Isolation of 8-hydroxyglycitein and 6-hydroxydaidzein from soybean miso

We isolated from soybean miso 8-hydroxyglycitein and 6-hydroxydaidzein as DPPH-radical scavengers, and elucidated their chemical structures by mass spectrometric, and (1)H- and (13)C-NMR spectrosopic analyses. These compounds showed DPPH-radical scavenging activity as high as that of alpha-tocopherol, 8-hydroxygenistein and 8-hydroxydaidzein. This is the first report of the isolation of 8-hydroxyglycitein from a natural source.     

1,1-Diphenyl-2-picrylhydrazyl radical-scavenging compounds from soybean miso and antiproliferative activity of isoflavones from soybean miso toward the cancer cell lines

Guided by their DPPH radical-scavenging activity, nine compounds were isolated from soybean miso. Of these, 8-hydroxydaidzein, 8-hydroxygenistein and syringic acid had as high DPPH radical-scavenging activity as that of alpha-tocopherol. The antiproliferative activity of four of the isolated isoflavones toward three cancer cell lines was examined. 8-Hydroxygenistein showed the highest activity (IC50=5.2 microM) toward human promyelocytic leukemia cells (HL-60).     

Antimutagenic activity of flavonoids from Chrysanthemum morifolium

A methanol extract from the flower heads of Chrysanthemum morifolium showed a suppressive effect on umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK1002 against the mutagen 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (furylfuramide). The methanol extract was re-extracted with hexane, chloroform, ethyl acetate, butanol, and water. The ethyl acetate fraction showed a suppressive effect. Suppressive compounds in the ethyl acetate fraction were isolated by silica gel column chromatography and identified as the flavonoids acacetin (1), apigenin (2), luteolin (3), and quercetin (4) by EI-MS, IR, and (1)H and 13C NMR spectroscopy. Compounds 1-4 suppressed the furylfuramide-induced SOS response in the umu test. Compounds 1-4 suppressed 60.2, 75.7, 90.0, and 66.6% of the SOS-inducing activity at a concentration of 0.70 micromol/ml. The ID50 (50% inhibitory dose) values of 1-4 were 0.62, 0.55, 0.44, and 0.59 micromol/ml. These compounds had the suppressive effects on umu gene expression of the SOS response against other mutagens, 4-nitroquinolin 1-oxide (4NQO) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), which do not require liver-metabolizing enzymes. These compounds also showed the suppression of SOS-inducing activity against the other mutagens aflatoxin B1 (AfB1) and 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), which require liver-metabolizing enzymes, and UV irradiation. In addition to the antimutagenic activities of these compounds against furylfuramide, Trp-P-1 and activated Trp-P-1 were also assayed by the Ames test using S. typhimurium TA100.     

Antimutagenic and anticarcinogenic activity of tea polyphenols

Tea is the most popular beverage, consumed by over two thirds of the world's population. Tea is processed differently in different parts of the world to give green (20%), black (78%) or oolong tea (2%). Green tea is consumed mostly in Japan and China. The antimutagenic and anticarcinogenic activities of green tea are extensively examined. The chemical components of green and black tea are polyphenols, which include EC, ECG, EGC, EGCG and TFs. This article reviews the epidemiological and experimental studies on the antimutagenicity and anticarcinogenicity of tea extracts and tea polyphenols. In Japan, an epidemiological study showed an inverse relationship between habitual green tea drinking and the standardized mortality rates for cancer. Some cohort studies on Chanoyu (Japanese tea ceremony) women teachers also showed that their mortality ratio including deaths caused by malignant neoplasms were surprisingly low. The antimutagenic activity against various mutagens of tea extracts and polyphenols including ECG and EGCG has been demonstrated in microbial systems (Salmonella typhimurium and Escherichia coli), mammalian cell systems and in vivo animal tests. The anticarcinogenic activity of tea phenols has been shown in experimental animals such as rats and mice, in transplantable tumors, carcinogen-induced tumors in digestive organs, mammary glands, hepatocarcinomas, lung cancers, skin tumors, leukemia, tumor promotion and metastasis. The mechanisms of antimutagenesis and anticarcinogenesis of tea polyphenols suggest that the inhibition of tumors may be due to both extracellular and intracellular mechanisms including the modulation of metabolism, blocking or suppression, modulation of DNA replication and repair effects, promotion, inhibition of invasion and metastasis, and induction of novel mechanisms.     

Antimutagenic activity of extracts from anticancer drugs in Chinese medicine

The antimutagenic activities of extracts of 36 commonly used anticancer crude drugs from Chinese herbs were studied by using the Salmonella/microsomal system in the presence of picrolonic acid or benzo[a]pyrene to test whether they contain direct or indirect antimutagens. Each crude drug was extracted with boiling water for 2 h, the method which is commonly used by Chinese people to prepare the drug for oral intake. The extracts of Pteris multifida P. showed the highest antimutagenic activity against picrolonic acid-induced mutation. The extracts of 6 other different kinds of Chinese herbs were shown to have a moderate antimutagenic activity against picrolonic acid-induced mutation, and they are: Actinidia chinensis P., Artemisia lavendulaefolia DC. and Crotalaria sessiflora L., Prunella vulgaris L., Paris polyphylla S. and Ampelopsis brevipedunculata T. The extracts of Smilax china L., Prunella vulgaris L. and Actinidia chinensis P. were demonstrated to inhibit the mutagenicity of benzo[a]pyrene completely. The 12 other kinds of extracts of Chinese herbs which had a moderate antimutagenic activity against benzo[a]pyrene were: Pteris polyphylla S., Ampelopsis brevipedunculata T., Duchesnea indica F., Gossypium herbaceum L., Lithospermum erythrorrhizon SZ., Artemisia lavendulaefolia DC., Selaginella doederleinii H., Dianthus superbus L., Centipeda minima ABA., Curcuma zedoaria R., Marsdenia tenacissima WA. and Kalopanax septemlobus K. Among them, there were 5 kinds of crude drugs, Actinidia chinensis P., Artemisia lavendulaefolia DC., Prunella vulgaris L., Paris polyphylla S. and Ampelopsis brevipedunculata T., containing antimutagenic factors against both picrolonic acid- and benzo[a]pyrene-induced mutation.     

Antimutagenic activity of green tea polyphenols

For centuries green tea has been a widely consumed beverage throughout the world. It is known to contain a number of pharmacologically active compounds. In this study water extracts of green tea (WEGT) and their major constituents, green tea polyphenols (GTP), were examined for antimutagenic activity. WEGT and GTP were found to significantly inhibit the reverse mutation induced by benzo[alpha]pyrene (BP), aflatoxin B1 (AFB1), 2-aminofluorene, and methanol extracts of coal tar pitch in Salmonella typhimurium TA100 and/or TA98 in the presence of a rat-liver microsomal activation system. GTP also inhibited gene forward mutation in V79 cells treated with AFB1 and BP, and also decreased the frequency of sister-chromatid exchanges and chromosomal aberrations in V79 cells treated with AFB1. The addition of GTP during and after nitrosation of methylurea resulted in a dose-dependent inhibition of mutagenicity. Studies to define the mechanism of the antimutagenic activity of GTP suggest that it may affect carcinogen metabolism, DNA adduct formation, the interaction of ultimate carcinogen or the scavenging of free radicals.     

Antimutagenic activity of wheat beta-purothionin Tk-AMP-BP

Antimutagenic activity on human RD cells was studied for beta-purothionin Tk-AMP-BP isolated from seeds of wheat Triticum kiharae, which has a higher stress resistance. Cadmium chloride at 5 x 10(-6) M was used as a mutagen. The numbers of DNA breaks in mutagen-treated and intact cells were inferred from the single-stranded to double-stranded DNA ratio and expressed as protection coefficients. The protective effect was simultaneously assayed for aqueous plant extracts known to possess antioxidant properties. Wheat thionin was the most active among all of the antimutagens examined; its protection coefficient reached 85-88% at micromolar peptide concentrations (8-32 microg/ml). Thus, wheat beta-purothionin was for the first time demonstrated to be highly efficient in protecting human cell DNA from the damaging effect of cadmium chloride.     

Antimutagenic and antioxidant/prooxidant activity of quercetin

The present study has been performed to evaluate the antimutagenic activity of quercetin, ascorbic acid and their combination against an oxidative mutagen. An effort was also made to correlate this activity to the in vitro antioxidant activity of these agents. Antimutagenicity testing was done in Ames Salmonella Assay system using Salmonella typhimurium TA102 against t-butylhydroperoxide as an oxidative mutagen. In vitro antioxidant scavenging activity was tested for DPPH free radical, superoxide anion, hydrogen peroxide and hydroxyl radical in their specific test systems. Quercetin (0.5-8 nmole/plate) and ascorbic acid (0.1-100 micromole/plate) showed significant effect. Quercetin (4 and 8 nmole/plate) when combined with ascorbic acid (500 nmole/plate) showed an increase in the antimutagenic activity. In vitro antioxidant activity of quercetin was better than ascorbic acid in all the test systems used. The study indicated that the antimutagenic activity of quercetin was not solely accountable by its antioxidant nature. However, in vitro free radical scavenging activity of quercetin correlated well with the antimutagenic activity.     

Antimutagenic activity of mitochondria-targeted plastoquinone derivative

The ability of cationic plastoquinone derivative 10-(6′-plastoquinonyl) decyltriphenylphosphonium (SkQ1) to modify processes of spontaneous and induced mutagenesis was studied. It is shown that daily introduction of this compound into male Wistar rats in doses of 25 and 250 nmol/kg during two weeks decreases spontaneous level of chromosome aberrations in anaphase in the eye cornea from 0.39 ± 0.09 to 0.13 ± 0.08 and 0.14 ± 0.05, respectively. The level of 8-hydroxy-2′-deoxyguanosine in blood serum of the investigated animals decreases from 32.12 ± 1.55 to 25.90 ± 2.26 and 25.76 ± 1.50 ng/ml, respectively. These facts indicate that the decrease in spontaneous clastogenesis is caused by decreased level of DNA damage by endogenous reactive oxygen species. A higher dose of SkQ1 also decreases to control level chromosome aberrations caused by oxygen under pressure of 0.5 MPa for 60 min. It is also shown in experiments with bacterial biosensors that SkQ1 is able to efficiently protect cells against genotoxic effect of UV radiation at 300–400 nm.     

Antimutagenic activity of new analogues of fluphenazine

Fluphenazine (FPh) exhibited antimutagenic activity in lymphocyte cultures, markedly decreasing genotoxic effects of standard mutagenic agents present in cell cultures. However, the strong pharmacological activity of this neuroleptic drug, together with its serious side effects on the central nervous system, limits its use as an antimutagenic compound. In this paper we describe a route of chemical synthesis of FPh analogues that are more hydrophilic than the model compound, thus probably penetrate more weakly through the blood-brain barrier. These new analogues were tested for their antimutagenic and pro-apoptotic activities in human lymphocyte cultures, genotoxically damaged in vitro with benzo[a]pyrene [40 microM, 30 min] and subsequently cultured for 48 h in the presence of the tested compounds. The fluphenazine analogues enhanced apoptosis in genotoxically damaged lymphocytes more strongly than the model compound did. The increase of apoptotic cell frequency was the highest with compound 4a [2-(trifluoromethyl)-10-[3-(diethanolamino)-2-hydroxypropyl] phenothiazine]--a 35% higher effect than that of fluphenazine. The cytotoxicity of derivative 4a was the lowest among the tested compounds; it was 60% lower than that of fluphenazine. The antimutagenic effect of 4a was about 10% stronger than that of fluphenazine. Compound 4a also had the highest hydrophilicity of the new FPh analogues. Compound 4a was chosen for further study as a potentially usable antimutagen that would only weakly penetrate the central nervous system.     

Antimutagenic activity of dextran gammaphos derivatives]

In experiments with V-79 Chinese hamster cell culture the influence of dextran gammaphos derivatives on the mutagenic effects of gamma-radiation was studied by the number of cells with micronuclei and fragmented nuclei. Products of interaction between gammaphos and dialdehyde dextran were shown to have a higher antimutagenic activity than gammaphos.     

Antimutagenic activity of wheat β-purothionin Tk-AMP-BP

Antimutagenic activity on human RD cells was studied for β-purothionin Tk-AMP-BP isolated from seeds of wheat Triticum kiharae, which has high stress resistance. Cadmium chloride at 5 × 10⁻⁶ M was used as a mutagen. The numbers of DNA breaks in mutagen-treated and intact cells were inferred from the single-stranded to double-stranded DNA ratio and expressed as protection coefficients. The protective effect was simultaneously assayed for aqueous plant extracts known to possess antioxidant properties. Wheat thionin was the most active among all of the antimutagens examined; its protection coefficient reached 85–88% at micromolar peptide concentrations (8–32 μg/ml). Thus, wheat β-purothionin was for the first time demonstrated to be highly efficient in protecting human cell DNA from the damaging effect of cadmium chloride.     

Antimutagenic activity of Lactobacillus plantarum KLAB21 isolated from kimchi Korean fermented vegetables

Antimutagenic activity of Lactobacillus plantarum KLAB21, isolated from Korean kimchi, was investigated against MNNG (N-methyl-N-nitro-N-nitrosoguanidine), NQO (4-nitroquinoline-1-oxide), NPD (4-nitro-O-phenylenediamine) and aflatoxin B1 using Salmonella typhimurium strains TA100 and TA98. Although all the cell fractions including the culture supernatant, dry cells and cell-free extract exhibited antimutagenic activity against MNNG and NQO, the culture supernatant possessed the highest activity. The antimutagenic ratio of the culture supernatant was 98.4% against MNNG on strain TA100 and 57.3% against NQO on strain TA98. Its antimutagenic activity was reconfirmed by a Bacillus subtilis spore-rec assay. Levels of the antimutagenic ratios of other lactic acid bacteria originating from fermented milk ranged between 26.8 to 53% against MNNG and 28.5 to 43.4% against NQO. The antimutagenic activities of the strain KLAB21 against NPD were 72.6% on TA100 and 62.8% on TA98, and those against aflatoxin B1 were 82.5% on TA100 and 78.2% on TA98.     

大豆转录因子基因GmMYBJ6的表达及功能分析

MYB转录因子是最大的植物转录因子家族之一, 对植物的生长发育及生理代谢具有重要的调节作用。GmMYBJ6 (GenBank登录号: DQ902863)是从大豆中分离克隆的新的MYB转录因子基因, 本文对其在植物中的表达及功能进行了初步研究。利用Norhern杂交对GmMYBJ6在不同组织中的表达情况进行了检测, 结果只在叶片中检测到了GmMYBJ6的表达; 酵母表达结果显示, GmMYBJ6具有明显的转录激活功能, b－半乳糖苷酶活性为28.48 U/mL; 构建绿色荧光蛋白融合表达载体, 基因枪法转化洋葱表皮细胞进行瞬时表达, 结果表明, GmMYBJ6蛋白定位于细胞核中; 半定量RT-PCR检测结果显示, 在转化烟草中, GmMYBJ6的表达可提高类黄酮代谢途径中的苯丙氨酸氨基裂解酶(PAL)、肉桂酸-4-羟化酶(C4H)、4-香豆酰辅酶A连接酶(4CL)、查尔酮合成酶(CHS)、黄酮醇合成酶(FLS)等关键酶的表达, 并且使烟草中总黄酮的含量增加; 此外, 在紫外辐射、高盐及干旱(PEG)等处理下, 大豆品种吉林3号中GmMYBJ6的表达量明显增加, 显示GmMYBJ6对非生物胁迫具有明显的应答反应。     

Antimutagenic activity of the novel antileukemic agents, avarone and avarol

The two antileukemic agents, avarone and avarol, were determined to be neither direct nor indirect mutagenic agents in the Ames microsomal test. Moreover, the two sesquiterpenoid compounds drastically reduced the mutagenic effect of benzo[a]pyrene in the same system. Subsequent enzymic studies demonstrated that avarone and avarol are powerful inhibitors of benzo[a]pyrene monooxygenase.     

Antimutagenic activity of methanolic extracts of four ayurvedic medicinal plants

Methanolic extracts of Acorus calamus (Rhizome), Hemidesmus indicus (Stem), Holarrhena antidysenterica (Bark) and Plumbago zeylanica (Root), were tested for their antimutagenic potential. These extracts, at tested concentrations, showed no sign of mutagenicity to Salmonella typhimurium tester strains. The extracts of the plants exhibited varying level of antimutagenicity. At a dose of 100 microg/plate, the extracts exhibited the inhibition of His+ revertants from 18.51% to 82.66% against direct acting mutagens, methyl methanesulphonate (MMS) and sodium azide (NaN3) induced mutagenicity in Salmonella tester strains TA 97a, TA 100, TA 102 and TA 104. However, at lower concentrations (25 and 50 mcirog/plate) of the plant extracts, a decrease in antimutagenic activity was recorded. Dose dependent antimutagenic activity of the extracts is also evident from linear regression analysis of the data. The over all antimutagenic potential of above four extracts was found to be in order of A. calamus > H. indicus > H. antidysenterica > P. zeylanica. Further, total phenolic content of these extracts did not correlate with its antimutagenic activity in A. calamus and P. zeylanica.