Mulberry (Morus alba L.) ethanol extract attenuates lipid metabolic disturbance and adipokine imbalance in high-fat fed rats

BACKGROUND/OBJECTIVES: An imbalanced adipokine profile in obesity increases the susceptibility to obesity-related cardiometabolic alterations, including type 2 diabetes, hypertension, dyslipidemia, and non-alcoholic fatty liver disease. The mulberry plant has been reported to have health benefits, such as hypolipidemic and hepatoprotective effects. This study examined the effects of a mulberry (Morus alba L.) fruit ethanol extract (MBEE) on dyslipidemia, liver steatosis, and adipokine imbalance in response to a high-fat diet. MATERIALS/METHODS: Male Sprague-Dawley rats were assigned to one of 4 groups containing 6 rats each and fed either a control diet (CON), a high-fat diet (HFD), or a high-fat diet with MBEE of 150 mg/kg/day (LMB) or 300 mg/kg/day (HMB). The triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activities were measured spectrophotometrically. The leptin, adiponectin, and plasminogen activator inhibitor-1 (PAI-1) levels were determined by an enzyme-linked immunosorbent assay. RESULTS: The plasma TG levels were similar in the 4 groups. Plasma cholesterol and low-density lipoprotein cholesterol (LDL-C) levels and TC/HDL-C ratio increased in the HFD group compared with the CON group, whereas those values decreased in the LMB group (P < 0.05), indicating that MBEE had a plasma lipid-lowering effect. HDL-C decreased in the HFD group, but MBEE did not affect the HDL-C level. The HFD rats significantly increased hepatic TG and cholesterol levels and plasma ALT and AST activities compared to the CON group. The hepatic TG level and ALT and AST activities were reduced markedly by the MBEE treatment. The HFD group showed a higher PAI-1 level, whereas MBEE treatment, especially in the HMB group, significantly reduced leptin level, and leptin/adiponectin and PAI-1/adiponectin ratios. These findings suggest that MBEE altered the imbalance between the pro- and anti-inflammatory adipokines to a more anti-inflammatory state. CONCLUSIONS: MBEE could protect against abnormal lipid metabolism and hepatic steatosis induced by a high-fat diet, lowering plasma cholesterol, LDL-C and TC/HDL-C, and hepatic TG. These findings are associated with the regulating effect of MBEE on the leptin/adiponectin and PAI-1/adiponectin ratios.