Inhibition of prostaglandin E2 by substances derived from Wrightia pubescens latex in LPS-activated RAW 264.7 mouse macrophages

Abstract

Wrightia pubescens latex has been used as an anti-inflammatory and antinociceptive drug in traditional medicine. However, the mechanism involved in inflammation and pain of this plant is still unclear. Therefore, this study aimed to determine the inhibitory activity of substances derived from Wrightia pubescens latex (SWL) on prostaglandin E₂ (PGE₂) production and cyclooxygenase 2 (COX-2) expression in LPS-activated RAW 264.7 mouse macrophages. Various concentrations of SWL (10, 25, and 100 mg/mL) were used to treat LPS-activated RAW 264.7 mouse macrophages. PGE₂ level in cell culture supernatant was measured, while the protein extracted from cells was used to determine COX-2 expression by Western Blot analysis. The concentrations of PGE₂ in cell supernatant of most SWL treated groups were significantly reduced compared with LPS alone (P < 0.05), whereas COX-2 expression was reduced only in 100 mg/mL of SWL treated group. These results indicated the inhibitory activity of SWL on PGE₂ production and COX-2 protein expression in RAW 264.7 mouse macrophages which may lead to play a role in the reduction of inflammation and pain.