A Chinese herbal medicine formula, FAHF-2, completely blocks anaphylaxis in a murine model of peanut allergy

Abstract

Rationale Food allergy is a serious and growing health problem. We previously showed that Chinese herbal medicine formula, FAHF-1, protected peanut (PN)-allergic mice from anaphylaxis following oral PN challenge. We have now tested an improved formula, FAHF-2, containing fewer herbs. Methods We employed a 14-week oral PN sensitization and challenge protocol in C3H/HeJ mice. Oral treatment with FAHF-2 was performed twice daily for 7 weeks, commencing at week 3 or week 8. Anaphylactic reactions were assessed by evaluation of symptom scores, plasma histamine levels and body temperatures. Splenocytes of challenged mice were isolated cultured to evaluate cytokine production. Results Peanut-specific IgE was significantly reduced in FAHF-2-treated mice compared to the sham-treated mice in both early (3072 ± 101 vs 7017 ± 9.6 ng/ml, p<0.001) and late treatment (2201 ± 190 vs 3224 ± 249 ng/ml, p<0.05) protocol groups. FAHF-2 completely protected mice from anaphylaxis to peanut challenge. No symptoms were seen in FAHF-2-treated mice whereas sham-treated mice had an average score of 2.7 (scale of 0-5). Consistently, body temperatures of FAHF-2 treated mice were markedly higher (37.2 vs 34.6 oC, p<0.05) and plasma histamine were significantly lower (2483 ± 191 vs 18,488 ± 2194 ng/ml, p<0.001) than sham-treated mice. PN-stimulated splenocytes from FAHF-2 treated mice showed significantly lower production of Th2 cytokines IL-4 (35.0 ± 11 vs 126.6 ± 25.8 pg/ml, p<) and IL-5 (759.0 ± 157 vs 1063.5 ± 195 pg/ml, p<0.05), but no difference in IFN-γ production. Conclusion FAHF-2 completely prevented anaphylaxis in PN-allergic mice and down-regulated Th2 responses