Cytotoxic Effects of Gallic Acid and its Derivatives Against HIV-I-infected Microglia

ABSTRACT

In the previous study, we found that flavonoids and ginsenosides exhibited high eliminate rates of human immunodeficiency virus type 1 (HIV-1) D3-transfected macrophages. Based on these findings, here we synthesized the derivatives of gallic acid, including methyl gallate, methyl 4-O-methyl gallate, methyl 3,4-O-dimethyl gallate, and methyl 3,4,5-O-trimethyl gallate and measured their cellular toxic effects against HIV-1-infected macrophages. Of these, treatment with methyl 4-O-methyl gallate in the presence of lipopolysaccharide (LPS) and cycloheximide (CHX) most effectively eliminated HIV-1-transfected cytoprotective human microglial CHME5 cells and HIV-1-D3-infected human primary macrophages. Furthermore, these strongly inhibited LPS/CHX-induced phosphorylation of phosphoinositide 3-kinase (PI3K), pyruvate dehydrogenase lipoamide kinase isozyme 1 (PDK1), Akt, and glycogen synthase kinase-3β (GSK-3β) in the Tat-transfected cells and HIV-1-D3-infected human primary macrophages. These findings suggest that methyl 4-O-methyl gallate may be a promising candidate for eliminating HIV-1 infected macrophages by blocking PI3K/Akt signaling pathway.