Quantitative evaluation of therapeutic effect of Liriope platyphylla on phthalic anhydride-induced atopic dermatitis in IL-4/Luc/CNS-1 Tg mice

Ethnopharmacological relevance

A variety of previous pharmacological studies have suggested that Liriope platyphylla may exert beneficial biological effects on inflammation, diabetes, neurodegenerative disorder, obesity, and atopic dermatitis (AD).

Aim of the study

The therapeutic effect of aqueous extract of Liriope platyphylla (AEtLP) on AD was quantified using the luciferase report system in IL-4/Luc/CNS-1 transgenic (Tg) mice.

Materials and methods

Alteration of the luciferase signal was quantified in IL-4/Luc/CNS-1 Tg mice co-treated with phthalic anhydride (PA) and AEtLP for 2 weeks using the IVIS imaging system. Phenotypes of AD were assessed by ear thickness analysis, measurement of immune-related organ weights, ELISA, and histological and pathological analysis in Tg mice.

Results

A strong luciferase signal was detected in the abdominal region of IL-4/Luc/CNS-1 Tg mice treated with only PA. However, this signal was significantly reduced in IL-4/Luc/CNS-1 Tg mice co-treated with PA+AEtLP in an AEtLP concentration-dependent manner. Especially, three organs, the thymus, pancreas, and submandibular lymph node (SL), showed a high signal response to PA treatment. Furthermore, to verify whether or not alteration of the luciferase signal is associated with AD, these disease response phenotypes were measured in the same group of mice. Common allergenic responses including increases in ear thickness, lymph node weight, IgE concentration, and infiltrated mast cells were detected in IL-4/Luc/CNS-1 Tg mice treated with PA. However, these responses were dramatically decreased by AEtLP treatment for 2 weeks.

Conclusion

These results indicate that the luciferase signal may successfully reflect the therapeutic effects of AEtLP in IL-4/Luc/CNS-1 Tg mice. Further, we suggest additional evidence that Liriope platyphylla may be considered as an effective therapeutic drug for the treatment of AD.