The hydroalcoholic extract of Nasturtium officinale reduces oxidative stress markers and increases total antioxidant capacity in patients with asthma

Abstract

Ethnopharmacological relevance: Asthma is a common chronic disease characterized by inflammation of the airways. One of the most devastating consequences of this inflammatory process is the production of reactive oxygen species responsible for oxidative stress. Nasturtium officinale commonly known as watercress has traditionally been applied in Iranian folk medicine to treat respiratory disorders and diseases mainly bronchitis and asthma. In accordance with these ethnopharmacological reports, through our previous in vivo experiment, we have confirmed significant effect of its hydroalcoholic extract in reducing lung inflammation and oxidative stress in an ovalbumin-induced asthmatic rat model.

Aim of the study: The aim of the present study was to investigate the anti-inflammatory and antioxidant effects of N. officinale hydroalcoholic extract (NOE) in patients with asthma, in order to confirm our findings of the previous performed in vivo study.

Material and methods: The NOE capsules (500 mg) were treated twice daily for 4 weeks as a supplementary treatment in a randomized, double-blind, and placebo-controlled trial in asthmatics. The primary outcome was Asthma Control Test score. The blood samples were taken at the beginning and end of the study. Then, the level of inflammatory markers, oxidative stress markers and antioxidant enzyme activity were measured.

Results: Treatment with NOE for one month caused a reduction in the levels of MDA, PCO and NO metabolite markers compared to the placebo group. In addition, FRAP levels as an indicator of total antioxidant capacity in the intervention group was significantly increased at the end of the treatment period compared to pre-treatment values.

Conclusion: Findings demonstrated that NOE may have a therapeutic effect on asthma by improving oxidative stress. However, more studies are required to support these results. Moreover, bio-assay guided fractionation and isolation approach can be conducted to identify major bioactive compound/s.

Keywords: Asthma; Clinical trials; Cytokines; Malondialdehyde; Nasturtium officinale; Superoxide dismutase; Tumor Necrosis Factor α.