Natural products have long been used for skincare and dermo-cosmetic topical formulations. Of particular interest are the unique phytochemical and properties of marine-based extracts and compounds. Both Dunaliella salina and Haloferax volcanii have been shown to possess several health-promoting properties. However, the impact of the extracts on air-pollution-induced damage and wound healing had not been elucidated, as well as their compatibility and possible synergistic actions. Thus, HaCaT human keratinocytes cells were treated without or with increasing concentrations of Dunaliella salina extract, Haloferax volcanii extract, and a combination of both. Their ability to prevent induction of radical formation and skin inflammation by air pollution (diesel particulate matter, DPM) was monitored. In addition, their impact on wound closure and the scavenging capacity of the extracts were determined. DPM markedly enhanced cellular reactive oxygen species (ROS) formation and secretion of the inflammatory cytokine interleukin-8 (IL-8). Treatment with Haloferax volcanii extract reduced ROS in a dose-dependent manner, whereas Dunaliella salina had no significant effect. Importantly, the combination of both showed synergistic activity. Similar results were obtained in the quantification of IL-8 secretion. In the wound healing model, both extracts were ineffective as individual treatments, and their combination markedly enhanced wound closure. Finally, the acellular scavenging results correlate with the in vitro data, suggesting that the synergistic action is due to the antioxidant properties of the combinations. The results suggest that a combination of Dunaliella salina and Haloferax volcanii can be used as an effective skincare complex with several applications. Thorough phytochemical analysis should be performed in order to pinpoint the active medicinal compounds underlining these in vitro activities, as well as a clinical validation.

Skin cancer, including both melanoma and non-melanoma, is the most common type of malignancy, which causes substantial morbidities and mortalities. Although the significant increase in the understanding of skin cancer formation and the development of novel personalized drug regimens have occurred, new treatment options are always of need. The use of natural compounds to alleviate the symptoms or even to prevent and treat cancer has long been proposed. Specifically, the use of marine-based organisms as a source for cancer cure and remedy is being evaluated extensively. The objective of the current study was to assess the ability of the green microalgae Dunaliella salina, the Dead-Sea-derived Haloferax volcanii, and its combinations to treat skin cancer in vitro. The results demonstrate the Dunaliella and Haloferax can reduce sarcoma and basal cell carcinoma cellular growth. Importantly, their combination acts synergistically in a caspase-3 independent manner. Moreover, a synergistic action was found when evaluated sarcoma cell invasion rate, which was completely blocked at pharmacological relevant amounts of the compounds. Collectively, the results demonstrate that the combination of Haloferax volcanii and Dunaliella salina can be used as a new treatment for skin cancer. The specific mechanism of action and further in vivo validation studies are of need.

Medicinal plants have been traditionally used to address and treat a variety of pathologies including skin diseases. Six medicinal herbs, grown in Jordan, were evaluated for their ability to reduce UVB-induced skin damage, a major contributor to erythema, skin aging and cancer formation. Ethanolic, acetonic and aqueous extracts were prepared from the stems and leaves of the plants. Human keratinocyte HaCaT cells were incubated without or with the different extracts for 24 hr, exposed to UVB irradiation and taken for viability and apoptosis assessment by resazurin and caspase-3 determinations, respectively. Selected extracts were further evaluated by the DCFDA method (ROS production measurement) and on pig and human skin explants. From the 18 extracts screened, only Citrillus colocynthis extracts showed significant protective properties against UVB-induced apoptosis. UV protective activity was found in the water extracts of both stem and leaf preparations of the plant. UV protection was independent of ROS production. Importantly, Citrillus colocynthis extracts were also able to attenuate the photodamage in both ex vivo skin models used in this study. Therefore, the current preliminary screening indicates that Jordanian medicinal plants might be valuable sources for novel skin care compounds. This study also suggests that Citrillus colocynthis extracts exhibit significant photoprotection properties and may attenuate the deleterious effects of UVB radiation.