Andiroba oil and nanoemulsion (Carapa guianensis Aublet) reduce lesion severity caused by the antineoplastic agent doxorubicin in mice.

Doxorubicin (DOX) is an anthracycline antibiotic used in the fight against many types of cancer. Although it is quite effective for this purpose, its clinical use is limited by its severe side effects, highlighting the relevance of efforts to identify substances that act to minimize these effects. In this work, we sought to verify the ability of andiroba oil (AO) and a nanoemulsion of andiroba oil (AN) to lessen the side effects of DOX. The animals were separated into 7 groups with 6 animals each: mice treated with AO (2000 mg/kg), AN (2000 mg/kg), the antineoplastic agent DOX (40 mg/kg), AO+DOX, AN+DOX and solvent controls was used of negative control (corn oil and nanoemulsion surfactant). AO and AN were administered for 14 consecutive days orally by gavage and on the 13th day, applied DOX by intraperitoneal route (i.p.), in order to evaluate the protective potential of andiroba. The animals were euthanized on the 15th day. Hematological, biochemical, histological, and immunohistochemical parameters were analyzed. Andiroba reduced several aspects of the severity of lesions caused by DOX, decreasing hematotoxicity and the severity of histological changes in the liver and kidneys, and reducing the frequency of apoptotic cell death. In many cases, AN showed greater efficacy than AO alone, reflecting the feasibility of using this nanotechnology to improve the pharmacokinetics of lipid compounds in the body. The study sheds new light on the therapeutic benefits of andiroba and suggests new ways for investigating how the quantity and quality of lipid compounds affect exposed organisms.

Lethal and sublethal exposure of Hemichromis bimaculatus (Gill, 1862) to malachite green and possible implications for ornamental fish.

Malachite green (MG) is a triphenylmethane dye that is widely used in aquaculture as a fungicide, bactericide, ectoparasiticide, and antiprotozoal. There is great debate regarding the potential for this compound to trigger adverse effects. Here, we review the previous findings and then evaluate the lethal and sublethal effects of MG in the species Hemichromis bimaculatus (jewelfish). The lethal concentration for 50% of the fish in 96 h was 1 mg/L. We observed a dose-dependent increase in the percentage of fish mortality as well as physical and behavioral changes. We further found that the highest tested sublethal dose significantly increased the DNA damage index identified using the comet assay (74.97 ± 13.8 at a significant level of P < 0.05 for the 0.75 mg/L concentration), but did not significantly alter the results of the micronucleus test. Although our results suggest that MG confers risks on exposed fish, the findings were significant only at the highest exposure concentration (0.75 mg/L). At lower concentrations (0.25 mg/L and 0.5 mg/L), no adverse effect was observed. The maximum MG concentration recommended for use in ornamental fish farming is 0.2 mg/L. Therefore, our results suggest that, specifically for the parameters analyzed in this work, MG does not have any adverse effect when users strictly adhere to the recommended concentration criteria for ornamental fish.

Aqueous ethanol extract of Libidibia ferrea (Mart. Ex Tul) L.P. Queiroz (juca) exhibits antioxidant and migration-inhibiting activity in human gastric adenocarcinoma (ACP02) cells.

Libidibia ferrea (juca) is a plant belonging to the Fabaceae (Leguminosae) family, whose antioxidant activity has been widely described in the literature. We evaluated this parameter of Aqueous ethanol extract (AE), ethyl acetate (ACO), chloroform (CLO) and hexane (HEX) extracts of L. ferrea. We then tested the most active extract for its toxicity and ability to inhibit migratory activity in the ACP02 gastric adenocarcinoma cell line in vitro. The AE and ACO extracts both had antioxidant activity, the AE extract showing greater potential. This may reflect that both extracts contained phenolic compounds. Although AE extract showed no cytotoxic, mutagenic or genotoxic effect, it altered cell morphology and migration activity. Analysis of apoptosis/necrosis indicated that this parameter does not appear to account for the apparent ability of AE to inhibit cancer cell migration. We speculate that the morphological changes in AE-treated cells could be due to cytoskeleton alterations related to the presence of myo-inositol in AE extract. Together, our results demonstrate this extract of L. ferrea can act as an exogenous antioxidant and might prove useful in efforts to fight secondary tumors.

Short-term exposure to low doses of rotenone induces developmental, biochemical, behavioral, and histological changes in fish.

Rotenone, a natural compound derived from plants of the genera Derris and Lonchocarpus, is used worldwide as a pesticide and piscicide. This study aims to assess short-term toxicity of rotenone to early-life stages of the fish Danio rerio and Poecilia reticulata using a wide and integrative range of biomarkers (developmental, biochemical, behavioral, and histopathological). Moreover, the species sensitivity distribution (SSD) approach was used to compare rotenone acute toxicity to fish species. Toxicity tests were based on the OECD protocols, fish embryo toxicity test (for D. rerio embryos), and fish acute toxicity test (for P. reticulata juveniles). D. rerio embryos were used to estimate lethal concentrations and analyze embryonic and enzymatic alterations (activity of catalase, glutathione-S-transferase, and cholinesterase), while P. reticulata juveniles were used for the assessment of histological damage in the gills and liver. Rotenone induced significant mortality in zebrafish embryos with a 96-h lethal concentration 50% (LC50) = 12.2 µg/L. Rotenone was embryotoxic, affecting the development of D. rerio embryos, which showed cardiac edema; tail deformities; loss of equilibrium; and a general delay characterized by lack of tail detachment, delayed somite formation, yolk sac absorption, and lack of pigmentation. Biochemical biomarker inhibition was observed for concentrations ≥1 µg/L for CAT and glutathione-S-transferase (GST) and for cholinesterase (ChE) in concentration from 10 µg/L. Behavioral changes were observed for P. reticulata juveniles exposed to concentrations equal to or above 25 µg/L of rotenone; moreover, histological damage in the liver and gills of fish exposed to concentrations equal to or above 2.5 µg/L could be observed. A hazard concentration 5% (HC5) of 3.2 µg/L was estimated considering the acute toxicity data for different fish species (n = 49). Lethal and sublethal effects of rotenone raise a concern about its effects on nontarget fish species, especially because rotenone and its metabolite rotenolone are frequently reported in the microgram range in natural environments for several days after field applications. Rotenone should be used with caution. Given the high toxicity and wide range of sublethal effects here reported, further studies in a chronic exposure scenario are recommended.

Profile of micronucleus frequencies and nuclear abnormalities in different species of electric fishes (Gymnotiformes) from the Eastern Amazon.

The frequency of spontaneous micronucleus (MN) formation in fish species needs to be determined to evaluate their usefulness for genotoxic biomonitoring. The definition of a good bioindicator takes into account the current knowledge of its metabolic traits as well as other factors including its feeding behavior and relationship to the environment. In this study, we compared the basal frequencies of micronucleated erythrocytes and nuclear abnormalities (NA) among different species of the fish Order Gymnotiformes (Rhamphichthys marmoratus, Steatogenys elegans, Sternopygus macrurus, Parapteronotus hasemani, Gymnotus mamiraua, Gymnotus arapaima, Brachyhypopomus beebei, Brachyhypopomus n. sp. BENN) sampled in several localities of the Eastern Amazon. A baseline of MN and NA frequency in these fish was determined, enabling the identification of potentially useful species as models for genotoxicity studies. Only one impacted sample collected at a site in the River Caripetuba showed a significant number of NAs, which may be due to the release of wastewater by neighbouring mining industries and by the burnt fuel released by the small boats used by a local community. Our results may provide support for further studies in areas of the Eastern Amazon affected by mining, deforestation and other anthropogenic activities.