Antigenotoxic potential of plant leaf extracts of Parkinsonia aculeata L. using Allium cepa assay

Modulation of atrazine-induced chromosomal aberrations and cyclin-dependent kinases by aqueous extract of Roylea cinerea (D.Don) Baillon leaves in Allium cepa

Roylea cinerea (D.Don) Baillon an indigenous medicinal plant of Lamiaceae family used for the treatment of several diseases. In the present study, its aqueous (leaves) extract was tested for genoprotective action against atrazine-induced chromosomal aberrations in the root tip cells of Allium cepa. Atrazine is a herbicide of triazine class commonly used to inhibit the growth of broad leaf and grassy weeds. In order to find the concentration of atrazine that exhibits maximum toxicity, its different concentrations (1, 5 and 10 µg/mL) were tested. It was observed that 10 µg/mL concentration was more toxic as it reduced the mitotic index and also increased the chromosomal aberrations. Among all the tested concentrations of aqueous (leaves) extracts (0.25. 0.5, 1.0, 1.5 and 3.0 µg/mL), the3.0 µg/mL concentration in both modes of experiments i.e. pre and post showed a significant reduction in chromosomal aberrations induced by atrazine. To understand the mechanism of protection by plant extract on atrazine-induced chromosomal abnormalities the RT-qPCR studies were conducted to observe the expression of marker genes Cyclin-dependent kinases (CDKs) (CDKA:1, CDKB2:1 and CDKD1:1. For this, the RNA was extracted from root tips treated with extract along with atrazine by TRIzol^®. It was observed that aqueous extract of Roylea cinerea (D.Don) Baillon leaves upregulated the CDKs gene expression in both the modes i.e. pre and post treatments. A critical analysis of results indicated that aqueous extract ameliorated the chromosomal aberrations caused by atrazine which may be be due to the increased expression level of CDKs genes.

The chemical composition of different leaf extracts of Lantana fucata Lindl. influences its cytotoxic potential: A study using the Allium cepa model

ETHNOPHARMACOLOGICAL RELEVANCE

One of the most popular plants used to treat diseases in Brazil is Lantana fucata. Like most herbal medicines, its consumption is based on popular knowledge, which, despite being considered effective, may cause side effects.

AIM OF THE STUDY

Since the scientific data on the pharmacological properties of L. fucata are still incipient, this research aimed to evaluate the cytotoxic and genotoxic potential of different types of extracts (infusion, aqueous and hydroalcoholic), characterizing them chemically.

MATERIALS AND METHODS

The cytotoxicity assay was performed by the A. cepa model. The cytotoxicity parameters studied were number of dividing cells and percentage mitotic index (%MI).

RESULTS

The result of the A. cepa assay showed that there was a decrease in the number of dividing cells and the percentage mitotic index as concentrations increased, for all extracts, indicating cytotoxicity. However, the hydroalcoholic extract was the most cytotoxic. Chromatography analysis allowed the characterization of secondary metabolites in the extracts, which were very similar. However, a greater abundance of flavonoids and triterpenoids was observed in the hydroalcoholic extract, suggesting that these compounds are responsible for its greater toxicity.

CONCLUSIONS

Since the highest doses of extracts showed to have a cytotoxic effect, it is suggested that the ingestion of this species occurs in a moderate way.

Inonotus rickii (Agaricomycetes, Hymenochaetaceae) in Brazilian Cerrado: Expanding Its Geographic Distribution and Host List

Inonotus rickii (Pat.) Reid (Agaricomycetes: Hymenochaetaceae) is a poroid fungus characterized by the expressive production of chlamydospores, in vivo and in vitro, especially during its anamorphic stage. The species plays important ecological roles, standing out as a phytopathogen, affecting several species of ornamental and wild trees, mainly in tropical and subtropical regions. The infected trees develop canker and white rot of the wood, showing symptoms of reduced vegetative vigor and decline of leaves and branches which causes death in some cases. The first record of I. rickii for the Cerrado biome (Brazilian Savanna) and the first record as causal agent of canker in Schinus molle L. in Brazil is reported here. In addition, we present a checklist of its worldwide geographical distribution and known hosts, from an extensive bibliographic search in Google Scholar, SciELO, Scopus, and Web of Science databases. The species is widespread in tropical and subtropical zones; common in the American continent, especially in Central and South America and the Mediterranean region, and rare in temperate zones. We found specimens growing in both living and dead hosts, totalizing 70 species of hosts, distributed in 43 genera and 22 families. Of these, Acer negundo L. (10.5%), Celtis australis L. (6.5%), and Platanus acerifolia (Aiton) Willd. (4.8%), and the Fabaceae (30%), Fagaceae (10%), and Sapindaceae (8.6%) families were the most frequent. We present morphological descriptions and illustrations, as well as the growth characteristics in culture medium. Our study expands the known geographical distribution of I. rickii, including the Cerrado biome, as well as its structural, physiological characteristics, and its hosts.

Assessment of allelopathic, cytotoxic, genotoxic and antigenotoxic potential of Smilax brasiliensis Sprengel leaves

Smilax brasiliensis (Smilacaceae) is a native Brazilian plant found in the Cerrado biome and commonly used in folk medicine. The aim of this study was to evaluate the allelopathic, cytotoxic, genotoxic, and antigenotoxic potential of extract and fractions of Smilax brasiliensis leaves. Quercetin and rutin isomers were observed in the subfractions. The dichloromethane fraction (1000 μg/mL) decreased lettuce (Lactuca sativa) seed vigor, while and ethyl acetate and hydromethanol fractions (1000 μg/mL) affected the germination, and quercetin and rutin affected the vigor and germination of onion seeds. The extract, fractions, quercetin, and rutin inhibited or promoted lettuce hypocotyl and radicle growth. The extract and fractions inhibited onion hypocotyl growth at all concentrations. With regards to radicle growth, the results were diversified: growth was either inhibited or promoted. Rutin and quercetin inhibited onion hypocotyl and radicle growth at all concentrations. The extract and fractions of Smilax brasiliensis, rutin, and quercetin did not cause cytotoxic effect evaluated by mitotic index. The extract and fractions showed genotoxic effects. Quercetin and rutin did not cause genotoxic effects. On the other hand, the extract and fractions showed antigenotoxic effects at all tested concentrations, where they were able to revert chromosomal abnormalities caused by glyphosate. However, additional studies are required to evaluate the possible use of the S. brasiliensis leaf methanol extract and fractions as natural sources of bioherbicides.