EFEITO DO EXTRATO AQUOSO DE DIFERENTES ESPÉCIES DE BOLDO SOBRE A GERMINAÇÃO E INDICE MITÓTICO DE ALLIUM CEPA L

Synthesis and Phytocytogenotoxic Activity of N-Phenyl-2-phenoxyacetamides Derived from Thymol

The excessive use of herbicides has caused a series of problems related to human health, environmental pollution, and an increase in the resistance of plants to commercial herbicides. As an alternative, natural compounds and their semisynthetic derivatives have been widely studied to obtain environmentally friendly and more effective herbicides than the usual ones. In view of these factors, the aim of this work was to synthesize new molecules with herbicidal potential using thymol as a starting material, a natural phenol that has a pronounced phytotoxic effect. Novel N-phenyl-2-thymoxyacetamides were synthesized and characterized by MS and by 1H and 13C NMR. All prepared molecules were subjected to phytotoxic and cytotoxic activity assays using Lactuca sativa L. and Sorghum bicolor L. as model plants. Molecules containing chlorine in the para position of the thymoxy group exhibited phytotoxic and cytogenotoxic effects superior to those of the commercial herbicides 2,4-D and glyphosate.

Are salty liquid food flavorings in vitro antitumor substances?

The objective of this study was to evaluate the antiproliferative, cytotoxic and genotoxic potential of salty liquid synthetic flavorings of Butter, Cheddar Cheese and Onion. The antiproliferative potential (2.9-1500 µg/mL) was assessed by MTT assay after 72h using the human tumor lines SF-295 (glioblastoma), OVCAR-8 (ovarian), HCT-116 (colon) and HL-60 (promyelocytic leukemia) and primary cultures of murine Sarcoma 180 (S180) and peripheral blood mononuclear cells (PBMC). Allium cepa bulbs were exposed to growing respective doses (1 mL and 2 mL). Only Butter and Cheddar flavorings revealed cytotoxic activity on cancer cells, with IC50 values ranging from 125.4 µg/mL (Cheddar - HCT-116) to 402.6 µg/mL (Butter - OVCAR-8). Butter flavoring was the most cytotoxic on PBMC (136.3 µg/mL) and increased cell division rate in relation to the mitotic index but did not cause cellular aberrations. Onion and Cheddar flavorings reduced the mitotic index after 24h and 48h exposure, but only Onion flavoring resulted in cellular aberrations and mitotic spindle abnormalities, such as anaphase and telophase bridges, micronucleated cells, conchicine-metaphases and amplifications. So, Butter, Onion and/or Cheddar flavorings caused significant changes in the division of meristematic cells of A. cepa and presented cytotoxic action even on decontrolled proliferating human tumor cells.

Cytotoxicity of Cheese and Cheddar Cheese food flavorings on Allim cepa L root meristems

Abstract Despite their great importance for the food industry, flavorings, in general, raise a number of questions regarding their cytotoxicity, mutagenicity and carcinogenicity, since, in the literature, there are few studies found evaluating the toxicity on the systemic and cellular level, of these chemical compounds. The root meristems of Allium cepa (onion) are widely used for the assessment of toxicity of chemical compounds of interest. Thus, this study aimed to evaluate, in A. cepa meristematic cells, individually and in combination at the cellular level, the toxicity of synthetic Cheese and Cheddar Cheese food flavorings, identical to the natural, at doses of 1.0 and 2.0 mL, at exposure times of 24 and 48 hours. In combination we used 0.5 mL of Cheese flavor associated with 0.5 mL of Cheddar flavor; and 1.0 mL of Cheese flavor associated with 1.0 mL of Cheddar flavor, at exposure times of 24 and 48 hours. For these evaluations, we used groups of five onion bulbs, which were first embedded in distilled water and then transferred to their respective doses. The root tips were collected and fixed in acetic acid (3:1) for 24 hours. The slides were prepared by crushing and were stained with 2% acetic orcein. Cells were analyzed throughout the cell cycle, totaling 5,000 for each control and exposure time. The mitotic indices calculated and cellular aberrations observed were subjected to statistical analysis using the chi-square test (p <0.05). No chromosomal abnormalities nor those of mitotic spindle were observed for the treatments performed. The results, both individually and in combination, showed that the flavorings under study significantly reduced the cell division rate of the test system cells used. Therefore, under the conditions studied, the two flavorings were cytotoxic.

Phytotoxicity and Cytotoxicity of Essential Oil from Leaves of Plectranthus amboinicus, Carvacrol, and Thymol in Plant Bioassays

The essential oil of Plectranthus amboinicus and its chemotypes, carvacrol and thymol, were evaluated on the germination and root and aerial growth of Lactuca sativa and Sorghum bicolor and in acting on the cell cycle of meristematic root cells of L. sativa. The main component found in the oil by analysis in gas chromatography-mass spectrometry and gas chromatography flame ionization detection was carvacrol (88.61% in area). At a concentration of 0.120% (w v(-1)), the oil and its chemotypes retarded or inhibited the germination and decreased root and aerial growth in monocot and dicot species used in the bioassays. In addition, all substances caused changes in the cell cycle of the meristematic cells of L. sativa, with chromosomal alterations occurring from the 0.015% (w v(-1)) concentration. The essential oil of P. amboinicus, carvacrol, and thymol have potential for use as bioherbicides.

Genetic damage induced by a food coloring dye (sunset yellow) on meristematic cells of Brassica campestris L

We have performed the present piece of work to evaluate the effect of synthetic food coloring azo dye (sunset yellow) on actively dividing root tip cells of Brassica campestris L. Three doses of azo dye were administered for the treatment of actively dividing root tip cells, namely, 1%, 3%, and 5%, for 6-hour duration along with control. Mitotic analysis clearly revealed the azo dye induced endpoint deviation like reduction in the frequency of normal divisions in a dose dependent manner. Mitotic divisions in the control sets were found to be perfectly normal while dose based reduction in MI was registered in the treated sets. Azo dye has induced several chromosomal aberrations (genotoxic effect) at various stages of cell cycle such as stickiness of chromosomes, micronuclei formation, precocious migration of chromosome, unorientation, forward movement of chromosome, laggards, and chromatin bridge. Among all, stickiness of chromosomes was present in the highest frequency followed by partial genome elimination as micronuclei. The present study suggests that extensive use of synthetic dye should be forbidden due to genotoxic and cytotoxic impacts on living cells. Thus, there is an urgent need to assess potential hazardous effects of these dyes on other test systems like human and nonhuman biota for better scrutiny.

Cytotoxicity of aqueous extracts of Rosmarinus officinalis L. (Labiatae) in plant test system

This study investigated the cytotoxic activity of Rosmarinus officinalis L. (rosemary) aqueous extract on the cell cycle of Allium cepa. To this end, crude aqueous leaf extracts at four concentrations, 0.02, 0.04, 0.06 and 0.08 mg/mL, were tested on A. cepa meristematic root cells, at exposure times of 24 and 48h. Slides were prepared by the crushing technique, and cells analyzed throughout the cell cycle, totaling 5,000 for each control group and concentration. The four concentrations tested, including the lowest and considered ideal for use, at all exposure times, showed a significant antiproliferative effect on the cell cycle of this test system and presented a high number of cells in prophase. Our results evidenced the cytotoxicity of rosemary extracts, under the studied conditions.

Action of Aqueous Extracts of Phyllanthus niruri L. (Euphorbiaceae) leaves on Meristematic Root Cells of Allium cepa L

This study aimed to evaluate the effects of aqueous extracts of dried Phyllanthus niruri L. (stonebreaker) leaves on Allium cepa L. root meristem cells at four concentrations, 0.02 (usual concentration), 0.04, 0.06 and 0.08mg/mL and exposure times of 24 and 48 hours. For each concentration we used a group of five onion bulbs that were first embedded in distilled water and then transferred to their respective concentrations. The radicles were collected and fixed in acetic acid (3:1) for 24 hours. The slides were prepared by the crushing technique and stained with 2% acetic orcein. Cells were analyzed throughout the cell cycle, totaling 5000 for each control and exposure time. The calculated mitotic indices were subjected to the Chi-squared statistical analysis (p<0.05). From the results obtained it was observed that all four concentrations tested had significant antiproliferative effect on the cell cycle of this test system. We also found the presence of cellular aberrations such as colchicined metaphases, anaphasic and telophasic bridges, and micronuclei in the two exposure times for all concentrations evaluated. Therefore, under the conditions studied the concentrations of aqueous extracts of leaves of P. niruri showed to be cytotoxic and genotoxic.

Citotoxicity of food dyes sunset yellow (E-110), bordeaux red (E-123), and tatrazine yellow (E-102) on Allium cepa L. root meristematic cells

The objective of this study was to evaluate the cytotoxic effect of the food dyes sunset yellow, bordeaux red, and tartrazine yellow on the cellular cycle of Allium cepa L. Each dye was evaluated at the doses of 0.4 and 4.0 mL, at the exposure times of 24 and 48 hours in root tip cells of Allium cepa L. Slides were prepared and cells were analyzed during the whole cell cycle for cellular aberrations totaling 5,000 total cells for each dose evaluated. The mitotic index was calculated, and statistical analysis was performed using the Chi-squared test (p < 0.05). The results showed that the three dyes used under the evaluated doses and exposure times were cytotoxic to the cells of the system-test used. Further cytotoxicity studies should be conducted for additional results and a proper evaluation of the effect of these three dyes on a cellular level.