Effects of pine pollen extracts on the proliferation and mRNA expression of porcine ileal cell cultures

Abstract

Masson pine pollen has been used in the traditional Chinese medicine for several hundred years and is attributed a variety of health promoting effects including effectiveness against disorders of the digestive system. But only in recent years some evidence has been found that pine pollen and its compounds do influence e.g. inflammatory activities in mice or mRNA expression profiles in piglets. At least apart of these effects have been attributed to the content of polyphenols in pollen.
In the present study different extracts of Pinus massoniana pollen were analyzed for their effects on cell proliferation and mRNA expression levels of selected genes. Cell proliferation was analyzed using an electronic cell impedance sensing technique and relative gene expression profiles were investigated using qRT-PCR. It was found that water and 50% ethanol extracts of Masson pine pollen at a concentration equivalent to 1 % unprocessed pollen decreased cell proliferation significantly (p<0.05 to p<0.01). A 100% ethanol extract only transiently delayed cell growth (p<0.05 to p<0.001). 80% methanol and hexane extracts had no effects on cell proliferation. At the same concentration only the 50% ethanol extract led to a significant up-regulation of the relative expression levels of the pro-inflammatory genes IL-6 and IL-8 and to a down-regulation of proliferation promoter cyclin A (p<0.05).
LC-ESI-ToF-MS was performed to get a first impression of the compounds that may be responsible for the effects observed. Distinct mass signals have been identified that can be found in the effective pollen extracts but not in 80% methanol or hexane extracts. A further identification of additional substances could not be performed yet.