Lipopolysaccharide-induced effects of tricin on inflammatory and lacto-protein gene expression in bovine mammary epithelial cells

The aim of this study was to examine the lipopolysaccharide (LPS)-induced effects of tricin on inflammatory and lacto-protein gene expression in bovine mammary epithelial cells (BMECs). The BMECs were divided into four treatment groups. The BMECs were cultured in the medium without LPS(L) and tricin(T). The BMECs in groups L and L+T were treated with 1 μg·mL-1 of LPS without tricin, or with 10 μg·mL-1 of tricin, respectively. The BMECs in group T were cultured in the medium with 10 μg·mL-1 tricin. The results showed that the viability of cells was reduced significantly in the L treatment group (P<0.05), whereas cell viability was increased significantly in the T treatment group (P<0.01). The activity of superoxide dismutase(SOD) in the T treatment group was significantly higher than that of the L treatment group (P<0.01), but the contents of NO and malondialdehyde(MDA) showed the opposite results. The relative expression of IL-1β, IL-6, TNF-α, TLR2, TLR4, and MyD88 was elevated by LPS (P<0.01), whereas tricin supplementation reduced the relative expression of IL-1β, TNF-α, TLR2, and TLR4 in cells induced by LPS (P<0.01). The relative expression of JAK2, STAT5, mTOR, 4EBP1, and S6K1 in the T treatment group increased significantly (P<0.01), but the relative expression of CAT1 decreased significantly (P<0.01). LPS significantly reduced the relative expression of CAT1, LAT1, STAT5, mTOR, and 4EBP1 (P<0.01 or P<0.05), whereas tricin supplementation significantly increased the relative expression of STAT5 in cells induced by LPS (P<0.01). In conclusion, tricin increased the viability of BMECs and promoted lacto-protein gene expression in cells cultured in a medium without LPS. LPS elevated inflammatory gene expression and inhibited lacto-protein gene expression in BMECs. Tricin inhibited inflammatory gene expression; however, it did not improve lacto-protein gene expression in BMECs inhibited by LPS.