Figure 4.

Changes in aromatase (CYP19) expression in H295R cells exposed to standardized extract of Ginkgo biloba (EGb761). (A) The polymerase chain reaction (PCR) products obtained by reverse transcription-PCR [13] were identified by electrophoresis. β-actin was amplified as an internal control, and the size of the detected PCR products for aromatase CDS, Exon I.1, Exon I.3, Exon PII, and β-actin are 987, 113, 339, 113, and 287 bp, (B) 50 μg of cell lysates were loaded in each lane and analyzed by immunoblotting with aromatase antibody (expected size of the aromatase protein: 53 kDa), and (C) the aromatase activity was determined using a tritiated water-release assay. H295R cells seeded in 24-well plates were treated with various doses of EGb761 for 24 hours and measured by direct and indirect methods as described in the material and methods section. The results are expressed as the mean±standard deviation of three separate experiments for each group. Values are significantly different from the control: ^**p<0.01. CDS, coding region sequences.