Figure 1.
Chemical structure of pseudolaric acid B (C23H28O8, MW = 432.5).
Figure 2.
Inhibition of gastric tumor growth by pseudolaric acid B and mean body weight change of nude mice.
A: growth curve of SGC7901 cell xenografts B: growth curve of SGC7901/ADR cell xenografts C: relative body weight change of mice with SGC7901 cell xenografts D: relative body weight change of mice with SGC7901/ADR cell xenografts. SGC7901 cells and SGC7901/ADR cells (2.5×106/ml) were injected subcutaneously into the axillary areas of nude mice, and when evident tumors were observed, the mice received a daily dose of 25 mg/kg pseudolaric acid B and/or 1.25 mg/kg adriamycin or normal saline (control)/tween solution (control) (n = 5 per group). Tumor volumes were monitored at different time points (Day1, 3, 5, 7, 9, 11, 13, 15, 17, 19). The IR of tumor growth in the drug-treated groups were compared with that in the control groups at the end of the experiment by one-way ANOVA. *p<0.05 vs control group.
Figure 3.
Subcutaneous xenografts of nude mice in different treatment groups.
A: isolated tumors of SGC7901 cells (above) and SGC7901/ADR cells (below) B: subcutaneous xenografts of SGC7901 cell line in nude mice C: subcutaneous xenografts of SGC7901/ADR cell line in nude mice. (group 1): NS control group (group 2): TWEEN control group (group 3): ADR group (group 4): PAB group (group 5): PAB+ADR group.
Table 1.
Antitumor effects of PAB and/or ADR on nude mice xenografts of SGC7901 cells and SGC7901/ADR cells.
Figure 4.
Cox-2, PKC-α, and P-gp expression levels of xenografts in different groups (×400).
A: expression of Cox-2 in mice xenografts B: expression of PKC-α in mice xenografts C: expression of P-gp in mice xenografts D: negative control E: xenograft by HE F: normal gastric tissue by HE. Tissues were fixed, embedded, mounted and stained by the SP method or HE staining using standard procedures. Scale bar, 25 µm.
Table 2.
Average optical density of Cox-2, PKC-α and P-gp in different treatment groups (mean ± SD).
Figure 5.
Inhibitory effects of PAB on expressions of Cox-2, PKC-α and P-gp in tumor tissues.
A: representative immunoblots of Cox-2, PKC-α, P-gp compared with β-actin in different treatment groups. (lane 1): NS control group (SGC7901/ADR) (lane 2): TWEEN control group (SGC7901/ADR) (lane 3): ADR group (SGC7901/ADR) (lane 4): PAB group (SGC7901/ADR) (lane 5): PAB+ADR group (SGC7901/ADR) (lane 6): NS control group (SGC7901). B: relative expression levels of Cox-2 (B1), PKC-α (B2), and P-gp (B3) in different treatment groups. The tumors were isolated and homogenized to measure the protein level, and β-actin was used as an internal control. Each immunoblot was representative of three distinct experiments with similar results. *p<0.05 vs control group.