Objective To investigate whether recombinant human endostatin can create a time window of vascular normalization prior to vascular pruning to alleviate hypoxia in Lewis lung carcinoma in mice. Methods Kinetic changes in morphology of tumor vasculature in response to recombinant human endostatin were detected under a confocal microscope with immunofluorescent staining in Lewis lung carcinomas in mice. The hypoxic cell fraction of different time was assessed with immunohistochemical staining . Effects on tumor growth were monitored as indicated in the growth curve of tumors . Results Compared with the control group vascularity of the tumors was reduced over time by recombinant human endostatin treatment and significantly regressed for 9 days. During the treatment, pericyte coverage increased at day 3, increased markedly at day 5, and fell again at day 7. The vascular basement membrane was thin and closely associated with endothelial cells after recombinant human endostatin treatment, but appeared thickened, loosely associated with endothelial cells in control tumors. The decrease in hypoxic cell fraction at day 5 after treatment was also found. Tumor growth was not accelerated 5 days after recombinant human endostatin treatment. Conclusions Recombinant human endostatin can normalize tumor vasculature within day 3 to 7, leading to improved tumor oxygenation. The results provide important experimental basis for combining recombinant human endostatin with radiation therapy in human tumors.

OBJECTIVE: To establish a high-performance liquid chromatographic method (HPLC) for the simultaneous determination of 16 compounds from Artemisia ordosica. METHODS: HPLC was used to analyze 16 quality indicators of A. ordosica. The HPLC conditions were as follows: Agilent Eclipse Plus C₁₈ column (250 mm × 4.6 mm, 5 μm) with acetonitrile (A)-water (B) as mobile phase, gradient elution: 0-10 min, 75%-65% B; 10-30 min, 65%-35% B; and finally 30-40 min, 35%-15% B. The flow rate was 1.0 mL/min, the column temperature was 40 °C, the injection volume was 10 μL, and monitored by absorbance at 285 nm for compounds 1- 10, 12 and 225 nm for compounds 11, 13- 16. RESULTS: Under the selected experimental chromatographic conditions, compounds 1- 16 showed good linearity (r > 0.9993) in a wide concentration range. Their average recoveries were 99.50%, 95.38%, 97.75%, 96.00%, 98.20%, 97.50%, 95.50%, 99.33%, 96.75%, 96.50%, 98.50%, 97.83%, 99.20%, 95.33%, 97.33% and 96.30%, respectively, and the RSD were 1.99%, 1.81%, 1.63%, 1.98%, 1.67%, 1.92%, 1.74%, 1.67%, 1.90%, 1.72%, 1.88%, 1.83%, 1.79%, 1.76%, 1.81% and 1.96%, respectively. CONCLUSION Based on the results of the HPLC analysis, it was concluded that p-hydroxycinnamic acid ( 1), O-hydroxycinnamic acid ( 2), coniferyl alcohol ( 5), 5,4'-dihydroxy-7,3'-dimethoxyflavanone ( 8), 5,4'-dihydroxy-7-methoxyflavanone ( 9), 5-hydroxy-7,4'-dimethoxyflavanone ( 12), dehydrofalcarindiol ( 13), arteordoyn A ( 14), dehydrofalcarinol ( 15) and capillarin ( 16) are best suited for the role of quality indicators of A. ordosica grown in different ecological environments.