Activation of intestinal immune system by an orally administered methanol extract from pine needles

Abstract

When pine (Pinus densiflora) needles were fractionated into cold water (PD-CW), hot water (PD-HW) and methanol extract (PD-M), PD-M showed potent simulating activity (1.19-fold of the saline control) for proliferation of bone marrow cells mediated by Peyer's patch cells in vitro. MeOH extracts were prepared by homogenization, stirring or reflux to identify the method of methanol extraction, and MeOH extract by reflux method showed significantly highest intestinal immune system modulating activity (1.30-fold) in vitro. The intestinal immune system modulating effect of orally administered PD-M fractionated from pine needles also were studied in mice. Analyzing intestinal immune system modulating activity mediated Peyer's patch cells from C3H/He mice which had been fed with PD-M at different doses for 7 days, 1.0 g/kg of BW/day indicated that the bone marrow cells had proliferated (3.65-fold of 3% EtOH administered group). In addition, the amounts of IL-6 in the culture supernatant of Peyer's patch cells at 1.0 g/kg of BW/day were increased (1.13-fold) whereas the production of GM-CSF was not dose dependent. These results indicate that oral administration of PD-M enhances the secretion of hematopoietic growth factors such as GM-CSF and IL-6 from Peyer's patch cells, and these cytokines also act on modulator of bone marrow cell proliferation.