Protective effect of kavain in meristematic cells of Allium cepa L.

Kavain is one of the main kavalactones of Piper methysticum (Piperaceae) with anxiolytic, analgesic, and antioxidant activities. Therefore, the aim of the study was to evaluate the cytotoxic, mutagenic, and antimutagenic potential of kavain in Allium cepa cells. Roots of A. cepa were transferred to the negative (2% acetone) and positive (10 µg/mL of Methylmethanesulfonate, MMS) controls and to the concentrations of kavain (32, 64 and 128 µg/mL) for 48 h. A total of 5,000 meristematic cells were analyzed under an optical microscope to determine the mitotic index, mean number of chromosomal alterations and percentage of damage reduction. Data were analyzed by Kruskal-Wallis test (p <0.05). All concentrations of kavain were not cytotoxic and did not show significant chromosomal changes when compared to 2% acetone. Kavain showed a cytoprotective effect in the pre (128 µg/mL) and in the post-treatment (32 and 64 µg/mL) and reduced damage against the mutagenic action of MMS in all concentrations of the pre and simultaneous and at the highest of post (128 µg/mL). Kavain promoted a significant reduction in micronuclei, nuclear buds and chromosomal losses in relation to MMS. The observed data indicate the importance of kavain for the inhibition of damage and chemoprevention.

Phytochemical prospecting, isolation, and protective effect of the ethanolic extract of the leaves of Jatropha mollissima (Pohl) Baill.

Jatropha mollissima is used in folk medicine as antimicrobial, antiparasitic, and larvicidal. However, few toxicogenetic studies have been carried out. Therefore, the aim of this study was to determine the phytochemical profile of ethanolic leaf extract of J. mollissima (EEJM) as well as potential cytotoxic, mutagenic, and antimutagenic properties. The EEJM was subjected to successive fractionation for the isolation of secondary metabolites, and five concentrations (0.01; 0.1; 1; 10 and 100 mg/ml) of extract were investigated using Allium cepa assay and the Somatic Mutation and Recombination (SMART) test. The mitotic index and % damage reduction were analyzed for A. cepa and the frequency of mutant hair for SMART. The presence of coumarins, alkaloids, flavonoids, saponins, and tannins was detected, while spinasterol and n-triacontane were the isolates identified for the first time for this species. EEJM did not exhibit cytotoxicity and was not mutagenic at 1 or 10 mg/ml using A. cepa and all concentrations of EEJM were not mutagenic in the SMART test. A cytoprotective effect was found at all concentrations. At 1 or 10 mg/ml EEJM exhibited antimutagenicity in A. cepa. In SMART, the protective effect was observed at 0.1 to 100 mg/ml EEJM. Our results demonstrate the important chemopreventive activity of EEJM, a desired quality in the search for natural anticarcinogenic compounds.

Phytochemical and antioxidant characterization, cytogenotoxicity and antigenotoxicity of the fractions of the ethanolic extract of in Poincianella bracteosa (Tul.) L.P. Queiroz.

POINCIANELLA BRACTEOSA: has been widely used in folk medicine to treat catarrhal infections, diarrhea, and anemia; however, phytochemical and toxicogenetic data are still lacking. The objective of this study was to examine the phytochemical and antioxidant characteristics as well as assess cytogenotoxicity and antigenotoxicity in hexane (HF), ether (EF) and ethyl acetate (AF) fractions of P. bracteosa leaves using Allium cepa bioassay. Phytochemical analysis revealed the presence of saponins and phenolic groups. EF fraction contained a higher content of total phenolics (441.23 ± 1.82 mg GAE/g), while HF fraction showed a higher content of total flavonoids (84.77 ± 5.33 mg QE/g). Higher antioxidant activity was observed in EF (EC50 25.06 ± 0.07 µg/ml). Cytotoxic effect was verified for all fractions, but no chromosomal alterations were observed in the A. cepa assay. With respect to antigenotoxicity, the protective effect of EF and AF fractions was attributed to as evidenced by the modulation of mutagenic action of methyl methanesulfonate (MMS), mainly by inhibiting the development of micronuclei. Among the fractions, EF was considered the most promising, as it exhibited higher antioxidant activity, was not genotoxic, exerted protective activity against the damage induced by MMS and also presented cytotoxic activity, a desired quality in the search for natural anticarcinogenic compounds.

Actividad antimutagénica e identificación de compuestos antioxidantes en la planta Poincianella bracteosa (Fabaceae)

Introducción: Poincianella bracteosa (Tul.) L.P. Queiroz. (Fabaceae), conocida como catingueira, es tradicionalmente utilizada en la medicina para tratar diarrea, hepatitis y anemia. Sin embargo, no hay estudios sobre los efectos tóxico genéticos de la P. bracteosa. Objetivo: En el presente estudio se tuvo como objetivo investigar el perfil fitoquímico y el potencial mutagénico y antimutagénico del extracto acuoso de la cáscara de P. bracteosa en Allium cepa y Mus musculus. Métodos: El extracto de la cáscara fue diluido en agua destilada para fornecer las cuatro concentraciones (2, 4, 8 y 16 mg/ml) utilizadas en el bioensayo A. cepa y las tres dosis (10, 20 y 40 mg / Kg) fueron administradas a los ratones (5 animales por grupo). El perfil fito-químico fue realizado por el test colorimétrico para identificar los principales metabólitos secundarios en el extracto de la cáscara. Tras el tratamiento, 5 000 células meristemáticas fueron analizadas para determinar el índice mitótico, el promedio de alteraciones cromosómicas y el porcentaje de reducción de daños. Para ratones, tras 24, 48 y 72 h, la sangre de la cola de cada animal fue recolectado para la preparación de dos láminas por animal. Para cada animal, 2 000 eritrocitos normocromáticos por ratón fueron evaluados para establecer el número de micronúcleos y el efecto protector. Se analizaron los dados por el test de Kruskal-Wallis (P < 0.05). El estudio fito-químico del extracto detectó azúcares reductores y taninos. Resultados: Ninguna de las concentraciones del extracto fue citotóxica y en todos los tratamientos (pre, simultáneo y después) fue observado el efecto citoprotetor en A. cepa. El promedio total de las alteraciones cromosómicas en todas las concentraciones apuntó actividad no mutagénica de la cáscara. El porcentaje de reducción del daño fue observada en los tratamientos pre (de 77.6 al 90.5 %), simultáneo (del 95.6 al 114.7 %) y tras (de 84.8 al 117.7 %). En los ratones, ninguna de las dosis del extracto presentó efecto mutagénico y el porcentaje de reducción del daño osciló de -21.2 al 78.6 % (pre); de 27.5 al 101.3 % (simultánea) y de 85.5 al 120.6 % (tras-tratamiento). Probablemente, los fito-químicos presentes en el extracto no interfirieron en el ciclo celular (A. cepa), tampoco causaron daños al DNA (A. cepa y ratones) y presentaron efecto protector en las dos especies estudiadas. Los datos observados apuntan la importancia del extracto de la cáscara de P. bracteosa para inhibición del daño y quimio prevención. Sin embargo, más estudios deben ser realizados para garantizar su efecto protector sobre el material genético.

Introduction: Poincianella bracteosa (Tul.) L.P. Queiroz. (Fabaceae), known as catingueira, is traditionally used in medicine to treat diarrhea, hepatitis and anemia. However, there are no studies on their toxicogenetic effects. Objective: The present study aimed to investigate the phytochemical profile as well as the mutagenic and antimutagenic potential of P. bracteosa aqueous bark extract in Allium cepa and Mus musculus. Methods: The extract from barks was diluted in distilled water to yield the four concentrations (2, 4, 8 and 16 mg/ml) used in the A. cepa bioassay and the three doses (10, 20 and 40 mg/Kg) administered to the mice (five animals per group). The phytochemical profile was performed by the colorimetric test to identify the main secondary metabolites in the bark extract. After treatment, five-thousand meristematic cells were analyzed to determine the mitotic index, the mean number of chromosome alterations and the percentage of damage reduction. For mice, after 24, 48 and 72 h, tail blood was collected from each animal for the preparation of two slides per animal. For each animal, 2 000 normochromatic erythrocytes per mice were evaluated to establish the number of micronuclei and the protective effect. Data were analyzed by Kruskal-Wallis test (P < 0.05). Results: The phytochemical analysis of the extract detected reducing sugars and tannins. None of the concentrations of extract was cytotoxic and the cytoprotective effect was observed in A. cepa for all treatments (pre-, simultaneous and post-). The total mean of chromosome alterations in all concentrations indicated a non-mutagenic activity of the bark. The percentage of damage reduction was observed in the pre- (77.6 to 90.5 %), simultaneous (95.6 to 114.7 %) and post- (84.8 to 117.7 %) treatments. In mice, none of the dosages of extract presented mutagenic effect and the percentage of damage reduction varied from -21.16 to 78.63 % (pre-); from 27.51 to 101.28 % (simultaneous) and from 85.47 to 120.63 % (post-treatment). Conclusions: Probably, the phytochemicals in the extract did not interfere with the cell cycle (A. cepa) nor caused damage to the DNA (A. cepa and mice), and exhibited protective effect in both studied species. The observed data indicate the importance of P. bracteosa bark extract for the inhibition of damage and chemoprevention. However, more studies should be carried out to ensure its protective effect on the genetic material.

Larvicidal, cytotoxic and genotoxic effects of aqueous leaf extract ofJatropha mollissima (Pohl) Baill / Efeitos larvicida, citotóxico e genotóxico do extrato aquoso das folhas de Jatrophamollissima (Pohl) Baill

The present study aimed to evaluate the larvicidal effect of aqueous leaf extract fromJatropha mollissima on the larvae of Aedes aegypti and analyze its cytotoxic and genotoxic activity in the Alliumcepa test. Larvae of the mosquito were exposed to the negative and positive controls (distilled water anddiflubenzuron, 0.003 mg mL-1, respectively) and to leaf extract concentrations of 0.001, 0.005, 0.01, 0.02,0.04, 0.06, 0.08 and 0.1 mg mL-1. The mortality rate was evaluated every 24 hours over five days. For thecytotoxic and genotoxic analyses, roots of A. cepa were exposed to the negative (distilled water) and positivecontrol (trifluralin, 0.84 ppm) and to different leaf extract concentrations (0.01, 0.1, 1 and 10 mg mL-1) for24 hours. The statistical analyses were performed by Kruskal-Wallis test (p < 0.05). The leaf extractpresented promising larvicidal activity at the concentrations of 0.08 and 0.1 mg mL-1, and none of theconcentrations evaluated in A. cepa exhibited cytotoxic or genotoxic effect. Since the larvicidal action of J.mollissima and the absence of cellular toxicity have been demonstrated, further studies are recommended todetermine the mechanism of action of the extract as a possible natural larvicide.

O presente estudo teve como objetivo avaliar o efeito larvicida do extrato aquoso das folhas deJatropha mollissima sobre as larvas de Aedes aegypti e analisar sua atividade citotóxica e genotóxica no testeAllium cepa. As larvas do mosquito foram expostas aos controles negativo e positivo (água destilada ediflubenzuron, 0,003 mg mL-1, respectivamente) e ao extrato foliar nas concentrações de 0,001; 0,005; 0,01;0,02; 0,04; 0,06; 0,08 e 0,1 mg mL-1. A taxa de mortalidade foi avaliada a cada 24horas durante cinco dias.Para as análises citotóxica e genotóxica, as raízes de A. cepa foram expostas ao controle negativo (águadestilada) e positivo (trifluralina, 0,84 ppm) e nas concentrações (0,01; 0,1; 1 e 10 mg mL-1) do extrato foliarpor 24 horas. Análises estatísticas foram realizadas pelo teste de Kruskal-Wallis (p < 0,05). O extrato foliarapresentou atividade larvicida promissora nas concentrações de 0,08 e 0,1 mg mL-1, e nenhuma dasconcentrações avaliadas em A. cepa exibiu efeito citotóxico ou genotóxico. Uma vez demonstrada a açãolarvicida de J. mollissima e a ausência de toxicidade celular, mais estudos são recomendados para determinaro mecanismo de ação do extrato como um possível larvicida natural.