benzofurans and Schistosomiasis

In this work, two synthetic aurones revealed moderate schistosomicidal potential in in vitro and in vivo assays. Aurones (1) and (2) promoted changes in tegument integrity and motor activity, leading to death of adult Schistosoma mansoni worms in in vitro assays. When administered orally (two doses of 50 mg/kg) in experimentally infected animals, synthetic aurones (1) and (2) promoted reductions of 56.20 % and 57.61 % of the parasite load and stimulated the displacement towards the liver of the remaining adult worms. The oogram analysis revealed that the treatment with both aurones interferes with the egg development kinetics in the intestinal tissue. Seeking an action target for compounds (1) and (2), the connection with NTPDases enzymes, recognized as important therapeutic targets for S. mansoni, was evaluated. Molecular docking studies have shown promising results. The dataset reveals the anthelmintic character of these compounds, which can be used in the development of new therapies for schistosomiasis.

Topics: Administration, Oral; Animals; Anthelmintics; Benzofurans; Dose-Response Relationship, Drug; Female; Mice; Molecular Structure; Schistosoma mansoni; Schistosomiasis

Japanese schistosomiasis was endemic in Dongting Lake, the second largest freshwater lake in China. The technical sodium pentachlorophenate (Na-PCP) was widely used during the period between the early 1960s and early 1990s to kill oncomelania, the intermediate host of Schistosomes. However, polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) also contaminated the environment of Dongting Lake due to trace impurities of Na-PCP. In this study, 13 species of freshwater fish were collected from Dongting Lake and analyzed in wet and dry seasons. Temporal (wet and dry season) variations in PCDD/Fs in fishes from Dongting Lake were observed. The concentration of PCDD/Fs was considerably higher in the wet season than in the dry season and in areas in China where Na-PCP was not applied. The higher level of PCDD/Fs in the wet season may be attributed to the use of Na-PCP in the past and to the increase in the migration of PCDD/Fs from sediments to water in the wet season. The results indicate that the risk of PCDD/Fs contamination is connected with prior consumption of fishes that live in the Na-PCP application area. However, there was no difference in the concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) between the wet and dry seasons.

Topics: Animals; Benzofurans; China; Dibenzofurans, Polychlorinated; Environmental Monitoring; Fishes; Halogenated Diphenyl Ethers; Lakes; Pentachlorophenol; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Schistosomiasis; Seasons; Water Pollutants, Chemical

In Brazil, the snail Biomphalaria glabrata is the most important vector of schistosomiasis due to its wide geographical distribution, high infection rate and efficient disease transmission. Among the methods of schistosomiasis control, the World Health Organization recommends the use of synthetic molluscicides, such as niclosamide. However, different substances of natural origin have been tested as alternatives for the control or eradication of mollusks. The literature describes the antitumor, antimicrobial and antiviral properties of usnic acid as well as other important activities of common interest between medicine and the environment. However, usnic acid has a low degree of water solubility, which can be a limiting factor for its use, especially in aquatic environments, since the organic solvents commonly used to solubilize this substance can have toxic effects on aquatic biota. Thus, the aim of the present study was to test the potassium salt of usnic acid (potassium usnate) with regard to molluscicidal activity and toxicity to brine shrimp (Artemia salina). To obtain potassium usnate, usnic acid was extracted with diethyl ether isolated and purified from the lichen Cladonia substellata. Biological assays were performed with embryos and adult snails of B. glabrata exposed for 24 h to the usnate solution solubilized in dechlorinated water at 2.5; 5 and 10 µg/ml for embryos, 0.5; 0.9; 1;5 and 10 µg/ml for mollusks and 0.5; 1; 5; 10 µg/ml for A. salina. The lowest lethal concentration for the embryos and adult snails was 10 and 1 µg/ml, respectively. No toxicity to A. salina was found. The results show that modified usnic acid has increased solubility (100%) without losing its biological activity and may be a viable alternative for the control of B. glabrata.

Topics: Animals; Benzofurans; Biomphalaria; Molluscacides; Schistosoma mansoni; Schistosomiasis

Spatial and temporal distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) was explored in the Dongting Lake area. The concentrations of total PCDD/Fs ranged from 15.4 to 38.9 pg I-TEQ g(-1) in surface sediments and 0.55 to 38.9 pg I-TEQ g(-1) for sediment core. The vertical distributions of PCDD/Fs in the sediment core reflected the past history of using Na-PCP and the impact of the massive flood events on the distribution of PCDD/Fs to some extent. The sediment still acts as significant PCDD/F sources and they would pose a risk to sensitive species, resulting in the risk for human exposure to PCDD/F.

Topics: Benzofurans; China; Dibenzofurans, Polychlorinated; Geologic Sediments; Limit of Detection; Polychlorinated Dibenzodioxins; Schistosomiasis

Schistosomiasis has prevailed in some areas of China for a long time. Chinese technical sodium pentachlorophenate (Na-PCP) has been used to control the spread of snail-borne schistosomiasis since the 1960s. Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), impurities contained in the Na-PCP, enter the soil and may accumulate in the food chain. In order to evaluate their potentially harmful effects on local residents, 50 breast milk samples and 20 blood samples were collected in 2004 from residents in the Dongting Lake area, one of China's known schistosomiasis areas. Levels of 17 PCDD/F congeners were measured in all samples, and DNA damage was simultaneously assessed in blood samples. The PCDD/F congener distribution patterns in human tissue samples from the Dongting Lake area were similar to those in Na-PCP, and the octachlorodibenzodioxin (OCDD) congener was predominant in all samples. We also had a primary investigation that the breast milk WHO-TEQ associated with some factors such as: age, dietary habit, body mass index (BMI) and the total menses times. In blood samples, the samples with higher OCDD level had higher DDS (DNA damage score) values than those samples with low OCDD level, which indicated that the higher DNA damage value in general population might be caused directly or indirectly by PCDD/Fs. The results also indicated that the WHO-TEQ values in blood were associated with age (r=0.6, p=0.007).

Topics: Adult; Benzofurans; China; Dibenzofurans, Polychlorinated; DNA Damage; Female; Humans; Milk, Human; Pentachlorophenol; Polychlorinated Dibenzodioxins; Schistosomiasis

Topics: Adult; Benzofurans; China; Dibenzofurans, Polychlorinated; Environmental Exposure; Female; Humans; Milk, Human; Pest Control; Polychlorinated Dibenzodioxins; Schistosomiasis; Soil Pollutants

An extensive investigation on the input, formation and fate of PCDD/Fs in a pulp mill using reeds as raw materials in China was carried out. The main PCDD/Fs input in the production process came from reeds, which may be contaminated by PCDD/Fs from sodium pentachlorophenate to control snailborne schistosomiasis. High levels of I-TEQ in the products were observed.

Topics: Animals; Benzofurans; China; Dibenzofurans, Polychlorinated; Environmental Monitoring; Industry; Insecticides; Manufactured Materials; Paper; Pentachlorophenol; Pest Control; Pesticide Residues; Polychlorinated Dibenzodioxins; Schistosomiasis; Snails

Topics: Benzofurans; China; Molluscacides; Pentachlorophenol; Pest Control; Polychlorinated Dibenzodioxins; Schistosomiasis; Soil Pollutants; Water Pollutants, Chemical

Topics: Animals; Benzofurans; Mice; Schistosomiasis; Schistosomicides