Chemical Profile and Skin-Beneficial Activities of the Petal Extracts of Paeonia tenuifolia L. from Serbia.

Without being aware of its chemical makeup, many ancient societies have used Steppe peony in their traditional medicine. Given that modern phytopreparation intended for use on human skin requires, above all, knowledge of its chemical composition, the goal of this study was to make a screening of the composition of aqueous and methanolic extracts of the petals of P. tenuifolia L. and to examine them for various skin-beneficial properties. The extracts were prepared by maceration, ultrasound-assisted, and microwave-assisted extraction procedures. The chemical profiling was conducted by the use of UHPLC-LTQ-OrbiTrap MS and UHPLC/MS, and spectrophotometric methods for the determination of total polyphenol and total flavonoid contents. The biological activities entailed antioxidant ABTS, DPPH, CUPRAC (Cupric Ion Reducing Antioxidant Capacity), and FRAP (Ferric Reducing Antioxidant Power) assays, antimicrobial (antibacterial and antifungal) and antibiofilm activities, cytotoxicity, wound healing potential, as well as the adhesion and invasion of Staphylococcus lugdunensis. The results showed that the petals are rich in phenolic acids and flavonoids, which are commonly associated with numerous biological activities. The aqueous extracts were more efficient in the majority of the bioactivity assays then the methanolic ones, whereas the optimal extraction method varied between the assays. This study is the first step towards the safe use of the aqueous extracts of P. tenuifolia petals for therapeutic skin treatments.

DNA Demethylation Induces Tree Peony Flowering with a Low Deformity Rate Compared to Gibberellin by Inducing PsFT Expression under Forcing Culture Conditions.

Gibberellin (GA) is frequently used in tree peony forcing culture, but inappropriate application often causes flower deformity. Here, 5-azacytidine (5-azaC), an efficient DNA demethylating reagent, induced tree peony flowering with a low deformity rate by rapidly inducing PsFT expression, whereas GA treatment affected various flowering pathway genes with strong pleiotropy. The 5-azaC treatment, but not GA, significantly reduced the methylation level in the PsFT promoter with the demethylation of five CG contexts in a 369 bp CG-rich region, and eight light-responsive related cis-elements were also predicted in this region, accompanied by enhanced leaf photosynthetic efficiency. Through GO analysis, all methylation-closer differentially expressed genes (DEGs) were located in the thylakoid, the main site for photosynthesis, and were mainly involved in response to stimulus and single-organism process, whereas GA-closer DEGs had a wider distribution inside and outside of cells, associated with 12 categories of processes and regulations. We further mapped five candidate DEGs with potential flowering regulation, including three kinases (SnRK1, WAK2, and 5PTase7) and two bioactive enzymes (cytochrome P450 and SBH1). In summary, 5-azaC and GA may have individual roles in inducing tree peony flowering, and 5-azaC could be a preferable regulation approach; DNA demethylation is suggested to be more focused on flowering regulation with PsFT playing a core role through promoter demethylation. In addition, 5-azaC may partially undertake or replace the light-signal function, combined with other factors, such as SnRK1, in regulating flowering. This work provides new ideas for improving tree peony forcing culture technology.

Cigarette smoking and medical students.

Despite its well known harmful effects on health, tobacco use is widespread throughout the world. Approximately one third of the global population become smokers at the age of 15 years or more. The prevalence of smoking between genders is lessening. Earlier, men used to smoke three to four times more than women globally. The nicotine content of cigarette is small (10 to 12 mg) and a smoker inhales about 1.1 to 1.8 mg of nicotine from each cigarette smoked to its entire length; this plant alkaloid stimulates the central nervous system, causes either ganglionic stimulation in low doses or ganglionic blockade in high doses, and smokers can develop a moderate to heavy physical dependence. Among other numerous substances, several are cancerogenic, and about 98 percent of lung cancer deaths are caused due to tobacco smoke. Nicotine addiction is often more severe than alcohol addiction. Smoking also may complicate anesthetic management, and passive smoking increases the rate of perioperative airway complications in the children of smokers, too. Preoperative abstinence from tobacco is required for surgical patients and it offers an opportunity for smokers to quit permanently. Physicians have an important role in helping smokers to quit tobacco or e-cigarettes, but if a doctor is a smoker himself, his antismoking influence may be deficient. Since a significant percentage of medical students are smokers, it is worth influencing them to stop the habit. The best way is to introduce tobacco modules, stimulating students to participate in anti-smoking campaigns, offer non-smoking hospitals, non-smoking university campuses, non-smoking dormitories, and to provide medical assistance to student smokers who wish to quit.