A transcriptomic analysis of black cohosh: Actein alters cholesterol biosynthesis pathways and synergizes with simvastatin

Role and mechanism of Actein on condylar bone metabolism in APOE deletion-induced osteoporotic mice

AIMS

To investigate the effects of Actein from Cimicifugae Rhizoma on condylar bone and cartilage in APOE deletion-induced osteoporotic mice, and to preliminarily explore the underlying mechanism.

METHODS

Sixty 8-week-old female mice were used, which underwent APOE-/- and ovariectomy procedures, followed by oral administration of Actein (15 mg/kg) and Atorvastatin Calcium (AC, 3 mg/kg) for eight weeks. Body weight, uterine weight, and systemic indexes related to bone metabolism and lipid metabolism were assessed in each group. Changes in condylar bone histomorphometric parameters were evaluated using Micro-CT. Morphological changes in the condyle were observed with Hematoxylin-Eosin (H&E), Safranin O/Fast Green, and Alcian Blue Hematoxylin/Orange G (ABH/OG) staining, with OARSI pathology scoring performed. Sirius red staining and immunofluorescence were used to determine the expression levels of Collagen I (Col I) and Collagen III (Col III) in bone matrix, and Col II in cartilage matrix. Immunohistochemistry assessed the relative expression levels of ALP and proteins associated with the Wnt/β-catenin/RUNX2 signaling pathway.

RESULTS

APOE-/- exacerbates ovariectomy -induced osteoporosis (OP) in condylar of mice. Actein and AC significantly reversed OP, improved bone mineral density (BMD), increased bone microarchitecture, and restored abnormal calcium and phosphorus metabolism in the blood and urine. Morphologically, APOE-/- and ovariectomy reduced condylar cartilage thickness, disrupted chondrocyte arrangement, chondrocyte cleavage, and clustered aggregation, resembling osteoarthritis (OA)-like changes. Actein and AC partially restored the disrupted chondrocyte arrangement, smoothed chondrocyte cleavage, and up-regulated the levels of chondrocyte matrix (Col II, aggrecan) and bone matrix (Col III, ALP). Actein reversed the OA process, potentially through the Wnt/β-catenin/RUNX2 signaling pathway.

CONCLUSION

APOE-/- and ovariectomy induced OP, leading to OA-like lesions in condylar of mice. Actein promoted cartilage repair and trabecular bone recovery by increasing extracellular matrix synthesis (Col II, Col III, aggrecan), reversing the OA process, possibly through the Wnt/β-catenin/RUNX2 signaling pathway.

Actein Inhibits Tumor Growth and Metastasis in HER2-Positive Breast Tumor Bearing Mice via Suppressing AKT/mTOR and Ras/Raf/MAPK Signaling Pathways

HER2-positive breast cancer accounts for 15–20% in breast cancer and 50% of the metastatic HER2-positive breast cancer patients died of central nervous system progression. The present study investigated the effects of actein (a natural cycloartane triterpene) on cells adhesion, migration, proliferation and matrix degradation, and its underlying mechanism in HER2-positive breast cancer cells. The in vivo effect of actein on tumor growth and metastasis in MDA-MB-361 tumor-bearing mice as well as the anti-brain metastasis in tail vein injection mice model were also investigated. Our results showed that actein inhibited HER2-positive breast cancer cells viability, proliferation and migration. Actein also induced MDA-MB-361 cells G1 phase arrest and inhibited the expressions of cyclins and cyclin-dependent kinases. For intracellular mechanisms, actein inhibited the expressions of molecules in AKT/mTOR and Ras/Raf/MAPK signaling pathways. Furthermore, actein (15 mg/kg) was shown to exhibit anti-tumor and anti-metastatic activities in MDA-MB-361 breast tumor-bearing mice, and reduced brain metastasis in tail vein injection mice model. All these findings strongly suggested that actein is a potential anti-metastatic agent for HER2-positive breast cancer.