RESUMO
Objective: To study the antioxidation activities in vitro of a comment flavonoid component named vicenin Ⅱ(Apigenin 6,8-di-C-glucoside) in Dendrobii Officinalis Caulis from different origin places and investigate its effects on apoptosis of HepG2 cells. Method: The antioxidation activities in vitro of vicenin Ⅱ (0.005-1 g·L-1) were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), salicylic acid and 2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid(ABTS) and copper ion reduction assays. Methye thiazolye telrazlium(MTT) assay was used to test the inhibitory effect of vicenin Ⅱ(12.5~100 μmol·L-1) on proliferation of 6 tumour cells in vitro. In subsequent apoptosis experiment, the concentration of vicenin Ⅱ was 75 μmol·L-1. The morphological changes of HepG2 cells were evaluated by Hoechst 33258 under fluorescence microscope; and the cell apoptosis rate was detected by flow cytometry with AnnexinV/PI apoptosis assay kit. The mRNA expressions of mitogen activated protein kinase (MAPK) pathway related apoptotic genes were detected by Real-time PCR assay. Result: The 1 g·L-1 vicenin Ⅱ showed 48.82% and 22.01% for DPPH scavenging rate and Cu2+ reduction rate respectively(P-1 vicenin Ⅱ showed 86.88% for ABTS scavenging rate(P-1 Vicenin Ⅱ, the cells survival rate was 45.69%(PPN-terminal kinase (JNK), and nuclear transcription factor (NF)-κB were increased(PConclusion: The general flavone glycosides component vicenin Ⅱ of Dendrobii Officinalis Caulis from different origins has a certain antioxidation effect and significant inhibitory effect on proliferation, and could induce apoptosis on HepG2 cells probably by regulating the expression of related genes in MAPK pathway and Bax/Bcl-2.
RESUMO
Objective: To extract,isolate,purify and identify the structures of the flavonoid glycoside in Dendrobium officinale from two different origin places (Danxia species and Yunnan Guangnan species),and provide experimental reference for confirming the common flavonoid glycoside components in D. officinale. Method: ① 70% ethanol was applied to extract the total flavonoids in leaves of D. officinale from two different species. Organic solvents petroleum ether,acetic ether and water saturated n-butyl alcohol were used in turn to extract the crude extraction. Then AB-8 Macroporous resin,Sephadex LH-20 and ODS chromatographic column were applied to isolate and purify the water saturated n-butyl alcohol extraction fraction. The structures of flavonoid glycoside were identified by studying physicochemical property,applying modern spectroscopy method like HPLC,ESI-MSn,1H-NMR,13 C-NMR,etc. ② HPLC characteristic spectrum technique was used to analyse and compare the common flavonoid glycoside components in Dendrobium officinale from different origin places (Danxia species,Yunnan Guangnan species,Guangxi Tiepilan species and Zhejiang native species). Result: Five flavonoid glycoside compounds were isolated from the crude extractions of the leaves of D. officinale from two different species,and they were identified as rutin,vicenin Ⅱ,viceninⅠ,violanthin and isoviolanthin. The characteristic spectrum of vicenin Ⅱ and viceninⅠwere detected in stems of D. officinale from four different origin places (Danxia species,Yunnan Guangnan species,Guangxi Tiepilan species and Zhejiang native species),and vicenin Ⅱ had a better separation degree in the characteristic spectrum. However,the characteristic spectrum of violanthin and isoviolanthin were more obvious in Yunnan Guangnan species and Guangxi Tiepilan species,while rutin was obvious in the Danxia species. Conclusion: Vicenin Ⅱis the common flavonoid glycosides component in D. officinale from different origin places (Danxia species,Yunnan Guangnan species,Guangxi Tiepilan species and Zhejiang native species),and can be used as the internal reference material for the characteristic spectrum of D. officinale.
RESUMO
Objective:To establish an HPLC method for the simultaneous determination of viceninⅡ, isoschaftoside and schafto-side in Isodon lophanthoides, and analyze their content dynamic changes. Methods:The HPLC system consisted of a Phenomenex luna C18(250 mm ×4.6 mm, 5 μm)column and a solution system of methanol and 0.5% formic acid with gradient elution, the flow rate was 0. 8 ml·min-1 and the detection wavelength was 334 nm at the column temperature of 25℃and the injection volume was 10 μl. Results:The linear range of viceninⅡ, isoschaftoside and schaftoside was 0.130-3.110 μg(r =0.999 8), 0.180-4.540 μg(r =0.999 9) and 0.080-1.970 μg(r =0. 9999), respectively. The average recovery was 96.8% (RSD =1.9%), 99.2% (RSD =1. 6%) and 97. 1% (RSD=1. 6%) (n=6), respectively. The above three kinds of water-soluble flavonoids from seedling stage to significant accumulation, isoschaftoside and schaftoside reached the highest value in March and August, the content of VitexinⅡ in January and April tends to be stable, in May began to increase gradually, reached the maximum value in August, then began to de-crease. Conclusion:With the contents of water-soluble flavonoids as the indicators, the best harvest time of Isodon lophanthoides is March and August, and the quality of the medicinal materials harvested in August is the best.