The impact of Sambucus nigra L. extract on inflammation, oxidative stress and tissue remodeling in a rat model of lipopolysaccharide-induced subacute rhinosinusitis.

Rhinosinusitis is a common disorder related to inflammation of paranasal sinuses and nasal cavity mucosa. Herbal medicines could be an option in the treatment of rhinosinusitis due to their anti-inflammatory and anti-oxidative properties. The study aims to investigate the effect of intranasal Sambucus nigra L. subsp. nigra (SN) extract against inflammation, oxidative stress, and tissue remodeling in nasal and sinus mucosa, but also in serum, lungs, and brain, in Wistar rat model of subacute sinonasal inflammation induced by local administration of lipopolysaccharides (LPS), from Escherichia Coli. The cytokines (TNF-α, IL-1ß, IL-6) and oxidative stress (malondialdehyde) in nasal mucosa, blood, lungs, and brain were analyzed. In addition, a histopathological examination was performed, and NF-kB, MMP2, MMP9, TIMP1 expressions were also evaluated in nasal mucosa. Both doses of LPS increased the production of cytokines in all the investigated tissues, especially in the nasal mucosa and blood (p < 0.01 and p < 0.05), and stimulated their secretion in the lungs, and partially in the brain. Malondialdehyde increased in all the investigated tissues (p < 0.01 and p < 0.05). In parallel, upregulation of NF-kB and MMP2 expressions with downregulation of TIMP1, particularly at high dose of LPS, was observed. SN extract reduced the local inflammatory response, maintained low levels of IL-6, TNF-α, and IL-1ß. In lungs, SN reduced all cytokines levels while in the brain, the protective effect was noticed only on IL-6. Additionally, SN diminished lipid peroxidation and downregulated NF-kB in animals exposed to a low dose of LPS, with increased TIMP1 expression, while in animals treated with a high dose of LPS, SN increased NF-kB, MMP2, and MMP9 levels. In conclusion, SN extract diminished the inflammatory response, reduced generation of reactive oxygen species (ROS) and, influenced MMPs expressions, suggesting the benficial effect of SN extract on tissue remodeling in subacute rhinosinusitis and on systemic inflammatory response.

A pharmacokinetic drug interaction study between nebivolol and paroxetine in healthy volunteers.

WHAT IS KNOWN AND OBJECTIVE: Nebivolol is a highly selective beta-blocker with additional vasodilator properties, widely used in the clinical practice for the treatment of hypertension and heart failure. Paroxetine is a second-generation antidepressant and a potent inhibitor of CYP2D6, the same isoenzyme involved in the metabolism of nebivolol. The objective of this study was to investigate the effect of multiple-dose paroxetine intake on the pharmacokinetics of nebivolol in healthy volunteers and its potential consequences upon nebivolol pharmacodynamics. METHODS: The study included 23 healthy subjects and was designed as an open-label, single-centre, non-randomized, two-period clinical trial. During period 1 (reference), each volunteer received a single dose of 5 mg nebivolol, whereas during period 2 (test), each volunteer received a single dose of 5 mg nebivolol and 20 mg paroxetine, after a pretreatment regimen with paroxetine (20-40 mg/day for 6 days). The pharmacokinetic parameters of nebivolol and its active metabolite were analysed by non-compartmental modelling. The pharmacodynamic parameters (blood pressure and heart rate) were assessed at rest, after each nebivolol intake. RESULTS AND DISCUSSION: Pretreatment with paroxetine increased the mean peak plasma concentrations (Cmax ) for unchanged nebivolol (1·78 ± 1·17 vs. 4·24 ± 1·67 ng/mL) and for its active metabolite (0·58 ± 0·21 vs. 0·79 ± 0·24 ng/mL) compared to nebivolol alone. The time (tmax ) to reach Cmax was 1·37 ± 0·88 (h) and 3·11 ± 1·76 (h) for the parent compound and its active metabolite after nebivolol administered alone and 3·96 ± 1·76 (h), respectively, 7·33 ± 7·84 (h) after pretreatment with paroxetine. Also, the total areas under the curve (AUC0-∞ ) were significantly increased from 17·26 ± 43·06 to 106·20 ± 65·56 h ng/mL for nebivolol unchanged and 13·03 ± 11·29 to 74·56 ± 88·77 h ng/mL for its hydroxylated metabolite, before and after paroxetine intake. All the pharmacokinetic parameters presented statistically significant differences when paroxetine was administered with nebivolol. Nonetheless, statistical analysis did not show a significant difference between the vital signs measured during the two periods. WHAT IS NEW AND CONCLUSION: After pretreatment with paroxetine, the exposure to nebivolol was increased by 6·1-fold for the parent drug and 5·7-fold for the hydroxylated active metabolite. Paroxetine influenced nebivolol pharmacokinetics in healthy volunteers, but it did not have a significant effect on nebivolol pharmacodynamic parameters measured at rest, although the clinical relevance of this drug interaction needs further investigation.