Environmental and human exposure relevant dose analysis of triclosan on larval zebrafish heart rate using microscopic observation for risk assessment applications

Abstract

Aim: The current study's goal is to determine the impact of triclosan (TCS) concentrations in the environment and from human exposure on zebrafish larvae heart rate. Materials and Methods: Chemicals: TCS [CAS:3380-34-5, Purity-99%] was purchased from Loba Chemie, Mumbai, India. Stock solution of 1000 ppm was prepared using ethanol and autoclave water as solvents and stored at -20˚C in an amber coloured bottle. Maintenance of zebrafish and egg collection: Wild type, adult zebrafish were purchased from a local cultivator and are maintained in a light and dark cycle of 14:10h at 26±1 °C under static conditions. In order to obtain embryos, breeding groups were housed in a specific spawning tank in a male to female ratio of 1:1. Embryo toxicity assay: This work includes 2 groups and a total sample size of 106. Group 1 analyzed the environmental exposure relevant dose of TCS on larval zebrafish hatching rate whereas group 2 analyzed the human exposure relevant dose analysis of TCS on larval zebrafish hatching rate. Embryos were sorted out for each exposure group in petri plates, with n=53 embryos per plate and were exposed to TCS from 4 hpf - 96 hpf. Other conditions required for the validation of this study were maintained as stated by the OECD in the fish embryo toxicity assay guidelines. All the experiments were carried out in triplicate. Heart rate: Heart rate was recorded for 60 seconds and was observed in 96 hpf larvae using microscopy. The parameters were maintained as confidential ratio of 95%, threshold 0.01, G power 80% and enrolment ratio as 1. Result: It was observed that embryos exposed to an environment-relevant exposure dose showed reduced heart rate (41.05±1.30) compared to human exposure relevant dose (56.15± 1.47). There exists a statistically insignificant difference between the two groups (p=0.25). Conclusion: The current study results provide preliminary theoretical data revealing the impact of TCS on developing heart which has implications for pollutant-induced cardiac diseases in humans.

Imprint

P. Sushmitha, I. Praveen kumar. Environmental and Human Exposure Relevant Dose Analysis of Triclosan on Larval Zebrafish Heart Rate using Microscopic Observation for Risk Assessment Applications. Cardiometry; Issue 25; December 2022; p.1738-1743; DOI: 10.18137/cardiometry.2022.25.17381743; Available from: https://www.cardiometry.net/issues/no25-december-2022/environmental-human-exposure-relevant