Anti-inflammatory activity of N-butanol extract from Ipomoea stolonifera in vivo and in vitro.

Ipomoea stolonifera (I. stolonifera) has been used for the treatment of inflammatory diseases including rheumatism and rheumatoid arthritis in Chinese traditional medicine. However, the anti-inflammatory activity of I. stolonifera has not been elucidated. For this reason, the anti-inflammatory activity of n-butanol extract of I. stolonifera (BE-IS) was evaluated in vivo by using acute models (croton oil-induced mouse ear edema, carrageenan-induced rat paw edema, and carrageenan-induced rat pleurisy) and chronic models (cotton pellet-induced rat granuloma, and complete Freund's adjuvant (CFA)-induced rat arthritis). Results indicated that oral administration of BE-IS significantly attenuated croton oil-induced ear edema, decreased carrageenan-induced paw edema, reduced carrageenan-induced exudates and cellular migration, inhibited cotton pellet-induced granuloma formation and improved CFA-induced arthritis. Preliminary mechanism studies demonstrated that BE-IS decreased the levels of myeloperoxidase (MPO) and malondialdehyde (MDA), increased the activity of anti-oxidant enzyme superoxide dismutase (SOD) in vivo, and reduced the production of nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 in lipopolysaccharide-activated RAW264.7 macrophages in vitro. Results obtained in vivo and in vitro demonstrate that BE-IS has considerable anti-inflammatory potential, which provided experimental evidences for the traditional application of Ipomoea stolonifera in inflammatory diseases

Short-Term Pretreatment of Sub-Inhibitory Concentrations of Gentamycin Inhibits the Swarming Motility of Escherichia Coli by Down-Regulating the Succinate Dehydrogenase Gene

Background/Aims: Motility is a feature of many pathogens that contributes to the migration and dispersion of the infectious agent. Whether gentamycin has a post-antibiotic effect (PAE) on the swarming and swimming motility of Escherichia coli (E. coli) remains unknown. In this study, we aimed to examine whether short-term pretreatment of sub-inhibitory concentrations of gentamycin alter motility of E. coli and the mechanisms involved therein. Methods: After exposure to sub-inhibitory concentrations (0.8 μg/ml) of gentamicin, the swarming and swimming motility of E. coli was tested in semi-solid media. Real-time PCR was used to detect the gene expression of succinate dehydrogenase (SDH). The production of SDH and fumarate by E. coli pretreated with or without gentamycin was measured. Fumarate was added to swarming agar to determine whether fumarate could restore the swarming motility of E. coli. Results: After pretreatment of E. coli with sub-inhibitory concentrations of gentamycin, swarming motility was repressed in the absence of growth inhibition. The expression of all four subunits of SDH was down-regulated, and the intracellular concentration of SDH and fumarate, produced by E. coli, were both decreased. Supplementary fumarate could restore the swarming motility inhibited by gentamycin. A selective inhibitor of SDH (propanedioic acid) could strongly repress the swarming motility. Conclusion: Sub-inhibitory concentrations of gentamycin inhibits the swarming motility of E. coli. This effect is mediated by a reduction in cellular fumarate caused by down-regulation of SDH. Gentamycin may be advantageous for treatment of E. coli infections

Effect of BE-IS on cotton pellet-induced granuloma in rats.

<p>With rats under ether anesthesia, sterile cotton pellets weighing 50±1 mg were implanted subcutaneously in both axillae regions of each rat by a single needle incision. Then rats were divided randomly into five groups: Control group (0.5% CMC-Na, p.o), Dexamethasone (DEX) group (2.5 mg/kg, i.p.) and BE-IS groups (100, 200, and 400 mg/kg, p.o). On day 8, granuloma tissue was carefully dissected. The pellets were incubated at 37°C for 24 h and dried at 60°C to constant weight. The increase in dry weight of the pellets was used to measure granuloma formation. Values are expressed as mean ± S.E., n = 10, *<i>P</i><0.05, **<i>P</i><0.01 as compared to the control group.</p

Effect of BE-IS on rat pleurisy induced by carrageenan.

<p>Each value represents as mean ± S.E., n = 10.</p><p>*<i>P</i><0.05,</p><p>**<i>P</i><0.01,</p><p>***<i>P</i><0.001 compared to control group.</p

Effect of BE-IS on the viability of RAW264.7 cells.

<p>Cells were incubated for 24% DMSO, 1 µg/ml LPS, or BE-IS (1.25, 2.5, 5, 10, 20 µg/ml, dissolved in 0.1% DMSO). Cell viability was determined by MTT assay. The optical density was measured at 550 nm on a microplate reader. Values are expressed as mean ± S.E. for three different experiments performed in triplicate.</p

Effect of BE-IS on ear edema (A) and MPO activity (B) induced by croton oil in mice.

<p>Mice were divided randomly into five groups: Control group (0.5% CMC-Na), Ibuprofen group (300 mg/kg) and BE-IS groups (150, 300, and 600 mg/kg). Ear edema was induced by topical application of 1% croton oil on the outer and inner surfaces of the right ear of each mouse. The left ear remained untreated and served as a control. Ear edema and MPO activity were measured 4 h after application of croton oil. Values are expressed as mean ± S.E., n = 20, *<i>P</i><0.05, **<i>P</i><0.01 as compared to the control group.</p

Effect of BE-IS on LPS-induced production of TNF-α (A), IL-1β (B) and IL-6 (C) in RAW264.7 cells.

<p>Cells were incubated with BE-IS (0, 1.25, 2.5, 5, 10, 20 µg/ml) for 1 h before stimulation with LPS (1 µg/ml) for 24 h. The concentrations of TNF-α, IL-1β and IL-6 in the cell supernatants were determined by ELISA according to the manufacturers’ instructions. Values are expressed as mean ± S.E. for three independent experiments. ^#<i>P</i><0.001 as compared to the control group, *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001 as compared to LPS-alone group.</p

Effect of BE-IS on complete Freund’s adjuvant-induced chronic arthritic rats.

<p>Each value represents as mean ± S.E., n = 10.</p><p>*<i>P</i><0.05,</p><p>**<i>P</i><0.01 compared to control group.</p

Effect of BE-IS on LPS-induced production of NO (A) and PGE₂ (B) in RAW264.7 cells.

<p>Cells were incubated with BE-IS (0, 1.25, 2.5, 5, 10, 20 µg/ml) for 1 h before stimulation with LPS (1 µg/ml) for 24 h. The concentrations of NO and PGE₂ in the cell supernatants were determined by the Griess reaction and ELISA, respectively, according to the manufacturers’ instructions. Values are expressed as mean ± S.E. for three independent experiments. ^#<i>P</i><0.001 as compared to the control group, *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001 as compared to LPS-alone group.</p