This is not the case; HSA and the other fluids tested as inductors were added to the growth medium (LB) medium, and the cells were allowed to grow in these conditions for 5 h at 37ºC. After that, the cells were collected, and RNA was extracted. Since HSA does not reach the cytosol, at least not in an intact manner, hydrolysis seems not possible during cell growth.
If we understand correctly, the reviewer’s argument, i.e., a reduction in RNA when the cells were cultured in the presence of HSA may be due to the HSA’s RNA-hydrolyzing activity, requires that HSA contacts the RNA that will be hydrolyzed.