Evaluation of the antigenotoxic and antioxidant activity induced by Croton antisyphiliticus.

This study aimed to investigate antigenotoxicity and antioxidant potential of extract, fractions and vitexin from C. antisyphiliticus. Methanolic extract was fractionated through solvents of increasing polarity. The composition of extracts and fractions were evaluated through phytochemical screening. Micronucleus test was performed in mice to evaluate the antigenotoxicity. Antioxidant activity was measured using the assay 1,1-diphenyl-2-picrylhydrazyl (DPPH), iron ion chelating, thiobarbituric acid assay and nitric oxide scavenging. Treatment with extract, fractions and vitexin did not produce an increase in Micronucleus mean values. However, Micronucleus (MN) mean values decreased in relation to control. methanolic extract presented antioxidant potential for DPPH (81%), iron ion chelating (77.8%), Thiobarbituric Acid (TBARS) (32.49%) and Nitric Oxide (NO) (80.97%). Ethyl acetate fraction showed the highest antioxidant activity (65.46%). The vitexin showed a Inhibitory Concentration (IC50) of DPPH value smaller in relation to control. Vitexin flavonoid was detected by High Performance Liquid Chromatography (HPLC), infrared spectrometry and nuclear magnetic resonance. It can be inferred that methanolic extract, fraction ethyl acetate and vitexin isolated from C. antisyphiliticus is endowed with antigenotoxic and antioxidant potential.

In vitro anthelmintic activity of Psidium guajava hydroalcoholic extract against gastro-intestinal sheep nematodes.

Tanniferous plants have been used for ruminants verminosis control and represent a possibility to minimize the pharmacological resistance against conventional antiparasitics. This study aimed to evaluate the antihelminthic activity of the hydroalcoholic extract of stem bark of guava tree (PgHA). It was performed the hatchability and larval migration inhibition assays to evaluate PgHA at the following concentrations 0.62, 1.25, 2.5 and 5.0 mg mL-1 and the control treatments. The total polyphenol, flavonoid and tannin contents were determined by phytochemical analysis, high performance liquid chromatography coupled to mass spectrometry. The antioxidant activity was evaluated by 1,1-diphenyl-2-picrylhydrazyl, ferric reducing antioxidant power and thiobarbituric acid reactive substances tests. It was also determinated total protein, intracellular H2O2 and antioxidant activity of enzimes: glutathione S-transferase and superoxide dismutase. PgHA was able to inhibit both hatchability and larval migration, but only hatchability inhibition presented dose-dependent pattern. The antioxidant activity was demonstrated by linear regression with IC50 corresponding to 534.02 µg mL-1. The antiparasitic mechanism occurred through pro-oxidative activity by the increase of total proteins, intracellular H2O2 and the lipid peroxidation products, as well as the increase of the enzymes above related. Thus, the PgHA showed antiparasitic activity in vitro.

Genotoxicity, anti-melanoma and antioxidant activities of Hymenaea courbaril L. seed extract.

Hymenaea courbaril has been used to treat different diseases, although its properties are yet to be scientifically validated. The objective of this study was to determine the cytotoxicity, genotoxicity, antigenotoxicity and antioxidant potentials of hydroethanolic extract from H. courbaril seeds. Therefore, for the cytotoxicity test an anti-melanoma assay was performed in B16F10 strain cells. The genotoxicity and antigenotoxicity was evaluated in bone marrow cells (Permit number: 002/2010) of mice, the antioxidant activity was determined by the DPPH test and the total flavonoid content was also determined. The hydroethanolic extract showed antigenotoxic effect and antioxidant activity. It was verified that total flavonoid content was 442.25±18.03 mg RE/g dry extract. HPLC-PAD chromatogram revealed presence of flavones as majority compound in evaluated extract. The results allowed us to also infer that the hydroethanolic extract from seeds shows cytotoxic activity against B16F10 melanoma cells line and it has dose-and-time-dependency.

Modulatory effects of Tabebuia impetiginosa (Lamiales, Bignoniaceae) on doxorubicin-induced somatic mutation and recombination in Drosophila melanogaster

The wing Somatic Mutation and Recombination Test (SMART) in D. melanogaster was used to study genotoxicity of the medicinal plant Tabebuia impetiginosa. Lapachol (naphthoquinone) and β-lapachone (quinone) are the two main chemical constituents of T. impetiginosa. These compounds have several biological properties. They induce apoptosis by generating oxygen-reactive species, thereby inhibiting topoisomerases (I and II) or inducing other enzymes dependent on NAD(P)H:quinone oxidoreductase 1, thus affecting cell cycle checkpoints. The SMART was used in the standard (ST) version, which has normal levels of cytochrome P450 (CYP) enzymes, to check the direct action of this compound, and in the high bioactivation (HB) version, which has a high constitutive level of CYP enzymes, to check for indirect action in three different T. impetiginosa concentrations (10 percent, 20 percent or 40 percent w/w). It was observed that T. impetiginosa alone did not modify the spontaneous frequencies of mutant spots in either cross. The negative results observed prompted us to study this phytotherapeuticum in association with the reference mutagen doxorubicin (DXR). In co-treated series, T. impetiginosa was toxic in both crosses at higher concentration, whereas in the HB cross, it induced a considerable potentiating effect (from ~24.0 to ~95.0 percent) on DXR genotoxity. Therefore, further research is needed to determine the possible risks associated with the exposure of living organisms to this complex mixture.