Standardized Ethanol Extract of Curcuma longa L. Fermented by Aspergillus oryzae Promotes Lipolysis via Activation of cAMP-Dependent PKA in 3T3-L1 Adipocytes

Abstract

We investigated the effect of standardized ethanol extract from Curcuma longa L. fermented by Aspergillus oryzae (FTE) on lipid accumulation and lipolysis using 3T3-L1 adipocytes. Treatment with FTE at 100 μg/mL significantly reduced lipid accumulation by 43% as quantified by Oil Red O dye and microscopic observation. Intracellular triglyceride content was also lowered by 60%. To determine the effects of FTE on lipolysis, levels of glycerol release and mRNA expression of lipases were measured. Incubation of 3T3-L1 adipocytes with 60 and 100 μg/mL FTE dramatically elevated levels of free glycerol released into the medium by 58 and 77%, respectively. Likewise, treatment of mature adipocytes with FTE significantly increased cAMP level by reduction of phosphodiestersae-3B. Subsequently, FTE clearly increased hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) mRNA levels and decreased perilipin mRNA level via cAMP-dependent protein kinase A (PKA), resulting in lipolysis. Practical Applications Turmeric (the common name for Curcuma longa L.) is an Indian spice derived from rhizomes of the plant Curcuma longa, a perennial member of the Zingiberaceae family cultivated in India and other parts of Southeast Asia. Turmeric has traditionally been used for the treatment of inflammation, menstrual disorders, dyspepsia, vomiting and cancer. In this study, FTE suppressed 3T3-L1 preadipocyte differentiation and promoted lipolysis via upregulation of mRNA levels of HSL and ATGL by PKA phosphorylation. Our results suggested that FTE could be a candidate for antiobesity treatment through reduction of lipid accumulation and stimulation of lipolysis.