Patenting bioactive molecules from biodiversity: the Brazilian experience

A Kunitz-type inhibitor from tick salivary glands: A promising novel antitumor drug candidate

Salivary glands are vital structures responsible for successful tick feeding. The saliva of ticks contains numerous active molecules that participate in several physiological processes. A Kunitz-type factor Xa (FXa) inhibitor, similar to the tissue factor pathway inhibitor (TFPI) precursor, was identified in the salivary gland transcriptome of Amblyomma sculptum ticks. The recombinant mature form of this Kunitz-type inhibitor, named Amblyomin-X, displayed anticoagulant, antiangiogenic, and antitumor properties. Amblyomin-X is a protein that inhibits FXa in the blood coagulation cascade and acts via non-hemostatic mechanisms, such as proteasome inhibition. Amblyomin-X selectively induces apoptosis in cancer cells and promotes tumor regression through these mechanisms. Notably, the cytotoxicity of Amblyomin-X seems to be restricted to tumor cells and does not affect non-tumorigenic cells, tissues, and organs, making this recombinant protein an attractive molecule for anticancer therapy. The cytotoxic activity of Amblyomin-X on tumor cells has led to vast exploration into this protein. Here, we summarize the function, action mechanisms, structural features, pharmacokinetics, and biodistribution of this tick Kunitz-type inhibitor recombinant protein as a promising novel antitumor drug candidate.

Evidence of traditionality of Brazilian medicinal plants: The case studies of Stryphnodendron adstringens (Mart.) Coville (barbatimão) barks and Copaifera spp. (copaíba) oleoresin in wound healing

ETHNOPHARMACOLOGICAL RELEVANCE

The World Health Organization (WHO) recognizes the potential of plants used in secular traditional medicine and considers this an important source of evidence to assess their effectiveness and safety. Brazil is rich in biodiversity and traditional uses based on the Amerindian culture. However, many processes started with the arrival of the Portuguese in the year 1500. The successive economic cycles, for example, led to destruction of native vegetation and an intense cultural erosion. As a consequence, the information about the use of plants in the past centuries are dispersed and without interpretation. In this study a methodology to evidence the traditionality of Brazilian plants was demonstrated using data about barbatimão barks (Stryphnodendron adstringens (Mart.) Coville - Fabaceae) and Copaiba oleoresin (Copaifera spp. - Fabaceae) in wound healing, was established.

MATERIAL AND METHODS

Data about use of the plants were recovered from bibliography published between 1576 and 2011. The books (101) were classified using weights, considering the date of publication and the source of Information. Older books that describe primary information received weight 10, while books written more recently and with secondary information received weight 0.4. A score for each category of medicinal use was calculated based on the books weights and the frequency of citation. A review about the current use of both plants was also performed from ethnobotanical studies published in journals.

RESULTS AND DISCUSSION

The traditional secular use of barks of barbatimão and oleoresin of copaiba to treat wounds was confirmed based on the historic bibliographic research. The most frequent use of barbatimão in a timeline of 500 years of Brazil's history, was as astringent, whereas for copaíba was as healing of skin and mucosal lesions. The continuous and current use of these plants to treat wounds, confirmed by recent ethnobotanical studies, is an indicative of the resilience of these remedies and their effectiveness.

CONCLUSION

The use of preparations containing barbatimão barks and copaiba oleoresin can be considered effective in the treatment of wounds. Nonetheless, it is necessary to improve the quality of the formulas as established by WHO.

Stryphnodendron Species Known as "Barbatimão": A Comprehensive Report

Stryphnodendron spp., popularly known as "barbatimão", is the native Brazilian tree most often employed to treat wounds and infections. The aim of the present study was to highlight the importance of S. adstringens, as well as other Stryphnodendron species recognized as "barbatimão", to human health, depicting the relevance of ethnopharmacological knowledge to scientific evidence for uses, related chemical compounds, development of pharmaceutical formulations, and the establishment of toxicity parameters. For this purpose, the literature databases PubMed, Scielo, Lilacs, CAPES Thesis and Google Scholar were searched until 2017. It was observed that stem bark was the primary part of the plant used, mainly as a decoction, for wound healing and treatment of infectious and inflammatory disorders. Confirmed biological activities, including wound healing, anti-inflammatory, antioxidant, and antimicrobial activities, were related to the presence of compounds from tannin class, mostly proanthocyanidins. Toxicity parameters for stem bark were inconclusive, but toxicity was observed to a significant extent when seeds were ingested by cattle or other animals. Due to these important and confirmed biological activities, government policy encourages the phytotherapic use of S. adstringens, and some formulations with stem bark extracts were developed and patented. Furthermore, antiprotozoal, hypoglycemic and antiviral activities were identified as promising.

Evaluation of cytogenotoxicity, antioxidant and hypoglycemiant activities of isolate compounds from Mansoa hirsuta D.C. (Bignoniaceae)

Mansoa hirsuta (Bignoniaceae) is a native plant from caatinga in Brazilian semiarid. This plant has been locally used as antimicrobial and hypoglycemiant agents, but their action mechanisms and toxicity remain largely unknown. Therefore, we evaluated the composition and antioxidant, cytoprotective and hypoglycemiant effects of raw extract, fractions and compounds from leaves of M. hirsuta. The cytogenotoxic effects of ursolic and oleanolic acids, the main phytotherapic components of this plant, were assessed. The raw extract and fractions presented steroids, saponins, flavonols, flavanonols, flavanones, xanthones, phenols, tannins, anthocyanins, anthocyanidins and flavonoids. The ethyl acetate fraction inhibited efficiently the cascade of lipid peroxidation while the hydroalcoholic fraction was richer in total phenols and more efficient in capturing 2,2-diphenyl-1-picrylhydrazyl (·DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS·+) radicals. The isolated fraction of M. hirsuta also inhibited the α-amylase activity. Cytotoxic effects were absent in both raw extract and fractions while ursolic+oleanolic acids were efficient in protecting cells after exposure to hydrogen peroxide. Moreover, this mixture of acid shad no significant interference on the mitotic index and frequency of nuclear and/or chromosomal abnormalities in Allium cepa test. Therefore, M. hirsuta represents a potential source of phytochemicals against inflammatory and oxidative pathologies, including diabetes.

Land-use and climate change risks in the Amazon and the need of a novel sustainable development paradigm

For half a century, the process of economic integration of the Amazon has been based on intensive use of renewable and nonrenewable natural resources, which has brought significant basin-wide environmental alterations. The rural development in the Amazonia pushed the agricultural frontier swiftly, resulting in widespread land-cover change, but agriculture in the Amazon has been of low productivity and unsustainable. The loss of biodiversity and continued deforestation will lead to high risks of irreversible change of its tropical forests. It has been established by modeling studies that the Amazon may have two "tipping points," namely, temperature increase of 4 °C or deforestation exceeding 40% of the forest area. If transgressed, large-scale "savannization" of mostly southern and eastern Amazon may take place. The region has warmed about 1 °C over the last 60 y, and total deforestation is reaching 20% of the forested area. The recent significant reductions in deforestation-80% reduction in the Brazilian Amazon in the last decade-opens up opportunities for a novel sustainable development paradigm for the future of the Amazon. We argue for a new development paradigm-away from only attempting to reconcile maximizing conservation versus intensification of traditional agriculture and expansion of hydropower capacity-in which we research, develop, and scale a high-tech innovation approach that sees the Amazon as a global public good of biological assets that can enable the creation of innovative high-value products, services, and platforms through combining advanced digital, biological, and material technologies of the Fourth Industrial Revolution in progress.

Useful Brazilian plants listed in the manuscripts and publications of the Scottish medic and naturalist George Gardner (1812-1849)

ETHNOPHARMACOLOGICAL RELEVANCE

Information regarding the beneficial use of native Brazilian plants was compiled by a number of European naturalists in the 19th century. The Scottish surgeon botanist George Gardner (1812-1849) was one such naturalist; however, the useful plants recorded in his manuscripts have not yet been studied in depth.

AIM OF THE STUDY

To present data recorded by Gardner in his manuscript Catalogue of Brazilian Plants regarding the use of native plants by Brazilian people and evaluate the extent to which they have been explored.

MATERIALS AND METHODS

Data on useful plants were obtained from Gardner׳s manuscript Catalogue of Brazilian Plants deposited in the Archives of the Royal Botanic Gardens, Kew, UK. The identification of each plant was determined and/or updated by consulting the preserved botanical collections of Gardner deposited in the Herbarium of the Royal Botanic Gardens, Kew (hereafter K), and expert determinations in other herbaria where duplicates are held. Correlated pharmacological studies for each plant were obtained from the PubMed database. Information recorded in Gardner׳s diary and previously published elsewhere complemented these data.

RESULTS

A total of 63 useful plants was recorded from the Catalogue and a further 30 from Gardner׳s book Travels in the Interior of Brazil (Gardner, 1846). Of the recorded names in the Catalogue, 46 (73%) could be identified to species by consulting specimens collected by Gardner and held at Kew. Thirty-six different traditional uses were registered for the identified plants, the most common being as febrifuges, to treat venereal complaints and as purgatives. Fewer than 50% of these species have been the focus of published pharmacological studies, yet for those which have been thus investigated, the efficacies reported by Gardner were confirmed.

CONCLUSION

The data recorded by Gardner represent a rich, relatively unexplored source of information regarding the traditional uses of Brazilian plants which merits further investigation.

The use of an integrated molecular-, chemical- and biological-based approach for promoting the better use and conservation of medicinal species: a case study of Brazilian quinas

ETHNOPHARMACOLOGICAL RELEVANCE

Quina is a popular name originally attributed to Cinchona pubescens Vahl (=Cinchona succirubra) and Cinchona. calisaya Wedd., species native from Peru that have the antimalarial alkaloid quinine. In Brazil, bitter barks substitutes for the Peruvian species began to be used centuries ago, and they still are sold in popular markets. To assess the authenticity and the conditions on which samples of quinas have been commercialized, using the DNA barcode, chemical and biological assays.

MATERIALS AND METHODS

Starting with 28 samples of barks acquired on a popular market, 23 had their DNA extracted successfully. The regions matK and rbcL were amplified and sequenced for 15 and 23 samples, respectively. Phytochemical analyses were performed by chromatographic methods, and biological essays were done by antimalarial tests in vitro.

RESULTS

The identified species belonged to six different families, many of them endangered or with no correlation with use in traditional medicine as a Brazilian quina. The absence of typical bitter chemical substances indicated that barks have been collected from other species or from very young trees. The results of biological essays confirm the lack of standardization of the sold materials.

CONCLUSION

The integrated approaches proved to be efficient to evaluate medicinal plants sold in popular markets and can be useful for promoting their better use and conservation.

Antinociceptive effect of Lecythis pisonis Camb. (Lecythidaceae) in models of acute pain in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Lecythis pisonis Camb., also known in Brazil as sapucaia, is used in folk medicine against pruritus, muscle pain and gastric ulcer.

AIM OF THE STUDY

To investigate the antinociceptive effect of ethanol extract from Lecythis pisonis leaves (LPEE), fractions (hexane-LPHF, ether-LPEF and ethyl acetate-LPEAF) and mixture of triterpenes [ursolic and oleanolic acids (MT)] in mice.

MATERIALS AND METHODS

LPEE and LPEF were evaluated on the acetic acid induced writhings and formalin, capsaicin and glutamate tests. In addition, MT was investigated on the writhings induced by acetic acid, capsaicin and glutamate tests. In the study of some possible mechanisms involved on the antinociceptive effect of LPEF, it was investigated the participation of opioid system, K+ATP channels and L-arginine-nitric oxide pathway.

RESULTS

LPEE (12.5 and 25 mg/kg, p.o.), LPEF and MT (6.25, 12.5 and 25 mg/kg, p.o.) reduced the writhings in comparison to saline. LPEE (100 mg/kg, p.o.) and LPEF (50 mg/kg, p.o.) were effective in inhibiting both phases of formalin test. In capsaicin test, LPEE (100 and 200 mg/kg, p.o.), LPEF (12.5-50 mg/kg, p.o) and MT (6.25-25 mg/kg, p.o.) showed a significant antinociceptive effect compared to the control. LPEE (25 and 50 mg/kg, p.o.), LPEF (50 and 100 mg/kg, p.o.) and MT (12.5 and 25 mg/kg, p.o.) reduced the glutamate-evoked nociceptive response. Treatment with naloxone, L-arginine and glibenclamide reversed the effect of LPEF in glutamate test.

CONCLUSIONS

These results indicate the antinociceptive effect of Lecythis pisonis leaves and suggest that this effect may be related to opioid pathway, K+ATP channels, and L-arginine-nitric oxide modulation. Furthermore, these data support the ethnomedical use of this plant.

Rationale for a natural products approach to herbicide discovery

Weeds continue to evolve resistance to all the known modes of herbicidal action, but no herbicide with a new target site has been commercialized in nearly 20 years. The so-called 'new chemistries' are simply molecules belonging to new chemical classes that have the same mechanisms of action as older herbicides (e.g. the protoporphyrinogen-oxidase-inhibiting pyrimidinedione saflufenacil or the very-long-chain fatty acid elongase targeting sulfonylisoxazoline herbicide pyroxasulfone). Therefore, the number of tools to manage weeds, and in particular those that can control herbicide-resistant weeds, is diminishing rapidly. There is an imminent need for truly innovative classes of herbicides that explore chemical spaces and interact with target sites not previously exploited by older active ingredients. This review proposes a rationale for a natural-products-centered approach to herbicide discovery that capitalizes on the structural diversity and ingenuity afforded by these biologically active compounds. The natural process of extended-throughput screening (high number of compounds tested on many potential target sites over long periods of times) that has shaped the evolution of natural products tends to generate molecules tailored to interact with specific target sites. As this review shows, there is generally little overlap between the mode of action of natural and synthetic phytotoxins, and more emphasis should be placed on applying methods that have proved beneficial to the pharmaceutical industry to solve problems in the agrochemical industry.