Tea leaves have long been used in traditional Chinese medicine to help alleviate pain, but new research suggests they can also be used as a gateway to other drugs.
Researchers at the University of Oxford found that tea leaves were particularly potent in inhibiting opioid-like activity, as well as blocking the release of brain chemicals like serotonin and dopamine.
“Tea leaf was identified as an effective alternative to cocaine because it blocks the release from the brain of the opioids that cause opioid-related pain,” Dr. Richard Murray, a senior lecturer in psychology and neuroscience at Oxford University, told The Hill.
“But the mechanism by which tea leaf is effective at this is unknown.”
Dr. Murray and his colleagues used a variety of different methods to investigate the role of tea leaves in the opioid-releasing effects of cocaine.
For the first time, the researchers analyzed the chemical profiles of the drug in tea leaves.
They found that the compounds that are most abundant in tea leaf were related to opioids, but that the most potent of these was a substance called AMPA.
AMPA has been linked to both opioid and heroin addiction, and the compound can also inhibit dopamine, a neurotransmitter associated with reward.
The researchers also tested the effects of the compound in mice and rats, and found that it blocks an enzyme called AMPK that is essential for opioid signaling.
This means that the compound acts like an opioid blocker, which may help explain why the compound is often prescribed to people with chronic pain, Dr. Murray said.
The results of this study have been published in the journal Nature.
The study also looked at the effect of the tea leaf on mice, and discovered that the chemical composition of the leaf was similar to that of cocaine and heroin, leading the researchers to speculate that the tea leaves might be a “gateway” drug.
“It’s a plausible explanation, but the mechanism is not completely understood,” Dr Murray said in a statement.
“Our study provides further support for the theory that tea leaf might be an effective opioid-replacement medication.”
The study was funded by the National Institutes of Health and the UK’s National Institute for Health Research.
Dr. John G. Miller, a professor of pharmacology at the College of Medicine at Johns Hopkins University and a senior scientist at Johns’ Center for Research on Alcohol and Drugs, said he thought the study could help explain the drug’s opioid-inducing effects.
“The more common use of tea leaf has been to treat chronic pain and other medical conditions, but this is one of the few plants that has a powerful analgesic and is safe for people,” Dr Miller told The Associated Press.
“I think this paper will help us understand why the chemical profile of tea is similar to cocaine and other drugs.”
Dr Miller also said he was excited to find out more about the chemical structure of the compounds found in tea.
“We do not know exactly how these molecules are assembled,” he said.
“They may be differentially expressed in different parts of the body, and we do not yet know how this information will be used to design new medicines.”
The new research is the first to use the chemical compounds from tea to determine how they are metabolized.
Previous research by Dr. Miller and colleagues has found that cocaine is metabolized differently in mice than in humans.
In a previous study published in 2016, Dr Miller found that mice that received tea leaf orally were more likely to become addicted to the drug than mice that were not given the substance.
But Dr. Muhsin K. Al-Zubaidi, a scientist at the Center for Drug Discovery at the Johns Hopkins Bloomberg School of Public Health, said the new study did not support this theory.
“A lot of the work that we’ve done in this area has been based on animals,” Dr Al-zubaidisaid in a 2016 paper.
“Our findings suggest that tea is more active than we have previously thought.”
“Our results also suggest that cocaine, morphine, and opiates are metabolically similar to tea,” he added.
“There are a number of different ways to look at this, but I think the evidence is quite strong that the plant has the potential to be a very effective alternative treatment.”
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Alzubawise said he thinks tea leaves are a very promising avenue for pharmaceutical development.
“Many different research areas are currently looking at these compounds,” he told AP.
“I think it’s a really exciting time to be looking at them.”
The AP contributed to this report.