Botanical supplement may weaken TB drug

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A widely used African botanical supplement, called Sutherlandia, may disrupt the effectiveness of a common anti-tuberculosis drug. This could in turn lead to the development of active tuberculosis and perhaps drug-resistant forms of the pathogen in some patients.

People around the world use botanical supplements to treat a wide range of physical and mental ailments. Some of these botanical supplements have high levels of antioxidants, which may have some positive health effects for certain conditions. However, the supplements and their antioxidants may have unwanted side effects when it comes to prescription medications.

For a new study, published in Neuromolecular Medicine, researchers monitored South African patients who were taking either Sutherlandia or a placebo, along with the world-standard anti-tuberculosis drug, Isoniazid. Sutherlandia is a supplement commonly taken in Africa to fight symptoms of infection and some chronic diseases, such as diabetes, and discovered that several patients taking the Sutherlandia supplement developed active tuberculosis despite taking Isoniazid.

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“We believe that the antioxidants in Sutherlandia can directly disrupt how Isoniazid functions within the body to prevent tuberculosis,” says William Folk, professor of biochemistry at the University of Missouri.

“Isoniazid is very reliable in preventing the active form of this potentially deadly microbe, which is present in nearly one-third of all humans, but if individuals concurrently take a botanical supplement, they could undo the good that the scientifically proven drug is accomplishing.

“More than one-third of the world’s population is susceptible to active tuberculosis, so it is unfortunate that Sutherlandia, which traditionally is taken to prevent or treat infections, can actually cause them to develop the disease, and perhaps also cause the microbe to become a drug-resistant ‘super bug.'”

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The findings could apply to many different botanical supplements and many different medications, including cancer-fighting drugs, so it’s important for future research to examine potential interactions between drugs and antioxidant-laden supplements, Folk says.

“With so many people around the world turning to botanical supplements to help with a wide range of health issues, it is vital that we explore how these supplements interact with established medical drugs.

“Many drugs use pathways that could be disrupted by antioxidants, so we need for physicians to better advise their patients. Many physicians do not know everything that their patients take, so it is important for people to inform their physicians, and for physicians to ask, so they can better advise their patients what is best for their health.”

The National Center for Complementary and Integrative Health, the Office of Dietary Supplements, and the University of Missouri funded the work. The contents are solely the responsibility of the authors and do not necessarily reflect the views of the sponsors.

Source: University of Missouri