The effect of aerosolized indomethacin on lung inflammation and injury in a rat model of blunt chest trauma

Indomethacin Combined with Ciprofloxacin Improves the Prognosis of Mice under Severe Traumatic Infection via the PI3K/Akt Pathway in Macrophages

The prevention and treatment strategies for traumatic infection often focus on the use of antibiotics, while eschew the combined treatment of the bacteria, their toxins, and inflammatory mediators. This might be a main reason the prognosis of wound victims has not improved. Although our previous work found that the combination of indomethacin (IND) and ciprofloxacin (CIP) could promote skin wound repair and enhance the immune function, the efficacy and safety of this strategy for severe traumatic infection-mediated complications remain unknown. Additionally, there is no study on the relevant target cells and molecular mechanisms. In this study, C57BL/6 adult male mice were modeled for severe traumatic infection, and the optimal doses of IND and CIP alone were determined. After that, the efficacy and safety of IND plus CIP in traumatic infection mice were explored. Then the differentially expressed genes of activated macrophages in this process were analysed and verified by transcriptomic methods and conventional experimental techniques. The role of a candidate signalling pathway (PI3K/Akt) in regulating macrophage function and drug combination therapy was evaluated. The results showed that IND plus CIP increased the survival rate, reduced the degree of inflammatory response, and enhanced the bacteriostatic effect in mice under traumatic infection. This combined therapy did not cause significant damage to the functions of important organs (liver, kidney, heart). In addition, IND combined with CIP induced macrophages to significantly change their expression levels of several cytokines, including interleukin (IL) -1β, IL-6, IL-10, IL-22, IL-23A, IL-17A, IL-17F, cluster of differentiation (CD) 11b and other genes/encode proteins. Further study showed that intervention with the PI3K inhibitor LY294002 modulated the secretion function of the above-mentioned macrophages and Akt activation (phosphorylation at serine 473). IND plus CIP can regulate macrophage function through the PI3K/Akt signalling pathway and improve the prognosis of severe traumatic infected mice. This may be a new therapeutic strategy for the prevention and treatment of severe traumatic infection.

The combination of ciprofloxacin and indomethacin suppresses the level of inflammatory cytokines secreted by macrophages in vitro

PURPOSE

The combined use of antibiotics and anti-inflammatory medicine to manage bacterial endotoxin-induced inflammation following injuries or diseases is increasing. The cytokine level produced by macrophages plays an important role in this treatment course. Ciprofloxacin and indomethacin, two typical representatives of antibiotics and anti-inflammatory medicine, are cost-effective and has been reported to show satisfactory effect. The current study aims to investigate the effect of ciprofloxacin along with indomethacin on the secretion of inflammatory cytokines by macrophages in vitro.

METHODS

Primary murine peritoneal macrophages and RAW 264.7 cells were administrated with lipopolysaccharide (LPS) for 24 h. The related optimal dose and time point of ciprofloxacin or indomethacin in response to macrophage inflammatory response inflammation were determined via macrophage secretion induced by LPS. Then, the effects of ciprofloxacin and indomethacin on the secretory functions and viability of various macrophages were determined by enzyme-linked immunosorbent assay and flow cytometry analysis, especially for the levels of interleukin (IL)-1β, IL-6, IL-10, and tumor necrosis factor (TNF)-α. The optimal dose and time course of ciprofloxacin affecting macrophage inflammatory response were determined by testing the maximum inhibitory effect of the drugs on pro-inflammatory factors at each concentration or time point.

RESULTS

According to the levels of cytokines secreted by various macrophages (1.2 × 10⁶ cells/well) after administration of 1 μg/mL LPS, the optimal dose and usage timing for ciprofloxacin alone were 80 μg/mL and 24 h, respectively, and the optimal dose for indomethacin alone was 10 μg/mL. Compared with the LPS-stimulated group, the combination of ciprofloxacin and indomethacin reduced the levels of IL-1β (p < 0.05), IL-6 (p < 0.05), IL-10 (p < 0.01)), and TNF-α (p < 0.01). Furthermore, there was greater stability in the reduction of inflammatory factor levels in the combination group compared with those in which only ciprofloxacin or indomethacin was used.

CONCLUSION

The combination of ciprofloxacin and indomethacin suppressed the levels of inflammatory cytokines secreted by macrophages in vitro. This study illustrates the regulatory mechanism of drug combinations on innate immune cells that cause inflammatory reactions. In addition, it provides a new potential antibacterial and anti-inflammatory treatment pattern to prevent and cure various complications in the future.

The effect of rutin on pulmonary contusion induced by blunt trauma in rats: Biochemical and histopathological evaluation

BACKGROUND

This study aims to investigate the possible protective effects of rutin, also called vitamin P1, against pulmonary contusion induced by blunt chest trauma in a rat model.

METHODS

Thirty male albino Wistar rats were separated into three equal groups as healthy group, trauma group, and trauma+rutin group. After anesthesia provided by intraperitoneal administration of 60 mg/kg ketamine and xylazine by inhalation at appropriate intervals, 200 g weight was dropped from 1 m height to the anterior chest wall of the animals in the trauma group (n=10) and trauma+rutin group (n=10) and pulmonary contusion was created. Thirty min after the trauma, 50 mg/kg of rutin was administered into the stomach of trauma+rutin group animals orally with gavage. The rats received rutin once daily for two days and were sacrificed 48 h later. Their lung tissues were removed and examined biochemically and histopathologically.

RESULTS

Nuclear factor-kappa B, cyclooxygenase-2, and malondialdehyde levels increased in the trauma group compared to the healthy group, and rutin administration prevented this increase. Total glutathione levels decreased in the trauma group, and rutin administration also prevented this decrease. The histopathological findings were compatible with the biochemical findings.

CONCLUSION

Our study results suggest that rutin has a protective effect on contused lung tissue in rats.

Optimization and Application of an Efficient and Stable Inhalation Exposure System for Rodents

Inhalation is a promising and challenging method in pharmaceutical and biological science research. A stable environment is critical in dynamic inhalation administration. However, the establishment of a stable inhalation system is very challenging. Indacaterol glycopyrronium bromide inhalation powder (IM/GP mixed powder) is composed of indacaterol maleate and glycopyrronium bromide powder to treat chronic obstructive pulmonary disease (COPD). The aim of this study is to build suitable inhalation conditions and then to evaluate the pulmonary safety of this drug in Sprague-Dawley(SD) rats. In the research, through the coordination of the atomization flow, air pump flow, and scraper speed, aerosols were stabilized at 200 ± 20% mg/m³, and then rats were nose-only administered with the IM/GP mixed powder, Ultibro, and lactose-magnesium stearate mixed powder at 2.6 mg/kg/day for 14 days and 14 days of recovery period, respectively. After exposure, hematology, inflammatory cytokines in rats bronchoalveolar lavage fluid (BALF) and serum, histopathological examination were performed. Results showed that the stability of powder aerosols can be realized under the atomization generation flow: 10 L/min, sampling flow: 2 L/min, system pumping capacity: 10 L/min and powder scraper speed: 8-10 L/min, and there were no significant adverse effects on body weight, clinic signs, hematology, and pathology in rats. Overall, the results suggested that the IM/GP mixed powder inhalation at the dose of 2.6 mg/kg/d can be reached when the aerosol concentration is within the range of 200 ± 20% mg/m³, and there were no pulmonary toxicity effects in rats.

Dexmedetomidine alleviates blunt chest trauma and hemorrhagic shock‑resuscitation‑induced acute lung injury through inhibiting the NLRP3 inflammasome

Blunt chest trauma with hemorrhagic shock frequently induces pulmonary inflammation that leads to acute lung injury (ALI). The present study aimed to explore the protective effects of dexmedetomidine (Dex) in blunt chest trauma and hemorrhagic shock-resuscitation (THSR)-induced ALI by mediating nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome formation in rats. An ALI model in rats induced by THSR was constructed and Dex was administered intraperitoneally (5 µg/kg/h) immediately after blunt chest trauma. Blood samples were collected for the determination of proinflammatory factor levels, and lung tissue specimens were harvested for wet/dry (W/D) weight ratio, hematoxylin and eosin staining, and transmission electron microscopy analyses. Additionally, malondialdehyde (MDA), superoxide dismutase (SOD), lactate dehydrogenase (LDH) and myeloperoxidase (MPO) activity were evaluated, and the expression of protein in lung tissues was examined via western blot analysis. Compared with the sham group, pathological alterations in the ALI group and the W/D ratios were significantly increased. MDA, LDH and MPO activity, and the levels of interleukin (IL)-1β, IL-18, IL-6 and tumor necrosis factor-α were significantly elevated. NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain and caspase-1 expression was significantly increased. Conversely, Dex treatment significantly reversed these changes. The present study demonstrated that by reducing inflammatory responses, Dex exerted protective effects against THSR-ALI in rats, potentially via the inhibition of NLRP3 signaling pathways.