1,098
Views
23
CrossRef citations to date
0
Altmetric
Research Article

Immunomodulatory effects of Pteridium aquilinum on natural killer cell activity and select aspects of the cellular immune response of mice

, , , , , & show all
Pages 104-114 | Received 08 Jan 2009, Accepted 08 Apr 2009, Published online: 10 Jul 2009
 

Abstract

Pteridium aquilinum (bracken fern) is one of the most common plants. Epidemiological studies have revealed a higher risk of certain types of cancers (i.e., esophageal, gastric) in people who consume bracken fern directly (as crosiers or rhizomes) or indirectly through the consumption of milk from livestock that fed on the plant. In animals, evidence exists regarding the associations between chronic bracken fern intoxication, papilloma virus infection, and the development of carcinomas. While it is possible that some carcinogens in bracken fern could be responsible for these cancers in both humans and animals, it is equally plausible that the observed increases in cancers could be related to induction of an overall immunosuppression by the plant/its various constituents. Under the latter scenario, normal tumor surveillance responses against nascent (non-bracken-induced) cancers or responses against viral infections (specifically those linked to induction of cancers) might be adversely impacted by continuous dietary exposure to this plant. Therefore, the overall objective of this study was to evaluate the immunomodulatory effects of bracken fern following daily ingestion of its extract by a murine host over a period of 14 (or up to 30) days. In C57BL/6 mice administered (by gavage) the extract, histological analyses revealed a significant reduction in splenic white pulp area. Among a variety of immune response parameters/functions assessed in these hosts and isolated cells, both delayed-type hypersensitivity (DTH) analysis and evaluation of IFNγ production by NK cells during TH1 priming were also reduced. Lastly, the innate response in these hosts—assessed by analysis of NK cell cytotoxic functionality—was also diminished. The results here clearly showed the immunosuppressive effects of P. aquilinum and that many of the functions that were modulated could contribute to the increased risk of cancer formation in exposed hosts.

Acknowledgments

The authors would like to thank Ms. Beatriz D. Caniceiro, Ms. Domenica P. Mariano-Souza, Mr. Alison Ribeiro and Mr. Ricardo M. Akinaga for their collaboration, Dr. Cristiane M. Gaitani and Dr. Marcos J. Salvador for the quercetin HPLC analysis and Dr. Paulo C. Maiorka for his assistance with the histopathological analyses. Andreia O. Latorre was supported by a fellowship from CAPES and FAPESP (Proc. 07/50313-4), Brazil.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.