La Jolla researchers studying herbs and mushrooms in treating COVID-19

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Researchers at UC San Diego in La Jolla are among those undertaking studies assessing whether medicinal mushrooms and Chinese herbs can provide therapeutic benefit in treating COVID-19 infection.

The multi-center study is led by UCSD and UCLA, along with the La Jolla Institute for Immunology. It is among the first to evaluate the medicines using a randomized, double-blind, placebo-controlled clinical trial.

“We hope these treatments will reduce the need for hospitalization,” said principal investigator Dr. Gordon Saxe, director of research at the Centers for Integrative Health at UCSD School of Medicine.

Three trials are recruiting 66 to 80 patients who have tested positive for COVID-19 and are quarantined at home with mild to moderate symptoms.

One of the studies, which started in December and is slated to run until December 2022, tests the safety and feasibility of a 50/50 blend of the mushrooms agarikon and turkey tail in capsules.

According to Saxe, the mushrooms were chosen because of their long history of use and recent evidence of immune-enhancing and anti-viral effects.

In a study published in the March 2019 issue of Mycology, agarikon was found to inhibit viruses including influenza and herpes. Saxe said he believes medicinal mushrooms inhibit the viruses’ replication, a theory he plans to test in a Phase II trial against SARS-CoV-2, the coronavirus that causes COVID-19.

“Mushrooms have the advantage that they co-evolved with us,” Saxe said. “So bacteria, viruses and other fungi prey on mushrooms just like they prey on humans. And mushrooms have developed exquisite defenses against those
pests, and we believe they can confer those to us when we eat them.”

Another study, which began in July and is projected to end in December 2022, tests the safety and feasibility of a formulation of 21 Chinese herbs from Taiwan called Qing Fei Pai Du Tang that is widely used as a COVID-19 remedy in China.

The third ongoing trial measures whether the same medicinal mushrooms, given in capsules at the time of initial COVID-19 vaccination, can increase antibodies and other measures of immune response. It began in June and is scheduled for completion in June 2022.

Saxe said his team is close to beginning a fourth trial that will look at whether medicinal mushrooms could provide a lift similar to COVID-19 booster shots.

“Vaccines lead to the production of antibodies that can destroy the virus in the blood,” Saxe said. “Mushrooms may not only increase the number of these antibodies but also enhance T-cell immunity against virally infected cells.

“Further, because mushrooms bind to receptors on human immune cells, they can modulate our immunity, boosting it in some ways and calming it down in others. And this property of mushrooms may also reduce vaccine-related side effects.”

Natural therapeutics have been used for centuries to treat infectious diseases, Saxe said, noting that herbs have helped Chinese doctors manage 300 recorded epidemics, while Greek pharmacologist Pedanius Dioscorides prescribed agarikon to treat pulmonary infections 2,300 years ago.

Initial safety data from the trials are expected by the end of this year.

To learn more about or enroll in the trials, visit and search for “MACH-19.” ◆