Silencing Peanut Allergy: A Chinese Herbal Formula, Fahf-2, Completely Blocks Peanut-induced Anaphylaxis for up to 6 Months Following Therapy in a Murine Model Of Peanut Allergy

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RATIONALE: We previously demonstrated that treatment with the Chinese herbal formula, FAHF-2, fully protected peanut allergic mice against anaphylaxis when challenged 5 weeks post-therapy. In this report we extended these studies to evaluate prolonged protection by FAHF-2.

METHODS: Peanut-sensitized mice were initially treated with FAHF-2 for seven weeks prior to commencement of oral challenges. Mice were periodically challenged up to week 50, after which they received a second course of FAHF-2 treatment for ten weeks. Mice were finally challenged at week 66.

RESULTS: FAHF-2 treated mice were completely protected (p<0.001) against peanut-induced anaphylaxis following challenges administered up to week 34(∼1/4 the life expectancy of mice). Subsequent challenges at weeks 40 and 50 showed only modest declines in protection (1/10 reactions at week 40, P<0.001; 3/10 reactions at week 50, p<0.001). After re-treatment with FAHF-2, complete protection was restored in treated mice since no mouse reacted at week 66 challenge, indicating no refractoriness to FAHF-2 treatment. Plasma histamine levels at all challenges were significantly lower in FAHF-2 treated mice (P<0.001) and PN-specific IgE levels in these mice were markedly reduced through the duration of the experiment (2309±313 ng/ml vs 4215±367 ng/ml, P<0.01 at final challenge). FAHF-2 treated mice also showed prolonged reduction in Th2 cytokines (40% reduction in IL-4; 68% reduction in IL-5, week 50).

CONCLUSIONS: FAHF-2 provided prolonged protection to anaphylaxis in peanut allergic mice and full protection was restored following re-treatment. These observations, if reproducible in humans, suggest that FAHF-2 may be a highly effective treatment for peanut allergy.