Inhibitory effects of curcumin on passive cutaneous anaphylactoid response and compound 48/80-induced mast cell activation

Abstract

Mast cells participate in allergies and inflammation by secreting a variety of pro-inflammatory mediators. Curcumin, the active component of turmeric, is a polyphenolic phytochemical with anti-tumor, anti-inflammatory, anti-oxidative, and anti-allergic properties. The effects of curcumin on compound 48/80-induced mast cell activation and passive cutaneous anaphylactoid reactions are unknown. In this report, we investigated the influences of curcumin on the passive cutaneous anaphylactoid response in vivo and compound 48/80-induced mast cell activation in vitro. The mechanism of action was examined by calcium uptake measurements and cAMP assays in mast cells. Curcumin significantly attenuated the mast cell-mediated passive cutaneous anaphylactoid reaction in an animal model. In agreement with this in vivo activity, curcumin suppressed compound 48/80-induced rat peritoneal mast cell (RPMC) degranulation and histamine release from RPMCs. Moreover, compound 48/80-elicited calcium uptake into RPMCs was reduced in a dose-dependent manner by curcumin. Furthermore, curcumin increased the level of intracellular cAMP and significantly inhibited the compound 48/80-induced reduction of cAMP in RPMCs. These results corroborate the finding that curcumin may have anti-allergic activity.

Keywords: Anaphylactoid reaction; Calcium; Curcumin; Histamine; Mast cell.

Fig. 1

Effect of curcumin on rat peritoneal mast cell (RPMC) viability. RPMCs were treated with the various concentrations of curcumin for 2 hours. RPMC viability was determined by MTT assay and the percentage of viability was calculated as a ratio of A₅₇₀ of control cells (treated with HEPES-Tyrode buffered solution). Each data value represents the mean±S.E.M. of five independent experiments.

Fig. 2

Inverted light micrographs of rat peritoneal mast cell (RPMC, arrows). (A) The normal RPMC in HEPES-Tyrode buffered solution. (B) The Degranulated RPMC after the addition of compound 48/80. (C) The RPMCs observed within 10 minutes after the addition of curcumin (50 µM) show similar findings as seen in Fig. 2A. (D) The RPMCs pretreated with curcumin observed within 10 minutes after the addition of compound 48/80, show similar findings as seen in Fig. 2C. Bars=10 µm.

Fig. 3

Effect of curcumin on compound 48/80-induced histamine release from rat peritoneal mast cell (RPMC). RPMCs were preincubated with curcumin at 37℃ for 5 minutes prior to the incubation with compound 48/80. Curcumin dose-dependently inhibited compound 48/80-induced histamine release. Each data value represents the mean±S.E.M. of five independent experiments. ^*P<0.001, significantly different from the control value. C48/80: compound 48/80.

Fig. 4

Effect of curcumin on compound 48/80-induced calcium uptake into rat peritoneal mast cell (RPMC). RPMCs were preincubated with curcumin at 37℃ for 5 minutes prior to the incubation with compound 48/80. Curcumin dose-dependently inhibited compound 48/80-induced calcium uptake into RPMCs. Each data value represents the mean±S.E.M. of five independent experiments. ^*P<0.05, significantly different from the control value. C48/80: compound 48/80.

Fig. 5

Effect of curcumin on the compound 48/80-induced decrease of cAMP level in rat peritoneal mast cell (RPMC). Various concentrations of curcumin were added into the RPMCs suspension for 5 minutes, and cAMP levels were measured. Curcumin inhibited the compound 48/80-induced cAMP reduction of RPMCs in a dose-dependent manner. Each data value represents the mean±S.E.M. of five independent experiments. ^*P<0.05 and ^†P<0.001, significantly different from the normal value; ^‡P<0.001, significantly different from the control value. C48/80: compound 48/80.