Persimmon leaf extract and astragalin inhibit development of dermatitis and IgE elevation in NC/Nga mice

Chemical structure of astragalin and chromatogram of persimmon leaf extract monitored by UV detector. HPLC conditions: column, YMC-pack ODS-A A-312; mobile phase, water/acetonitrile/2-propanol (180:38:2); flow rate, 1.0 mL/min; detection wavelength, 350 nm.

Inhibitory effect of persimmon leaf extract and astragalin on histamine release from KU812 cells stimulated with anti-Fcϵ receptor mAb (CRA-1). Cells (10⁴ cells) were at first incubated with persimmon leaf extract (final concentrations, 0.01% and 0.005%) and astragalin (final concentrations, 0.00005% and 0.000025%) on ice for 30 minutes and incubated with 15 μg/mL CRA-1 at 37°C for 30 minutes. Histamine content of the supernatant was measured by means of ELISA. Positive and negative controls indicate histamine content with or without CRA-1. Values represent the mean ± SD of 3 determinations. *P < .05 and **P < .01; significantly different from positive control.

Inhibition of PCA reaction by means of persimmon leaf extract or astragalin in ddY mice. ddY mice were injected with anti-DNP IgE antibody. Persimmon leaf extract or astragalin was orally administered into mice, and 1 hour later, DNA-BSA was challenged. Fifteen minutes later, the thickness of both ears was measured. Values represent the mean ± SD of 6 determinations from 3 mice. **P < .01 and ***P < .001; significantly different from positive control.

Clinical features of NC/Nga skin. NC/Nga mice were provided with one of the following diets ad libitum: A, control diet (MF diet containing 0.125% of α-corn starch, n = 5); B, persimmon leaf extract diet (MF diet containing 0.125% of persimmon leaf extract at 250 mg/kg, n = 5); or C, astragalin diet (control diet plus astragalin at 1.5 mg/kg, n = 5) during the 8-week experiment. The photograph was taken at 13 weeks.

Effect of persimmon leaf extract or astragalin on clinical scores of skin symptoms and serum IgE level. Clinical scores and serum IgE level were measured. Values represent the mean ± SD. *P < .05 and **P < .01; significantly different from control diet.

Histologic features of skin lesions. Hematoxylin and eosin–stained sections of the ear from control NC/Nga mice (A), persimmon leaf extract mice (B) , or astragalin mice (C) .

IL-4 and IL-13 synthesis by spleen cells from astragalin or persimmon leaf extract (PLE) mice is suppressed. Spleen cells from mice at 13 weeks of age were stimulated with anti-CD3 plus anti-CD28 antibodies for 2 days. IL-4, IL-13, or IFN-γ in the culture supernatants was measured by ELISA. Values represent the mean ± SD. *P < .05.