Full text loading...
薬理と治療
Abstract
Background Kuromoji(Lindera umbellata Thunb.)is a fragrant deciduous shrub belong to the Lauraceae family. Previous studies have shown that the hot water extract of Kuromoji has antiviral activity that inhibits the adsorption and invasion in infection of influenza virus. Methods A macromolecular compound–containing fraction was obtained using a dialysis membrane with 3.5 kDa molecular weight cut–off from the aqueous ethanol–soluble fraction of the hot water extract of Kuromoji. Molecular weight of the components in the fraction was estimated by gel filtration HPLC and molecular structure was analyzed by acid hydrolysis and phloroglucinol degradation. Antiviral activity was evaluated using Madin–Darby canine kidney (MDCK)cells and an influenza virus infection. Viral infection was visualized by immunofluorescence staining for the virus nucleocapsid protein(NP). To clarify the working point of the fraction, the amount of viral RNA in MDCK cells in time–of–addition analysis was quantified by real–time PCR. Results Gel filtration HPLC showed that the peak molecular weight of the fraction was 8.7×103 Da. Phloroglucinol degradation generated that catechin and epicatechin. The fraction suppressed NP expression. The viral mRNA was significantly suppressed when the fraction was added simultaneously with virus infection. Conclusions The macromolecular fraction of the hot water extract of Kuromoji is considered to be mainly composed of proanthocyanidins with catechin and epicatechin residues. This fraction showed antiviral activities that suppresses the expression viral NP and cytopathic effect shown by influenza virus. The suppressive effect is concluded to prevent the adsorption or entry of viruses into target cells. (Jpn Pharmacol Ther 2023;51:193‒201)
Data & Media loading...