Investigation of the cytocidal potential of Rhinella jimi skin methanol extracts

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

In Vitro Evaluation of the Genotoxic Activity and Apoptosis Induction of the Extracts of Roots and Leaves from the Medicinal Plant Coccoloba mollis (Polygonaceae)

Coccoloba mollis (Family Polygonaceae) is a medicinal plant popularly used in cases of memory loss, stress, insomnia, anemia, impaired vision, and sexual impotence, but the scientific literature, to date, lacks studies on the biological effects of this species, particularly with regard to cytotoxicity and induction of DNA damage. The aim of the present study was to assess in vitro (in hepatic HTC cells) ethanolic extracts of the roots and leaves of C. mollis for cytotoxicity, genotoxicity, and induction of apoptosis. For these evaluations the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay, comet assay, micronucleus test with cytokinesis block, and an in situ test for detection of apoptotic cells with acridine orange staining were used. The results showed that the extract obtained from the roots of C. mollis is more cytotoxic than that obtained from the leaves and that the reduction in cell viability observed in the MTT assay was a result, at least in part, from the induction of apoptosis. Both extracts induced DNA damage at a concentration of 20 mu g/mL in the comet assay, but no genotoxicity was detected with any of the treatments carried out in the micronucleus test.

Toxicologic evaluation of acute and subacute oral administration of Cucurbita maxima seed extracts to rats and swine

The extract prepared from dried seeds of Cucurbita maxima was administered to rats and pigs. Following a single dose or 4 weeks of daily oral administration, the extract produced no changes in serum glucose, urea, creatinine, total protein, uric acid, GOT, GPT, LDH or blood counts. Urine analysis (urea, uric acid, creatinine, total protein, Na and K), as well as histopathological investigation, showed no abnormalities. These results taken as a whole indicate that the seeds of C. maxima as used in Brazilian folk medicine are not toxic for rats and swine.

Anti-genotoxic effect of aqueous extracts of sun mushroom (Agaricus blazei Murill lineage 99/26) in mammalian cells in vitro

The sun mushroom is the popular name for the Agaricus blazei Murill fungus, a mushroom native to south-eastern Brazil, which has been frequently used in popular medicine mainly in the form of tea to treat various ailments (stress, diabetes, etc.). In the present study, the genotoxic and/or anti-genotoxic effects ofA. blazei on mammalian cells in culture was assessed by checking the increase or reduction of micronucleus (MN) frequency and comets. The sun mushroom (lineage 99/26) was used as aqueous extracts prepared (2.5%) at three different temperatures (60, 25 and 4°C). The in vitro micronucleus (MN) test in binucleated cells and comet assay were used in V79 cells cultivated in HAM-F10+DMEM medium (1:1), supplemented with 10% of fetal bovine serum. The experiments were divided into four treatment types: 1. Negative control; 2. Positive control with MMS; 3. Treatments with the three forms of extracts (60, 25 and 4°C); and 4. Treatments with the extracts in different associations (simultaneous, pre-treatment, post-treatment and simultaneous after pre-incubation for 1 h) with MMS. None of the A. blazei extracts show genotoxic activity. In the comet assay no protecting effect was found. The results obtained in the MN test showed that the three forms of extracts used had protective activity, suggesting that the compound or active ingredients of A. blazei are always present in these extracts. The greater protective efficiency of the simultaneous treatment and simultaneous treatment with pre-incubation mixture with MMS suggests that the extracts have an antimutagenic action of the desmutagenic type. © 2002 Elsevier Science Ltd. All rights reserved.

Effects of crude extracts of Agaricus blazei on DNA damage and on rat liver carcinogenesis induced by diethylnitrosamine

The effects of crude extracts of the mushroom Agaricus blazei Murrill (Agaricaceae) on both DNA damage and placental form glutathione S-transferase (GST-P)-positive liver foci induced by diethylnitrosamine (DEN) were investigated. Six groups of adult male Wistar rats were used. For two weeks, animals of groups 3 to 6 were treated with three aqueous solutions of A. blazei (mean dry weight of solids being 1.2, 5.6, 11.5 and 11.5 mg/ml, respectively). After this period, groups 2 to 5 were given a single ip injection 200 mg/kg DEN and groups 1 and 6 were treated with 0.9% NaCl. All animals were subjected to 70% partial hepatectomy at week five and sacrificed 4, 24 and 48 h or 8 weeks after DEN or 0.9% NaCl treatments (10th week after the beginning of the experiment). The alkaline comet assay and GST-P-positive liver foci development were used to evaluate the influence of the mushroom extracts on liver cell DNA damage and on the initiation of liver carcinogenesis, respectively. Previous treatment with the highest concentration of A. blazei (11.5 mg/ml) significantly reduced DNA damage, indicating a protective effect against DEN-induced liver cytotoxicity/genotoxicity. However, the same dose of mushroom extract significantly increased the number of GST-P-positive liver foci.

Genotoxic and antigenotoxic effects of organic extracts of mushroom Agaricus blazei Murrill on V79 cells

Agaricus blazei Murrill, popularly known as the sun mushroom, is a native mushroom in SP, Brazil, that has been widely used in the treatment of cancer and many other pathologies in different parts of the world. A water-soluble protein-polysaccharide complex (1 → 6)β-D-glucan has been isolated from its fruiting body that showed immune-modulation activity. From organic extracts, linoleic acid has been isolated and determined to be the main substance with antimutagenic activity. Using both the micronucleus (MN) and comet (single cell microgel electrophoresis) assays, this study determined the genotoxic and antigenotoxic potential of A. blazei (AB) obtained from commercial sources or the following strains: a) strains AB 97/29 (young and sporulated phases); b) a mixture taken from AB 96/07, AB 96/09 and AB 97/ 11 strains; and c) commercial mushrooms from Londrina, PR and Piedade, SP, designated as AB PR and AB SP, respectively. The extracts from these mushrooms were isolated in chloroform:methanol (3:1) and used in vitro at three different concentrations. V79 cells (Chinese hamster lung cells) were exposed to the extracts under pre-, simultaneous and post-treatment conditions, combined with methyl methanesulfonate (MMS). Under the circumstances of this study, these organic extracts did not show any genotoxic or mutagenic effects, but did protect cells against the induction of micronuclei by MMS. Copyright by the Brazilian Society of Genetics.

Assessment of DNA damage by extracts and fractions of Strychnos pseudoquina, a Brazilian medicinal plant with antiulcerogenic activity

Strychnos pseudoquina St. Hil. is a native plant of the Brazilian Savannah, used in popular medicine to treat a number of conditions. Since it contains large quantities of alkaloids with proven antiulcer activity, we tested the genotoxic potential of crude extracts and fractions containing alkaloids and flavonoids from the leaves of this plant, on Salmonella typhimurium and performed the micronucleus test on peripheral blood cells of mice treated in vivo. The results showed that the methanol extract of the leaves of S. pseudoquina is mutagenic to the TA98 (-S9) and TA100 (+S9, -S9) strains of Salmonella. The dichloromethane extract was not mutagenic to any of the tested strains. Fractions enriched with alkaloids or flavonoids were not mutagenic. In vivo tests were done on the crude methanol extract in albino Swiss mice, which were treated, by gavage, with three different doses of the extract. The highest dose tested (1800 mg/kg b.w.) induced micronuclei after acute treatment, confirming the mutagenic potential of the methanol extract of the leaves of S. pseudoquina. In high doses, constituents of S. pseudoquina compounds act on DNA, causing breaks and giving rise to micronuclei in the blood cells of treated animals. © 2006 Elsevier Ltd. All rights reserved.

Cytotoxic effects of hard-setting cements applied on the odontoblast cell line MDPC-23

Objective: The present study evaluated the cytotoxic effects of hard setting applied on the odontoblastlike cells MDPC-23. Study design: Eighty round-shaped samples were prepared with the following experimental materials: calcium hydroxide, Vitrebond, RelyX Luting, and RelyX Unicem. The samples were placed in serum-free culture medium and incubated for 24 hours or 7 days at 37°C with 5% CO 2 and 95% air. The odontoblast cells were plated in the wells and incubated for 72 hours. After this period, the complete culture medium was replaced by the extracts obtained from every sample, and the methyltetrazolium assay was carried out to evaluate the cell metabolism. Results: For the 24-hour period, the experimental materials calcium hydroxide, Vitrebond, RelyX Luting, and RelyX Unicem decreased the cell metabolic activity by 91.52%, 81.14%, 78.17%, and 2.64%, respectively. For the 7-day period, calcium hydroxide, Vitrebond, RelyX Luting, and RelyX Unicem decreased the metabolic activity of the MDPC-23 cells by 91.13%, 87.27%, 79.04%, and 10.51%, respectively. Conclusion: RelyX Unicem presented the lowest cytopathic effects to the cultured odontoblast cell line. © 2007 Mosby, Inc. All rights reserved.

Identification of ellagic acid derivatives in methanolic extracts from Qualea species

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cytotoxicity of Brazilian plant extracts against oral microorganisms of interest to dentistry

Background: With the emergence of strains resistant to conventional antibiotics, it is important to carry studies using alternative methods to control these microorganisms causing important infections, such as the use of products of plant origin that has demonstrated effective antimicrobial activity besides biocompatibility. Therefore, this study aimed to evaluate the antimicrobial activity of plant extracts of Equisetum arvense L., Glycyrrhiza glabra L., Punica granatum L. and Stryphnodendron barbatimam Mart. against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Candida albicans, Candida tropicalis, and Candida glabrata, and to analyze the cytotoxicity of these extracts in cultured murine macrophages (RAW 264.7).Methods: Antimicrobial activity of plant extracts was evaluated by microdilution method based on Clinical and Laboratory Standards Institute (CLSI), M7-A6 and M27-A2 standards. The cytotoxicity of concentrations that eliminated the microorganisms was evaluated by MTT colorimetric method and by quantification of proinflammatory cytokines (IL-1β and TNF-α) using ELISA.Results: In determining the minimum microbicidal concentration, E. arvense L., P. granatum L., and S. barbatimam Mart. extracts at a concentration of 50 mg/mL and G. glabra L. extract at a concentration of 100 mg/mL, were effective against all microorganisms tested. Regarding cell viability, values were 48% for E. arvense L., 76% for P. granatum L, 86% for S. barbatimam Mart. and 79% for G. glabra L. at the same concentrations. About cytokine production after stimulation with the most effective concentrations of the extracts, there was a significant increase of IL-1β in macrophage cultures treated with S. barbatimam Mart. (3.98 pg/mL) and P. granatum L. (7.72 pg/mL) compared to control (2.20 pg/mL) and a significant decrease of TNF-α was observed in cultures treated with G. glabra L. (4.92 pg/mL), S. barbatimam Mart. (0.85 pg/mL), E. arvense L. (0.83 pg/mL), and P. granatum L. (0.00 pg/mL) when compared to control (41.96 pg/mL).Conclusions: All plant extracts were effective against the microorganisms tested. The G. glabra L. extract exhibited least cytotoxicity and the E. arvense L. extract was the most cytotoxic. © 2013 de Oliveira et al.; licensee BioMed Central Ltd.

Morphological Alterations in the Synganglion and Integument of Rhipicephalus sanguineus Ticks Exposed to Aqueous Extracts of Neem Leaves (Azadirachta indica A. JUSS)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Inorganic elemental analysis and identification of residual monomers released from different glass ionomer cements in cell culture medium

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Antifungal activity of extracts and isolated compounds from Buchenavia tomentosa on Candida albicans and non-albicans

Aim: This study aimed to evaluate the antifungal activity of Buchenavia tomentosa extract and bioactive compounds on six Candida species. Materials & methods: The antimicrobial activity of extract was evaluated using standard strains and clinical isolates. Cytotoxicity was tested in order to evaluate cell damage caused by the extract. Extract was chemically characterized and the antifungal activity of its compounds was evaluated. Results: Extract showed antifungal activity on Candida species. Candida non-albicans were more susceptible than Candida albicans. Low cytotoxicity for extract was observed. The isolated compounds presented antifungal activity at least against one Candida spp. and all compounds presented antifungal effect on Candida glabrata. Conclusion: Extracts from Buchenavia tomentosa showed promising antifungal activity on Candida species with low cytotoxicity. Gallic acid, corilagin and ellagic acid showed promising inhibitory activity on Candida glabrata.

Development of a synbiotic low-calorie beverage made from soy and yacon extracts

The objective of this study was to develop a new low-calorie symbiotic beverage made from yacon (prebiotic source) and soy extracts, containing probiotic Bifidobacterium animalis ssp. lactis BB-12. The synbiotic beverage was first produced with a range of sucrose concentrations in order to determine ideal sweetness by an acceptance test using a “just-about-right scale”. Sucrose was then replaced by sucralose or aspartame to produce sugar-free beverages. Characteristics including viable cell numbers, physicochemical properties, sensorial characteristics and fructooligosaccharides content were investigated. The ideal sweetness of the beverages with sucrose, aspartame and sucralose were 7.28%, 0.0486% and 0.0167%, respectively. Sucralose exhibited higher scores in acceptance test and was used to replace sucrose in the low-calorie symbiotic beverage. The synbiotic beverage exhibited counts of Bifidobacterium spp. of 108 CFU·mL-1 , sufficient condition to be considered probiotic. The chemical composition of the product was (g/100 g): 2.91 of protein, 1.41 of fat, 2.41 of total carbohydrate; 0.82 of FOS and 148.22 Kj of energy value. The synbiotic beverage developed in this study may be successful in health applications, due to their functional ingredients (soy, probiotic bacteria and yacon prebiotics) that can afford benefits to health or can present disease-preventing properties, beyond their inherent nutritional value. In addition this low-calorie beverage can be consumed by diabetic individuals and people concerned about the ingestion of calories.