HIV-1 Replication Inhibition and Cytotoxicity with Increasing Concentrations of Lemon Juice, Lime Juice, and Vinegar in Cell-based Assays. CCR5-tropic cell-free HIV-1 entry assay (A), CCR5-tropic cell-associated HIV-1 transmission assay (B), CXCR4-tropic cell-free HIV-1 entry assay (C), CXCR4-tropic fusion assay (D), and PBMC antiviral assay (E). Virus growth (shown as % of virus control (VC), solid lines) and cell viability (shown as % viability of untreated cell control (CC), dashed lines) are presented for lemon juice, lime juice, and vinegar. Results are shown for both pH neutral (blue) and natural (red) formulations. Means ± standard deviations (SD) of replicate experiments are presented. The black, horizontal line indicates the level for 50% cell death (i.e., TC50) or 50% virus inhibition (i.e., IC50), respectively, for each assay. The number of experiments performed (n) is indicated within each figure for the pH neutralized (*) and the natural products (#). The concentration of juice or vinegar is expressed as percent (%) solution (v/v).