Compound 48/80-induced histamine release from isolated rat peritoneal mast cells

The rats were cervically dislocated under anesthesia with 40 mg/kg pentobarbital sodium). Peritoneal mast cells were harvested from male Wistar strain rats using decollation under 350 mg/kg chloral hydrate. A total of 5 ml of medium was injected into enterocoelia of every mouse and the abdomen was gently massaged for 5–10 min. The cells were purified using Percoll density centrifugation (Thermo Fisher Scientific, Inc.) at 8,000xg at 4°C for 10 min, as described previously (10). All cells (3×104 cells/tube) were incubated in physiological buffer solution (Beyotime Institute of Biotechnology, Haimen, China) for 20 min at 37°C. Artemisia extract, 0.1 ml phosphate-buffered saline (Wuhan Procell Science and Technology Co., Ltd., Wuhan, China) and 0.5 mg/ml compound 48/80 were blended altogether. The miscible liquids were incubated for 20 min on ice. The histamine content was measured by means of a fluorometric assay (ELISTA kit; E-EL-0032c, Elabscience, Wuhan, China) by an ELx800 microplate reader (Biotek Instruments, Inc., Winooski, VT, USA). Briefly, the miscible liquids were incubated for 20 min on ice and 80 µl of affinity chain enzyme-HRP at 37°C was added for 1 h. Next, every well was washed with scrubbing solution. The histamine content was measured by means of a fluorometric assay (Synergy 2 Microplate Reader, Bio-Tek, USA) at 450 nm.