The rosemary plant, Rosmarinus officinalis L., one of the main members of the Lamiaceae family, is currently one of the most promising herbal medicines due to its pharmaceutical properties. This research aimed to evaluate the antioxidant role of Rosmarinus officinalis and its bioactive compounds on the skin, with a focus on the newly emerging molecular mechanisms involved, providing extensive scientific evidence of its anti-inflammatory, antimicrobial, wound-healing and anticancer activity in dermatological practice. The search was conducted on articles concerning in vitro and in vivo studies in both animals and humans. The results obtained confirm the antioxidant role of R. officinalis. This assumption derives the possibility of using R. officinalis or its bioactive elements for the treatment of inflammatory and infectious skin pathologies. However, although the use of rosemary in the treatment of skin diseases represents a fascinating line of research, future perspectives still require large and controlled clinical trials in order to definitively elucidate the real impact of this plant and its components in clinical practice.

Lipid peroxidation (LPO) is a biochemical process through which lipids are subjected to a peroxidation reaction in the presence of free radicals. The process can cause alterations in biological membranes and the formation of substances harmful to the body that can form aggregates with proteins and nucleic acids. Malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) are the main products of LPO. These compounds have cytotoxic and genotoxic properties and contribute to the pathogenesis of various diseases. This research focuses on the correlation between LPO and skin diseases. For some skin diseases, such as psoriasis, vitiligo, and alopecia, LPO products have been shown to have a clear role in the pathogenesis of the disease. Lipid aldehydic products like MDA and 4-HNE can enhance inflammation by stimulating pro-inflammatory genes and producing cytokines. Furthermore, these products can stimulate cell death and increase oxidative stress. For other diseases (atopic dermatitis, urticaria, pemphigus, and melanoma), the role of LPO is unclear, even if the levels of LPO biomarkers are elevated in proportion to the severity of the disease. LPO can also be exploited to counteract the proliferation of neoplastic cells. Therefore, enhancing LPO would play an adjuvant role in the therapy of neoplastic diseases such as melanoma. In particular, the therapeutic implication resulting from the role of LPO products in the cytotoxicity induced by photodynamic therapy used for the adjuvant treatment of melanoma could be of interest in the future.

Atopic dermatitis is a chronic inflammatory skin disease in which the overproduction of reactive oxygen species plays a pivotal role in the pathogenesis and persistence of inflammatory lesions. Phototherapy represents one of the most used therapeutic options, with benefits in the clinical picture. Studies have demonstrated the immunomodulatory effect of phototherapy and its role in reducing molecule hallmarks of oxidative stress. In this review, we report the data present in literature dealing with the main signaling molecular pathways involved in oxidative stress after phototherapy to target atopic dermatitis-affected cells. Since oxidative stress plays a pivotal role in the pathogenesis of atopic dermatitis and its flare-up, new research lines could be opened to study new drugs that act on this mechanism, perhaps in concert with phototherapy.

Psoriasis is a chronic immune-mediated skin and joint disease, with a plethora of comorbidities, characterized by a certain genetic predisposition, and a complex pathogenesis based on the IL-23/IL-17 pathway. There is no doubt that the patients affected by psoriasis are more susceptible to infections as well as that the risk of infection is higher in psoriatic subjects than in the general population. The advent of biotechnological agents on the therapeutic arsenal actually available for the treatment of moderate-to-severe patients, given the fact that the severity of the disease is a predictor of the level of infectious risk, has raised the question of whether these ‘new’ drugs could be considered a safer option and how they can be used in selected cases. Old and newer strategies in cases of chronic infectious conditions are reviewed under the light of clinical trials and other studies present in literature.

Interleukin 31 belongs to the IL-6 superfamily, and it is an itch mediator already studied in several diseases, comprising atopic dermatitis, allergic pathologies, and onco-hematological conditions. This research aims to assess the role of this cytokine in the pathogenesis of these conditions and its potential therapeutic role. The research has been conducted on articles, excluding reviews and meta-analysis, both on animals and humans. The results showed that IL-31 plays a crucial role in the pathogenesis of systemic skin manifestations, prognosis, and itch severity. Traditional therapies target this interleukin indirectly, but monoclonal antibodies (Mab) directed against it have shown efficacy and safety profiles comparable with biological drugs that are already available. Future perspectives could include the development of new antibodies against IL-31 both for humans and animals, thus adding a new approach to the therapy, which often has proven to be prolonged and specific for each patient.

High-mobility Group Box 1 (HMGB1) is a nuclear protein that plays a key role in acute and chronic inflammation. It has already been studied in several diseases, among them melanoma. Indeed, HMGB1 is closely associated with cell survival and proliferation and may be directly involved in tumor cell metastasis development thanks to its ability to promote cell migration. This research aims to assess the role of this molecule in the pathogenesis of human melanoma and its potential therapeutic role. The research has been conducted on the PubMed database, and the resulting articles are sorted by year of publication, showing an increasing interest in the last five years. The results showed that HMGB1 plays a crucial role in the pathogenesis of skin cancer, prognosis, and therapeutical response to therapy. Traditional therapies target this molecule indirectly, but future perspectives could include the development of new target therapy against HMGB1, thus adding a new approach to the therapy, which has often shown primary and secondary resistance. This could add a new therapy arm which has to be prolonged and specific for each patient.