Anti-inflammatory property and functional substances of Lonicerae Japonicae Caulis

Lonicerae Japonicae Caulis, the dried stem and branch of Lonicera japonica Thunb., is a Chinese Materia Medica known as Ren Dong Teng in Chinese with long use history in the traditional Chinese medicine (TCM) prescriptions. Lonicerae Japonicae Caulis possesses heat-clearing and detoxifying functions according to the TCM theory. In recent years, a large amount of experimental and clinical studies proved good anti-inflammatory effects of some heat-clearing and detoxifying herbs. The present study aims to reveal the anti-inflammatory property and functional substances of Lonicerae Japonicae Caulis.

For anti-inflammatory activity test, LPS-induced RAW 264.7 macrophages, DSS-induced SPF male C57BL/6J mice model, and LPS-induced SPF male ICR mice model were used in vitro and in vivo, respectively. The behavioral changes, organ damage, and the expression of inflammatory factors such as TNT-α and IL-6 mRNA expression were measured for activity evaluation. Lonicerae Japonicae Caulis samples were prepared by solvent extraction and subsequent column chromatography. The main components were identified and determined using UPLC-UV analysis as well as NMR interpretation after purification. To testify the contribution of main components for the anti-inflammatory activity, different samples were also prepared by compound-knockout strategy.

Ethanol extract of Lonicerae Japonicae Caulis could attenuate sickness symptoms in mice such as diarrhea, less activity, and depression. It could also alleviate multiple organ damage, and significantly inhibit the expression of pro-inflammatory factors such as TNF-α, IL-1β, IL-6 and IFN-γ in mice. Furthermore, the isochlorogenic acid-rich and biflavonoid-rich fractions and isochlorogenic acids A and C, and ochnaflavone could significantly down-regulate the mRNA expression of TNF-α and IL-6 in LPS-induced RAW 264.7 macrophages.

Lonicerae Japonicae Caulis possesses anti-inflammatory property. Its isochlorogenic acid-rich and biflavonoid-rich fractions do the major contribution. And their main components, isochlorogenic acids A and C, and ochnaflavone, take main responsibility for the anti-inflammatory property.