Recently, Dr. Ruth Brack-Werner presented a seminar to the Natural Products Scientific Interest Group (SIG) at NIH. A scientist at the German Research Center for Environmental Health in Neuherberg, Germany, she is developing anti-human immunodeficiency virus (HIV) drugs and other antiviral drugs from natural sources. Dr. Brack-Werner and her team are especially interested in investigating natural products that are sold as herbal medicines or dietary supplements for two reasons: some have clinical and safety information available, and some are known to have activity against viruses.
Her group developed a screening method called EASY-HIT (for exploratory assay system for the discovery of HIV inhibitors) that uses a HeLa cell line—engineered to express the genes for two HIV proteins that represent different stages of the viral replication cycle—as well as a red fluorescent reporter gene. Substances can be screened for inhibitory activity against HIV and according to whether they inhibit early or late stages of the viral replication cycle.
These researchers have screened more than 25,000 compounds so far with the method, and have also identified some novel anti-HIV agents—including a natural product that has high activity and new mode of action, an extract from the marine brown alga Lobophora variegata that inhibits HIV when it enters cells, and an extract from the South African medicinal plant Pelargonium sidoides that inhibits the attachment of HIV to cells. Dr. Brack-Werner’s laboratory has also focused on another medicinal plant that grows in the Mediterranean region that may have anti-HIV activity. Efforts are underway to isolate the most active fractions of this plant.
I’m intrigued by the research that Dr. Brack-Werner and her group are doing. Their research illustrates the great potential of natural products to help solve some of our toughest medical challenges.