The antimutagenic activity of biomass extracts from the cultured cells of medicinal plants in the Ames test

Antimutagenic activity of 20 and 40% ethanol extracts from the biomass of Rhodiola rosea, Polyscias filicifolia, Panax ginseng and Ungernia victoris cultured cells have been studied. DDDTDP, ethidium bromide, benz(a)pyrene, benzidine served as model mutagens for Salmonella typhimurium TA 98 strain (the latter two were tested in presence of metabolic activation system); for S. typhimurium TA 100 strain these were tio-tefa, bichromate potassium and sodium azide and heavy metal compounds (chlorides of manganese, zinc, cadmium, lead acetate) for both strains. Higher capacity of the extracts from the biomass of R. rosea and P. filicifolia to counteract gene mutations induced by various mutagens was demonstrated (ca. 90% inhibition in isolated cases). In the experiment with the metabolic activation most effective proved to be the extracts from the P. ginseng biomass (up to 34% and 47% mutagenicity inhibition).     

Ginseng extract exhibits antimutagenic activity against induced mutagenesis in various strains of Salmonella typhimurium

Ginseng has been reported to exhibit antioxidant and antimutagenic activity. The present study was undertaken with a view to confirm whether the antioxidant activity of Ginseng is responsible for its antimutagenic action. The concentrated root extract of Panax ginseng (Ginseng extract I) and its lyophilized powder (Ginseng extract II) obtained from two different manufacturing houses, were tested against mutagenesis using the well-standardized Ames microsomal test system. The extracts exhibited antimutagenic effect against hydrogen peroxide induced mutagenesis in TA100 strain, and against mutagenesis produced by 4-nitroquinoline-N-oxide in both TA98 and TA100 strains of Salmonella typhimurium. Both the extracts failed to show any antimutagenic potential against tert-butyl hydroperoxide (an oxidative mutagen) in TA102 strain, a strain highly sensitive to active oxygen species. The extracts also indicated a weak antioxidant activity in a series of in vitro test systems viz., 1,1-diphenyl picryl hydrazyl (DPPH) assay, hydrogen peroxide scavenging and superoxide anion scavenging. The results indicate that the protective effects shown by ginseng extract(s) against 4-nitroquinoline-n-oxide and hydrogen peroxide induced mutagenesis in TA98 and TA100 could mainly be due to its property to initiate and promote DNA repair rather than free radical scavenging action.     

Effect of adaptogens on the activity of the pituitary-adrenocortical system in rats

Intraperitoneal injection of Panax ginseng C. A. Mey tincture, Polyscias filicifolia Bailey tincture, Panax ginseng tincture or Eleutherococcus Maxim extract to rats produced a rise in plasma corticosterone 1 hour after the treatment. Immobilization-induced rise in plasma corticosterone was increased by 7-day pretreatment with any agent. Thus, the adaptation effect of Panax ginseng C. A. Mey and Polyscias filicifolia Bailey is probably realized through the pituitary-adrenocortical system.     

Antioxidative effects of Cinnamomi cassiae and Rhodiola rosea extracts in liver of diabetic mice

Both Cinnamomi cassiae and Rhodiola rosea extracts are used as anti-diabetic folk medicines. Recently, increased oxidative stress was shown to play an important role in the etiology and pathogenesis of diabetes mellitus and its complications. This study was designed to examine the effects of Cinnamomi cassiae and Rhodiola rosea extracts on blood glucose, lipid peroxidation, the level of reduced glutathione and its related enzymes (glutathione reductase, glutathione S-transferase), and the activity of the antioxidant enzymes (catalase, superoxide dismutase and glutathione peroxidase) in the liver of db/db mice. Diabetic C57BL/Ks db/db mice were used as experimental models. Mice were divided into control (n=10), Cinnamomi cassiae (200 mg/kg/day, n=10), and Rhodiola rosea (200 mg/kg/day, n=10) treated groups for 12 weeks of treatment. These type II diabetic mice were used to investigate the effects of Cinnamomi cassiae and Rhodiola rosea on blood glucose, reduced glutathione, glutathione reductase, glutathione S-transferase, glutathione peroxidase, lipid peroxidation, catalase and superoxide dismutase. Cinnamomi cassiae and Rhodiola rosea extracts significantly decreased on blood glucose, increased levels of reduced glutathione and the activities of glutathione reductase, glutathione S-transferase, glutathione peroxidase, catalase and superoxide dismutase in the liver. Extract treatment also significantly decreased lipid peroxidation. Cinnamomi cassiae and Rhodiola rosea extracts may be effective for correcting hyperglycemia and preventing diabetic complications.     

红景天提取物提高高强度跑台运动小鼠的抗氧化能力

为了考察红景天提取物对高强度跑台运动小鼠的抗氧化能力的影响,本研究将30只昆明小鼠随机分成对照组、模型组和红景天提取物组,每组10只。红景天提取物组小鼠按照500 mg/kg bw的剂量灌胃红景天提取液(2 m L)。对照组和模型组小鼠灌胃等体积的蒸馏水,共灌胃4周。采用硫酸蒽酮比色法检测小鼠肝脏和肌肉组织糖原的含量;采用硫代巴比妥酸比色法检测小鼠骨骼肌组织中的丙二醛(MDA)水平;采用RT-PCR和Western blotting检测骨骼肌组织中的超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和过氧化氢酶(CAT)的表达水平;采用苏木精和伊红(HE)染色评价骨骼肌病理改变。研究显示,模型组小鼠的跑台运动时间显著低于红景天提取物组(61.32 min vs 83.22 min,p<0.05);与模型组相比,红景天提取物组小鼠骨骼肌的炎性细胞浸润明显减轻,肌纤维排列明显改善;红景天提取物组的肝糖原和肌糖原含量均显著高于模型组;红景天提取物组小鼠骨骼肌组织中的MDA水平显著低于模型组;红景天提取物组的SOD、GSH-Px和CAT m RNA和蛋白表达水平均显著高于模型组;红景天提取物可通过上调抗氧化酶表达来增加抗氧化能力,减弱骨骼肌损伤,并增加机体的抗疲劳能力。     

Rhodiola rosea as antioxidant in red blood cells: ultrastructural and hemolytic behaviour

Rhodiola rosea L. (Crassulaceae) is a plant that lives at high altitude in Europe and Asia, widely used for its high capacity to increase the organism resistance to different stress conditions. Although a few international literature supports these effects, today R. rosea has become a common component of many dietary supplements also in the Western world. The aim of the present study was to investigate the effect of the R. rosea roots aqueous extract on in vitro human erythrocytes exposed to hypochlorous acid (HOCl)-oxidative stress. Several damages occur in human erythrocytes exposed in vitro to HOCl, among these membrane protein and lipid modifications, shifting from the discocyte shape to the echinocyte one, and determining lysis ultimately. Therefore, in the present work, the evaluation of the antioxidant capacity of the Rhodiola extract has been carried out by means of scanning electron microscopy and of hemolytic behaviour on human erythrocytes exposed to HOCl in the presence of increasing doses of the aqueous extract in different experimental environments (co-incubation and subsequent incubations). The results obtained are consistent with a significant protection of the extract in presence of the oxidative agent, but a cautionary note emerges from the analysis of the data related to the cell exposition to the plant extract in the absence of any induced oxidative stress. In fact, the addition to erythrocyte of high doses of R. rosea extract always determines severe alterations of the cell shape.     

Interaction of plant extracts of <Emphasis Type="Italic">Ungernia victoris,Rhodiola rosea</Emphasis>, and <Emphasis Type="Italic">Polyscias filicifolia</Emphasis> with a bacterial cell

Components of three investigated plant extracts from the biomass of cultivated cells of Ungernia victoris, Rhodiola rosea, and Polyscias filicifolia interact with porin proteins OmpC and OmpF and reduce their receptor activity towards OmpC- and OmpF-dependent bacteriophages. The influx of these components into cells optimizes the synthesis of a lipopolysaccharide (LPS) complex and contributes to the enhancement of receptor activity of not only LPS but also OmpA and LamB proteins closely associated with the latter.     

不同中药复方及不同提取方法提取液对小鼠耐缺氧作用的影响

目的:探讨不同中药处方组成及其不同提取方法的复方提取物对小鼠耐缺氧能力的影响,以优选其处方组成和制备提取方法。方法:将雄性BALB/c小鼠随机分成6组：空白对照组、复方丹参组、复方红景天醇-水提取组(红景天、黄芪、黄精、枸杞子)、复方红景天水提取组、复方黄芪醇-水提取组(黄芪、黄精、枸杞子)、复方黄芪水提取组,每组30只,每组小鼠连续灌胃给药10 d,空白组灌胃灭菌注射用水,复方丹参组0.15 g/kg,复方红景天醇-水提取组和水提取组3 g/kg,复方黄芪醇-水提取组和水提取组1.7 g/kg。各组于末次灌胃1 h后进行常压耐缺氧实验、亚硝酸钠中毒存活实验和急性脑缺血缺氧实验,并测定小鼠脑组织氧化应激相关抗氧化物酶活性和代谢物含量。结果:与空白对照组相比,复方丹参组、复方黄芪醇-水提取组和水提取组常压耐缺氧存活时间均显著延长(P<0.01),脑缺血缺氧后张口喘气次数均显著增加(P<0.05)。各组注射亚硝酸钠后存活时间没有统计学差异。与空白对照组相比,复方黄芪水提取组T-AOC、SOD、GSH和CAT活性均显著升高(P<0.05,P<0.01),MDA含量均显...     

Selective inhibition of Escherichia coli recBC activities by plasmid-encoded GamS function of phage lambda

The gam locus of bacteriophage lambda encompasses two coding sequences with the same reading frame and translational stop, one corresponding to an Mr 11646 polypeptide (gamS gene), the other to an Mr 16349 polypeptide (gamL gene). A DNA segment encoding gamS but not gamL was placed under lambda pR promoter control (regulated by the cIts857-coded repressor) on a multicopy plasmid, and an insertion mutation (gamS201) was constructed. Expression of gamS+, but not gamS201, inhibited Escherichia coli RecBC nuclease in vivo; the criteria were inhibition of chromosomal DNA degradation after UV irradiation and plating of T4 gene 2- phages. The recB+ C+ bacteria expressing gamS+ were completely or partially similar to recC- mutants with respect to certain phenotypes: defective plating of phages P1 and P2, ability to plate (in a recA- background) lambda red- gam- phages, reduced resistance to UV irradiation, defective SOS induction, decreased colony-forming ability.     

Development of a novel method of lytic phage delivery by use of a bacteriophage P22 site-specific recombination system

Bacteriophage therapy represents a potential alternative to the use of antibiotics to control proliferation of pathogenic bacteria. As an alternative to the strategy where a limited number of doses of large numbers of lytic bacteriophages are administered, a novel method delivery system was developed so that phages are continually released into the culture. Specifically, a non-pathogenic Escherichia coli strain was constructed that was lysogenic for a lytic mutant of bacteriophage lambda. This lysogen was shown to be effective at decreasing the number of lambda-sensitive E. coli in vitro. Construction of this E. coli strain was accomplished by development of a plasmid-based system utilizing the site-specific recombination machinery of bacteriophage P22 to integrate DNA constructs into the host chromosome. This recombination system is useful for strain construction and other genetic manipulations in both E. coli and Salmonella enterica serovars.     

Serotonin involvement in Rhodiola rosea attenuation of nicotine withdrawal signs in rats

Rhodiola rosea has been used for centuries in the traditional medicine to stimulate nervous system, to enhance physical and mental performance and to treat fatigue. It is known that administration of Rhodiola rosea extract elicits antidepressant activity, but the mechanism of action still remains unclear. Evidence from animal models and human studies show that nicotine reduces symptoms of depression and that nicotine cessation induces depressive-like symptoms. We investigated the effects of Rhodiola rosea on nicotine withdrawal signs. Nicotine dependence was induced by subcutaneous nicotine injection (2mg/kg, four times daily) for 14 days. Another group of animals treated with nicotine (for 14 days) and successively with Rhodiola rosea extract was co-administered with selective 5-HT receptorial antagonist WAY 100635 (1mg/kg). After nicotine withdrawal animals were evaluated for behavioural parameters (locomotor activity, abstinence signs, marble burying test), diencephalic serotonin metabolism and serotonin receptor-1A expression. Results show a significant increase of 5-HT content in N treated with R. rosea, with a significant increase of serotonin receptor 1A, suggesting an involvement of serotonin in beneficial effects of R. rosea on suffering produced by nicotine withdrawal.     

Spontaneous lambda OR mutations suppress inhibition of bacteriophage growth by nonimmune exclusion phenotype of defective lambda prophage.

Survivor clones with defects in gene functions that participate in the replicative killing of thermally induced Escherichia coli constructs with integrated lambda N through P or cIII through P gene fragments were selected at a frequency of about 10(-6). Among the population of survivors, clones were identified that exhibited normal lambda immunity at 30 degrees C, as shown by their ability to prevent the plating of lambda wild type and to support the plating of a nearly identical heteroimmune bacteriophage lambda imm434. However, when placed at 42 degrees C to inactivate the cIts857 repressor, these survivor isolates excluded the plating of both lambda wild-type and lambda imm434 phages, a phenotype designated nonimmune exclusion (Nie). Spontaneous mutants of lambda wild type were isolated that overcame the Nie phenotype and would plaque at 42 degrees C on cell lawns of these isolates. The acquired lambda se mutations suppressed nonimmune exclusion, prevented lysogenization by interrupting repressor expression from PRM, and made the phage insensitive to replicative inhibition. The se mutations were genetically mapped and sequenced within the rightward lambda operator site.     

In vitro transposition of transposon Tn3

Transposition of the ampicillin-resistant transposon Tn3 was reproduced in vitro using the Escherichia coli cell extract. In this cell-free system, we used plasmid DNA carrying mini-Tn3 as donor and phage lambda DNA as target and assayed for ampicillin-resistance transducing phages formed by cointegration of these DNA molecules. Ampicillin-resistance transducing phages, which were obtained by in vitro packaging of lambda DNA after the in vitro transposition reaction, were formed only in the presence of Tn3 transposase. The reaction required mini-Tn3 with the proper sequence and orientation of the terminal inverted repeats of Tn3. The reaction also required DNA synthesis but not RNA synthesis by E. coli RNA polymerase.     

Transposition of lambda placMu is mediated by the A protein altered at its carboxy-terminal end

Lambda placMu phages are derivatives of bacteriophage lambda that use the transposition machinery of phage Mu to insert into chromosomal and cloned genes. When inserted in the proper fashion, these phages yield stable fusions to the Escherichia coli lac operon in a single step. We have determined the amount of DNA from the c end of phage Mu present in one of these phages, lambda placMu3, and have shown that this phage carries a 3137-bp fragment of Mu DNA. This DNA segment carries the Mu c-end attachment site and encodes the Mu genes cts62, ner+, and gene A lacking 179 bp at its 3' end (A'). The product of this truncated gene A' retains transposase activity and is sufficient for the transposition of lambda placMu. This was demonstrated by showing that lambda placMu derivatives carrying the A am1093 mutation in the A' gene are unable to transpose by themselves in a Su- strain, but their transposition can be triggered by coinfection with lambda pMu507(A+ B+). We have constructed several new lambda placMu phages that carry the A' am1093 gene and the kan gene, which confers resistance to kanamycin. Chromosomal insertions of these new phages are even more stable than those of the previously reported lambda placMu phages, which makes them useful tools for genetic analysis.     

In vivo effects of Panax ginseng extracts on the cytochrome P450-dependent monooxygenase system in the liver of 2,3,7,8-tetrachlorodibenzo-p-dioxin-exposed guinea pig

The effects of the subchronic administration of Panax ginseng extracts were examined on the hepatic cytochrome P450-dependent monooxygenase system of guinea pigs pre-exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Panax ginseng extracts were intraperitoneally administered to guinea pigs at 100 mg/kg/day for 14 days from 1 week after a single intraperitoneal injection of 1 microg of TCDD/kg of body weight. TCDD treatment increased the total cytochrome P450 content 2.86-fold, and this was remarkably inhibited by the administration of Panax ginseng extracts. Treatment with ginseng extract alone also decreased the contents of cytochrome P450 by 33%, but both TCDD and ginseng extracts had no effect on cytochrome b(5) content. The administration of TCDD resulted in a 1.73-fold increase in microsomal NADPH-cytochrome P450 reductase activity in the guinea pig liver, and this was significantly inhibited by ginseng extracts, but treatment with ginseng extracts alone had no effect on its activity, and no statistical changes in the activity of NADPH-cytochrome b(5) reductase were observed in guinea pig liver due to TCDD and/or ginseng extract administration. Compared to the control, ECOD activity remarkably (1.76-fold) increased after TCDD administration, but this increase was completely inhibited by treatment with ginseng extract. Treatment with ginseng extract alone resulted in a 50% reduction of ECOD activity. TCDD administration remarkably induced benzphetamine demethylation (BPDM) activity, while ginseng extract also slightly increased the enzyme's activity, but the induction attributed to ginseng extracts was not statistically significant. Even though administration of ginseng extracts slightly inhibited TCDD-induced BPDM activity, the inhibition was not statistically significant. These results indicate that ginseng extract exerts different effect on the induction of P450 isozymes. From these results, we suggest that Panax ginseng extracts may act as an inhibitor of CYP1A rather than that of CYP2B.     

Gene Regulation in N Mutants of Bacteriophage λ

Mutants (N(-)nin) of bacteriophage lambda in which the N gene product is not required for growth on wild-type Escherichia coli do not plate on recA bacterial mutants. Secondary mutants, selected for growth on recA, lie within the immunity region to the right of gene cI and appear identical to the cro mutants of Eisen et al. In an N(+) phage, a cro mutation causes enhanced and prolonged production of lambda exonuclease. N(-)cro phages make no detectable exonuclease, but show an increased rate of specific excision from lysogens and are excluded by P2 prophage. These properties, together with the ability to plate on recA, suggest that N(-)cro phages express genes to the left of N at a rate that is very low but higher than that for N(-)cro(+) phages. N(-)nin phages can integrate at the normal site on the bacterial chromosome, but specific excision from lysogens is immeasurably low.     

Initiation of lambda DNA replication in vitro promoted by isolated P-gene product.

The product of the P gene of bacteriophage lambda was isolated from heat-induced lambda-lysogenic Escherichia coli cells. It was found to bind to DNA, to be devoid of nuclease activity acting on double-stranded lambda DNA and of nicking/closing activity. Initiation of lambda DNA replication promoted by the P-gene product in a complementation assay in vitro was sensitive to rifampicin. Sedimentation analysis of the products and their hybridization to separated lambda DNA strands indicate that lambda DNA was formed in a reaction similar to ring-to-ring replication in vivo. The reaction was symmetric from the beginning, i.e. both lambda DNA strands were copied without delay.     

纳米银/植物源复合抗菌剂的制备及其抑菌性能的研究

以硝酸银作为银源,水溶性淀粉作保护剂,丙酮酸钠作还原剂,氨水提供碱性环境来制备纳米银胶,并以聚乙烯吡咯烷酮(PVP)作分散稳定剂,复配红景天提取液和无患子提取液制备出纳米银/植物源复合抗菌剂。实验结果表明,纳米银胶或植物提取液仅对部分细菌或霉菌有较强抑制效果,而复合抗菌剂对细菌、霉菌均有很强抑制效果。在湿巾液中添加0.5%复合抗菌剂时,其对大肠杆菌,金黄色葡萄球菌和白色念珠菌的抗菌效率可达99%,且经过常温六个月、高温55℃一个月保存后,其抗菌活性分别可达到95%、90%左右,表明复合抗菌剂具有较强的抗菌效率及抗菌稳定性。     

Stationary phase-like properties of the bacteriophage λ Rex exclusion phenotype

The rex genes of bacteriophage lambda were found to protect lysogenic Escherichia coliK host cells against killing by phage T4 rII, when compared in parallel to isogenic Rex(-) lysogens and nonlysogens. This protective effect was abrogated upon mutation of the host stationary-phase sigma factor RpoS. Rex(+) lysogens infected by T4 rII contracted, formed aggregates and shed flagella, thus resembling cells entering stationary phase. These phenotypes were accentuated in nonlysogenic cells carrying multicopy plasmids expressing rexA-rexB: cells were about two-fold contracted in length, expressed membrane-bound and detached flagella, were insensitive to infection by a variety of phages and clumped extensively; in addition, cultures of these cells were odorous. Our observations support the hypothesis that the Rex system can cause a stationary-phase-like response that protects the host against infection by T4 rII.