H2S donating corticosteroids: Design, synthesis and biological evaluation in a murine model of asthma

Introduction

Hydrogen sulfide (H2S) is a fundamental biological endogenous gas-mediator in the respiratory system. It regulates pivotal patho-physiological processes such as oxidative stress, pulmonary circulation, airway tone and inflammation.

Objectives

We herein describe the design and synthesis of molecular hybrids obtained by the condensation of several corticosteroids with different hydrogen sulfide releasing moieties.

Methods

All the molecules are characterized for their ability to release H2S both via amperometric approach and using a fluorescent probe. The chemical stability of the newly synthesized hybrid molecules has been investigated at differing pH values and in human serum.

Results

Prednisone-TBZ hybrid (compound 7) was selected for further evaluations. The obtained results from the in vitro and in vivo studies clearly show evidence in favor of the anti-inflammatory properties of the released H2S.

Conclusions

The protective effect on airway remodeling makes the hybrid Prednisone-TBZ (compound 7) as a promising therapeutic option in reducing allergic asthma symptoms and exacerbations.

Neutrophil migration during liver cirrhosis in rabbits

1. The aim of the present study was to investigate neutrophil chemotaxis during the induction of liver cirrhosis in rabbits. 2. Liver cirrhosis was induced in male New Zealand white rabbits. The study consisted of three experimental groups: (i) group A (n=16) served as the control and received only normal chow and all rabbits in this group were killed at 16 weeks; (ii) group B rabbits (n=8) were killed immediately after the chemotaxis assay, which was performed 24 h after CCl4 administration, at weeks 2, 4, 6 and 8; and (iii) in group C rabbits (n=19), the chemotaxis assay was performed every second week on the day before CCl4 administration for 16 weeks and all animals in this group were killed at 16 weeks. 3. Four of six rabbits in group B had liver cirrhosis at week 8. In group C, liver cirrhosis occurred in seven of eight animals. All rabbits with liver cirrhosis had an inflammatory infiltrate of neutrophils. In group B, there was a significant increase in polymorphonuclear cells and neutrophil chemotaxis and a significant reduction in mononuclear leucocytes at week 8. The rabbits in group C showed a significant increase in total leucocyte and polymorphonuclear numbers at week 10. A significant increase in neutrophil chemotaxis was also observed from week 2 through to week 6. 4. The presence of neutrophils in the liver of all rabbits with cirrhosis, associated with an increase in polymorphonuclear cell chemotaxis during this process, supports the view that this cell type has an important role in the development of toxic liver damage.