Anti-Oxidant Activity and Anti-Inflammatory Effects of Rhododendron lapponicum (L.) Wahlenb. var. parvifolium (Adams) Herder Extract
Background : We studied the anti-oxidant activity and anti-inflammatory effects of Rhododendron lapponicum (L.) Wahlenb. var. parvifolium (Adams) Herder extract (RLE). Methods and Results : The RLE was prepared using methanol. The antioxidant effects of RLE was evaluated for its DPPH (1,1-diphenyl-2-picrylhydrazyl) free-radical scavenging activity, reducing power. Subsequently, using the RAW 264.7 cells, the cell viability of RLE was evaluated with or without LPS (lipopolysaccharide), and the anti-inflammatory effects of RLE was also estimated by nitric oxide (NO) and using real-time polymerase chain reaction (RT-PCR). The extract showed antioxidant activity (DPPH free-radical scavenging activity) with RC50 value of 57.67 ㎍/㎖. The reducing power of the extract was Abs 0.77 at 250 ㎍/ ㎖. The result indicated that RLE would have significantly high anti-oxidative effects. Cell viability was determined using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. To evaluate anti-inflammatory activity, we examined the inhibitory effects on LPS-induced NO production in RAW 264.7 cells. The NO inhibition rate was 85.44% at 200 ㎍/㎖ RLE. At the same concentration, the expression of pro-inflammatory genes such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 also decreased. In RLE 50 ㎍/㎖ concentration showed the highest decrease. Conclusion : This result suggest that RLE is a novel resource for the development of foods and drugs that possess anti-oxidant and anti-inflammatory activity. Also, RLE can be developed as an inflammatory agents for cosmetic bases in the future.