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Styrax camporum Pohl, a typical species from the Brazilian cerrado, commonly known as "benjoeiro", is used to treat gastroduodenal diseases. In previous studies carried out by our research group, hydroalcoholic extract of S. camporum stems (SCHE) exhibited antigenotoxic and antiproliferative effects. For a comparative analysis of the chemopreventive effect of SCHE, the aim of this study was to investigate the influence of SCHE against carcinogen 1,2-dimethylhydrazine (DMH)-induced DNA damage and pre-neoplastic lesions in Wistar rat colon. Animals were treated orally with SCHE at 250, 500 or 1000 mg/kg body weight in conjunction with a subcutaneous injection of DMH. DNA damage was assessed using the comet assay while tpre-neoplastic lesions by aberrant crypt foci (ACF) assay. The following hepatic oxidative stress markers were determined including activities of catalase (CAT) and glutathione S-transferase (GST) as well as levels of reduced glutathione (GSH) and malondialdehyde (MDA). Treatment with SCHE was not genotoxic or carcinogenic at the highest dose tested (1000 mg/kg b.w.). The extract effectively inhibited DNA damage and pre-neoplastic lesions induced by DMH administration at all concentrations tested. Measurement of CAT, and GST activities and levels of GSH showed that SCHE did not reduce oxidative processes. In contrast, treatment with SCHE (1000 mg/kg b.w.) decreased liver MDA levels. Taken together, these findings suggested the chemopreventive effect attributed to SCHE in colon carcinogenesis, may be related to its capacity to inhibit DNA damage as well as an antioxidant action associated with its chemical constituents egonol and homoegonol.

Ethnopharmacological relevance Copaifera species are used in folk medicine for a wide variety of pharmacological properties. This paper reports the cytotoxic and genotoxic analyses of oleoresins and leaves extracts of Copaifera species: C. duckei, C. multijuga, C. paupera, C. pubiflora, C. reticulata and C. trapezifolia. Materials and methods In vitro assays were performed using Chinese hamster lung fibroblasts (V79 cells). The clonogenic efficiency and cytokinesis-block micronucleus assays were employed for the cytotoxicity and genotoxicity assessment, respectively. The mouse bone marrow micronucleus test was used for in vivo studies. Results The cytotoxicity results using the clonogenic efficiency assay showed IC50 values ranging from 9.8 to 99.2 µg/mL for oleoresins and 66.4–721.5 for leaves extracts. However, no cytotoxic effect was observed in the in vivo studies. Additionally, the treatments with oleoresins and leaves extracts did not significantly increase the frequency of micronuclei in both in vitro and in vivo mammalian cells. The UPLC-MS/MS and CG/MS analyses of Copaifera oleoresins allowed the identification of 10 acid diterpenes and 11 major volatile sesquiterpenes. Leaves are rich in phenolic compounds including two flavonoid heterosides and 16 galloylquinic acid derivatives. Conclusions The oleoresins and leaves extracts of studied Copaifera species were not cytotoxic in vivo, as well as not genotoxic in both in vitro and vivo assays, under the experimental conditions used. Therefore, the obtained results should be sufficient to demonstrate the absence of significant genotoxic risk of these Copaifera products for human use in the evaluated concentrations range.

Copaiba oleoresins are used in alternative medicine as anti-inflammatory, antitumoral, and antimicrobial treatments. (-)-Copalic acid (CA) is the major diterpene found in exudates from Copaifera species. We have examined the genotoxicity and the chemopreventive potential of Copaifera multijuga oleoresin (CM) and CA. Genotoxicity assessment was examined with the peripheral blood micronucleus test and the comet assay (male Swiss mouse hepatocytes). In the chemoprevention study, we evaluated the effects of CM and CA on the formation of 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) in male Wistar rat colon. Neither agent caused a significant increase in micronucleus frequency relative to controls, but the highest CM dose tested (400mg/kg b.w.) caused DNA damage in the comet assay. Both agents significantly reduced the frequency of DMH-induced ACF. Both CM and CA suppressed ACF formation and may have a protective effect against colon carcinogenesis.

The microorganisms that constitute the oral microbiome can cause oral diseases, including dental caries and endodontic infections. The use of natural products could help to overcome bacterial resistance to the antimicrobials that are currently employed in clinical therapy. This study assessed the antimicrobial activity of the Copaifera pubiflora oleoresin and of the compounds isolated from this resin against oral bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays provided values ranging from 6.25 to > 400 μg/mL for the C. pubiflora oleoresin and its isolated compounds. The fractional inhibitory concentration index (FICI) assay showed that the oleoresin and chlorhexidine did not act synergistically. All the tested bacterial strains formed biofilms. MICB50 determination revealed inhibitory action: values varied from 3.12–25 μg/mL for the oleoresin, and from 0.78 to 25 μg/mL for the ent-hardwickiic acid. Concerning biofilm eradication, the C. pubiflora oleoresin and hardwickiic acid eradicated 99.9 % of some bacterial biofilms. Acid resistance determination showed that S. mutans was resistant to acid in the presence of the oleoresin and ent-hardwickiic acid at pH 4.0, 4.5, and 5.0 at all the tested concentrations. Analysis of DNA/RNA and protein release by the cell membrane demonstrated that the oleoresin and hardwiickic acid damaged the bacterial membrane irreversibly, which affected membrane integrity. Therefore, the C. pubiflora oleoresin and ent-hardwickiic acid have potential antibacterial effect and can be used as new therapeutic alternatives to treat oral diseases such as dental caries and endodontic infections.

The species Inga laurina is native to the Brazilian Cerrado. There are no studies about the chemical composition and biological activities of extracts of this endangered species. The ethanolic extract and its successive fractions are rich in phenolic compounds and presented good antifungal activities. HPLC/MS-MS/MS and H1/C13 analysis led to the identification of seventeen compounds, most of which are gallic acid derivatives, myricetin and quercetin glycosides. The ethyl acetate fraction (EAF) contained high levels of total phenolics, expressed in milligrams of gallic acid equivalents per gram of extract (475.3 ± 1.9 mg GAE gextract-1) and flavonoids expressed in milligrams of quercetin equivalents per gram of extract (359.3 ± 10.6 mg QE gextract-1). This fraction was active against fungi of the Candida genus. The EAF showed MIC value 11.7 μg mL−1 against C. glabrata and a selectivity index of 1.6 against Vero cells. The flavonol glycoside myricetin-3-O-rhamnoside was isolated for the first time from the Inga laurina. These results make I. laurina a promising plant as a source of pharmaceutical and biological active antifungal compounds.

The use of poorly treated water in hemodialysis centers may lead to fungal contamination, which poses a serious threat to immunologically debilitated hemodialysis patients. This study aimed to isolate and identify yeast species in the water of a Brazilian hemodialysis center by using classic microbiological techniques and Raman spectroscopy. For 12 months, a total of 288 water samples were collected from different points of the hemodialysis treatment distribution center. One hundred and forty-six yeast species were isolated and identified in the samples that tested positive for the presence of yeasts such as Candida parapsilosis (100 isolates, or 68.50%), C. guilliermondii (17 isolates, or 11.65%), Rhodotorula mucilaginosa (23 isolates, or 15.75%), R. glutinis (three isolates, or 2.05%), and Trichosporon inkin (three isolates, or 2.05%). Yeast susceptibility to the antifungal fluconazole was also assayed. Only two C. guilliermondii isolates were resistant to fluconazole: the minimal inhibitory concentrations were higher than 64 μg/mL. The different yeast species present in the water of a Brazilian hemodialysis center call for more effective water disinfection procedures in this unit. Raman spectroscopy is an excellent tool to identify yeast species and is potentially applicable in routine water monitoring in hemodialysis units.

Diterpenes are an important class of plant metabolites that can be used in the search for new antibacterial agents. ent-Copalic acid (CA), the major diterpene in Copaifera species exudates, displays several pharmacological properties. This study evaluates the CA antibacterial potential against the anaerobic bacteria Peptostreptococcus anaerobius and Actinomyces naeslundii. Antimicrobial assays included time-kill and biofilm inhibition and eradication assays. Time-kill assays conducted for CA concentrations between 6.25 and 12.5 μg/mL evidenced bactericidal activity within 72 h. CA combined with chlorhexidine dihydrochloride (CHD) exhibited bactericidal action against P. anaerobius within 6 h of incubation. As for A. naeslundii, the same combination reduced the number of microorganisms by over 3 log10 at 24 h and exerted a bactericidal effect at 48 h of incubation. CA at 500 and 2000 μg/mL inhibited P. anaerobius and A. naeslundii biofilm formation by at least 50%, respectively. CA at 62.5 and 1.000 μg/mL eradicated 99.9% of pre-formed P. anaerobius and A. naeslundii biofilms, respectively. These results indicated that CA presents in vitro antibacterial activity and is a potential biofilm inhibitory agent. This diterpene may play an important role in the search for novel sources of agents that can act against anaerobic bacteria.

In this work, we used the Minimum Inhibitory Concentration (MIC) technique to evaluate the antibacterial potential of the apitoxin produced by Apis mellifera bees against the causative agents of tooth decay. Apitoxin was assayed in naturaand in the commercially available form. The antibacterial actions of the main components of this apitoxin, phospholipase A2, and melittin were also assessed, alone and in combination. The following bacteria were tested: Streptococcus salivarius, S. sobrinus, S. mutans, S. mitis, S. sanguinis, Lactobacillus casei, and Enterococcus faecalis. The MIC results obtained for the commercially available apitoxin and for the apitoxin in natura were close and lay between 20 and 40µg / mL, which indicated good antibacterial activity. Melittin was the most active component in apitoxin; it displayed very promising MIC values, from 4 to 40µg / mL. Phospholipase A2 presented MIC values higher than 400µg / mL. Association of mellitin with phospholipase A2 yielded MIC values ranging between 6 and 80µg / mL. Considering that tooth decay affects people's health, apitoxin and its component melittin have potential application against oral pathogens. O presente estudo avaliou pela técnica da Concentração Inibitória Mínima (CIM) o potencial antibacteriano da apitoxina produzido pela abellha Apis melifera frente aos microrganismos causadores da cárie dental. Apitoxina foi avaliada na forma in naturae comercial. A ação antibacteriana dos principais componentes da apitoxina, fosfolipase A2 e melitina foram também avaliados, isolados e em combinação. As bactérias testadas foram: Streptococcus salivarius, S. sobrinus, S. mutans, S. mitis, S. sanguinis, Lactobacillus caseie Enterococcus faecalis. Os resultados da CIM da apitoxina comercial e in natura foram muito próximos, variando entre 20 µg/mL e 40µg/mL, ambas apresentaram uma boa atividade antibacteriana. Entre os componentes, a melitina foi a mais ativa, exibindo valores de CIM muito promissores, variando de 4 a 40μg/mL. A fosfolipase A2 apresentou resultados maiores que 400 µg/mL. A associação entre a melitina e fosfolipase A2apresentou resultados da CIM que variaram entre 6µg/mL e 80µg/mL. Considerando que a cárie dental afeta a saúde das pessoas, a apitoxina e seu composto, melitina, possuem potencial aplicação frente aos patógenos bucais.

Made available in DSpace on 2018-11-26T17:48:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) In view of the biological activities and growing therapeutic interest in oleoresin obtained from Copaifera multijuga, this study aimed to determine the genotoxic and antigenotoxic potential of this oleoresin (CMO) and its chemical marker, diterpene (-)-copalic acid (CA). The micronucleus (MN) assay in V79 cell cultures and the Ames test were used for in vitro analyses, as well as MN and comet assays in Swiss mice for in vivo analyses. The in vitro genotoxicity/mutagenicity results showed that either CMO (30, 60, or 120 mu g/ml-MN assay; 0.39-3.12 mg/plate-Ames test) or CA (2.42; 4.84, or 9.7 mu g/ml-MN assay; 0.39-3.12 mg/plate-Ames test) did not induce a significant effect on the frequency of MN and number of revertants, demonstrating an absence of genotoxic and mutagenic activities, respectively, in vitro. In contrast, these natural products significantly reduced the frequency of MN induced by methyl methanesulfonate (MMS), and exerted a marked inhibitory effect against indirect-acting mutagens in the Ames test. In the in vivo test system, animals treated with CMO (6.25 mg/kg b.w.) exhibited a significant decrease in rate of MN occurrence compared to those treated only with MMS. An antigenotoxic effect of CA was noted in the MN test (1 and 2 mg/kg b.w.) and the comet assay (0.5 mg/kg b.w.). Data suggest that the chemical marker of the genus Copaifera, CA, may partially be responsible for the observed chemopreventive effect attributed to CMO exposure. Univ Franca, Dept Ciencias, BR-14404600 Franca, SP, Brazil Univ Araraquara, Grp Pesquisa Quim Med & Med Regenerat, Araraquara, SP, Brazil Univ Estadual Paulista, Fac Ciencias Farmaceut Araraquara, Dept Ciencias Biol, Araraquara, SP, Brazil Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Dept Ciencias Farmaceut, Ribeirao Preto, SP, Brazil Univ Estadual Paulista, Fac Ciencias Farmaceut Araraquara, Dept Ciencias Biol, Araraquara, SP, Brazil FAPESP: 2011/13630-7 FAPESP: 2009/17237-8

Antibiotic-resistant bacteria have emerged from the widespread use of antibiotics worldwide and have prompted the search for new sources of antimicrobial substances. Pinus spp. contain several bioactive compounds consisting mainly of terpenes, terpenoids and some other aromatic and aliphatic constituents. These compounds exert important biological effects, and pine oils have found wide application in the industry. In the present study, we have evaluated the potential activity of the resin-oil of Pinus elliottii and its major compound dehydroabietic acid (DA) against multiresistant bacteria by MIC, minimum bactericidal concentration and time-kill assays. The MIC of the resin-oil of P. elliottii varied between 25 and 100 µg ml−1. As for DA, the MIC and minimum bactericidal concentration varied between 6.25 and 50 and between 6.25 and 100 µg ml−1, respectively. The time-kill assay conducted with DA at 6.25 µg ml−1 evidenced bactericidal activity against Staphylococcus epidermidis (American Type Culture Collection 14990) within 24 h. On the basis of these results, the resin-oil of P. elliottii and its major compound DA play an important part in the search for novel sources of agents that can act against multiresistant bacteria.

The seasonal chemical composition of essential oils from Inga laurina was determined by GC/MS. In the stem bark’s essential oil extracted during the dry season, the presence of terpenoids (30.05%) stood out, and phytol (9.76%) was the major compound identified. For the stem bark oil obtained during the rainy season, in addition to terpenoids (26.63%), a large amount of fatty acids (46.84%) were identified, in particular palmitic acid (25.40%). Regarding the leaves’ essential oil obtained in the dry season, esters (42.35%) were the main components. The main ester present was (Z)-hex-3-enyl benzoate (10.15%) and the major compound of this oil was (Z)-hex-3-en-1-ol (14.23%). Terpenoids (33.84%), long-chain alkanes (27.04%) and fatty acids (21.72%) were the main components of the essential oil from leaves in the rainy season. Phytol (33.21%), nonacosane (21.95%) and palmitic acid (15.20%) were the major compounds identified. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated by the microdilution broth method and cytotoxic activity was carried out with Vero cells. The essential oils from the rainy season showed a better inhibition of the bacterial growth with Minimal Inhibitory Concentrations (MIC) values of 25 or 50 µg·mL−1 for aerobic bacteria, and high selectivity against bacteria was observed. The large amount of fatty acids in rainy season oils may be related to the better inhibitory effects observed.

Usnic acid is one of the most common and abundant metabolites found in various lichen genera, which are important sources of biologically active compounds. The aim of this study was to evaluate the genotoxic and antigenotoxic potential of (+)-usnic acid (UA) by the micronucleus and comet assays in V79 cell cultures and Swiss mice. For assessment of genotoxicity, V79 cells were treated with 15, 30, 60, and 120μg/mL UA, established based on clonogenic efficiency cytotoxic assay. Swiss mice were treated with UA doses of 25, 50, 100, and 200mg/kg body weight. The same concentrations of UA were combined with methyl methanesulfonate (MMS) for evaluation of antigenotoxicity. The in vitro results demonstrated that UA induced DNA damage at concentrations of 60 and 120μg/mL in the comet assay. However, no genotoxic effect was observed in the micronucleus test using V79 cells at the concentrations tested. No genotoxic effects were observed for the different UA treatments in in vivo test system. Combined administration of UA and MMS significantly reduced the frequencies of micronuclei and DNA damage in vitro and in vivo when compared to treatment with MMS alone. Although the mechanisms underlying the protective effect of UA are not completely understood, the antioxidant activity of this metabolite may explain its protective effect against MMS-induced genotoxicity.

The use of poorly treated water during hemodialysis may lead to contamination with nontuberculous mycobacteria (NTM). This study aimed to isolate and identify NTM species in the water of a Brazilian hemodialysis center. We collected 210 samples of water from the hydric system of the unit (post-osmosis system, hemodialysis rooms, reuse system, and hemodialysis equipment) and from the municipal supply network; we isolated the NTM by a classic microbiological technique and identified them by the PCR restriction enzyme pattern of the hsp65 gene (PRA). Fifty-one (24.3 %) of the collected samples tested positive for NTM; both the municipal supply network (2 samples, 3.2 %) and the hydric system of the hemodialysis center (49 samples, 96.1 %) contained NTM. We isolated and identified potentially pathogenic bacteria such as Mycobacterium lentiflavum (59.0 %) and M. kansasii (5.0 %), as well as rarely pathogenic bacteria like M. gordonae (24.0 %), M. gastri (8.0 %), and M. szulgai (4.0 %). The ability of NTM to cause diseases is well documented in the literature. Therefore, the identification of NTM in the water of a Brazilian hemodialysis center calls for more effective water disinfection procedures in this unit.

The aim of this study was to examine the cytotoxic and genotoxic potential of a hydroethanolic extract of Schefflera vinosa (SV), a plant with schistosomicidal activity, as well as its influence on DNA damage induced by different mutagens, methyl methane sulfonate (MMS) and hydrogen peroxide (H2O2), in V79 cells and Swiss mice. Schefflera vinosa extract produced cytotoxicity at concentrations of 312.5 µg/ml or higher using the XTT cell proliferation assay kit. Treatment of V79 cell cultures with the highest SV concentration tested (150 µg/ml) significantly increased the frequency of micronuclei (MN) compared to controls. All SV concentrations significantly reduced the frequency of MN induced by hydrogen peroxide in V79 cell cultures. Further, SV was able to scavenge free radicals in the DPPH assay. In the in vivo test system, treatment with the highest dose tested (1,000 mg/kg body weight) induced a significant rise in frequency of DNA damage using the comet assay. However, animals treated with di...

Made available in DSpace on 2018-11-27T21:47:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-09-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Copaifera trapezifolia Hayne occurs in the Atlantic Rainforest, which is considered one of the most important and endangered tropical forests on the planet. Although literature works have described many Copaifera spp., their biological activities remain little known. In the present study, we aimed to evaluate (1) the potential of the hydroalcoholic extract from C. trapezifolia leaves (CTE) to act against the causative agents of tooth decay and apical periodontitis and (2) the cytotoxicity and mutagenicity of CTE to ensure that it is safe for subsequent application. Concerning the tested bacteria, the MIC and the minimum bactericidal concentration of CTE varied between 100 and 400 mu g ml(-1). The time-kill assay conducted at a CTE concentration of 100 mu g ml(-1) evidenced bactericidal activity against Porphyromonas gingivalis (ATCC 33277) and Peptostreptococcus micros (clinical isolate) within 72 h. CTE at 200 mu g ml(-1) inhibited Porphyromonas gingivalis and Peptostreptococcus micros biofilm formation by at least 50 %. A combination of CTE with chlorhexidine dichlorohydrate did not prompt any synergistic effects. The colony-forming assay conducted on V79 cells showed that CTE was cytotoxic at concentrations above 156 mu g ml(-1). CTE exerted mutagenic effect on V79 cells, but the micronucleus test conducted on Swiss mice and the Ames test did not reveal any mutagenicity. Therefore, the use of standardized and safe extracts could be an important strategy to develop novel oral care products with antibacterial action. These extracts could also serve as a source of compounds for the discovery of new promising biomolecules. Univ Franca UNIFRAN, Lab Res Appl Microbiol, BR-14404600 Sao Paulo, Brazil Univ Franca UNIFRAN, Lab Mutagenesis, BR-14404600 Sao Paulo, Brazil State Univ Sao Paulo, Sch Pharmaceut Sci, BR-14801902 Sao Paulo, Brazil Univ Sao Paulo, Sch Pharmaceut Sci, BR-14040903 Sao Paulo, Brazil State Univ Sao Paulo, Sch Pharmaceut Sci, BR-14801902 Sao Paulo, Brazil FAPESP: 2011/13630-7 FAPESP: 2012/25237-0 FAPESP: 2012/08335-9

Faculty of Pharmacy, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil(Received 30 August 2010; Accepted 10 January 2011)Abstract: Baccharin (3-prenyl-4-(dihydrocinnamoyloxy)cinnamic acid) is an important chemical compound isolated from theaerial parts of Baccharis dracunculifolia DC (Asteraceae), a native plant of South America, and the most important plantsource of Brazilian green propolis. The present study was designed to investigate the ability of baccharin to modulate thegenotoxic effects induced by doxorubicin and methyl methanesulphonate in male Swiss mice using the micronucleus andcomet assays, respectively. The different doses of baccharin [0.12, 0.24 and 0.48 mg⁄kg body-weight (b.w.)] were administeredsimultaneously to doxorubicin (micronucleus test; 15 mg⁄kg b.w.) and to methyl methanesulphonate (comet assay; 40 mg⁄kgb.w.). The results showed a significant decrease in the frequency of micronucleated polychromatic erythrocytes in animals trea-ted with baccharin and doxorubicin compared to animals that received only doxorubicin. This reduction ranged from 39.8%to 50.7% in the micronucleus test. The extent of DNA damage in liver cells was significantly lower in animals treated with dif-ferent concentrations of baccharin combined with methyl methanesulphonate in comparison with the damage observed foranimals treated only with methyl methanesulphonate. These differences resulted in a significant reduction in the extent ofDNA damage, which ranged from 47.8% to 60.6%.

The oral cavity, which harbors more than 750 bacterial species, is one of the most diverse sites of the human body. Some of these bacteria have been associated with oral diseases, such as dental caries and endodontic infections. We report on the antimicrobial and cytotoxic activities of Copaifera oblongifolia oleoresin against bacteria that cause caries and endodontic infections. The aim of this study is to determine the minimum (MIC) and the bactericidal (MBC) inhibitory concentrations as well as the biofilm inhibition ability (through determination of MBIC 50 ) of the C. oblongifolia oleoresin. This study also investigated the bactericidal kinetics (time-kill curves) and the synergistic effect of the C. oblongifolia oleoresin. Additionally, this study evaluated the cytotoxic activity of the oleoresin toward V79 cells by means of the colony-forming assay. The C. oblongifolia oleoresin gave promising MIC and MBC values, which ranged from 25 to 200 μg/mL. Analysis of the MBIC 50 values of the oleoresin revealed it displayed biofilm inhibitory activity against all the assayed bacteria. Analysis of the bactericidal kinetics showed different behaviors of the oleoresin against the tested bacteria at the different time intervals and concentrations assayed in this study. An additive effect of the oleoresin with chlorhexidine dihydrochloride occurred only for S. mitis and A. actinomycetemcomitans. The C. oblongifolia oleoresin showed cytotoxic activity at concentrations ≥ 625 μg/mL.

Solanum cernuum Vell is a Brazilian shrub or small tree, restricted to Southeast states of the country. The leaves are commercialized as "panacéia" and indicated for the treatment of urinary disorders, gonorrhea, scabies, skin diseases and as desobstruent, diuretic and antiarrhythmic. The hydroalcholic extract is active in the treatment of gastric ulcer. The aim of this study was to evaluate the genotoxic and antigenotoxic potential of S. cernuum hydroalcoholic extract (SC) in Swiss mice by micronucleus and comet assays. The animals were treated by gavage with the doses of 500, 1000 and 2000mg/kg body weight (b.w.). For antigenotoxicity assessment, the doses of 15, 30, 60, 120 and 240mg/kg b.w SC were administered simultaneously with the mutagen methyl methanesulfonate (MMS, 40mg/kg b.w., i.p.). The results showed that the SC was not genotoxic in both micronucleus and comet assays. On the other hand, the treatment with the lowest dose of SC (15mg/kg b.w.) plus MMS showed a statistically significant reduction in the frequency of micronuclei compared to treatment only with MMS. For the comet assay, significant reduction in extensions of DNA damage was observed in all treatments with SC combined with MMS in comparison with only MMS. The antigenotoxic activity observed for the SC may be due to the antioxidant potential of the compounds present in the extract such as guanidine alkaloids and flavonoids.

The fruits of Solanum lycocarpum, known as wolf-fruit, are used in folk medicine, and because of that we have evaluated both the genotoxic potential of its glycoalkaloidic extract (SL) and its influence on the genotoxicity induced by methyl methanesulfonate. Furthermore, the potential blocking effect of SL intake in the initial stage of colon carcinogenesis in Wistar rats was investigated in a short-term (4-week) bioassay using aberrant crypt foci (ACF) as biomarker. The genotoxic potential was evaluated using the Swiss mice peripheral blood micronucleus test. The animals were treated with different doses of SL (15, 30 and 60 mg/kg b.w.) for 14 days, and the peripheral blood samples were collected at 48 h, 7 days and 14 days after starting the treatment. For antigenotoxicity assessment, MMS was administered on the 14th day, and after 24 h the harvesting of bone marrow and liver cells was performed, for the micronucleus and comet assays, respectively. In the ACF assay, male Wistar rats were given four subcutaneous injections of the carcinogen 1,2-dimethylhydrazine (DMH, 40 mg/kg b.w.), twice a week, during two weeks to induce ACF. The treatment with SL (15, 30 and 60 mg/kg b.w.) was given for four weeks during and after carcinogen treatment to investigate the potential beneficial effects of SL on DMH-induced ACF. The results demonstrated that SL was not genotoxic in the mouse micronucleus test. In animals treated with SL and MMS, the frequencies of micronucleus and extensions of DNA damage were significantly reduced in comparison with the animals receiving only MMS. Regarding the ACF assay, SL significantly reduced the frequency of ACF induced by DMH.

Roupala montana Aubl. (Proteaceae) is a typical savannah species and native to tropical South America that has a moderate mortality for adult forms of Schistossoma mansoni. Because this species has been little studied, the aim of this investigation was to evaluate the influence of R. montana extract on DNA damage induced by methyl methanesulfonate (MMS) in peripheral blood cells and liver of Swiss mice using the micronucleus and comet assay, respectively. R. montana dichloromethane extract was prepared from a stock solution (0.5 mg/mL) in 5% dimethyl sulfoxide in water. Animals received a single dose of different concentrations of R. montana (5, 10 and 20 mg/kg body weight) by gavage (0.5 mL/animal). For antigenotoxicity assessment, different concentrations of R. montana were administered simultaneously with MMS diluted in water (40 mg/kg, intraperitoneally; 0.3 mL/animal). Peripheral blood and hepatocyte samples were obtained 48 and 24 h after treatment, respectively. Results showed that R. montana administered alone indicated the absence of genotoxicity in the mouse micronucleus or comet assay. On the other hand, administration of different doses of R. montana concomitantly with MMS led to a significant reduction in frequency of micronucleated polychromatic erythrocytes and DNA damage, when compared to the group treated only with MMS. Further, for the micronucleus assay, the gradual increase of R. montana concentration led to a proportional increase in the reduction of genotoxicity induced by MMS, indicating a dose-response relationship.

Styrax camporum Pohl is a tall shrub or a tree with small white flowers, which grows in the states of Sao Paulo and Minas Gerais and is popularly used for the treatment of gastroduodenal diseases. Considering this last fact, the aim of this study was to evaluate the genotoxic potential of S. camporum hydroalcoholic extract and its influence on genotoxicity induced by doxorubicin and methyl methanesulfonate in Swiss mice using the micronucleus and comet assays, respectively. The animals were treated by gavage with different doses of the extract (250, 500, and 1000 mg/kg body weight). For antigenotoxicity assessment, different doses of the S. camporum extract were administered simultaneously with doxorubicin (micronucleus test; 15 mg/kg) and methanesulfonate (comet assay; 40 mg/kg). The results showed that the S. camporum extract itself was not genotoxic in the mouse micronucleus or comet assay. The number of micronucleated polychromatic erythrocytes was significantly lower in animals treated with the S. camporum extract and doxorubicin when compared to animals treated only with doxorubicin. In the comet assay, the S. camporum extract, at the doses tested, significantly reduced the extent of DNA damage in liver cells induced by methanesulfonate. The putative activity of the active compounds of S. camporum extract may explain the effect of this plant on genotoxicity induced by doxorubicin and methanesulfonate.

Baccharin is one of the major chemical compounds isolated from the aerial parts of Baccharis dracunculifolia DC (Asteraceae), a native plant of South America and the most important botanical source of the Brazilian green propolis that has been used in alternative medicine to treat inflammation, liver disorders, and stomach ulcers. The present study was carried out in V79 cells to determine the possible genotoxic and antigenotoxic activities of baccharin utilizing comet and micronucleus assays, where 2 known mutagenic agents with different mechanisms of DNA damage were used as positive controls. The V79 cells were treated with concentrations of baccharin (0.25, 0.5, 1.0, and 2.0 μg/mL) and for to investigate the antigenotoxicity these concentrations were associated with methyl methanesulfonate (MMS; 200 μM-comet assay and 400 μM-micronucleus assay) or hydrogen peroxide (H(2)O(2;) 50 μM-comet assay and 100 μM-micronucleus assay). Statistically significant differences in the rate of DNA damage were observed in cultures treated with the highest concentration of baccharin when compared to the control group, but this difference was not found in the micronucleus assay. The results also showed that the frequencies of DNA damage and micronuclei induced by MMS and H(2)O(2) were significantly reduced after treatment with baccharin. The baccharin showed a chemoprevention effect and can be the chemical compound responsible for the antigenotoxicity also demonstrated by the B. dracunculifolia. The antioxidant potential of baccharin may be related to its chemoprevention activity induced against both genomic and chromosomal damages.