Mealworm larvae (Tenebrio molitor L.) exuviae as a novel prebiotic material for BALB/c mouse gut microbiota.

The objective of this study was to evaluate the effect of yellow mealworm (Tenebrio molitor L.) exuviae (ME) given as a prebiotic in 20% of the diet fed to BALB/c mice. Analysis of the ME revealed that it was mostly composed of crude protein (52.94%), crude fiber (10.70%), and moisture (10.54%). When ME was fed to mice for 8 weeks, the number of intestinal lactic acid bacteria increased, reaching similar numbers (4.50 ± 0.80 CFU/mL) to those (4.70 ± 0.80 CFU/mL) of the control group not fed ME. Microbiome analysis showed that 8 weeks feeding of ME promoted the growth of Bifidobacteriaceae and Lactobacillaceae compared to the POS group, indicating the positive effects of feeding 20% ME on the intestinal microbiota of mice. These results suggest that ME can be considered as a dietary prebiotics to improve human gut microbial population, but further application study to human is necessary.

Characterization of Lactobacillus plantarum strains isolated from black raspberry and their effect on BALB/c mice gut microbiota.

The objective of this study was to evaluate probiotic effects of two Lactobacillus plantarum strains (GBL16 and 17) isolated from black raspberry. Results revealed that the number of GBL16 was gradually decreased as bile salt concentration was increased from 0.3 to 1%. However, GBL17 did not show any difference when GBL17 was applied to 1% bile salt, and it indicates that GBL17 is more tolerant to bile salt than GBL16. GBL17 exhibited higher heat resistance and adhesion ability to Caco-2 cells than GBL16. Regarding gut microbiome, no significant change in the number of total bacteria in intestines of mice after treatment with GBLs was determined. However, the combination of GBL16 and GBL17 significantly increased the number of total bacteria in intestines of mice after they were orally administered. Therefore, the results suggest that both GBL16 and 17 strains could be one of major probiotics that can improve human gut health.

Two new lignans from the roots of Pulsatilla koreana.

Two new lignans, (2 R,3 R)-2 ß-(4''-hydroxy-3''-methoxybenzyl)-3 α-(4'-hydroxy-3'-methoxybenzyl)-γ-butyrolactone 2-O-( ß-D-glucopyranoside) (1) and (1 S,2 R,3 S)-dimethyl-1,2,3,4-tetrahydro-3,6,7-trihydroxy-1-(3',4'-dihydroxyphenyl)naphthalene-2,3-dicarboxylate (2) together with nine known compounds (3-11) were isolated from the ethyl acetate fraction of the roots of Pulsatilla koreana. Their chemical structures were established based on physicochemical and spectroscopic data analyses. All isolates were investigated for their inhibition effects against the classical pathway of the complement system. Among them, compound 6 showed significant inhibitory activity with an IC (50) value of 75.9 µM, compounds 8 and 9 had moderate effects with IC (50) values of 182.2 and 166.5 µM, respectively.

Alkaloids from roots of Stephania rotunda and their cholinesterase inhibitory activity.

In the course of screening plants used in folk medicine as memory enhancers, a 70% ethanolic extract of Stephania rotunda roots showed significant AChE inhibitory activity. Repeated column chromatography led to the isolation of a new protoberberine alkaloid, which we named stepharotudine (1), and seven known compounds (2-8). The chemical structures of the isolated compounds were elucidated based on extensive 1D and 2D NMR spectroscopic data. Compounds 1-8 were investigated in vitro for their anticholinesterase activity using a rat cortex AChE enzyme.

Oleanane-type triterpenoids from Aceriphyllum rossii and their cytotoxic activity.

The hexane-soluble fraction of the roots of Aceriphyllum rossii was used to isolate seven new oleanane-type triterpenoids, aceriphyllic acids C-I (1-7), together with seven known triterpenoids. The structures of aceriphyllic acids C-I were determined as 3alpha-hydroxyolean-12-en-23,29-dioic acid (1), 3beta-hydroxyolean-12-en-23,29-dioic acid (2), 3beta,23-dihydroxyolean-12-en-29-oic acid (3), 3alpha-O-acetylolean-12-en-23,27-dioic acid (4), 3alpha-O-caffeoylolean-12-en-27-oic acid (5), 3alpha-O-acetylolean-12-en-23,29-dioic acid (6), and 3alpha-hydroxyolean-12-en-23-al-27-oic acid (7) by spectroscopic analyses. In the evaluation of the in vitro cytotoxicity of these compounds against the MCF-7 and LLC cancer cell lines, compounds 10 and 13 exhibited cytotoxic activity against the LLC cancer cell line with IC(50) values of 7.63 and 6.56 microM, respectively.

Protein tyrosine phosphatase 1B inhibitory by dammaranes from Vietnamese Giao-Co-Lam tea.

ETHNOPHARMACOLOGICAL RELEVANCE: Gynostemma pentaphyllum (Thunb.) tea was used in Vietnamese folk medicine as anti-diabetic agent. AIM OF THE STUDY: This study was aimed to investigate the inhibitory activities of fractions and constituents isolated from Gynostemma pentaphyllum on protein tyrosine phosphatase 1B (PTP1B) since it has been proposed as a treatment therapy for type 2 diabetes and obesity. MATERIALS AND METHODS: The 70% EtOH extract, CHCl3 fraction, EtOAc fraction, BuOH fraction, and seven isolated dammarane triterpenes were evaluated for their inhibitory activity in protein phosphatase enzymes (PTP1B and VHR). RESULTS: CHCl3-soluble fraction showed a dose-dependent inhibitory activity of the PTP1B enzyme with the IC50 value of 30.5 microg/mL. Among seven tested compounds, compounds 6 showed the most potent PTP1B inhibitory activity with IC50 value of 5.3+/-0.4 microM compared to a range 15.7-28.5 microM for the other six compounds. The inhibition mode of 6 was competitive toward p-NPP with a K(i) value of 2.8 microM. CONCLUSION: These study results suggested that the PTP1B inhibitory activity of these dammaranes may enable this plant to play an important role in the treatment of diabetes.

Identification of ADP-ribosylation factor 4 as a suppressor of N-(4-hydroxyphenyl)retinamide-induced cell death.

Yeast-based functional screening for inhibitors of Bcl-2-associated X protein (Bax)-induced cell death in yeast identified ADP-ribosylation factor 4 (ARF4) as a novel anti-apoptotic gene in human glioblastoma-derived U373MG cells. Yeast or U373MG cells that overexpressed ARF4 exhibited reduced reactive oxygen species (ROS) generation in response to Bax or N-(4-hydroxyphenyl)retinamide (4-HPR), respectively, which suggests that ROS play a role in the inhibition of cell death by ARF4. The 4-HPR-mediated phosphorylation of c-JUN N-terminal kinase, p38, and extracellular signal-regulated kinase was markedly suppressed in U373MG cells that stably expressed ARF4. Stable ARF4 transfectants were also refractory to 4-HPR-induced mitochondrial translocation of Bax, release of mitochondrial cytochrome c, and activation of caspase-3. Our results suggest that ARF4 participates in the regulation of glioblastoma apoptosis through the inhibition of stress-mediated apoptotic signals.

Antioxidative flavonoids from Cleistocalyx operculatus buds.

Four new flavonoids, 3'-formyl-4',6',4-trihydroxy-2'-methoxy-5'-methylchalcone (1), 3'-formyl-6',4-dihydroxy-2'-methoxy-5'-methylchalcone 4'-O-beta-D-glucopyranoside (2), (2S)-8-formyl-6-methylnaringenin (3), and (2S)-8-formyl-6-methylnaringenin 7-O-beta-D-glucopyranoside (4) were isolated from the buds of Cleistocalyx operculatus (Myrtaceae). The structures of the new metabolites (1-4) were determined on the basic of spectroscopic analyses including 2 dimensional NMR. Compounds 1 and 3 exhibited 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity with IC(50) values of 22.8 and 27.1 microM, respectively.

Ran suppresses paclitaxel-induced apoptosis in human glioblastoma cells.

Yeast-based functional screening of a human glioblastoma cDNA library identified ras-related nuclear protein (Ran) as a novel suppressor of Bcl-2-associated X protein (Bax), a pro-apoptotic member of the Bcl-2 family of proteins. Yeast cells that expressed human Ran were resistant to Bax-induced cell death. In U373MG glioblastoma cells, stable overexpression of Ran significantly attenuated apoptotic cell death induced by the chemotherapeutic agent paclitaxel. FACS analysis demonstrated that Ran is involved in paclitaxel-induced cell cycle arrest. Stable overexpression of Ran also markedly inhibited the phosphorylation of Bcl-2 by paclitaxel, and inhibited the translocation of Bax, the release of cytochrome c and activation of caspase-3. Paclitaxel-induced phosphorylation of c-JUN N-terminal kinase (JNK), but not p38, extracellular signal-regulated kinase and Akt, was markedly suppressed in U373MG cells that stably expressed Ran. These results suggest that Ran suppresses paclitaxel-induced cell death through the downregulation of JNK-mediated signal pathways.

Identification of cytochrome c oxidase subunit 6A1 as a suppressor of Bax-induced cell death by yeast-based functional screening.

Human cytochrome c oxidase subunit VIa polypeptide 1 (COX6A1) was identified as a novel suppressor of Bcl-2-associated X protein (Bax)-mediated cell death using yeast-based functional screening of a mammalian cDNA library. The overexpression of COX6A1 significantly suppressed Bax- and N-(4-hydroxyphenyl)retinamide (4-HPR)-induced apoptosis in yeast and human glioblastoma-derived U373MG cells, respectively. The generation of reactive oxygen species (ROS) in response to Bax or 4-HPR was inhibited in yeast and U373MG cells that expressed COX6A1, indicating that COX6A1 exerts a protective effect against ROS-induced cell damage. 4-HPR-induced mitochondrial translocation of Bax, release of mitochondrial cytochrome c, and activation of caspase-3 were markedly attenuated in U373MG cells that stably expressed COX6A1. Our results demonstrate that yeast-based functional screening of human genes for inhibitors of Bax-sensitivity in yeast identified a protein that not only suppresses the toxicity of Bax in yeast, but also has a potential role in protecting mammalian cells from 4-HPR-induced apoptosis.

Involvement of nuclear factor kappaB in up-regulation of aldose reductase gene expression by 12-O-tetradecanoylphorbol-13-acetate in HeLa cells.

To elucidate the molecular mechanisms underlying the up-regulation of aldose reductase observed in many cancer cells, we investigated the signal transduction pathways mediating induction of aldose reductase gene expression by 12-O-tetradecanoylphorbol-13-acetate, a potent tumor promoter. A maximum of four-fold induction in aldose reductase mRNA was demonstrated in HeLa cells treated with 12-O-tetradecanoylphorbol-13-acetate. The increased level of aldose reductase transcript was accompanied by the elevated level of enzyme activity, and completely abolished in the presence of actinomycin D. Inhibitors of protein kinase C, bisindolylmaleimide I and calphostin C, as well as inhibitors of tyrosine kinase, genistein and tyrphostin A23, significantly attenuated 12-O-tetradecanoylphorbol-13-acetate-induced increase in aldose reductase mRNA. Blockade of the p38 mitogen-activated protein kinase pathway by SB203580 also suppressed 12-O-tetradecanoylphorbol-13-acetate-induced aldose reductase expression. The promoter activity of aldose reductase gene was significantly augmented in the cells treated with 12-O-tetradecanoylphorbol-13-acetate, but attenuated in the presence of bisindolylmaleimide I, tyrphostin A23 or SB203580. Pyrrolidinedithiocarbamate, a nuclear factor kappaB inhibitor, dose-dependently suppressed 12-O-tetradecanoylphorbol-13-acetate-induced increase in aldose reductase mRNA. 12-O-tetradecanoylphorbol-13-acetate augmented the DNA binding activity of nuclear factor kappaB and nuclear factor kappaB-dependent gene transcription, and these effects were attenuated by bisindolylmaleimide I or tyrphostin A23, but not by SB203580. Taken together, activation of protein kinase C and tyrosine kinase by 12-O-tetradecanoylphorbol-13-acetate elicits increased promoter activity of aldose reductase gene via nuclear factor kappaB. A p38 mitogen-activated protein kinase pathway, distinct from the tyrosine kinase pathway, may also take part in 12-O-tetradecanoylphorbol-13-acetate-induced increase in aldose reductase gene expression.