Hypericum ascyron has been used for medicinal plant and recent studies have reported that H. ascyron has anti-diabetic, anti-oxidant and anti-bacterial effects. There is no study about H. ascyron for anti-inflammatory mechanism. We have investigated whether H. ascyron has potential inhibitory effect on pro-inflammatory responses or not.
H. ascyron was extracted at optimal extraction condition. Total phenolic compounds contents in water and 90% ethanol were 29.75, 31.82 mg/g, respectively. Anti- inflammatory activities of H. ascyron extracts were investigated by measuring hyaluronidase inhibition, cell viability, Nitric oxide (NO) and inducible nitric oxide synthase (iNOS), Cyclooxygenase-2 (COX-2) expression by western blotting and prostaglandin E2 (PGE2), and pro-inflammatory cytokines (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β)) by ELISA in lipopolysaccharide (LPS)-stimulated Raw 264.7 cells.
In result, hyaluronidase inhibitory activity of H. ascyron extracts (50~200 phenolic ㎍/mL concentration) was determined 0.00~14.81%, 15.33~47.49% on hyaluronidase inhibition, respectively. Cell viability showed that water and ethanol extract was not cytotoxic to Raw 264.7 cell at concentrations up to 50 ㎍/mL and 20 ㎍/mL, respectively.
We selected the water and ethanol extracts concentration of 10, 20, 30, 50 ㎍/mL and 5, 10, 20 ㎍/mL for further study. In NO production, water and ethanol extracts were approximately inhibited 88.30% and 71.5% each at the high concentration. Extracts inhibited the release of NO in a dose dependent manner, significantly. iNOS-derived NO protein expression inhibitory effect of extracts was determined 50.00%, 58.00% at high concentration. PGE2 production was decreased up to 83.00%,93.00%. COX-2–derived PGE2 protein expression inhibitory effect of extracts was decreased up to 50.00%, 33.00%. The pro-inflammatory cytokines inhibitory effect such as TNF-α, IL-6 and IL-1β were decreased in the dose dependent manner.
The results indicate that H. ascyron extracts reduced inflammatory responses in LPS-induced 264.7 cells via the regulation of the iNOS, COX-2, NO, PGE2 and pro-inflammatory cytokines. Therefore, these results suggest that extracts of H. ascyron may have significant effects on inflammatory factor and may be a potential anti-inflammatory as therapeutic materials.