Mistletoe extract-induced effects on immunocompetent cells: in vitro studies

Area of Science:

• Immunology
• Phytochemistry

Background:

• Mistletoe extracts exhibit cytotoxic and immunomodulatory effects, influenced by host tree, processing, and composition.
• Fermented mistletoe extract from Viscum album L. on pine trees shows reduced cytotoxicity compared to other preparations.
• This specific extract has a very low content of mistletoe lectins.

Purpose of the Study:

• To investigate the immunomodulatory effects of a fermented mistletoe extract from pine trees.
• To analyze the impact of this extract on peripheral blood mononuclear cells (PBMC) from healthy, allergic, and colorectal tumor patients.
• To explore the involvement of immune cells and cytokine profiles in response to the mistletoe extract.

Main Methods:

• In vitro studies using fermented mistletoe extract from Viscum album L. grown on pine trees.
• Assessing cytotoxicity and immune cell stimulation of peripheral blood mononuclear cells (PBMC).
• Analyzing the involvement of CD4+ T helper cells, CD14+ monocytes/macrophages, and cytokine production (Type-1 and Type-2).

Main Results:

• The fermented mistletoe extract was less cytotoxic to PBMC compared to other preparations.
• The extract stimulated PBMC from healthy and allergic donors, with observed involvement of CD4+ T helper cells and CD14+ monocytes/macrophages.
• Type-1 and Type-2 cytokines were detected in approximately 20% of stimulated PBMC from healthy individuals, but showed reduced frequency in colorectal tumor patients.

Conclusions:

• The fermented mistletoe extract from pine trees demonstrates a favorable safety profile with significant immunomodulatory potential.
• The extract interacts with both specific (T helper cells) and non-specific (monocytes/macrophages) immune systems.
• Functional impairment of immunocompetent cells in colorectal tumor patients may be indicated by reduced cytokine responses.