QSTR Analysis of Acute Rat Oral Toxicity of Amide Pesticides

1. Introduction

The use of pesticides in agriculture has been in practice for long time. Sumeria used elemental sulphur dusting about 4,500 years ago as a pesticide and this was known to be use of the first pesticide. With the time, the development of newer pesticides was very quick. The use of pesticides is not only restricted to food/crop protection, but also in controlling many vector borne diseases like mosquito-borne disease malaria, dengue, etc. The subsequent toxicities (both living and non-living) associated with the indiscriminate use were the obvious observed outcomes and were/are regularly reported in the literature describing concerns related to the ecosystem. The nonstop development of pesticides and their use (≈2.5 million tons of pesticides used every year around the world) (Pimentel 1995) may perhaps become one of the causes of destruction of the ecosystem. Even many of the animal species are under the verge of extinction. Pesticide Action Network Europe (PAN) reported that many animal (mammals, birds, fish, bees, many amphibians, etc.) species are declining due to overuse of pesticides (https://www.tutorvista.com/biology/uses-of-amides; Rajput et al. 2018). The associated toxicity due to the widespread application of the above-mentioned classes of chemicals/pesticides is really a great concern looking at the ecotoxicological aspect as mentioned earlier also in the literatures (Garcia et al., 2012; Marouani et al., 2017; Choi et al., 2014). Among the different ecotoxicological endpoints, it is an important point of the interest to build a model for acute oral toxicity of chemicals including pesticides. Acute toxicity describes the adverse effects that occur in a short period of time by the single or multiple exposures of any chemicals substances. The rodent acute toxicity is given much attention due to day by day addition of a large number of diverse chemical classes in the database with toxic potential. Traditionally, toxicity information has been investigated by using animal models but for a huge number of inputs, it is practically impossible to evaluate the experimental toxicity considering the time, cost as well ethical window. Availability toxicity values of fewer congeners advocate alternative non-animal theoretical approaches for filling the data gaps in toxicity values. Quantitative structure-activity relationship (QSAR) is regarded as one of the most widely used in silico tool for toxicity estimation, risk assessment, and it helps to take regulatory decisions by many regulatory programs/agencies like registration, evaluation, authorisation and restriction of chemicals (REACH), European chemicals bureau (ECB), etc. (Nicolotti et al. 2014; Pavan et al. 2008).