Anti-inflammatory effect of Arnica montana in a UVB radiation-induced skin-burn model in mice

Current Knowledge on Interactions of Plant Materials Traditionally Used in Skin Diseases in Poland and Ukraine with Human Skin Microbiota

Skin disorders of different etiology, such as dermatitis, atopic dermatitis, eczema, psoriasis, wounds, burns, and others, are widely spread in the population. In severe cases, they require the topical application of drugs, such as antibiotics, steroids, and calcineurin inhibitors. With milder symptoms, which do not require acute pharmacological interventions, medications, dietary supplements, and cosmetic products of plant material origin are gaining greater popularity among professionals and patients. They are applied in various pharmaceutical forms, such as raw infusions, tinctures, creams, and ointments. Although plant-based formulations have been used by humankind since ancient times, it is often unclear what the mechanisms of the observed beneficial effects are. Recent advances in the contribution of the skin microbiota in maintaining skin homeostasis can shed new light on understanding the activity of topically applied plant-based products. Although the influence of various plants on skin-related ailments are well documented in vivo and in vitro, little is known about the interaction with the network of the skin microbial ecosystem. The review aims to summarize the hitherto scientific data on plant-based topical preparations used in Poland and Ukraine and indicate future directions of the studies respecting recent developments in understanding the etiology of skin diseases. The current knowledge on investigations of interactions of plant materials/extracts with skin microbiome was reviewed for the first time.

Pharmacological and Therapeutic Potential of Myristicin: A Literature Review

Natural products have been used by humanity for many centuries to treat various illnesses and with the advancement of technology, it became possible to isolate the substances responsible for the beneficial effects of these products, as well as to understand their mechanisms. In this context, myristicin, a substance of natural origin, has shown several promising activities in a large number of in vitro and in vivo studies carried out. This molecule is found in plants such as nutmeg, parsley, carrots, peppers, and several species endemic to the Asian continent. The purpose of this review article is to discuss data published in the last 10 years at Pubmed, Lilacs and Scielo databases, reporting beneficial effects, toxicity and promising data of myristicin for its future use in medicine. From 94 articles found in the literature, 68 were included. Exclusion criteria took into account articles whose tested extracts did not have myristicin as one of the major compounds.

MiR-4497 mediates oxidative stress and inflammatory injury in keratinocytes induced by ultraviolet B radiation through regulating NF-κB expression

BACKGROUND

To investigate the role and underlying mechanism of miR-4497 in oxidative stress and inflammatory injury in keratinocytes induced by ultraviolet B (UVB) radiation.

METHODS

An injury model of keratinocytes induced by UVB radiation was constructed. RT-qPCR, MTT assay and flow cytometry were adopted to detect miR-4497 expression in HaCaT cells, cell proliferation, and cell apoptosis, respectively. The levels of cytokines TNF-α, IL-18, IL-6 and IL-1β in cell culture supernatant were tested by ELISA. ROS levels in the cells were labeled by DCFH-DA fluorescent probe, and then quantitative fluorescence analysis was performed by flow cytometry. SOD activity in the cells was measured by xanthine oxidase assay kit. Western blot was used to determine NF-κB expression in cytoplasm and nucleus, and p-IκBα expression in the cells.

RESULTS

UVB radiation significantly increased miR-4497 expression in HaCaT cells, inhibited cell proliferation, and promoted cell apoptosis. Meanwhile, UVB radiation caused the promotion of secretion of cytokines TNF-α, IL-18, IL-6 and IL-1β. The production of reactive oxygen species (ROS) was promoted by UVB radiation, while SOD activity was inhibited. Nuclear transfer of NF-κB signal was also induced by UVB radiation. In addition, downregulation of miR-4497 expression significantly inhibited the effects of UVB radiation on cell proliferation, apoptosis, cytokine secretion, redox level and NF-κB signal in HaCaT cells, while overexpression of miR-4497 further enhanced these effects of UVB radiation on HaCaT cells.

CONCLUSIONS

UVB may promote the expression of inflammatory and oxidative stress signals in keratinocytes by upregulating miR-4497 expression, thus mediating cell injury.