Zombie mushrooms could help develop new anti-viral medications and cancer drugs

Researchers are growing mushrooms that feed on other insects in a lab. The zombie mushrooms could help develop new antiviral and anticancer drugs.

Cordyceps fungi, a.k.a zombie mushrooms, excel at infecting and killing insects. It grows through an insect’s body, creating a network of filaments that commandeers the insect’s muscles. Once the insect’s body is completely depleted of nutrients, the fungus grows into fully-fledged fruiting bodies that sprout from the insect’s flesh, releasing spores that infect more individuals.

While all of this sound very gruesome, Cordyceps mushroom also has strong medicinal potential. It contains a bioactive compound, cordycepin, that could potentially be developed into powerful new antiviral medications and cancer drugs.

However, Cordyceps mushrooms don’t grow like other mushrooms. They are rare in the wild, and growing healthy mushrooms in the lab had been a challenge- until now.

In a study published today, Professor Mi Kyeong Lee of Chungbuk National University and her team, including Dr. Ayman Turk, have found a way to grow these elusive fungi in a lab without losing their potency.

Finding the right food

Usually, the mushrooms are grown in the labs on grains such as brown rice, but the levels of cordycepin produced by the mushroom are very low due to the grain’s low protein content.

To increase the yield of cordycepin, Lee and her colleagues experimented with edible insects as an alternative growth medium for Cordyceps. As different insects offer different nutritional values, the research team investigated the best meal for the mushrooms to grow.

The team cultured zombie mushrooms on crickets, silkworm pupae, mealworms, grasshoppers, white-spotted flower chafer larvae, and Japanese rhinoceros beetles for two months and then harvested them to investigate the results.

As suspected, different insect food resulted in striking growth differences in the mushrooms.

The Cordyceps grew largest on mealworms and silkworm pupae and least well on chafer larvae and grasshoppers. However, maximum growth didn’t necessarily correlate with the high levels of cordycepin. Although they didn’t grow as large, the Cordyceps grown on Japanese rhinoceros beetles produced the highest levels of cordycepin, 34 times more than those produced on silkworm pupae, the poorest performers.

“Cordyceps grown on edible insects contained approximately 100 times more cordycepin compared to Cordyceps on brown rice,” said Dr. Lee.

Fattening Cordyceps up

Upon further investigation, researchers found that the key to high levels of cordycepin production depends on the fat content of the insect rather than the protein content. Specifically, high levels of oleic acid may be necessary for cordycepin synthesis. Adding oleic acid to a low-performing insect food improved the production of cordycepin in the Cordyceps grown on it by 50%.

“Our research convincingly shows that a potential strategy for boosting cordycepin production in the growth of Cordyceps would be to use insects with high oleic acid content,” said Dr. Lee.

Although the use of “edible insects is not yet sufficient for scale-up to industrial level,” researchers hope that the study will lead to the development of a more economically viable way of producing cordycepin to fight devastating illnesses. Knowing what to feed these very hungry Cordyceps means we can harness their power in drug discovery to find future medicines.