Anti-tumor effect of Liqi, a traditional Chinese medicine prescription, in tumor bearing mice.

BACKGROUND: Liqi, an herbal preparation used in traditional Chinese medicine, has been used to treat cancer in China for centuries. We investigated the anti-tumor effects of liqi and their mechanisms in mice that had been xenografted with tumors. METHODS: Sarcoma 180 tumor, Lewis lung carcinoma, and SGC-7901 cells were implanted in BALB/c mice, C57BL/6 mice, and BALB/c nude mice, respectively. Liqi was administered to subgroups of these mice. The tumor weight and size were measured. Cell cycle analysis and T lymphocyte subsets were determined by flow cytometry. The activity of NK cells and TNF was tested using cytotoxicity assay on YAC-1 cells and L929 cells, respectively, and the activity of IL-2 was tested with an IL-2-dependent CTLL-2 cell proliferation assay. Platelet aggregation was monitored by measuring electric impedance, and the levels of thromboxane A2 (TXA2) and prostacyclin (PGI2) in blood were measured by 125I-TXB2 and 125I-Keto-PGF1alpha radioimmunoassay. RESULTS: The results showed that liqi inhibited tumor growth in tumor-implanted mice and arrested the cell proliferation in the G0/G1 phase and reduced the portion of cells in S and G2/M phase for SGC-7901 cells. Liqi increased the activity of NK cells and TNF-alpha, stimulated IL-2 production and activity, and regulated T lymphocyte subpopulations. Liqi inhibited the Lewis lung carcinoma metastasis by inhibiting platelet aggregation and normalizing the balance between TXA2 and PGI2. CONCLUSION: All these findings demonstrated that liqi has an anti-tumor effect in vivo. The mechanism may be related to immune regulation and anticoagulation effects.

Antiaging effect of Cordyceps sinensis extract.

This experiment studied the effect of Cordyceps sinensis extract (CSE) on mice aged by d-galactose and castrated rats to analyse its antiaging effect. Water maze and step-down type avoidance tests were used to examine the effect of CSE on learning and memory. CSE shortened escape latency, prolonged step-down latency and decreased the number of errors in mice aged by d-galactose. The effect of CSE on the sexual function of castrated rats was evaluated by measuring the penis erection latency, mount latency and ejaculation latency. CSE appeared to shorten penis erection latency and mount latency in castrated rats. The study also measured the effect of CSE on the activity of age-related enzymes. The results showed that CSE improved the activity of superoxide dismutase, glutathione peroxidase and catalase and lowered the level of lipid peroxidation and monoamine oxidase activity in the aged mice. The study demonstrated that CSE can improve the brain function and antioxidative enzyme activity in mice with d-galactose-induced senescence and promote sexual function in castrated rats. All of these findings suggest that CSE has an antiaging effect.

Establishment of a cell-based assay to screen regulators of the hypoxia-inducible factor-1-dependent vascular endothelial growth factor promoter.

In this study, we established a drug screening system based on transcriptional regulation of vascular endothelial growth factor (VEGF) under hypoxia-inducible factor-1alpha control. We cloned the neomycin-resistance gene into the plasmid GL (pGL)3-promoter vector to generate the pGL3-promoter-neo vector. The 3 copies of the 47-bp fragment that contained the hypoxia response element of VEGF were synthesized and inserted in front of the minimal promoter of the pGL3-promoter-neo vector to generate p3HRE-luc-neo. The recombinant reporter gene vectors were transfected into EAhy926 cells, and stable cell lines were obtained. The positive cell line was selected for its ability to express luciferase in response to hypoxia. We demonstrated that CoCl(2) significantly enhances luciferase activity in a concentration-dependent fashion. We then optimized the cell density and incubation time under hypoxia which were used to screen. The assay exhibited a low background and was an ideal model for high-throughput screening for human VEGF regulators.