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Updated: Apr 15, 2026
Quantification of Hypopigmentation Activity In Vitro
Published on: March 6, 2019
Expression of iNOS and NF-κB in melasma: an immunohistochemical study
Objective:
To investigate the role of inducible nitric oxide synthases (iNOS) and nuclear factor-kappa B (NF-κB) in the pathogenesis of melasma through their immunohistochemical (IHC) co-localization in skin of melasma and to correlate their expression with the clinical and the histopathological data.
Study Design:
This prospective case-control study was conducted on 34 female patients with melasma and 30 age- and gender-matched healthy subjects as a control group for evaluation of IHC expression of iNOS and NF-κB in melasma.
Results:
There were significant differences between lesional and perilesional skin regarding iNOS intensity, iNOS histo-score (H-score), NF-κB intensity, and NF-κB H-score (p < 0.001 for all). There were significant associations between the higher values of H-scores for both iNOS and NF-κB and positive family history (p = 0.002 and p = 0.001, respectively) and very severe melasma areas and severity index score (p < 0.001 and p = 0.001, respectively). There was a positive correlation between H-score values of both iNOS and NF-κB (r = +0.604 and p < 0.001).
Conclusion:
The IHC co-localization and direct correlation of both iNOS and NF-κB in melasma could provide evidence about their role as co-players in melanogenesis and might provide new targets for a more efficient treatment for melasma.
