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Abstract Background Chrysosplenetin is an O-methylated flavonol compound isolated from the plant Chamomilla recutita and Laggera pterodonta. The aim of our research is to evaluate the function of Chrysosplenetin on osteogenesis of human-derived bone marrow stromal cells (hBMSCs) and inhibition of estrogen deficiency-induced osteoporosis via the Wnt/β-catenin signaling pathway. Method hBMSCs are cultured and treated by Chrysosplenetin in the absence or presence of Wnt inhibitor dickkopf-related protein 1 (DKK1) or bone morphogenetic protein 2 (BMP2) antagonist Noggin. RT-qPCR is taken to identify the genetic expression of target genes of Wnt/β-catenin pathway and osteoblast-specific markers. The situation of β-catenin is measured by western blot and immunofluorescence staining. An ovariectomized (OVX) mouse model is set up to detect the bone loss suppression by injecting Chrysosplenetin. Micro-CT and histological assay are performed to evaluate the protection of bone matrix and osteoblast number. Serum markers related with osteogenesis are detected by ELISA. Results In the present study, it is found that Chrysosplenetin time-dependently promoted proliferation and osteoblastogenesis of hBMSCs reaching its maximal effects at a concentration of 10 μM. The expressions of target genes of Wnt/β-catenin pathway and osteoblast-specific marker genes are enhanced by Chrysosplenetin treatment. Furthermore, the phosphorylation of β-catenin is decreased, and nuclear translocation of β-catenin is promoted by Chrysosplenetin. Osteogenesis effects mentioned above are founded to be blocked by DKK1 or BMP2 antagonist Noggin. In vivo study reveals that Chrysosplenetin prevents estrogen deficiency-induced bone loss in OVX mice detected by Micro-CT, histological analysis, and ELISA. Conclusions Our study demonstrates that Chrysosplenetin improves osteoblastogenesis of hBMSCs and osteogenesis in estrogen deficiency-induced bone loss by regulating Wnt/β-catenin pathway.

Background: Artemisinin (ART) is an efficacious and safe anti-malarial drugs but has low oral bioavailability and auto-induction profiles during multiple dosing. The pharmacokinetic disadvantages have been found to partially depend on the induction of cytochrome P-450 enzymes by ART and resulted in the therapeutic failure due to insufficient drug levels. The present study, therefore, investigated the impacts of chrysosplenetin (CHR), a polymethoxylated flavonoid from Artemisia annua, on the pharmacokinetics and the anti-malarial efficacy of ART against Plasmodium berghei. The inhibition of CHR on enzymatic activity of CYP1A2, CYP2A, CYP2C19, CYP2D6, CYP2E1, and CYP3A in rat liver microsome was also investigated. IC50, Km, Ki, and inhibitory type of CHR were respectively calculated. Methods: Twenty rats were randomly divided into four groups and received three-day oral doses of ART in absence or presence of CHR (in ratio of 1:0, 1:1, 1:2, and 1:4, respectively). Plasma samples were separately harvested for ART pharmacokinetics analysis using a valid liquid chromatography tandem mass spectrometric (LC-MS/MS) method. Female Kunming mice were inoculated by P. berghei K173 strain and pre-exposed to three-day oral administration of ART with or without CHR as pharmacokinetics protocol. Giemsa staining method was applied to calculate percent parasitaemia (%) and inhibition (%). In vitro rat liver microsomal model was employed to elucidate the inhibitory effect of CHR on CYP1A2, CYP2A, CYP2C19, CYP2D6, CYP2E1, and CYP3A. Results: The AUC0-t, Cmax, and t1/2 of ART increased significantly (P < 0.05 or P < 0.01) as well as declined CLz (P < 0.05 or P < 0.01) after three-day oral doses of ART in presence of CHR (1:2) when compared with ART alone. Also, parasitaemia (%) remarkably attenuated 1.59 folds with 1.63-fold augmented inhibition (%) when the ratio between ART and CHR reached 1:2. CHR itself had no anti-malarial efficacy (P > 0.05). CHR inhibited in vitro activity of CYP1A2 and CYP2C19 (P < 0.01, IC50 = 4.61 and 6.23 μM) in a concentration-response manner. The inhibition did not emerge on CYP2E1 and CYP3A until the CHR concentration exceeded 4.0 μM (P < 0.01, IC50 = 28.17 and 3.38 μM). CHR has no impact on CYP 2A and CYP2D6 (P > 0.05). The inhibition types of CHR on CYP1A2 and CYP3A belonged to noncompetitive and uncompetitive, respectively. Conclusions: Co-administration of ART with CHR in ratio of 1:2 achieved a synergic anti-malarial effect partly because of the noncompetitive or uncompetitive inhibition of CHR of drug-metabolism enzymes, especially CYP3A which is closely related to the auto-induction of ART. [ABSTRACT FROM AUTHOR]

Background: Chrysosplenetin is an O-methylated flavonol compound isolated from the plant Chamomilla recutita and Laggera pterodonta. The aim of our research is to evaluate the function of Chrysosplenetin on osteogenesis of human-derived bone marrow stromal cells (hBMSCs) and inhibition of estrogen deficiency-induced osteoporosis via the Wnt/β-catenin signaling pathway. Method: hBMSCs are cultured and treated by Chrysosplenetin in the absence or presence of Wnt inhibitor dickkopf-related protein 1 (DKK1) or bone morphogenetic protein 2 (BMP2) antagonist Noggin. RT-qPCR is taken to identify the genetic expression of target genes of Wnt/β-catenin pathway and osteoblast-specific markers. The situation of β-catenin is measured by western blot and immunofluorescence staining. An ovariectomized (OVX) mouse model is set up to detect the bone loss suppression by injecting Chrysosplenetin. Micro-CT and histological assay are performed to evaluate the protection of bone matrix and osteoblast number. Serum markers related with osteogenesis are detected by ELISA. Results: In the present study, it is found that Chrysosplenetin time-dependently promoted proliferation and osteoblastogenesis of hBMSCs reaching its maximal effects at a concentration of 10 μM. The expressions of target genes of Wnt/β-catenin pathway and osteoblast-specific marker genes are enhanced by Chrysosplenetin treatment. Furthermore, the phosphorylation of β-catenin is decreased, and nuclear translocation of β-catenin is promoted by Chrysosplenetin. Osteogenesis effects mentioned above are founded to be blocked by DKK1 or BMP2 antagonist Noggin. In vivo study reveals that Chrysosplenetin prevents estrogen deficiency-induced bone loss in OVX mice detected by Micro-CT, histological analysis, and ELISA. Conclusions: Our study demonstrates that Chrysosplenetin improves osteoblastogenesis of hBMSCs and osteogenesis in estrogen deficiency-induced bone loss by regulating Wnt/β-catenin pathway. [ABSTRACT FROM AUTHOR]