Folk medicine, biological activity, and chemical profiles of Brazilian Acanthaceae (Lamiales) - A review.

INTRODUCTION: The botanical family Acanthaceae (order Lamiales) potentially comprises 4900 species in 191 genera with extensive morphological, habit and habitat diversity. The family is widely distributed throughout the world but is especially rich in tropical and subtropical regions. Many of its species have great ornamental importance and are broadly used for medicinal purposes in several countries of Asia and Africa. Brazil is a main center of diversity of the family, where they are distributed across all its biomes, mainly in the herbaceous-shrub stratum. Medicinal investigations about Brazilian species are scarce, the exception being a single native species, Justicia pectoralis Jacq., that is widely used and studied chemically. AIM OF THE REVIEW: This work compiled studies that indicated folk medicinal use, investigated biological activity, or evaluated the chemical composition of Brazilian species of Acanthaceae. MATERIAL AND METHODS: Medicinal uses, investigations of biological activities and chemical data were collected and summarized through bibliographic surveys. Tables were compiled to standardize the information and the appropriate references were gathered for each species. Registration of chemical components used in the treatment of ailments and in preserving health were emphasized with the aim of stimulating future investigations. RESULTS: The breadths of habitats and morphologies of the family are directly related to its chemical diversity, as confirmed here for Brazilian species. Although the investigated species represent less than 9% of the total richness of the family in Brazil, they encompass a great diversity of chemical substances. The data indicated folk medicinal uses for 26 species and biological tests for 23, while 30 species were investigated chemically. Ruellia and Justicia were the most researched genera with 12 and 11 species, representing approximately 14% and 7% of Brazilian species of each genus, respectively. Two species are native to other countries but become naturalized in Brazil. Studies of native species were carried out in different countries around the world, with many reports of medicinal uses and biological tests. Examples of uses include anticancer and antidepressant actions, as well as activities against respiratory problems and other diseases. CONCLUSIONS: This work highlights the chemical and biological diversity of the studied Brazilian species of Acanthaceae, which emphasizes the need to expand studies with native Brazilian species.

Leaf and stem anatomical characterization of Euphorbia hirta L., a tolerant species to glyphosate.

Euphorbia hirta L. is a weed species that is tolerant to the most used herbicide in agriculture, glyphosate. The anatomical characteristics of plants influence the processes of absorption and translocation of herbicides. The objective of this work was to characterize the anatomy of the aerial vegetative axis (leaves and stem) of E. hirta, to support the establishment of strategies for better control of this species with herbicides. The plants were grown in a greenhouse under controlled conditions. When they reached sizes between 8 and 12 cm, samples of stems and leaves were collected, fixed in FAA 50, and stored in 70% ethanol. Subsequently, the samples were processed following usual light microscopy techniques. In cross-section, the stem of E. hirta has a circular shape. The leaf epidermis is uniseriate composed of isodiametric cells of compact arrangement and with the presence of multicellular trichomes and anthocyanin. As for the morphometric parameters evaluated, the young leaves have a lower thickness in the abaxial epidermis. Based on the anatomical characteristics observed in E. hirta, the main barriers that can act in the absorption of herbicides are the high hairiness and the high content of anthocyanin in the epidermal cells.

Herbivory by leaf-cutter ants changes the glandular trichomes density and the volatile components in an aromatic plant model.

Herbivory can induce several structural and functional alterations in the plant secretory system. Glandular trichomes are the main sites of production of volatile organic compounds (VOCs) with several chemical properties in Lamiaceae species. Ocimum species usually have three morphotypes of glandular trichomes (morphotype I is peltate and has a wide four-celled head; morphotype II is capitate and has a unicellular head; and morphotype III is capitate with a bicellular head) which produce a great amount of terpenes, although other chemical categories of substances are also produced. Despite the abundance of trichomes producing important anti-herbivory components in their leaves, the association between Ocimum species and leaf-cutter ants has been commonly registered in Brazil. We investigated the effect of leaf-cutter ant attack on the density of the glandular trichomes and on the chemistry of the VOCs released from leaves of O. gratissimum. Plants were subjected to Acromyrmex rugosus attack until 90 % of leaves were removed. After 40 days from the leaf-cutter attack, both treatments were sampled. The glandular trichome density was analysed by scanning electron microscopy. The VOCs were extracted utilizing headspace solid-phase microextraction (HS-SPME) technique and analysed by gas chromatography. Generally, the density of glandular trichomes increased in the adaxial leaf surface of the attacked plants. However, we bring novelties on this topic since we analysed the density of each morphotype separately. The morphotype I decreased in the abaxial leaf surface, and increased in the adaxial leaf surface; the morphotype II increased in both leaf surfaces; and the morphotype III decreased in the abaxial leaf surface and remained constant in the adaxial leaf surface of attacked plants. In leaves of attacked plants, the (Z)-ß-ocimene increased by 50 %, the α-selinene by 13 % and the germacrene D by 126 %, whereas the eugenol decreased by 70 %. Our data point to a differential response of each glandular morphotype in O. gratissimum and are consistent with the idea of a compartmentalization of functions among the different glandular morphotypes in the plant defence against environmental factors.

Fruit and seed biometry and germination of Victoria amazonica (Poepp.) J.C. Sowerby (Nymphaeaceae) from the Pantanal floodplain / Biometria do fruto e da semente e germinação de Victoria amazonica (Poepp.) J.C. Sowerby (Nymphaeaceae) do Pantanal

Numerous plant species are easily established in the wide flood plains of the Pantanal wetlands due to the environmental heterogeneity. The aquatic macrophytes excel in permanently flooded areas, particularly Nymphaeaceae species. Victoria amazonica, popularly known as the vitória-régia, is hallmarked for its beauty. However, the biology and conditions necessary for the seed germination of this flowering plant remain unknown. In the present study, the fruit and seed morphology and biometry were described and the seed germination was evaluated under different abiotic conditions. To this end, mature fruits of V. amazonica were collected from the bays near Paraguay River in the south Pantanal floodplain. The fruits and seeds were described and measured using digital caliper. Intact and mechanically scarified seeds were germinated under different temperature, light and substratum conditions, and the initial development was described. The fruits measured 67.5 x 119.7 mm in size and contained 100-700 seeds. The average seed measured 10.6 mm in length and 9.8 mm in width. The highest germination occurred at 25oC, independent of the light condition. The seeds were considered neutral photoblastic. The seedlings showed heterophylly, and the main root was degenerated, forming adventitious roots. Morphological differences were observed in seedlings developed under different light conditions.

O Pantanal, ampla planície inundável, facilita o estabelecimento de inúmeras espécies vegetais por sua heterogeneidade ambiental. As macrófitas aquáticas se destacam em áreas permanentemente alagadas, com destaque para a família Nymphaeaceae. A espécie Victoria amazonica, conhecida popularmente como vitória-régia, é marcada por sua beleza. Entretanto, sua biologia e as condições necessárias à germinação de suas sementes permanecem desconhecidas. Nesse estudo foram descritas a biometria e a morfologia do fruto e da semente, e avaliada a germinação em diferentes condições abióticas. Para isso, frutos de V. amazonica foram coletados em baias próximas ao rio Paraguai no Pantanal sul. Os frutos e as sementes foram descritos e mensurados usando paquímetro digital. Sementes íntegras e escarificadas mecanicamente foram submetidas a testes de germinação em diferentes condições de temperatura, luz e substrato, e o desenvolvimento inicial das plântulas foi descrito. Os frutos mediram 67,5 x 119,7 mm, e portavam 100-700 sementes. As sementes mediram 10,6 mm de comprimento e 9,8 mm de largura em média. A maior porcentagem de germinação ocorreu a 25oC independente da condição de luz. As sementes foram consideradas fotoblásticas neutras, e as plântulas possuem heterofilia, degeneração da raiz principal e formação de raízes adventícias. Foram observadas diferenças morfológicas nas plântulas desenvolvidas na presença e na ausência de luz.

Fruit and seed biometry and germination of Victoria amazonica (Poepp.) J.C. Sowerby (Nymphaeaceae) from the Pantanal floodplain / Biometria do fruto e da semente e germinação de Victoria amazonica (Poepp.) J.C. Sowerby (Nymphaeaceae) do Pantanal

Numerous plant species are easily established in the wide flood plains of the Pantanal wetlands due to the environmental heterogeneity. The aquatic macrophytes excel in permanently flooded areas, particularly Nymphaeaceae species. Victoria amazonica, popularly known as the vitória-régia, is hallmarked for its beauty. However, the biology and conditions necessary for the seed germination of this flowering plant remain unknown. In the present study, the fruit and seed morphology and biometry were described and the seed germination was evaluated under different abiotic conditions. To this end, mature fruits of V. amazonica were collected from the bays near Paraguay River in the south Pantanal floodplain. The fruits and seeds were described and measured using digital caliper. Intact and mechanically scarified seeds were germinated under different temperature, light and substratum conditions, and the initial development was described. The fruits measured 67.5 x 119.7 mm in size and contained 100-700 seeds. The average seed measured 10.6 mm in length and 9.8 mm in width. The highest germination occurred at 25o C, independent of the light condition. The seeds were considered neutral photoblastic. The seedlings showed heterophylly, and the main root was degenerated, forming adventitious roots. Morphological differences were observed in seedlings developed under different light conditions.(AU)

O Pantanal, ampla planície inundável, facilita o estabelecimento de inúmeras espécies vegetais por sua heterogeneidade ambiental. As macrófitas aquáticas se destacam em áreas permanentemente alagadas, com destaque para a família Nymphaeaceae. A espécie Victoria amazonica, conhecida popularmente como vitória-régia, é marcada por sua beleza. Entretanto, sua biologia e as condições necessárias à germinação de suas sementes permanecem desconhecidas. Nesse estudo foram descritas a biometria e a morfologia do fruto e da semente, e avaliada a germinação em diferentes condições abióticas. Para isso, frutos de V. amazonica foram coletados em baias próximas ao rio Paraguai no Pantanal sul. Os frutos e as sementes foram descritos e mensurados usando paquímetro digital. Sementes íntegras e escarificadas mecanicamente foram submetidas a testes de germinação em diferentes condições de temperatura, luz e substrato, e o desenvolvimento inicial das plântulas foi descrito. Os frutos mediram 67,5 x 119,7 mm, e portavam 100-700 sementes. As sementes mediram 10,6 mm de comprimento e 9,8 mm de largura em média. A maior porcentagem de germinação ocorreu a 25o C independente da condição de luz. As sementes foram consideradas fotoblásticas neutras, e as plântulas possuem heterofilia, degeneração da raiz principal e formação de raízes adventícias. Foram observadas diferenças morfológicas nas plântulas desenvolvidas na presença e na ausência de luz.(AU)