The Chinese herbal medicine formula FAHF-2 completely blocks anaphylactic reactions in a murine model of peanut allergy

Background: Peanut allergy is potentially life threatening. There is no curative therapy for this disorder. We previously found that an herbal formula, food allergy herbal formula (FAHF)-1, blocked peanut-induced anaphylaxis in a marine model when challenged immediately posttherapy. Objective: To test whether FAHF-2, an improved herbal formula, from which 2 herbs, Zhi Fu Zi (Radix Lateralis Aconiti Carmichaeli Praeparata) and Xi Xin (Herbs Asari), were eliminated, is equally effective to FAHF-1, and if so, whether protection persists after therapy is discontinued. Methods: Mice allergic to peanut treated with FAHF-2 for 7 weeks were challenged 1, 3, or 5 weeks posttherapy. Anaphylactic scores, core body temperatures, vascular leakage, and plasma histamine levels after peanut challenge were determined. Serum peanut-specific antibody levels and splenocyte cytokine profiles were also measured. Results: After challenges, all sham-treated mice developed severe anaphylactic signs, significant decrease in rectal temperatures, significantly increased plasma histamine levels, and marked vascular leakage. In contrast, no sign of anaphylactic reactions, decrease in rectal temperatures, or elevation of plasma histamine levels was observed in FAHF-2-treated mice in 5 separate experiments. IgE levels were significantly reduced by FAHF-2 treatment and remained significantly lower as long as 5 weeks posttherapy. Splenocytes from FAHF-2-treated mice showed significantly reduced IL-4, IL-5, and IL-13, and enhanced IFN-gamma production to recall peanut stimulation in vitro. Conclusion: FAHF-2 treatment completely eliminated anaphylaxis in mice allergic to peanut challenged as long as 5 weeks posttherapy. This result was associated with downregulation of T(H)2 responses. FAHF-2 may be a potentially effective and safe therapy for peanut allergy.