Toxic Potential of Cerrado Plants on Different Organisms.

Cerrado has many compounds that have been used as biopesticides, herbicides, medicines, and others due to their highly toxic potential. Thus, this review aims to present information about the toxicity of Cerrado plants. For this purpose, a review was performed using PubMed, Science Direct, and Web Of Science databases. After applying exclusion criteria, 187 articles published in the last 20 years were selected and analyzed. Detailed information about the extract preparation, part of the plant used, dose/concentration tested, model system, and employed assay was provided for different toxic activities described in the literature, namely cytotoxic, genotoxic, mutagenic, antibacterial, antifungal, antiviral, insecticidal, antiparasitic, and molluscicidal activities. In addition, the steps to execute research on plant toxicity and the more common methods employed were discussed. This review synthesized and organized the available research on the toxic effects of Cerrado plants, which could contribute to the future design of new environmentally safe products.

Phytochemical Composition and Protective Effect of Vernonanthura polyanthes Leaf against In Vivo Doxorubicin-Mediated Toxicity.

Vernonanthura polyanthes (Spreng.) A.J. Vega & Dematt. (syn.: Vernonia polyanthes Less) is popularly known as "assa-peixe" and its leaves are used in folk medicine mainly to treat respiratory diseases. In this study, we evaluated the cytogenotoxic and anticytogenotoxic potential of the V. polyanthes leaf aqueous extract (VpLAE) and its n-butanol fraction (n-BF) in the presence or absence of doxorubicin (DXR) (pre-, co-, and post-treatments) on a murine model for 24 h or 120 h. The micronucleus test (MN) and the comet assay were used to assess the cytogenotoxic and anticytogenotoxic potential of VpLAE and n-BF (250, 500, and 1000 mg/kg) administered via gavage to Swiss Webster mice. The chemical profiles of VpLAE and n-BF were assessed by liquid chromatography coupled to mass spectrometry, and their metabolites were putatively identified. Lastly, the possible biological activities related to the (anti) cytogenotoxicity of the compounds were predicted using the PASS online webserver. The in vivo results showed that different doses of VpLAE and n-BF did not present cytotoxic activity; however, the MN test revealed a slight mutagenic activity for the 24 h treatments. Moderate genotoxic effects were demonstrated for all treatments in the comet assay. Regarding anticytotoxicity and antimutagenicity, VpLAE and n-BF presented a high cytoprotective potential against DXR toxic effects. In the co-treatment, VpLAE reduced the DXR genotoxicity by ~27%, and n-BF did not demonstrate antigenotoxic potential. In contrast, an antigenotoxic effect was observed for both VpLAE and n-BF in the pre- and post-treatments, reducing DXR genotoxicity by ~41% and ~47%, respectively. Chemical analysis of VpLAE and n-BF showed the presence of eight phenolic compounds, including seven chlorogenic acids and a flavonoid. The PASS online tool predicted antimutagenic, anticancer, antineoplastic, chemoprotective, antioxidant, and radical scavenging activities for all constituents identified in VpLAE and n-BF. V. polyanthes leaves presented a protective effect against DXR cytogenotoxicity. In general, VpLAE and n-BF showed a greater antigenotoxic potential in the pre- and post-treatments. The metabolites putatively identified in VpLAE and n-BF exhibited antioxidant and chemoprotective potential according to computational prediction analysis. Altogether, our results highlight the potential application of V. polyanthes to protect against toxic manifestations induced by DXR.

In vitro hematotoxicity of Vernonanthura polyanthes leaf aqueous extract and its fractions.

Vernonanthura polyanthes, popularly known as 'assa-peixe', is widely used in Brazil for therapeutic purpose mainly to treat respiratory tract problems. However, few studies investigated its chemical safety. In this way, we first obtained the V. polyanthes leaf aqueous extract (VpLAE) and three fractions (aqueous; n-butanol, n-BF; and ethyl acetate), and we chemically characterized this material. Then, the cytogenotoxic potential of the VpLAE and its fractions was investigated against human erythrocytes and lymphocytes using Trypan blue exclusion test of cell viability and CometChip. The phytochemical screening of V. polyanthes leaf revealed the presence of total phenolic compounds, flavonoids, tannins, coumarins, terpenic compounds, and cardioactive heterosides. n-BF presented the highest total phenolic, flavonoids, and tannins contents and, consequently, the highest antioxidant activity, according to the DPPH free radical scavenging method. Although the VpLAE and its fractions did not cause death of erythrocytes, the cells acquired an echinocytic form. Regarding lymphocytes, VpLAE and its fractions presented cytotoxicity and genotoxicity. When VpLAE or its fractions were co-treated with doxorubicin (DXR), a recognized cytotoxic drug, we observed an enhancement of DXR cytotoxicity against lymphocytes, but the DXR genotoxicity decreased around 15%. Since the VpLAE and its fractions increased the DXR cytotoxicity and decreased its genotoxicity, further studies should be conducted for the development of an adjuvant drug from this extract to reduce the side effects of chemotherapy. Moreover, the indiscriminate use of 'assa-peixe' by local people should be discouraged.