Fig. 6

Serum metabolomics for SIN treated DN rats. PCA score plot of DN vs. SIN (20 mg/kg) group and DN vs. SIN (40 mg/kg) group (A-B). OPLS-DA score plot of DN vs. SIN (20 mg/kg) group and DN vs. SIN (40 mg/kg) group (C-D); S-plot was used to select the changes of metabolites, the variables in red were the lipids with VIP > 1.0. S-plot of DN vs. SIN (20 mg/kg) group and DN vs. SIN (40 mg/kg) group (E-F). VIP value analysis of DN vs. SIN (20 mg/kg) group and DN vs. SIN (40 mg/kg) group (G-H). Heatmap of Pearson’s correlations of DN vs. SIN (20 mg/kg) group and DN vs. SIN (40 mg/kg) group (I-J). Heatmap of different metabolites of DN vs. SIN (20 mg/kg) group and DN vs. SIN (40 mg/kg) group (K-L). KEGG enrichment analysis of different metabolites of DN vs. SIN (20 mg/kg) group and DN vs. SIN (40 mg/kg) group (M-N). Summary of pathway analysis with MetaboAnalyst 5.0: (1) Linoleic acid metabolism; (2) alpha-Linolenic acid metabolism; (3) Arginine biosynthesis; (4) Retinol metabolism; (5) Fatty acid elongation; (6) Arginine and proline metabolism; (7) Arachidonic acid metabolism; (8) Glycerophospholipid metabolism; (9) Phenylalanine metabolism; (10) Histidine metabolism in DN vs. SIN (20 mg/kg) group (O). (1) Retinol metabolism; (2) Arginine biosynthesis; (3) Biosynthesis of unsaturated fatty acids; (4) Sphingolipid metabolism; (5) Linoleic acid metabolism; (6) Aminoacyl-tRNA biosynthesis; (7) Arachidonic acid metabolism; (8) alpha-Linolenic acid metabolism; (9) Tryptophan metabolism; (10) Glycerophospholipid metabolism in DN vs. SIN (40 mg/kg) group (P). Venn diagram of the overlapping metabolites of DN vs. SIN (20 mg/kg) group and DN vs. SIN (40 mg/kg) group (Q)