Quality Characterization Of Viscum Coloratum And Primary Study On Effect Of Different Hosts

Viscum coloratum(Kom.)Nakai is a well-known pharmaceutical hemiparasite distributed throughout China and commonly used for the treatment of rheumatism,arthritis,hypertension,and fetal restlessness in traditional Chinese medicine.Although it is documented in the Pharmacopoeia of the People’s Republic of China that V.coloratum can be parasitized on any plant,it is most commonly found on mulberry,elm,poplar,maple and pear trees.Given there is metabolic molecular interactions between V.coloratum and its host plant,the influence of host plant’s status on the quality and safety of Visci Herba could not be ingored.However,there are limited researches to investigate on this currently,which leaves much room for further exploration.In this study,24 batches of Visci Herba samples were collected from 14 host plant species in 5 producing areas from 3 provinces in China.The quality of V.coloratum was characterized by analysing its primary metabolites,secondary metabolites and biological potencies through multi-disciplinary techniques and methods.Meanwhile,the haustorium was used as an intermediary for the first time to explore the chemical interactions between host plants and V.coloratum.1.The hyperspectral imaging approach was performed to analyse the 119 Visci Herba samples from 6 host plants in 3 provinces.The results showed multivariate clustering,suggesting that the qualities of Visci Herba from diverse sources are different.2.The chemical components of Visci Herba were tested by UPLC-QTOF/MS.Fifty-five components were identified,including 29 flavonoids,8 diarylheptanones,8 phenolic acids and 10 other constituents.To further analyse the ingredients of the 29 flavonoids,six quality losses of filtering method was developed,by which it was speculated that dihydrogen flavone and flavonol were the dominant components,including 4 quercetin flavonoids,6 isorhamnetin flavonoids,11 homoeriodictyol flavonoids,5 eriodictyol flavonoids and 3 naringin flavanone flavonoids.3.To determine the quantity of oleanolic acid in Visci Herba,the UPLC-ELSD method was conducted.The results showed that the amount of oleanolic acid in the samples was in the range of 0.8-6.4 mg/g,in which V coloratum from the hosts of Pterocarya stenoptera C.DC.,Populus davidiana,Quercus wutaishanica,Robinia pseudoacacia and Populus nigra var had relatively high value of over 4.0 mg/g.4.The proteins of Visci Herba were analysed and quantified by an optimized protein extraction method,and the lectins of V.coloratum were analysed by sodium dodecyl sulfonate-polyacrylamide gel electrophoresis.We found Visci Herba from different host plant species contained different amounts of protein,with higher concentrations in samples from Morus alba L.,Populus simonii Carr.and Pterocarya stenoptera C.DC.,while lectins were conceivably higher in samples from Morus alba L.and Pterocarya stenoptera C.DC..5.The biological potencies of Visci Herba were examined by in vitro cellular experiment and also tested in zebrafish.The results showed that Visci Herba exhibited cytotoxic effects on lung cancer A549,liver cancer Hep G2 and breast cancer MCF7 cells.Besides,it inhibited the formation of thrombosis and promoted tissue regeneration or wound healing in zebrafish.Visci Herba from different host species displayed different magnitudes of biological potencies:the induced cytotoxicity was stronger in samples from Morus alba L.and Pterocarya stenoptera C.DC.,which might result from their higher levels of lectin;the process of thrombosis prevention and healing facilitation were more prominent in samples from Populus davidiana,which might due to their higher amount and wider variety of flavonoids.6.For 14 batches of samples from 14 host species in 3 provinces,the secondary metabolites of Visci Herba were analyzed by UPLC-QTOF/MS and stoichiometry.It was revealed that both origin and host species were determinant factors of the chemical composition of Visci Herba.The level of naringenin-caffeoly-glucoside,viscumneoside Ⅲ,homoeriodictyol-O-glucosyl-apiosyl-glucoside,eleutheroside E and polygalatenoside E were affected diversely by different host species.Furthermore,the chemical constituents of V.coloratum,its hosts,the haustorium,and the nodules formed between V.coloratum and the host were tested by UPLC-QTOF/MS.The clustering analysis result showed that the haustorium and nodule had similar contents with the hosts,but they were significantly different from V.coloratum.C22,C23,C3,C35,C21,C36,C40,C11 and C25 might be the interacting agents between V.coloratum and its hosts,which needs to be further investigated.In conclusion,V.coloratum from different hosts has significantly different primary metabolites,secondary metabolites and biological potencies,indicating host species plays an important role in the nature and quality of Visci Herba.In addition,we showed that there is chemical exchange between V.coloratum and its host,presumably through the haustorium and the nodules formed between them.