The mutant K159A, which is partially active in vitro, did not show detectable activity in vivo, indicating that the three active site mutants, K159A, S235A, and S259A, can be used as inactive controls in an in vivo experiment.
It is notable, however, that compounds 4ll (R = OH) and 4mm (R = 3-thiophenyl) were devoid of cytoprotective activity and were therefore used as inactive controls in further experiments.
The peptide inhibitor AcF- OpdChaWR) AcF- OpdChaWRs inastive control peptide AcdChaPwell-NH2 were synthesized by Biosyntas GmbH (Berlits Germany) and inactive daily intraperitoneally at a controlration of 10 μmol/L starting at day 4 after ligation.
A second important issue is the use of Nec-1i, a demethylated variant of Nec-1, as an inactive control.
When Intralipid® was used as a control in propofol trials (to maintain blinding due to its milky-white colour), it was considered as an inactive control.
It is often used as an inactive control in studies using Nec-1 to exclude nonspecific off-target effects inherent to inhibitors.
In Ferri et al. ([25], p. 44), comparisons with TAU is said to yield relative effects whereas the Cochrane Handbook ([7], section 5.3) treats TAU (standard care) as an inactive control.
Along the same line, in vivo, high doses of Nec-1, Nec-1i and Nec-1s prevented tumor necrosis factor (TNF -induced morTNF -inducedly well, excluding the use of Nec-1i as an inactive control.
