Euphorbia fischeriana extract reactivates latent HIV through nuclear factor-κB pathway / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of Euphorbia fischeriana extract on latent HIV reactivation and the pathway involved in this process and discuss the value of Euphorbia fischeriana extract in eliminating HIV.</p><p><b>METHODS</b>Fresh tissues of Euphorbia fischeriana root were crushed into powder after quick freezing with liquid nitrogen and extracted with acetone followed by a three-day vacuum freeze-drying for dehydration of the extract. The extract (EFE) was separated using RP-C18 column with high-performance liquid chromatography (HPLC) and identified with mass spectrometry (MS). The activity of reactivated latent HIV was analyzed by fluorescence-activated cell sorting in a J-Lat 10.6 cell model treated with EFE (50 µg/mL) for 24 h, using TNF-α (10 ng/mL) as the positive control. The effect of a NF-κB pathway inhibitor (Bay 11-7082) on EFE activity was tested. The changes in P65 expression in the cell nuclei within 2 h and HIV protein p24 expression within 24 h were analyzed by Western blotting in cells treated with EFE.</p><p><b>RESULTS</b>EFE was obtained by one-step acetone extraction, and the concentration of prostratin in the extract was around 0.53 mmol/L. About 50% of the cells showed HIV reactivation after treatment with 50 µg/mL EFE for 24 h accompanied by a significantly increased p24 expression. The activity of EFE in reactivating latent HIV was inhibited by Bay 11-7082 in a concentration-dependent manner, and p65 accumulation was detected in the cell nuclei within 2 h.</p><p><b>CONCLUSION</b>EFE we obtained contains the active compounds of prostratin and its analogues and shows a strong capacity to reactivate latent HIV through classical NF-κB pathway.</p>