Background:

(R)-(-)-Ibuprofen is the R enantiomer of Ibuprofen, inactive on COX, inhibits NF-κB activation; (R)-(-)-Ibuprofen exhibits anti-inflammatory and antinociceptive effects.

(R)-(-)-Ibuprofen is the R enantiomer of Ibuprofen, with no inhibitory effect on COX, but is involved in pathways of lipid metabolism and is incorporated into triglycerides along with endogenous fatty acids[1]. (R)-(-)-Ibuprofen (1 μM) significantly reduces NF-κB activation and completely prevents NF-κB induction at 10 μM. (R)-(-)-Ibuprofen inhibits NF-κB luciferase activity with an IC50 of 121.8 μM, weaker than that of S(+)-ibuprofen (IC50, 61.7 μM). Furthermore, (R)-(-)-Ibuprofen (10 mM) has no effect on HSF[2].

参考文献:
[1]. Evans AM, et al. Comparative pharmacology of S(+)-ibuprofen and (RS)-ibuprofen. Clin Rheumatol. 2001 Nov;20 Suppl 1:S9-14.
[2]. Scheuren N, et al. Modulation of transcription factor NF-kappaB by enantiomers of the nonsteroidal drug ibuprofen. Br J Pharmacol. 1998 Feb;123(4):645-52.