Search

The present study evaluated the ecological risk of metal contamination in sediments of Guanabara Bay (GB) by combining multiple lines of evidence (LOEs). Chemical analysis and a set of whole-sediment toxicity assays were conducted with Tiburonella viscana, Kalliapseudes schubartii, Anomalocardia flexuosa, and Nitocra sp. Results were integrated by multivariate analysis and qualitative methods. Additionally, a whole-sediment Toxicity Identification Evaluation technique (TIE) was applied to identify the chemical groups responsible for the effects. Sediments from harbor and industrial areas exhibited toxicity linked to moderate to high concentrations of Zn, Pb, Cu and Cr. The TIE technique confirmed such effects, but it also indicates the contribution of ammonia and organic compounds to the observed toxicity. Our results demonstrate that the combination of multiple LOEs improves the effectiveness of environmental risk assessment of chemical stressors and management of coastal ecosystems in tropical regions., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Ethnopharmacological Relevance: Copaifera malmei Harms (Fabaceae) is a plant that occurs in the central region of Brazil, where the plant's leaves infusion is popularly used to treat gastric ulcer and inflammatory diseases. This study was aimed to investigate the gastroprotective activity and mode of action of the plants' leaves infusion in order to establish the scientific basis for such usage, and to assess its potential as a source of an anti-ulcer agent., Materials and Methods: Leaves infusion extract of the plant (SIECm) was prepared, freeze dried and lyophilised. Its qualitative and quantitative phytochemical constituents were investigated using TLC and HPLC techniques. The safety profile was evaluated on CHO-k1 epithelial cells viability using the Alamar blue assay, and by acute toxicity test in mice. The gastroprotection and anti-ulcer efficacy of the SIECm (25, 100 and 400mg/kg, p.o.) were tested using acute (acidified ethanol, piroxicam and water restrain stress), and chronic (acetic acid) experimental ulcer models. The plausible mode of action of the SIECm was assessed using gastric secretion, gastric barrier mucus, nitric oxide, and its antioxidant (myeloperoxidase and catalase) effects in mice and rats. The histopathological analyses of the ulcerated tissues as well as the extract's activity on Helicobacter pylori were also investigated., Results: Phytochemical tests indicated the presence of mainly phytosterols, phenolics and flavonoids. The SIECm exhibited no cytotoxic effects on the CHO-k1 cells, and no oral acute toxicity in mice. It prevented against the acute induced ulcerations by enhancing gastroprotection through gastric mucus production, NO modulation, antioxidant, reduced gastric secretion and enhanced chronic ulcers healing process, as shown by reduction/prevention of epithelial and vascular damage, in addition to reduction in leucocyte infiltration. The SIECm however did not exhibit activity against H. pylori., Conclusion: The SIECm is safe, contain useful phytochemicals and exhibited significant gastroprotective/anti-ulcer effects. The results justify its folkloric usage, and provided scientific evidence of its potential as a source of new phytodrug to treat gastric ulcers., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Ethnopharmacological Relevance: Leonotis nepetifolia (L) R. Br., Lamiaceae, a pantropical shrub, popularly known in Brazil as "cordão-de-frade", "rubim", is reportedly used in Brazilian ethnomedicine as well as in different countries in the treatments of ailments such as infections, inflammations, wounds, stomach disorders, among others., Aim of the Study: To evaluate its potential cytotoxicity and antibacterial mode of action of the hydroethanolic extract of L. nepetifolia (HELn) leaves, including phytochemical analysis., Materials and Methods: The cytotoxicity of HELn was investigated by Alamar blue assay, using CHO-K1 cells. Antibacterial activity of HELn was tested by broth microdilution methods against a panel of bacteria of clinical interest. The mode of action of L. nepetifolia was studied by targeting bacterial membranes. Phytochemical analysis was performed by determining total secondary metabolites with spectrophotometric assays and HPLC., Results: HELn is not cytotoxic in the in vitro evaluation (IC50>200 μg/mL). It demonstrated a good spectrum of antibacterial activity with major activity against Shigella flexneri, Enterococcus faecalis, Staphylococcus aureus and Bacillus subtilis with MIC=6.25 µg/mL, Helicobacter pylori with MIC of 25 µg/mL and Streptococcus pyogenes with MIC of 50 µg/mL. Its mode of action is associated, at least partly, with changes in the permeability of bacterial membranes, as evidenced by the increased entry of hydrophobic antibiotics in Shigella flexneri and intense efflux of K(+) and nucleotide leakage in E. faecalis and Shigella flexneri. In addition, the presence of phenols, flavonoids and carotenoids, described in the literature to possess antibacterial effects, were detected in the composition of HELn, with high phenol content (11.55%), especially the flavonoids (6.47%)., Conclusion: The results indicate that HELn has low cytotoxicity and potent antibacterial activity. It is bacteriostatic in nature, possibly acting at the level of bacterial membranes, especially on the cytoplasmic membrane and outer membrane, thus supporting its popular use in infectious processes. In addition, the presence of phenols, flavonoids, carotenoids, fatty acids and steroids, described in the literature as possessing antimicrobial activity, were detected in the composition of HELn., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)