Anti-inflammatory Effect of Low-Dose Anethole and Ibuprofen Combination Is Accompanied by Partial Prevention of Hepatic Metabolic Changes in Arthritic Rats.

Anethole (AN) is a natural compound that has attracted great scientific interest because of its numerous biological activities, including anti-inflammatory effects. However, these effects were obtained with high doses of AN, which may be one limitation of its therapeutic use. This study evaluated the effects of a low-dose AN and ibuprofen (IB) combination on inflammatory parameters in Freund's complete adjuvant-induced arthritis (AIA) and arthritis-induced hepatic metabolic changes. Holtzman rats were used and divided into groups: normal, AIA (control), arthritics treated with IB, arthritics treated with AN, and arthritics treated with AN + IB. The volume of the paws, the appearance of secondary lesions, and the number of synovial leukocytes were evaluated. Gluconeogenesis and ureagenesis from alanine were determined in the rat liver in isolated perfusion. The AN + IB (62.5 + 8.75 mg/kg) treatment exerted an inhibitory effect on inflammatory parameters and partially prevented hepatic metabolic changes that was similar to the effect of high-dose IB (35 mg/kg) and AN (250 mg/kg) treatment. This effect of the treatments on hepatic metabolism can be, partly at least, explained by the preservation of both the alanine aminotransferase (ALT) activity and the cytosolic NADH/NAD+ redox potential in the liver. Taken together, the data obtained provided evidence that the AN + IB combination at lower doses than AN and IB treatment alone had beneficial inhibitory potential for the treatment of AIA and attenuated metabolic changes in the liver. Graphical Abstract.

Fish oil preparation inhibits leukocyte recruitment and bands that characterize inflamed tissue in a model of phenol-induced skin inflammation: percutaneous penetration of a topically applied preparation demonstrated by photoacoustic spectroscopy.

Fish oil (FO) is a natural source of omega-3 fatty acids, with well-established beneficial effects in inflammatory diseases when FO is orally administered. This study investigated the effects of a topically applied FO preparation (FOP) on phenol-induced ear edema and evaluated the percutaneous penetration of FOP in ear tissue. After applying phenol, groups of mice received FOP on the ear. After 1 h, ear tissue was collected to determine the percent inhibition of edema, myeloperoxidase activity, and to perform photoacoustic spectroscopy (PAS). Treatment with FOP did not reduce edema, but reduced myeloperoxidase activity. The FOP decreased the area of bands that characterize inflamed tissue and penetrated into the tissue. These results indicated an inhibitory effect of FOP on leukocyte recruitment in phenol-induced ear edema. These data support the applicability of PAS as a non-destructive method for evaluating the inflammatory response, percutaneous penetration and antiinflammatory activity of compounds.

Fish Oil and Adjuvant-Induced Arthritis: Inhibitory Effect on Leukocyte Recruitment.

Fish oil, a rich source of n-3 fatty acids, has been studied for its beneficial effects in many diseases. Recent studies have shown the robust anti-inflammatory activity of fish oil (FO), when administered orally to rats, in models of acute inflammation. Herein, we investigated if treatment with fish oil preparation (FOP) could interfere with the recruitment of leukocytes into the joint cavity of arthritic rats. We also evaluated the effect of treatment on rolling behavior and leukocyte adhesion in vivo and on leukocyte chemotaxis in vitro. Treatment with FOP (75, 150, and 300 mg/kg) initiated on the day of induction of arthritis (day 0) and maintained for 21 days reduced the total number of leukocytes recruited into the joint cavity, the number of rolling and adhered leukocytes in arthritic rats, and leukocyte migration in response to stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP) and leukotriene B4 (LTB4). Together, our data provide evidence that FOP plays an important inhibitory role in the recruitment of leukocytes into the joint cavity of arthritic rats.

Effects of anethole in nociception experimental models.

This study investigated the antinociceptive activity of anethole (anethole 1-methoxy-4-benzene (1-propenyl)), major compound of the essential oil of star anise (Illicium verum), in different experimental models of nociception. The animals were pretreated with anethole (62.5, 125, 250, and 500 mg/kg) one hour before the experiments. To eliminate a possible sedative effect of anethole, the open field test was conducted. Anethole (62.5, 125, 250, and 500 mg/kg) showed an antinociceptive effect in the writhing model induced by acetic acid, in the second phase of the formalin test (125 and 250 mg/kg) in the test of glutamate (62.5, 125, and 250 mg/kg), and expresses pain induced by ACF (250 mg/kg). In contrast, anethole was not able to increase the latency time on the hot plate and decrease the number of flinches during the initial phase of the formalin test in any of the doses tested. It was also demonstrated that anethole has no association with sedative effects. Therefore, these data showed that anethole, at all used doses, has no sedative effect and has an antinociceptive effect. This effect may be due to a decrease in the production/release of inflammatory mediators.