Expectorant and antioxidant activities of purified fumarprotocetraric acid from Cladonia verticillaris lichen in mice

Abstract

The lichen Cladonia verticillaris produces bioactive secondary metabolites, such as fumarprotocetraric (FUM) and protocetraric acids. Species of the genus Cladonia demonstrate anti-tumor, anti-inflammatory and antipyretic activities and have been used in folk medicine to treat respiratory diseases (throat irritation, cough, asthma and tuberculosis). The aim of the present study was to evaluate the expectorant and mucolytic activities of fumarprotocetraric acid in albino Swiss mice. FUM was extracted and purified from an acetone extract of C. verticillaris. The phenol red quantification method was used on the bronchoalveolar lavage fluid following the administration of FUM (25, 50 or 100 mg/kg orally or intraduodenally and 12.5, 25 or 50 mg/kg, intraperitoneally) for the evaluation of expectorant activity. Control groups received either saline solution (7.5 mL/kg) or ambroxol (1 mg/kg) through the same administration routes. Antioxidant activity was evaluated using the thiobarbituric acid reactive species assay in mouse lung tissue treated with the FUM at 25, 50 or 100 mg/kg orally, followed by a lipopolysaccharide solution at 1 mg/kg intrapleurally. The same protocol was used for the control groups using either saline solution (7.5 mL/kg, orally) or N-acetylcysteine (20 mg/kg, orally). Results: Orally administered FUM at doses of 25 and 50 mg/kg promoted significantly greater dose-dependent phenol red activity in the bronchoalveolar lavage and expectorant activity in comparison to the controls (p < 0.05). Lipid peroxidation (malondialdehyde equivalent) was reduced by 50% in the lung tissue. Conclusion: The results confirm the expectorant and antioxidant properties of fumarprotocetraric acid produced by the lichen C. verticillaris.