Ca’ Granda, Hortus simplicium: Restoring an Ancient Medicinal Garden of XV–XIX Century in Milan (Italy)

This work is based on the study of 150 majolica vases dated back to the mid XVII century that once preserved medicinal remedies prepared in the ancient Pharmacy annexed to the Ospedale Maggiore Ca’ Granda in Milan (Lombardy, Italy). The Hortus simplicium was created in 1641 as a source of plant-based ingredients for those remedies. The main objective of the present work is to lay the knowledge base for the restoration of the ancient Garden for educational and informative purposes. Therefore, the following complementary phases were carried out: (i) the analysis of the inscriptions on the jars, along with the survey on historical medical texts, allowing for the positive identification of the plant ingredients of the remedies and their ancient use as medicines; (ii) the bibliographic research in modern pharmacological literature in order to validate or refute the historical uses; (iii) the realization of the checklist of plants potentially present in cultivation at the ancient Garden, concurrently with the comparison with the results of a previous in situ archaeobotanical study concerning pollen grains. For the species selection, considerations were made also regarding drug amounts in the remedies and pedoclimatic conditions of the study area. Out of the 150 vases, 108 contained plant-based remedies, corresponding to 148 taxa. The remedies mainly treated gastrointestinal and respiratory disorders. At least one of the medicinal uses was validated in scientific literature for 112 out of the 148 examined species. Finally, a checklist of 40 taxa, presumably hosted in the Hortus simplicium, was assembled.


Introduction
Ospedale Maggiore Ca' Granda (Milan, Lombardy, Italy), today known simply as Policlinico, is considered one of the oldest hospitals in all of Italy. Founded in 1456 at the behest of Francesco Sforza, Duke of Milan, and based on a design by the architect Antonio Averlino, its main purpose was to provide free medical care to the poorest inhabitants of the city as well as improve the efficiency of the healthcare system across the diocese territory. For centuries, this institution was considered a model in the construction of many other European hospitals [1]. The building included also a Pharmacy, place of research, preparation, and distribution of different remedies, as testified by a historical document from 1470 [2][3][4][5]. Between 1640 and 1643, the Hospital commissioned ceramist Michele Valli, from Lodi, to manufacture 575 majolica pots for the ingredients of the annexed Pharmacy, while new supplies of vases were secured over the course of the first half of the XVIII century [6]. At the dawn of World War II, 196 pots were still viable. However, after the bombings, only 150 remained unscathed to this day. Of these, 37 were part of the original production, while the remaining ones were realised during the 1700s. The aforementioned collection is currently preserved by the Service for Cultural Assets of the Policlinico [7]. The vases were used to preserve both single ingredients and complex remedies. These specimens were often plant-based and were processed in the Pharmacy to be administered to the patients of the Hospital. In 1641, a Garden of Simples, annexed to the Hospital, was built. Gardens of Simples, also known as Horti simplicium, are considered to be precursors of the modern Botanic Gardens. Originally, back in the Middle Ages, Gardens of Simples were structures connected to ancient monasteries for the cultivation and study of medicinal plants. Later on, they became more prominent in universities, where the plants were used primarily for educational purposes. In contrast, the Garden of the Ospedale Maggiore Ca' Granda of Milan was annexed to a hospital and the plants therein ended up being directly part of the remedies concocted for the patients [4]. With the emergence of pharmaceutical chemistry in the first half of the XIX century, the ancient Garden gradually lost its relevance as a source of medicinal plants and began to be used as an ornamental green area, no longer intended for the cultivation of medicinal species. During the 1930s, the layout of the Garden was modified due to renovation works of the main building. In the 1960s, additional construction works determined a gradual reduction of the Garden surface area. Today, the area where the ancient Garden stands covers only 680 m 2 , 520 of which are simple lawns [4].
The work presented herein aims at laying the scientific knowledge basis for the future restoration of the ancient Garden of Simples, in the framework of the historical value and educational enhancement of a little-known cultural heritage in Milan. A multidisciplinary approach of investigation was adopted, beginning from the study of the actually preserved 150 majolica jars. The work included complementary subsequent phases: (1) historical survey, with the purpose of defining the composition of the remedies contained in the jars and their historical medical use, focusing on plant-based ingredients; (2) pharmacological research, performed through the consultation of the current relevant scientific literature, in order to either validate or refute the ancient medicinal uses of the plants surveyed; (3) compilation of a checklist of taxa that were potentially present in cultivation in the ancient Garden of Simples.

Inscriptions Analysis and Interpretation
The 150 jars were categorised into three types ( Figure 1): spool albarelli (albarelli a rocchetto, or slender terracotta containers with a short neck and a large opening) of two different sizes ( Figure 1a); jugs (orcioli, or pot-bellied containers with a hole at the bottom that allows easy spilling of the contents, Figure 1b); and spheroidal bottles (Figure 1c). The pots are made of white majolica with bear blue decorations and the inscriptions are in old Gothic style and black ink. Each vase is numbered progressively. The inscriptions are written in Latin or vulgar Italian and are for the most part abbreviated, thus making information concerning the ingredients and the types of preparation sometimes hard to discern. In some cases, the abbreviations were hard to interpret also due to potential spelling mistakes made by the decorator, or to the presence of uncommon and unfamiliar words. As a way of example, we cite vase n. 33, Syrupus d. Duab. Rad., which was the extremely contracted version of the Latin Syrupus de Duabus Radicibus. For these reasons, the inscriptions needed attentive reading. Based on the interpretation of the labels and the origin of the main ingredients, the jars were further categorised as plant-based (108 vases; vase n. 17, which contained as the main ingredient mushrooms belonging to the genus Agaricus, was also included in this category), animal-based (13), mineral-based (8), or unknown origin (21; in these cases, both the deciphering of the inscriptions and the historical survey yielded no usable results). Finally, the plant-based category was subdivided into 15 groups, based on the type of preparation: aqua (27 vases; aqueous extract); syrupus (21; syrup); trochiscus (18; dosage form similar to granules); oleum (12; oleolytes); unguentum (9; ointment); electuarium (6; electuary); pilulae (5; dosage form similar to tablets); mel. ros (2; honey-based composition); pulvis (2; powder); reb/roab (2; condensed syrup); oxymel (2; liquid preparation based on honey and vinegar); diatrum (1; preparation made up of three components); emplastrum (1; poultice); floris (1; flowers); opiatus poter. (1; opium-based preparation). It is worth recalling that the remaining jars represent only a limited part of all the products that could originally be found in the Pharmacy, thus giving us only partial knowledge concerning the remedies used. See Table 1 for details.  In some cases, the abbreviations were hard to interpret also due to potential spelling mistakes made by the decorator, or to the presence of uncommon and unfamiliar words. As a way of example, we cite vase n. 33, Syrupus d. Duab. Rad., which was the extremely contracted version of the Latin Syrupus de Duabus Radicibus. For these reasons, the inscriptions needed attentive reading. Based on the interpretation of the labels and the origin of the main ingredients, the jars were further categorised as plant-based (108 vases; vase n. 17, which contained as the main ingredient mushrooms belonging to the genus Agaricus, was also included in this category), animal-based (13), mineral-based (8), or unknown origin (21; in these cases, both the deciphering of the inscriptions and the historical survey yielded no usable results). Finally, the plant-based category was subdivided into 15 groups, based on the type of preparation: aqua (27 vases; aqueous extract); syrupus (21; syrup); trochiscus (18; dosage form similar to granules); oleum (12; oleolytes); unguentum (9; ointment); electuarium (6; electuary); pilulae (5; dosage form similar to tablets); mel. ros (2; honey-based composition); pulvis (2; powder); reb/roab (2; condensed syrup); oxymel (2; liquid preparation based on honey and vinegar); diatrum (1; preparation made up of three components); emplastrum (1; poultice); floris (1; flowers); opiatus poter. (1; opium-based preparation). It is worth recalling that the remaining jars represent only a limited part of all the products that could originally be found in the Pharmacy, thus giving us only partial knowledge concerning the remedies used. See Table 1 for details. Acorus calamus L., Artemisia absinthium L., Ceterach officinarum Willd., Cinnamomum verum J.

Plant Species in the Remedies and Validation of the Historical Medicinal Use
A total 108 plant-based remedies were cross-referenced on a wide type of historical sources, such as ancient pharmacopoeias, medical texts, and almanacs published between the XV and the XIX century . In this manner, a total of 148 plant taxa, belonging to 58 different botanical families, were found. The complete list is available in Table S1. The most cited families were Apiaceae and Lamiaceae (16 taxa; 10.8%), Compositae (12; 8.1%), Rosaceae (9; 6.1%), and Leguminosae (7; 4.7%), while the most represented genera were Mentha, Origanum, and Prunus (3 species each) followed by Commiphora (2), Ferula (2), and Pistacia (2).
The survey of the modern pharmacological literature highlighted that at least one historical therapeutic effect was validated for 112 taxa out of 148. On the contrary, it is noteworthy that the effects reported in literature for Matricaria chamomilla L. were opposite in comparison with the uses documented by the historical sources; specifically, in the past it was used in a laxative remedy [20], while the modern literature referred to antidiarrheal properties [79]. Of the consulted literature contributions, 17 reported different plant parts when compared with the ones used in the past. For example, historical sources cited roots and seeds to be used for Asarum europaeum L. [9,13,19], while the current pharmacological studies were focused on the plant aerial parts [80]. Table 2. Categories of the pathologies treated with the 108 plant-based remedies, according to historical sources published between the XV and the XIX century . The total number of vase-remedies used for the treatment of each category, along with the total number of plant-based ingredients in the remedies, are reported.

Plant Species Checklist for the Restoration of the Ancient Garden of Simples
The historical and pharmacological bibliographic research based on the inscriptions of the jars allowed listing of the 148 plant taxa that were actively employed at the Ospedale Maggiore Ca' Granda in Milan. If the ancient Pharmacy was indeed the place of manufacture and distribution of the medicinal remedies, it is well-documented that since 1641, the Garden of Simples was the place of cultivation of the plants that made up the remedies themselves [4]. However, to this day, there is very little information concerning the pool of plants hosted in the Garden. The results of the archaeological and palynological analysis performed by Bosi et al. [4] on both plant remains and pollen grains recovered in the area of study, represent a first attempt to resolve this pivotal issue. As a matter of fact, concerning the herbaceous plants, the authors recovered pollen grains belonging to several species of the Apiaceae (probably including Carum carvi L., Pastinaca sativa L., Anethum graveolens L., Aethusa cynapium L., and Pimpinella anisum L. Still) and Compositae families (with Calendula officinalis L., Centaurea benedicta (L.) L., and maybe Centaurea jacea L.). Additionally, further taxa belonging to different families were identified, such as species of the genera Hypericum, Euphorbia, Mercurialis, Mentha, Allium, and Reseda. The remaining pollen residues turned out to be more difficult to interpret, because it could belong to species hosted in the Garden, to plants cultivated nearby, or even weeds. These included Papaver spp., Potentilla spp., Artemisia spp., and Brassica spp. The woody species, on the other hand, presented a more difficult challenge. According to Bosi's team [4], these plants could have been cultivated both for medicinal purposes and as ornamentals. Among these, the following species were identified: evergreen species belonging to the genera Buxus and Juniperus, and fruit-bearing trees such as Morus nigra L., Cydonia oblonga Mill., Juglans regia L., Prunus spp. (perhaps P. avium L.), and Vitis spp. (most likely V. vinifera L.). Additional species that were present at the time were Humulus lupulus L., Fraxinus ornus L., Cornus mas L., Olea europaea L., and Castanea sativa L. Nevertheless, according to the authors, it is unreasonable to completely exclude the possibility that these plant remains did not come to be at the Garden from neighbouring areas of Lombardy's territory.
It should also be considered that of the 148 taxa, 76% are autochthonous, growing spontaneously across Italy. However, Milan's pedoclimatic conditions of the time must also be taken into account. Some species could not have been cultivated in the Garden back in the XVII century due to their thermal requirements, regardless of their presence in the rest of the country. Among these were Cinnamomum camphora (L.) J. Presl, Cinnamomum verum J. Presl, Convolvulus scammonia L., Curcuma longa L., Myristica fragrans Houtt., and Pistacia terebinthus L. On the other hand, other species could have been cultivated in the Garden by taking special precautions, most likely protecting them from cold weather. Examples of these plants are Capparis spinosa L., Drimia maritima (L.) Stern, Glycyrrhiza glabra L., and Myrtus communis L. Conversely, plant species such as Citrus limon L. or Citrus medica L., which prefer more temperate climates, could have been hosted in a sunny and sheltered spot. Another important factor to be considered is the limited area dedicated to cultivation (about 680 m 2 ). It is, in fact, improbable that there were a great number of arboreal species, as well as Loranthus europaeus Jacq., which grows as an epiphyte on trees.
An additional consideration arises on the plant part and the drug amounts used in the remedies production. Hypogeal organs were historically requested for some of the woody species, such as Capparis spinosa L. and Glycyrrhiza glabra L. Thus, it is reasonable to assume it very unlikely that even a portion of the already limited growing area was dedicated to plants that would have been completely eradicated to obtain the drug. However, these species could be considered excellent additions for the future restored Garden, for display and educational purposes. Some species were seldomly employed in remedies and/or in very limited amounts (i.e., Sanguisorba officinalis L. and Pulmonaria spp.). Others, instead, were used in a variety of recipes (i.e., Artemisia absinthium L. and Ruta graveolens L.). Therefore, it is possible to deduce that the formers were actually grown in the Garden, whereas the latter were most likely supplied from elsewhere. Some historical documents preserved in the Hospital archive were consulted as well (ingredients indexes and supply lists from 1711, 1729, 1760, and 1793 and pharmacopoeias from 1809, 1810-1820, 1819, and 1839 [285][286][287][288][289][290][291][292][293]). Out of the 148 in our complete list, 85 species were cited in the aforementioned documents, 36 of which were in at least 5 of them. It can be thus hypothesised an actual and continuative use of these plants inside the Hospital during the XVIII and XIX centuries. However, some of the supply lists confirm that several of these species and their derivatives were purchased from outside the Pharmacy; these included Acacia senegal (L.  [288]. Other species, cited in at least 5 of the documents but absent from the supply list, could have been hosted in the Garden; among these are Juniperus communis L., Laurus nobilis L., and Matricaria chamomilla L. Finally, plant-based ingredients such as wine and olive oil were used as a base for most of the remedies produced at the Pharmacy. For this reason, it is more than likely that they too were purchased goods, as opposed to being obtained from the cultivation of Vitis vinifera L. and Olea europaea L. in the Garden. Both these plants would also benefit a potential restored Garden, both as ornamentals and examples of their ancient use. Taking into account all the aforementioned considerations, a list of 40 taxa, belonging to 20 botanical families, was compiled. The most represented families are Lamiaceae (12 species) followed by Compositae and Apiaceae (4 species each), while the most represented genera are Origanum (3) and Mentha (2). The information obtained, along with the 40 species list, represent the basis for the future project of restoration of the ancient Hortus simplicium. The complete list is reported in Table 3. Table 3. List of species selected for the restoration project of the ancient Hortus simplicium.
Where possible, consultation of writs in vulgar Italian was preferred. The inscriptions were matched directly with the names of the remedies found in the different historical sources. Subsequently, the jars were catalogued according to the origin of either the remedy or the main ingredient. The categories utilised were "plant-based", "mineral", and "animal". All the plant-based ingredients were then tabulated along with the following information: current scientific name (consulting the specialised website http://www. theplantlist.org/, accessed on 30 September 2021), weight, historical medicinal use, and historical source.

Pharmacological Research
Extensive bibliographic research in the pharmacological field was carried out on the plant species obtained during the historical survey phase in order to either validate or refute their ancient medicinal uses. To that end, it was necessary to interpret the historical medical terminology of the pathologies in a modern setting. During this research, several databases were consulted, such as PubMed, Scopus, Google Scholar, and the bibliographic research online tool known as J.A.N.E. A two-step approach was used during the inquiry. Firstly, either the scientific or the common English name of the species was matched with specific keywords related to the categories of pathology that were obtained from historical sources (i.e., Acorus calamus, 'digestive system' or 'gastrointestinal disorders'). Secondly, the plant name was matched with the specific pathology or activity (i.e., Acorus calamus, 'laxative' or 'anti-inflammatory'). The research was primarily focused on systematic reviews and meta-analysis, whenever possible, without applying any year filters. Alternatively, in vitro and in vivo studies, as well as clinical trials, were consulted. The literature inquiry was extended to the mechanism of action, when known. All data were tabulated along with the following information: family, species (scientific and common name), inscription on the vase and inventory number, part of the plant historically used, historical sources, modern use obtained from the historical medicinal use, mechanism of action, and bibliographic references (for complete data, please see Table S1 [ [294][295][296][297]).

Checklist of Potentially Cultivated Species at the Ancient Garden of Simples
The list of the plant species obtained from the historical research was compared with data from the archaeobotanical study by Bosi et al. [4]. This study was performed on pollen grains recovered at the area of the ancient Garden. This process allowed for the identification of the plant taxa that were potentially present in cultivation at the study area. Each species in the list was then evaluated according to the relative cultivation requirements and the pedoclimatic conditions of the area at the time. Finally, additional considerations were made concerning the part of the plant used in the remedies, the amount in use at the ancient Pharmacy, and XVIII century archived supply ledgers.

Conclusions
Until the end of the XIX century, official medicine was inextricably linked to the use of plant-based complex remedies. Scientific texts and pharmacopoeias of the time describe elaborate recipes in which animal and mineral ingredients were mixed with plant derivatives in order to produce concoctions that had reportedly almost magical properties. In a time when synthetic drug production was in its infancy and antibiotics did not even exist, in hospitals, doctors administered these peculiar preparations as valid therapies. Ospedale Maggiore Ca' Granda in Milan, along with the annexed Pharmacy and ancient Garden of Simples, was for centuries the main venue for these ancient therapeutic practices that could be considered both fascinating and debatable. The multidisciplinary approach of research described herein allowed for the coalescence of results obtained from several complementary fields of study, such as history, pharmacology, archaeology, and agronomy, with the common goal of investigating the plant species used in therapy during the XV-XIX centuries. This was made possible thanks to the accurate analysis of the 150 surviving majolica vases actually preserved in the Pharmacy and once used for the conservation of the ingredients and complex remedies administered to the patients of the Hospital. Through this survey, we could speculate on the pool of species that were once hosted in the ancient Garden of Simples. Finally, the information gleamed in this study will prove to be instrumental in the future restoration project of the Hortus simplicium, in the framework of the historical value and the educational enhancement of a little-known cultural heritage in Milan.
Supplementary Materials: The following are available online. Table S1: Results of the pharmacological survey in scientific literature.