Toxicity, degradation and metabolic fate of ibuprofen on freshwater diatom Navicula sp

Tengda Ding; Mengting Yang; Junmin Zhang; Bo Yang; Kunde Lin; Juying Li; Jay Gan

doi:10.1016/j.jhazmat.2017.02.004

Toxicity, degradation and metabolic fate of ibuprofen on freshwater diatom Navicula sp

J Hazard Mater. 2017 May 15:330:127-134. doi: 10.1016/j.jhazmat.2017.02.004. Epub 2017 Feb 6.

Authors

Tengda Ding¹, Mengting Yang², Junmin Zhang², Bo Yang², Kunde Lin³, Juying Li⁴, Jay Gan⁵

Affiliations

¹ Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China; State Key Laboratory of Marine Environmental Science, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen 361005, China.
² Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
³ State Key Laboratory of Marine Environmental Science, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen 361005, China.
⁴ Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China. Electronic address: jyli@szu.edu.cn.
⁵ Department of Environmental Sciences, University of California, Riverside, CA 92521, United States.

PMID: 28214648
DOI: 10.1016/j.jhazmat.2017.02.004

Abstract

Ibuprofen (IBU) is one of the most widely used and frequently detected human pharmaceuticals in aquatic environment. However, the toxicity of IBU on diatom and its fate remain still unkown. In the present study, the toxicity of IBU on the diatom was evaluated by the algal growth rate, the chlorophyll-a and carotenoids contents. The degradation of IBU including in particular the potential for the formation of incomplete degradation products was also explored. Biochemical characteristics of Navicula sp. were significantly inhibited at IBU concentrations up to 50mgL^-1 after 10days of exposure. The degradation of IBU was retarded by Navicula sp. at low concentration (1mgL^-1), with t_1/2 being extended from 9.6±1.8 d to 12.0±1.5 d, indicating that Navicula sp. could prolong the exposure time of IBU. A total of 8 metabolites were identified by LC-MS/MS and the degradation pathway of IBU in Navicula sp. was proposed. Hydroxylation, acylation, demethylation, and glucuronidation contributed to IBU transformative reactions in diatom cells. These findings indicate that the presence of diatom Navicula sp. could hinder degradation of IBU, and IBU and/or its metabolites may pose high risks on aquatic ecosystem in natural waters.

Keywords: Degradation; Ibuprofen; Metabolites; Navicula sp.; Toxicity.

MeSH terms

Biodegradation, Environmental
Diatoms / drug effects*
Diatoms / growth & development
Diatoms / metabolism*
Ibuprofen / metabolism*
Ibuprofen / toxicity
Water Pollutants, Chemical / metabolism*
Water Pollutants, Chemical / toxicity

Substances

Water Pollutants, Chemical
Ibuprofen