Inhibitory effect of Hhypericum ascyron on pro-inflammatory responses in lipopolysaccharide-induced raw 264.7 cells

Hypericum ascyron has long been used as medicinal plant and recent studies reported that H. ascyron has anti-diabetic, anti-oxidant, and anti-bacterial effects. In this study, inhibitory effect from H. ascyron on pro-inflammatory responses has been investigated. H. ascyron was extracted at optimal extraction condition. Total phenolic contents in water and 90% ethanol were 29.75 and 31.82 mg/g, respectively. Hyaluronidase inhibitory activity of H. ascyron extracts (50-200 μg/mL phenolics) was 0.00-14.81% and 15.33-47.49%, respectively. In cell viability, cell toxicity was shown at concentration of 100 μg/mL and 30 μg/mL of water and 90% ethanol extract. Therefore, 10-50 μg/mL in water extracts and 5-20 μg/mL in ethanol extracts was selected each for further study. Inducible nitric oxide synthase (iNOS) derived nitric oxide (NO) and cyclooxygenase (COX)-2–derived prostaglandin E2 (PGE₂) protein expression inhibitory effect of extracts were inhibited in a dose dependent manner, significantly. Also, the pro-inflammatory cytokines inhibitory effect such as tumor necrosis factor-α, nterleukin (IL)-6 and IL-1β were decreased in the dose dependent manner. The results indicate that H. ascyron extracts reduced inflammatory responses in lipopolysaccharide- induced 264.7 cells via the regulation of the iNOS, COX-2, NO, PGE₂,and pro-inflammatory cytokines. Therefore, H. ascyron extracts have significant anti-inflammatory effect and a source as therapeutic materials.