Introduction

Ethnobotany studies the relationship between human groups with the plant environment, as well as the use that human beings give to this renewable resource. Medicinal plants are species that produce chemical compounds that have shown effectiveness in the treatment of conditions and that over the years, have been of great help to humans throughout the world (^{Pardo & Gómez, 2003}).

Ethnobotanical studies on medicinal plants in Ecuador, mainly in the central Andean and in the Amazon regions, focus on the knowledge that the inhabitants of these areas possess on their benefits (^{Cerón, 2003}). The importance of medicinal plants is based on the health care of human beings, especially for communities in developing countries who do not have access to modern medicine (^{Vera & Sánchez, 2015}).

Ethnobotanical studies on medicinal plants carried out in the coastal region of Ecuador are scarce; besides, most of these have been developed in indigenous communities (^{Zambrano, Buenaño, Mancera, & Jiménez, 2015}). Therefore, it is of great interest to conduct ethnobotanical research in coastal peasant communities, where people also have a constant relationship with their plant environment and with plants.

According to ^{Rocha (2011)}, for this field of knowledge, there is a great interest in Ecuador, where a diversity of 500 species is estimated, of which 228 have been recorded more frequently; of these, 125 are destined for commercialization, and are marketed as fresh and dried product, and as powder extracts or as essential oils. The main destination of these, are buyers in the United States, Germany, France, Italy, and The Netherlands.

Accordingly, the aim of this work was to establish the ethnobotanical use and commercialization of the medicinal plants of the Murocomba Protective Forest in the Valencia canton, Ecuador, and its area of influence, to obtain timely information on the matter, with a focus on the conservation and sustainability of these resources.

Materials and methods

Fieldwork

The study was carried out between August 2017 and January 2018, through field visits. To define the number of surveys that should be carried out, the total population that lives in the six locations of the Murocomba protective forest and its area of influence was considered, with a total of 56 households (100 % of the population). A structured survey was designed, with closed questions, addressed to one of the persons in the household who knows and provides information on plant species for medicinal use. The most significant number of surveys was carried out in the locality of Isla de la Libertad with 26 households or sampling units, compared to the locality of Gonzales Suárez, where only one household was surveyed.

Source: Elaborated by the authors

Figure 1. Location of the Murocomba protective forest and its area of influence in the province of Los Ríos.a. Location of the province of Los Ríos in the Ecuadorian territory; b. Location of the Valencia canton in theprovince of Los Ríos; c. Location of the study area. 

The purpose of the surveys was to obtain information on the socio-cultural aspects of the interviewees, such as his/her name, age, gender, and name of the locality to which he/she belongs. Additionally, also data referring to medicinal plants, such as the disease that it heals, employment form, preparation, way of administration and part(s) of the plant used in the treatment of diseases.

A total of 56 informants were interviewed, including 28 women and 28 men, whose age range was between 20 and 100 years; hence, informants were classified into four intervals as follows. Interval I, between 20 and 40 years; interval II, between 41 and 60 years; interval III, between 61 and 80 years; IV interval, between 81 and 100 years.

Statistical analysis of ethnobotanical data

The data obtained were processed with the use of the Microsoft Excel 2010 software and the IBM SPSS program, through descriptive statistics and frequency analysis. The software PAST 2.02 (^{Hammer, Harper, & Ryan, 2001}) was employed to calculate the Simpson and Shannon diversity index and the Jaccard similarity index. For the calculation of the interaction between the six locations in the forest, the cluster analysis method was used, which allows grouping the six locations with higher species similarity. To establish significant differences between the locations of the Murocomba protective forest and its area of influence, the analysis of variance (Anova) was used based on the number of individuals per species in the six locations studied, using the PAST 2.02 software (^{Hammer et al., 2001}).

The t statistic was used to assess significant differences in the six locations of the Murocomba protective forest, depending on the parameters species, individuals, dominance, Shannon, Simpson, and similarity. The use value index ( uvi ), the relative knowledge index (rki), and the Significant Use Tramil ( sut ) were calculated to establish the cultural importance of the species.

Use Value Index (UVI)

The uvi established the most important species or with cultural value for all informants interviewed in each sampling unit. Equation 1, according to ^{Phillips (1996)}, was used to calculate the general UVI of each species for all informants (UVIs).

Where UVis is the use-value of the species per informant, and Ns is the number of informants per species.

Relative knowledge index (RKI)

To calculate the RKI, equation 2, proposed by ^{Phillips (1996)}, was used.

Where VUis is the use-value of the species per informant; UVIs is the use-value index of the species, and Nsp is the number of informants per species.

Significant use Tramil (SUT)

The level of significant use for each species and its cultural acceptance was established using the methodology proposed by ^{Germosén (1995)}, which states that the medicinal uses by each informant, cited with a frequency higher than or equal to 20 %, can be considered significant due to their cultural acceptance, and deserves to be evaluated and validated scientifically. The SUT was calculated using equation 3 (^{Germosén, 1995}).

Where Use species is the number of citations for each species, and Nis is the number of informants surveyed.

Results and discussion

A total of 51 medicinal plants species distributed in 44 genera and 26 botanical families were found. These results are similar to another ethnobotanical study conducted in the San Carlos parish, Quevedo canton by ^{Zambrano et al. (2015)}, and in the San Jacinto community, Ventanas canton by ^{Paredes, Buenaño and Mancera (2015)}, with 29 and 21 families, respectively. The families with the highest number of medicinal plant species in the study area were Lamiaceae (8 species), Asteraceae (6 species), Euphorbiaceae and Rutaceae (3 species each) (figure 2), which coincides with a study conducted in rural areas of the Bogotá Plateau in Colombia by ^{Pérez and Matiz (2017)}, where the Lamiaceae family showed a higher number of species (14 species - 6 %). In Ecuador, Asteraceae, Fabaceae, and Rubiaceae are the families with the highest number of species with medicinal uses (^{Balslev, Navarrete, Torre, & Macías, 2008}), a result similar to the one found in a study carried out by ^{Bernal, García and Quevedo (2011)} in Colombia.

The species most frequently found in the study site, in descending order, were Cymbopogon citratus (DC.) Stapf. (Poaceae) with 25 citations; Ocimum americanum L. (Lamiaceae) with 23; Calendula officinalis L. (Asteraceae) with 19; Plectranthus amboinicus (Lour.) Spreng. (Lamiaceae) with 18; Hyptis actinocephala Griseb. (Lamiaceae) with 18; Ruta graveolens L. (Rutaceae) with 15; Aloe vera (L.) Burm.f. (Asphodelaceae) with 15; Melissa officinalis L. (Lamiaceae) with 13, and Scoparia dulcis L. (Plantaginaceae) with 14. On the other hand, the following species were recorded with a minimum frequency: Bryophyllum adelae (Hamet) A.Berger (Crassulaceae), Artocarpus altilis (Parkinson ex F.A.Zorn) Fosberg, (Moraceae), Cestrum nocturnum L. (Solanaceae), Columnea orientandina (Wiehler) L.P.Kvist & L.E.Skog (Gesneriaceae), Croton lechleri Müll.Arg. (Euphorbiaceae), Euphorbia cotinifolia L. (Euphorbiaceae), Iresine lindenii Van Houtte (Amaranthaceae), Jatropha curcas L. (Euphorbiaceae), Petiveria alliacea L. (Petiveriaceae), Phyllanthus acidus (L.) Skeels (Phyllanthaceae), Portulaca oleracea L. (Portulacaceae), Portulaca sp. (Portulacaceae), Psychotria viridis Ruiz & Pav. (Rubiaceae), and Tanacetum parthenium (L.) Sch.Bip. (Asteraceae). The species with the highest absolute frequency in the current research was C. citratus. Similar results were obtained in the research conducted by ^{Zambrano et al. (2015)}, in which the same species showed the highest frequency in the sites sampled.

Source: Elaborated by the authors

Figure 2. Frequency of species per botanical family found in the Murocomba protective forest and its area ofinfluence, Ecuador, in 2018. 

The location Isla de la Libertad showed a higher number of species with medicinal use (44 species), as well as the highest number of individuals, with 149 records. The most dominant locality within the study area was Gonzales Suárez with 0.5 (table 1).

The Shannon index for the Murocomba protective forest and its area of influence showed medium diversity; the locality Isla de la Libertad showed the highest diversity with 3.42. These results are different from those obtained by ^{Vásquez (2014)} in a study carried out in the urban gardens of canton Loja, in which the Shannon index indicates a high diversity in the parish of El Valle (3.9). Regarding the Simpson index, the site with the highest diversity was Isla de la Libertad with 0.9569, in contrast to the study carried out by ^{Vásquez (2014)}, who concluded that the four parishes studied have high diversity with values higher than 0.9. Regarding the similarity index, the site with a value equal to 1 is Gonzales Suárez.

The Jaccard index calculated for the six locations of the study area shows the interaction of El Dorado and Murocomba with 0.57143 × 100 % as the one with the highest similarity of species (table 2).

Table 1. Species, individuals, dominance and diversity indices of the medicinal plants found in the Murocomba protective forest and its area of influence, Valencia canton, Ecuador 

Source: Elaborated by the authors

Table 2. Jaccard index interactions matrix between localities in the area of influence of the Murocomba protective forest 

Source: Elaborated by the authors

The results of the cluster analysis used in the Dorado, Río Negro, and El Mirador de Valencia; localities of the study area show two clusters the second group is formed solely by Gonzales above 12.90 %. The first group is formed by Suárez as it is distant from the first group the localities Isla de la Libertad, Murocomba, El (figure 3).

Source: Elaborated by the authors

Figure 3. Similarity dendrogram of the sampling units of the Murocomba protective forest, Valencia canton, Ecuador. 

The Anova exposes significant differences in the forest, being p = 1.126E-19 < 0.05 at 95 % of studied locations of the Murocomba protective probability (table 3).

Table 3. Analysis of variance for the establishment of frequency in the localities of the Murocomba protective forest, Valencia canton, Ecuador 

Source: Elaborated by the authors

The Tukey’s means separation test (table 4) shows significant differences between the locations of El Dorado and Gonzales Suárez (p = 3,23E-05).

The Student’s t-test for separation of means (table 5) in the six locations of the Murocomba protective forest and considering the indexes evaluated, exposes significant differences p < 0.05 for species(p = 0.0268), for individuals (p = 0.0882), for the Shannon index (p = 0.0021), for the Simpson index (p = 0.0001), and for the similarity index(p = 0.0000).

Table 4. Tukey’s means separation test for peer comparisons between localities of the Murocomba protective forestand its area of influence, Valencia canton, Ecuador 

Source: Elaborated by the authors

Table 5. Student's t-test for separation of means at p < 0.05 probability for the six locations of the Murocombaprotective forest 

Source: Elaborated by the authors

The subcategories of medicinal use most frequently found are digestive system diseases and infectious and parasitic diseases (32.5 %). In general, infections (18.9 %) are the most treated illnesses in the research conducted by ^{Gallegos (2017)}, unlike the current research in which medicinal plants are used to treat most diseases that affect the entire body and others (32.9 %) as well as gastrointestinal problems (31.9 %) (figure 4).

Source: Elaborated by the authors

Figure 4. Subcategories of medicinal use best represented in the traditional medicine of the communities located inthe Murocomba protective forest and its area of influence. 

In the research carried out by ^{Fernández, Minaya and Palomino (2015)}, 46 % of the persons prefer to boil the medicinal plants they will use, 34 % consume them raw, 15 % leave them to rest for a while, and only 5 % use them in infusion; similar results were obtained in the current research where most of the treatments were prepared by cooking (66.78 %) and by grounding (27.9) (figure 5).

Source: Elaborated by the authors

Figure 5.  Method used to prepare treatments with medicinal plants in the study area. 

The most commonly used administration route for the consumption of medicinal plants was by drinking (61.7 %) as well as by external use (33.9) as can be seen in Figure 6. These results are similar to those presented by ^{Domínguez, Cruz and González (2015)}, where 67.5 % of the plants are prepared as drinks and ingested in this way.

The leaves are the part of the plant that is mostly used in the preparation of medicinal treatments and represent 84.9 % of the total structures used for this purpose (figure 7). Similar results were obtained in the research by ^{Domínguez et al. (2015)}, which indicates that the leaf is used more frequently in the preparation of medicinal treatments (54.1 %), followed by the root (10.2 %); this contrasts with the research carried out by ^{Fernández, Minaya and Palomino (2015)}, in which 61 % of the respondents prefer to use the fruits and only 23 % use the leaves.

Source: Elaborated by the authors

Figure 6.  Administration route of medicinal treatments in the study area. 

Source: Elaborated by the authors

Figure 7.  Part of the plant used in the preparation of medicinal treatments in the area of influence of the Murocombaprotective forest. 

Species with the highest SUT reported in the Murocomba protective forest and its area of influence

Table 6 shows the plant species for medicinal usewith a SUT value higher than 20 %; among thesewe find C. citratus (44,64), O. americanum (41,07),C. officinalis (33,93), P. amboinicus (32,14), H.actinocephala (32,14), S. dulcis (28,57), R. graveolens(26,79) and A. vera (26,79).

Table 6. Use value indices of species used for medicinal purposes in the Murocomba protective forest and its area of influenceAbbreviations: use-value index (UVI), relative knowledge index (RKI), and significant use Tramil (SUT). 

Source: Elaborated by the authors

Analysis of the propagation knowledge of medicinal plants with higher SUT in the Murocomba protective forest and its area of influence

Eight medicinal plants with the highest sut were identified. Of these species used for medicinal purposes, respondents propagated them employing two or three methods. A comparison was made between the propagation methods used by the inhabitants registered in the cited literature (table 7), and the ones reported in the study area with the highest sut. Seeds, cuttings, and plant division are the most frequently used propagation methods by the population surveyed in the Murocomba protective forest and its area of influence. These results are similar to those found by ^{Paván, Furlan, Caminos and Ojeda (2016)} in San Pedro, northern Argentina, where the authors carried out 30 interviews to the residents on the recognition, use and production of medicinal plants, who said they propagate these from seeds and cuttings.

Table 7. Comparison matrix of surveys applied to the inhabitants of the study area, with literature cited on the propagation methods of medicinal plants identified with the highest SUT 

Source: Elaborated by the authors

Conclusions

In the six locations of the Murocomba protective forest and its area of influence, 51 medicinal plant species were obtained and grouped into 44 genera and 26 botanical families. The Asteraceae, Lamiaceae and Plantaginaceae families and the species Cymbopogon citratus, Ocimum americanum and Calendula officinalis showed the highest frequency.

The Shannon and Simpson indices express a varied diversity of medicinal plants in the study area localities, being low, medium and high according to the locality; hence, Isla de la Libertad was the one that showed the highest diversity. The localities El Dorado and Isla de la Libertad showed the highest similarity of medicinal plants. The locations analyzed in the current research showed significant differences in frequencies of medicinal plant species according to the Anova at 95 % probability. The Student’s t-test exposes significant differences for species, individuals, and the indices of Shannon, Simpson, and similarity (Jaccard) between the six sampling locations.

For the elaboration of the medicinal treatments, the leaves are mostly used, and the preparation method preferred is by cooking or infusion. Therefore, the route of administration of the medicine is oral or by drinking, and these are used to treat diseases that affect the entire body, known scientifically as culturebound syndromes (i.e., evil eye, bad air, among others), followed by those that affect the gastrointestinal system.

According to the use value index, the relative knowledge of the species by several informants and the level of significant use Tramil, the species with the highest cultural value are Cymbopogon citratus, Ocimum americanum and Calendula officinalis.

Surveys show that the inhabitants of the Murocomba protective forest and its area of influence mainly use the asexual propagation method using cuttings to propagate existing medicinal plants in the study area; meanwhile, the reproduction and multiplication of the species reported with the highest SUT is carried out using seeds, cuttings or through plant division. Of the eight species reported with the highest sut, the only one that correlates in the study area is Ruta graveolens, which means that the other species identified can be incorporated into the market.

Disclaimers

All the authors made significant contributions to this document, and agree with its publication. Moreover, they state that there are no conflicts of interest in this study.