Effect of sodium glycyrrhetinate on chemical peritonitis in rats.
AIM
To study the anti-inflammatory mechanisms of sodium glycyrrhetinate (SG).


METHODS
Rat chemical peritonitis was used. The protein content and prostaglandin E2 (PGE2) content in exudate were measured by Folin-phenol assay and RIA, respectively. SOD activity in neutrophils (Neu) was determined by pyrogallol-NBT colorimetry. cAMP content in Neu was detected by competitive protein binding assay.


RESULTS
In peritonitis caused by histamine, SG 10-20 mg.kg-1 i.m. reduced exudate volume and Neu counts, and 5-20 mg.kg-1 i.m. lowered the protein content in exudate. In peritonitis induced by carrageenan, SG 20 mg.kg-1 i.m. reduced exudate volume, Neu counts, protein content and PGE2 content in exudate, increased SOD activity in Neu, but did not affect beta-glucuronidase release from Neu. In peritonitis induced by arachidonic acid, SG 20 mg.kg-1 i.m. reduced Neu counts, protein content, and PGE2 content in exudate, and attenuated the reduction of cAMP level in Neu.


CONCLUSION
SG exerts its anti-inflammatory action by lowering permeability of capillaries in inflammatory site, inhibiting Neu emigration and PGE2 biosynthesis, and scavenging oxygen free radicals.