Osteoporosis is a common disease caused by an imbalance of processes between bone resorption by osteoclasts and bone formation by osteoblasts in postmenopausal women. The roots of Gentiana lutea L. (GL) are reported to have beneficial effects on various human diseases related to liver functions and gastrointestinal motility, as well as on arthritis. Here, we fractionated and isolated bioactive constituent(s) responsible for anti-osteoporotic effects of GL root extract. A single phytochemical compound, loganic acid, was identified as a candidate osteoprotective agent. Its anti-osteoporotic effects were examined in vitro and in vivo. Treatment with loganic acid significantly increased osteoblastic differentiation in preosteoblast MC3T3-E1 cells by promoting alkaline phosphatase activity and increasing mRNA expression levels of bone metabolic markers such as Alpl, Bglap, and Sp7. However, loganic acid inhibited osteoclast differentiation of primary-cultured monocytes derived from mouse bone marrow. For in vivo experiments, the effect of loganic acid on ovariectomized (OVX) mice was examined for 12 weeks. Loganic acid prevented OVX-induced bone mineral density loss and improved bone structural properties in osteoporotic model mice. These results suggest that loganic acid may be a potential therapeutic candidate for treatment of osteoporosis.

Medicinal plants have been used worldwide as primary alternative healthcare supplements. Cornus officinalis (CO) and Ribes fasciculatum (RF) are traditional medicinal plants applied in East Asia to treat human diseases such as hepatitis, osteoporosis, oxidative stress and allergy. The aim of this study was to examine the anti-obesity effect of CO and RF on preadipocyte 3T3-L1 cells in vitro and high-fat diet (HFD)-induced obesity mice in vivo. Combination treatment of CO and RF in differentiated 3T3-L1 cells inhibited adipocyte differentiation through downregulation of adipogenesis-associated genes such as CCAAT/enhancer-binding protein alpha (Cebpa), fatty acid binding protein 4 (Fabp4), peroxisome proliferator-activated receptor gamma (Pparg) and sterol regulatory element binding protein (Srebp1). In vivo animal models showed that a mixture of CO and RF inhibited HFD-induced weight gain, resulting in decreased abdominal visceral fat tissues and fatty hepatocyte deposition. In addition, CO+RF treatment decreased HFD-induced adipogenesis-associated genes in abdominal white fat tissue. These results suggest that administration of a CO and RF mixture prevented adipocyte differentiation and lipid accumulation in preadipocyte cells and HFD-induced body weight in obesity mice. Therefore, combined therapy of CO and RF may be a protective therapeutic agent against obesity.

Osteoporosis is a porous bone disease caused by bone density loss, which increases the risk of fractures. Cornus officinalis (CO) and Achyranthes japonica (AJ) have been used as traditional herbal medicine for various disorders in East Asia. Although the anti-osteoporotic effects of single extract of CO and AJ have already been reported, the synergistic effect of a combined mixture has not been studied. In this study, we investigated the effects of a CO and AJ herbal mixture on osteoporosis in in vitro and in vivo models. The results demonstrate that treatment with the CO and AJ mixture significantly promoted osteoblast differentiation of MC3T3-E1 mouse preosteoblasts through the upregulation of osteoblastic differentiation-associated genes such as alkaline phosphatase (Alpl), runt-related transcription factor 2 (Runx2), and bone gamma-carboxyglutamic acid-containing protein (Bglap), while the mixture significantly inhibited differentiation of osteoclasts isolated from primary-cultured mouse monocytes. In addition, oral administration of CO and AJ mixture significantly prevented bone mineral density loss and trabecular bone structures in an ovariectomy-induced osteoporotic mouse model. These results suggest that the combination treatment of CO and AJ mixture might be a beneficial therapy for osteoporosis.

Arthritis is a common inflammatory disease that causes pain, stiffness, and joint swelling. Here, we investigated the ameliorative effects of loganin on arthritis in vitro and in vivo. A single bioactive compound was fractionated and isolated from Cornus officinalis (CO) extract to screen for anti-arthritic effects. A single component, loganin, was identified as a candidate. The CO extract and loganin inhibited the expression of factors associated with cartilage degradation, such as cyclooxygenase-2 (COX-2), matrix metalloproteinase 3 (MMP-3), and matrix metalloproteinase 13 (MMP-13), in interukin-1 beta (IL-1β)-induced chondrocyte inflammation. In addition, prostaglandin and collagenase levels were reduced following treatment of IL-1β-induced chondrocytes with loganin. In the destabilization of the medial meniscus (DMM)-induced mouse model, loganin administration attenuated cartilage degeneration by inhibiting COX-2, MMP-3, and MMP-13. Transverse micro-CT images revealed that loganin reduced DMM-induced osteophyte formation. These results indicate that loganin has protective effects in DMM-induced mice.

Obesity is characterized by the excessive accumulation of mature adipocytes that store surplus energy in the form of lipids. In this study, we investigated the inhibitory effects of loganin on adipogenesis in mouse preadipocyte 3T3-L1 cells and primary cultured adipose-derived stem cells (ADSCs) in vitro and in mice with ovariectomy (OVX)- and high-fat diet (HFD)-induced obesity in vivo. For an in vitro study, loganin was co-incubated during adipogenesis in both 3T3-L1 cells and ADSCs, lipid droplets were evaluated by oil red O staining, and adipogenesis-related factors were assessed by qRT-PCR. For in vivo studies, mouse models of OVX- and HFD-induced obesity were orally administered with loganin, body weight was measured, and hepatic steatosis and development of excessive fat were evaluated by histological analysis. Loganin treatment reduced adipocyte differentiation by accumulating lipid droplets through the downregulation of adipogenesis-related factors, including peroxisome proliferator-activated receptor γ (Pparg), CCAAT/enhancer-binding protein α (Cebpa), perilipin 2 (Plin2), fatty acid synthase (Fasn), and sterol regulatory element binding transcription protein 1 (Srebp1). Loganin administration prevented weight gain in mouse models of obesity induced by OVX and HFD. Further, loganin inhibited metabolic abnormalities, such as hepatic steatosis and adipocyte enlargement, and increased the serum levels of leptin and insulin in both OVX- and HFD-induced obesity models. These results suggest that loganin is a potential candidate for preventing and treating obesity.

Medicinal plants are widely used as supplements for the treatment of various diseases because of their few side-effects. Here, we examined the anti-obesity effects of a mixture extract of Cornus officinalis and Ribes fasciculatum (CR) in high-fat diet (HFD)-induced obese male mice. Four week old male C57BL/6J mice were fed a normal diet (ND) or 60% high-fat diet (HFD) with different concentrations of CR extracts (75, 150, and 300 mg/kg/day) by oral administration for 12 weeks. CR extract administration prevented HFD-induced weight gain, hepatic steatosis, and adipocyte enlargement through the downregulation of adipogenesis-associated genes in obese male mice. In addition, CR administration improved the impaired glucose metabolism, insulin action, biochemical obesity parameters, and metabolic profiles in HFD-induced male mice. Consequently, the CR extract exhibited beneficial effects on HFD-induced systemic metabolic challenges. Taken together, our findings suggest that CR extract may be a potent therapeutic supplement for the treatment and prevention of obesity.