Fig 2: Didymin protects AML12 cells against PA‐induced lipid deposition by activating Sirt1. A Principal component analysis (PCA) of the RNA-sequencing data of AML12 cells. B Volcano-plot of RNA-seq results for PA + Didymin vs. PA. C KEGG analysis of the enrichment pathways. D GO Process (GO-P) analysis. Heatmaps of gene expression profiles related to (E) mitochondrial function, (F) autophagy, and (G) apoptosis based on the RNA-seq data set. (n = 4) (H) Western blot analysis of Sirt1 in AML12 cells (n = 3). I Sirt1 deacetylase activity in AML12 cells (n = 3). J Interactive sites between Didymin and Sirt1 by docking analysis. K MST analysis of the interaction between Didymin and Sirt1 (n = 3). L Sirt1 recombinant protein deacetylase activity (n = 4). M TG contents in AML12 cells (n = 4). N Oil red O staining of AML12 cells (Scale bar = 20 μm). Data are expressed as mean ± SD. *P < 0.05, **P < 0.01, ****P < 0.0001 PA vs. PA + Didymin. #P < 0.05, ##P < 0.01, ###P < 0.001, ####P < 0.0001 control vs. PA. PA palmitic acid, MST MicroScale Thermophoresis, TG triglyceride

Fig 3: Didymin suppresses apoptosis by activating Sirt1 in PA-treated AML12 cells. A Representative images of TUNEL staining in AML12 cells (Scale bar = 100 μm). Quantification of the percentage of TUNEL-positive cells (n = 3). B Apoptosis analysis of AML12 cells by flow cytometry. And the results of quantitative analyses of apoptosis rate (n = 3). C Western blot analysis of Bax, Bcl2, cleaved-caspase3, and caspase3 proteins in AML12 cells (n = 3). Data are expressed as mean ± SD. *P < 0.05, ***P < 0.001 PA vs. PA + Didymin. # P < 0.05, ## P < 0.01, ### P < 0.001, #### P < 0.0001 control vs. PA. PA palmitic acid, TUNEL TdT-mediated dUTP Nick-End labeling, Bax Bcl-2-associated X protein, Bcl2 B-cell lymphoma 2

Fig 4: Schematic representation of Didymin alleviates MAFLD through the Sirt1 pathway. Didymin binds to SIRT1 protein and activates its deacetylase activity, which in turn deacetylates FoxO3a and PGC-1α and enhances their activity. FoxO3a further increases the expression level of SIRT1 and promotes the process of lipophagy. The increase in lipophagy activity can further inhibit cell apoptosis. PGC-1α enhances mitochondrial biosynthesis and improves mitochondrial function by promoting the transcription of NRF1 and TFAM. PGC-1α proliferative activated receptor γ coactivator 1α, NRF1 nuclear respiratory factor 1, TFAM mitochondrial transcription factor A, FoxO3a Foxkhead Box Class O 3a, PLIN2 perilipin 2, LAMP1 lysosomal associated membrane protein 1, Bax Bcl-2-associated X protein, Bcl2 B-cell lymphoma 2

Fig 5: Didymin protects mice against high-fat diet-induced MAFLD by activating Sirt1. A Graphical description of the experimental design of this study. B Body weight (n = 6–8). C Liver weight. D Liver index. E–J Serum level of TG, TC, ALT, AST, LDL and HDL (n = 5–6). K Representative H&E, oil red O, Masson, and PAS staining of hepatic sections (Scale bar = 50 μm). L Transmission electron microscopy figures of hepatocytes, arrows show lipid droplets (Scale bar = 1.2 μm). All values were expressed as the mean ± SD. *P < 0.05, **P < 0.01, ****P < 0.0001 PA vs. PA + Didymin. ##P < 0.01, ####P < 0.0001 control vs. MAFLD. PA palmitic acid, MAFLD metabolic associated fatty liver disease, TG triglyceride, TC total cholesterol, ALT alanine aminotransferase, AST aspartate aminotransferase, LDL low-density lipoprotein, HDL high-density lipoprotein, H&E hematoxylin, and eosin