三种百合鳞茎提取物的抑菌作用

采用纸片琼脂扩散法测定了宜昌百合、岷江百合及兰州百合鳞茎甲醇提取物对革兰氏阳性细菌(金黄色葡萄球菌、枯草芽孢杆菌)和革兰氏阴性细菌(大肠杆菌、沙门氏菌)的抑制活性,并对3种百合鳞茎提取物的含量与抑菌活性进行了剂量-效应关系分析。结果表明:3种百合鳞茎提取物对4种细菌均具有抑制活性,对革兰氏阳性细菌的抑菌活性高于对革兰氏阴性细菌的抑菌活性,且宜昌百合和岷江百合两种野生百合鳞茎提取物的抑菌活性均高于普通食用的兰州百合;3种百合鳞茎提取物的含量与抑菌活性之间存在明显的剂量-效应关系,即随着提取物含量的升高,抑菌活性明显升高。     

The detection of promutagen activation by extracts of cells expressing cytochrome P450IA2 cDNA: preincubation dramatically increases revertant yield in the Ames test

Two slightly different protocols, the plate incorporation method and the preincubation method, are used in the Ames Salmonella mutagen test. Using a preincubation method, we recently demonstrated efficient activation of a number of food-derived promutagens by extracts of mammalian cells expressing cDNAs of rat-liver cytochrome P450IA2 and of a P450IA2-IA1 hybrid. We report here that, for 2-amino-3,4-dimethylimidazo[4,5-ƒ]quinoline (MeIQ), 1-aminoanthracene and several other promutagens, preincubation dramatically increased the number of revertant colonies in the Ames test when extracts of cytochrome P450IA2-containing transfected cells or low concentrations of rat-liver extracts were used as the source of activating enzymes. At higher concentrations of rat-liver extract protein, the effect of preincubation was less pronounced. The effect of preincubation was not due to the low protein concentrations in the assays since increasing the total protein concentration did not abolish the requirement for preincubation for the detection of MeIQ activation at low concentrations of rat-liver extract. In experiments where P450IA2 synthesized in transfected cells in culture is used to study promutagen activation, the plate incorporation protocol may seriously underestimate the capacity of cell extracts to activate promutagens. Thus, interlaboratory comparisons become difficult and unnecessarily large quantities of cell extract protein may be needed to detect promutagen activation. Whenever Ames test assays are carried out under conditions where P450 concentration limits revertant yield, it would be prudent to examine both the preincubation and plate incorporation protocol.     

The detection of promutagen activation by extracts of cells expressing cytochrome P450IA2 cDNA: preincubation dramatically increases revertant yield in the Ames test.

Two slightly different protocols, the plate incorporation method and the preincubation method, are used in the Ames Salmonella mutagen test. Using a preincubation method, we recently demonstrated efficient activation of a number of food-derived promutagens by extracts of mammalian cells expressing cDNAs of rat-liver cytochrome P450IA2 and of a P450IA2-IA1 hybrid. We report here that, for 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 1-aminoanthracene and several other promutagens, preincubation dramatically increased the number of revertant colonies in the Ames test when extracts of cytochrome P450IA2-containing transfected cells or low concentrations of rat-liver extracts were used as the source of activating enzymes. At higher concentrations of rat-liver extract protein, the effect of preincubation was less pronounced. The effect of preincubation was not due to the low protein concentrations in the assays since increasing the total protein concentration did not abolish the requirement for preincubation for the detection of MeIQ activation at low concentrations of rat-liver extract. In experiments where P450IA2 synthesized in transfected cells in culture is used to study promutagen activation, the plate incorporation protocol may seriously underestimate the capacity of cell extracts to activate promutagens. Thus, interlaboratory comparisons become difficult and unnecessarily large quantities of cell extract protein may be needed to detect promutagen activation. Whenever Ames test assays are carried out under conditions where P450 concentration limits revertant yield, it would be prudent to examine both the preincubation and plate incorporation protocol.     

Analytical processing of binary mixture information by olfactory bulb glomeruli

Odors are rarely composed of a single compound, but rather contain a large and complex variety of chemical components. Often, these mixtures are perceived as having unique qualities that can be quite different than the combination of their components. In many cases, a majority of the components of a mixture cannot be individually identified. This synthetic processing of odor information suggests that individual component representations of the mixture must interact somewhere along the olfactory pathway. The anatomical nature of sensory neuron input into segregated glomeruli with the bulb suggests that initial input of odor information into the bulb is analytic. However, a large network of interneurons within the olfactory bulb could allow for mixture interactions via mechanisms such as lateral inhibition. Currently in mammals, it is unclear if postsynaptic mitral/tufted cell glomerular mixture responses reflect the analytical mixture input, or provide the initial basis for synthetic processing with the olfactory system. To address this, olfactory bulb glomerular binary mixture representations were compared to representations of each component using transgenic mice expressing the calcium indicator G-CaMP2 in olfactory bulb mitral/tufted cells. Overall, dorsal surface mixture representations showed little mixture interaction and often appeared as a simple combination of the component representations. Based on this, it is concluded that dorsal surface glomerular mixture representations remain largely analytical with nearly all component information preserved.     

The effect of age, season and growth conditions on anti-inflammatory activity in Eucomis autumnalis (Mill.) Chitt. Plant extracts

Eucomis (Family Hyacinthaceae) bulbs are greatly valued in traditionalmedicine for the treatment of a variety of ailments, predominantly thoseinvolving pain, fever and inflammation. The COX-1 assay was used to screenethanolic extracts prepared from the dried leaves, bulbs and roots of E. autumnalis (subspecies autumnalis) to determine the variation ofanti-inflammatory activity with age and season of harvest. Young plantswere found to have large amounts of COX-1 inhibitory activity, particularlyin the leaves. As the plant matured, greater activity was associated with thebulb and root extracts. The anti-inflammatory activity of the leaf, bulb androot extracts varied slightly throughout the year, with the greatest levelsdetected towards the end of the growing season, shortly before the onsetof dormancy. A seaweed application (Kelpak) decreased the anti-inflammatory activity of the leaf, bulb and root extracts, while increasedtemperature/increased light intensity had no significant effect on theCOX-1 inhibitory activity of the leaf extracts. The bulb extracts fromtreated plants harvested towards the end of the growing season showed asignificant decrease in anti-inflammatory activity, while the anti-inflammatory activity of the corresponding not root extracts increased.     

Tyrosinase activity and the expression of the agouti gene in the mouse

Tyrosinase activity at the time of phaeomelanin synthesis in neonatal mice is lower in agouti than in black skin and hair bulb tissue, and this depressed activity is associated with a reduction in the electrophoretically distinct de novo form of the enzyme. Direct chemical measurements of sulphydryl compounds show elevated levels in agouti hair bulb tissue at this stage of development. The addition of exogenous copper to hair bulb extracts raises the activity of tyrosinase in agouti to approximately the black level but has no affect on black itself. These results are discussed in relation to the role of sulphydryl compounds and copper availability in regulating tyrosinase activity and turnover.     

Polymorphisms of the DNA repair gene XRCC1 and the frequency of somatic mutations at the glycophorin A locus in newborns

Essential oils extracted from the three medicinal plants; Helichrysum italicum, Ledum groenlandicum and Ravensara aromatica, together with their mixture were tested for their genotoxic and antigenotoxic activities against urethane, a well-known promutagen. We have adopted the somatic mutations and recombination test (SMART) in the wings of Drosophila melanogaster. Three days old larvae, trans-heterozygous for two genetic markers mwh and flr, were treated by essential oil and/or urethane. A negative control corresponding to solvent was also used. Our results do not show any significant effect of the oils tested but they reduce the mutation ratio resulting from urethane. The mixture of the three oils at equal volume seems to be the most effective. The antimutagenic effect of these oils could be explained by the interaction of their constituents with cytochrome P-450 activation system leading to a reduction of the formation of the active metabolite. The effect could also be attributed to certain molecules that are involved in these oils.     

A comparison of the pharmacological properties of garden cultivated and muthi market-sold Bowiea volubilis

Biological activities of petroleum ether (PE), dichloromethane (DCM), 70% ethanol (EtOH) and water extracts of Botanical Garden-grown (BG) and muthi market-sourced (MM) Bowiea volubilis bulbs were compared. Bulb extracts were subjected to the microdilution technique using five test organisms for antimicrobial activity and cyclooxygenase (COX-1 and -2) inhibition as well as the Ames test for potential mutagenicity. Overall, both the MM and BG bulb extracts demonstrated a comparatively weak antimicrobial potency. The best minimum inhibitory concentration (MIC: 1.56 mg/ml) was detected in the MM bulb water extract against Candida albicans. In both MM and BG bulbs, 63% of the extracts, particularly the non-polar solvent extracts, exhibited a high (> 70% inhibition) COX-1 and -2 inhibitory activity. Both MM and BG bulb extracts were not mutagenic against the Salmonella typhimurium TA98 tester strain. Current findings indicate the potential substitution of cultivated B. volubilis bulbs (BG) for the wild population (MM) which is often utilized and preferred in traditional medicine. Inevitably, this will contribute to the conservation of the species as the strain on the wild population due to overharvesting will be alleviated.     

Cytosolic activation of 2-aminoanthracene: implications in its use as diagnostic mutagen in the Ames test.

The metabolic activation of 2-aminoanthracene to mutagens in the Ames test was investigated using hepatic S9, microsomal and cytosolic fractions from control and Aroclor 1254-treated rats as activation systems. Microsomal and S9 preparations from control animals could activate 2-aminoanthracene, but the efficiency of activation was suppressed by pretreatment of animals with Aroclor 1254. Cytosolic fractions from Aroclor 1254-treated rats could readily activate the promutagen more readily than microsomes. The cytosolic activation of 2-aminoanthracene required NADPH and could not be accounted for by possible microsomal contamination. The molybdenum oxygenases appear not to contribute to the cytosolic activation of this promutagen. It is concluded that (a) the microsomal activation of 2-aminoanthracene is catalysed more effectively by enzyme systems other than the P450 I family and (b) an enzyme system capable of activating this carcinogen in vitro is present in the hepatic cytosol. The implications of these findings in the use of 2-aminoanthracene as a positive control in the Ames test are discussed.     

The effect of humic acids,fractionated according to molecular mass,on the formation and mutagenicity of N-methyl-N-nitrosourea

Fractions of humic acids (HA-K⁺) of molecular mass between 500 and 300 000 and exceeding 300 000 showed a very high nitrite depleting ability, whereas the fraction of HA-K⁺ with molecular mass lower than 500 had little or no such effect. Autoclaving HA-K⁺ (121 °C, 20 min) decreased the nitrite-depleting ability to about a half. This observation correlates with the results of mutagenic studies in Arabidopsis thaliana, demonstrating the inhibitory effect of HA-K⁺ and its fractions on the formation of mutagenic N-methyl-N-nitrosourea (MNU) from the nitrosation mixture of N-methylurea and nitrite. Nonfractionated HA-K⁺ had no inhibitory effect towards the mutagenic activity of preformed direct acting MNU or towards the activation of the promutagen N-nitrosodimethylamine to a mutagenic product.     

Variation in economically and ecologically important traits in onion plant organs during reproductive development

The spatial distribution of organosulphur compounds throughout the onion (Allium cepa L.) plant body during reproduction is of ecological and horticultural interest. These secondary metabolites are associated with both pest resistance and many of the vegetable's culinary and medicinal properties, including the ability to inhibit platelet aggregation. Inhibition of platelet aggregation can be of benefit to human cardiovascular health. Organosulphur compound concentrations are associated with elemental sulphur, pungency, soluble solids and effect on human platelet aggregation. These parameters were evaluated in extracts collected separately from bulb scales, leaf blades, scapes and umbels biweekly throughout the reproductive phase of the life cycle of the onion. Significant variation in pungency, platelet inhibition, total sulphur content and soluble solids existed among samples of organs and within organs over time during reproductive growth. Furthermore, some extracts from leaf, scape and bulb induced rather than inhibited platelet aggregation.     

Configurational and Elemental Odor Mixture Perception Can Arise from Local Inhibition

Contrast enhancement via lateral inhibitory circuits is a common mechanism in sensory systems. We here employ a computational model to show that, in addition to shaping experimentally observed molecular receptive fields in the olfactory bulb, functionally lateral inhibitory circuits can also mediate the elemental and configurational properties of odor mixture perception. To the extent that odor perception can be predicted by slow-timescale neural activation patterns in the olfactory bulb, and to the extent that interglomerular inhibitory projections map onto a space of odorant similarity, the model shows that these inhibitory processes in the olfactory bulb suffice to generate the behaviorally observed inverse relationship between two odorants' perceptual similarities and the perceptual similarities between either of these same odorants and their binary mixture.     

Genotoxicity and antigenotoxicity of some essential oils evaluated by wing spot test of Drosophila melanogaster

Essential oils extracted from the three medicinal plants; Helichrysum italicum, Ledum groenlandicum and Ravensara aromatica, together with their mixture were tested for their genotoxic and antigenotoxic activities against urethane, a well-known promutagen. We have adopted the somatic mutations and recombination test (SMART) in the wings of Drosophila melanogaster. Three days old larvae, trans-heterozygous for two genetic markers mwh and flr, were treated by essential oil and/or urethane. A negative control corresponding to solvent was also used. Our results do not show any significant effect of the oils tested but they reduce the mutation ratio resulting from urethane. The mixture of the three oils at equal volume seems to be the most effective. The antimutagenic effect of these oils could be explained by the interaction of their constituents with cytochrome P-450 activation system leading to a reduction of the formation of the active metabolite. The effect could also be attributed to certain molecules that are involved in these oils.     

Epidermal enzyme-mediated mutagenicity of the skin carcinogen, 2-aminoanthracene

Using four Salmonella typhimurium tester strains (TA1537, TA1538, TA98 and TA100) and the promutagen 2-aminoanthracene, an epidermal S9-mediated mutagenicity assay was developed. Using an activation mixture derived from whole skin of the rat, mutagenicity was observed in tester strain TA98 whereas an activation mixture derived from the dermis resulted in mutagenicity in tester strains TA1538, TA98 and TA100. Activation mixtures from both the epidermis and the liver produced a positive response in all of the tester strains studied. Activation mixtures from liver were shown to have the highest specific activity followed in decreasing order of potency by epidermis, dermis and whole skin. These results indicate that the skin, a target tissue directly exposed to environmental chemicals, is capable of converting 2-aminoanthracene to mutagenic moieties. Since the skin of the rat is known to be susceptible to tumor induction by 2-aminoanthracene our findings re-emphasize that membrane-bound enzymes can influence toxic responses including mutagenicity to xenobiotics in cutaneous tissue.     

组织培养暗紫贝母的药理作用

以组织培养的暗紫贝母为材料,野生暗紫贝母为对照,用不同溶剂提取,得４个化学组人 生物碱部分,总皂甙部分,水溶性部分和脂溶性部分,并以生药粉为阳性对照进行药效学试验。结果表明：组培贝母与野生贝母有相似的止咳、祛痰作用;总皂甙部分与总生物碱部分均为川贝有效活性成分,ｔ得之间无显著性差异;经ＴＬＣ是乌头总生物碱部分与总皂甙部分无化学成分重叠。     

Effect of application of different concentrations and appropriate schedules of aqueous garlic (Allium sativum L.) bulb extracts against Maruca vitrata and Clavigralla tomentosicollis on cowpea,Vigna unguiculata (L.) Walp

Abstract

Three concentrations (5, 10 and 20% w/v) and spraying schedules (2×, 4× and 6× weekly applications) of garlic, Allium sativum L. bulb extracts were assayed for efficacy against Maruca vitrata Fab. and Clavigralla tomentosicollis Stal. on cowpea under rain fed conditions in two seasons. The results showed that application of aqueous garlic bulb extracts at all the treatment levels significantly (p < 0.05) reduced the populations of the target pests compared with the untreated check. Application of 10 and 20% garlic bulb extracts with 4 or 6 weekly applications gave better control of these pests, protected the pods from damage and increased grain yields on treated cowpea compared with 5% extract at all three application schedules and were comparable to the synthetic insecticide treatment. This material could play a role in the integrated management of M. vitrata and C. tomentosicollis on cowpea fields managed by limited resource farmers in developing countries. The plant material is readily available, cheap, safe, non phytotoxic and technologically simple to use.     

Transsynaptic Regulation of Olfactory Bulb Catecholamines in Mice and Rats

Norepinephrine (NE), dopamine (DA), 3,4-dihydroxyphenylalanine (DOPA), and 3,4-dihydroxyphenylacetic acid (DOPAC) were measured simultaneously by high performance liquid chromatography with electrochemical detection in extracts of olfactory bulbs at various intervals after chemical or surgical deafferentation. Chemical deafferentation of mice by intranasal irrigation with Triton X-100 or of rats by olfactory axotomy resulted in a rapid progressive decline of DA and DOPAC and an associated rise in NE in the olfactory bulb. However, after several weeks, these values returned to prelesion levels concomitant with reinnervation of the bulb by the afferent neurons. In contrast, deafferentation by procedures known to prevent reinnervation of the bulb by the afferent chemoreceptor neurons (i.e., a ZnSo4 solution in mice or a surgical procedure in rats) completely blocked the return to pre-lesion values of DA, DOPAC, and NE. The specificity of these effects was demonstrated by the inability of intranasal administration of the neurotoxin 6-hydroxydopamine to alter DA levels, resulting instead in a significant decline in olfactory bulb NE content. These data demonstrate that the DA content of the olfactory bulb can be influenced by either chemical or surgical modulation of the afferent pathway in two different species. This offers additional support for our hypothesis of transsynaptic regulation of intrinsic DA neurons of the bulb by the afferent olfactory chemoreceptor neurons.     

Antihemolytic and antioxidant activities of <Emphasis Type="Italic">Allium paradoxum</Emphasis>

Antioxidant activity of the aerial part and bulbs of Allium paradoxum was investigated by eight in vitro assay systems. Extracts showed good antioxidant activity. IC₅₀ for 1,1-diphenyl-2-picryl hydrazyl radical-scavenging activity was 890.9±43.2 and 984.9±33.5 μg/ml for the aerial part and bulbs, respectively. The aerial parts have better reducing power than bulb extracts but not comparable with Vitamin C (P>0.001). Extracts showed weak Fe²⁺ chelating ability, the IC₅₀ being 959±47 and 530±24 μg/ml for bulbs and aerial parts, respectively. Both tested extracts exhibited good hydrogen peroxide scavenging in a concentration dependent manner. They exhibited good antioxidant activity against the hemoglobin-induced linoleic acid system that was comparable with vitamin C (P>0.01). They showed good activity against cumene hydro peroxide induced hemolysis in RBCs. In addition, they possessed antihemolytic activity. The extract from aerial parts had significantly higher total phenol and flavonoid content than did bulbs. Amounts of eight elements (Cu, Mn, Zn, Fe, Ni, Pb, Cd and Cr) were also determined in the bulb and aerial part using atomic absorption spectroscopy. They contained higher Fe and Mn contents than other elements.     

Electrophysiological demonstration of independent olfactory receptor types and associated neuronal responses in the trout olfactory bulb

The present study attempts to highlight the principles by which peripheral olfactory information of across- and within-class odorant signals is transformed into bulbar neuron responses. For this purpose, we performed electro-olfactogram cross-adaptation and mixture experiments as well as single unit recording of olfactory bulb neurons using amino acid, bile acid and F-prostaglandin stimulants in brown and rainbow trout. The results show that amino acids, a bile acid and a F-prostaglandin activate independent receptor types. However, within the class of amino acids, different receptor types are only partially independent. Neurons responsive to bile acid and amino acids were segregated to the mid-dorsal and latero-posterior olfactory bulb, respectively. Of the 43 responsive olfactory bulb neurons studied in brown trout, 41 showed specificity for one odorant class. Olfactory bulb neurons gained responsiveness to new amino acids with increasing stimulant concentration. We conclude that different odorant classes activate specific neurons located in different regions of the trout olfactory bulb, and that information distinguishing related amino acids can be represented in a limited number of bulbar neurons with distinct response profiles under the conditions investigated.     

The role of metabolic activation of promutagens in the genome destabilization under pheromonal stress in the house mouse (<Emphasis Type="Italic">Mus musculus</Emphasis>)

The hypothesis on a relationship between the high frequency of mitotic disturbances in bone marrow cells and the change in the activity of the S9 liver fraction containing promutagen-activating enzymes under olfactory stress in the house mouse Mus musculus has been tested. For this purpose, the effect of the pheromone 2,5-dimethylpyrazine on the frequency of mitotic disturbances in mouse bone marrow cells has been measured by the anaphase-telophase assay. In paralled, we compared the capacities of the S9 liver fractions from stressed and intact mice for activating the promutagen 2-aminofluorene in the Ames test utilizing Salmonella typhimurium. It has been demonstrated that the increased frequency of mitotic disturbances in bone marrow cells induced by the pheromonal stressor in male house mice is accompanied by an increased ability of the S9 liver fraction to activate the promutagen. The model system used in the study allowed the genetic consequences of the exposure to the olfactory stressor to be estimated and the possible mechanisms of genome destabilization to be assumed.