Inhibitory effects of benzimidazole containing new phenolic Mannich bases on human carbonic anhydrase isoforms hCA I and II.

New phenolic mono and bis Mannich bases incorporating benzimidazole, such as 2-(aminomethyl)-4-(1H-benzimidazol-2-yl)phenol and 2,6-bis(aminomethyl)-4-(1H-benzimidazol-2-yl)phenol were synthesized starting from 4-(1H-benzimidazol-2-yl)phenol. Amines used for the synthesis included dimethylamine, pyrrolidine, piperidine, N-methylpiperazine and morpholine. The CA inhibitory properties of these compounds were tested on the human carbonic anhydrase (CA, EC 4.2.1.1) isoforms hCA I and hCA II. These new compounds, as many phenols show moderate CA inhibitory properties.

Embryotoxicity of nitrophenols to the early life stages of zebrafish (Danio rerio).

The nitrophenols (NPs) are water-soluble compounds. These compounds pose a significant health threat since they are priority environmental pollutants. In this study, 2-Nitrophenol (2NP) and 2,4-dinitrophenol (DNP) were examined for embryo and early life stage toxicity in zebrafish (Danio rerio). Acute toxicity and teratogenicity of 2NP and DNP were tested for 4 days using zebrafish embryos. The typical lesions observed were no somite formation, incomplete eye and head development, tail curvature, weak pigmentation (≤48 hours postfertilization (hpf)), kyphosis, scoliosis, yolk sac deformity, and nonpigmentation (72 hpf). Also, embryo and larval mortality increased and hatching success decreased. The severity of abnormalities and mortalities were concentration- and compound-dependent. Of the compounds tested, 2,4-DNP was found to be highly toxic to the fish embryos following exposure. The median lethal concentrations and median effective concentrations for 2NP are 18.7 mg/L and 7.9 mg/L, respectively; the corresponding values for DNP are 9.65 mg/L and 3.05 mg/L for 48 h. The chorda deformity was the most sensitive endpoint measured. It is suggested that the embryotoxicity may be mediated by an oxidative phosphorylation uncoupling mechanism. This article is the first to describe the teratogenicity and embryotoxicity of two NPs to the early life stages of zebrafish.

Genotoxic effects of water pollution on two fish species living in Karasu River, Erzurum, Turkey.

Karasu River, which is the only river in the Erzurum plain, is the source of the Euphrates River (Eastern Anatolia of Turkey). The river is in a serious environmental situation as a result of pollution by agricultural and industrial sewage and domestic discharges. The present study aims to evaluate genotoxic effects of toxic metals in chub, Leuciscus cephalus, and transcaucasian barb, Capoeta capoeta, collected from contaminated site of the Karasu River, in comparison with fish from an unpolluted reference site. Heavy metal concentrations in surface water of the river were determined. The condition factor (CF) was taken as a general biomarker of the health of the fish, and genotoxicity assays such as micronucleus (MN) and other nuclear abnormalities (NA) were carried out on the fish species studied. MN and NA such as kidney-shaped nucleus, notched nucleus, binucleated, lobed nucleus, and blebbed nucleus were assessed in peripheral blood erythrocytes, gill epithelial cells, and liver cells of the fish. A significant decrease in CF values associated with a significant elevation in MN and NA frequencies was observed in fish collected from the polluted sites compared with those from the reference site. Results of the current study show the significance of integrating a set of biomarkers to identify the effects of anthropogenic pollution. High concentrations of heavy metals have a potential genotoxic effects, and the toxicity is possibly related to industrial, agricultural, and domestic activities.

Acute toxic effects of fenpyroximate acaricide on Guppy (Poecilia reticulata Peters, 1859).

Fenpyroximate (FP), an acaricide, is widely used in the prevention of acarids (mites) in fruit plant gardens. In this study, the acute toxic effects of different concentrations of FP were investigated using adult guppy (Poecilia reticulata Peters, 1859). Guppy adults were exposed to a range of FP concentrations (25, 50, 75, 100, 125, and 150 µg/L) during 48 h. Static method, which is one of the acute toxicity experiments, has been used in this study. According to probit analysis, the 48-h median lethal concentration (LC50) value of FP at 26°C was found to be 72.821 µg/L. Sublethal exposures were predetermined based on 48-h LC50 value. Guppies were exposed to low concentrations (15, 25, and 50 µg/L) of FP for 48 h. Signs of paralysis and behavior deformations were monitored every 12 h in a number of live and dead adults. Low concentrations of FP were also responsible for erratic swimming, loss of equilibrium, and being lethargic. Liver histology revealed several pathological damages including congestion, picnotic nucleus, sinusoidal dilatation, increase in melanomacrophagic centers, and endothelial degeneration. Finally, the toxicity test results provided 48-h LC50 value for FP, and low concentrations of FP can be highly detrimental to guppy adults with clear evidence of behavioral and histologic effects.