Osteoporosis is an abnormal bone remodeling condition characterized by decreased bone density, which leads to high risks of fracture. Previous study has demonstrated that Lycii Radicis Cortex (LRC) extract inhibits bone loss in ovariectomized (OVX) mice by enhancing osteoblast differentiation. A bioactive compound, kukoamine B (KB), was identified from fractionation of an LRC extract as a candidate component responsible for an anti-osteoporotic effect. This study investigated the anti-osteoporotic effects of KB using in vitro and in vivo osteoporosis models. KB treatment significantly increased the osteoblastic differentiation and mineralized nodule formation of osteoblastic MC3T3-E1 cells, while it significantly decreased the osteoclast differentiation of primary-cultured monocytes derived from mouse bone marrow. The effects of KB on osteoblastic and osteoclastic differentiations under more physiological conditions were also examined. In the co-culture of MC3T3-E1 cells and monocytes, KB promoted osteoblast differentiation but did not affect osteoclast differentiation. In vivo experiments revealed that KB significantly inhibited OVX-induced bone mineral density loss and restored the impaired bone structural properties in osteoporosis model mice. These results suggest that KB may be a potential therapeutic candidate for the treatment of osteoporosis.

Obesity is caused by an excess storage of body fat, resulting from a chronic imbalance between energy intake and expenditure. Gentiana lutea L. (GL) root has been reported to reduce lipid accumulation in the aortic wall of diabetic rats. Here, we performed fractionation and isolation of the bioactive constituent(s) that may be responsible for the antiadipogenic effects of the GL root extract. A single compound, loganic acid, was identified as a candidate component in the 30% ethanol extract of GL. Loganic acid treatment significantly decreased the adipocyte differentiation of 3T3-L1 preadipocytes in a dose-dependent manner. The expression of key adipogenesis-related genes such as adiponectin (Adipoq), peroxisome proliferator-activated receptor gamma (Pparg), lipoprotein lipase (Lpl), perilipin1 (Plin1), fatty acid binding protein 4 (Fabp4), glucose transporter type 4 (Slc2a4), CCAAT/enhancer-binding protein alpha (Cebpa), and tumor necrosis factor-alpha (Tnf) were significantly reduced following treatment with loganic acid. In vivo experiments in an ovariectomy-induced obesity mouse model showed that loganic acid (oral administration with 10 and 50 mg/kg/day) significantly inhibited body weight gain, total fat increase, fatty hepatocyte deposition in the liver, and adipocyte enlargement in the abdominal visceral fat tissues. These results suggest that loganic acid in the GL root extract has antiadipogenic effects in vitro and in vivo. Loganic acid may be beneficial for the prevention and treatment of obesity, particularly in menopausal obese women.

Gentiana rigescens is a rich source of iridoids and is commonly used as a folk medicine for treatment of hepatitis and cholecystitis for over 1000 years. A rapid ultrafast liquid chromatography-ultraviolet method was developed for simultaneous determination of four major iridoid glycosides in G. rigescens. Response surface methodology based on the Box-Behnken design was applied to optimize the extraction conditions of iridoid glycosides. Using the Shim-Pack XR-ODS III, four iridoid glycosides were efficiently separated with an acetonitrile:0.1% formic acid aqueous solution gradient at a flow rate of 0.25 mL/min for 8 minutes. All the regression equations revealed a good linear relationship (R2 > 0.9995). The intraday and interday variations were <1.95%. The recoveries ranged from 99.7% to 103.2%. The optimal extraction conditions were as follows: methanol concentration, 82%; the ratio of liquid to solid material, 68:1 (mL/g); and extraction time, 32 minutes. The yield of the four iridoid glycosides under the optimal process was found to be 63.08 mg/g, which was consistent with the predicted yield. In addition, the total content of 50 cultivated samples from Lincang, Yunnan, China, was within the range of 33.6-113.26 mg/g, which provides a more reasonable foundation for utilization of G. rigescens.