Mass Spectrometry-Based Metabolomics Investigation on Two Different Seaweeds Under Arsenic Exposure

Abstract

Arsenic is a common toxic heavy metal contaminant that is widely present in the ocean, and seaweeds have a strong ability to concentrate arsenic, posing a potential risk to human health. This study first analyzed the arsenic content in two different seaweeds and then used an innovative method to categorize the seaweeds into low-arsenic and high-arsenic groups based on their arsenic exposure levels. Finally, a non-targeted metabolomic analysis based on mass spectrometry was conducted on seaweed from different arsenic exposure groups. The results indicated that as the arsenic concentration increased in the seaweeds, linolenic acid, tyrosine, pheophorbide a, riboflavin, and phenylalanine were upregulated, while arachidonic acid, eicosapentaenoic acid (EPA), betaine, and oleamide were downregulated. The following four key metabolic pathways involving unsaturated fatty acids and amino acids were identified: isoquinoline alkaloid biosynthesis, tyrosine metabolism, phenylalanine metabolism, and riboflavin metabolism. The identification of biomarkers and the characterization of key metabolic pathways will aid in the selection and breeding of low-arsenic-accumulating seaweed varieties, providing insights into the metabolic and detoxification mechanisms of arsenic in seaweeds.

Keywords: LC-MS; arsenic; metabolomics; pathways; seaweeds.

Figure 1

Schematic diagram of mass spectrometry-based metabolomics investigation on two different seaweeds under arsenic exposure.

Figure 2

Geographic sites of seaweed samples from different regions in China (SD, Shandong; ZJ, Zhejiang; Specific regions where the samples were collected, marked by the red triangles.)

Figure 3

The concentration of As in high-arsenic seaweed samples (A) and low-arsenic seaweed samples (B). (HS, High-arsenic seaweed samples; LS: Low-arsenic seaweed samples).

Figure 4

Score plot of PCA model (A); score plot of PLS-DA Model (B).

Figure 5

Metabolic pathways (A) and enrichment pathways (B) from the analysis of seaweed samples from different arsenic exposure groups. (Size of bubbles represents influence of pathway).

Figure 6

Relative intensities of metabolites in seaweeds under different arsenic exposures. ((A): the relative intensities of betaine, timnodonic acid, oleamide, and riboflavin; (B): the relative intensities of linolenic acid, arachidonic acid, tyrosine, pheophorbide a, and phenylalanine).