Fig 1.
In vivo inhibitory effect of crude EtOH (F1) on IgE-mediated passive cutaneous anaphylaxis reaction.
a) Experimental design of passive cutaneous anaphylaxis assay. Mouse ears were intradermally injected (i.d.) with anti-DNP-IgE. Twenty-four hours post sensitization, mice were orally administrated with F1 or dexamethasone then intravenously (i.v.) challenged with DNP antigen. Evans blue leakage was monitored at 2 hours after stimulation. b) Evans blue leakage after the antigen challenge. Dexamethasone was used as a positive control. c) Evans blue extracted from each ear was quantified using a spectrophotometer. Data are presented as mean ± SEM (n = 5 per group). *p < 0.05, compared with the vehicle control group.
Table 1.
Effects of X. tridentata extracts on IgE-mediated mast cell degranulation and cell viability of RBL-2H3 cells.
Table 2.
Total phenolic and total flavonoid contents of the extracts of X. tridentata.
Fig 2.
Principle component analysis and heat map visualization of X.tridentata extracts metabolic profiles.
Principal component 1 (PC1) represents the maximal variation of data. Principal component 2 (PC2) is orthogonal to the PC1 axis and accounts for the second highest variation. a) Principle component analysis for ESI positive mode b) Principle component analysis for ESI negative mode. Each point represents an individual LC-MS injection. c) Heat map of 35 features with the highest fold change of F3/F5 observed in ESI positive mode and d) in ESI negative mode.
Table 3.
Summary of metabolite features contributed to the discrimination between F3: EtOH/EtOAc and F5: EtOH/H2O fractions in ESI positive mode.
Table 4.
Summary of metabolite features contributed to the discrimination between F3: EtOH/EtOAc and F5: EtOH/H2O fractions in ESI negative mode.
Fig 3.
Isolation of major compounds from F3: EtOH/EtOAc.
a) Chromatogram of subfraction F3 from MPLC separation on a reversed phase silica gel column eluted with gradient system of MeOH and H2O (3–97%). The chromatographic signals at 256 nm (black) and 366 nm (orange) were detected. b) Chemical structures of the known compounds corresponding to peak1-4 (see S1 and S2 Appendices for the HRMS and NMR spectra, respectively).
Fig 4.
The levels of four significant metabolite features in different subfractions.
a) ESI+516.12723_3.168, b) ESI+448.10082_3.034, c) ESI+448.10108_3.251 and d) ESI+432.10612_3.604.
Fig 5.
Inhibitory effects on IgE-mediated RBL-2H3 cell degranulation.
a) The effects of the extracts (100 μg/mL) and active compounds (25 μM) derived from X. tridentata on intracellular ROS generation b) The effects of active compounds and ketotifen fumarate (25 and 100 μM) on β-hexosaminidase release. Ketotifen fumarate was used as a positive control. The values are presented as means ± SEM (n = 3). *p<0.05 and **p < 0.001, compared with the vehicle control.
Fig 6.
Inhibitory effects on compound 48/80-stimulated RBL-2H3 cell degranulation.
a) The effects of the active compounds and ketotifen fumarate (25 and 100 μM) on β-hexosaminidase release. Ketotifen fumarate was used as a positive control. The values are present as means ± SEM (n = 4). *p<0.05 and **p < 0.001, compared with the vehicle control. b) The effects of active compounds (25 μM) derived from X. tridentata on intracellular ROS generation.