Introduction: Vitiligo is a relatively common autoimmune depigmenting disorder of skin. There has been a great advance in understanding the pathological basis, which has led to development and utilisation of various new molecules in treating vitiligo. This review aims at a comprehensively describing the treatments available and the emerging treatment aspects and the scope for future developments. Areas covered: This study comprehensively summarises the current concepts in the pathogenesis of vitiligo with special focus on the cytokine and signalling pathways, which are the targets for newer drugs. JAK kinase signalling pathways and the cytokines involved are the focus of vitiligo treatment in current research, followed by antioxidant mechanisms and repigmenting mechanisms. Topical immunosuppressants may be an alternative to steroids in localised vitiligo. Newer repigmenting agents like basic fibroblast growth factors, afamelanotide have been included and a special emphasis is laid on the upcoming targeted immunotherapy. Expert opinion: The treatment of vitiligo needs to be multimodal with emphasis on targeting different limbs of the pathogenesis. Topical and oral JAK inhibitors are the most promising new class of drugs currently available for treating vitiligo and acts best in conjunction with NB-UVB.
Psoriasis, a multisystem chronic disease characterized by abnormal keratinocyte proliferation, has an unclear pathogenesis where systemic inflammation and oxidative stress play mutual roles. Dermal fibroblasts, which are known to provide a crucial microenvironment for epidermal keratinocyte function, represented the selected experimental model in our study which aimed to clarify the potential role of SIRT1 in the pathogenetic mechanisms of the disease. We firstly detected the presence of oxidative stress (lipid peroxidation and total antioxidant capacity), significantly reduced SIRT1 expression level and activity, mitochondrial damage and apoptosis (caspase-3, -8 and -9 activities) in psoriatic fibroblasts. Upon SIRT1 activation, redox balance was re-established, mitochondrial function was restored and apoptosis was no longer evident. Furthermore, we examined p38, ERK and JNK activation, which was strongly altered in psoriatic fibroblasts, in response to SIRT1 activation and we measured caspase-3 activity in the presence of specific MAPK inhibitors demonstrating the key role of the SIRT1 pathway against apoptotic cell death via MAPK modulation. Our results clearly demonstrate the involvement of SIRT1 in the protective mechanisms related to fibroblast injury in psoriasis. SIRT1 activation exerts an active role in restoring both mitochondrial function and redox balance via modulation of MAPK signaling. Hence, SIRT1 can be proposed as a specific tool for the treatment of psoriasis.