Micronucleus frequency and lipid peroxidation in <Emphasis Type="Italic">Allium sativum</Emphasis> root tip cells treated with gibberellic acid and cadmium

Gibberellic acid (GA₃) is a very potent hormone whose natural occurrence in plants controls their development. Cadmium is a particularly dangerous pollutant due to its high toxicity and great solubility in water. In this study, the effect of GA₃ on Allium sativum root tip cells was investigated in the presence of cadmium. A. sativum root tip cells were exposed to CdNO₃ (50, 100, 200 μM), GA₃ (10-3 M), both CdNO₃ and GA₃. Cytogenetic analyses were performed as micronucleus (MN) assay and mitotic index (MI). Lipid peroxidation analysis was also performed in A. sativum root tip cells for determination of membrane damage. MN exhibited a dose-dependent increase in Cd treatments in A. sativum. GA₃ significantly reduced the effect of Cd on the MN frequency. MN was observed in GA₃ and GA₃ + 50 μm Cd treatments at very low frequency. MI slightly decreased in GA₃ and GA₃ + Cd treatments. MI decreased more in high concentrations of Cd than combined GA₃ + Cd treatments. The high concentrations of cadmium induce MN, lipid peroxidation and lead to genotoxicity in A. sativum. Current work reveals that the effect of Cd on genotoxicity can be partially restored with GA₃ application.     

沙葱(Allium mongolicum Regel)离体培养再生可育植株

以沙葱（Allium mongolicum Regel)的叶基切段作外植体,成功地诱导出愈伤组织和再生植株。诱导愈僵组织的培养基为附加2mgL^-22,4-D和0.2mgL^-1KT的MS培养基。愈伤组织转移到附加2mgL^-16BA和0.4mgL^-1NAA的MS培养基后分化出大量的苗;分化苗在含有IBA1mgL^-1的1/2MS培养基上生根最佳。再生植株移栽成活率在95%以上。移栽到田间的植株第二年以后可正常开花结实。     

Inhibitory effect of essential oils of Allium sativum and Piper longum on spontaneous muscular activity of liver fluke, Fasciola gigantica

Effects of essential oil of Allium sativum (garlic) and Piper longum (Indian long pepper) were evaluated on muscular activity of whole Fasciola gigantica and its strip preparation. The whole flukes and longitudinal strip preparations of the flukes were isometrically mounted to record the spontaneous muscular activity (SMA) and to evaluate effects of cumulative doses (0.1, 0.3, 1.0 and 3.0 mg/ml) of the plant essential oils. Whole flukes and the strip preparations exhibited continuous SMA without any significant difference in its baseline tension, frequency and amplitude for 2 h. Essential oil of A. sativum produced significant reduction in the frequency and the amplitude of the SMA of whole fluke at 1 and 3 mg/ml concentrations. It caused complete paralysis of the fluke after 15 min of administration of 3 mg/ml concentration. Similar to whole fluke, essential oil of A. sativum (3 mg/ml) also produced flaccid paralysis in the strip preparations of the flukes. Essential oil of P. longum firstly induced marked excitatory effect and then there was flaccid paralysis of the whole fluke following 15 min exposure at 3 mg/ml concentration. Complete flaccid paralysis of the strip preparation was also ensued after 15 min of administration of 3 mg/ml concentration of P. longum. In both the essential oils, the whole fluke and strip preparations did not recover from paralysis following 2-3 washes. In conclusion, the observations demonstrated irreversible paralytic effect of essential oils of A. sativum and P. longum on F. giganticain vitro which might possibly help to developing herbal-based anthelmintic.     

Cytotoxic and Genotoxic Effects of <Emphasis Type="Italic">cis</Emphasis>-Tetraammine(oxalato)Ruthenium(III) Dithionate on the Root Meristem Cells of <Emphasis Type="Italic">Allium cepa</Emphasis>

Ruthenium complexes have attracted much attention as possible building blocks for new transition-metal-based antitumor agents. The present study examines the mitotoxic and clastogenic effects induced in the root tips of Allium cepa by cis-tetraammine(oxalato)ruthenium(III) dithionate {cis-[Ru(C₂O₂)(NH₃)₄]₂(S₂O₆)} at different exposure durations and concentrations. Correlation tests were performed to determine the effects of the time of exposure and concentration of ruthenium complex on mitotic index (MI) and mitotic aberration index. A comparison of MI results of cis-[Ru(C₂O₂)(NH₃)₄]₂(S₂O₆) to those of lead nitrate reveals that the ruthenium complex demonstrates an average mitotic inhibition eightfold higher than lead, with the frequency of cellular abnormalities almost fourfold lower and mitotic aberration threefold lower. A. cepa root cells exposed to a range of ruthenium complex concentrations did not display significant clastogenic effects. Cis-tetraammine(oxalato)ruthenium(III) dithionate therefore exhibits a remarkable capacity to inhibit mitosis, perhaps by inhibiting DNA synthesis or blocking the cell cycle in the G2 phase. Further investigation of the mechanisms of action of this ruthenium complex will be important to define its clinical potential and to contribute to a novel and rational approach to developing a new metal-based drug with antitumor properties complementary to those exhibited by the drugs already in clinical use.     

葱卵细胞的分离

将大葱（Allium fistulosum）胚珠置于酶液中30分钟可将其外珠被去掉。可清楚地看到由内珠被包裹的胚珠中胚囊的轮廓。将胚珠转移至不含酶的相同溶液中,用解剖针从胚珠中部切割,然后挤压胚珠的珠孔部位,卵器细胞从胚珠的切口处逸出。再用显微操作仪将卵细胞和2个助细胞分开,达到葱卵细胞分离的目的。酶对分离卵细胞具有重要的作用,经0．2％果胶酶Y23、0．8％果胶酶、0．8％纤维素酶和0．5％半纤维素酶的处理,可在2小时内从30个胚珠中分离出18个卵细胞。随着胚囊的发育,2个助细胞的体积出现明显差异。生活的葱卵细胞的成功分离,为建立葱离体受精体系创造了条件。     

二甲戊灵对离体大蒜染色体的加倍研究

在MS分化培养基中分别添加不同浓度的秋水仙素和二甲戊灵,以 "改良蒜" 的蒜瓣基部为外植体诱导愈伤组织染色体变异并再生植株,观察根尖细胞染色体数和叶片下表皮保卫细胞特征检测诱变效果.结果表明:大蒜染色体数变异受诱变剂浓度和处理持续时间的影响,诱变剂高浓度和短时间处理均有利于大蒜愈伤组织的分化;添加0.1%秋水仙素处理5 d,愈伤组织存活率为80.7%,分化率为78.1%,四倍体的诱导率为4%;添加 100 μmol/L二甲戊灵处理5 d,愈伤组织存活率为100%,四倍体的诱导率为6%.对根尖细胞染色体和叶片下表皮气孔数目和大小观察显示,诱变株具有四倍体的基本特征.说明二甲戊灵能在离体条件下有效诱导大蒜产生四倍体,可替代秋水仙素对大蒜染色体的加倍作用.     

Genotoxicity assessment of a pharmaceutical effluent using four bioassays

Pharmaceutical industries are among the major contributors to industrial waste. Their effluents when wrongly handled and disposed of endanger both human and environmental health. In this study, we investigated the potential genotoxicity of a pharmaceutical effluent, by using the Allium cepa, mouse- sperm morphology, bone marrow chromosome aberration (CA) and micronucleus (MN) assays. Some of the physico-chemical properties of the effluent were also determined. The A. cepa and the animal assays were respectively carried out at concentrations of 0.5, 1, 2.5, 5 and 10%; and 1, 5, 10, 25 and 50% of the effluent. There was a statistically different (p < 0.05), concentration-dependent inhibition of onion root growth and mitotic index, and induction of chromosomal aberrations in the onion and mouse CA test. Assessment of sperm shape showed that the fraction of the sperm that was abnormal in shape was significantly (p < 0.05) greater than the negative control value. MN analysis showed a dose-dependent induction of micronucleated polychromatic erythrocytes across the treatment groups. These observations were provoked by the toxic and genotoxic constituents present in test samples. The tested pharmaceutical effluent is a potentially genotoxic agent and germ cell mutagen, and may induce adverse health effects in exposed individuals.     

Cytotoxic and genotoxic effects of Br-containing oxaphosphole on Allium cepa L. root tip cells and mouse bone marrow cells

The continuous production and release of chemicals into the environment has led to the need to assess their genotoxicity. Numerous organophosphorus compounds with different structures have been synthesized in recent years, and several oxaphosphole derivatives are known to possess biological activity. Such chemical compounds may influence proliferating cells and cause disturbances of the genetic material. In this study, we examined the cytotoxicity and genotoxicity of 4-bromo-N,N-diethyl-5,5-dimethyl-2,5-dihydro-1,2-oxaphosphol-2-amine 2-oxide (Br-oxph). In A. cepa cells, Br-oxph (10(-9) M, 10 (-6) M and 10 (-3) M) reduced the mitotic index 48 h after treatment with the two highest concentrations, with no significant effect at earlier intervals. Mitotic cells showed abnormalities 24 h and 48 h after treatment with the two lowest concentrations but there were no consistent changes in interphase cells. Bone marrow cells from mice treated with Br-oxph (2.82 x 10 (-3) μg/kg) also showed a reduced mitotic index after 48 h and a greater percentage of cells with aberrations (principally chromatid and isochromatid breaks). These findings indicate the cytotoxicity and genotoxicity of Br-oxph in the two systems studied.     

Comparative study of antioxidant capacity in organs of different Allium species

Cultivated and wild Allium species were investigated in order to compare the antioxidant capacity of their leaves and bulbs. Leaf and bulb anti-oxidative enzymes and scavenger activities, along with quantities of non-enzymic antioxidants, malonyl-dialdehyde and OH radicals were determined. Results obtained suggest that leaves possess higher anti-oxidant and scavenging activities than bulbs in the majority of cultivated and wild Allium species examined. Cultivation of some wild species such as A. flavum L., A. schoenoprasum L. and A. ursinum L. could be conducted in the future in order to produce Allium species with high antioxidant capacity in leaves and bulbs.     

大蒜体细胞胚胎发生过程中抗氧化酶活性变化及某些生理特征

以大蒜的发芽叶基(鳞茎)为外植体诱导体细胞胚胎发生,研究大蒜体胚发生过程中SOD、POD和CAT 3种抗氧化酶的活性以及可溶性糖和可溶性蛋白质含量变化.结果表明:在大蒜体胚发生过程中,SOD、POD和CAT活性变化与胚性愈伤组织的诱导及体胚的发育密切相关,POD对体胚的诱导起主导作用,而SOD和CAT在体胚的发育和成熟中起主导作用.可溶性糖和可溶性蛋白质累积与大蒜体细胞胚胎发生密切相关.