Editorial for the Special Issue on “Brazilian Biodiversity”

Dear Reader,

It is my great pleasure to present this special issue dedicated to the study of Brazilian biodiversity.

Brazil is considered a megadiverse country, containing a large percentage of the worldʼs species. The Brazilian fauna and flora are distributed in a continental territory comprising six terrestrial biomes and three large marine ecosystems.

The struggle for life in these different biotopes leads to the production of an incredible chemical diversity by living organisms. This variety has already led to major drug discoveries in the past that revolutionized the world of medicine.

One example was the molecule tubocurarine, discovered from plants of the Chondrodendron genus, such as C. tomentosum Ruíz. & Pavón (Menispermaceae), and used for centuriues by indigenous communities as poison applied to arrowheads for hunting. It became the first drug used to relax skeletal muscles during surgery. Based on this discovery, chemists modified the structure of the natural compound to obtain the atracurium^® derivative, which is currently used in intensive care units around the world for mechanical ventilation of patients with COVID-19.

Another is Pilocarpine, an alkaloid isolated from the plant Pilocarpus jaborandi Holmes (Rutaceae), used to treat glaucoma and xerostomia. We can also mention game-changing drugs such as captopril (Capoten^®), enalapril (Vasotec^®), and lisinopril (Prinivil^®), developed based on the structure of the venom peptides of a Brazilian viper (Bothrops jarararaca) and currently used to control hypertension, symptomatic heart failure, and asymptomatic left ventricular dysfunction.

Unfortunately, most of these discoveries have been commercialized by multinational companies without benefits to the local population that often held the traditional knowledge that paved the way to these discoveries.

Even though a large majority of the worldʼs countries have signed the Convention on Biological Diversity (Nagoya Protocol), which recognizes the sovereign rights of states over their natural resources, a large part of the Brazilian population remains skeptical about the real importance of biodiversity for the development of their country. This can be explained by the fact that historically, Brazilians, in general, have always considered tropical forests as synonymous with backwardness.

Since its colonization by the Portuguese in the XVI^e century, the forest was systematically destroyed for the exploration of noble wood such as “Pau Brasil” (Caesalpinia echinata Lam, Fabaceae), the tree known to indigenous peoples as the source of a red pigment that gave the country its name. Later, gold and other valuable minerals drove colonization inland, creating more pressure on land as well as aquatic ecosystems. Later, in the XVI^e century, the destruction of forests accelerated as the land was cleared to make way for cattle ranching and large monoculture plantations of sugar cane where millions of slaves brought by force from Africa by the Portuguese worked until their death. This infamous crime was perpetrated for 300 years and enriched several European nations. It also marked the beginning of the hecatomb of the Brazilian Atlantic forest, considered a biodiversity hotspot and of which only 17% remains today.

Unfortunately, this colonial economic model based on the production of raw materials continues to this day. In the 1970s, boosted by a program organized by the dictatorial Brazilian government, the Amazon began to be systematically occupied and deforested. A symbol of this project was the construction of the monumental Trans-Amazon Highway that cuts through 4260 km of the jungle, linking the north of the country to the northeast. Its construction extended the tragedy of the indigenous peoples from this region who saw their forests disappear with the arrival of thousands of settlers. It is particularly important to highlight the continuous threat to these communities, who possess unique know-how in the use of plants and animals for the treatment of certain diseases. From an anthropological point of view, these people represent a unique perspective of human and social diversity, equally rich in its teachings and knowledge.

In recent decades, with the advent of soybean cultivation and intensive cattle farming, the pressure on the cerrado and Amazon basin ecosystems has reached alarming levels. The forest and savannah are disappearing at an unprecedented rate. For the past 2 years, Brazil has been burning due to unprecedented, uncontrollable forest fires. Despite protests from the international scientific community, nothing seems to stop the destruction of natural resources that are priceless to the country and the world.

In this context, for a conservation program to be successful, it must also be able to provide an economic return to Brazilian society in the short and medium term. It is essential to demonstrate that Brazilʼs sustainably exploited biodiversity will be able to stimulate the countryʼs economic growth and social inclusion.

This special issue presents a series of reviews and articles highlighting exciting research programs related to the search for bioactive compounds from medicinal plants, fungi, and marine organisms in different universities in Brazil. These programs are also responsible for the training of a significant number of young researchers in the fields of botany, the chemistry of natural products (pharmacognosy), and biology. All the scientific work presented below represents hope for the future of Brazil, because science and education are the only way to break the “status quo” and open new fields of knowledge that will provide answers on how to sustainably explore the countryʼs biodiversity.

An excellent example of a research project devoted to solving a major Brazilian problem using its biodiversity is described in the article by Bolzani and collaborators. Due to the explosion in the number of cases of imported tropical diseases in recent years, the fight against the invasive mosquito Aedes aegypti has become a priority for the Brazilian government. To control the mosquito, Bolzani et al. propose an article describing a strategy based on a large and rational screening of Brazilian flora, particularly from the Brazilian Cerrado, to find compounds against A. aegypti.

The complex ecological relationships between insects and microbes constitute the main topic of an interesting research article presented by Pupo and co-workers. Ants and termites have used antibiotics for millions of years before humans. This promising subject may soon give new drugs against bacteria that are multiresistant to conventional antibiotics. The authors also highlight the importance of public policies for insect biodiversity preservation. The interactions between insects and plants are presented in the article proposed by Lopes et al., where time frame emissions surveys of volatile compounds are analyzed in wild specimens of Brazilian arnica (Lychnophora ericoides Mart., Asteraceae). In parallel, for the first time, pollinators such as hummingbirds, hemiptera insects, and wasps were recorded visiting the flowers.

Tropical forests are the reservoir of a huge collection of microorganisms such as fungi. In this highly competitive environment, microorganisms fight for their lives by producing chemical weapons against their competitors. Reproducing this environment in the laboratory is essential for the discovery of bioactive compounds. This is the subject of the article by Vieira et al. proposing a co-culture of tropical fungal species to triggering activation of silent biosynthetic gene clusters responsible for the biosynthesis of active metabolites. Using this approach, the authors identified antibacterial and antiparasitic compounds against Trypanosoma cruzi and Leishmania infantum.

In 2004, the concept of “Blue Amazon” was established by the Brazilian Navy”. It referred to an ocean area of 5.7 million km² within the Brazilian territorial waters. While the Amazon rainforest is the stage of all human attention, the blue Amazon made up of paradisiacal beaches, coral reefs, and deep sea is still little explored. In their article, Lotufo-Costa et al. present an extensive overview of compounds isolated from Brazilian marine organisms in the last 40 years with potential anticancer activity. The authors also discuss the most promising compounds isolated from sponges, cnidarians, ascidians, and microbes in terms of their molecular targets and mechanisms of action.

Finally, a variety of articles highlighting the relevance of Brazilian medicinal plants as resources of bioactive compounds, such as the article of Lopes et al., offer an overview of plants from the Compositae family growing in Brazil possessing anti-inflammatory activities. Soares et al. propose a very interesting article describing the in vitro and in vivo immunomodulatory study of Physalis angulata L. (Solanaceae) ethanolic extract. In conclusion, the authors suggest its use as an alternative way for the treatment of immune-inflammatory diseases. De Souza and co-workers propose an extensive literature survey on the main Brazilian medicinal plants used as diuretics. Additionally, Oliva et al. describe the protease inhibitors that attenuate gastric ulcers obtained from plants of the Bauhinia genus (Caesalpinioideae).

The sustainability of natural resources is also an important topic. The article of Pessoa et al. describes the cultivation and the phytochemical study of the medicinal plant Plectranthus ornatus Cood, Lamiaceae, while Brandt Giordani propose a study of the chemical diversity of flavonoids and selaginellins in the medicinal plant Selaginella convolute (Arn.) Spring (Selaginellaceae) using state-of-the-art analytical approaches such as the molecular network. The same group describes the alkaloidal content of Erythroxylum pungens O. E. Schulz (Erythroxylaceae) and its toxicity profile using a zebrafish assay. Bueno et al. describe the intraspecific chemical variability and biological activity of Casearia sylvestris Eichler (Salicaceae) in different Brazilian biomes. Finally, Lopes et al. describe the biosynthesis of bioactive compounds in Tabernaemontana catharinensis A.DC. (Apocynaceae) and its importance for the development of drugs against Alzheimerʼs disease.

This special issue illustrates the relevance and importance of Brazilian biodiversity as a source of bioactive compounds. It also reveals that, despite the economic difficulties experienced in recent years, exacerbated by a lack of support from the current government, researchers in various regions have been able to continue their research work and training Brazilʼs young research generation for the future. The preservation of this magnificent natural heritage begins with the education of the population and its politicians.

I would like to warmly thank the authors of this special issue for their excellent contributions. I would also like to thank the editor in chief, Prof. Robert Fürst, associate editor Prof. Jose-Luis Rios, and the many anonymous reviewers for their time and expertise in evaluating the manuscripts. I would also like to thank Mr. Fernando Zharur (UNICEF, Switzerland) and Ms. Renata C. Nogueira (Antenna technologies, Switzerland) for the rich discussions about Brazilian biodiversity. I hope that the scientific community will find this special issue on Brazilian biodiversity exciting to read and that it will serve as a high-quality scientific reference.

Dr. Emerson Ferreira Queiroz
Guest editor

Conflict of Interest

The authors declare that they have no conflict of interest.