The Effects of Thai Herbal Ha-Rak Formula on COX Isoform Expression in Human Umbilical Vein Endothelial Cells Induced by IL-1β

OBJECTIVE: To investigate the modulated effects of HRF on cyclooxygenase isoform expression and its activity, using the human umbilical vein endothelial cell (HUVEC) model induced by interleukin-1 beta (IL-1β). METHODS: Cells were treated with indomethacin (positive control), HRF, and its components at various concentrations prior to treatment with IL-1β at 24 h. Cell viability was determined by MTT assay. Moreover, the anti-inflammatory effects of HRF and its components through mRNA and protein expression were established using real-time quantitative PCR and Western blot, respectively. COX activity was identified via exogenous and endogenous PGE(2) productions using the EIA. RESULT: There was no cytotoxicity in HUVECs treated with HRF. None of the experimental conditions used in the study affected the expression of COX-1, but COX-2 protein expression was inhibited at concentrations under 10 µg/mL. Despite the significantly increased levels of exogenous PGE(2), HRF had no effect on COX-2 mRNA expression. However, the production of PGE(2) was lower at a concentration of 100 µg/mL HRF than at a concentration below 10 µg/mL. Interestingly, each component of HRF revealed different effects of the Ha-Rak formula. CONCLUSION: Our preliminary findings suggest that HRF and its components provide diverse modulation of COX-2 and PGE(2) at the in vitro level.