Antiobesity effect of ethanolic extract of Ramulus mori in differentiated 3T3-L1 adipocytes and high-fat diet-induced obese mice

Abstract

Ethnopharmacological relevance: The mulberry (Morus alba L.) is a plant that mainly grows in East Asian countries such as Korea and China and has been used as a folk remedy for improving inflammation, cancer, and diabetes. Romulus mori, the twig of Morus alba L., is known as "sangzhi" or "ppongnamugazhi" in Korea and used as a traditional medicine. Moreover, its effective compounds show some health benefits such as cholesterol reduction and attenuation of acute colitis. Aim of the study: As the number of obese people is increasing worldwide, the demand for diet drugs or products to treat obesity is also increasing. In this study, we investigated the antiobesity effect of the ethanolic extract of Romulus mori (ERM) using differentiated 3T3-L1 adipocytes and a high-fat diet (HFD)-induced obese mouse model. Methods: The expression levels of genes and proteins related to adipogenesis, lipogenesis, and lipolysis were analyzed by quantitative real-time PCR (qPCR) and western blot, respectively. Oil red O staining was carried out to determine the amount of neutral lipids deposited in the liver. Results: Compared with the ERM-untreated group, the ERM-treated groups exhibited reduced expression levels of genes involved in adipogenesis and lipogenesis in differentiated adipocytes and in HFD-induced obese mice, while the expression levels of genes involved in lipolysis increased. The administration of ERM to HFD-induced obese mice reduced the body weight, liver weight, and epididymal adipose tissue weight. Compared with the untreated HFD-induced obese mice, the ERM-treated mice exhibited decreased serum lipid levels. ERM treatment also reduced lipid accumulation in the liver, which was confirmed by oil red O staining. Conclusion: ERM has the potential to be an effective natural material for reducing obesity.