da Silva Rangel Leonardo, Gonzaga Daniel Tadeu Gomes, da Silva Ana Cláudia Rodrigues, von Ranke Natalia Lindmar, Rodrigues Carlos Rangel, Santos José Augusto Albuquerque Dos, Boechat Nubia, Gomes Keyla Nunes Farias, Teixeira Guilherme Pegas, Faria Robson Xavier
Laboratory for Evaluation and Promotion of Evaluation and Promotion of Environmental Health (LAPSA), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, Brazil.
Department of Pharmacy, West Zone Campus, State University of Rio de Janeiro (UERJ), Rio de Janeiro 20550-013, Brazil.
Pharmaceuticals (Basel). 2025 Mar 18;18(3):429. doi: 10.3390/ph18030429.
Schistosomiasis is caused by flatworms of the genus , for which mollusks of the genus are intermediate hosts. Niclosamide (NCL) is a molluscicide recommended by the World Health Organization (WHO) for control of . Although effective, it is expensive and environmentally toxic, which raises concerns regarding its widespread use. As a result, we explored new synthetic substances as alternative strategies for controlling . We evaluated the molluscicidal activity of 2-(1-py-razol-1-)-1,3,4-thiadiazole and 2-(4,5-dihydro-1-pyrazol-1-)-1,3,4-thiadiazole derivatives against snails and embryos, as well as cercariae (infective larvae). Adult and young snails were added to 24-well plates containing 20 synthetic compounds from the PDAN series for initial screening over 96 h at a concentration of 100 ppm. Water and NCL (2 ppm) were used as the negative and positive controls, respectively. Active compounds in the adult assay were selected for the tests vs. embryos and cercariae. In the initial screen, only PDAN 52 (63 ± 4%) and 79 (12 ± 3%) showed molluscicidal activity at a concentration of 100 ppm up to 48 h. Consequently, we selected only PDAN 52. The LC value found in the tests on embryos after 24 h of treatment was 20 ± 2 ppm and, after 48 h, it was 4 ± 0.5 ppm. Against cercariae, we measured an LC value of 68 ± 5 ppm after 4 h of treatment. PDAN 52 did not induce marked toxicity against a second mollusk, , after 48 h of exposure. We highlight the promising molluscicidal activity of PDAN 52 against different developmental stages of the mollusk, , as well the infective larvae of .
血吸虫病由血吸虫属的扁虫引起，其中钉螺属的软体动物是中间宿主。氯硝柳胺（NCL）是世界卫生组织（WHO）推荐用于控制血吸虫病的杀螺剂。尽管它有效，但价格昂贵且对环境有毒，这引发了对其广泛使用的担忧。因此，我们探索了新的合成物质作为控制血吸虫病的替代策略。我们评估了2-(1-吡唑-1-基)-1,3,4-噻二唑和2-(4,5-二氢-1-吡唑-1-基)-1,3,4-噻二唑衍生物对钉螺及其胚胎以及尾蚴（感染性幼虫）的杀螺活性。将成年和幼年钉螺添加到含有20种来自PDAN系列合成化合物的24孔板中，以100 ppm的浓度进行96小时的初步筛选。水和NCL（2 ppm）分别用作阴性和阳性对照。在成年钉螺试验中筛选出的活性化合物用于对胚胎和尾蚴的测试。在初步筛选中，只有PDAN 52（63±4%）和79（12±3%）在100 ppm的浓度下48小时内表现出杀螺活性。因此，我们只选择了PDAN 52。在对胚胎的测试中，处理24小时后的LC值为20±2 ppm，48小时后为4±0.5 ppm。对于尾蚴，处理4小时后的LC值为68±5 ppm。暴露48小时后，PDAN 52对另一种软体动物没有明显毒性。我们强调了PDAN 52对钉螺不同发育阶段以及血吸虫感染性幼虫具有良好的杀螺活性。
