Beckman l7 65 ultracentrifuge

The liver tissues were homogenized in phosphate
buffer saline (PBS)
(40 mM), at pH 7.4 (Kinematica, Lucerne, Switzerland). Beckman L7-65
Ultracentrifuge (Beckman, Fullerton, USA) was used at 15,000g for 20 min, at 4 °C for separation of the supernatant.
Furthermore, the supernatants were subjected for Cu/Zn superoxide
dismutase (SOD) activity, malondialdehyde (MDA), and glutathione (GSH)
content. At 550 nm, the activity of Cu/Zn SOD was determined according
to established protocols,^{19 (link)} while GSH and
MDA content were determined according to the previously described
procedure.^{22 (link)} To extract out the proteinous
content, the supernatant was centrifuged for 15 min at 4000g with 1.0 M metaphosphoric acid (Rotina 420R, Andreas Hettich
GmbH, Tuttlingen, Germany). Finally, a solution of 700 μL of
nicotinamide adenine dinucleotide phosphate in PBS, deproteinized
sample, 25 μL water, 100 μL of DTNB were mixed to a volume
of 1.0 mL. Then, 10 μL of glutathione reductase was added to
the solution and was analyzed at 405 nm for 20 min. For determination
of glutathione in the samples, a series of dilution of glutathione
stock solution were compared to the standard curve.