Various studies have demonstrated that overexpression of cathepsin K (Cat-K) causes excessive bone loss, which ultimately leads to a variety of bone diseases including osteoporosis. Therefore, inhibition of Cat-K signifies a potential therapeutic target in osteoporosis treatment. Ginsenoside Rg3 is one of the most promising compound of Panax ginseng Meyer (P. ginseng) with numerous biological activities. Thus, in recent study the inhibitory effect of Rg3 isolated from P. ginseng was investigated in order to impede the osteoclast activity by an in silico approach followed by in vitro study validation using RAW264.7 cells through the investigation of different biological activity prediction such as absorption distribution metabolism and excretion (ADMET) properties against Cat-K protein. The docking results of our study showed that Rg3 is a non-toxic compound and may act as a drug-like molecule. Additionally, the molecular interaction of Rg3 with the active residues of Cat-K markedly describes its inhibitory effects on osteoclastogenesis. Findings of the present study exhibited that Rg3 significantly reduced receptor activator of nuclear factor kappa B ligand (RANKL)-induced tartrate-resistant acid phosphatase (TRAP) activity, pit formation (actin rings), and TRAP-positive multinucleated cells development in RAW264.7 cells. Furthermore, Rg3 dose-dependently reduced the mRNA expression levels of osteoclast-specific markers such as RANK, TRAP, and Cat-K induced by RANKL through the down regulation of p38, extracellular signal-regulated kinase, and c-Jun N-terminal kinase (JNK) pathways. In conclusion, in silico docking study and in vitro validation together suggested that Rg3 inhibits osteoclastogenesis and reduces bone resorption through the inhibition of Cat-K. Therefore, Rg3 might be a useful therapeutic agent for the treatment of osteoporosis and proper bone formation. Copyright © 2015 John Wiley & Sons, Ltd.

In previous studies compound K (CK), an active metabolite ginsenoside from Panax ginseng, was shown to exhibit anti-cancer activity. However, the mechanism of CK through the EGFR/H-Ras pathway in cancer cells has not been reported so far. Therefore, we focused on the effect of CK as an EGFR and H-Ras inhibitor by in silico and in vitro studies using A549 cells. The biological activity prediction shows that CK exhibits chemopreventive, anticarcinogenic and antimetastatic activity. Also, using molecular docking studies it has been shown that CK exhibits a strong binding energy with EGFR and H-Ras than Erlotinib. CK inhibits cell viability, decreases cell migration, induces apoptosis and strongly decreases gene expression of EGFR and H-Ras genes in vitro. This finding suggests that the EGFR pathway is involved in the anti-cancer activity of CK of EGF-enhanced A549 lung cancer cell line.

Background:Diabetes mellitus is a metabolic syndrome exaggerated by stress conditions. Endoplasmic reticulum stress (ERS) impairs the insulin signaling pathway making the diabetic conditions worsen. Pharmacological agents are supplied externally to overcome this malfunction. Ginsenosides from Panax ginseng C.A Meyer possesses many pharmacological properties and are used for the treatment of diabetes.Objective:To investigate the effects of the Rk1 +Rg5 complex on the amelioration of insulin resistance in 3T3-L1 cells under endoplasmic reticulum stress conditions.Materials and Methods:Heat-processed ginseng extracts are found to contain many pharmacologically active ginsenosides. Among them Rk1 +Rg5 is found to be present in higher concentrations than the other minor ginsenosides. The Rk1 +Rg5 complex was tested for its effect in the 3T3-L1 insulin-resistant model and subjected to the MTT assay, glucose oxidase assay and gene expression studies using RT-PCR and real-time PCR under endoplasmic reticulum stress conditions.Results:Rk1 +Rg5 treatment is found to increase the glucose uptake into the cells when compared to that of a positive control (tunicamycin treatment group, TM). Further we have analyzed the role at gene expression level. The Rk1 +Rg5 complex was found to show an effect on the IGF 2R receptor, CHOP-10, and C/EBP gene at a particular treated concentration (50 μM). Moreover, stress condition (about 50% decreases) was overcome by the ginsenoside treatments at 50 μM.Conclusion:The present results showed that under endoplasmic reticulum stress conditions Rk1 +Rg5 complex exhibits a potential protective role in insulin-resistant 3T3-L1 cells.

Osteoporosis is a widespread musculoskeletal deformity that affects thousands of older people every year, leading to bone abnormalities and ultimately increasing the risk of bone fractures in both genders. It is considered a lethal disease causing death in thousands of people at the late stage of life. Dendropanax morbifera Leveille is a subtropical broad-leaved prevalent species in Korea. Extracts of the leaves, stems, roots, and seeds of D. morbifera have been used in traditional medicine for the treatment of numerous diseases such as diabetes, atherogenesis, skin disorders, and headaches. However, the anti-osteoporosis effects of D. morbifera have not been examined. The primary objectives of this study were to elucidate the anti-osteoporosis effect of D. morbifera extract through an in vitro study using pre-osteoblastic MC3T3-E1 cells. We found that D. morbifera strongly increased the expression of bone metabolic markers such as alkaline phosphatase (ALP) activity, type I collagen (Col-I) level, and mineralization. Additionally, D. morbifera extract also upregulated the mRNA expression levels of osteogenic genes including ALP, osteocalcin (OCN), osterix (Osx), and runt-related transcription factor 2 (Runx2) in MC3T3-E1 cells via upregulation of bone morphogenetic protein 2 (BMP-2)/p38 MAPK/JNK and Smad1/5/8 signaling pathways. Moreover, addition of D. morbifera significantly suppressed the inhibitory effect of SB203580 (p38 inhibitor). In conclusion, the current study demonstrated that D. morbifera extract significantly increased osteoblast differentiation and mineralization in MC3T3-E1 cells by regulating BMP-2/p38/JNK and Smad1/5/8. Our study might be helpful in the discovery and development of new anti-osteoporosis therapeutic agents.

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