Investigation of the cytotoxicity, antioxidative and immune-modulatory effects of Ligusticum porteri (Osha) root extract on human peripheral blood lymphocytes.

OBJECTIVE: Ligusticum 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).

METHODS: The 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 (H2 O2 ).

RESULTS: Treatments with L. porteri at 200 and 400 μg/mL increased the viability of PBLs. The deleterious effect of H2 O2 was 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 H2 O2 -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).

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