Plant Compound Shown to Inhibit HIV Reproduction

New research published in the Journal of Natural Products shows that a a plant compound can be more effective at suppressing HIV than azidothymidine (AZT, also called Zidovudine, and sold under the brand name Retrovir). Although AZT is no longer the go-to treatment it once was, it is still used as an ingredient in some combination therapies (Combivir, Trizivir) as well as in low income countries, and for poz folks fighting resistance to other HIV meds.  

AZT was the first drug approved to treat HIV in the early days of the AIDS epidemic. It works by inhibiting an enzyme HIV needs to “invade” a cell (a process called reverse transcriptase). At the high levels it was initially prescribed, AZT was eventually shown to be extremely toxic. But at much lower doses it has been an essential element of combination therapies.

The World Health Organization now recommends doctors first prescribe combination therapies using other drugs, but still recommends AZT in cases where other nucleoside reverse transcriptase inhibitors (NRTIs) are "contraindicated or not available." 

This makes the discovery of a plant that delivers similar effects without the damaging side effects a significant finding. A study, led by Lijun Rong, professor of microbiology and immunology at the University of Illinois College of Medicine, discovered that a chemical compound called “Patentiflorin A,” derived from a medicinal plant (Justicia gendarussa), found in East Asia, "was able to inhibit the action of reverse transcriptase much more effectively than AZT, and was able to do this both in the earliest stages of HIV infection when the virus enters macrophage cells, and alter infection when it is present in T cells of the immune system," noted Rong in theJournal of Natural Products.

The team enlisted their theories in a series of tests related to “tropism,” which refers to the kind of virus Patentiflorin A can invade: M-tropism for macrophages, and T-tropism for T cells. Both macrophages and T cells are white blood cells with key roles in immunity, Medical News Todaynotes. 

Rong also noted in the study that "if we can make the drug in the lab, we don't need to establish farms to grow and harvest the plant, which requires significant financial investment, not to mention it has an environmental impact." But, "Patentiflorin A represents a novel anti-HIV agent that can be added to the current anti-HIV drug cocktail regimens to increase suppression of the virus and prevention of AIDS."