Identification of proteins in preparations of Candida species used in homeopathic medicinal products

Preparations with Candida albicans and C. parapsilosis have been safely used as active substances in isopathic remedies for over 30 years. Isopathy is a special kind of homeopathy [1]. Water-soluble fractions after cell mill treatment and different purification steps are obtained from both yeast and named e volumine cellulae (lyophil., steril.) [2]. D3 to D5 potencies of these starting materials are used e.g. for the treatment of eczema or mycotic skin disorders (marketing authorizations for different dosage forms of Albicansan and Pefrakehl in Switzerland).

The aim of the study was to characterize the protein fraction of the active substances.

The proteins in the extracts were quantified by colorimetric assays according to standard protocols [3]. This revealed an amount of 11% (C. parapsilosis) and 35% (C. albicans) of protein of the whole dry mass. The proteins were then identified by LC-MALDI mass spectrometry in a bottom-up approach. The crude protein extract was directly digested using trypsin followed by separation of the peptides by nano-rpHPLC coupled to mass spectrometry. 99 proteins from C. albicans and 131 proteins from C. parapsilosis could be identified. According to the gene ontology data, approximately 80% of the proteins belong to cellular metabolic processes.

References: [1] Wiethoff K, Kracke A (2010) Report Naturheilkunde 14: 56–60

[2] Bader G, Akkoyun A, Wiethoff K (2010) Planta Med 76: 1262

[3] Lowry OH et al. (1951)J Biol Chem 193: 265–275