Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes) Polysaccharides Suppressed Adipogenesis and Stimulated Lipolysis in HPA-v and 3T3-L1 Adipocytes

Ganoderma lucidum polysaccharides (GLP) are one of the major bioactive components with many beneficial properties. In the present study we aimed to systematically evaluate the effects of GLP on lipid metabolism in human (HPA-v) and murine adipocytes (3T3-L1). Cell viability was assessed by MTT assay. Lipid accumulation in mature adipocytes were evaluated by ORO staining and quantified using the triglyceride (TG) assay. Lipolysis was investigated by measuring the free glycerol released in the cell culture medium after treatments. The mRNA and protein levels of key genes regulating lipid metabolism were determined by qRT-PCR and western blotting in HPA-v cells. ORO staining showed that GLP suppressed lipid accumulation similarly in both HPA-v and 3T3-L1 cells. TG assay confirmed that GLP significantly inhibited cell differentiation (p < 0.001). The lipolysis assay showed that GLP enhanced triglyceride hydrolysis in both adipocytes (p < 0.05). GLP stimulated AMPK phosphorylation, which promoted the phosphorylation of ACC1, its downstream target. qRT-PCR and western blotting showed that the genes encoding transcription factors for adipocyte differentiation (PPARγ, C/EBPα, and SREBPlc) and certain adipogenic genes (ACC1, PLIN1, and FASN) were downregulated (p < 0.05). The lipolytic gene HSL was upregulated and highly phosphorylated (activated) at mRNA and protein levels, respectively, upon GLP treatment. These results suggested that GLP possessed beneficial antiadipogenic effects and can potentially be developed into antiobesity products.