Water‐Soluble Pu‐Erh Tea Extracts at Reasonable Oral Doses Down‐Regulate the Expression of Genes Involved in Fat Synthesis and Prevent Weight Gain in High‐Fat Diet‐Fed Mice

Pu-erh tea attenuates obesity and lipid metabolism by inhibiting pancreatic lipase, but prior studies used doses much higher than typical human consumption, which raised concerns about renal toxicity. This study aimed to investigate the effects of human drinkable doses of Pu-erh tea extract (PTE) on obesity and lipid metabolism. High-fat diet (HFD)-fed male C57BL/6J mice were orally administered distilled water (HFD group), 107.5 mg/kg PTE (High group, human equivalent: 1200 mL), or half of the High group's dose (Low group, human equivalent: 600 mL) per day. Hepatic and visceral fat accumulation, and body weight normalized by caloric consumption were reduced in the High group compared to the HFD group. Additionally, PTE decreased plasma triglyceride (TG) and the gene expression of fat synthesis genes in the liver, concomitant with a reduction in histologically observed hepatic fat deposits. Furthermore, mRNA expression levels related to TG synthesis in adipocytes, decreased in response to PTE treatment. PTE administration, at a human drinkable dose, inhibited fat accumulation. This might be related to the decreased expressions of these genes in adipocytes or the liver involved in these functions, which would presumably contribute to the prevention of weight gain.