic alternation of liver histopathology. In addition, the activation of serum aminotransferases (AST and ALT) and the accumulation of hepatic TG content caused by alcohol were ameliorated. The hepatoprotective effects of H3E and H4E involved the enhancement of the antioxidant defence system (GSH, GPx, GRd, CAT and SOD), inhibition of lipid peroxidation (MDA) and reduction of pro-inflammatory cytokines (TNF-α, IL-1ß and IL-6) in the liver. Moreover, H3E and H4E supplementation suppressed the alcohol-induced elevation of CYP2E1, SREBP-1, FAS and ACC protein expression. These results demonstrated that ethanol extracts of Hualien No. 3' and Hualien No. 4' have beneficial effects against alcoholic fatty liver, in which they attenuate oxidative stress and inflammatory responses.

Antioxidant, cell-protective, and anti-melanogenic activities of leaf extracts from wild bitter melon (Momordica charantia Linn. var. abbreviata Ser.) cultivars.

BACKGROUND: Several wild bitter melon (WBM; Momordica charantia Linn. var. abbreviata Ser.) cultivars were developed in Taiwan. However, little information is available regarding biological function of WBM leaf. Therefore, the objectives of this study were to investigate the nutrient content, antioxidant, cell protection and anti-melanogenic properties of wild bitter melon leaf. RESULTS: Methanolic leaf extracts were prepared from a variety and two cultivars of WBM. All extracts exerted potent nitric oxide and hydroxyl radical scavenging capacities. Furthermore, all extracts effectively reduce the production of reactive oxygen species and prevent cell death in UVB-irradiated HaCaT keratinocytes. The cell protective effect of leaf extract was also investigated by the prevention of HaCaT cells from sodium nitroprusside or menadione-induced toxicity, and significant cyto-protective activities were observed for all of them. Additionally, all extracts significantly suppressed tyrosinase activity and melanin levels in B16-F10 melanocytes. CONCLUSIONS: WBM leaf extract showed significant antioxidant, cyto-protective and anti-melanogenic activities. These findings suggested that WBM leaves may be beneficial for preventing the photo-oxidative damage and melanogenesis of skin.