The purpose of this study was to explore the effect and mechanism of Xihuang Pills on rats with precancerous lesions of the breast. Of 48 healthy female rats, 8 were randomly selected as blank group, and the other 40 were treated with 7,12-dimethylbenzanthracene(DMBA) combined with estrogen and progestin to establish a model of precancerous lesions of the breast. The successfully modeled rats were randomly divided into a model group, a tamoxifen group(1.8 mg·kg~(-1)·d~(-1)), a Xihuang Pills low-dose group(0.3 g·kg~(-1)·d~(-1)), a medium-dose group(0.6 g·kg~(-1)·d~(-1)) and a high-dose group(1.2 g·kg~(-1)·d~(-1)). After 30 days of admi-nistration, the histopathological changes of viscera and breast were observed by haematoxylin and eosin(HE) staining, and the visceral index was calculated. Enzyme linked immunosorbent assay(ELISA) was used to detect the contents of estradiol(E_2) and progesterone(P) in serum. The protein expressions of vascular endothelial growth factor(VEGF) and fibroblast growth factor 2(FGF2) were detected by immunohistochemistry. The protein expressions of VEGF, vascular endothelial growth factor receptor 2(VEGFR2), phosphorylated-vascular endothelial growth factor receptor 2(p-VEGFR2), B-cell lymphoma-2(Bcl-2), and Bcl-2 associated X protein(Bax) were detected by Western blot and the mRNA expressions of VEGF, FGF2, CXC-chemokine receptor 4(CXCR4), cysteine aspartic acid-specific protease(caspase-3), and stromal cell-derived factor 1(SDF-1) were detected by real-time polymerase chain reaction(RT-PCR). HE staining revealed that the model group had some liver and kidney damages and severe hyperplastic mammary tissue, while the Xihuang Pills high-dose group had mild hyperplasia. Compared with the model group, the Xihuang Pills groups had lo-wer ovarian coefficient(P<0.05 or P<0.01) and Xihuang Pills high-dose group had lower uterine coefficient(P<0.01). ELISA results showed that compared with the model group, expressions of E_2 and P in Xihuang Pills high-dose group were significantly decreased(P<0.05 or P<0.01). Immunohistochemistry, Western blot and RT-PCR indicated that compared with the conditions in the model group, the protein and mRNA expressions of VEGF and FGF2 in the Xihuang Pills groups were down-regulated(P<0.05 or P<0.01), and the protein expression of Bcl-2 was lowered(P<0.01); there was a decrease in the protein expressions of VEGFR2 and p-VEGFR2(P<0.01), a down-regulation in the mRNA expressions of CXCR4 and SDF-1(P<0.01), while an increase in the mRNA expression of caspase-3(P<0.01) in both Xihuang Pills medium-dose and high-dose groups; the protein expression of Bax in Xihuang Pills high-dose group was increased(P<0.01). The above results indicated that Xihuang Pills can effectively intervene in precance-rous lesions of the breast, and the mechanism may be related to the regulation of E_2 and P secretion as well as the inhibition of angiogenesis and chemokine receptor expression, thus controlling the occurrence of precancerous lesions of the breast in rats.
Rats ; Female ; Animals ; Rats, Sprague-Dawley ; bcl-2-Associated X Protein ; Vascular Endothelial Growth Factor A/metabolism* ; Caspase 3 ; Vascular Endothelial Growth Factor Receptor-2 ; Fibroblast Growth Factor 2 ; Proto-Oncogene Proteins c-bcl-2 ; 9,10-Dimethyl-1,2-benzanthracene/toxicity* ; Precancerous Conditions ; Hyperplasia ; Receptors, Chemokine ; RNA, Messenger

BACKGROUNDZengshengping (ZSP) tablets had inhibitory effects on oral precancerous lesions by reducing the incidence of oral cancer. However, the severe liver toxicity caused by systemic administration of ZSP limits the long-term use of this anti-cancer drug. The purpose of this study was to evaluate the tumor inhibitory effects due to the topical application of extracts from ZSP, a Chinese herbal drug, on 7, 12-dimethlbenz(a)anthracene (DMBA) induced oral tumors in hamsters. The study also investigated the anti-cancer mechanisms of the ZSP extracts on oral carcinogenesis.

METHODSDMBA (0.5%) was applied topically to the buccal pouches of Syrian golden hamsters (6 - 8 weeks old) three times per week for six weeks in order to induce the development of oral tumors. Different fractions of ZSP were either applied topically to the oral tumor lesions or fed orally at varying dosages to animals with oral tumors for 18 weeks. Tumor volume was measured by histopathological examination. Tumor cell proliferation was evaluated by counting BrdU labeled cells and by Western blotting for mitogen-activated protein kinase (MAPK) protein levels. The protein levels of apoptosis marker Caspase-3 and regulator Bcl-2 protein were also measured by Western blotting.

RESULTSTopical application of DMBA to the left pouch of hamsters induced oral tumor formation. Animals treated with DMBA showed a loss in body weight while animals treated with ZSP maintained normal body weights. Both the ZSP n-butanol fraction and water fraction significantly reduced tumor volume by 32.6% (P < 0.01) and 22.9% (P < 0.01) respectively. Topical application of ZSP also markedly decreased the BrdU-positive cell numbers in oral tumor lesions and reduced the expression level of MAPK. In addition, ZSP promoted tumor cell apoptosis by increasing Caspase-3 expression but decreasing Bcl-2 protein production.

CONCLUSIONThe n-butanol and water fractions of ZSP are effective at inhibiting tumor cell proliferation and stimulating apoptosis in oral cancer suggesting that these fractions have chemopreventive effects on DMBA induced oral carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene ; toxicity ; Animals ; Antineoplastic Agents ; therapeutic use ; Cell Transformation, Neoplastic ; drug effects ; Cricetinae ; Drugs, Chinese Herbal ; therapeutic use ; Male ; Mesocricetus ; Mouth Neoplasms ; chemically induced ; drug therapy ; prevention & control

OBJECTIVECalcium Glucarate (Cag), Ca salt of D-glucaric acid is a naturally occurring non-toxic compound present in fruits, vegetables and seeds of some plants, and suppress tumor growth in different models. Due to lack of knowledge about its mode of action its uses are limited in cancer chemotherapy thus the objective of the study was to study the mechanism of action of Cag on mouse skin tumorigenesis.

METHODSWe have estimated effect of Cag on DMBA induced mouse skin tumor development following complete carcinogenesis protocol. We measured, epidermal transglutaminase activity (TG), a marker of cell differentiation after DMBA and/or Cag treatment and [3H] thymidine incorporation into DNA as a marker for cell proliferation.

RESULTSTopical application of Cag suppressed the DMBA induced mouse skin tumor development. Topical application of Cag significantly modifies the critical events of proliferation and differentiation TG activity was found to be reduced after DMBA treatment. Reduction of the TG activity was dependent on the dose of DMBA and duration of DMBA exposure. Topical application of Cag significantly alleviated DMBA induced inhibition of TG. DMBA also caused stimulation of DNA synthesis in epidermis, which was inhibited by Cag.

CONCLUSIONCag inhibits DMBA induced mouse skin tumor development. Since stimulation of DNA synthesis reflects proliferation and induction of TG represents differentiation, the antitumorigenic effect of Cag is considered to be possibly due to stimulation of differentiation and suppression of proliferation.

9,10-Dimethyl-1,2-benzanthracene ; toxicity ; Administration, Topical ; Animals ; Anticarcinogenic Agents ; therapeutic use ; Carcinogens ; toxicity ; Cell Division ; drug effects ; DNA ; biosynthesis ; Enzyme Inhibitors ; toxicity ; Female ; Glucaric Acid ; therapeutic use ; Mice ; Skin Neoplasms ; chemically induced ; enzymology ; prevention & control ; Thymidine ; metabolism ; Transglutaminases ; metabolism

OBJECTIVETo study the immunotoxicity induced by 9,10-dimethyl-1,2-benzathrancene (DMBA) in metallothionein gene-knocked-out mice [MT(-/-)] as compared with that in wild-type mice [(MT(+/+)].

METHODSFemale mice were treated with 25 mg/kg and 50 mg/kg of DMBA i.p., respectively and immunized with sheep red blood cells (SRBC) i.v. on the following day and rechallenged by injection of SRBC via footpad s.c. on the fourth day post-immunization. Humoral and cell-mediated immune function was assessed by the number of spleen IgM antibody plaque formation cells (PFC) to SRBC and cell-mediated delayed-type hypersensitivity (DTH) measured by footpad swelling thickness.

RESULTSAfter treatment with 25 mg/kg DMBA, a decrease in weight of their spleen and thymus and PFC/spleen were observed in MT(-/-) mice, while only decrease in thymus weight of MT(+/+) mice. The humoral function was suppressed by 72% in MT(-/-) mice. No obvious change in cell-mediated immune function was observed both in MT(-/-) and MT(+/+) mice. Both humoral and cell-mediated immune function were suppressed more severe (91%) in MT(-/-) mice treated with 50 mg/kg DMBA than those treated with 25 mg/kg DMBA (72%). DTH was not altered by DMBA in MT(+/+) mice. The weight of their spleen and thymus decreased and humoral immune function suppressed in MT(+/+) mice, but these changes were significantly less severe. No obvious suppression of cell-mediated immune function was observed in MT(+/+) mice.

CONCLUSIONTheir humoral and cell-mediated immune function was more susceptible to being suppressed by DMBA in MT(-/-) mice, indicating that MT could protect their immune function from damage caused by DMBA.

9,10-Dimethyl-1,2-benzanthracene ; toxicity ; Animals ; Immunity ; drug effects ; Metallothionein ; physiology ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Organ Size ; drug effects