Evaluation of the in vitro fungicidal activity of the dynamized essential oil of Aloysia polystachya before and after freezing

Background: The method of preserving substances of natural origin should not only maintain the microbiological safety of the product but also the integrity of its therapeutic potential. Essential oils obtained from plants are complex mixtures of substances and it is suggested to keep them under refrigeration for better conservation. On the other hand, homeopathic mother tincture prepared from plant is kept at room temperature. Aim: This work aimed to evaluate if the freezing process changes the in vitro antifungal activity potential of the homeopathic preparation Aloysia polystachya 1CH against Candida albicans. Methodology: The inoculum of C. albicans ATCC 10231 was cultivated in culture médium Sabouroud (Himedia®), standardized on a spectrometer and distributed in a 96-well plate. Then, A. polystachya 1CH was added to the wells, prepared according to the Brazilian Homeopathic Pharmacopoeia (FHB, 3rd edition) from A. polystachya essencial oil. An aliquot of this homeopathic preparation was frozen and after 40 days it was submitted to the same methodology for evaluation of the antifungal activity. After incubation, the plates were read with triphenyltetrazolic (TTC) (Vetec®). Results and discussion: The results of the in vitro evaluation showed that the freezing process retained the antifungal activity of the dynamized essential oil of A. polystachya 1CH against C. albicans. Conclusion: Under the conditions evaluated in this study, the freezing method presented as a viable method of conservation of dynamized plant material.