Investigation of cytotoxicity using Oncorhynchus mykiss (Rainbow trout) liver cells (RTL-W1) in determination of environmental toxicity caused by 2,4-D and glyphosate based herbicides

Industrial and agricultural activities, which are the result of development and change, increase the chemical burden of the environment; because many and many types of chemicals are circulating in the environment. These chemicals or chemical mixtures can be a potential threat to the water biota. Regulatory agencies recommend conducting fish toxicity tests. But, these regulations for the protection of aquatic organisms mean that hundreds of chemicals are evaluated in vivo on numerous fish. However, the 3R approach, which is a guide to the ethical use of animals in experiments, has gained more importance recently. Due to ethical concerns regarding in vivo testing, efforts are ongoing to develop alternative testing methods that may help reduce their use in environmental hazard assessments. In this thesis study, it is aimed to obtain findings that will contribute significantly to environmental risk assessment studies by evaluating herbicides and their mixtures using in vitro and in silico methods in accordance with the 3R approach. The cytotoxic and lethal effects of the test chemicals are listed as Hektafermin® > 2,4-D > Roundup Star® > Glyphosate, according to in vitro and in silico test results. When RTL-W1 EC50, QSAR Toolbox EC50 and QSAR Toolbox LC50 values are examined, living things are more sensitive to the test substances than cells. Commercial herbicide mixtures have greater cytotoxic and lethal effects than analytical standard mixtures, individual herbicide formulations, and analytical standards. The data obtained clearly showed that Roundup Star® and Hektafermin® herbicide formulations and mixtures are more toxic than the active ingredients. The results are important in terms of ecotoxicology and may be useful in environmental risk assessment studies. Keywords: 2,4-D, Glyphosate, Herbicides mixture, OECD QSAR Toolbox, RTL-W1