Boeravinone B, a natural rotenoid, inhibits osteoclast differentiation through modulating NF-κB, MAPK and PI3K/Akt signaling pathways.

Osteoporosis is a major public health concern, which requires novel therapeutic strategies to prevent or mitigate bone loss. Natural compounds have attracted attention as potential therapeutic agents due to their safety and efficacy. In this study, we investigated the regulatory activities of boeravinone B (BOB), a natural rotenoid isolated from the medicinal plant Boerhavia diffusa, on the differentiation of osteoclasts and mesenchymal stem cells (MSCs), the two main cell components responsible for bone remodeling. We found that BOB inhibited osteoclast differentiation and function, as determined by TRAP staining and pit formation assay, with no significant cytotoxicity. Furthermore, our results showing that BOB ameliorates ovariectomyinduced bone loss demonstrated that BOB is also effective in vivo. BOB exerted its inhibitory effects on osteoclastogenesis by downregulating the RANKL/RANK signaling pathways, including NF-κB, MAPK, and PI3K/Akt, resulting in the suppression of osteoclast-specific gene expression. Further experiments revealed that, at least phenomenologically, BOB promotes osteoblast differentiation of bone marrow-derived MSCs but inhibits their differentiation into adipocytes. In conclusion, our study demonstrates that BOB inhibits osteoclastogenesis and promotes osteoblastogenesis in vitro by regulating various signaling pathways. These findings suggest that BOB has potential value as a novel therapeutic agent for the prevention and treatment of osteoporosis. [BMB Reports 2023; 56(10): 545-550].

Anti-cancer effects of the aqueous extract of Orostachys japonica A. Berger on 5-fluorouracil-resistant colorectal cancer via MAPK signalling pathways in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Orostachys japonica A. Berger, also known as Wa-song in Korea, has traditionally been used as a folk medicine, but the potential anti-cancer effects of aqueous extract of Orostachys japonica (OJe) have not yet been thoroughly investigated. AIM OF THE STUDY: To evaluate the anti-cancer effects of OJe, its possible mechanisms of action were investigated in 5-fluorouracil (5-FU) resistant SNU-C5/5-FUR colorectal cancer cells. MATERIALS AND METHODS: The functional compounds of OJe were identified with high performance liquid chromatography. The anti-cancer effects of OJe in SNU-C5/5-FUR cells were investigated by a cell viability assays, flow cytometry analysis, and a subcutaneous xenograft model employing BALB/c-nude mice. Possible signalling pathways were assayed with Western blotting. RESULTS: OJe (250 µg/ml) showed anti-cancer effects in SNU-C5/5-FUR cells, that were mediated via apoptosis as well as cell cycle arrest at the G0/G1 phase. Gallic acid and (-)-epicatechin, the major functional components of OJe, induced cell cycle arrest. OJe treatment (250 mg/kg, p.o.) produced a significant anti-proliferative effect in the xenograft model via decreased ß-catenin/GSK3ß and increased p27 expression. OJe treatment significantly activated ERK and p38 both in vitro and in vivo. CONCLUSIONS: These results suggest that OJe has anti-proliferative effects on 5-FU-resistant colorectal cancer cells via regulation of MAPK signalling pathways.

Assessment of the 4-week repeated-dose oral toxicity and genotoxicity of GHX02.

Herbal medicines are widely utilized for disease prevention and health promotion. GHX02 consists of mixtures including Gwaruin (Trichosanthes kirilowii), Haengin (Prunus armeniaca), Hwangryeon (Coptis japonica) and Hwangkeum (Scutellaria baicalensis). It has been purported to have therapeutic effectiveness in cases of severe bronchitis. Non-clinical safety testing comprised a single-dose oral toxicity study and a 28-day repeated-dose oral toxicity study with a 14-day recovery period, and genotoxicity was assessed by a bacterial reverse mutation test, in vitro chromosomal aberration test, in vivo mouse bone marrow micronucleus test and single cell gel electrophoresis assay (comet assay). In the single-dose oral toxicity study, the approximate lethal dosage is estimated to be higher than 5000 mg/kg in rats. Thus, the dosage levels were set at 0, 1250, 2500 and 5000 mg/kg/day in the 28-day repeated-dose oral toxicity study, and 10 male rats and 10 female rats/dose were administered GHX02. No clinical signs of toxicological significance were recorded in any animal during the dosing and the observation period in the single-dose study. The no-observed-adverse-effect level of GHX02 was 5000 mg/kg/day when administered orally for 28 days to male and female Sprague-Dawley rats. Despite increases in the frequencies of cells with numerical chromosomal aberration in the in vitro test, the increases were not considered relevant to the in vivo genetic risk. Except for the increase of in vitro numerical chromosomal aberration, clear negative results were obtained from other genetic toxicity studies.

Elevated extracellular calcium ions promote proliferation and migration of mesenchymal stem cells via increasing osteopontin expression.

Supplementation of mesenchymal stem cells (MSCs) at sites of bone resorption is required for bone homeostasis because of the non-proliferation and short lifespan properties of the osteoblasts. Calcium ions (Ca2+) are released from the bone surfaces during osteoclast-mediated bone resorption. However, how elevated extracellular Ca2+ concentrations would alter MSCs behavior in the proximal sites of bone resorption is largely unknown. In this study, we investigated the effect of extracellular Ca2+ on MSCs phenotype depending on Ca2+ concentrations. We found that the elevated extracellular Ca2+ promoted cell proliferation and matrix mineralization of MSCs. In addition, MSCs induced the expression and secretion of osteopontin (OPN), which enhanced MSCs migration under the elevated extracellular Ca2+ conditions. We developed in vitro osteoclast-mediated bone resorption conditions using mouse calvaria bone slices and demonstrated Ca2+ is released from bone resorption surfaces. We also showed that the MSCs phenotype, including cell proliferation and migration, changed when the cells were treated with a bone resorption-conditioned medium. These findings suggest that the dynamic changes in Ca2+ concentrations in the microenvironments of bone remodeling surfaces modulate MSCs phenotype and thereby contribute to bone regeneration.

Reactive transport of uranium with bacteria in fractured rock: model development and sensitivity analysis.

A numerical model for the reactive transport of uranium and bacteria in fractured rock was newly developed. The conceptual model consists of four phases (fracture, fracture surface, matrix pore, and matrix solid) and eight constituents (solutes in the fracture, on the fracture surface, on mobile bacteria, on immobile bacteria, in the rock matrix pores and on the rock matrix solids, and bacteria in the fracture and on the fracture surface). In addition to the kinetic sorption/desorption of uranium and bacteria, uranium reduction reaction accompanying with bacteria growth was considered in the reactive transport. The non-linear reactive transport equations were numerically solved using the symmetric sequential iterative scheme of the operator-splitting method. The transport and kinetic reaction modules in the developed model were separately verified, and the results were reasonably acceptable. From the sensitivity analysis, the uranium transport was generally more sensitive to the sorption rate rather than desorption rate of U(VI). Considering a uranium reduction reaction, bacteria could considerably retard the uranium transport no matter the uranium sorption/desorption rates. As the affinity of U(VI) onto the bacteria becomes higher than that onto a rock fracture surface, a biofilm effect, rather than a colloidal effect, of the bacteria becomes more influential on the uranium transport.

A new monoterpene glycoside from the roots of Paeonia lactiflora increases the differentiation of osteoblastic MC3T3-E1 cells.

A new monoterpene glycoside, 6'-O-beta-D-glucopyranosylalbiflorin (1), and four known compounds; albiflorin (2), 6'-O-benzoylalbiflorin (3), paeoniflorin (4) and benzoyl paeoniflorin (5), were isolated from the methanolic extract of the roots of Paeonia lactiflora Pall.. Their chemical structures were completely elucidated using a combination of 2D NMR techniques (COSY, HMQC and HMBC) and HRESI-MS analyses. To investigate the bioactivities of these compounds, their effects on the differentiation of osteoblastic MC3T3-E1 cells were tested. Compound 1 (0.01-10 microM) significantly increased the alkaline phosphatase activity and nodules mineralization of MC3T3-E1 cells compared to those of the control (P<0.05). These results suggest that newly isolated compound 1 has a direct stimulatory effect on bone formation in vitro and may contribute to the prevention for osteoporosis.

Lignans with inhibitory activity against NFAT transcription from Schisandra chinensis.

Seven lignans from Schisandra chinensis were investigated for their inhibitory activity on NFAT transcription. Both gomisin N (IC 50 : 1.33 +/- 0.05 microM) and schisandrol A (IC 50 : 1.34 +/- 0.05 microM) showed higher activity than gomisin E (IC 50 : 4.73 +/- 0.09 microM), schisandrin A (IC 50 : 7.23 +/- 0.21 microM), schisandrin C (IC 50 : 7.54 +/- 0.22 microM), benzoylisogomisin O (IC 50 : 11.06 +/- 1.02 microM) and schisandrol B (IC 50 : 16.37 +/- 1.00 microM).