Oxidative stress is implicated in HIV-infection. It has been suggested that plant antioxidants may offer protection from viral replication and cell death associated with oxidative stress in patients with HIV/AIDS. Because of inherent antioxidant properties of turmeric (T) and its derivatives, water-soluble extract turmerin (Tm) and lipid soluble curcumin (Cu), their potential efficacy as anti-HIV drugs were examined. Cell viability and p-24 antigen release by CEMss-T cells (1 x 10(5) cells/ml) infected with HIV-IIIB strain, used as an acute model of infection, were tested in the presence of 3' azido-3' deoxythmidine (AZT). Proliferative responses of human mononuclear cells derived from HIV patients ( chronic model) stimulated with phyohemagglutinin (PHA), concanavalin A ( ConA), and pokeweed mitogen (PWM) were also examined in the presence of AZT and Tm. In the infection assay, T, Tm and Cu individually did not reduce p-24 antigen release or improve cell viability. AZT (5 muM) + Tm (800 ng/ml) inhibited infection by 37% and increased cell numbers by 30%; whereas, Tm (80 ng/ml) inhibited infection by 26% and increased cell number by 60%. In the proliferation assay, lymphocytes from HIV-infected patients showed better inhibition of mitogen responsiveness to Tm ( 800 ng/ml) when compared to AZT at 5 muM or Tm at 80 ng/ml. Turmerin inhibited HIV-infected T-cell proliferation and, in combination with AZT, decreased T-cell infection and increased cell viability. These data provide evidence suggesting that efficacious anti-HIV therapy may be possible using lower, less toxic doses of AZT in the presence of turmerin.