Inhibition of the healing of gastric ulcer by glucocorticoid and its relation to proinflammatory cytokines

Duloxetine protected indomethacin-induced gastric mucosal injury by increasing serotonin-dependent RANTES expression and activating PI3K-AKT-VEGF pathway

Antidepressant duloxetine has been shown protective effect on indomethacin-induced gastric ulcer, which was escorted by inflammation in the gastric mucosa. Cytokines are the principal mediators of inflammation. Thus, by screening the differential expression of cytokines in the gastric mucosa using cytokine array at 3 h after indomethacin exposure, when the gastric ulcer began to format, we found that indomethacin increased cytokines which promoted inflammation responses, whereas duloxetine decreased pro-inflammatory cytokines increased by indomethacin and increased RANTES expression. RANTES was consistently increased by pretreated with both 5 mg/kg and 20 mg/kg duloxetine at 3 h and 6 h after indomethacin exposure in male rats. Selective blockade of RANTES-CCR5 axis by a functional antagonist Met-RANTES or a CCR5 antagonist maraviroc suppressed the protection of duloxetine. Considering the pharmacologic action of duloxetine on reuptake of monoamine neurotransmitters, we examined the serotonin (5-HT), norepinephrine and dopamine contents in the blood and discovered 20 mg/kg duloxetine increased 5-HT levels in platelet-poor plasma, while treatment with 5-HT promoted expression of RANTES in the gastric mucosa and alleviated the indomethacin-induced gastric injury. Furthermore, duloxetine activated PI3K-AKT-VEGF signaling pathway, which was regulated by RANTES-CCR5, and selective inhibitor of VEGF receptor axitinib blocked the prophylactic effect of duloxetine. Furthermore, duloxetine also protected gastric mucosa from indomethacin in female rats, and RANTES was increased by duloxetine after 6 h after indomethacin exposure too. Together, our results identified the role of cytokines, particularly RANTES, and the underlying mechanisms in gastroprotective effect of duloxetine against indomethacin, which advanced our understanding in inflammatory modulation by monoamine-based antidepressants.

Pandemic aspect of dexamethasone: Molecular mechanisms and clinical application

The rapid spread of coronavirus disease (COVID-19) in many countries has caused inconvenience in conducting daily life activities, and even deaths. Dexamethasone is a corticosteroid applied in clinical medicine since 1957, especially in immune therapy fields. Herein, we present the characteristics of Dexamethasone, from molecular mechanisms such as genomic and nongenomic pathways by cellular signal regulations, to clinical applications in various phases of the disease. During COVID-19 pandemic, Dexamethasone given to patients who required oxygen or ventilation therapy showed improved life efficacy.

Drug interactions in the treatment of rheumatoid arthritis and psoriatic arthritis

BACKGROUND

Treating patients with inflammatory joint diseases (rheumatoid arthritis, psoriatic arthritis) according to established treatment algorithms often requires the simultaneous use of three or more medications to relieve symptoms and prevent long-term joint damage as well as disability.

OBJECTIVE

To assess and give an overview on drug-drug interactions in the pharmacotherapy of inflammatory joint diseases with regards to their clinical relevance.

METHODS

All possible drug combinations were evaluated using three commercially available drug interaction programs. In those cases where only limited/no data were found, a comprehensive hand search of Pubmed was carried out. Finally, the drug-drug interactions of all possible combinations were classified according to evidence-based medicine and a specifically generated relevance-based system.

RESULTS

All three interaction software programs showed consistent results. All detected interactions were combined in clearly structured tables.

CONCLUSION

A concise overview on drug-drug interactions is given. Especially in more sophisticated cases extensive knowledge of drug interactions supports optimisation of therapy and results in improved patient safety.

Protective effects of Ankaferd blood stopper on aspirin-induced oxidative mucosal damage in a rat model of gastric injury

The exposure of gastric mucosa to damaging factors, such as ethanol and some therapeutic drugs, produces pathological changes: inflammatory process, hemorrhagic erosions and even acute ulcers. Ankaferd blood stopper (ABS) comprises a standardized mixture of five different plant extracts. The purpose of our present investigations is to explain the participation of reactive oxygen species in acute gastric mucosal damage by acetylsalicylic acid (ASA) and the effects of new hemostatic agent ABS. Experiments were carried out on 23 male Wistar rats. To assess gastric mucosal damage, biochemical and histopathological data were used. The colorimetric assays were used to determine the malondialdehyde (MDA) and superoxide dismutase (SOD) activity. The level of myeloperoxidase (MPO) activity, the level of nitric oxide (NO) and the proinflammatory cytokine tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay technique. We demonstrated that the biological effects of ROS were estimated by measuring the tissue and plasma levels of MDA, the products of lipid peroxidation, as well as the activity of SOD and the scavenger of ROS produced by ASA in the experiment group. Moreover, it was found that MPO activity as well as NO and TNF-α levels also demonstrated significant improvement by ABS treatment. The pathogenesis of experimental ASA-induced mucosal damage in rat stomach includes the generation of ROS that seems to play an important role, due to the generation of lipid peroxides, accompanied by the impairment of antioxidative enzyme activity of cells. ABS appeared to attenuate the oxidative and inflammatory changes caused by ASA-induced gastric mucosal damage in rats.