Abstract UVB-irradiation increases the risk of various skin disorders, therefore leading to inflammation and oxidative stress. In this sense, antioxidant-rich herbs such as Rosmarinus officinalis may be useful in minimizing the damage promoted by reactive oxygen species. In this work, we report the efficacy of a R. officinalis hydroethanolic extract (ROe)-loaded emulgel in preventing UVB-related skin damage. Total phenols were determined using Folin-Ciocalteu assay, and the main phytocomponents in the extract were identified by UHPLC-HRMS. Moreover, in vitro sun protection factor (SPF) value of ROe was also assessed, and we investigated the in vivo protective effect of an emulgel containing ROe against UVB-induced damage in an animal model. The ROe exhibited commercially viable SPF activity (7.56 ± 0.16) and remarkable polyphenolic content (24.15 ± 0.11 mg (Eq.GA)/g). HPLC-MS and UHPLC-HRMS results showcased that the main compounds in ROe were: rosmarinic acid, carnosic acid and carnosol. The evaluation of the in vitro antioxidant activity demonstrated a dose-dependent effect of ROe against several radicals and the capacity to reduce iron. Therefore, we demonstrated that topical application of the formulation containing ROe inhibited edema formation, myeloperoxidase activity, GSH depletion and maintained ferric reducing (FRAP) and ABTS scavenging abilities of the skin after UVB exposure.

Tephrosia toxicaria (Sw.) Pers., which is currently known as T. sinapou (Buc'hoz) A. Chev., Fabaceae, is a source of compounds such as flavonoids, however, few studies addressed the anti-inflammatory and antioxidant effects of T. sinapou. Therefore, we evaluated the antioxidant mechanisms of the T. sinapou ethyl acetate extract in vitro, and whether the extract affects leukocyte recruitment in four models of inflammation and the involvement of nitric oxide and cytokines in its mechanism. In vitro, it was observed that the extract presented hydrogen donating ability to 2,2-diphenyl-1-picryl-hydrazyl radical (DPPH<img src="/img/revistas/rbfar/2012nahead/aop23011img01.jpg" />), 2,2'-azino-di-(3-ethylbenzthiazoline-6-sulphonic acid) radical (ABTS+), and also efficiently inhibited iron-dependent and independent lipid peroxidation and iron chelation assays. In vivo, it inhibited the recruitment of total leukocytes and neutrophil induced by carrageenin, zymosan, glycogen and lipopolysaccharide in the peritoneal cavity of mice. Two mechanisms were detected: 1) T. sinapou effect on leukocyte recruitment depends on nitric oxide since was dose-dependently inhibited by treatment with L-NAME (nitric oxide synthase inhibitor), and 2) the extract also inhibited the production of crucial cytokines for the leukocyte recruitment; tumor necrosis factor α and interleukin-1β. Concluding, T. sinapou ethyl acetate extract reduces oxidative stress in vitro, and inflammatory leukocyte recruitment by a mechanism related to inhibition of cytokine production, and in a nitric oxide dependent manner in vivo.