Influenza viruses represent a leading cause of high morbidity and mortality worldwide. Approaches for fighting flu are seasonal vaccines and some antiviral drugs. The development of the seasonal flu vaccine requires a great deal of effort, as careful studies are needed to select the strains to be included in each year’s vaccine. Antiviral drugs available against Influenza virus infections have certain limitations due to the increased resistance rate and negative side effects. The highly mutative nature of these viruses leads to the emergence of new antigenic variants, against which the urgent development of new approaches for antiviral therapy is needed. Among these approaches, one of the emerging new fields of “peptide-based therapies” against Influenza viruses is being explored and looks promising. This review describes the recent findings on the antiviral activity, mechanism of action and therapeutic capability of antiviral peptides that bind HA, NA, PB1, and M2 as a means of countering Influenza virus infection.

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Background The potential of essential oils (EOs) and of their principal constituents for eradication of biofilm and at the same time the research of new potential acetylcholinesterase inhibitors is gaining increasing interest in last years. The aims of this study were to determine the chemical composition and to evaluate the antibacterial, cytotoxic, and anti-acetylcholinesterase properties of Myrtus communis leaves essential oil and its main constituents. Methods Essential oil was obtained by hydrodistillation of M. communis L. leaves and was analyzed by GC and GC–MS. The antimicrobial activity was carried out against both gram-negative and gram-positive bacteria. The microdilution method was used to estimate the minimum inhibitory concentrations (MICs). Then, the capacity of essential oil and its main constituent to inhibit biofilm growth, with the method of O’Toole and Kolterand, and the metabolic activity of biofilm cells through the MTT colorimetric method were evaluated at different times. Moreover, was studied the potential cytotoxic activity against SH-SY5Y cell line with MTT assay and the anti-acetylcholinesterase activity using Ellman’s assay. Results Myrtenyl-acetate, 1,8 cineole, α-pinene, and linalool were the main components in the EO. The myrtle EO, at the minimum tested dose (0.4 mg/ml), inhibited S. aureus biofilm by 42.1% and was capable of inhibiting the biofilm cell metabolism in all tested strains, except Staphylococcus aureus. Moreover, the EO showed good cytotoxic and anti-acetylcholinesterase activities IC50 of 209.1 and 32.8 μg/ml, respectively. Conclusions The results suggest that myrtle EO and its main constituents could be used as possible products that could act against the resistant pathogenic species E. coli, P. aeruginosa, L. monocytogenes and S. aureus, on the other hand, as possible coadjutants in the treatment of neurological diseases.

In recent years, peptides have gained more success as therapeutic compounds. Nowadays, the preferred method to obtain peptides is solid-phase peptide synthesis (SPPS), which does not respect the principles of green chemistry due to the large number of toxic reagents and solvents used. The aim of this work was to research and study an environmentally sustainable solvent able to replace dimethylformamide (DMF) in fluorenyl methoxycarbonyl (Fmoc) solid-phase peptide synthesis. Herein, we report the use of dipropyleneglycol dimethylether (DMM), a well-known green solvent with low human toxicity following oral, inhalant, and dermal exposure and that is easily biodegradable. Some tests were needed to evaluate its applicability to all the steps of SPPS, such as amino acid solubility, resin swelling, deprotection kinetics, and coupling tests. Once the best green protocol was established, it was applied to the synthesis of different length peptides to study some of the fundamental parameters of green chemistry, such as PMI (process mass intensity) and the recycling of solvent. It was revealed that DMM is a valuable alternative to DMF in all steps of solid-phase peptide synthesis.