Stearidonic Acid-Enriched Buglossoides arvensis Oil Alleviates High-Fat Diet-Induced Hepatic Lipid Accumulation and Inflammation via AMPK/SIRT1 Activation in Rats

Background: Buglossoides arvensis oil (BO) is rich in plant-based omega-3 polyunsaturated fatty acids (n–3 PUFAs), including stearidonic acid (SDA). Dietary oils enriched with n–3 PUFAs have been shown to exert beneficial effects on inflammation and lipid metabolism; however, the effects of SDA-enriched BO (SBO) remain unclear. Objectives: This study aimed to evaluate the effects of SBO (n–3 PUFA: 67.1%, SDA: 38.5%) included in a high-fat (HF; 45% kcal from fat) diet on hepatic lipid accumulation and inflammation. Methods: Four-week-old male Sprague–Dawley rats were randomly divided into 3 groups (n = 6/group) and fed different diets for 9 wk: HF, HF with 10% BO (HF + BO), and HF with 10% SBO (HF + SBO) diet groups. At the end of the experiment, we analyzed lipid profiles in the serum and liver; assessed the expression of genes involved in lipid metabolism and inflammation by reverse transcription-quantitative polymerase chain reaction; measured inflammatory cytokines protein concentrations; and evaluated the activity of adenosine monophosphate-activated protein kinase (AMPK), sirtuin 1 (SIRT1), and nuclear factor kappa B (NF-κB). Results: HF + SBO group significantly reduced bodyweight and hepatic lipid accumulation compared with HF diet feeding (P < 0.05). Serum and hepatic lipid concentrations were significantly lower, whereas fecal lipid excretion was significantly higher in the HF + SBO group compared with the HF group (P < 0.05). The expression of lipid metabolism-related genes was significantly downregulated in the HF + SBO group, and AMPK and SIRT1 activity were increased 1.53- and 2.28-fold, respectively, compared with the HF group (P < 0.05). BO and SBO intake inhibited NF-κB activation by 27.5% and 41.8%, respectively, and reduced the mRNA and protein expression levels of inflammatory cytokines compared with HF diet feeding (P < 0.05). Moreover, SBO was more effective than BO in this regard. Conclusions: These findings suggest that SBO more effectively mitigates hepatic lipid accumulation and inflammation in rats fed HF diet, a phenomenon partly related to the increased activation of AMPK and SIRT1. This indicates that SBO may provide greater benefits than BO in improving lipid metabolism and inflammatory responses.