Combined effects of nano-TiO2 and hexavalent chromium towards marine crustacean Artemia salina

Abstract

There has been a significant increased concern of the impact of the toxicity of multiple contaminants in the marine environment. Thus, this study was aimed at determining whether the interaction between nano-TiO 2 and Cr(VI) would modulate their toxic effects with the marine crustacean, Artemia salina. Nano-TiO 2 agglomerated in artificial sea water (ASW) and readily formed micron-sized particles that settled down in the medium. The addition of Cr(VI) to nano-TiO 2 aggravated their agglomeration through sorption of Cr(VI) onto nano-TiO 2 . This was reflected by a decrease in the residual concentration of Cr in the suspension. Acute toxicity tests performed using pristine nano-TiO 2 (0.25, 0.5, 1, 2, and 4 mg/L) and Cr(VI) (0.125, 0.25, 0.5, and 1 mg/L) displayed a concentration dependent rise in the mortality of Artemia salina. To examine the effects of mixtures of nano-TiO 2 and Cr(VI) on Artemia salina, two groups of experiments were designed. The former group studied the toxic effect of nano-TiO 2 (0.5, 1, 2, and 4 mg/L) with a fixed concentration (0.125 mg/L) of Cr(VI). While the latter group studied the toxicity of Cr(VI) (0.25, 0.5, and 1 mg/L) with a fixed concentration (0.25 mg/L) of nano-TiO 2 . The toxic effects of nano-TiO 2 was not significantly reduced at a fixed concentration of Cr(VI) but in contrast, a significant reduction in the Cr(VI) toxicity by fixed concentration of nano-TiO 2 was observed. Toxicity data was well supported by an independent action model that proved the mode of action between nano-TiO 2 and Cr(VI) to be antagonistic. Furthermore, ROS generation and measurement of antioxidant enzyme activities were also in line with toxicity results. From this study, the modification of Cr(VI) toxicity at fixed concentration of nano-TiO 2 could have a huge impact on the reduction in Cr(VI) toxicity across trophic levels.

Mixture toxicity of TiO2 NPs and tetracycline at two trophic levels in the marine ecosystem: Chlorella sp. and Artemia salina

“…Pristine TiO2 NPs induced dose-dependent acute toxicity in A. salina, which was in line with the previous findings of Thiagarajan et al (2020). Accumulation of TiO2 NPs in the gut is considered as one of the mechanisms by which TiO2 NPs may induce mortality in A. salina.…”

Unravelling the suitability of Branchinecta gaini as a potential biomonitor of contaminants of emerging concern in the Antarctic Peninsula region

“…To date, nano-ecotoxicity studies evaluating the acute effects of NPs on crustaceans at the molecular level have mostly considered gene expression related to antioxidant enzymes such as Sod, catalase, GPx and glutathione S-transferase (Kim et al 2010, Clemente et al 2014, Kögel et al 2020). Recently, Thiagarajan et al (2020) showed that n-TiO 2 caused reduced Sod activity in Artemia salina . It is well known that n-TiO 2 increases ROS production and could activate antioxidant defence mechanisms such as Sod and GPx to protect cells from oxidative stress.…”

Synergistic impact of nanoplastics and nanopesticides on Artemia salina and toxicity analysis

“…The combined toxicity of NPER and PSNPs was validated by using an independent action model (Table 2). When a PSNP concentration of 100 mg L −1 and NPER concentration of 2 mg L −1 were combined, the R I values was observed to be decreased below 1, 27 proving their antagonistic on Artemia salina. However, when the concentration of NPER was increased from 4 to 32 mg L −1 , the complex exhibited synergistic effects on the organisms.…”

“…The absorbance of the reaction mixture at 560 nm was measured using a microplate reader -BIORAD. 27 The most widely used technique for studying lipid peroxidation in biological systems is the malondialdehyde (MDA) assay, which measures thiobarbituric acid-reactive compounds (TBARS) by the thiobarbituric acid (TBA) test. 28 As a gauge of oxidative stress, TBARS were evaluated to ascertain the lipid peroxidation products.…”