Phytoprostanes

Phytoprostanes belong to a new family of prostaglandin-like compounds in plants that are formed from alpha-linolenic acid by a non-enzymatic pathway. Isoprostanes (isomers of prostaglandins) are formed from arachidonic acid in animals via an identical synthetic pathway. Little is known about the biological function of phytoprostanes in plant organisms.

When taken orally, phytoprostanes are probably poorly absorbed and rapidly metabolized, so that a systemic effect of phytoprostanes in the animal organism is not to be expected.

On the other hand, local contact of phytoprostanes with mucous membranes, irritation and immunological reactions could be induced.

For example, phytoprostanes can be detected in relevant amounts in pollen, such as birch pollen. In these pollen E1-phytoprostanes (structurally similar to prostaglandin E1) are found. These phytoprostanes are able to induce a Th-2-associated immune situation in humans.

1. Gilles S et al (2009) Pollen-derived E1-phytoprostanes signal via PPAR-gamma and NF-kappaB-dependent mechanisms. J Immunol 182:6653-6658.
2. Gutermuth J et al (2007) Immunomodulatory effects of aqueous birch pollen extracts and phytoprostanes on primary immune responses in vivo. J Allergy Clin Immunol 120:293-299.
3. Traidl-Hoffmann C et al (2005) Pollen-associated phytoprostanes inhibit dendritic cell interleukin-12 production and augment T helper type 2 cell polarization. J Exp Med 201:627-636.