The mutagenic and antimutagenic effects of the traditional phytoestrogen-rich herbs, Pueraria mirifica and Pueraria lobata

Pueraria mirifica is a Thai phytoestrogen-rich herb traditionally used for the treatment of menopausal symptoms. Pueraria lobata is also a phytoestrogen-rich herb traditionally used in Japan, Korea and China for the treatment of hypertension and alcoholism. We evaluated the mutagenic and antimutagenic activity of the two plant extracts using the Ames test preincubation method plus or minus the rat liver mixture S9 for metabolic activation using Salmonella typhimurium strains TA98 and TA100 as indicator strains. The cytotoxicity of the two extracts to the two S. typhimurium indicators was evaluated before the mutagenic and antimutagenic tests. Both extracts at a final concentration of 2.5, 5, 10, or 20 mg/plate exhibited only mild cytotoxic effects. The plant extracts at the concentrations of 2.5, 5 and 10 mg/plate in the presence and absence of the S9 mixture were negative in the mutagenic Ames test. In contrast, both extracts were positive in the antimutagenic Ames test towards either one or both of the tested mutagens 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide and benzo(a)pyrene. The absence of mutagenic and the presence of anti-mutagenic activities of the two plant extracts were confirmed in rec-assays and further supported by a micronucleus test where both plant extracts at doses up to 300 mg/kg body weight (equivalent to 16 g/kg body weight plant tuberous powder) failed to exhibit significant micronucleus formation in rats. The tests confirmed the non-mutagenic but reasonably antimutagenic activities of the two plant extracts, supporting their current use as safe dietary supplements and cosmetics.

Assessment of the mutagenic, antimutagenic and cytotoxic activities of ethanolic extract of araticum (Annona crassiflora Mart. 1841) by micronucleus test in mice

A typical Brazilian plant, araticum (Annona crassiflora Mart.), is widely used in humans as therapeutic medicine to treat several diseases such as diarrhea, rheumatism and syphilis. It contains acetogenins which present cytotoxic, antitumogenic, and antiparasitic properties. In this study, mutagenic, antimutagenic and cytotoxic effects of araticum leaves ethanolic extract were evaluated by micronucleus test in mice. To evaluate the mutagenic activity, animals were treated with ethanolic extract of araticum (EEA) using 10, 20, 50, 100 and 160 mg.kg-1. For all doses, micronucleated polychromatic erythrocytes (MNPCE) frequency was evaluated at 24, 48 and 72 hours after treatment. To evaluate the antimutagenic activity, animals were treated with 10, 20, 50 and 100 mg.kg-1 of EEA and 4 mg.kg-1 of MMC simultaneously. The frequency of MNPCE was evaluated 36 hours after exposure. Cytotoxicity was evaluated by the polychromatic and normochromatic erythrocytes ratio (PCE/NCE). In the mutagenicity assessment, all doses of EEA resulted in no significant increase of MNPCE (P > 0.05), compared to solvent- control group. Regarding administration time, no significant difference among three evaluation periods was observed (P > 0.05). Such results indicate that EEA did not exert mutagenic activity. Cytotoxicity was evident in doses of 50, 100 and 160 mg.kg-1 at 24 and 48 hours after exposure. Concerning antimutagenicity, except the 10 mg.kg-1 co-administered with 4 mg/kg of MMC, all doses reduced significantly the frequency of MNPCE compared to the positive control group (P < 0.05). These results, therefore, indicate an antimutagenic activity of the EEA. Cytotoxicity was significantly increased (P < 0.01) at 100 mg.kg-1 EEA doses co-administered with 4 mg.kg-1 of MMC.

O araticum (Annona crassiflora Mart.) é uma planta tipicamente brasileira, largamente utilizada em humanos como remédio para o tratamento de diversas doenças como diarréia, reumatismo e sífilis. Esta planta contém acetogeninas que apresentam propriedades citotóxica, antitumorigênica e antiparasitária. Neste estudo, foram avaliados os possíveis efeitos mutagênico, antimutagênico e citotóxico do extrato etanólico de folhas de araticum, pelo teste de micronúcleos em camundongos. Para a investigação da atividade mutagênica, os animais foram tratados com o extrato etanólico de araticum (EEA) utilizando 10, 20, 50, 100 e 160 mg.kg-1. Para todas as doses, as freqüências de eritrócidos policromáticos micronucleados (MNPCE) foram avaliadas em 24, 48 e 72 horas após o tratamento. Para a investigação da atividade antimutagênica, os animais foram tratados com 10, 20, 50 e 100 mg.kg-1 de EEA simultaneamente com 4 mg.kg-1 de MMC. A freqüência de MNPCE foi avaliada após 36 horas de exposição. A citotoxicidade foi avaliada pela razão de eritrócitos policromáticos e normocromáticos (PCE/NCE). Na avaliação da mutagenicidade, todas as doses de EEA não aumentaram significativamente o número de MNPCE (P > 0,05), comparativamente as do grupo solvente-controle. Em relação ao tempo de administração, não foi constatada diferença significativa entre os 3 períodos avaliados (P > 0,05). Esses resultados indicam que o EEA não exerceu atividade mutagênica.A citotoxicidade foi evidente nas doses de 50, 100 e 160 mg.kg-1 em 24 e 48 horas depois da exposição. Em relação à antimutagenicidade, exceto para a dose de 10 mg.kg-1 co-administrada com 4 mg.kg-1 de MMC, todas reduziram significativamente a freqüência de MNPCE, comparativamente as do grupo controle positivo (P < 0,05). Esses resultados, portanto, indicam uma atividade antimutagênica do EEA. A citotoxicidade foi significativamente aumentada (P < 0,01) na dose de 100 mg.kg-1 de EEA co-administrada com 4 mg.kg-1 de MMC.

Antimutagenic potential of ellagic acid isolated from Terminalia arjuna.

Antimutagenic potential of a fraction isolated from Terminalia arjuna has been evaluated in TA98 and TA100 strains of Salmonella typhimurium against direct and indirect-acting mutagens. The fraction was quite effective against S9-dependent 2AF while it showed moderate effect against NPD. The fraction was analyzed to be ellagic acid.

Antimutagenic effects of polyphenols isolated from Terminalia bellerica myroblan in Salmonella typhimurium.

Antimutagenic effect of 2 polyphenolic fractions isolated from T. bellerica in TA98 and TA100 strains of S. typhimurium against 2AF, NPD and 4NQNO has been characterized. Both the fractions were significantly effective against S9-dependent 2AF; less effective against NPD and almost not effective against 4NQNO in TA100 strain. Using 13C-NMR spectral analysis, the TB-3 fraction, which was significantly more effective against 2AF compared to TB-4, was found to be a mixture of 3 tannins while TB-4 was non-tannin fraction. Interaction of polyphenols with S9 proteins may be the probable cause of inhibitory effect of these polyphenols, though the possibility of other mechanisms cannot be ruled out.