Inhibitory effects of ethanolic extracts of Boussingaultia gracilis on the spasmogen-induced contractions of the rat isolated gastric fundus

Anti-obesity effects of Boussingaulti gracilis Miers var. pseudobaselloides Bailey via activation of AMP-activated protein kinase in 3T3-L1 cells

In a previous study, we demonstrated the anti-obesity and hypolipidemic effects of Boussingaulti gracilis Miers var. pseudobaselloides Bailey in high-fat diet-induced obese rats. The present study investigated the molecular mechanisms by which B. gracilis Miers var. pseudobaselloides Bailey ethanol extract (BGE) conferred antidifferentiation and anti-adipogenic effects in the 3T3-L1 preadipocyte differentiation model. BGE treatment significantly and dose-dependently suppressed lipid accumulation and down-regulated the expression of major transcription factors involved in adipogenesis, such as peroxisome proliferator-activated receptor-γ, CCAAT/enhancer binding protein α, sterol regulatory element-binding proteins, and their target genes. It is important that treatment with BGE increased phosphorylation of AMP-activated protein kinase (AMPK), which is one of the rate-limiting enzymes in the fatty acid synthesis pathway, and its direct downstream protein, acetyl-coenzyme A carboxylase. These results suggest that BGE may exert anti-adipogenic effects through regulation of AMPK activity and expression of genes involved in lipogenesis.

Ancordin, the major rhizome protein of madeira-vine, with trypsin inhibitory and stimulatory activities in nitric oxide productions

Anredera cordifolia (Ten.) Steenis, or the synonymous name of Boussingaultia baselloides or Boussingaultia gracilis var. pseudobaselloides, is a South American species of ornamental succulent vine, commonly known as the madeira-vine. The fresh leaves of madeira-vine are frequently used as vegetables. A. cordifolia is an evergreen climber that grows from fleshy rhizomes. The rhizome contained one major (23kDa) protein band under non-reducing condition in the SDS-PAGE. The first 15 amino acids in the N-terminal region of the major protein band (23kDa), named tentatively ancordin, were KDDLLVLDIGGNPVV which were highly homologous to sequences of winged bean seed protein ws-1, Medicago truncatula proteinase inhibitor, soybean trypsin inhibitor, and sporamin. By using activity stains, the ancordin showed trypsin inhibitory activity in the SDS-PAGE gel which was found not only in rhizomes but also in aerial tubers, but few in fresh leaves. The crude extracts from rhizomes of madeira-vine were directly loaded onto trypsin-Sepharose 4B affinity column. After washing with 100mM Tris-HCl buffer (pH 7.9) containing 100mM NaCl, the ancordin was eluted directly by 0.2M KC1-HC1 buffer (pH 2.0). In calculation, the purified protein exhibited 0.0428mug trypsin inhibition/mug ancordin (corresponding to 0.53 unit of TPCK-treated trypsin inhibited/mug ancordin). The purified ancordin was used to evaluate the nitric oxide productions in RAW264.7 cells in the presence of polymyxin B (poly B, 50microg/ml) to eliminate the lipopolysaccharide (LPS) contaminations. It was found that ancordin (1.25-5microg/ml) could dose-dependently (R=0.954) stimulate the nitric oxide (NO) productions (expressed as nitrite concentrations) in RAW264.7 cells without significant cytotoxicity, and kept the similar effects in NO production in 6.25microg/ml ancordin.

Evaluation of the cytotoxicity, mutagenicity and antimutagenicity of emerging edible plants

This study evaluates the toxic, mutagenic and antimutagenic effects of emerging edible plants that are consumed as new leafy vegetables in Taiwan. Among eight plant extracts, only the extracts of Sol (Solanum nigrum L.) showed cytotoxicity to Salmonella typhimurium TA100 in the absence of S9 mix. The toxicity of extracts from different parts of the Sol plant, such as leaf and stem, immature fruit and mature fruit, towards S. typhimurium TA100 and human lymphocytes was also assayed. The immature fruit extracts of Sol exhibited strong cytotoxicity with dose dependence and induced significant DNA damage in human lymphocytes based on the comet assay. However, no mutagenicity was found in eight plant extracts to TA98 or TA100 either with or without the S9 mixture. Sol and Sec [Sechium edule (Jacq.) Swartz] extracts showed the strongest inhibitory effect towards the mutagenicity of 2-amino-3-methyl-imidazo[4,5-f]quinoline (IQ) in S. typhimurium TA98 and TA100; the ID(50) was less then 1 mg/plate. Cra [Crassocephalum creidioides (Benth.) S. Moore] extracts also expressed moderate antimutagenic activities towards IQ and benzo[a]pyrene (B[a]P) either in TA98 or in TA100; the ID(50) was 1.63-2.41 mg/plate. The extracts from Bas (Basella alba L.), Bou (Boussingaultia gracilis Miers var. pseudobaselloides Bailey), Cen (Centella asiatica L. Urban), Cor (Corchorus olitorius L.) and Por (Portulaca oleracea L.) showed weak to moderate inhibition of mutagenicity of IQ. However, the potential antimutagenicity of these plant extracts towards B[a]P was weaker than that towards IQ. For a direct mutagen, 4-nitroquinoline-N-oxide (NQNO), only the Sol extracts showed strong inhibitory effects in the TA100 system. The antimutagenic activity of water extracts of Sec was partly reduced by heating at 100 degrees C for 20 min. The heat-stable antimutagens in Sec extracts could be produced in the plant extract preparation process. Fractions with molecular weights above 30,000 showed the strongest antimutagenicity and peroxidase activity in all the fractions of the Sec extracts.