Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro 3810-193, Portugal.
Interuniversity Consortium of Marine Biology and Applied Ecology "G. Bacci", Livorno 57128, Italy.
Aquat Toxicol. 2022 Sep;250:106263. doi: 10.1016/j.aquatox.2022.106263. Epub 2022 Aug 3.
Marine-coastal systems have been increasingly exposed to multiple stressors, including anthropogenic pollution and variations of Climate Change (CC) related factors, whose coexistence could create associated environmental and ecotoxicological risks. Among emergent stressors, 4-methylbenzylidenecamphor (4-MBC) and benzophenone-3 (BP-3) UV-filters are compounds widely used in increasing consumer products, resulting in their ubiquity in aquatic environments and possible pressing challenges on gamete susceptibility. Since most marine invertebrates reproduce by external fertilization, after spawning, gametes may be exposed to several pressures, affecting reproductive success and outcome. The present study focuses on the spermiotoxicity of the environmentally relevant UV-filters 4-MBC and BP-3 combined with salinity shifts, as potential modulators of their harmful effects. For this, Mytilus galloprovincialis male gametes were exposed in vitro to environmentally relevant and slightly higher concentrations (1, 10 and 100 µg/L) of 4-MBC or BP-3 under three different salinities (S 20, 30 and 40). Sperm quality endpoints associated with oxidative status, viability, motility, kinetics, and genotoxicity were evaluated. Similarities and differences in sperm responses among all conditions were highlighted by principal coordinates analysis (PCO). Results showed that salinity acting alone posed greater sperms impairments at the lowest (20) and highest (40) tested levels. When salinity acts as a co-varying stressor, salinity-dominant interactive effects resulted evident, especially for 4-MBC at S 40 and BP-3 at S 20. These findings were pointed out as the worst exposure conditions for M. galloprovincialis sperms, since caused major toxicological effects in terms of: (I) oxidative stress, sperm structural impairments, motility and kinetic alterations in 4-MBC-exposed sperms; (II) DNA damage, compromised mitochondrial activity and hyperactivation in BP-3-exposed ones. Overall, it stands out that salinity influences UV-filter toxicological pathways and, thereby, the potential environmental risk of these contaminants on M. galloprovincialis male gametes, especially in an expected salinity stress scenario.
海洋-沿海系统越来越多地受到多种胁迫因素的影响，包括人为污染和气候变化（CC）相关因素的变化，这些因素的共存可能会产生相关的环境和生态毒理学风险。在新兴的胁迫因素中，4-甲基苄叉基樟脑（4-MBC）和二苯甲酮-3（BP-3）紫外线滤光剂是广泛应用于消费品的化合物，导致它们在水生环境中普遍存在，并可能对配子易感性造成紧迫的挑战。由于大多数海洋无脊椎动物通过体外受精繁殖，在产卵后，配子可能会暴露于多种压力下，从而影响繁殖的成功和结果。本研究集中于环境相关的紫外线滤光剂 4-MBC 和 BP-3 的精子毒性，以及盐度变化，作为其有害影响的潜在调节剂。为此，在三种不同盐度（S 20、30 和 40）下，体外将海洋贻贝（Mytilus galloprovincialis）雄性配子暴露于环境相关的和略高浓度（1、10 和 100μg/L）的 4-MBC 或 BP-3 中。评估了与氧化状态、活力、运动性、动力学和遗传毒性相关的精子质量终点。通过主坐标分析（PCO）突出了所有条件下精子反应的相似性和差异。结果表明，单独的盐度在最低（20）和最高（40）测试水平下对精子造成更大的损伤。当盐度作为一个共同变化的胁迫因素时，盐度主导的相互作用效应变得明显，特别是在 S 40 下的 4-MBC 和 S 20 下的 BP-3。这些发现被指出是海洋贻贝精子最恶劣的暴露条件，因为它们在以下方面造成了主要的毒理学影响：（I）氧化应激、精子结构损伤、4-MBC 暴露精子的运动性和动力学改变；（II）DNA 损伤、线粒体活性受损和 BP-3 暴露精子的超激活。总的来说，值得注意的是，盐度会影响紫外线滤光剂的毒理学途径，从而影响这些污染物对海洋贻贝雄性配子的潜在环境风险，特别是在预期的盐度胁迫情景下。
