Jia-Zhong Cai

Cajanolactone A (CLA) is a stilbenoid discovered by us from Cajanus cajan (L.) Millsp. In our study, CLA was found to promote osteoblast differentiation in human bone marrow mesenchymal stem cells (hBMSCs), as judged by increased cellular alkaline phosphatase activity and extracellular calcium deposits, and elevated protein expression of Runx2, collagen-1, bone morphogenetic protein-2, and osteopontin. Mechanistic studies revealed that hBMSCs undergoing osteoblast differentiation expressed upregulated mRNA levels of Wnt3a, Wnt10b, LRP5/6, Frizzled 4, β-catenin, Runx2, and Osterix from the early stage of differentiation, indicating the role of activated Wnt/β-catenin signaling pathway in osteoblast differentiation. Addition of CLA to the differentiation medium further increased the mRNA level of Wnt3a, Wnt10b, Frizzled 4, LRP5, and β-catenin, inferring that CLA worked by stimulating Wnt/LRP5/β-catenin signaling. Wnt inhibitor dickkopf-1 antagonized CLA-promoted osteoblastogenesis, indicating that CLA did not target the downstream of canonical Wnt signaling pathway. Treatment with CLA caused no changes in mRNA expression level, as well as protein secretion of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL), indicating that CLA did not affect the OPG/RANKL axis. Our results showed that CLA, which promoted osteoblast differentiation in hBMSCs, through activating Wnt/LRP5/β-catenin signaling transduction, is a promising anti-osteoporotic drug candidate.

A new natural halogen-containing stilbene derivative was isolated from the leaves of Cajanus cajan (L.) Millsp. and identified as 3-O-(3-chloro-2-hydroxyl-propanyl)-longistylin A by comprehensive spectroscopic and chemical analysis, and named cajanstilbene H (1). It is the first halogen-containing stilbene derivative found from plants. In human mesenchymal stem cells (hMSC) from bone marrow, 1 did not promote cell proliferation, but distinctly enhanced osteogenic differentiation of hMSC in time- and dose-dependent manners. In six human cancer cell lines, 1 showed a moderate inhibitory effect on cell proliferation, with IC₅₀ values of 21.42–25.85 μmol·L⁻¹.

To investigate the chemical constituents in the ethyl acerate extract of Lysimachia fortunei. The compounds were isolated by silica gel chromatography, and their structures were elucidated by NMR data and references. Nine natural constituents were isolated, and their structures were identified as 9, 19-cyclolanost-24-en-3-one (1), 24-ethyl-5alpha-cholesta-7, 22(E)-dien-3-one (2), 1-pentatriacontanol (3), beta-stigmasterol (4), 24-ethyl-5alpha-cholesta-7, 22(E)-dien-3beta-ol (5), palmitic acid (6), isorhamnetin (7), kaempferol (8) and quercetin (9) respectively. All compounds mentioned above were isolated from this plant for the first time, and compound 1, 2 and 5 were obtained from the genus for the first time.