Inhibitory effect of Zingiber cassumunar Roxb. (Phlai) on nasal cytokine productions and eosinophilic recruitment in patients with allergic rhinitis.

BACKGROUND

Zingiber cassumunar Roxb. (Phlai) has been used for the treatment of allergies including allergic rhinitis (AR). Although the anti-histamine effects have been reported, assessment of nasal cytokine and eosinophil production had not been investigated.

OBJECTIVE

This study aimed to examine the effect of Phlai on alterations in nasal pro-inflammatory cytokine levels and eosinophil counts in nasal mucosa.

METHODS

This was a randomized, double-blind, three-way crossover study. Nasal concentrations of cytokines, namely interleukin (IL)-4, IL-5, IL-13 and interferron-gamma (IFN-γ), nasal smear eosinophilia as well as total nasal symptom score (TNSS) were evaluated before and after a 4 weeks treatment with 200 mg Phlai capsules or placebo in 30 AR patients.

RESULTS

We observed significant (p < 0.05) reduction in IL-5, IL-13 as well as the number of eosinophils in subjects given Phlai. The degree of improvement of TNSS after Phlai treatment was initially manifested in week 2 with the greatest effect in week 4. In contrast, there were no significant differences in all nasal cytokines, eosinophil counts or TNSS between before and after receiving placebo.

CONCLUSIONS

These findings provided the first evidence for the anti-allergic effect of Phlai which possibly involved inhibition of nasal pro-inflammatory cytokines production and eosinophilic recruitment. Phlai thus represents a promising herbal medicine for alleviating inflammation and AR symptoms.