Effects of Quercetin on the Green Hydra (Hydra viridissima Pallas, 1766)

Abstract

Effects of quercetin on the green hydra, Hydra viridissima Pallas, and its endosymbiotic alga were studied under laboratory conditions. Quercetin is the most studied flavonoid known for its ability to act as an antioxidant, but it can also show a pro-oxidative effect. Green hydras were treated with four concentrations of quercetin (0.12 g/L, 0.2 g/L, 0.25 g/L and 0.3 g/L) for three days and compared to the control group of animals. Through the use of light microscopy, morphometry and macroscopic observations the results showed morphological changes in the hydra body as well as behavioral changes: depigmentation, migration, deformation, disordered locomotion, diminished reactions to mechanical stimuli and mortality. Further, different histopathological changes in the hydra body were detected. Different changes were monitored in the endosymbiotic alga: cell viability, division, shape and size of cells and chloroplasts, the level of damage and intensity of green color. Based on our results, the most important conclusion is that quercetin has a possible pro-oxidative effect on the green hydra.

Ecotoxicological Effects of Sodium Metasilicate on Two Hydra Species, Hydra viridissima Pallas, 1766 and Hydra oligactis Pallas, 1766

“…The brown hydras exhibited greater changes in body contraction than the green hydras. The increased body relaxation of the control group of brown hydras may have been due to their greater susceptibility to high temperatures and/or oxygen deficiency inside the Petri dishes they were kept in [61]. If this was in fact the case, the relaxation of the body could be a way of increasing the oxygen diffusion inside the body.…”