Comparative study of the anti-HIV activities of ascorbate and thiol-containing
reducing agents in chronically HIV-infected cells.
Am J Clin Nutr 1991 Dec;54(6 Suppl):1231S-1235S (ISSN: 0002-9165)
Harakeh S; Jariwalla RJ Viral Carcinogenesis Laboratory, Linus
Pauling Institute of Science and Medicine, Palo Alto, CA 94306.
To elucidate the action of vitamin C on pathogenic human retroviruses,
we investigated and compared the effects of noncytoxic concentrations
of ascorbic acid (AA), its calcium salt (Ca-ascorbate), and two thiol-based
reducing agents [glutathione (GSH) and N-acetyl-L-cysteine (NAC)] against
human immunodeficiency virus (HIV)-1 replication in chronically infected
T lymphocytes. Ca-ascorbate reduced extracellular HIV reverse transcriptase
(RT) activity by about the same magnitude as the equivalent dose of AA.
Long-term experiments showed that continuous presence of ascorbate was
necessary for HIV suppression. NAC (10 mmol/L) caused less than twofold
inhibition of HIV RT and conferred a synergistic effect (approximately
eightfold inhibition) when tested simultaneously with AA (0.426 mmol/L).
In contrast, nonesterified GSH (less than or equal to 1.838 mmol/L) had
no effect on RT concentrations and did not potentiate the anti-HIV effect
of AA. These results further support the potent antiviral activity of
ascorbate and suggest its therapeutic value in controlling HIV infection
in combination with thiols.