Hyssop is a plant of the Lamiaceae family useful against coughs, colds and asthma. The flowering tops contain flavonoids, tannins, bitter substances (marrubin) and a very pleasant essential oil, responsible for most of its balsamic and expectorants.
Sources:
A review on Hyssopus officinalis L.: composition and biological activities Fatemeh Fathiazad and Sanaz Hamedeyazdan. African Journal of Pharmacy and Pharmacology Vol. 5(17), pp. 1959-1966, 8 November, 2011
Marrubium is a perennial plant that belongs to the family of Labiateae. It contains many substances including essential oils, diterpenes, tannins, and flavonoids that characterize its use as an antispasmodic, anti-inflammatory, and analgesic. In fact, marrubium acts by inhibiting the action of many neurotransmitters, such as acetylcholine, bradykinin, prostaglandin E2, histamine, and oxytocin. In traditional medicine, it has always been used as an expectorant, diuretic, and carminative, due to a bitter substance, marrubin, which acts at the level of the respiratory and gastrointestinal systems.
Sources:
Assessment report on Marrubium vulgare herba. EMA/HMPC/604273/2012
Eucalyptus is a plant of the Myrtaceae family. The essential oil is obtained from the distillation of the leaves, which have multiple therapeutic properties. It is used as a decongestant, as it reduces inflammation and soothes irritation of the nasal mucosa, thins mucus on which it has an expectorant action and facilitates the expulsion of phlegm. In aromatherapy, it is used for inhalations in cases of cold, sinusitis, rhinitis, and cough. It also has an effective antibacterial activity against both gram-positive and gram-negative bacteria, antiviral activity against herpes virus, and antifungal properties.
Sources:
Assessment report on Eucalyptus globulus L. aetheroleum/HMPC/307782/2012
Polygala is a herbaceous plant that belongs to the Polygalaceae family. It is known for its properties as a laxative, expectorant, emollient and stomachic. These important therapeutic activities are due to the presence of polygalin, saponins, tannins, mucilage and heteroside gualterine. Administered in therapeutic doses, it is commonly used as an expectorant, therefore excellent in cases of cough, whooping cough, colds, asthma, bronchitis, respiratory diseases. Polygala also stimulates diuresis and sweating, and this helps in case of fever. Polygala also has a laxative action and is therefore useful in the presence of intestinal problems, helping thus the elimination of waste harmful to the organism.
Fonti:
LODI V., Fitoterapia, 16, 41, 1940