Antiallergic effect of piperine on ovalbumin-induced allergic rhinitis in mice.

BACKGROUND

Allergic rhinitis (AR) is a global health problem that affects a large number of population. Piperine (PIP) has been reported to exhibit anti-inflammatory, anti-histaminic, and immunomodulatory activities; however, its antiallergic profile has not been studied.

OBJECTIVE

The objective of the study was to investigate the antiallergic potential of PIP in ova-albumin (OVA)-induced AR, mast cell degranulation (MSD), and OVA-induced paw edema.

METHODS

Mice were sensitized with OVA alternately on 1, 3, 5, 7, 9, 11, and 13th day. They were treated with either vehicle, PIP (10, 20, and 40 mg/kg, p.o.), or montelukast (10 mg/kg, p.o.) from the 14th to 20th day. On the 21st day, intranasal (OVA: 5% µl) challenge was done. Animals were evaluated for physiological parameters, biochemical parameters, spleen weight, expression of interleukins (IL-6 and IL-1β), and immunoglobin-E (IgE). Histopathology of nasal mucosa, lungs, and spleen was carried out. MSD and paw edema studies were made to understand the mechanism of action.

RESULTS

PIP (10, 20, and 40 mg/kg, p.o.) showed a significant dose-dependent protection with respect to nasal rubbing, redness of nose, and sneezing (p < 0.001) following nasal challenge. PIP dose dependently reduced histamine, NO concentration (p < 0.001), as well as reduced expression of IL-6, IL-1β, and IgE (p < 0.001) as compared with the control group. Histopathology showed inhibition of infiltration of eosinophils and hyperplasia. It dose dependently reduced MSD and paw edema (p < 0.001).

CONCLUSIONS

PIP acts by mast cell-stabilizing activity, exhibits immunomodulatory and anti-inflammatory activity, thereby providing an effective treatment for AR.