e anti-proliferative and anti-invasive effects of the estrogen receptor modulator (Tamoxifen) and aromatase inhibitor (Letrozole) on T. gondii (RH strain) tachyzoites in vitro | ||||
Parasitologists United Journal | ||||
Article 6, Volume 15, Issue 3, December 2022, Page 266-273 PDF (629.88 K) | ||||
Document Type: Original Article | ||||
DOI: 10.21608/puj.2022.159135.1186 | ||||
View on SCiNiTO | ||||
Authors | ||||
Fatima Zahran ; Rasha Meselhey | ||||
Department of Medical Parasitology, Faculty of Medicine, Ain-Shams, Cairo, Egypt | ||||
Abstract | ||||
ackground: Tamoxifen is the first line of treatment in hormone receptor-positive breast cancer. Letrozole is developed for postmenopausal patients and metastatic breast cancer. Patients with concomitant chronic toxoplasmosis are at risk of reactivation of tissue cysts. It is still unknown whether these drugs will cause protection against reactivated toxoplasmosis or exacerbated symptoms. Objective: This study aimed to investigate the possible effect of Tamoxifen and Letrozole on T. gondii freed bradyzoites in case of rupture tissue cyst with their subsequent reactivation to tachyzoites. Material and Methods: The study was conducted using in vitro cultured T. gondii tachyzoites in a cultured Vero cell line. Different concentrations of Tamoxifen and Letrozole were used (0.24-125 ug/ml). Antiproliferative effect was determined by methyl thiazolyl tetrazolium (MTT) cytotoxicity assay estimated as cell line viability% reflecting the inhibition of tachyzoites proliferation after 24 and 48 h treatment. Antiinvasive effect was determined by counting Giemsa-stained intracellular tachyzoites inside infected Vero cells using light microscopy. Induced cytotoxic morphological changes in the tachyzoites was determined by transmission electron microscopy (TEM). Results: By MTT, cytotoxicity of both drugs to the infected cultured Vero cells indirectly assayed the decreased tachyzoites proliferation compared to the control drug-free parasites (P<0.01). Letrozole proved to be more cytotoxic than Tamoxifen after 48 h treatment (P<0.05). Both drugs decreased the ability of tachyzoites' invasion compared to drug-free tachyzoites (P<0.05) with no statistical difference between the used drugs. Additionally, TEM demonstrated tachyzoites damage caused by both drugs. Conclusion: Tamoxifen and Letrozole demonstrated anti-toxoplasmic activity, indicating that administering these drugs in cancer patients may also prevent the possibility of reactivated toxoplasmosis. In vivo studies are recommended to evaluate their efficacy. | ||||
Keywords | ||||
cancer breast; in vitro; letrozole; protective therapy; reactivated toxoplasmosis; tamoxifen; TEM | ||||
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