In-vitro Wound Healing Effect of 15-Hydroxyprostaglandin Dehydrogenase Inhibitor from Plant

BACKGROUND: Prostaglandins (PGs) have short existence in vivo because they are rapidly metabolized by NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH) to 15-ketoprostaglandins. Inhibition of 15-PGDH causes elevated level of PGE(2) in cellular system. It will be valuable for the therapeutic management of diseases requiring elevated PGE(2) levels, like wound healing. OBJECTIVE: Ninety-eight plant samples were screened for the discovery of potent 15-PGDH inhibitor. Among them, top five plant extracts as potent 15-PGDH inhibitor were chosen to determine PGE(2) release from HaCaT (Keratinocyte cell line) cell line. Finally, top 15-PGDH inhibitor was selected to evaluate in vitro wound healing effect on HaCaT scratch model. METHOD: The inhibitory activity for 15-PGDH inhibitors was evaluated using fluorescence spectrophotometer by measuring the formation of NADH at 468 nm following excitation at 340 nm. Cell viability assay and PGE(2) release was evaluated in HaCaT cell line after treatment of 15-PGDH inhibitors. Scratches were made using sterile 200 μL on HaCaT cell and wound-healing effect was evaluated after treatment of 15-PGDH inhibitor. RESULTS: 15-PGDH inhibitors elevated PGE(2) levels in concentration-dependent manner. Ethanol extract of Artocarpus heterophyllus (EEAH), the most potent 15-PGDH inhibitor (IC(50) = 0.62 µg/mL) with least cytotoxicity (IC(50) = 670 µg/ml), elevated both intracellular and extracellular PGE(2) levels. EEAH facilitated in-vitro wound healing in a HaCaT (Keratinocyte cell line) scratch model. CONCLUSION: EEAH might apply to treat dermal wounds by elevating PGE(2) levels via COX-1 induction and 15-PGDH inhibition. SUMMARY: Biological inactivation of 15-PGDH causes elevated level of PGE(2) which will be useful for the management of disease that requires elevated level of PGE(2). Abbreviations used: 15-PGDH: 15-hydroxyprostaglandin dehydrogenase, COX: Cyclooxygenase, DTT: Dithiothreitol, DMEM: Dulbecco's modified Eagle's media, EEAH: Ethanol extract of Artocarpus heterophyllus, MRP4: Multidrug resistance 4, PGs: Prostaglandins, PGT: Prostaglandin transporter, SDS: Sodium dodecylsulfate