Assessment of the antioxidant, cytotoxic, and genotoxic potential of the Annona muricata leaves and their influence on genomic stability.

The popular use of Annona muricata L. is based upon a range of medicinal purposes, and the plant exhibits biological activities including antihyperglycemic, antiparasitic, and antitumor activities. The objectives of this study were to examine the antioxidant, cytotoxic, and genotoxic potential of the hydroalcoholic extract of A. muricata leaves (AMEs), as well as its effects on genotoxicity induced by methyl methanesulfonate (MMS) and hydrogen peroxide (H2O2). The results using 2,2-diphenyl-1-picrylhydrazyl assay showed that AME was able to scavenge 44.71% of free radicals. The extract significantly reduced the viability of V79 cells in the clonogenic assay at concentrations ≥8 µg/ml. No significant differences in micronucleus (MN) frequency were observed between V79 cell cultures treated with different concentrations of the extract (0.125, 0.25, 0.5, and 1 µg/ml) and negative control. When AME concentrations were combined with MMS, data revealed no marked differences from mutagen alone. In contrast, significant reductions in the frequencies of MN were noted in cultures treated with AME combined with H2O2 compared to H2O2 alone. In vivo studies found no significant differences in the frequencies of micronucleated polychromatic erythrocytes (MNPCEs) between animals treated with different AME doses compared to control. Animals treated with AME doses of 125 and 250 mg/kg and MMS exhibited significantly higher frequencies of MNPCE compared to mutagen alone. In conclusion, under current experimental conditions, AME was not genotoxic and exerted a modulatory effect on DNA damage depending upon the experimental conditions. The extract did not influence markedly MMS-induced genotoxicity in in vitro test system. However, the extract increased DNA damage induced by mutagen in mice. In V79 cells, AME reduced the genotoxicity produced by H2O2, and this protective effect was attributed in part to the antioxidant activity of AME.

In vitro cytotoxicity, genotoxicity and antigenotoxicity assessment of Solanum lycocarpum hydroalcoholic extract.

CONTEXT: Solanum lycocarpum A. St.-Hil. (Solanaceae), popularly known as 'fruta-do-lobo' (wolf fruit), 'lobeira' and 'jurubebão', is commonly used by native people of Central Brazil in powder form or as a hydroalcoholic extract for the management of diabetes and obesity and to decrease cholesterol levels. OBJECTIVE: The present study determines the possible cytotoxic, genotoxic and antigenotoxic activities of hydroalcoholic extract of the S. lycocarpum fruits (SL). MATERIALS AND METHODS: The clonogenic efficiency assay was used to determine the cytotoxicity. Three concentrations of SL (16, 32 and 64 µg/mL) were used for the evaluation of its genotoxic and antigenotoxic potential on V79 cells using the micronucleus and comet assays. In the antigenotoxicity assays, the cells were treated simultaneously with SL and the alkylating agent methyl methanesulphonate (MMS, 44 µg/mL for the micronucleus assay and 22 µg/mL for the comet assay) as an inducer of micronuclei and DNA damage. RESULTS: The results showed that SL was cytotoxic at concentrations up to 64 µg/mL. No significant differences in the rate of chromosome or DNA damage were observed between cultures treated with SL and the control group. In addition, the frequencies of micronuclei and DNA damage induced by MMS were significantly reduced after treatment with SL. The damage reduction percentage ranged from 68.1% to 79.2% and 12.1% to 16.5% for micronucleus and comet assays, respectively. DISCUSSION AND CONCLUSION: SL exerted no genotoxic effect and exhibited chemopreventive activity against both genomic and chromosome damage induced by MMS.

In vivo protective activity of Styrax camporum hydroalcoholic extract against genotoxicity induced by doxorubicin and methyl methanesulfonate in the micronucleus and comet assays.

Styrax camporum Pohl is a tall shrub or a tree with small white flowers, which grows in the states of São Paulo and Minas Gerais and is popularly used for the treatment of gastroduodenal diseases. Considering this last fact, the aim of this study was to evaluate the genotoxic potential of S. camporum hydroalcoholic extract and its influence on genotoxicity induced by doxorubicin and methyl methanesulfonate in Swiss mice using the micronucleus and comet assays, respectively. The animals were treated by gavage with different doses of the extract (250, 500, and 1000 mg/kg body weight). For antigenotoxicity assessment, different doses of the S. camporum extract were administered simultaneously with doxorubicin (micronucleus test; 15 mg/kg) and methanesulfonate (comet assay; 40 mg/kg). The results showed that the S. camporum extract itself was not genotoxic in the mouse micronucleus or comet assay. The number of micronucleated polychromatic erythrocytes was significantly lower in animals treated with the S. camporum extract and doxorubicin when compared to animals treated only with doxorubicin. In the comet assay, the S. camporum extract, at the doses tested, significantly reduced the extent of DNA damage in liver cells induced by methanesulfonate. The putative activity of the active compounds of S. camporum extract may explain the effect of this plant on genotoxicity induced by doxorubicin and methanesulfonate.

Toxicogenetic study of Persea americana fruit pulp oil and its effect on genomic instability.

Persea americana Mill., commonly known as avocado, is a tree native to Central America that is widely used as a food source and for the treatment of diseases. This plant has various biological properties such as analgesic, anti-inflammatory and total cholesterol-lowering activity. In view of its pharmacological potential, we conducted a toxicogenetic study of the fruit pulp oil of P. americana (PAO) and investigated its influence on genotoxicity induced by methyl methanesulfonate (MMS) and doxorubicin. V79 cells and Swiss mice were used for the assays. The results showed no genotoxic effects of PAO in the in vitro or in vivo test systems. However, the highest PAO dose tested led to an increase in the levels of aspartate aminotransferase, indicating hepatic/tissue damage. This effect may be related to high concentrations of palmitic acid, the main component of PAO. Furthermore, PAO was effective in reducing the chromosome damage induced by MMS and doxorubicin. These results contribute to the safety assessment of PAO as a medicinal plant for human use.