Agrimonia pilosa Ledeb. aqueous extract improves impaired glucose tolerance in high-fat diet-fed rats by decreasing the inflammatory response

BACKGROUND: Agrimonia pilosa Ledeb. is a medicinal plant with physiological activities such as anti-cancer, antioxidant, anti-inflammatory activities and in vitro anti-diabetic activity. However, the effects of aqueous extracts from A. pilosa on insulin-resistant rats have not yet been examined. We investigated the effects of aqueous extract from A. pilosa on impaired glucose metabolism induced by a high-fat diet in rats. METHODS: Male Sprague-Dawley rats were assigned to the following groups: normal-fat diet (NF, n = 9); high-fat diet (HF, n = 9); high-fat diet with 0.1% A. pilosa aqueous extract (HFA, n = 10). Experimental diets were administered for 16 weeks. At the end of the treatment, liver and fat tissues were isolated, and serum was collected for biochemical analysis. RESULTS: The HF group rats had a significantly higher liver weight than the NF group rats did, and increased hepatic lipid accumulation (p < 0.05); however, supplementation with A. pilosa decreased liver weight. Blood glucose levels in the HFA group were lower than levels measured in the HF group 30, 60, and 120 min after glucose administration (p < 0.05). In addition, dietary A. pilosa supplementation decreased tumor necrosis factor α and interleukin 6 levels, while increasing serum adiponectin concentrations (p < 0.05 vs. the HF group). These effects were accompanied by reduced hepatic and adipose tissue expression of inflammation-related genes such as Tnf and Il1b (p < 0.05). CONCLUSIONS: Our findings indicate that A. pilosa aqueous extract can ameliorate insulin resistance in high-fat diet-fed rats by decreasing the inflammatory response. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12906-017-1949-z) contains supplementary material, which is available to authorized users.