Medicinal plants – prophylactic and therapeutic options for gastrointestinal and respiratory diseases in calves and piglets? A systematic review

Ayrle, Hannah; Mevissen, Meike; Kaske, Martin; Nathues, Heiko; Gruetzner, Niels; Melzig, Matthias; Walkenhorst, Michael

In human medicine, Thymus vulgaris L. has been already effectively used according to its antitussive and mucolytic effects in the treatment of acute bronchitis, often in combinations with other plant species, e. g. Primula veris L. for its expectorant effects [108] [109] [110] . The main active compound of Thymus vulgaris L. is the essential oil containing thymol, geraniol, thujanol and linalool [111] . The above mentioned effects still have to be investigated for veterinary purposes. Nevertheless, an enhancement of the mucociliary clearance in mice was shown in two in vivo studies [112, 113] . This effect was explained by an interaction with beta 2 receptors in rat lung tissue [112] . Additionally, three ex vivo studies demonstrated spasmolytic effects of Thymus vulgaris L. on tracheal chains comparable to theophylline [114] [115] [116] . The reported antiinflammatory properties [117] and antibacterial effects found in in vitro studies [118] [119] [120] of Thymus vulgaris L. still needs to be investigated in clinical studies. In vivo studies on the toxicology of Thymus vulgaris L. leaf extract showed no toxic potential [121, 122] . In summary, the data available support the potential for using Thymus vulgaris L. for treatment of respiratory diseases in livestock.