Related Experiment Video
Updated: Jul 13, 2026
Cytotoxicity Assays with Zebrafish Cell Lines
Published on: January 6, 2023
Acute and subacute toxic effects produced by microcystin-YR on the fish cell lines RTG-2 and PLHC-1
S Pichardo1, A Jos, J L Zurita
1Area of Toxicology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
Abstract:
Approximately 80 microcystins (MCs) variants have been isolated in surface water worldwide. The toxicity of the most frequently MCs are encountered, MC-LR and MC-RR, has been extensively studied in humans and animals. However, studies dealing with MC-YR toxicity are still scarce. In this work, the toxic effects of MC-YR were investigated in the fish cell line PLHC-1, derived from a hepatocellular carcinoma of the topminnow Poeciliopsis lucida, and RTG-2 fibroblast-like cells derived from the gonads of rainbow trout Oncorhynchus mykiss. After 48 h, morphological and biochemical changes (total protein content, neutral red uptake and methylthiazol tetrazolium salt metabolization) were determined. The most sensitive endpoint for both cell lines was the reduction of total protein content, with EC(50) values of 35 microM for PLHC-1 cells and 67 microM for the RTG-2 cell line. Lysosomal function and methylthiazol tetrazolium salt metabolization were stimulated at low concentrations, while they decreased at high doses. Increase of piknotic cells, rounding effects, reduction in cell number and cell size, hydropic degeneration, and death mainly by necrosis but also by apoptosis were observed in the morphological study. Furthermore, PLHC-1 cells are more sensitive than RTG-2 cells to MC-YR exposure. These results were similar to those obtained when both cell lines were exposed for 24h to a Microcystis aeruginosa isolated strain extract containing MC-LR.
Insights
Microcystin-YR (MC-YR) toxicity was studied in fish cells. MC-YR reduced total protein content, showing PLHC-1 cells were more sensitive than RTG-2 cells.
Area of Science:
- Environmental toxicology
- Aquatic toxicology
- Cell biology
Background:
- Microcystins (MCs) are prevalent cyanotoxins, with MC-LR and MC-RR extensively studied.
- MC-YR toxicity data, particularly in aquatic organisms, remains limited.
Purpose of the Study:
- To investigate the toxic effects of MC-YR on two fish cell lines: PLHC-1 (topminnow liver carcinoma) and RTG-2 (rainbow trout gonads).
- To compare the sensitivity of these cell lines to MC-YR exposure.
Main Methods:
- Exposure of PLHC-1 and RTG-2 cells to MC-YR for 48 hours.
- Assessment of morphological changes (cell number, size, morphology).
- Biochemical assays including total protein content, neutral red uptake, and MTT assay.
Main Results:
- Reduction in total protein content was the most sensitive endpoint, with EC50 values of 35 µM (PLHC-1) and 67 µM (RTG-2).
- Lysosomal function and MTT metabolism were stimulated at low MC-YR concentrations but inhibited at high concentrations.
- Morphological changes included cell shrinkage, rounding, necrosis, and apoptosis, with PLHC-1 cells exhibiting higher sensitivity.
Conclusions:
- MC-YR induces significant morphological and biochemical alterations in fish cell lines.
- PLHC-1 cells are more susceptible to MC-YR toxicity than RTG-2 cells.
- MC-YR toxicity profiles show similarities to MC-LR, highlighting its potential ecological risk.
