Effects of Ginkgo biloba on chemically-induced mammary tumors in rats receiving tamoxifen

• Autor(a) principal: Dias, Marcos Correa [UNESP]
• Data de Publicação: 2013
• Outros Autores: Furtado, Kelly Silva [UNESP], Rodrigues, Maria Aparecida Marchesan [UNESP], Barbisan, Luis Fernando [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1186/1472-6882-13-93; http://hdl.handle.net/11449/75272
• topic: Complementary and alternative medicine; Mammary carcinogenesis; Rat; Selective estrogen receptor modulator; Tamoxifen; caspase 3; estrogen receptor alpha; Ginkgo biloba extract; protein p63; tamoxifen; tamoxifen citrate; animal experiment; animal model; antineoplastic activity; apoptosis; breast tumor; cell proliferation; controlled study; female; Ginkgo biloba; nonhuman; protein cleavage; protein expression; rat; tumor volume; Animals; Antineoplastic Agents; Apoptosis; Breast Neoplasms; Cell Proliferation; Drug Therapy, Combination; Estrogen Receptor alpha; Female; Gene Expression Regulation, Neoplastic; Humans; Mammary Neoplasms, Animal; Plant Extracts; Rats; Rats, Sprague-Dawley

Background: Ginkgo biloba extract (GbE) is used extensively by breast cancer patients undergoing treatment with Tamoxifen (TAM). Thus, the present study investigated the effects of GbE in female Sprague-Dawley (SD) rats bearing chemically-induced mammary tumors and receiving TAM.Methods: Animals bearing mammary tumors (≥1 cm in diameter) were divided into four groups: TAM [10 mg/kg, intragastrically (i.g.)], TAM plus GbE [50 and 100 mg/kg, intraperitoneally (i.p.)] or an untreated control group. After 4 weeks, the therapeutic efficacy of the different treatments was evaluated by measuring the tumor volume (cm3) and the proportions of each tumor that were alive, necrotic or degenerative (mm2). In addition, labeling indexes (LI%) were calculated for cell proliferation (PCNA LI%) and apoptosis (cleaved caspase-3 LI%), expression of estrogen receptor-alpha (ER-α) and p63 biomarkers.Results: Overall, the tumor volume and the PCNA LI% within live tumor areas were reduced by 83% and 99%, respectively, in all TAM-treated groups when compared to the untreated control group. GbE treatment (100 mg/kg) reduced the proportions of live (24.8%) and necrotic areas (2.9%) (p = 0.046 and p = 0.038, respectively) and significantly increased the proportion of degenerative areas (72.9%) (p = 0.004) in mammary tumors when compared to the group treated only with TAM. The expression of ER-α, p63 and cleaved caspase-3 in live tumor tissues was not modified by GbE treatment.Conclusions: Co-treatment with 100 mg/kg GbE presented a slightly beneficial effect on the therapeutic efficacy of TAM in female SD rats bearing mammary tumors. © 2013 Dias et al.; licensee BioMed Central Ltd.