The anti-inflammatory effects of Taraxacum mongolicum (TM) were investigated in Holstein-Friesian dairy cows, in vitro and in vivo. In vitro, isolated milk somatic cells were pretreated with various concentrations (31 to 500, μg/ml) of TM extract (TME) and subsequently incubated with lipopolysaccharide (LPS, 1 μg/ml). The results show that TME treatment had no effect on cell viability; however, it significantly suppressed LPS-induced expression of nitric oxide (NO), interleukin(IL)-8, IL-1β, and tumor necrosis factor (TNF)-α in milk somatic cells, in a dose-dependent manner. In vivo, 14 lactating Holstein-Friesian cows, with subclinical mastitis, were randomly assigned to two groups and fed a diet with (treatment group, n=7, 150 g TM powder per head per day) or without (control group, n=7) TM supplementation for 14 days. Cows fed with TM powder had a significantly (P<0.05) reduced somatic cell count, total bacteria count and IL-8 in milk compared to the control group. In conclusion, the anti-inflammatory effects of TM were associated with down-regulation of NO and pro-inflammatory cytokines. Addition of TM as a dietary supplement might minimize the impact of subclinical bovine mastitis.

Key words: Cytokine, mastitis, somatic cell count, Taraxacum mongolicum,traditional Chinese medicine.