Obesity is a global public health issue, closely linked to cardiovascular disease and type 2 diabetes. Pharmacological interventions for weight loss are one option for treating obesity
however, these drugs often come with side effects or limited efficacy, highlighting the need for new therapies. Marine algae offer a promising source of biologically active compounds for human health, including antidiabetic, anti-inflammatory, and anti-obesity properties. Sulfated galactan isolated from the red marine algae Acanthophora muscoides (SGAM) has demonstrated diverse biological activities including anti-inflammatory activity in vivo and in vitro studies. However, its potential impact on adipogenesis remains unexplored. This study evaluated the effect of SGAM on adipogenesis in 3T3-L1 cells using Oil Red O staining and analyzed the protein expression of key transcription factors associated with adipogenesis. SGAM (25-100 μg/mL) was found to reduce intracellular lipid accumulation in adipocytes without compromising cell viability. Furthermore, our findings suggest that SGAM significantly inhibits adipocyte differentiation by downregulating the expression of key adipogenesis-related transcription factors, including C/EBPβ, C/EBPδ, C/EBPα, and PPARγ. Additionally, SGAM reduced the protein expression of SREBP-1 and promoted the activation of AMPK. In conclusion, SGAM inhibits adipogenesis by negatively modulating the expression of the main adipogenic transcription factors and activating AMPK.