California poppy and Corydalis extracts prevented enzymatic breakdown of enkephalin pain-relieving peptides, suggesting a mechanism for traditional pain uses.
2 plant speciesCalifornia poppy and Corydalis both protected enkephalins from enzymatic breakdown
What the researchers found
Eschscholtzia californica and Corydalis cava extracts inhibited peroxidase- and tyrosinase-mediated dimerization and oxidation of enkephalin peptides.
Why it matters
These plants have long traditions in herbal medicine for pain and anxiety. This study provides a potential biochemical mechanism: protecting natural opioid peptides from breakdown.
How the study worked
In vitro assays measuring enzymatic dimerization and oxidation of met-enkephalin and leu-enkephalin in the presence or absence of plant extracts. Alkaloid content of extracts characterized.
What this study cannot tell us
In vitro study only. The plant extract concentrations tested may not be achievable in the body through oral consumption. Many other compounds in these extracts have their own effects.
How to read the evidence
Preliminary — in vitro enzyme inhibition study. Does not demonstrate that this mechanism operates in living organisms after oral consumption.
When this study was published
Published in 1995. Interest in natural enkephalinase inhibitors has continued, though clinical evidence for these specific plants remains limited.
The bigger picture
Rather than adding external opioids, these plants may work by protecting the body's own opioid peptides from breakdown — a fundamentally different approach to pain management that could have fewer side effects than opioid drugs.
Questions still open
- Can these plant extracts achieve protective concentrations in the brain after oral consumption?
- Which specific alkaloids in these extracts are responsible for the enkephalin-protecting effects?
Common questions
How might these plants reduce pain naturally?
Can I use these plants for pain relief?
Read the original research
Effects of ethanolic extracts from Eschscholtzia californica and Corydalis cava on dimerization and oxidation of enkephalins.
Arzneimittel-Forschung, 45(2), 132-6
Citation
Reimeier, C; Schneider, I; Schneider, W; Schäfer, H L; Elstner, E F. (1995). Effects of ethanolic extracts from Eschscholtzia californica and Corydalis cava on dimerization and oxidation of enkephalins.. Arzneimittel-Forschung, 45(2), 132-6.