Natural product-based nanomedicine applied to fungal infection treatment: A review of the last 4 years.

Fungal infections are one of the main public health problems, especially in immunocompromised patients, nosocomial environments, patients with chronic diseases, and transplant recipients. These diseases are increasingly frequent and lethal because the microorganism has a high capacity to acquire resistance to available therapy. The main resistance factors are the emergence of new strains and the uncontrolled use of antifungals. It is, therefore, important to develop new methods that contribute to combating fungal diseases in the clinical area. Natural products have considerable potential for the development of new drugs with antifungal activity, mainly due to their biocompatibility and low toxic effect. This promising antimicrobial activity of natural products is mainly due to the presence of flavonoids, terpenes, and quinones, which explains their antifungal potential. Pharmaceutical nanotechnology has been explored to enhance the delivery, selectivity, and clinical efficacy of these products. Nanotechnological systems provide a safe and selective environment for various substances, such as natural products, improving antifungal activity. However, further safety experiments (in vivo or clinical trials) need to be carried out to prove the therapeutic action of natural products, since they may have undesirable, toxic, and mutagenic effects. Therefore, this review article addresses the main nanotechnological methods using natural products for effective future treatment against the main fungal diseases.

Study of antimycobacterial, cytotoxic, and mutagenic potential of polymeric nanoparticles of copper (II) complex.

This study aimed to encapsulate and characterise a potential anti-tuberculosis copper complex (CuCl2(INH)2.H2O:I1) into polymeric nanoparticles (PNs) of polymethacrylate copolymers (Eudragit®, Eu) developed by nanoprecipitation method. NE30D, S100 and, E100 polymers were tested. The physicochemical characterisations were performed by DLS, TEM, FTIR, encapsulation efficiency and, in vitro release studies. Encapsulation of I1 in PN-NE30D, PN-E100, and PN-S100 was 26.3%, 94.5%, 22.6%, respectively. The particle size and zeta potentials were 82.3 nm and -24.5 mV for PNs-NE30D, 304.4 nm and +18.7 mV for PNs-E100, and 517.9 nm and -6.9 mV for PNs-S100, respectively. All PDIs were under 0.5. The formulations showed an I1 controlled release at alkaline pH with 29.7% from PNs-NE30D, 7.9% from PNs-E100 and, 28.1% from PNs-S100 at 1 h incubation. PNs were stable for at least 3 months. Particularly, PNs-NE30D demonstrated moderate inhibition of M. tuberculosis and low cytotoxic activity. None of the PNs induced mutagenicity.

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.

New Silver(I) Coordination Compound Loaded into Polymeric Nanoparticles as a Strategy to Improve In Vitro Anti-Helicobacter pylori Activity.

Helicobacter pylori inhabits the gastric epithelium and can promote the development of gastric disorders, such as peptic ulcers, acute and chronic gastritis, mucosal lymphoid tissue (MALT), and gastric adenocarcinomas. To use nanotechnology as a tool to increase the antibacterial activity of silver I [Ag(I)] compounds, this study suggests a new strategy for H. pylori infections, which have hitherto been difficult to control. [Ag (PhTSC·HCl)2] (NO3)·H2O (compound 1) was synthesized, characterized, and loaded into polymeric nanoparticles (PN1). PN1 had been developed by nanoprecipitation with poly(ε-caprolactone) polymer and poloxamer 407 surfactant. System characterization assays showed that the PNs had adequate particle sizes and ζ-potentials. Transmission electron microscopy confirmed the formation of polymeric nanoparticles (PNs). Compound 1 had a minimum inhibitory concentration for H. pylori of 3.90 µg/mL, which was potentiated to 0.781 µg/mL after loading. The minimum bactericidal concentration of 7.81 µg/mL was potentiated 5-fold to 1.56 µg/mL in PN. Compound 1 loaded in PN1 displayed better activity for H. pylori biofilm formation and mature biofilm. PN1 reduced the toxicity of compound 1 to MRC-5 cells. Loading compound 1 into PN1 inhibited the mutagenicity of the free compound. In vivo, the system allowed survival of Galleria mellonella larvae at a concentration of 200 µg/mL. This is the first demonstration of the antibacterial activity of a silver complex enclosed in polymeric nanoparticles against H. pylori.

Cyto-genotoxic evaluation of novel anti-tubercular copper (II) complexes containing isoniazid-based ligands.

Considering the promising previous results of Cu (II) complexes with isoniazid active ligand against Mycobacterium tuberculosis, the main causative agent of tuberculosis, novel biological assays evaluating its toxicogenic potential were performed to ensure the safe use. The genotoxicity/mutagenicity of the complexes CuCl2(INH)2.H2O (I1), Cu(NCS)2(INH)2.5H2O (I2) and Cu(NCO)2(INH)2.4H2O (I3) was evaluated by the Comet, Micronucleus-cytome and Salmonella microsome (Ames test) assays. The cell viability using resazurin assay indicated that I1, I2 e I3 had moderate to low capacity to reduce the viability of colorectal cells (Caco-2), liver cells (HepG2), lung cells (GM 07492-A and A549) and endothelial cells (HU-VE-C). On genotoxicity/mutagenicity, I1 complex did not induce sizable levels of DNA damage in HepG2 cells (Comet assay), and gene (Ames test) and chromosomal (Micronucleus-cytome assay) mutations. Already, I2 and I3 complexes were considered mutagenic in the highest concentrations used. In light of the above, these results contribute to valuable data on the safe use of Cu(II) complexes. Considering the absence of mutagenicity and cytotoxicity of I1, this complex is a potential candidate for the development of a new drug to the treatment tuberculosis, while I2 and I3 require caution in its use.

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.

Antibacterial, Preservative, and Mutagenic Potential of Copaifera spp. Oleoresins Against Causative Agents of Foodborne Diseases.

Foodborne diseases (FBDs) are a serious public health concern worldwide. In this scenario, preservatives based on natural products, especially plants, have attracted researchers' attention because they offer potential antimicrobial action as well as reduced health impact. The genus Copaifera spp., which is native of tropical South America and West Africa, contains several species for which pharmacological activities, including antibacterial effects, have been described. On the basis of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antibiofilm activity (inhibition and eradication), preservative capacity, and Ames test, we evaluated the antibacterial, preservative, and mutagenic potential of Copaifera spp. oleoresins against the causative agents of FBDs. The Copaifera duckei, Copaifera reticulata, Copaifera paupera, and Copaifera pubiflora oleoresins displayed promising MIC/MBC values-from 12.5 to 100 µg/mL-against Staphylococcus aureus (American Type Culture Collection [ATCC] 29213), Listeria monocytogenes (ATCC 15313), and Bacillus cereus (ATCC 14579). C. duckei, C. reticulata, C. paupera, and C. pubiflora oleoresin concentrations ranging from 25 to 200 µg/mL and from 100 to 400 µg/mL inhibited biofilm formation and eradicated biofilms, respectively. The oleoresins did not exert mutagenic effects and had superior food preservative action to sodium benzoate (positive control). In conclusion, Copaifera oleoresins exhibit potential antibacterial activity and are not mutagenic, which makes them a promising source to develop novel natural food preservatives to inhibit foodborne pathogens.

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.

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.

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.

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.

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 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.

Self-Supported Biopolymeric Films Based on Onion Bulb (Allium cepa L.): Gamma-Radiation Effects in Sterilizing Doses.

Sterilization is a fundamental step to eliminate microorganisms prior to the application of products, especially in the food and medical industries. γ-irradiation is one of the most recommended and effective methods used for sterilization, but its effect on the properties and performance of bio-based polymers is negligible. This work is aimed at evaluating the influence of γ-radiation at doses of 5, 10, 15, 25, 30, and 40 kGy on the morphology, properties, and performance of bioplastic produced from onion bulb (Allium cepa L.), using two hydrothermal synthesis procedures. These procedures differ in whether the product is washed or not after bioplastic synthesis, and are referred to as the unwashed hydrothermally treated pulp (HTP) and washed hydrothermally treated pulp (W-HTP). The morphological analysis indicated that the film surfaces became progressively rougher and more irregular for doses above 25 kGy, which increases their hydrophobicity, especially for the W-HTP samples. In addition, the FTIR and XRD results indicated that irradiation changed the structural and chemical groups of the samples. There was an increase in the crystallinity index and a predominance of the interaction of radiation with the hydroxyl groups-more susceptible to the oxidative effect-besides the cleavage of chemical bonds depending on the γ-radiation dose. The presence of soluble carbohydrates influenced the mechanical behavior of the samples, in which HTP is more ductile than W-HTP, but γ-radiation did not cause a change in mechanical properties proportionally to the dose. For W-HTP, films there was no mutagenicity or cytotoxicity-even after γ-irradiation at higher doses. In conclusion, the properties of onion-based films varied significantly with the γ-radiation dose. The films were also affected differently by radiation, depending on their chemical composition and the change induced by washing, which influences their use in food packaging or biomedical devices.

Mutagenicity and antimutagenicity of (-)-hinokinin a trypanosomicidal compound measured by Salmonella microsome and comet assays.

BACKGROUND: The dibenzylbutyrolactone lignan (-)-hinokinin (HK) was derived by partial synthesis from (-)-cubebin, isolated from the dry seeds of the pepper, Piper cubeba. Considering the good trypanosomicidal activity of HK and recalling 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 (anti) mutagenic∕ genotoxic activities of HK. METHODS: The mutagenic∕ genotoxic activities were evaluated by the Ames test on Salmonella typhimurium strains TA98, TA97a, TA100 and TA102, and the comet assay, so as to assess the safe use of HK in the treatment of Chagas' disease. The antimutagenic ∕antigenotoxic potential of HK were also tested against the mutagenicity of a variety of direct and indirect acting mutagens, such as 4- nitro-o-phenylenediamine (NOPD), sodium azide (SA), mitomycin C (MMC), benzo[a]pyrene (B[a]P), aflatoxin B1 (AFB1), 2-aminoanthracene (2-AA) and 2-aminofluorene (2-AF), by the Ames test, and doxorubicin (DXR) by the comet assay. RESULTS: The mutagenicity∕genotoxicity tests showed that HK did not induce any increase in the number of revertants or extent of DNA damage, demonstrating the absence of mutagenic and genotoxic activities. On the other hand, the results on the antimutagenic potential of HK showed a strong inhibitory effect against some direct and indirect-acting mutagens. CONCLUSIONS: Regarding the use of HK as an antichagasic drug, the absence of mutagenic effects in animal cell and bacterial systems is encouraging. In addition, HK may be a new potential antigenotoxic ∕ antimutagenic agent from natural sources. However, the protective activity of HK is not general and varies with the type of DNA damage-inducing agent used.

Mutagenicity of flavonoids assayed by bacterial reverse mutation (Ames) test.

The mutagenicity of ten flavonoids was assayed by the Ames test, in Salmonella typhimurium strains TA98, TA100 and TA102, with the aim of establishing hydroxylation pattern-mutagenicity relationship profiles. The compounds assessed were: quercetin, kaempferol, luteolin, fisetin, chrysin, galangin, flavone, 3-hydroxyflavone, 5-hydroxyflavone and 7-hydroxyflavone. In the Ames assay, quercetin acted directly and its mutagenicity increased with metabolic activation. In the presence of S9 mix, kaempferol and galangin were mutagenic in the TA98 strain and kaempferol showed signs of mutagenicity in the other strains. The absence of hydroxyl groups, as in flavone, only signs of mutagenicity were shown in strain TA102, after metabolization and, among monohydroxylated flavones (3-hydroxyflavone, 5-hydroxyflavone and 7-hydroxyflavone), the presence of hydroxyl groups only resulted in minor changes. Luteolin and fisetin also showed signs of mutagenicity in strain TA102. Finally, chrysin, which has only two hydroxy groups, at the 5-OH and 7-OH positions, also did not induce mutagenic activity in any of the bacterial strains used, under either activation condition. All the flavonoids were tested at concentrations varying from 2.6 to 30.7 nmol/plate for galangin and 12.1 to 225.0 nmol/plate for other flavonoids. In light of the above, it is necessary to clarify the conditions and the mechanisms that mediate the biological effects of flavonoids before treating them as therapeutical agents, since some compounds can be biotransformed into more genotoxic products; as is the case for galangin, kaempferol and quercetin.

Comparative Studies of the (Anti) Mutagenicity of Baccharis dracunculifolia and Artepillin C by the Bacterial Reverse Mutation Test.

Baccharis dracunculifolia is a plant native from Brazil, commonly known as 'Alecrim-do-campo' and 'Vassoura' and used in alternative medicine for the treatment of inflammation, hepatic disorders and stomach ulcers. Previous studies reported that artepillin C (ArtC, 3-{4-hydroxy-3,5-di(3-methyl-2-butenyl)phenyl}-2(E)-propenoic acid), is the main compound of interest in the leaves. This study was undertaken to assess the mutagenic effect of the ethyl acetate extract of B. dracunculifolia leaves (Bd-EAE: 11.4-182.8 µg/plate) and ArtC (0.69-10.99 µg/plate) by the Ames test using Salmonella typhimurium strains TA98, TA97a, TA100 and TA102, and to compare the protective effects of Bd-EAE and ArtC against the mutagenicity of a variety of direct and indirect acting mutagens such as 4-nitro-O-phenylenediamine, sodium azide, mitomycin C, benzo[a]pyrene, aflatoxin B1, 2-aminoanthracene and 2-aminofluorene.The mutagenicity test showed that Bd-EAE and ArtC did not induce an increase in the number of revertant colonies indicating absence of mutagenic activity. ArtC showed a similar antimutagenic effect to that of Bd-EAE in some strains of S. typhimurium, demonstrating that the antimutagenic activity of Bd-EAE can be partially attributed to ArtC. The present results showed that the protective effect of whole plant extracts is due to the combined and synergistic effects of a complex mixture of phytochemicals, the total activity of which may result in health benefits.

Evaluation of cytotoxicity and genotoxicity of a novel oxovanadium complex with orotate.

The development of new drugs based on metal complexes requires a detailed analysis of their biological endpoints. In this study, we report the genotoxic profile and influence on cell proliferation and death of the oxovanadium(IV) complex with orotic acid ([VO(C5H4N2O4)2], VO(oro)). Human hepatocellular carcinoma cells (HepG2) were the most sensitive tumor cells to VO(oro), which interfered with the integrity of cell membranes and proliferative capacity in a dose-dependent manner, inducing cell death by apoptosis. Regarding genotoxicity, VO(oro) did not induce considerable levels of DNA damage in HepG2 cells (comet test) and gene mutations (Ames test). However, it caused a statistically significant increase in the frequency of micronuclei at the highest concentration tested (12.5 µmol.L-1), indicating aneuploidy and clastogenicity. The data presented here provide information on various biological aspects of the VO(oro) complex, which may allow the elucidation of its mechanism of action as a possible therapeutic agent.

Novel Ru(II)-bipyridine/phenanthroline-lapachol complexes as potential anti-cancer agents.

For the first time, we herein report on the syntheses of two new Ru(II)/bipyridine/phenanthroline complexes containing lapachol as ligand: complex (1), [Ru (bipy)2(Lap)]PF6 and complex (2), [Ru(Lap)(phen)2]PF6, where bipy = 2,2'-bipyridine and ph en = 1,10-phenanthroline; Lap = lapachol (2-hydroxy-3-(3-methylbut-2-en-1- yl)naphthalene-1,4-dione). The complexes were synthesized and characterized by elemental analyses, molar conductivity, mass spectrometry, ultraviolet-visible and infrared spectroscopies, nuclear magnetic resonance (1H, 13C), and single crystal X-ray diffraction, for complex (2). In addition, in vitro cytotoxicity was tested against six cancer cells: A549 (lung carcinoma); DU-145 (human prostate carcinoma); HepG2 (human hepatocellular carcinoma), PC-3 (human prostate adenocarcinoma); MDA-MB-231 (human breast adenocarcinoma); Caco-2 (human colorectal adenocarcinoma), and against two non-cancer cells, FGH (human gingival normal fibroblasts) and PNT-2 (prostate epithelial cells). Complex (1) was slightly more toxic and selective than complex (2) for all cell lines, except against the A549 cells, where (2) was more potent than complex (1). The complexes induced an increase in the reactive oxygen species, and the co-treatment with N-acetyl-L-cysteine remarkably suppressed the ROS generation and prevented the reduction of cell viability, suggesting that the cytotoxicity of the complexes is related to the ROS-mediated pathway. Further studies indicated that the complexes may bind to DNA via minor groove interaction. Our studies also revealed that free Lap induces gene mutations in Salmonella Typhimurium, nevertheless, the complexes demonstrated the absence of genotoxicity by the Ames test. The present study provides a relevant contribution to understanding the anti-cancer potential and genetic toxicological events of new ruthenium complexes containing the lapachol molecule as a ligand.

Effect of the dibenzylbutyrolactone lignan (-)-hinokinin on doxorubicin and methyl methanesulfonate clastogenicity in V79 Chinese hamster lung fibroblasts.

The dibenzylbutyrolactone lignan (-)-hinokinin (HK) was obtained by partial synthesis from (-)-cubebin, isolated from the dry seeds of the pepper, Piper cubeba. In view of the trypanocidal activity of HK and its potential as a lead compound for drug development, evaluation of its possible genotoxic activity is required. We have tested HK for possible genotoxicity and evaluated the compound's effect on the activity of the clastogens doxorubicin (DXR) and methyl methanesulfonate (MMS) in the micronucleus (MN) assay with Chinese hamster lung fibroblast V79 cells. HK alone did not induce MN, at concentrations up to 128microM. In combined treatments, HK reduced the frequency of MN induced by MMS. With respect to DXR, HK exerted a protective effect at lower concentrations, but at higher concentrations it potentiated DXR clastogenicity.