RESUMEN
Objective To study the anti-tumor effects of alcohol extraction of Coix stalk objects on H22 tumor-bearing mice. Methods The animal model of tumor bearing mice with H22 ascitic tumor cells was established. Eighty-four model mice were randomly and equally divided into Coix stalk extract groups 1-5 (10, 8, 6, 4 and 2 g/kg), model control group and cyclophosphamide group. Mice were treated orally with Coix stalk alcohol extraction solution (10, 8, 6, 4 and 2 g/kg), cyclophosphamide 0.02 g/kg and normal saline once a day for 8 days for Coix stalk extract group, cyclophosphamide group and model control group. The mouse activity, the size and the appearance of time of abdominal swelling, and changes of hair, feeding and drinking water quantity were observed in groups of mice. The solid tumor mass was measured in H22 tumor-bearing mice. The tumor inhibitory rate, liver index, spleen index and thymus index were calculated. Results The axillary tumor muster was found first in model control group with the fastest growth, reduced independent activity, decreased appetite and dim in hair color, followed by the Coix stalk extract group 1 and group 2. The last was Coix stalk extract group 5 and cyclophosphamide group. The solid tumor mass were (0.47±0.18), (0.37± 0.13), (0.34±0.10), (0.30±0.11) and (0.28±0.09) mg for Coix stalk alcohol extract groups 1-5, which were significantly lower than those of model control group (0.60 mg±0.21 mg, F=5.700,P<0.05). The tumor inhibition rates were 21.67%, 38.33%, 43.33%, 50.00%, 53.33%and 60.00%in Coix stalk extract groups 1-5 and cyclophosphamide group. The liver index, spleen index and thymus index were lower in cyclophosphamide group and Coix stalk alcohol extract groups than those of model control group (except for the spleen index of Coix stalk extract group 1). The liver index was lower in Coix stalk ethanol extract groups than that of cyclophosphamide group. There were no significant differences in the spleen index, thymus index between Coix stalk ethanol extract groups and cyclophosphamide group. Conclusion Coix stalk alcohol extract has inhibitory effects on the tumor and liver damage in H22 mice.
RESUMEN
Objective To develop mycobacterial inducible expression vectors which permit to overexpress Mycobacterium tuberculosis (Mtb) immunodominant antigen, and to analyze its immunogenicity after purification by affinity chromatography. Methods The regulatory region of M. smegmatis (Ms) acet-amidase(pACE) was obtained by PCR amplification, and was used as promoter to construct the mycobacteri-al inducible expression vectors, pMF series. The coding gene of Mtb chimeric antigen Ag856A2 which is a recombinant Ag85A with 2 copies of ESAT-6 inserted in its Acc Ⅰ site and showed excellent immunogenicity in the animal experiments we described previously, was cloned into the pMF vector series, and was induced to express by the addition of acetamide. The recombinant protein expressed in the Ms was purified by the Ni~(2+)-NTA affinity chromatography, the resulted homologous recombinant antigen was added into the spleen cells separated from BCG vaccinated mice, and the immunogenicity was analyzed by the IFN-γ ELISPOT as-say. Results The mycobacterial inducible expression vectors, pMF series was constructed successfully, target antigen could be. induced to express in the Ms by the addition of 0.02% acetamide, and could be puri-fied by the Ni~(2+) -NTA affinity chromatography due to the addition of 6×His tag in the vector pMF406. Fur-thermore, the mycobactefial homologous antigen could induce more IFN-γ secretion than the heterogonous one. Conclusion The mycobacterial inducible expression system based on the regulatory region of Ms acet-amidase as promoter could permit the Mtb target antigen of interest overexpression and purification, and the immunogenicity of the homologous antigen from Ms is better than that of be expressed from E. coli, which may be more potential for immunological detection of tuberculosis.