RESUMO
AIM: To study the chemical constituents of the roots and stem bark of Kadsura coccinea. METHOD: Compounds were isolated by column chromatography on silica gel and Sephadex LH-20, and finally purified by prep-HPLC. Their structures were elucidated by extensive spectroscopic methods, including 1D- and 2D-NMR, and HR-ESI-MS. RESULTS: Two compounds were determined as (7'S,8'S,8R)-(8ß,8'α)-dimethyl-4,4'-dihydroxy-5,3'-dimethoxy-5'-cyclolignan glucoside (1) and micrandiactone H (2), respectively. CONCLUSION: Compunds 1 and 2 are new and neither showed inhibitory effects on nitric oxide (NO) production in lipopolysaccharide-induced RAW264.7 macrophages.
Assuntos
Glicosídeos/química , Kadsura/química , Lignina/química , Extratos Vegetais/química , Animais , Linhagem Celular , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Lignina/isolamento & purificação , Lignina/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Camundongos , Estrutura Molecular , Óxido Nítrico/metabolismo , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Raízes de Plantas/químicaRESUMO
The development of melanogenic inhibitors is important for the prevention of hyperpigmentation, and, recently, consideration has been given to natural materials or traditionally used ingredients such as Chinese medicine. The aim of this study is the evaluation of a new anti-melanogenic candidate, kadsuralignan F, from the natural plant Kadsura coccinea, as well as the determination of mechanisms of melanogenesis inhibition at a molecular level. Kadsuralignan F significantly reduced melanin synthesis in a dose-dependent manner in a murine melanocyte cell line and human skin equivalents. There was no direct inhibition on mushroom tyrosinase or cell-extract tyrosinase activity, and mRNA expression of tyrosinase and other melanogenic genes such as tyrosinase-related protein-1 (trp-1) or trp-2 were not affected by kadsuralignan F. Interestingly, the protein level of tyrosinase was dramatically downregulated with kadsuralignan F treatment. We found that a decrease of tyrosinase protein by kadsuralignan F was fully recovered by MG132, a proteasome inhibitor, but not by chloroquine, a lysosome inhibitor. In this study, we found that kadsuralignan F, a lignan from an extract of Kadsura coccinea, has an inhibitory activity on melanin synthesis through tyrosinase degradation. These findings suggest that kadsuralignan F can be used as an active ingredient for hyperpigmentation treatment.
