Biocide effects of Chrysactinia mexicana Gray

Chrysactinia mexicana Gray (Asteraceae), commonly known as St. Nicholas's herb or „false Damiana“, is a small aromatic shrub widely distributed throughout central and northern Mexico, where it is extensively used in folk medicine treating several diseases [1]. In order to corroborate and to explain the qualities attributed to this species, diverse experimental works have been undertaken of which a review will be presented: (a) The antifungal activity of the alcoholic extract of this species has been evaluated on Aspergillus flavus. Antifungal screening was performed using Czapek agar. A. flavus SRRC 1273 from the NCAU (Peoria, IL) was used for the determination of antifungal activity; the diffusion method was from wells on agar plates. The alcoholic extract was placed in a well of 6mm in diameter made on the test plate and cultured for 72h at 28±1°C. Inhibition diameters were determined after incubation. The antifungal screening showed that the extract caused significant inhibition of A. flavus growth. The extract was fungistatic and fungicidal against A. flavus [2]. (b) Also the antibacterial effect of the ethanolic and aqueous extracts (200mg/ml of dry matter) of C. mexicana against Shigella flexneri, S. boydii, S. sonnei, S. dysenteriae, Salmonella enteridis, S. typhi and Escherichia coli was shown by the method of Kirby-Bauer by diffusion in Muller Hinton agar, modified as well diffusion technique. The aqueous extract significantly reduced the development of S. boydii and S. flexneri, whereas the alcoholic extract displayed antibacterial activity against all the studied bacteria except E. coli [3]. Conclusions: The daily drinking of St. Nicholas' herb infusion seems to be widely justified by its antibacterial and fungicide actions, since the problems of digestive tract are frequent and the causal agents can be multiple and from diverse nature.

References: [1] Rzedowski J. y G. Rzedowski (1985). Flora Fanerogámica del Valle de México, Vol II, ENCB, IE, México. [2] Hernández del A. F. A., et al. (2000) Acta Cient. Potos. 15 (1): 40–53. [3] Pérez G. J. M. (2002) Actividad amebicida y antibacterial de cinco especies de la familia Asteraceae. Tesis de Licenciatura. Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, S. L. P. México, 39p