Natural products with therapeutic properties are important sources of new biologically active compounds and have been used in many parts of the world for decades, attracting  the  interest   of   many   researchers   (Araújo, 2011). Numerous studies show that some natural products are the main source of chemical diversity while new discoveries in the pharmaceutical field are emerging (Mishra and Tiwari, 2011). The plant selection to pharmacological study is a very important step. The choice can be done by one of several ways, such as the traditional, by the chemical components, random selection or combination of more than one criterion (Albuquerque and Hanazaki, 2006). The evaluation of isolated substances, fractions or extracts obtained from the vegetable drug can occur through the characterization of their biological activity, research of the mechanisms assigned to constituents and parts of the plant, determination of their active concentration and their toxic potential (Toledo et al., 2003).

RESULTS AND DISCUSSION

In the analysis of the works that make up this review has been shown that, in several studies, the authors employ various scientific names to designate the E. bulbous species (Mill.) Urb., mainly Eleutherine american (Aubl.) Merr. ex K.Heyne and Eleutherine plicata Herb. ex Klatt. The first is considered in Plant List (2015) of the Royal Botanical Garden (Kew) and the second is cited as a synonym in the two bases of the main botanical institutes (Plant List, 2015; Tropic, 2015). Thus, to keep the nomenclatures adopted by the authors in this study we chose to use the scientific names originally employed in the work referred in this review, presented in the sections and tables that make up this study. Thus, the initial citation of the accepted nomenclature was standardized, that is, bulbous Eleutherine, and in the sequence jobs with the two most commonly used synonyms.

 

Taxonomic

E. bulbous has the following taxonomic according to Angiosperm Phylogeny Group III system (2009) (Tropics, 2015).

Kingdom: Plantae

Class: Equisetopsida

Subclass: Magnoliidae

Suborder: lilianae

Order: Asparagales

Family: Iridaceae

Genus: Eleutherine

Species: Eleutherine bulbous

 

Scientific and vernacular synonyms

E. bulbous (Mill.) Urb has as botanical synonyms: Bermudiana bulbous (Mill.) Molina; Bermudiana congesta (Klatt) Kuntze; Cipura plicata (Sw.) Griseb.; Eleutherine american (Aubl.) Merr. ex K. Heyne; Eleutherine anomala Herb.; Eleutherine longifolia Gagnep.; Eleutherine plicata (Sw.) Herb.; Eleutherine plicata Herb. ex Klatt; Eleutherine subaphylla Gagnep.; Ferraria parviflora Salisb.; Galatea american (Aubl.) Kuntze; Galatea bulbous (Mill.) Britton; Galatea plicata (Sw.) Baker; Ixia american Aubl.; Sisyrinchium altissimum Ten.; Sisyrinchium americanum (Aubl.) Lemée; Sisyrinchium bulbosum Mill.; Sisyrinchium capitatum Pers.; Sisyrinchium congestum Klatt; Sisyrinchium elatum Seub. ex Klatt; Sisyrinchium intihuatanense (Vargas) Ravenna; Sisyrinchium latifolium Sw.; Sisyrinchium palmifolium var. Intihuatanense Vargas; Sisyrinchium plicatum (Sw.) Spreng.; Sisyrinchium racemosum Pers. (Kew, 2015).

E. bulbous is the currently accepted scientific name for this species, according to databases of Kew (Plant List, 2015) and the Missouri Botanic Garden (Tropicos, 2015). The vernacular names are marupari, marupazinho (Schultes and Raffaulf, 1990; Project..., 2015), marupapiranga (Schultes and Raffaulf, 1990), coquinho, lily-leaf-of-palm, marupá, marupaí, marupá-piranga, Palmeirinha (Project ..., 2015) and Rhubarb-of-field (Brasileiro et al.; 2006). In other countries it is known as Jasin huaste, pacahuasten, Pacha huaste, pachahuasten, piri-piri, yagua Piripiri, Yahuar piri piri and WA-ro (Project ..., 2015).

For synonym Eleutherine plicata, have been assigned the following vernacular names: marupazinho (Baraúna and Rock, 2006; Oliveira Neto et al., 2007; Lorenzi and Matos, 2008; Menezes et al., 2009; Nascimento et al., 2012), coquinho (Sousa et al., 2005; Oliveira Neto et al., 2007), marupari (Oliveira Neto et al., 2007; Nascimento et al., 2012), marupá-piranga, Palmeirinha, Marupa-ú and nambu marrow (Oliveira Neto et al., 2007).

 

Geographical distribution

The E. bulbous species is native of Americas, frequent in this area (Saralamp et al., 1996; Afanas'ev et al., 1999; Johnson, 1999; Lorenzi and Matos, 2002; Paramapojn et al., 2008; Nascimento et al., 2012). In Brazil, it occurs in the Amazon region, mainly in the state of Roraima (Revilla, 2001; 2002a).

For the E. american synonym, the studies indicate your origin in the tropical America, being found in plantations around the world mainly in South Africa, China, Indonesia and Thailandia (Chen et al., 1986; Hara et al., 1997).

Already by the synonymy E. plicata several studies indicate this species as widely found in the Amazon region (Baraúna and Rock, 2006; Oliveira Neto et al., 2007; Lorenzi and Matos, 2008).

 

Morphological description

The species of Eleutherine genus are herbaceous, perennial, rhizomatous and bulbous, predominantly red bulbs or wine color with scales similar to the onion, medium with 20 to 30 cm (Revilla, 2001; Lorenzi and Matos, 2002; Revilla, 2002b; Baraúna and Rocha, 2006).

Goldblatt and Le Thomas (1992) showed that the Eleutherine genus has monossulcado pollen grain with heterogeneous exine in different parts of the grain, almost perforated proximal surfaces.

Jobs reported that E. bulbous presents features simple leaves, whole, along pleated, with 25 cm average length; the flowers are white or pink, arranged in a large panicle at the apex of a long hard scape above the foliage, with 5 to 6 petals soldered on the base (Revilla, 2001, 2002b; Lorenzi and Matos, 2002).

Studies developed by Lorenzi and Matos (2002) and Baraúna and Rocha (2006) with E. plicata also identified the presence of whole leaves, pleated, simple, verticillate, linear-lanceolate, with longitudinal ribs; the inflorescence is in panicles of white flowers or roses, at the height of an escapement.

Kuntorini and Nugroho (2010) described the changes of the anatomical characteristics that occur in the leaves and the bulb of the E. american species during the plant growth cycle, showing that the specie leaf has homogenous mesophyll suffering change in thickness during growth of the plant. Prismatic crystals of calcium oxalate were observed in the mesophyll of this leaf. There is the presence of stomata on both sides of the leaf epidermis, with difference in number according to the development stage, however, on the average, the lower surface has a higher concentration of these. The thickness of the lower and upper epidermis layers also varied in the growth stage of the plant, and in general, the upper epidermis consists of smaller cells than the cells of the upper face. On the bulb, an increse in diameter and length with the growth of the plant was demonstrated. Anatomically, the bulb has difference in the size and number of parenchymal cells in which was observed the presence of calcium oxalate crystals of different shapes, with predominance of styloid. In the bulb was also verified increase in the vascular bundles structures.

These authors also evaluated the concentration of naphthoquinones during the growth sategs of the plant. In the bulb, there was an increase in the amount of this active ingredient, with the growth of the parenchyma; however the leaves, the concentration of naphtho-quinones remained constant evaluated in phases, despite the increase in thickness of the mesophyll (Kuntorini and Nugroho, 2010).

 

Use of the specie

Some studies have shown the predominance of the popular employment of leaves and E. bulbous bulbs for medical purposes, for gastrointestinal disorders (Table 1); being also employee as contraceptives, equimóticos healing by healers of Peru and abortive by the population of Haiti (Project ..., 2015; Weninger et al., 1982) and in indigenous communities of Guyana (Lorenzi and Matos, 2002) and Brazil (Ribeiro, 2008). Kainer and Duryea (1992) refer to representation of E. bulbous in extractive activities of women reservation communities in the state of Acre, Northern Brazil.

 

 

 

Study developed by Nascimento et al. (2012) refers potential E. plicata as therapeutic option in primary health care in the Amazon region.

Employment in Asian cuisine (Zhengxiong et al., 1984), in the treatment of cellulite (Revilla,  2002b)  and  as  an ornamental (Revilla, 2001) represent the only indications of non-medicinal popular use for the species of the genus Eleutherine.

 

Chemical constituents

In chemical studies of E. bulbous predominates analysis with bulbs, indicating the presence of secondary metabolites, proving the presence of naphthoquinones and anthraquinones, especially the eleuterina (Table 2). Chemical constituents of the aerial parts were studied by Paramapojna et al. (2008); and the underground parts were identified metabolites in study of Xijing et al. (2009).

 

 

 

 

 

 

Phytochemical screening revealed the presence of alkaloids, steroids free, hydroxybenzoic, quinones, anthraquinones, fixed coumarins, flavonoids and chalcones auronas in E. bulbous (Delgado et al., 1997). Studies held with E. american bulbs indicated the presence of anthraquinones (Komura et al., 1983).

Phytochemical screening with hydroalcoholic extracts  of  E. plicata  indicated  the  presence  of alkaloids, catechins, flavanones and coumarins in leaves and stem; Fixed acids, flavanonois, steroids and condensed tannins in the leaves and triterpenoid (Sousa et al., 2005). The presence of alkaloids was confirmed by Baraúna and Rocha (2006). Phenolic compounds, coumarin derivatives, and Depsides depsidonas, reducing sugars and organic acids were cited by Baraúna and Rocha (2006).

 

Pharmacological studies

Naphthoquinones (eleuterinona) isolated of dichloromethane extract E. bulbous bulbs demon-strated strong activity against the fungus Cladosporium sphaerospermum (Xu et al, 2006).

Antimicrobial properties and coronary dilating action, potentially useful in treating heart disease have been attributed to species rhizomes extract (Lorenzi and Matos, 2002). Zhengxiong et al. (1984) indicate that eleuterol and eleuterina isoeleuterina isolated of rhizomes extracts of the specie have antifungal activity and enhances the flow of the bloodstream, including coronary artery.

Eleuterina, isoeleuterina, elecanacina and isolated isoeleuterol bulbs of bulbous Eleutherine showed inhibitory activity against HIV replication (Hara et al., 1997).

Voravuthikunchai et al. (2007) showed anti-bacterial activity of E. bulbous on Streptococcus pyogenes. Ifesan and Voravuthikunchai (2009) demonstrate that the extract ethanolic species bulbs can be used as an additive in the pork meat; indicating mild anti-bacterial effect and significant antioxidant activity.

In vitro assays performed with Eleutherine leaf extracts bulbous giardicidal showing activity against Giardia lamblia (Amaral, 2007) and amebicide against Entamoeba histolytica / Entamoeba dispar (Nascimento et al., 2012) represent the only biological studies to validate the ethno-pharmacological use.

Oliveira Neto et al. (2007) in biomonitored study indicate a steroidal sapogenin with peripheral analgesic properties and anti-dematogênica, as active ingredient in E. plicata bulbs extract.

E. plicata crude lyophilized extract has shown anti-edema and peripheral analgesic activity, but not   central   (Baraúna   and   Rock,   2006);   and moderate anti-fungal activity (Menezes et al., 2009). Study of hydroalcoholic extract of your bulbs has shown anticholinesterase action (Cavalcante et al., 2009).