Evaluation of Protective Effects of Bioactive Phytochemicals Against Methotrexate in Salmonella typhimurium TA1535/pSK1002 Coupled with Micronucleus Assay / 生物医学与环境科学（英文）

We evaluated the antimutagenic effects of 10 kinds of bioactive phytochemicals and some phytochemical combinations against methotrexate (MTX)-induced genotoxicity by the umu test in Salmonella typhimurium TA1535/pSK1002 combined with a micronucleus assay. We observed that allicin, proanthocyanidins, polyphenols, eleutherosides, and isoflavones had higher antimutagenic activities than the other five types of bioactive phytochemicals. At the highest dose tested, MTX-induced genotoxicity was inhibited by 25%-75%. Kunming mice treated by MTX along with bioactive phytochemical combinations showed significant reduction in micronucleus induction and sperm abnormality rate (P<0.01). These results indicate that bioactive phytochemical combinations can be potentially used as new cytoprotectors.

Application of SOS/umu in screening cytoprotectors of plants against mitomycin C-induced genotoxic damage / 中草药

Objective: To establish a system and method for screening plant extract against mitomycin C-induced genotoxic damage. Methods: Salmonella typhimurium TA1535/pSK1002 and acute toxicity experiment of mice were used, and the effects of the extracts from ten plants, Chrysanthemis Flos, Allii Bulbus, Zingiberis Rhizoma Recens, Ginkgo Folium, Ginseng Radix et Rhizoma, Vitis Viniferae Semen, Gemmae Camelliae Sinensis Folium, Ganoderma, Acanthopanacis Senticosi Radix et Rhizoma seu Caulis, and Sojae Semen, and the extract combinations on mitomycin C-induced genotoxic damage were observed by SOS/umu test. Results: Significantly protective effects of five extracts, including the extracts from Allii Bulbus, Vitis Vindferae Semen, Gemmae Camelliae Sinensis Folium, Acanthopanacis Senticosi Radix et Rhizoma seu Caulis, and Sojae Semen against mitomycin C-induced genotoxicity were observed. Acanthopanacis Senticosi Radix et Rhizoma seu Caulis extract (1.5 g/L) could inhibit the mitomycin C-induced genotoxicity (67.12%). Combinations of any two extracts showed higher antimutagenic capacity than any single one. Among all the combinations, Acanthopanacis Senticosi Radix et Rhizoma seu Caulis-Gemmae Camelliae Sinensis Folium and Acanthopanacis Senticosi Radix et Rhizoma seu Caulis-Vitis Viniferae Semen showed the highest activity, and the inhibition rate of the former against the mitomycin C-induced genotoxicity was 83.2%. In vivo tests showed that Acanthopanacis Senticosi Radix et Rhizoma seu Caulis- Gemmae Camelliae Sinensis Folium could significantly decrease the micronucleus rate and sperm abnormality rate of mice induced by mitomycin C and also increase the thymus indexes. Conclusion: Based on the results, it is clearly proved that the SOS/umu is not only a useful and convenient way to evaluate the antimutagenic ability of plant extracts, but also could be used as a kind of rapid screening model for cytoprotector with high throughput screening of candidate extracts or compounds.

Studyies on the Breeding and Cultivation of L-Lactic Acid Producing Strain / 微生物学通报

In order to obtain higher L-lactic acid yield industrial strain, the original strain Rhizopus oryzae PW352 was mutated by means of N+ ions implantation and a mutant strain Rhizopus oryzae RE3303 was obtained. Its lactic acid yield was increased by 75% than that of the original one. The acid producing condition was optimized by orthogonal design. The concentration of L-lactic acid reached to 131～136g/L and the conversion rate of glucose was as high as 86%～90% under the optimum condition.