Characterization of immunostimulatory activities of fractions obtained from Taraxacum officinale
Plants of the genus Taraxacum officinale have a history of use in Korean, Chinese, Arabian and Native American traditional medicine to treat a variety of infectious diseases and cancers . In Traditional Medicine, it is also known as choleretic, diuretic, anti-rheumatic and anti-inflammatory properties . In the current study, in vitro immunostimulatroy effects of Taraxacum officinale have been investigated. The crude methanolic extract of the whole plant was sequentially fractionated into three subextracts; explicitly, ethyl acetate (EtOAc), n-butanol, and remaining water extracts. Further studies were carried out on the most active subextract, i.e. the EtOAc subextract, was further subjected to fractionation through successive column chromatographic applications on Silica gel 60. For the activity assessment, each extract or fraction was submitted to bioassay systems; in vitro neutrophil migration, spleen lymphocyte proliferation, nitric oxide (NO) production and phagocytosis for immunostimulatory activity assessment. Among the fractions, the ethyl acetate fraction was identified to be most effective in the migration activity of neutrophils, spleen cell proliferation, phagocytosis and NO production, significantly greater than media control. Sequential chromatographic separation of the ethyl acetate fraction on Silica gel column resulted in a more purified preparation that retained the immunostimulatory activity. From the EtOAc subextract, a major component was isolated and its structure was determined as taraxinic acid β-D-glucoside by means of spectral techniques.
This study provides a new scientific data on Taraxacum officinale extracts or individual components present in the extracts may be of value as novel immunostimulatory agents.
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