Chemopreventive effect of modified zengshengping on oral cancer in a hamster model and assessment of its effect on liver.

Ethnopharmacological relevance Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumors, seriously compromising patients' quality of life. Previous studies showed that Zengshengping (ZSP), a popular traditional Chinese medicine, has certain inhibiting effects on both oral precancerous lesions and OSCC. However, few reports underlined ZSP side effects such as liver toxicity, which limit its long-term application. Aim of the study was to evaluate the chemopreventive effect of a modified ZSPs formula on oral cancer in a hamster model. Its effect on hamster liver was also assessed. Materials and Methods The original medicine (ZSP-1) and other two formulas slightly different and called ZSP-2 and ZSP-3 were prepared ahead of time. DMBA (0.5%) was topically applied for 6 weeks to induce a premalignant lesion on hamsters' cheek pouch, then ZSP-1/2/3 were intragastrically administered for 8 weeks. Hamster treated with DMBA + each of the ZSPs represented the ZSP-1/2/3 groups, while those without ZSP-1/2/3 treatment represented the DMBA group. To assess the effect of ZSPs in the liver, intragastric administration of ZSP-1/2/3 was carried out to other groups of hamsters for 12 weeks and the blood was collected every two weeks to detect the hepatic function. Some of the hamsters were sacrificed at the end of 12 weeks, while the remaining animals were sacrificed after other 4 weeks to estimate the effect of ZSP-1/2/3 withdrawal on the liver. Results showed that tumor development in the ZSP-1/2/3 groups was less than that in DMBA group. BrdU, CD31 and COX-2 expression in the hyperplastic tissues was significantly lower in the ZSP-1/2/3 groups than that in the DMBA group. In addition, VEGF and COX-2 expression in ZSP-1/2/3 groups was lower while caspase-9 and p53 expression was higher than those in the DMBA group. Finally, PTEN expression in ZSP-1/2/3 groups was higher than that in the DMBA group. As regard the effect in the liver, ALP in the ZSP-1/2/3 groups was higher than that in the control group treated with an intragastric administration of ddH2O. After 4 weeks of withdrawal, the hamsters of the ZSP-3 group did not recover from the increase in ALP. Histopathology showed the presence of inflammatory lesions in each group after 12 weeks, especially in the ZSP-1/3 groups, and the number of apoptotic cells in the ZSP-3 group was higher than that in the other groups, without any recovery after withdrawal of the drug. At 12 weeks, the MDA in the ZSP-1 group was higher than that in the control group and the ZSP-2 group, but the difference disappeared after drug withdrawal because the MDA in the ZSP-1/3 groups decreased. Conclusions ZSP-2 possessed a chemopreventive effect against oral cancer by inhibiting inflammation, proliferation of tumor cells, generation of microvessels and by promoting tumor cell apoptosis. In addition, hepatotoxicity of ZSP-2, which might be related to oxidative stress injury, was reduced to some extent.

Anti-tumor Effect of Rhaponticum uniflorum Ethyl Acetate Extract by Regulation of Peroxiredoxin1 and Epithelial-to-Mesenchymal Transition in Oral Cancer.

Objective: To explore whether Rhaponticum uniflorum (R. uniflorum) had anti-tumor effects in oral cancer and investigate the molecular mechanisms involved in these anti-tumor effects. Methods: Chemical compositions of R. uniflorum ethyl acetate (RUEA) extracts were detected by ultra-performance liquid chromatography-Q/time-of-flight mass spectrometry (UPLC-Q/TOF-MS), followed by pharmacology-based network prediction analysis. The effects of RUEA extracts on proliferation, apoptosis, migration, and invasion ability of human oral squamous cell carcinoma (OSCC) cell line SCC15 were evaluated by CCK8 assay, Annexin V- fluorescein isothiocyanate/propidium iodide staining, wound healing assay, and Matrigel invasion assay, respectively. The mRNA and protein expression of peroxiredoxin1 (Prx1), the epithelial-to-mesenchymal transition (EMT) marker E-cadherin, vimentin, and Snail were determined by quantitative real-time reverse transcription polymerase chain reaction and western blotting. A mouse xenograft model of SCC15 cells was established to further evaluate the effect of RUEA extracts in vivo. Immunohistochemical assessment of Ki67 and terminal deoxynucleotidyl transferase dUTP nick end labeling staining of apoptotic cells were performed on the tumor tissues to assess the effects of RUEA extracts on proliferation and apoptosis. Results: Fourteen compounds were identified from RUEA extracts by UPLC-Q/TOF-MS. The pharmacology-based network prediction analysis showed that Prx1 could be a potential binder of RUEA extracts. In SCC15 cells, RUEA extracts inhibited cell viability, induced apoptosis, and suppressed cell invasion and migration in a concentration-dependent manner. After treatment with RUEA extracts, the mRNA and protein expression of E-cadherin increased, whereas those of Prx1, vimentin, and Snail decreased. RUEA extracts also affected the EMT program and suppressed cell invasion and migration in Prx1 knockdown SCC15 cells. In an OSCC mouse xenograft model, RUEA extracts (25 and 250 mg/kg) significantly inhibited the growth of tumors. Compared with the control group, Ki67 expression was reduced and apoptosis rates were elevated in the transplanted tumors treated with RUEA extracts. RUEA extracts increased the expression of E-cadherin and decreased the expression of Prx1, vimentin, and Snail in vivo. Conclusion: RUEA extracts inhibited tumor growth and invasion by reducing Prx1 expression and suppressing the EMT process in OSCC. RUEA extracts may be a potential candidate for OSCC treatment.

[Chemopreventive effect of boswellic acid and curcumin on 7,12-dimethyl benzanthracene-induced hamster cheek pouch carcinogenesis].

OBJECTIVE: To evaluate the chemopreventive effects of boswellic acid and curcumin on 7,12-dimethyl benzanthracene(DMBA)-induced oral carcinogenesis in the hamster cheek pouch model. METHODS: Male Syrian golden hamsters (6 - 8 weeks old, 80 - 130 g in weight) were randomly divided into seven groups, with group A serving as the untreated negative control. The left cheek pouch of the remaining hamsters was topically treated with 0.5% DMBA in mineral oil three times a week for 6 weeks. They were then randomized to six groups with group B serving as a positive control and receiving no further treatment. Groups C-G were treated topically with 5, 10 mg/L boswellic acid, 5, 10 µmol/L curcumin, or the combination of 5 mg/L boswellic acid and 5 µmol/L curcumin three times per week for 18 weeks. The animals were injected with bromodeoxyuridine intraperitoneally at 50 mg/kg 2 h prior to killing. At the 25 th week all the hamsters were sacrificed and cheek pouch tissue was harvested. One half of the tissue was snap frozen in liquid nitrogen for analysis of arachidonic acid metabolites, and the other half was fixed in 10% phosphate-buffered saline(PBS)-buffered formalin for histopathological examination. RESULTS: Six-weeks of DMBA followed by 18-weeks of topical application of boswellic acid and curcumin, both boswellic acid (5, 10 mg/L) and curcumin (5, 10 µmol/L) significantly inhibited the incidence from 93.8% to 73.9% (P > 0.05), numbers from 2.19 ± 0.98 to 1.13 ± 0.81 (P < 0.01) and size of visible tumors. Microscopically the incidence of squamous cell carcinoma and BrdU index were also significantly suppressed by boswellic acid and curcumin. CONCLUSIONS: Both boswellic acid and curcumin were effective in preventing oral carcinogenesis in DMBA-induced hamster cheek pouch model.