Abstract
Objectives: The objective of this study is to investigate the effects of Salviae Miltiorrhizae Radix hot aqueous extract on nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) production and on 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical scavenging in macrophages. Methods: Salviae Miltiorrhizae Radix (300 g) was heated at $100^{\circ}C$ with distilled water (2 L) for 4 hours. The extract was filtered and concentrated to 100 mL by using a rotary evaporator, was frozen at $-80^{\circ}C$, and was then freeze-dried by using a freezing-drying system. The RAW 264.7 macrophage was subcultured by using $10-{\mu}g/mL$ lipopolysaccharide (LPS). In order to evaluate cytotoxicity, we performed 3-(4,5-dimrthylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and measured the cell viability. The NO production was measured by using Griess assays, and the $PGE_2$ production was measured by using enzyme immunoassays. The antioxidant activity, the 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical scavenging capability, was measured by using the DPPH method. Results: Cell viability with the 1-, 5-, 25-, 125- and $625-{\mu}g/mL$ Salviae Miltiorrhizae Radix hot aqueous extract was not significantly decreased compared to the cell viability without the extract. When 125 and $625{\mu}g/mL$ of Salviae Miltiorrhizae Radix hot aqueous extract were used, nitric oxide (NO) production in LPS-stimulated RAW 264.7 macrophages was significantly inhibited compared to that in the control group. When 25, 125, and $625{\mu}g/mL$ of Salviae Miltiorrhizae Radix hot aqueous extract were used, $PGE_2$ production in LPS-stimulated RAW 264.7 macrophages was significantly inhibited compared to that in the control group. The 125- and $625-{\mu}g/mL$ Salviae Miltiorrhizae Radix hot aqueous extracts had high DPPH free-radical scavenging capabilities in RAW 264.7 macrophages. Conclusion: This study indicates that Salviae Miltiorrhizae Radix hot aqueous extract suppresses NO and $PGE_2$ production and improves DPPH free-radical scavenging capability. Thus, it seems that Salviae Miltiorrhizae Radix hot aqueous extract may have an anti-inflammation effect and antioxidant activity.