Suppression of human immunodeficiency virus replication by ascorbate in chronically and acutely infected cells.
Level 5 - mechanism / opinion, no new human data
In vitro laboratory study with no human participants
PubMed 1698293 · doi:10.1073/pnas.87.18.7245
What was done
Researchers evaluated the in vitro effects of nontoxic concentrations of ascorbate (vitamin C) on HIV-1 replication, viral protein production, and syncytium formation in chronically and acutely infected human T-lymphocytic and CD4+ cell lines. They also measured reverse transcriptase (RT) activity and syncytium-forming ability following direct 1-day and 4-day incubation of cell-free virus with ascorbate (100 to 150 micrograms/ml) at 37 degrees Celsius.
What was found
In chronically infected cells, ascorbate reduced extracellular RT activity by greater than 99% and p24 antigen by 90% in culture supernatant, with no detectable negative effects on host cell viability, metabolic activity, or protein synthesis. In freshly infected CD4+ cells, ascorbate inhibited giant-cell syncytium formation by approximately 93%. Cell-free virus exposure to ascorbate for 1 day showed no effect, but 4-day exposure reduced RT activity by a factor of 3 to 14, compared to a 25- to 172-fold reduction observed in extracellular RT released from chronically infected cells.
Why it matters
This study identified in vitro antiretroviral activity of ascorbate through the suppression of viral protein synthesis and reduction of extracellular virion stability. It provides a laboratory baseline for potential mechanism-focused investigations.
Limits
The findings are derived entirely from cell-line cultures and cell-free viral preparations. No animal or human in vivo data were collected, and achievable physiological concentrations or clinical efficacy in humans cannot be established from this report.
Cited by
- contradicts An in vitro study found that incubating virus-infected cells for 4 days with 150 micrograms per milliliter of vitamin C reduced reverse transcriptase activity by 99% and p24 antigen levels by 13%.