Related Experiment Videos
Toxic phorbol esters from Chinese tallow stimulate protein kinase C
G Brooks1, N A Morrice, C Ellis
1Department of Pharmacognosy and Pharmaceutical Chemistry, School of Pharmacy, University of London, U.K.
Summary
Phorbol esters from Chinese tallow seeds exhibit pro-inflammatory and protein kinase C activation properties. These findings highlight potential toxic hazards of Chinese tallow oil in industrial applications.
Area of Science:
- Natural Product Chemistry
- Toxicology
- Biochemistry
Background:
- Chinese tallow (Sapium sebiferum L. Roxb.) seeds contain phorbol esters.
- These compounds are structurally related to known pro-inflammatory and tumor-promoting agents.
Purpose of the Study:
- To isolate and characterize phorbol esters from Chinese tallow seeds.
- To evaluate the pro-inflammatory and protein kinase C (PKC) activating activities of these compounds.
Main Methods:
- Isolation and purification of phorbol esters from Sapium sebiferum seeds.
- Assessment of pro-inflammatory activity using an ear assay (ID50).
- Protein kinase C activation assays using purified mammalian brain enzyme (Ka).
Main Results:
- Several phorbol esters with tigliane nuclei were identified.
- Pro-inflammatory activity ranged from 0.042 to 2.6 nmoles per ear.
- PKC activation (Ka) ranged from 76-176 nM.
- A 4,20-dideoxy-5-hydroxy analogue was found to be inactive in both assays.
Conclusions:
- Isolated phorbol esters from Chinese tallow seeds possess significant pro-inflammatory and PKC activating potential.
- The 4,20-dideoxy-5-hydroxy analogue lacks these activities.
- Chinese tallow oil, used as a linseed oil substitute, may pose industrial toxicological risks due to these properties.