Glycoprotein isolated from Dioscorea batatas Decne modulates expressions of IL-4 and IL-10 in primary-cultured mouse lymphocytes.

In the present study, we investigated the anti-allergic activity of a glycoprotein isolated from Dioscorea batatas Decne (DBD glycoprotein, 30 kDa) on ovalbumin (OVA, 100 microg ml(-1))-induced T helper (Th) type-2 response in primary cultured mouse lymphocytes. Our results revealed that the DBD glycoprotein (200 microg ml(-1)) significantly attenuated the expressions of interleukin (IL)-4 and IL-10, whereas enhanced the expression of interferon (IFN)-gamma in OVA (100 microg ml(-1))-treated primary cultured lymphocytes. We also found that the DBD glycoprotein has inhibitory effects on phosphorylations of signal transducer and activator of transcription (STAT)-6, p44/42 mitogen-activated protein kinase (MAPK) and p38 MAPK in primary cultured lymphocytes. Interestingly, the DBD glycoprotein suppressed the transcriptional activation of GATA-binding protein 3 (GATA-3), whereas it enhanced the activity of t-box expressed in T cells (T-bet) in OVA-stimulated lymphocytes. The results from these experiments indicated that the DBD glycoprotein inhibits expressions of IL-4 and IL-10 through modulation of GATA-3, STAT-6, p44/42 MAPK and p38 MAPK in mouse lymphocytes. Therefore, we speculated that the DBD glycoprotein might be one component for preparation of nutraceutical health supplements for prevention of Th2 cell response-related immune disorder.