AudioHelicase podcast: Treatments for COVID-19 taking root in plant science

Plants have been used as medicine for thousands of years; could they contribute to a solution to the COVID-19 pandemic? This is what Whitehead Institute Member Jing-Ke-Weng set out to address in a new paper, published May 20 in the journal Molecular Plant.  In this episode of AudioHelicase, we talked to Weng about an herbal treatment being used to treat COVID-19 in China derived from Traditional Chinese Medicine, the work necessary for such a treatment to be translated to an FDA-approved drug, and why the COVID-19 pandemic underscores the need for basic, fundamental research in plant science and beyond.

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EDITED TRANSCRIPT

Eva Frederick: Welcome to AudioHelicase, the podcast from Whitehead Institute where we unwind the science and the people behind some of the Institute’s most exciting discoveries. In the months since the novel coronavirus emerged, researchers across disciplines have come forward to offer their perspective on how best to deal with the virus. I’m Eva Frederick, a science writer at Whitehead Institute, and today I’ll be talking to Institute Member Jing-Ke Weng about one how one discipline you might not think of at first could play a role in stopping the pandemic. That discipline is plant science.

Jing-Ke Weng: My name is Jing-Ke Weng. I'm a member of the Whitehead Institute. I'm also associate professor of biology at MIT. My lab studies plant biochemistry and chemistry. I'm very interested in using plants for treating human diseases.

Frederick: Plants have been used as medicine for thousands of years.

Weng: There are many herbal remedies that have been independently developed by indigenous cultures around the world.

Frederick: Some of those plant remedies have informed key treatments we use today.

Weng: I would say there are two examples that are very well known. One is Artemisia annua, so this is a plant for treating malaria. So it's been used in China for thousands of years. But in the 1970s, Tu YouYou, a Chinese biochemist, discovered a molecule from the plant, artemisinin, now that's the standard therapy for treating malaria. The other one is quinine. So it's from the cinchona tree, which is native to South America, discovered in the 17th century. And then later on the quinine molecule was found from the tree also for treating malaria. So these are kind of two examples of how medicinal plants have been used for thousands of years and in the very recent centuries, we discovered magical molecules that can treat human diseases.

Frederick: Part of the research in Weng’s lab at Whitehead Institute focuses on exploring the chemistry of plants used in traditional Chinese medicine. After the first outbreaks of the virus surfaced in China, practitioners of Traditional Chinese Medicine began crafting treatments from medicinal herbs, drawing from recipes known to work for other ailments.

Weng: There are many recipes being developed, but successful experiences are quickly exchanged between hospitals, and eventually there are several prominent recipes being broadcasted nationwide.

Frederick: Notable among these recipes is a cocktail of 21 herbs called the “lung cleansing and detoxifying decoction,” or LCDD. The mixture is based on four formulae from an ancient book of herbal cures written in the second century AD, and contains herbs known for their decongestant and anti-inflammatory properties. The treatment was tested on a cohort of more than 1000 patients, including 57 people with severe symptoms. None of the people with mild symptoms developed a more severe case of COVID-19, and more than 99% of the cohort has recovered by now.

Weng: The overall efficacy and safety were remarkable, and I think it played a huge role for controlling the death rate in China. But the challenge for that is it's very cultural, so for a plant or herbal-based therapy to be transplanted out of China, there are a lot of hurdles. I think that the main hurdle is really the kind of the unknown nature behind these therapies. So these are a bunch of plants thrown together; for Chinese people, there's a cultural reason that people there can accept these types of therapies more than the rest of the world.

Frederick: That’s not to say Western medicine does not involve plant remedies. It does. But the ability to use these plant remedies in mass-produced drugs requires a solid foundation of knowledge about their chemical properties. The best tool to build this foundation, Weng says, is basic research.

Weng: As I mentioned before, there are a lot of unknowns. What are the molecules in these plants? And are they safe? Are they really efficacious? So to move forward, I think we need a lot of research into this area into the chemistry, biochemistry of these plants, the molecules that are present and how these molecules interact with that disease. So by understanding more of these mechanisms, we can then single out the molecules that actually work so we can make, let's say, define a composition of multiple compounds from plants. And maybe we'll also need to manufacture these molecules in a different way, so that's related to research in my lab -- we are trying to do biosynthesis instead of extraction from plants. So eventually, we will have a next generation of plant-inspired therapy, which have very defined chemical composition, and then run through very high standard FDA guided trials.

Frederick: When COVID-19 emerged, scientists were in a better position than ever before to fight an unknown pathogen.

Weng: Within a month, I think the genome was sequenced and there are a lot of diagnosis strategies that were developed. And there are many candidate drugs due to the previous investment into drug discovery now put into treatments for COVID-19. So that really speaks to the prior investment in science.

Frederick: But now, months into the pandemic, we are still moving toward an approved vaccine or a widespread treatment. In order to face future pandemics, Weng says, we will have to make that foundation even stronger.

Weng: I think that's a big lesson for us to learn. So in my mind in a post COVID-19 world, people realize that and invest a lot more into biomedicine, biology studies. So we can be much better prepared if another pandemic may hit in the next few years.

Frederick: In the meantime, Weng is planning ways to bring the medicinal properties of the lung cleansing and detoxifying decoction to Western medicine.

Weng: there are a few plants that are part of this LCDD therapy that have antiviral activities. We're interested in pursuing the chemistry and biochemistry of these molecules.

Frederick: This research, and further investigations into the chemical properties of plants, will help prepare researchers to tackle a wide variety of problems that may arise across the world in the coming years.

Weng: when I mentioned plant solutions for this particular COVID-19, or infectious diseases, it'll be studying medicinal plants and learning a lot more knowledge and these but how, what these plants can offer for treating human diseases. So these will be solutions for medicine. But in a kind of grander perspective, we're facing climate change, food security, where plants can do a lot. For example, if we can boost the plant productivity so we can provide more food or the plants can also fix carbon from the atmosphere. So I think nothing in my mind can compare to the power of plants to utilize the sunlight and do great things for mankind.

Frederick: That’s all for today. To learn more about Jing-Ke Weng’s research, you can visit the Whitehead Institute website. Stay tuned for future episodes of AudioHelicase by subscribing on SoundCloud and iTunes. Thanks for listening.