Effect of kramecyne on the inflammatory response in lipopolysaccharide-stimulated peritoneal macrophages

Abstract

Kramecyne is a new peroxide, it was isolated from Krameria cytisoides, methanol extract, and this plant was mostly found in North and South America. This compound showed potent anti-inflammatory activity; however, the mechanisms by which this compound exerts its anti-inflammatory effect are not well understood. In this study, we examined the effects of kramecyne on inflammatory responses in mouse lipopolysaccharide- (LPS-) induced peritoneal macrophages. Our findings indicate that kramecyne inhibits LPS-induced production of tumor necrosis factor (TNF- α ) and interleukin- (IL-) 6. During the inflammatory process, levels of cyclooxygenase- (COX-) 2, nitric oxide synthase (iNOS), and nitric oxide (NO) increased in mouse peritoneal macrophages; however, kramecyne suppressed them significantly. These results provide novel insights into the anti-inflammatory actions and support its potential use in the treatment of inflammatory diseases.

Figure 1

Effect of kramecyne on cell viability in peritoneal macrophages. Peritoneal macrophages were treated with kramecyne at 31.25, 62.5, 125, and 250 μg/mL in the presence or absence of 1 μg/ml LPS for 24 hrs. Cell viability was examined with violet crystal. Results are expressed as the percentage of surviving cells relative to control cells. Date represent mean ± SEM of three independent experiments; each was performed in triplicate.

Figure 2

Effect of kramecyne on NO production in peritoneal macrophages LPS stimulated. The Griess reagent assay was carried out to measure nitrite produced as described in the materials and methods. Date represent mean ± SEM of three independent experiments performed in triplicate; **P < 0.05 versus basal and kramecyne group; *P < 0.05 versus LPS group.

Figure 3

Effect of kramecyne on LPS-induced mRNA expression of (a) iNOS, (b) COX-2, (c) TNF-α, and (d) IL-6 in peritoneal macrophages. Total RNA (1 μg) was prepared and analyzed by RT-PCR, as described in the material and methods. Date represent mean ± SEM of three independent experiments; **P < 0.05 versus basal and kramecyne group; *P < 0.05 versus LPS group.

Figure 4

Inhibitory effect of kramecyne on the (a) TNF-α and (b) IL-6 cytokines production in peritoneal macrophages. Concentration in the supernatants was determined by ELISA. The results are the mean values ± SEM for five independent experiments; **P < 0.05 versus basal and kramecyne group; *P < 0.05 versus LPS group.