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

Abstract

BackgroundGinkgo 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.MethodsAnimals 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.ResultsOverall, 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.ConclusionsCo-treatment with 100 mg/kg GbE presented a slightly beneficial effect on the therapeutic efficacy of TAM in female SD rats bearing mammary tumors.

Is there any potential anticancer effect of raloxifene and fluoxetine on DMBA‐induced rat breast cancer?

“…The cytochemical carcinogen, DMBA is a widely used agent for inducing breast carcinoma in experimental models and it effects either by initiating or promoting mutations in carcinogenesis responsible genes . In a study conducted by Kabel et al, it was used 80 mg/kg DMBA to induce breast cancer and was observed the levels of selected antioxidant in DMBA group were lower compared with therapeutic groups …”

Biochemical differences between nano- and normal formulation of tamoxifen and other natural bioactive materials ameliorate breast cancer in experimental rats

“…The side influence of tamoxifen has been perceived via recent studies. Numerous clinical studies have focused on discovering complementary substances that can synergize and diminish the side influences of tamoxifen (Yaacob et al 2014;Dias et al 2013). The beneficial relationship among tamoxifen and certain nutrients have been determined to reduce the medicinal side influences of tamoxifen amelioration or prevention (Tham et al 1998).…”

Chinese Medicines Improve Perimenopausal Symptoms Induced by Surgery, Chemoradiotherapy, or Endocrine Treatment for Breast Cancer

“…Recent studies have shown that GBE restrains estrogen-sensitive breast cancer by inhibiting aromatase and estrogen production (Park et al, 2015 , 2016 ), restrains the proliferation of ER-negative breast cancer cells independently of the ERs (Park et al, 2013 ; Zhao et al, 2013 ). Additionally, GBE has a synergistic effect with tamoxifen (Dias et al, 2013 ).…”