## 1 Introduction  
The members of the genus _Pulmonaria_ commonly known as lungwort belong to the family Boragniaceae. It comprises around 18 species of perennial flowering plants that are widely dispersed across Europe, Russia, and Western Asia [1]. Lungwort (especially _Pulmonaria officinalis_) has been used for medicinal purposes since ancient times due to the Doctrine of Signatures as it resembles diseased lungs [2]. Lungwort has been known for its use for pulmonary diseases in folk medicine without the knowledge of its precise mechanisms of action. The ethnochemical use of lungwort includes emollient, antitussive, expectorant, antimicrobial, diuretic, depurative, antilithiatic, and anti-inflammatory usage, as well as in respiratory and urinary disorders [3, 4].  
The leaves and flowers from _Pulmonaria_ are known to have been used as a wild plant food in the past [5, 6]. _Pulmonaria_ flowers can be considered as feeding stations for insects and _P. officinalis_ is also included in most common honey plants in Estonia [7]. The flowers are shaped like cylindrical tubes, which have five-lobed corolla at the ends. The size of the flower is around 0.5-1.5 cm in diameter, and in its center is the style, which can be short (thrum) or long (pin). Both pin and thrum flowers are present on the same plant in the _Pulmonaria_ species [8]. Generally, most of the _Pulmonaria_ plants are spring-flowering woodlanders and prefer humus-rich, moist soil to grow (they do not favor dry or waterlogged soil).  
Several commercial products from lungwort (_P. officinalis_) are available on the market, such as mother tincture, leaves, dried aerial parts (commercially available as _Pulmonaria_ herba), ingredients of various dietary supplements, as tea, and as cosmetics [9]. Different forms/parts of lungworts such as the extract from the aerial parts, leaves, roots, callus culture, isolated compounds, and nanoparticles have been used to explore/study their biological properties in in vitro and/or in vivo experiments. Several potential biological properties such as antioxidant, anti-inflammation, antianemic, anticoagulant, wound healing, anti-neurodegenerative, anticonvulsant and skin whitening activities have been studied for lungwort [10; 11; 12; 13; 14]. These biological activities have the potential to be developed for medicinal and/or food supplement usage in different diseases or conditions. _P. officinalis_ is also listed in the national health product databases of different countries for possible pharmaceutical use, such as the National Database of Health Protection Products of Poland and the Natural Health Products Ingredients Database of Canada ([[http://webprod.hc-sc.gc.ca/nhpid-bdipsn/atRed.do?atid=lungwort.oral&lang=eng](http://webprod.hc-sc.gc.ca/nhpid-bdipsn/atRed.do?atid=lungwort.oral&lang=eng)]([http://webprod.hc-sc.gc.ca/nhpid-bdipsn/atRed.do?atid=lungwort.oral&lang=eng](http://webprod.hc-sc.gc.ca/nhpid-bdipsn/atRed.do?atid=lungwort.oral&lang=eng)); accessed on 30 March 2022). The biological properties of lungworts may be attributed to the diverse set of phytochemicals, such as anthocyanins, alkaloids, flavanone, flavonoids, flavones, hydroxycinnamic acid, lignans, polyphenols, polyphenic acids, and other phytochemicals present in different parts of the plants. In the literature, more than a hundred phytochemicals have been reported from lungwort.  
Limited studies have been carried out on lungworts for their medicinal properties to be developed as approved therapeutic approaches or supplements for diseases or conditions. However, a comprehensive compilation of the biological properties and phytochemicals present in lungworts is not available, which could provide the gaps, highlight the challenges, and suggest possible solutions for the further development of lungwort as a food supplement and/or therapeutic candidate for pharmacological applications.