Determination of swainsonine in the endophytic Undifilum fungi by high-performance liquid chromatography with evaporative light-scattering detector.

Endophytic Undifilum oxytropis found within toxic locoweeds (Astragalus and Oxytropis spp.) produces the indolizidine alkaloid swainsonine, which is responsible for locoism in grazing animals. The aim of the current study is to establish an easy and accurate method for the determination of swainsonine in the endophytic Undifilum fungi. High-performance liquid chromatography (HPLC) with evaporative light-scattering detector (ELSD) was used for the assay of swainsonine in this study for the first time. The HPLC conditions were Waters XBridge hydrophilic interaction liquid chromatography column using acetonitrile-5 mM ammonium acetate (1:1, vol/vol) containing 0.02% (vol/vol) aqueous ammonium hydroxide as mobile phase at a flow rate of 0.5 mL/min. ELSD conditions were optimized at nebulizer-gas flow rate of 25 psi and drift tube temperature of 55 °C. The method was validated to achieve the satisfactory precision and recovery, and the calibration range was 15.625-250 µg/mL. Application of the developed analytical procedure to determine swainsonine content in the endophytic Undifilum fungi samples ensured its suitability for the routine analysis of swainsonine.

Antitumor activity of polysaccharides isolated from Patrinia heterophylla.

The research investigated the effect of Patrinia heterophylla Bunge (Valerianaceae) polysaccharides (PHB-P1) on U14-bearing mice. The tumor weight of mice treated with PHB-P1 (30, 60 mg/kg body weight) was significantly lower than that of the control group, a decrease of serum lactate dehydrogenase (LDH) activity was observed, and the serum alkaline phosphatase (AKP) level was increased slightly. The number of apoptotic tumor cells was significantly increased in the mice by treatment of PHB-P1 (30, 60 mg/kgbw). Cell cycle analysis showed the accumulation of tumor cells in the G2/M phase and a relative decrease of the S phase. By the immunohistochemical analysis, PHB-P1 (30, 60 mg/kgbw) might up-regulate the expression of p53 and Bax, and significantly inhibited the expression of Bcl-2 in tumor tissues. In conclusion, PHB-P1 could inhibit tumor growth and induce tumor cell apoptosis.

Anti-tumor activity of polysaccharides isolated from Patrinia scabra Bunge on U14 cervical carcinoma bearing mice.

The aim of our study was to investigate the effect of Patrinia scabra Bunge polysaccharide (PSB-P2) on cervical cancer cell (U14)-bearing mice. The tumor weight of mice treated with PSB-P2 (40, 80 mg/kg b.w.) was significantly lower than that of the control group and serum lactate dehydrogenase (LDH) activity was decreased, while serum alkaline phosphatase (AKP) level was only changed slightly. Meanwhile, the number of apoptotic tumor cells was significantly increased in the mice by the treatment of PSB-P2 (40, 80 mg/kg b.w.). At the same time, cell cycle analysis showed the accumulation of tumor cells in the G0/G1 phase and a relative decrease in the S phase. On the other hand, using the reverse transcription-polymerase chain reaction (RT-PCR) assay, PSB-P2 (40, 80 mg/kg b.w.) showed the up-regulation of p53 and Bax, and significant inhibition of Bcl-2 in tumor tissues. It suggests a possible mechanism of the inhibitory effect of PSB-P2 on tumor growth.

Biodegradation of Swainsonine by Acinetobacter calcoaceticus strain YLZZ-1 and its isolation and identification.

Eight swainsonine (SW)-degrading bacteria were isolated from the soil where locoweed was buried for 6 months and one of the strains (YLZZ-1) was selected for further study. Based on morphology, physiologic tests, 16S rRNA gene sequence, and phylogenetic characteristics, the strain showed the greatest similarity to members of the order Acinetobacters and within the order to members of the Acinetobacter calcoaceticus group. The ability of the strain for degrading SW, as sole carbon source, was investigated under different culture conditions. The preferential temperature and initial pH for the strain were 25-35 degrees C and 6-9, respectively. The optimal temperature for the strain was 30 degrees C and the optimal pH was 7.0. There was a positive correlation between degradation rate and inoculation amount. The concentration of SW affected the degradation ability. When the concentration of SW was lower than 100 mg/l, SW decreased immediately after incubation, and when the concentration of SW was 200 mg/l, there was an inhibiting effect for bacteria growth and SW degradation. The strain could degrade SW completely within 14 h when the concentration of SW was 50 mg/l. These results highlight the potential of this bacterium to be used in detoxifying of SW in livestock consuming locoweed.

[Effect of Gleditsia sinensis stings on growth inhibition and expression of PCNA and p53 in mice bearing uterine cervical carcinoma (U14)].

OBJECTIVE: To study the antitumor effect of the stings of Gleditsia sinensis on mice bearing uterine cervical carcinoma (U14) and the expression of PCNA (proliferating cell nuclear antigen) and p53. METHOD: The effect of the ethanolic extract of G. sinensis stings on the inhibition rate of solid tumor and the life span of ascites tumor were calculated by the animal tumor model experiment in vivo. The positive cell numbers of PCNA and mutant p53 protein were measured by immunohistochemical SP method. RESULT: As compared with the control group, the ethanolic extract of G. sinensis stings (250, 500 and 1 000 mg x kg(-1) body weight, p.o.) and CTX (25 mg kg(-1) body weight, i.p.) administration significantly reduced the tumor weight of solid tumor and increased the life span of ascites tumor harboring mice (P < 0.01). The inhibition rate of solid tumor and the rate in life span were up to 47.44%, 59.49%, 63.92%, 73.42% and 52.21%, 67.26%, 78.76%, 95.58% respectively. Meanwhile,the expression of PCNA and mutant p53 protein also suppressed by ethanolic extract (P < 0.05, P < 0.01). CONCLUSION: The stings of G. sinensis showed antitumor activity and its possible mechanism might be related with the expression inhibition of PCNA and mutant p53 protein.