Perilla defatted seed extract has very low toxicity. After administering 2000 mg/kg to mice for 2 weeks, no toxic effects were observed (LD50 for mice is therefore more than 2000 mg/kg). Dosage of 7.0 g/kg for 2 weeks did not produce any toxic effects in humans.
In Japan, 20-50% of long-term workers in the perilla industry develop dermatitis on their hands due to contact with perillyl aldehyde.
A 13-week subchronic oral toxicity study of perilla leaf extracts in drinking water did not show any acute toxicity. There were no treatment-related changes in body weight gain or in haematological or blood biochemistry values. Nor were there any treatment-related histopathological changes observed in the highest dose group.
There has been a report of lipoid pneumonia in a 57-year-old man who had a history of ingesting green perilla oil, and there was also residual neurologic deficit of cerebral infarction with right hemiparesis.
Phase I and II clinical trials of perillyl alcohol for certain cancers have shown that gastrointestinal side-effects and fatigue are the most common adverse reactions. Gastrointestinal effects are usually mild and include nausea, vomiting, bloating and belching. Doses were usually between 1200 and 1600 mg/m2 four times daily.
The refined perilla oil is clear golden yellow. It is fully refined (neutralised, bleached and deodorised) and should be free of perillyl ketone, which is a potent lung toxin that causes increased microvascular permeability and pulmonary oedema in grazing animals.
Controlled studies are not available, so interactions are based on evidence of activity and are largely theoretical and speculative.
Theoretical additive effect is possible. Patients taking perilla concurrently with antihistaminic should be observed and drug doses modified if required.
Contraindications and Precautions
None reported for perilla seed extract or refined oil; however, perilla leaf extract is contraindicated in diarrhea.
Insufficient information is available to determine the safety of perilla during pregnancy.