Antioxidant and lipid-lowering effects of freeze-dried kimchi cabbage and onion mediated via inhibition of adipogenesis in 3T3-L1 adipocytes

Background: Kimchi exhibits various beneficial effects on human health, which are ascribed to its ingredients, bioactive compounds, lactic acid bacteria, and metabolites. Objective: To explore the antioxidant and lipid-lowering effects of individual ingredients of freeze-dried kimchi in 3T3-L1 adipocytes. Design: The lipid-lowering effects of six kimchi ingredients were investigated using 3T3-L1 adipocytes. Their antioxidant activities, cytotoxicity, and the effect on triglyceride (TG) content, lipid accumulation, and obesity-associated biomarker expressions were examined. Results: Freeze-dried ginger exhibited the highest antioxidant activity, followed by kimchi cabbage and onion. Freeze-dried garlic and green onion showed cytotoxicity, and the TG content in freeze-dried ginger-treated cells was similar to that of the control. Freeze-dried kimchi cabbage- and onion-treated cells exhibited increased antioxidant activities, low cell toxicity, and remarkable effects on the TG content. Selected freeze-dried kimchi cabbage and onion significantly inhibited lipid accumulation and decreased the expression of obesity-associated messenger RNA (mRNA) and proteins, with freeze-dried kimchi cabbage being more efficient (P < 0.05). Discussion: The six kimchi ingredients showed differences in anti-obesity effects, and these effects may be related to antioxidant properties. Conclusion: Freeze-dried kimchi cabbage exhibited the most pronounced antioxidant and lipid-lowering effects among the six kimchi ingredients tested, highlighting the potential applications of kimchi in obesity-associated metabolic pathway research.