Selective anticancer effects of Serjania marginata Casar. extract in gastric cells are mediated by antioxidant response.

Gastric cancer is the fifth most common malignancy worldwide. Serjania marginata Casar. (SM) displays anti-inflammatory properties and has been used to treat gastrointestinal disorders. In the current study, we examined whether the hydroethanolic extract of SM leaves exerted cytotoxic, mutagenic, and protective effects in non-tumor gastric epithelium cells (MNP01) and gastric adenocarcinoma cells (ACP02) in vitro and analyzed whether its action was selective. Initially, cell viability (MTT assay), cell cycle kinetics (flow cytometry), and cell proliferation (total protein content) were analyzed. In addition, genomic instability (cytokinesis-block micronucleus cytome assay), anti/pro-oxidant status (CM-H2 DCFDA probe), and transcriptional expression (RT-qPCR) of genes related to cell cycle, cell death, and antioxidant defense were also evaluated. The SM extract was cytotoxic toward MNP01 and ACP02 cells at concentrations greater than 300 and 100 µg·ml-1 , respectively, and decreased protein content only toward ACP02 cells at 200 µg ml-1 . In ACP02 cells, the SM extract at 100 µg·ml-1 associated with doxorubicin (DXR; 0.2 µg ml-1 ) clearly promoted cell cycle arrest at the G2/M phase. The extract alone was not mutagenic to either cell type and reversed DXR-induced DNA damage and H2 O2 -induced oxidative stress in MNP01 cells. The gene expression experiments showed that SM hydroethanolic extract exerts an antioxidant response via NFE2L2 activation in non-tumor gastric cells, and cell cycle arrest (G2/M) in ACP02 gastric cancer cells via the TP53 pathway. The selective action of SM indicates that it is a promising therapeutic agent to treat gastric diseases and merits further studies.

Preventive activity of Copaifera langsdorffii Desf. leaves extract and its major compounds, afzelin and quercitrin, on DNA damage in in vitro and in vivo models.

Copaifera langsdorffii Desf. is a plant found in South America, especially in Brazil. Oleoresin and the leaves of this plant is used as a popular medicinal agent. However, few studies on the chemical composition of aerial parts and related biological activities are known. This study aimed to examine the cytotoxic, genotoxic, and antigenotoxic potential of C. langsdorffii aerial parts hydroalcoholic extract (CLE) and two of its major compounds afzelin and quercitrin. The cytotoxic and antigenotoxic potential of CLE was determined as follows: 1) against genotoxicity induced by doxorubicin (DXR) or methyl methanesulfonate (MMS) in V79 cells; 2) by direct and indirect-acting mutagens in Salmonella typhimurium strains; and 3) by MMS in male Swiss mice. The protective effects of afzelin and quercitrin against DXR or MMS were also evaluated in V79 and HepG2 cells. CLE was cytotoxic as evidenced by clonogenic efficiency assay. Further, CLE did not induce a significant change in frequencies of chromosomal aberrations and micronuclei; as well as number of revertants in the Ames test demonstrating absence of genotoxicity. In contrast, CLE was found to be antigenotoxic in mammalian cells. The results also showed that CLE exerted inhibitory effect against indirect-acting mutagens in the Ames test. Afzelin and quercitrin did not reduce genotoxicity induced by DXR or MMS in V79 cells. However, treatments using afzelin and quercitrin decreased MMS-induced genotoxicity in HepG2 cells. The antigenotoxic effect of CLE observed in this study may be partially attributed to the antioxidant activity of the combination of major components afzelin and quercitrin.

Phytochemical Profile, and Antiproliferative and Proapoptotic Effects of Pouteria ramiflora (Mart.) Radlk. Leaf Extract, and Its Synergism with Cisplatin in HepG2 Cells.

Different species of the genus Pouteria have been used in folk medicine for the treatment of inflammation, fever, ulcers, diabetes, and diarrhea. We analyzed the phytochemical profile of the hydroethanolic extract from Pouteria ramiflora leaves by electrospray ionization ion trap tandem mass spectrometry and high-performance liquid chromatography-diode array detection, and examined whether it alone and in combination with cisplatin interfered with cell proliferation and death processes in HepG2 (human hepatocellular carcinoma) and FGH (human gingival fibroblasts) cells. Five compounds were identified in the extract: gallic acid, myricetin-3-O-α-l-arabinopyranoside, quercetin-3-O-ß-d-galactopyranoside, myricetin-3-O-α-l-rhamnopyranoside, and myricetin-3-O-ß-d-galactopyranoside. The extract was cytotoxic to both cell lines by inducing apoptotic cell death and acted in synergy with cisplatin; such effect was stronger in HepG2 cells than in FGH cells, demonstrating some selectivity to tumor cells. In HepG2 cells, the extract exerted antiproliferative effect mediated by induction of cell cycle arrest at the S and G2/M phases. Association of the extract with cisplatin enhanced the latter's antiproliferative effect, arrested the cell cycle at the S phase by CDK2 modulation, and reduced the number of anti-cyclin D1-stained HepG2 cells. Simultaneous treatment with the extract and cisplatin increased the latter's cytotoxicity, apoptotic cell death, and BAX expression in HepG2 cells. Altogether, the results reported herein indicate that P. ramiflora extract is a possible adjuvant to cancer therapy, which can circumvent the cisplatin-mediated resistance mechanisms in cancer cells.

Activity of silver nanoparticles on prokaryotic cells and Bothrops jararacussu snake venom.

Nanoparticle-conjugated venom-toxins of venomous animals and its therapeutic efficacy against emerging or neglecting diseases is a promising strategy. In this study, silver nanoparticles (AgNPs ∼50 nm, 0.081 mg mL-1) were studied against the neuromuscular blockade, myotoxic effects induced by Bothrops jararacussu venom (60 µg mL-1) and also against prokaryotic cells. The neurotoxicity was evaluated on ex vivo mouse phrenic nerve-diaphragm using traditional myographic technique, able to obtain functional contractile responses and to check the neurotransmission. The myotoxicity on mammalian cells was evaluated in muscles resulting from pharmacological assays using routine histological techniques and light microscopy. The toxicity to prokaryotic cells was evaluated on Salmonella typhimurium TA100 without metabolic activation. The in vitro preincubation model between AgNPs and venom was enough to abolish toxic effects of B. jararacussu venom, but mammalian cells were highly sensitive to AgNPs more than prokaryotic cells, by acting as dose-independently and dose-dependently parameters, respectively. These results allowed us to conclude that AgNPs showed promising activity as antivenom agent but for its safer use, the toxicity should be evaluated on experimental animals.

Pouteria ramiflora (Mart.) Radlk. extract: Flavonoids quantification and chemopreventive effect on HepG2 cells.

Pouteria ramiflora (Mart.) Radlk., popularly known as curriola, is commonly used in Brazil as medicinal plant to treat worm infections, dysentery, pain, inflammation, hyperlipidemia, and obesity. At present the safety of this extract when used therapeutically in human remains to be determined. Thus, the aim of this study was to examine cytotoxicity, antiproliferative, and antimutagenic actions of this extract. The hydroalcoholic extract from P. ramiflora leaves consisted of flavonoids identified and quantified as myricetin-3-O-ß-D-galactopyranoside (13.55 mg/g) and myricetin-3-O-α-L-rhamnopyranoside (9.61 mg/g). The extract exhibited cytotoxicity at concentrations higher than 1.5 µg/ml in human hepatocarcinoma (HepG2)and 2.5 µg/ml in non-tumoral primary gastric (GAS) cells using the MTT assay, and at concentrations higher than 3 µg/ml in HepG2 and 3.5 µg/ml in GAS cells by the neutral red assay. The extract did not show antiproliferative effect as evidenced by the nuclear division index (NDI). However, in the presence of benzo[a]pyrene (BaP) (positive control), an enhanced cytostatic effect in the NDI and flow cytometry was noted. It is of interest that when the extract was co-incubated with BaP a significant decrease in DNA damage was observed indicating an antimutagenic action. This protective effect might be attributed to myricetin and gallic acid found in P. ramiflora extract. The low cytotoxicity action and protective effect observed in the present study encourage further studies regarding other biological effects of P. ramiflora, as well as its potential use as a chemopreventive agent.

Phytochemical study and evaluation of cytotoxicity, mutagenicity, cell cycle kinetics and gene expression of Bauhinia holophylla (Bong.) Steud. in HepG2 cells in vitro.

Bauhinia holophylla (Bong.) Steud. (Fabaceae) is a plant used in Brazilian folk medicine to treat diabetes and inflammation. This study evaluated the phytochemical properties, cytotoxic, apoptotic, mutagenic/antimutagenic effects and alterations in gene expression (RNAm) in HepG2 cells treated with the B. holophylla extract. The phytochemical profile highlight the presence of flavonoids isorhamentin and quercetin derivates. The MTT assay was used to evaluate the cytotoxicity of different concentrations for different treatment times. Three concentrations (7.5, 15, 30 µg/mL) were chosen for assessment of apoptosis (AO/EB), mutagenicity (micronucleus), and cell cycle kinetics (flow cytometry). Thereafter, the concentration of 7.5 µg/mL was chosen to evaluate the protective effects against DNA damage induced by benzo[a]pyrene (B[a]P). At concentrations higher than 7.5 µg/mL (between 10 and 50 µg/mL), the extract was cytotoxic, induced apoptosis, and caused antiproliferative effects. However, it did not induce micronucleus and a reduction of apoptotic and micronucleated cells was observed in treatments that included the extract and B[a]P. The protective effect is attributable to the presence of flavonoids, described as antioxidants, inhibitors of DNA adduct and activators of detoxifying enzymes. The results of the present study such as absence of cytotoxic and mutagenic effects and protective effects against known carcinogens suggest that B. holophylla has potential for use soon as herbal medicine.

Antigenotoxicity properties of Copaifera multijuga oleoresin and its chemical marker, the diterpene (-)-copalic acid.

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 µg/ml-MN assay; 0.39-3.12 mg/plate-Ames test) or CA (2.42; 4.84, or 9.7 µg/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. ABBREVIATIONS: 2-AA, 2-anthramine; 2-AF, 2-aminofluorene; AFB1, aflatoxin B1; B[a]P, benzo[a]pyrene; BOD, biological oxygen demand; BPDE, benzo[a]pyrene-7,8-diol-9,10-epoxide; CA, (-)-copalic acid; CMO, oleoresin of Copaifera multijuga, DMEM, Dulbecco`s Modified Eagles`s Medium; DMSO, dimethylsulfoxide; EMBRAPA, Brazilian agricultural research corporation; GC-MS, gas chromatography-mass spectrometry; HAM-F10, nutrient mixture F-10 Ham; HPLC, high performance liquid chromatography; LC-MS, liquid chromatography-mass spectrometry; MI, mutagenic index; MMC, mitomycin C; MMS, methyl methanesulfonate; MN, micronucleus; MNPCE, micronucleated polychromatic erythrocyte; NCE, normochromatic erythrocyte; NDI, nuclear division index; NMR, nuclear magnetic resonance; NPD, 4-nitro-o-phenylenediamine; PBS, phosphate-buffered saline; PCE, polychromatic erythrocyte; SA, sodium azide; V79, Chinese hamster lung fibroblast.

In vitro toxicological assessment of Arrabidaea brachypoda (DC.) Bureau: Mutagenicity and estrogenicity studies.

Arrabidaea brachypoda (DC.) Bureau is a shrub native Cerrado, known as "cipó-una", "tintureiro" or "cervejinha do campo" and popularly used in Southeastern and Northeastern Brazil to treatment of kidney stones and painful joints (arthritis). Nevertheless, scientific information regarding this species is scarce, and there are no reports related to its possible estrogenic and mutagenic effects. Thus, the principal objective of this study was to assess the mutagenic and estrogenic activities of the hydroalcoholic extracts of the leaves, stalks, roots, their respective fractions and isolated compounds of A. brachypoda. The mutagenic activity was evaluated by the Ames test on Salmonella typhimurium strains TA98, TA97a, TA100 and TA102, in the absence (-S9) and presence (+S9) of metabolic activation system. In the RYA was used Saccharomyces cerevisiae engineered strain BY4741 (MATaura3Δ0 leu2Δ0 his3Δ1 met15Δ0) which reproduce the natural pathway of genetic control by estrogens in vertebrate cells; it has the advantage of its simplicity and a high throughput. All extracts and aqueous fraction of leaves A. brachypoda were mutagenic. The crude extract is more active than the fraction, suggesting a synergic effect. Only hydroalcoholic extracts of leaves and roots of A. brachypoda showed significant estrogenic activity, with ERα-dependent transcriptional activation activity. The obtained results in this study showed the presence of compounds capable of interacting with the estrogen receptor and to induce damage in the genetic material. Thus, we demonstrated the risk which the population is subjected due to indiscriminate use of extracts without detailed study.

Effects of indirubin and isatin on cell viability, mutagenicity, genotoxicity and BAX/ERCC1 gene expression.

CONTEXT: Indigofera suffruticosa Miller (Fabaceae) and I. truxillensis Kunth produce compounds, such as isatin (ISA) and indirubin (IRN), which possess antitumour properties. Their effects in mammalian cells are still not very well understood. OBJECTIVE: We evaluated the activities of ISA and/or IRN on cell viability and apoptosis in vitro, their genotoxic potentials in vitro and in vivo, and the IRN- and ISA-induced expression of ERCC1 or BAX genes. MATERIALS AND METHODS: HeLa and/or CHO-K1 cell lines were tested (3 or 24 h) in the MTT, Trypan blue exclusion, acridine orange/ethidium bromide, cytokinesis-blocked micronucleus (CBMN) and comet (36, 24 and 72 h) tests after treatment with IRN (0.1 to 200 µM) or ISA (0.5 to 50 µM). Gene expression was measured by RT-qPCR in HeLa cells. Swiss albino mice received IRN (3, 4 or 24 h) by gavage (50, 100 and 150 mg/kg determined from the LD50 - 1 g/kg b.w.) and submitted to comet assay in vivo. RESULTS: IRN reduced the viability of CHO-K1 (24 h; 5 to 200 µM) and HeLa cells (10 to 200 µM), and was antiproliferative in the CBMN test (CHO-K1: 0.5 to 10 µM; HeLa: 5 and 10 µM). The drug did not induce apoptosis, micronucleus neither altered gene expression. IRN and ISA were genotoxic for HeLa cells (3 and 24 h) at all doses tested. IRN (100 and 150 mg/kg) also induced genotoxicity in vivo (4 h). CONCLUSION: IRN and ISA have properties that make them candidates as chemotherapeutics for further pharmacological investigations.

Evaluation of Betulin Mutagenicity by Salmonella/Microsome Test.

Purpose: Betulin is a pentacyclic triterpene found in the outer barks of innumerous plants. This secondary metabolite is easily isolated from plants with the major interest in converting it to betulinic acid, which pharmacological properties were much more exploited than betulin. But, investments in the own betulin have been grown since no chemical step is necessary. In this study we focused the precursor betulin in order to evaluate its mutagenicity by Salmonella/microsome assay (Ames test). Methods: The Ames test was carried out using a commercial betulin exposed to Salmonella typhimurium strains TA98, TA100, TA102, and TA97a, in experiments with (+S9) and without (-S9) metabolic activation. Results: Betulin was unable to increase the number of revertants (+S9 and -S9 metabolic activation) showing the absence of any mutagenic effect by Ames test. Conclusion: This study allowed attribute safety to betulin being important for exploiting its pharmacological uses.

Assessment of the antibacterial, cytotoxic and mutagenic potential of the phenolic-rich hydroalcoholic extract from Copaifera trapezifolia Hayne leaves.

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 µg ml-1. The time-kill assay conducted at a CTE concentration of 100 µg ml-1 evidenced bactericidal activity against Porphyromonas gingivalis (ATCC 33277) and Peptostreptococcus micros (clinical isolate) within 72 h. CTE at 200 µg 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 µg 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.

In vitro evaluation of the cyto-genotoxic potential of Ruthenium(II) SCAR complexes: a promising class of antituberculosis agents.

Tuberculosis is a top infectious disease killer worldwide, caused by the bacteria Mycobacterium tuberculosis. Increasing incidences of multiple drug-resistance (MDR) strains are emerging as one of the major public health threats. However, the drugs in use are still incapable of controlling the appalling upsurge of MDR. In recent years a marked number of research groups have devoted their attention toward the development of specific and cost-effective antimicrobial agents against targeted MDR-Tuberculosis. In previous studies, ruthenium(II) complexes (SCAR) have shown a promising activity against MDR-Tuberculosis although few studies have indeed considered ruthenium toxicity. Therefore, within the preclinical requirements, we have sought to determine the cyto-genotoxicity of three SCAR complexes in this present study. The treatment with the SCARs induced a concentration-dependent decrease in cell viability in CHO-K1 and HepG2 cells. Based on the clonogenic survival, SCAR 5 was found to be more cytotoxic while SCAR 6 exhibited selectivity action on tumor cells. Although SCAR 4 and 5 did not indicate any mutagenic activity as evidenced by the Ames and Cytokinesis block micronucleus cytome assays, the complex SCAR 6 was found to engender a frameshift mutation detected by Salmonella typhimurium in the presence of S9. Similarly, we observed a chromosomal damage in HepG2 cells with significant increases of micronuclei and nucleoplasmic bridges. These data indicate that SCAR 4 and 5 complexes did not show genotoxicity in our models while SCAR 6 was considered mutagenic. This study presented a comprehensive genotoxic evaluation of SCAR complexes were shown to be genotoxic in vitro. All in all, further studies are required to fully elucidate how the properties can affect human health.

Chemical and biological characterisation of Machaerium hirtum (Vell.) Stellfeld: absence of cytotoxicity and mutagenicity and possible chemopreventive potential.

Machaerium hirtum (Vell.) Stellfeld (M.hirtum) is a plant known as 'jacarandá-bico-de-pato' whose bark is commonly used against diarrhea, cough and cancer. The aim of this study was to phytochemically characterise the hydroethanolic extract of this plant, investigate its antimutagenic activities using the Ames test and evaluate its effects on cell viability, genomic instability, gene expression and cell protection in human hepatocellular carcinoma cells (HepG2). Antimutagenic activity was assessed by simultaneous pre- and post-treatment with direct and indirect mutagens, such as 4-nitro-o-phenylenediamine (NPD), mitomycin C (MMC), benzo[a]pyrene (B[a]P) and aflatoxin B1 (AFB1), using the Ames test, cytokinesis blocking micronucleus and apoptosis assays. Only 3 of the 10 concentrations evaluated in the MTT assay were cytotoxic in HepG2 cells. Micronucleated or apoptotic cells were not observed with any of the tested concentrations, and there were no mutagenic effects in the bacterial system. However, the Nuclear Division Index and flow cytometry data showed a decrease in cell proliferation. The extract showed an inhibitory effect against direct (NPD) and indirect mutagens (B[a]P and AFB1). Furthermore, pre- and post-treated cells showed significant reduction in the number of apoptotic and micronucleated cells. This effect is not likely to be associated with the modulation of antioxidant genes, as shown by the RT-qPCR results. Six known flavonoids were identified in the hydroethanolic extract of Machaerium hirtum leaves, and their structures were elucidated by spectroscopic and spectrophotometric methods. The presence of the antioxidants apigenin and luteolin may explain these protective effects, because these components can inhibit the formation of reactive species and prevent apoptosis and DNA damage. In conclusion, the M.hirtum extract showed chemopreventive potential and was not hazardous at the tested concentrations in the experiments presented here. Moreover, this extract should be investigated further as a chemopreventive agent.

Antimutagenicity and induction of antioxidant defense by flavonoid rich extract of Myrcia bella Cambess. in normal and tumor gastric cells.

ETHNOPHARMACOLOGICAL RELEVANCE: The Brazilian "Cerrado" is an important source of natural products, such as Myrcia bella Cambess (MB, also known as "mercurinho"). MB leaves are popularly used for the treatment of diabetes and gastrointestinal disorders; however, only its hypoglycemic activity has been experimentally described. AIM OF THE STUDY: Because MB is used to treat gastrointestinal disorders, the present study characterized biological activities of hydroalcoholic MB extract in human normal and tumor gastric cells. MATERIALS AND METHODS: Cytotoxic, antiproliferative, genotoxic and protective effects were evaluated, as well as the effects of the MB extract on gene expression. RESULTS: The MB extract induced cytotoxicity in tumor cells at lower concentrations compared with normal cells as assessed by the MTT assay. Moreover, the MB extract induced necrosis based on acridine orange/ethidium bromide staining. An antiproliferative effect was evidenced through an arrest in the G2/M phase detected by flow cytometry and a decrease in the nuclear division index using the cytokinesis-block micronucleus cytome assay. Cells treated with MB extract combined with doxorubicin (DXR) showed increased NUBDs, which may be related to the gene amplification of CCND1. Antimutagenic effects were also observed and may be associated with the antioxidant activities detected using the CM-H2DCFDA probe. CONCLUSIONS: Our findings showed the following: (a) high concentrations of MB induced cytotoxicity and cell death by necrosis; (b) its antiproliferative effect was associated with G2/M arrest; and (c) its antioxidant activity could be responsible for the observed antimutagenic effects and for protective effects against gastrointestinal disorders previously described to MB. Although these effects are not specific to normal or tumor cells, they provide a panel of biological activities for further exploration.

Does the gastroprotective action of a medicinal plant ensure healing effects? An integrative study of the biological effects of Serjania marginata Casar. (Sapindaceae) in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Serjania marginata (Sapindaceae), a medicinal plant commonly found in the Brazilian Cerrado, Paraguay, Bolivia and Argentina, is also known as "cipó-uva" or "cipó-timbó". Ethnopharmacological studies indicate that the leaves from this medicinal plant are used in folk medicine to treat gastric pain. The overall objective of this study was to evaluate the gastroprotective and healing effect of the hydroalcoholic extract obtained from S. marginata (HESM) leaves using rodent experimental models. As part of the integrative study of this medicinal plant, we also evaluated the acute toxicity, antimicrobial, antidiarrheal, (anti)mutagenic, and hemodynamic effects. MATERIAL AND METHODS: We performed a pharmacological study to test the acute toxicity and antimutagenic effect (Ames assay) of the HESM. The HESM was tested against different necrosis-promoting agents and experimental manipulations, such as absolute ethanol, cysteamine, pyloric ligature, and ischemia-reperfusion (I/R) injury. The gastroprotective effect of the HESM was assessed by analyzing the gastric juice (volume, pH, total acidity) and the mucus in the gastric mucosa from rats. We assessed the levels of NO, sulfhydryl compounds, PGE2, vanilloid receptor, glutathione (GSH), and malondialdehyde (MDA), as well as the myeloperoxidase (MPO) activity. The gastric healing effects of the HESM were evaluated during 7 or 14 days of treatment. The intestinal motility, antidiarrheal action, and antibacterial effects (microdilution methods) of the HESM were also evaluated. RESULTS: The phytochemical analysis of the HESM revealed the presence of saponins, flavonoid glycosides, and tannins. The extract exhibited no sign of acute toxicity or mutagenic effect in vitro. In contrast, this extract exhibited a protective effect against the mutagenic action of direct- and indirect-acting mutagens. Only the oral administration of HESM (250mg/kg) significantly decreased the severity of gastric damage induced by ethanol (60.13%) and I/R (58.31%). The HESM exerts its gastroprotective effects by decreasing the MPO and MDA activities in the gastric tissue and by increasing the amount of adherent mucus covering the gastric mucosa. In vitro, the extract also displayed evident antimicrobial effects against Helicobacter pylori. However, the preventive effect of the HESM was not accompanied by an ulcer-healing effect. The treatment with HESM (14 days) significantly increased gastric lesions in 99% of the tested animals compared with the control group. This result represents a highly relevant piece of evidence that should resonate as an alert against the chronic use of this medicinal plant as an antiulcer in folk medicine. CONCLUSIONS: Despite the anti-H. pylori and gastroprotective actions of S. marginata in experimental models, the gastric injuries aggravation induced after chronic treatment with the HESM argues against the use of this plant species in folk medicine.

Mutagenicity and chemopreventive activities of Astronium species assessed by Ames test.

In the neotropical savannah, Astronium species are used in popular medicine to treat allergies, inflammation, diarrhea and ulcers. Given that natural products are promising starting points for the discovery of novel potentially therapeutic agents, the aim of the present study was to investigate the mutagenic and antimutagenic activities of hydroalcoholic extracts of Astronium spp. The mutagenicity was determined by the Ames test on Salmonella typhimurium strains TA98, TA97a, TA100 and TA102. The antimutagenicity was tested against the direct-acting and indirect-acting mutagens. The results showed that none of the extracts induce any increase in the number of revertants, demonstrating the absence of mutagenic activity. On the other hand, the results on the antimutagenic potential showed a moderate inhibitory effect against NPD and a strong protective effect against B[a]P and AFB1. This study highlights the importance of screening species of Astronium for new medicinal compounds. The promising results obtained open up new avenues for further study and provide a better understanding the mechanisms by which these species act in protecting DNA from damage. However, further pharmacological and toxicological investigations of crude extracts of Astronium spp., as well as of its secondary metabolites, are necessary to determine the mechanism(s) of action to guarantee their safer and more effective application to human health.

In vitro assessment of mutagenic and genotoxic effects of coumarin derivatives 6,7-dihydroxycoumarin and 4-methylesculetin.

Coumarins are naturally occurring compounds, widely distributed throughout the plant kingdom (Plantae), and possess important pharmacological properties, including inhibition of oxidative stress. In this context, newly synthesized coumarin compounds are being produced due to their potent antioxidant activities. Therefore, the aim of the present study was to determine the in vitro cytotoxic, mutagenic, and genotoxic effects of 6,7-dihydroxycoumarin (6,7-HC) and 4-methylesculetin (4-ME) using the Salmonella/microsome test and in cultured human lymphocytes the comet assay and micronucleus test. The three coumarin derivatives concentrations evaluated in comet and MN assays were 2, 8, and 32 µg/mL, selected through a preliminary trypan blue-staining assay. In the Ames test, the 5 concentrations tested were 62.5, 125, 250, 500, and 750 µg/plate. Positive (methyl methane-sulfonate, MMS) and negative (dimethyl sulfoxide, DMSO) control groups were also included in the analysis. Our results showed that 4-ME induced greater cytotoxicity at high concentrations than 6,7-HC. In addition, both compounds were not mutagenic in the Ames test and not genotoxic or clastogenic/aneugenic in cultured human lymphocytes.

Characterization and quantification of the compounds of the ethanolic extract from Caesalpinia ferrea stem bark and evaluation of their mutagenic activity.

Caesalpinia ferrea Martius has traditionally been used in Brazil for many medicinal purposes, such as the treatment of bronchitis, diabetes and wounds. Despite its use as a medicinal plant, there is still no data regarding the genotoxic effect of the stem bark. This present work aims to assess the qualitative and quantitative profiles of the ethanolic extract from the stem bark of C. ferrea and to evaluate its mutagenic activity, using a Salmonella/microsome assay for this species. As a result, a total of twenty compounds were identified by Flow Injection Analysis Electrospray Ionization Ion Trap Mass Spectrometry (FIA-ESI-IT-MS/MSn) in the ethanolic extract from the stem bark of C. ferrea. Hydrolyzable tannins predominated, principally gallic acid derivatives. The HPLC-DAD method was developed for rapid quantification of six gallic acid compounds and ellagic acid derivatives. C. ferrea is widely used in Brazil, and the absence of any mutagenic effect in the Salmonella/microsome assay is important for pharmacological purposes and the safe use of this plant.

Mutagenicity and antimutagenicity of six Brazilian Byrsonima species assessed by the Ames test.

BACKGROUND: In various regions of Brazil, several species of the genus Byrsonima (Malpighiaceae) are widely used to treat gastrointestinal complications. This genus has about 150 species of shrubs and trees distributed over the entire Neotropical region. Various biological activities have been identified in these plants, especially antioxidant, antimicrobial and topical and systemic anti-inflammatory activities. The aim of this study was to investigate the mutagenicity and antimutagenicity of hydroalcoholic leaf extracts of six species of Byrsonima: B. verbascifolia, B. correifolia, B. coccolobifolia, B. ligustrifolia, B. fagifolia and B. intermedia by the Salmonella microsome assay (Ames test). METHODS: Mutagenic and antimutagenic activity was assessed by the Ames test, with the Salmonella typhimurium tester strains TA100, TA98, TA97a and TA102, with (+S9) and without (-S9) metabolization, by the preincubation method. RESULTS: Only B. coccolobifolia and B. ligustrifolia showed mutagenic activity. However, the extracts of B. verbascifolia, B. correifolia, B. fagifolia and B. intermedia were found to be strongly antimutagenic against at least one of the mutagens tested. CONCLUSIONS: These results contribute to valuable data on the safe use of medicinal plants and their potential chemopreventive effects. Considering the excellent antimutagenic activities extracted from B. verbascifolia, B. correifolia, B. fagifolia and B. intermedia, these extracts are good candidate sources of chemopreventive agents. However, B. coccolobifolia and B. ligustrifolia showed mutagenic activity, suggesting caution in their use.

Characterization and Quantification of Compounds in the Hydroalcoholic Extract of the Leaves from Terminalia catappa Linn. (Combretaceae) and Their Mutagenic Activity.

Terminalia is a genus of Combretaceous plants widely distributed in tropical and subtropical regions. Thus, the aim of this study was to quantify the majority compounds of the hydroalcoholic extract (7 : 3, v/v) of the leaves from T. catappa by HPLC-PDA, chemically characterize by hyphenated techniques (HPLC-ESI-IT-MS(n)) and NMR, and evaluate its mutagenic activity by the Salmonella/microsome assay on S. typhimurium strains TA98, TA97a, TA100, and TA102. The quantification of analytes was performed using an external calibration standard. Punicalagin is the most abundant polyphenol found in the leaves. The presence of this compound as a mixture of anomers was confirmed using HPLC-PDA and (1)H and (13)C NMR. Mutagenic activity was observed in strains TA100 and TA97a. As the extract is a complex mixture of punicalagin, its derivatives, and several other compounds, the observed mutagenicity may be explained in part by possible synergistic interaction between the compounds present in the extract. These studies show that mutagenic activity of T. catappa in the Ames test can only be observed when measured at high concentrations. However, considering the mutagenic effects observed for T. catappa, this plant should be used cautiously for medicinal purposes.