Evaluation of anti-HIV-1 activity of a new iridoid glycoside isolated from Avicenna marina, in vitro.

This study was carried out to check the efficacy of methanol seed extract of Avicenna marina and its column chromatographic fractions on Peripheral Blood Mono nuclear Cells (PBMCs) toxicity and HIV-1 replication. The anti-HIV-1 activities of crude methanol extract and its fractions were performed by use of real-time polymerase chain reaction (PCR) assay and HIV-1 p24 antigen kit. A time of drug addiction approach was also done to identify target of anti-HIV compound. The activity of the extracts on CD4, CD3, CD19 and CD45 expression in lymphocytes population was performed by use of flow cytometry. The most active anti-HIV agent was detected by spectroscopic analysis as 2'-O-(4-methoxycinnamoyl) mussaenosidic acid. The apparent effective concentrations for 50% virus replication (EC50) of methanol extract and iridoid glycoside were 45 and 0.1 μg/ml respectively. The iridoid glycoside also did not have any observable effect on the proportion of CD4, CD3, CD19 and CD45 cells or on the intensity of their expressions on PBMCs. In addition, the expression level of C-C chemokine receptor type 5 (CCR5) and chemokine receptor type 4 (CXCR4) on CD4(+) T cells were decreased in cells treated with this iridoid glycoside. The reduction of these two HIV coreceptors and the result of time of addition study demonstrated that this iridoid glycoside restricts HIV-1 replication on the early stage of HIV infection.