Human Defensins from antivirals to vaccine adjuvants: rediscovery of the innate immunity arsenal

: Human defensins are a class of antimicrobial peptides, belonging to the innate immunity system. These peptides are expressed at the level of respiratory tract (both upper and lower) where they represent the first line of defense against pathogens; they are also known for their activity against different viruses, acting through diverse mechanisms, including direct binding to the virus, inhibition of viral replication, and aggregation of virions. It has been recently reported they are also effective against SARS-CoV-2. Moreover, they influence the immune response stimulating it in the challenge against microorganisms. An intriguingly potential application of defensin is related to their use as vaccine adjuvants; indeed, some in silico studies suggested their efficacy in boosting the immune response. Since the long-term persistence of acquired immunity against SARS-CoV-2 triggered by the currently employed vaccines is not known, natural agents with enhancing effects, such as defensins, administered with the vaccine, can be an interesting and attractive alternative.

A Review on Himalayan Medicinal Plants against Cancer

Background: Plants contributed numerous novel compounds for prophylactic and curative medicine to modern science.They are the important source of natural agents used in various pharmaceutical industries. Himalayan plants are abundant in various secondary metabolites such as anthraquinones, flavonoids, tannins, alkaloids and terpenes. The Himalayan plants grown in high altitude and have around 6500 years old history as traditional medicines. Aim: This review article systematically presents information onHimalayan medicinal plants having anti-cancer potentials. Methodology: Around 160 articles were reviewed by using online search engines like PubMed, Scopus, Google Scholar, Web of Science, and floras of different Himalayan countries. Results: An attempt has been made to review anticancer plants and active constituents isolated from several anti-cancerous plants of Himalayan regions. Eighty three anticancer plants are reported in this review and total twenty two active chemical constituents including phenolic compounds, glycosides, terpenoidsand alkaloids from the plants were reported active against various cancer cell lines. Conclusion: Several synthetic agents are used to cure cancer but number of undesired side effects occurs during chemotherapy. Hence, the research is going on to investigate natural therapies, such as the use of the plant derived productsin cancer treatment. They may reduce adverse side effects.

A Specific Mixture of Propolis and Carnosic Acid Triggers a Strong Fungicidal Action against Cryptococcus neoformans

Current antifungal chemotherapy against the prevalent basidiomycete Cryptococcus neoformans displays some drawbacks. This pathogenic fungus is refractory to echinocandins, whereas conventional treatment with amphotericin B plus 5-fluorocytosine has a limited efficacy. In this study, we explored the potential cryptococcal activity of some natural agents. After conducting a screening test with a set of propolis from different geographical areas, we selected an extract from China, which displayed a certain cytotoxic activity against C. neoformans, due to this extract being cheap and easily available in large amounts. The combination of this kind of propolis with carnosic acid in a 1:4 ratio induced a stronger fungicidal effect, which occurred following a synergistic pattern, without visible alterations in external cell morphology. Furthermore, several carnosic acid–propolis formulations applied onto preformed biofilms decreased the metabolic activity of the sessile cells forming biofilms. These data support the potential application of mixtures containing these two natural extracts in the design of new antifungal strategies in order to combat opportunistic infections caused by prevalent pathogenic fungi.

Natural Superdisintegrants for the Formulation of Orally Disintegrating Tablets

Oral route is the most favoured and preferred route for the administration for most of the dosage forms because it offers so many advantages over other routes of administration. Sometimes the oral route is associated with a problem called dysphagia. This condition can be seen in a population of paediatric, geriatric, patients with neurological problems, bedridden patients and so on. In order to overcome such a problem orodispersible tablets will be a better choice, because it will disintegrate within seconds when comes in contact with saliva. Natural agents offers so many advantages like nontoxic, easy availability, low cost, biocompatible and biodegradable in nature over synthetic agents. This superdisintegrants will cause the increase in drug release and decrease the disintegration time. This natural superdisintegrants will be a good option for the preparation of ODTs. Keywords: orodispersible tablets, natural superdisintegrants, advantages, dysphagia .

Development and Characterization of Bioactive Polypropylene Films for Food Packaging Applications

Bioactive polypropylene (PP) films with active agents) presence for food packaging application have been prepared and characterized. The novel modified PP films were obtained via PP/additives systems regranulation and cast extrusion. The influence of two types of plasticizers (natural agents as well as commercial synthetic product) and bioactive additives on final features, e.g., mechanical properties, was evaluated. Moreover, the biocidal activity of the films was determined. Due to their functional properties, they are developed as additives to packaging plastic materials such as polyolefins. The study results presented in our work may indirectly contribute to environmental protection by reducing food waste. The aim of the work was to obtain innovative, functional packaging materials with an ability to prolong the shelf life of food products. The best antimicrobial properties were observed for the sample based on 5 wt.% oregano oil (OO) and 5 wt.% cedar oil (OC) in PP matrix. A microbial test revealed that the system causes total reduction in the following microorganisms: B. subtilis, E. coli, S. aureus, P. putida, C. albicans, A. alternata, F. oxysporum.

PSXV-7 The mixture of herbal extracts that change the microbiome of the cattle rumen

Today, the search for new antibacterial natural agents based on plant raw materials is relevant. These raw materials have promising secondary metabolites that reduce the formation of methane in the ruminant scar. The aim of this study was to evaluate the effect of the following extracts: oak bark+birch leaves (I group) (250 ml/head per day), oak bark + St. John’s wort grass (250 ml / head per day; II group) and birch leaves + St. John’s wort grass (III group; 250 ml/head per day) on the rumen microbiota of large cattle, against the background of control (C). Extracts added to the water of calves with rumen fistula (dairy breed, age 12 months, diet -70 % of hay, 30 % of grain feed, duration is 14 days). The microflora analyzed using high efficiency 16S rRNA (Illumina) gene sequencing. Plant extracts prepared by purification, grinding (1–2 mm) and extraction in a water bath (for 30 min, 70 ° C) and filtration. According to the study results, the inclusion of extracts led to increase of the Bacteroidetes phylum for 1.11–3.69 % in the practical groups in comparison with C. A decrease was obtained for Firmicutes for 2.06–3.55 % (p 0.05) and Proteobacteria. In the I group bacteria of the class Bacteroides increased by 0.9–5.64% and Candidatus Saccharibacteria increased by 0.25% (P = 0.05). In the III group the value increased by 0.64 % (P = 0.05). Compared to C at the level of the family Prevotellaceae dominated in all experimental groups by 1.04–9.11 % (P ≤ 0.05), in group III Bacteroidaceae dominated by 0.27 % and Rikenellaceae by 0.14 %. This contributes to the regulation of opportunistic microorganisms without harmful effects on the rumen microbiota. This research was performed with financial support from the project 0761-2019-0005.

The Dominance of Chitosan Hydrochloride over Modern Natural Agents or Basic Substances in Efficacy against Phytophthora infestans, and Its Safety for the Non-Target Model Species Eisenia fetida

Growing pressure to reduce the environmental pesticide burden has the greatest impact on agriculture and crop protection. There is an enormous increase in the demand for research on new, effective, naturally based agents that do not pose an environmental risk. Phytophthora infestans is one of the most destructive phytopathogens, especially in cases where synthetic fungicides are not allowed. This paper describes the high efficacy and safety of the natural polymer chitosan under in vitro and in vivo conditions and its dominance over other natural agents or products. Chitosan demonstrated the highest efficacy against P. infestans. A concentration of 0.2–0.4% was highly effective. The protective effect of chitosan was 99.3% in natural conditions. Direct activity, equivalent to synthetic fungicides (MIC50 0.293 mg/mL), was confirmed. Chitosan was rated non-toxic to useful non-target species. We promote further chitosan expansion within legislation and implementation of chitosan as a safe substance that could reduce the pesticide burden, particularly in eco-friendly plant protection and production of non-harmful foods.

Superior Technique for the Production of Agarose Dressing Containing Sericin and Its Wound Healing Property

Finding a simple and eco-friendly production technique that matches to the natural agent and results in a truly valuable natural scaffold production is still limited amongst the intensively competitive natural scaffold development. Therefore, the purpose of this study was to develop natural scaffolds that were environmentally friendly, low cost, and easily produced, using natural agents and a physical crosslinking technique. These scaffolds were prepared from agarose and sericin using the freeze-drying method (D) or freeze-thawing together with the freeze-drying method (TD). Moreover, plasticizers were added into the scaffold to improve their properties. Their physical, mechanical, and biological properties were investigated. The results showed that scaffolds that were prepared using the TD method had stronger bonding between sericin and other compounds, leading to a low swelling ratio and low protein release of the scaffolds. This property may be applied in the development of further material as a controlled drug release scaffold. Adding plasticizers, especially glycerin, into the scaffolds significantly increased elongation properties, leading to an increase in elasticity of the scaffold. Moreover, all scaffolds could activate cell migration, which had an advantage on wound healing acceleration. Accordingly, this study was successful in developing natural scaffolds using natural agents and simple and green crosslinking methods.