Blue honeysuckle rich in cyanidin-3-O-glucoside inhibited adipogenic differentiation by modulation of the adipogenesis pathway in 3T3-L1 adipocytes

Background: Blue honeysuckle (BH; Lonicera caerulea L.), which is a traditional medicinal plant, is known to be a rich source of anthocyanins and phenolic acids due to its strong antioxidant and anti-inflammatory activities. Its anti-obesity effects, which are a result of attenuating abnormal lipid and glucose metabolisms, have also been reported. Aim: The purpose of this study is to investigate the effect of BH on genes and proteins that are involved in the adipocyte differentiation using 3T3-L1 cells. Methods: The effects of the water extracts of the BH were examined on adipogenesis and lipolysis using a biochemical and molecular analysis of the 3T3-L1 cells. Results: Cyanidin-3-O-glucoside (C3G) from the BH extract was determined in order to contain 1.67 mg/g by the high-performance liquid chromatography analysis. The lipid accumulation in the adipocytes was reduced, which ranged from 58 to 26% in the BH (500 and 1,000 µg/mL) compared to the control group. The lipolysis that was measured by the glycerol content was not affected by the BH at 1,000 μg/mL. The BH downregulated the expression of the main transcription factors of the adipogenesis pathway, such as peroxisome proliferator-activated receptor γ, 1, 2, adipose differentiation-related protein, CCAAT/enhancer binding protein α, and acetyl CoA carboxylase, while increasing the expression of the Adenosine monophosphate (AMP)-activated protein kinase α. Conclusion: These findings suggest that the BH is a good source of C3G, and it could be effective in regard to inhibiting the adipogenesis as opposed to the lipolysis, which indicates the potential for natural anti-obesity ingredients.