DOI: 10.5433/1679-0367.2013v34n2p111 Pimenta pseudocaryophyllus (Gomes) L.R. Landrum (Myrtaceae): stem and leaf anatomy of a medicinal plant Pimenta pseudocaryophyllus (Gomes) L.R. Landrum (Myrtaceae): anatomia do caule e da folha de uma planta medicinal Dayana Lacerda Custódio1; Rosana Marta Kolb2; Terezinha de Jesus Faria3; Edmilson Bianchini4 Abstract The study of medicinal plants involves several areas of science. Anatomy contributes to species identification and consequently, with quality control of plant product. This paper describes the leaf and stem anatomy of Pimenta pseudocaryophyllus (Gomes) L.R. Landrum (Myrtaceae), collected in Seasonal Semideciduous Forest. The studied organs presented uniseriate epidermis covered by a thick cuticle and secretory cavities. The stem showed a continuous ring of vascular tissues around the pith, with phloem on both sides of the xylem. The leaf was hypostomatic, with trichomes on the abaxial face, with bifacial mesophyll and amphicrival vascular bundle, surrounded by a sclerenchymatous pericycle in the petiole and in the midrib. Among the histochemical tests, positive results were obtained for lipids, phenolic compounds, starch and calcium oxalate (druses). The species had anatomical features typical of the family and the secretory cavities present in leaves and stems were related to the secondary metabolites detected. Keywords: Secondary metabolites. Secretion. Secretory cavities. Tropical tree. Resumo O estudo de plantas medicinais envolve várias áreas da ciência. Neste contexto, a anatomia contribui para a identificação da espécie e consequentemente, com a qualidade do produto da planta. Este trabalho descreve a anatomia do caule e da folha de Pimenta pseudocaryophyllus (Gomes) L.R. Landrum (Myrtaceae), coletada em Floresta Estacional Semidecidual. Os órgãos estudados apresentaram epiderme unisseriada, recoberta com cutícula espessa, e cavidades secretoras. O caule apresentou anel contínuo de tecido vascular ao redor da medula, com o floema em ambos os lados do xilema. A folha foi hipoestomática com tricomas na face abaxial, com mesofilo bifacial e feixe vascular anficrival circundado por periciclo esclerenquimático no pecíolo e na nervura principal. Entre os testes histoquímicos, resultados positivos foram obtidos para lipídeos, compostos fenólicos, amido e oxalato de cálcio (drusas). A espécie apresentou aspectos anatômicos típicos da família e as cavidades secretoras presentes nas folhas foram relacionadas aos compostos secundários detectados. Palavras-chave: Cavidades secretoras. Compostos secundários. Espécies tropicais. Secreção. 1Departamento de Biologia Animal e Vegetal, Centro de Ciências Biológicas, Universidade Estadual de Londrina. E-mail: [email protected] 2Departamento de Biologia, Universidade Estadual Paulista Júlio de Mesquita Filho, Campus Assis. E-mail: rosanakolb@hotmail. com 3 Departamento de Química, Centro de Ciências Exatas, Universidade Estadual de Londrina. E-mail: [email protected] 4 Departamento de Biologia Animal e Vegetal, Centro de Ciências Biológicas, Universidade Estadual de Londrina. E-mail: [email protected] 111 Semina: Ciências Biológicas e da Saúde, Londrina, v. 34, n. 2, p. 111-124, jul./dez. 2013 Custódio, D. L. et al. Introduction phenolic compounds (DUARTE; DEBUR, 2005). In an anatomical and chemical study of Rustia The anatomical study of medicinal plants formosa (Rubiaceae), Vieira et al. (2001) observed contributes to the correct species identification secretory cavities with lipids between the palisade and consequently, with quality control of plant and the spongy parenchyma in foliar lamina and in product. The diagnosis of plants is made initially the cortical region of the petiole. by morphological analysis of their vegetative and reproductive organs and their organoleptic According to Metcalfe; Chalk (1979), secretory characteristics. However, the knowledge of their cavities are common in Myrtaceae species. Some of micro-morphology is very important for the them are used as medicinal plants by the population. establishment of patterns, in order to compare For example, in Psidium widgrenianum, which has samples of plant specimens used as drugs, proving anti-inflammatory and antineoplasic activities, their authenticity. Make use of plants, erroneously Donato; Morretes (2005) found secretory cavities identified, is a risky attitude and may lead to the with essential oils distributed in both faces of its failure of the expected pharmacological effects or leaves and calcium oxalate druses near the vascular to undesirable reactions due to the presence of toxic bundles. Donato; Morretes (2007) evaluated the leaf substances in plants (DONATO; MORRETES, anatomy of specimens of Eugenia brasiliensis, from 2005, 2007). two localities, and found numerous secretory cavities with essential oils in both faces of the leaf; the Among the anatomical characters, secretory number of observed cavities was different between structures and secreted material are very interesting the localities studied. In Eugenia dysenterica, used to anatomists and taxonomists, because they often to combat diarrhea, Palhares (2003) found a large give a distinctive appearance to cellular patterns in number of glands scattered in the mesophyll. The the plants where they are present (METCALFE; author also noted the occurrence of druses and CHALK, 1989). This affirmation is corroborated idioblasts containing rhomb crystals of calcium by many studies in the literature. For example, oxalate. Ciccarelli, Andreucci and Pagni (2001) studying Hypericum perforatum (Hypericaceae), a species Pimenta pseudocaryophyllus (Gomes) L. R. traditionally used as tranquilizer, antidepressant Landrum (Myrtaceae), known as “craveiro”, has and anti-inflammatory, found translucent glands its leaves used by population for production of on leaves, sepals and petals; and three different tea for flu and in the culinary, besides of its use as types of canals, considering the whole body of this wood (LORENZI, 2002). It is a Brazilian endemic plant. Sant’Anna-Santos et al. (2006) evaluated the species found mainly in the Cerrado and Atlantic anatomy and histochemistry of secretory structures Forest (LANDRUM; KAWASAKI, 1997). In of the stem of Spondias dulcis (Anacardiaceae) pharmacognostic studies of P. pseudocaryophyllus, and found tanniniferous idioblasts and canals Paula et al. (2006) and Paula et al. (2008) collected with a complex secretion composed by essential stems and leaves, respectively, from individuals oils, polysaccharides and phenolic compounds. growing in Cerrado biome, and detected the presence Silva; Machado (1999) studied the structure and of phenolic compounds, tannins and flavonoids. the development of secretory trichomes on leaves Antimicrobial (PAULA, 2006) and antifungal (EL of Piper regnellii var. regnellii (Piperaceae). They ASSAL, 2012) activity has been suggested to the found two kinds of secretory trichomes: pearl extract of this species. Because of its importance, glands and sac-like trichomes. In stem and leaves of it is essential to provide detailed information about Maytenus ilicifolia (Celastraceae), used for gastritis the anatomy and the histochemistry of stems and and ulcers, were found prismatic crystals and leaves of P. pseudocaryophyllus. The leaf anatomy 112 Semina: Ciências Biológicas e da Saúde, Londrina, v. 34, n. 2, p. 111-124, jul./dez. 2013 Pimenta pseudocaryophyllus (Gomes) L.R. Landrum (Myrtaceae): stem and leaf anatomy of a medicinal plant was described by Paula et al. (2008) and Farias et al. covered with hairs. The fruits are subglobose, 0.8- (2009) from material collected in Cerrado and Mixed 1.5 cm long and the seeds are hard, shiny, sometimes Ombrophilous Forest, respectively. Considering angular, 0.4-0.8 cm long (LANDRUM, 1986). that environmental conditions can affect the leaf Samples of P. pseudocaryophyllus were collected anatomy, it is necessary to evaluate plants in in a semi-deciduous seasonal forest fragment other vegetation formations where the species (23°43’30” S e 50°43’47” W), localized in São occurs naturally, as the Seasonal Semideciduous Jerônimo da Serra, Paraná State, Brazil. The climate Forest. These studies may contribute to the correct is Köppen’s Cfa with a mean annual rainfall between identification of the species and to obtain parameters 1400 to 1600 mm and mean annual temperature for quality control of plant material. between 18 to 20ºC. In the summer rains from 500 In this context, this study aims to describe the to 600 mm and the average temperature is between leaf and stem anatomy of P. pseudocaryophyllus, 25 to 27°C, whereas in the winter precipitation is collected in Seasonal Semideciduous Forest lower (225 to 250 mm) and temperature is between fragment, comparing our results with others 13 to 16ºC. The region has acid and low fertility described in the literature, both, for this species soils (SÁ, 2004). and others from the same family. These organs The voucher was deposited in the Herbarium of were studied because they are the only ones used in Universidade Estadual de Londrina (FUEL 43025). popular medicine and more used in phytochemical Samples were collected from 10 randomly chosen studies. The results will allow to evaluate if the individuals in the edge of the remnant. For each of species presents anatomical plasticity and to them, we sampled five leaves (all from second node) establish a description pattern for the correct and two terminal segments of stems. Fragments of identification of the species. these organs