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.

Morphological analysis of vessel elements for systematic study of three Zingiberaceae tribes.

Zingiberaceae containing over 1,000 species that are divided into four subfamilies and six tribes. In recent decades, there has been an increase in the number of studies about vessel elements in families of monocotyledon. However, there are still few studies of Zingiberaceae tribes. This study aims to establish systematic significance of studying vessel elements in two subfamilies and three tribes of Zingiberaceae. The vegetative organs of 33 species processed were analysed by light and scanning electron microscopy and Principal Component Analysis was used to elucidate genera boundaries. Characteristics of vessel elements, such as the type of perforation plate, the number of bars and type of parietal thickening, are proved to be important for establishing the relationship among taxa. Scalariform perforation plate and the scalariform parietal thickening are frequent in Zingiberaceae and may be a plesiomorphic condition for this taxon. In the Principal Component Analysis, the most significant characters of the vessel elements were: simple perforation plates and partially pitted parietal thickening, found only in Alpinieae tribe, and 40 or more bars composing the plate in Elettariopsis curtisii, Renealmia chrysotricha, Zingiber spectabile, Z. officinale, Curcuma and Globba species. Vessel elements characters of 18 species of Alpinieae, Zingibereae and Globbeae were first described in this work.