Water assessment of the Itapemirim River/Espírito Santo (Brazil): abiotic and toxicogenetic aspects.

The Itapemirim River is considered one of the most important water resources in the state of Espírito Santo, Brazil. However, environmental problems due to continuous anthropogenic contamination are threatening its potential use. This study assessed water quality by analyzing abiotic and toxicogenetic aspects of the water from four stations along the river. Samples were collected in both dry and rainy seasons. Most of the abiotic variables were below the threshold established by CONAMA Resolution No. 357/2005, and so were most of the metals. However, Al and Cu contents were above those allowed by legislation, ranging from 0.2 to 0.9 mg/L. Regarding toxicogenetic aspects, genotoxic effects were observed in meristematic cells of Allium cepa, in micronucleus test and comet assay of Oreochromis niloticus, and CHO-K1 cells. Mutagenic effects were significant at RI 02 (0.34), RI 03 (0.46), and RI 04 (0.12) stations on the first campaign in A. cepa F1 cells, compared to the negative control (0.0). The second campaign revealed the same results, but with the addition of samples from RI 01 (0.17) and RI 03 (0.18) showing mutagenicity in the micronucleus test with fish erythrocytes when compared to the negative control (0.3). Essentially, all the samples evaluated in both campaigns showed damage in A. cepa, O. niloticus, and CHO-K1 cells, thus demonstrating that the water quality of the Itapemirim River is compromised and requires action plans for its recovery.

In vivo antimutagenic and antiatherogenic effects of the (1 → 3)(1 → 6)-ß-d- glucan botryosphaeran.

The antimutagenic effect of botryosphaeran, an exocellular (1 → 3)(1 → 6)-ß-d-glucan, from the ascomyceteous and plant-borne endophytic fungus, Botryosphaeria rhodina MAMB-05, was evaluated in young (6-8 weeks) and elderly (18 months) Swiss albino mice of both genders. The hypolipidemic, hypoglycemic and antiatherogenic potential was also evaluated in 18-month old male LDL receptor knockout (LDLr-/-) mice. Administration of botryosphaeran by gavage (doses: 7.5, 15, 30 mg/kg b.w./day) in a 30-day pretreatment protocol (young mice), or 15-day protocol (older mice), did not cause genotoxicity as assessed by the micronucleus test in peripheral blood (PB) and bone marrow cells (BMCs). Furthermore, there was no cytotoxic effect of this ß-d-glucan in the treatments. A lower frequency of micronuclei was observed in BMCs from young and old mice that received botryosphaeran, indicating its antimutagenic effect. Botryosphaeran (30 mg/kg b.w./day) promoted 102.22% (young) and 103.45% (elderly) reductions in cyclophosphamide-induced damage in male mice. Botryosphaeran also exerted chemoprotective effects in LDLr-/- and wild-type (C57BL/6) mice. Botryosphaeran treatment for 15 days at a dose of 30 mg/kg b.w./day improved the lipidic profile (reductions of 53.8-84.3%), and decreased aortic lipid deposition (32.8%) in the LDLr-/- atherosclerotic mice. The results indicate botryosphaeran has relevant biologic effects, making it a promising candidate for the development of new therapeutic agents.

In vitro protective effects of botryosphaeran, a (1→3;1→6)-ß-d-glucan, against mutagens in normal and tumor rodent cells.

Botryosphaeran (BOT) is an exocellular ß-d-glucan (carbohydrate biopolymer) of the (1→3;1→6)-linked type produced by Botryosphaeria rhodina MAMB-05. The cytotoxic, mutagenic, genotoxic, and protective effects of this substance were evaluated in Chinese hamster lung fibroblasts (V79) and rat hepatocarcinoma cells (HTC) by the micronucleus test (MN) and the comet assay. BOT was not genotoxic in either cell line; it decreased the clastogenic effects of doxorubicin, H2O2, and benzo[a]pyrene. These results indicate that BOT may have potential as a therapeutic agent.

Modulation of gene expression and cell cycle by botryosphaeran, a (1→3)(1→6)-ß-d-glucan in human lymphocytes.

There is growing interest in the anticancer and immunomodulatory potential of fungal ß-d-glucans. In the present study, the modulation of gene expression via RT-qPCR and cell cycle kinetics via flow cytometry were assessed in human normal and tumor (Jurkat) lymphocytes after treatment with botryosphaeran (a fungal (1→3)(1→6)-ß-d-glucan) from Botryosphaeria rhodina MAMB-05. Cell cultures were treated with botryosphaeran either alone, or in combination with doxorubicin (DXR), in a post-treatment protocol. The expression of genes involved in immunomodulatory processes, apoptosis and cell cycle control, as well as ß-d-glucans cell receptors were assessed. Flow cytometry analysis identified tetraploid Jurkat cells in G1 phase when treated with botryosphaeran combined with DXR. This antiproliferative effect in G1 may be associated with down-regulation of the expression of genes involved in the G1 checkpoint. The repression of the CCR5 gene following botryosphaeran treatment, either alone or in combination with DXR, in tumor lymphocytes indicates a possible affinity of this particular (1→3)(1→6)-ß-d-glucan for the receptor CCR5. Therefore, botryosphaeran action appears to be involved in the repression of genes related to the G1 phase of the cell cycle and possibly in the interaction of the botryosphaeran, either alone, or in combination with DXR, with the CCR5 receptor.

Determination of the antimutagenicity of an aqueous extract of Rhizophora mangle L. (Rhizophoraceae), using in vivo and in vitro test systems.

An aqueous extract of Rhizophora mangle L. bark is used as raw material in pottery making in the State of Espirito Santo, Brazil. This extract presents large quantities of tannins, compounds possessing antioxidant properties. Tannin antioxidant activity, as a plant chemical defense mechanism in the process of stabilizing free radicals, has been an incentive to studies on anti-mutagenicity. The present work aimed to evaluate possible antimutagenic activity of a R. mangle aqueous extract, using the Allium cepa test-system and micronuclear (MN) assay with blockage of cytokinesis in Chinese hamster ovary cells (CHO-K1). The Allium cepa test-system indicated antimutagenic activity against the damage induced by the mutagenic agent methyl methanesulfonate. A reduction in both MN cell frequency and chromosome breaks occurred in both the pre and post-treatment protocols. The MN testing of CHO-K1 cells revealed anti-mutagenic activity of the R. mangle extract against methyl methanesulfonate and doxorubicin in pre, simultaneous and post-treatment protocols. These results suggest the presence of phyto-constituents in the extract presenting demutagenic and bio-antimutagenic activities. Since the chemical constitution of Rhizophora mangle species presents elevated tannin content, it is highly probable that these compounds are the antimutagenic promoters themselves.

Determination of the antimutagenicity of an aqueous extract of Rhizophora mangle L. (Rhizophoraceae), using in vivo and in vitro test systems

An aqueous extract of Rhizophora mangle L. bark is used as raw material in pottery making in the State of Espirito Santo, Brazil. This extract presents large quantities of tannins, compounds possessing antioxidant properties. Tannin antioxidant activity, as a plant chemical defense mechanism in the process of stabilizing free radicals, has been an incentive to studies on anti-mutagenicity. The present work aimed to evaluate possible antimutagenic activity of a R. mangle aqueous extract, using the Allium cepa test-system and micronuclear (MN) assay with blockage of cytokinesis in Chinese hamster ovary cells (CHO-K1). The Allium cepa test-system indicated antimutagenic activity against the damage induced by the mutagenic agent methyl methanesulfonate. A reduction in both MN cell frequency and chromosome breaks occurred in both the pre and post-treatment protocols. The MN testing of CHO-K1 cells revealed anti-mutagenic activity of the R. mangle extract against methyl methanesulfonate and doxorubicin in pre, simultaneous and post-treatment protocols. These results suggest the presence of phyto-constituents in the extract presenting demutagenic and bio-antimutagenic activities. Since the chemical constitution of Rhizophora mangle species presents elevated tannin content, it is highly probable that these compounds are the antimutagenic promoters themselves.