Sulphurous medicinal waters increase somatostatin release: It is a possible mechanism of anti-inflammatory effect of balneotherapy in psoriasis

AimBalneotherapy has been used in the treatment of immune-mediated skin diseases, but its molecular mechanism has yet to be elucidated. The aim of the present study was to observe the effect of sulphurous medicinal water in a murine dermatitis model and on psoriatic patients; moreover to investigate the role of hydrogen sulphide in the release of somatostatin during bathing treatment.Materials and methodsInflammation was induced by oxazolone in the paw skin of mice. Oedema, TNF-α concentration, histological changes and myeloperoxidase level were investigated. Mice were bathed in medicinal water or distilled water for 20 min/day. To define the effect of hydrogen sulphide on somatostatin release mice were bathed in sodium hydrosulphide solution for 2 weeks. Somatostatin plasma concentration was detected by nanoHPLC-ESI-Q-TOF-MS.In the clinical study nineteen patients (PASI: 2.2-21.6) received 2 × 25-min bath treatment for 21 days. Somatostatin-like immunoreactivity of the plasma was determined by radioimmunoassay. Before and after the balneotherapy skin biopsies were performed.ResultsOxazolone caused 29.43-33.73% paw swelling which was significantly reduced by the medicinal water. Myeloperoxidase, TNF-α levels and histological changes of the skin were unaltered. Somatostatin plasma concentration significantly increased in response to the bathing treatment.In the clinical study PASI markedly declined (0-13.4) and the plasma level of somatostatin increased significantly. Langerhans-cells migrated from the dermal pool to the epidermis.ConclusionWe conclude that balneotherapy is an effective treatment in psoriasis. Our results provided evidence that somatostatin released by H2S plays role in the mechanism of action of sulphurous medicinal water.