The impact of highly active antiretroviral therapy by the oral route on the CD8 subset in monkeys infected chronically with SHIV 89.6P

Prophylactic and therapeutic effect of AZT/3TC in RT-SHIV infected Chinese-origin rhesus macaques

Background

The precise efficacy of nucleoside analogue reverse-transcriptase inhibitors (NRTIs) in preventing and inhibiting virus replication remains unknown in RT-SHIV infected Chinese-origin rhesus macaques (Ch RM).

Findings

Ch RM were inoculated intravenously with 200 TCID₅₀ RT-SHIV and treated by gavage with NRTIs (20 mg AZT and 10 mg 3TC twice per day) for four consecutive weeks beginning at one hour, on day 217 or 297 post inoculation, respectively. Treatment with AZT/3TC inhibited transiently RT-SHIV replication during chronic infection, but did not significantly affect peripheral blood CD4⁺ T cells in macaques. Treatment with AZT/3TC at 1 hour post infection prevented RT-SHIV infection in two out of four animals during the 120-day observation period.

Conclusions

Therefore, the Ch RM model with RT-SHIV infection can be used to evaluate the efficacy of new NRTIs.

Therapeutic effects of Nigella sativa on chronic HAART-induced hyperinsulinemia in rats

Prolonged use of highly active antiretroviral therapy (HAART) is associated with insulin resistance in HIV-1-positive patients. Small animal models that recapitulate the long-term effects of HAART may facilitate the identification of therapeutic agents to suppress these side effects. We investigated the protective effects of black seed oil (BSO) from Nigella sativa in Sprague-Dawley rats treated with a daily HAART regimen for 7 months. The antiretroviral drugs, consisting of nelfinavir (200 mg/kg), zidovudine (50 mg/kg), and efavirenz (20 mg/kg), were mixed with diet with or without BSO (400 microL/kg) supplementation. Significant increases in insulin and C-peptide levels were observed in HAART-treated groups, and concomitant BSO treatment reduced this hyperinsulinemia. Interestingly, HAART-treated rats showed reduced size of pancreatic islets that was not seen in BSO-exposed rats. In vitro studies showed that nelfinavir, alone and in combination with HAART, induced oxidative stress and decreased glucose-induced insulin production in INS-1 cells. Suppressed insulin production was restored in cells coexposed to either BSO or thymoquinone. Our findings demonstrated that chronic HAART may increase serum insulin levels by dysregulating both insulin production by beta cells and insulin action at the periphery. These deleterious effects may be prevented by dietary supplementation with BSO.