ABSTRACT
UVB radiation changes several photoaging pathway in the body, thereby prompting skin injury. Besides, chronic UVB radiation leads to photoaging, sustained immunosuppression, and photocarcinogenesis. We investigated the protective effect of Timosaponin AIII (TA-III), a naturally occurring steroidal saponin separated from Anemarrhena asphodeloides, against UVB-induced invasive properties of human epidermal keratinocytes (HEKs) and human dermal fibroblasts (HDF). No cytotoxicity was observed up to 50 nM concentration of TA-III. Similarly, TA-III inhibited UVB-induced cyclooxygenase-2 (COX-2), matrix metalloproteinase-9 (MMP-9) transcription level and protein expression in a dose-dependent manner at non-cytotoxic dose. Further, TA-III decreased UVB-induced invasion in primary skin cells. Additionally, TA-III suppressed UVB-stimulates mitogen-activated protein kinase (MAPK) signaling, activator protein-1 (AP-1) and nuclear factor kappa B (NF-κB) activation, thereby preventing the overexpression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and COX-2 in human epidermal keratinocytes cells. Furthermore, TA-III prevented UVB-mediated formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) and activation of DNA repair enzymes and, cell cycle arrest genes like as proliferating cell nuclear antigen (PCNA), structural maintenance of chromosomes protein 1 (SMC1). This results support that understanding into the molecular action of TA-III, which can be useful for developing photoprotective agents.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Keratinocytes/drug effects , Keratinocytes/radiation effects , Saponins/pharmacology , Steroids/pharmacology , Ultraviolet Rays , Cell Survival/drug effects , Cell Survival/radiation effects , Cells, Cultured , Cyclooxygenase 2/genetics , DNA Damage , Humans , Keratinocytes/metabolism , Matrix Metalloproteinase 9/genetics , Mitogen-Activated Protein Kinases/metabolism , NF-kappa B/metabolism , Radiation-Protective Agents/pharmacology , Signal Transduction/drug effects , Transcription Factor AP-1/metabolismABSTRACT
Coix lachryma-jobi L. var. ma-yuen has been a source of food and traditional folk medicine in some parts of Asia for thousands of years; however, the roots of this plant have not been phytochemically investigated. Herein, we report the isolation of a new benzoxazinoid glycoside, coixlachryside B (1), along with ten known compounds (2-11), from the roots of C. lachryma-jobi var. ma-yuen using a variety of chromatographic methods. Among the known compounds, the absolute configuration of compound 4 was determined. The structures of all compounds were elucidated by interpreting NMR spectroscopic data, and experimental and calculated electronic circular dichroism spectra.
