PMID:27188280Д¬omputational Model of Steroidogenesis in Human H 295 R Cells to Predict Biochemical Response to Endocrine Active Chemicals: Model Development for MetyraponeД«ACKGROUND: An in vitro steroidogenesis assay using the human adrenocortical carcinoma cells H 295 R is being evaluated as a possible toxicity screening approach to detect and assess the impact of endocrine active chemicals (EAC) capable of altering steroid biosynthesis. The present study provides good information on potential therapeutic effects of EGb761 on estrogen dependent breast cancer. Conclusions These results suggest that EGb761 could regulate steroidogenesis-related genes such as CYP19 and 17ГЋВІ-HSD1, and lead to a decrease in 17ГЋВІ-estradiol and testosterone. The coding sequence/ Exon PII of CYP19 gene transcript and protein level of CYP19 were significantly decreased by EGb761. EGb761 treatment of H 295 R cells resulted in a significant decrease of aromatase activity as measured by the direct and indirect assays. Genes (CYP19 and 17ГЋВІ-HSD1) related to the estrogen steroidogenesis were significantly decreased by EGb761. Results H 295 R cells exposed to EGb761 (10 and 100 ГЋВјg/mL) showed a significant decrease in 17ГЋВІ-estradiol and testosterone, but no change in aldosterone or cortisol. Finally, aromatase activities were measured with a tritiated water-release assay and by western blotting analysis. Real-time polymerase chain reaction were performed to evaluate effects on critical genes in steroid hormone production, specifically cytochrome P450 (CYP11/ 17/19/21) and the hydroxysteroid dehydrogenases (3ГЋВІ-HSD2 and 17ГЋВІ-HSD1/4). Methods Cortisol, aldosterone, testosterone, and 17ГЋВІ-estradiol were evaluated in the H 295 R cells by competitive enzyme-linked immunospecific assay after exposure to EGb761. Therefore, the effects of EGb761 on steroidogenesis and aromatase activity was studied using a H 295 R cell model, which was a good in vitro model to predict effects on human adrenal steroidogenesis. Although it is known that standardized extract of Ginkgo biloba (EGb761) induces anti-carcinogenic effects like the aromatase inhibitors, the effects of EGb761 on steroidogenesis have not been studied yet. Objectives Aromatase inhibitors that block estrogen synthesis are a proven first-line hormonal therapy for postmenopausal breast cancer. The effects of the standardized extracts of Ginkgo biloba on steroidogenesis pathways and aromatase activity in H 295 R human adrenocortical carcinoma cells A high-throughput assay using H 295 R human adrenocortical carcinoma cells was used to evaluate the effect of 2,060 chemical samples. High-throughput screening of chemical effects on steroidogenesis using H 295 R human adrenocortical carcinoma cellsДisruption of steroidogenesis by environmental chemicals can result in altered hormone levels causing adverse reproductive and developmental effects.

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