Bronchipret® film-coated tablets exert potent anti-inflammatory activity in a rat model of bronchoalveolitis

A fixed combination of thyme and primula extract (Bronchipret^® film-coated tablets [BRO]) is clinically used for the treatment of acute bronchitis. Anti-inflammatory properties are expected to substantially contribute to its efficacy in patients. We aimed to provide better understanding of the therapeutic potential of BRO on inflammatory key parameters using an in vivo model of LPS-induced bronchoalveolitis.

Bronchoalveolitis in male Wistar rats was induced by intratracheal LPS instillation (100 µg/animal). BRO was given daily at 1 – 10-fold equivalents of the human daily dose (68 – 680 mg/kg) for up to three days. Animals were sacrificed at 24h intervals up to 72h post LPS challenge to analyze cell infiltration and mediator production in bronchoalveolar lavage fluid (BALF) and myeloperoxidase activity in lung tissue.

BRO significantly reversed the LPS-induced increase of granulocyte numbers and the levels of all analyzed prostaglandins (PGD₂, PGE₂, TXA₂) in BALF at 48h post LPS instillation. It furthermore significantly normalized MPO tissue activity at 48 and 72h post LPS. All effects ranged in a similar magnitude as those of the positive control dexamethasone (5 mg/kg).

The fixed combination of thyme and primula dry extract contained in Bronchipret^® TP exerts anti-inflammatory effects in an in vivo model of bronchoalveolar inflammation. The anti-inflammatory activity of BRO should most likely contribute to its clinically proven efficacy as treatment of acute bronchitis in humans.