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Breza Betula alba (Betulaceae)

Breza Betula alba (Betulaceae)

Breza (Betula)

European Union herbal monograph on Betula pendula Roth and/or Betula pubescens Ehrh. as well as hybrids of both species, folium

Assessment report on Betula pendula Roth and/or Betula pubescens Ehrh. as well as hybrids of both species, folium

 

U PRIPREMI

Betulae folium 1174

Betula pendula Roth. i/ili Betula pubescens Ehrh. i hibridi

 

DEFINITION Fresh bark of the stem of young twigs of Betula alba L. (Betula pendula Roth; Betula verrucosa Ehrh.) and/or of Betula pubescens Ehrh.

 

 

Birch (Betula pendula)

 

Synonyms / Common Names / Related Terms

Bet v 1, Bet v 1-fragments, Bet v 1-trimer, Betula, Betula 30c, Betula davurica Pall., Betula ermanii Cham., Betula grossa Sieb. et Zucc., Betula maximowicziana, Betula maximowicziana Regel, Betula nana, Betula nana L., Betula occidentalis, Betula pendula, Betula pendula Roth., Betula papyrifera Marsh., Betula platyphylla var. japonica, Betula platyphylla Sukatchev var. japonica (Miq.) Hara, Betula pubescens Ehrh., Betula verrucosa, Betulaceae (family), betulin, betulinic acid, birch pollen allergen (Bet v 1), downy birch, dwarf birch, Japanese white birch, lupeol, mountain birch, natural birch pollen extract, oleanolic acid, paper birch, rBet v 1, rBet v 2, rBet v 4, recombinant Betula verrucosa (rBet v 1), silver birch, white birch.

 

Note: This monograph does not cover birch immunotherapy. For more information on immunotherapy, please see the Natural Standard allergy database.

 

Mechanism of Action

Pharmacology:

  • Constituents: Birch contains betulinic acid, betulin, oleanolic acid, and lupeol.2
  • Diuretic effects: Birch may have diuretic effects, according to secondary sources.
  • Immunologic effects: Birch pollen is a common allergen, causing symptoms ranging from atopic dermatitis to rhinitis to asthma.1 In fact, binding of birch allergens to IgE on mast cells and basophils releases inflammatory mediators in nasal secretions.4 Because it is such a common allergen, birch pollen is frequently used in immunotherapy, although the mechanism of action is currently poorly understood. In conventional birch pollen immunotherapy, the cytokine profile of the circulating pool of allergen-specific T-cells is not changed during birch-pollen season.5 However, part of the mechanism of immunotherapy may involve the induction of peripheral T-cell tolerance and the increased production of specific IgG and IgG4. Early in immunotherapy treatment, stimulation by allergens may lead to systemic changes in Th2-like cytokine production and the early increase in allergen-specific IgE is a consequence of enhanced IL-4 production.6 In addition, birch pollen immunotherapy may inhibit the serum IgE-facilitated allergen presentation needed to obtain optimal T cell activation at the low allergen concentrations present in vivo, thereby reducing immunological response to allergens.7 Sublingual immunotherapy also reduces eosinophil infiltration in nasal mucosa, thereby reducing inflammation and significantly improving pulmonary function.8 In a study, patients with birch allergy had a significantly increased eotaxin concentration compared to controls, and immunotherapy significantly reduced the levels of eotaxin.9 Immunotherapy also reduces leukotriene release of peripheral leukocytes.10 Using genetically modified birch allergens reduces immediate skin reactions11 and induces IgG antibody responses against birch pollen in serum and mucosal fluids, possibly abrogating allergen-induced inflammation12. Interestingly, the mechanisms supporting bronchial hyperresponsiveness during allergic rhinitis may be different from those in asthma.3 As an aside, the birch pollen allergens show ribonuclease activity in vitro.13

 

Pharmacodynamics/Kinetics:

  • Insufficient available evidence.

 

References

  1. Bergmann, R. L., Edenharter, G., Bergmann, K. E., Forster, J., Bauer, C. P., Wahn, V., Zepp, F., and Wahn, U. Atopic dermatitis in early infancy predicts allergic airway disease at 5 years. Clin Exp Allergy 1998;28(8):965-970. 9756200
  2. Huyke, C., Laszczyk, M., Scheffler, A., Ernst, R., and Schempp, C. M. [Treatment of actinic keratoses with birch bark extract: a pilot study]. J Dtsch Dermatol Ges 2006;4(2):132-136. 16503940
  3. Rak, S., Heinrich, C., Jacobsen, L., Scheynius, A., and Venge, P. A double-blinded, comparative study of the effects of short preseason specific immunotherapy and topical steroids in patients with allergic rhinoconjunctivitis and asthma. J Allergy Clin Immunol 2001;108(6):921-928. 11742269

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