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.

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.

Cytotoxic and genotoxic effects of ethanolic extract of Euphorbia hyssopifolia L. on HepG2 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Euphorbia hyssopifolia L. is a weed with recognized antimicrobial potential employed in Indian, Asian and Latin-American popular medicine. However, little is known with regard to its toxic potential. The present study aimed to investigate the cytotoxic and genotoxic effects of ethanolic extract of E. hyssopifolia in HepG2 cell culture. MATERIALS AND METHODS: Phytochemical screening of ethanolic extract was carried out to determine the presence of active secondary plant metabolites. Six concentrations (0.00001, 0.0001, 0.001, 0.01, 0.1 and 1.0mg/mL) of ethanolic extract were tested by the MTT assay to verify cytotoxicity. Then, genotoxic evaluations (alkaline comet assay and cytokinesis-block micronucleus assay - CBMN) were carried out in HepG2 cells with extract concentrations of 0.01, 0.1 and 1.0mg/mL. RESULTS: Mono and sesquiterpenes, triterpenes and steroids, and flavonoids were the main classes found in the phytochemical screening. Extract concentrations used in the MTT assay showed no cytotoxic activity. On the other hand, genotoxic activity was verified at 0.1 and 1.0mg/mL in the alkaline comet assay. Additionally, the 1.0mg/mL concentration induced severe cell damage leading to death in the CBMN assay, indicating a cytotoxic effect for this concentration in the latter method. CONCLUSION: The use of E. hyssopifolia extract for medicinal purposes should be avoided, because concentrations above 0.01mg/mL may pose risk to human health due to cytotoxic and/or genotoxic effects.