Seasonal Dynamic Of Total Flavonoids,Chemical Composition,Antioxidant And Anti-tumor Potentials In Stenoloma Chusanum

Stenoloma chusanum(L.) Ching is known as herbal healer. In folk, it shows efficacies in cancer treatment, detoxification and hemostasis. S. chusanum has been reported for its high flavonoid content, strong antioxidant potentials, antibacterial effects etc. However, the previous work still focuses on its crude extract and there are few data on the biological ability and exact active ingredients in S. chusanum. Hence,the purpose of this work is to evaluate the seasonal dynamics of the total flavonoids, chemical components and biological activities in S. chusanum. The present work will be of great significancence in the medicinal value and exploitation of S. chusanum. The main results of this work are as followed: 1. The seasonal dynamics of the total flavonoids and phenolic content and their antioxidant activity in S. chusanum.The seasonal dynamics of the total flavonoids(TFC) and phenolic content(TPC) in different parts of S. chusanum and their antioxidant activity were investigated. The TFC and TPC in different parts of S. chusanum obviously exhibited a seasonal dynamic change. The content in the aerial part was higher than that in the subterranean part; The TFC and TPC in S. chusanum are relatively higher collected in winter and autumn, and in February the TFC and TPC was the highest, which was 24.63±1.34% and 9.58±0.41%. Additionally, the antioxidant activity including DPPH and ABTS free radical scavenging inhibitory, FRAP assay(reducing power) was investigated seasonally. The subterranean parts of S. chusanum manifested slightly higher antioxidant ability than the aerial parts; according to their IC50 values, the antioxidant capacity of S. chusanum collected at different month(February, May, August and November) remained stable. 2. The total flavonoid and phenolic content and antioxidant in different fraction of S. chusanum The TPC and TFC in the five fractions, including petroleum ether(PF), chloroform(CF), ethyl acetate(EF), n-butanol(NF) and water fractions(WF), were measured. The CF, EF and NF presented higher TFC and TPC, which ranged from 15.35%-26.33% and 44.34%-74.68%. And the antioxidant activity of five fraction in S. chusanum was, in decreasing order, as followed: EF > NF > CF > WF. Obviously, the EF, NF and CF possessed better antioxidant ability. 3. The anti-tyrosinase activity in S. chusanumThe crude extract(different parts) and fractions in S. chusanum showed great tyrosinase inhibitory. In the light of their IC50 values, ranging from 118.6 – 210.2 μg/m L, the crude extract of aerial part exhibited higher tyrosinase inhibitory effect than the other five fractions and the subterranean part, and the aerial part and PF was found to be better than arbutin(positive control). 4. Anti-tumor potential in S. chusanumThe crude extract(different parts) and fractions(EF, NF and CF) in S. chusanum were found toxic to K562 cells and could inhibit the proliferation of K562 cells. the S. chusanum extract could induce both necrosis and apoptosis of K562 cells, and it increased the percentage of cell apoptosis in a dose-dependent response. In addition, typical features of the apoptotic cells such as cytoplasmic membrane blebbing, nuclear contraction, nuclear fragmentation and nuclear contraction were visible after treatment with S. chusanum under fluorescence microscopy. 5. Compounds identification via LC/MS in S. chusanumThe chemical constitutions of the S. chusanum were analyzed using HPLC-DADESI-MS, which showed the presence of 12 flavonoids in the extract, and the aerial part had more flavonoids than the subterranean part which was consistent to their flavonoid contents. Additionally, 13 flavonoids were identified in the five fractions of S. chusanum, the ethyl acetate and n-butanol fractions had more flavonoids than the other three fractions.To summary, the flavonoids and phenolic contents in S. chusanum processes seasonal dynamic phenomenon, and flavonoids and phenol are rich in the materials harvested in winter and spring, which could be used for further development and utilization. Meanwhile, S. chusanum is found to be good antioxidant, anti-tyrosinase as well as anti-tumor agents, and some flavonoids of S. chusanum appears to be responsible for these effects. This work lay a foundation for medicinal exploitation for S. chusanum.