A medicinal plant found in Asia and traditionally used to treat arthritis contains a potent anti-HIV compound more powerful than the drug AZT, scientists say. Azidothymidine (AZT) is an antiretroviral medication used to prevent and treat HIV/AIDS. The compound, patentiflorin A, is derived from the willow-leaved Justicia, and was identified in a screening of more than 4,500 plant extracts for their effect against the HIV virus. The willow-leaved Justicia extract had been taken from the leaves, stems and roots of plants that had been collected in Cuc Phuong National Park in Hanoi, Vietnam more than 10 years ago by Doel Soejarto, professor at the University of Illinois at Chicago (UIC) in the US. Researchers analysed the extract along with thousands of others as part of their efforts to identify new drugs against HIV, tuberculosis, malaria and cancer. They zeroed in on patentiflorin A because of its ability to inhibit an enzyme needed for HIV to incorporate its genetic code into a cell's DNA. AZT inhibits this enzyme, called reverse transcriptase.
In studies of human cells infected with the HIV virus, patentiflorin A had a much more significant inhibition effect on the enzyme. "Patentiflorin A 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," said Rong. "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. "If we can make the drug in the lab, we do not need to establish farms to grow and harvest the plant, which requires significant financial investment, not to mention it has an environmental impact," added Rong. The study was published in the Journal of Natural Compounds.