OBJECTIVELigusticum porteri is a traditional Native American herb. The roots of L. porteri are traditionally used in the treatment of many diseases, however, its cytotoxicity, antioxidative and immune-modulatory effects need to be investigated. In this study, we evaluated the effects of the root extract at different doses on human peripheral blood lymphocytes (PBLs).

METHODSThe lymphocytes were incubated with different concentrations of the root extracts (0, 50, 100, 200, and 400 μg/mL) and harvested every 6 h for 2 d (P<0.05). The protective effect of the herb against oxidative damage was determined by inducing oxidative stress with the administration of 50 μmol/L of hydrogen peroxide (HO).

RESULTSTreatments with L. porteri at 200 and 400 μg/mL increased the viability of PBLs. The deleterious effect of HOwas ameliorated by 400 μg/mL L. porteri treatment. Addition of 400 μg/mL L. porteri reduced lipid peroxidation in stressed PBLs by 94% (P<0.05). Treatment with 400 μg/mL of L. porteri resulted in a 26.4% increase of reduced glutathione levels. Activities of superoxide dismutase and catalase increased by 17.5% and 55.2% respectively, when stressed PBLs were treated with 400 μg/mL L. porteri for 2 d (P<0.05). Treatment with 400 μg/mL L. porteri increased interferon-γ and interleukin-2 expressions in HO-challenged PBLs (P<0.05), however, the root extract did not cause a significant difference in interleukin-10 levels compared to the control (P>0.05).

CONCLUSIONThe findings suggest that L. porteri might be a potential immune-modulating agent involving protective effects against oxidative damage.