Leaves infusion of Pimenta pseudocaryophyllus (Gomes) Landrum is used in Brazilian folk medicine to treat the predisposition to arthritical and gouty affections of the joints, fever and other diseases. A refreshing drink prepared with the specie is also used due to its diuretic, sedative and aphrodisiac actions.
The study was undertaken to investigate the mechanisms of anti-hyperuricemic effect and anti-inflammatory activity of P. pseudocaryophyllus extracts.
Anti-hyperuricemic effect was investigated using xanthine oxidase assay and uricosuric studies with rats in which hyperuricemia was induced by potassium oxonate and uric acid. Anti-inflammatory activity was investigated on MSU crystal-induced paw edema model. Ethyl acetate extracts of the leaves (EAL) and branches (EAB), ethanolic extracts of leaves (EEL) and branches (EEB) and aqueous extracts of leaves (AL) and branches (AB) were evaluated.
The extracts of P. pseudocaryophyllus evaluated showed expressive results regarding the inhibition of xanthine oxidase enzyme in vitro and they were also able to reduce serum uric acid levels in hyperuricemic rats. The investigation of the mechanism of action, it was found that EAL, EAB, EEB, AB (125 and 250 mg/kg) and AL (250 mg/kg) promoted an increase on the urinary excretion of uric acid and EEL, EEB, AB (125 and 250 mg/kg) and EAB (250 mg/kg) were capable to inhibit liver xanthine oxidase. Treatments with EEL (125 and 250 mg/kg) and EEB (250 mg/kg) were able to reduce edema at 48 th h. EAL and EAB (125 and 250 mg/kg) showed significant anti-inflammatory activity on monosodium urate crystal-induced paw edema model at all evaluated times.
The specie P. pseudocaryophyllus showed remarkable anti-hyperuricemic effects through uricosuric effects and inhibition of xanthine oxidase and therefore can be considered as a promise in the treatment of diseases related to hyperuricemia. Moreover, ethyl acetate extracts had significant anti-inflammatory activity.