Arabino-galactan proteins from Pistacia lentiscus var. chia: isolation, characterization and biological function

Phytochemicals: A Promising Weapon in the Arsenal against Antibiotic-Resistant Bacteria

The extensive usage of antibiotics and the rapid emergence of antimicrobial-resistant microbes (AMR) are becoming important global public health issues. Many solutions to these problems have been proposed, including developing alternative compounds with antimicrobial activities, managing existing antimicrobials, and rapidly detecting AMR pathogens. Among all of them, employing alternative compounds such as phytochemicals alone or in combination with other antibacterial agents appears to be both an effective and safe strategy for battling against these pathogens. The present review summarizes the scientific evidence on the biochemical, pharmacological, and clinical aspects of phytochemicals used to treat microbial pathogenesis. A wide range of commercial products are currently available on the market. Their well-documented clinical efficacy suggests that phytomedicines are valuable sources of new types of antimicrobial agents for future use. Innovative approaches and methodologies for identifying plant-derived products effective against AMR are also proposed in this review.

Traditional uses, phytochemistry and pharmacology of Chios mastic gum (Pistacia lentiscus var. Chia, Anacardiaceae): A review

ETHNOPHARMACOLOGICAL RELEVANCE

Chios mastic gum constitutes a unique Greek product, produced exclusively in the southern part of the island of Chios. References about its use from local populations for the treatment of gastrointestinal disorders or as a cosmetic agent can even be encountered in ancient texts of Galen, Theophrastus and Dioscorides. Nowadays, this versatile resin has been rediscovered, not only as a traditional remedy and aromatic agent, but as a potent phytotherapeutic product with various biological properties.

AIM OF THE STUDY

The aim of this study is to quote the summation of the ethnopharmacology, phytochemical profile and pharmacological properties of the resin of Pistacia lentiscus var. Chia and thus provide the scientific community with a summary of the research conducted so far. Furthermore, perspectives and uses are being discussed and studied so as to broaden the field of its applications.

MATERIALS AND METHODS

A comprehensive review of the literature on Pistacia lentiscus var. Chia was performed using as resources scientific databases such as Scopus, Sciencedirect, Pubmed and Web of science, studies and traditional books provided by the Chios Mastiha Growers Association as well as PhD and Master' s theses.

RESULTS

Chios mastic gum has been used as a traditional medicine over the last 2500 years. More than 120 chemical compounds have been identified in the resin and the major components are a natural polymer, acidic and neutral triterpenes and volatile secondary metabolites. Several plant extracts and compounds have been studied for their antibacterial, anti-inflammatory, antioxidant, anti-ulcer, anti-diabetic, cardioprotective and anti-cancer properties in vitro and in vivo. Clinical interventions and trials have also showed the therapeutic potential of Chios mastic gum. In 2015 Pistacia lentiscus L., resin (mastic) was recognized as a herbal medicinal product with traditional use by the European Medicines Agency (EMA) with two therapeutic indications (mild dyspeptic disorders & skin inflammation/healing of minor wounds). Over the last years, Chios mastic gum is widely involved in medicinal products, food supplements and cosmetics and has become object of study, also in the field of Pharmacotechnology.

CONCLUSIONS

Chios mastic's beneficial properties have been demonstrated in the treatment of gastrointestinal disorders, wound healing, skin inflammations, plasma lipid and blood sugar reduction and oral care. These properties are attributed to triterpenes and volatile compounds. However, because of the resin's chemical complexity and the lack of commercial standards for its main compounds, there is a notable gap in literature concerning the biological evaluation of CMG's isolated components. Therefore, future research should focus on the development of efficient extraction, isolation and analysis techniques in order to unravel CMG's full pharmacological potential.

Plant-Derived Products as Antibacterial and Antifungal Agents in Human Health Care

A number of papers reporting antimicrobial properties of extracts, essential oils, resins and various classes of compounds isolated from higher plants have been published in recent years; however, a comprehensive analysis of plant-derived antimicrobial agents currently applied in practice for the improvement of human health is still lacking. This review summarizes data on clinical efficacy, antimicrobial effects and the chemistry of commercially available antibacterial and antifungal agents of plant origin currently used in the prevention and treatment of gastrointestinal, oral, respiratory, skin, and urinary infections. As a result of an analysis of the literature, more than 40 plant-derived over-the-counter pharmaceuticals, dietary supplements, cosmetics, herbal medicines, and functional foods containing complex mixtures (e.g. Glycyrrhiza glabra extract, Melaleuca alternifolia essential oil, and Pistacia lentiscus resin), pure compounds (e.g. benzoic acid, berberine, eucalyptol, salicylic acid and thymol) as well as their derivatives and complexes (e.g. bismuth subsalicylate and zinc pyrithione) have been identified. The effectiveness of many of these products is illustrated by results of clinical trials and supported by data on there in vitro antimicrobial activity. A broad spectrum of various commercial products currently available on the market and their welldocumented clinical efficacy suggests that plants are prospective sources for the identification of new types of antimicrobial agents in future. Innovative approaches and methodologies for effective proof-of-concept research and the development of new types of plant-derived products effective against recently emerging problems related to human microbial diseases (e.g. antimicrobial resistance) are also proposed in this review.

Helicobacter pylori neutrophil activating protein as target for new drugs against H. pylori inflammation

Helicobacter pylori (H. pylori) infection is among the most common human infections and the major risk factor for peptic ulcer disease and gastric cancer. Within this work we present the implication of C-terminal region of H. pylori neutrophil activating protein in the stimulation of neutrophil activation as well as the evidence that the C-terminal region of H. pylori activating protein is indispensable for neutrophil adhesion to endothelial cells, a step necessary to H. pylori inflammation. In addition we show that arabino galactan proteins derived from chios mastic gum, the natural resin of the plant Pistacia lentiscus var. Chia inhibit neutrophil activation in vitro.

The C-terminal region of HPNAP activates neutrophils and promotes their adhesion to endothelial cells

Entire Helicobacter Pylori Neutrophil Activated Protein (HPNAP) and its truncated forms NH(2)-terminal region HPNAP(1-57) and C-terminal region HPNAP(58-144) after cloning into pET29c vector, purification and removal of LPS traces were subjected to human neutrophil activation. Our results revealed that the C-terminal region of HPNAP is indispensable for human neutrophil stimulation and their further adhesion to endothelial cells - a step necessary to H. pylori inflammation - in a ratio equal to that exhibited by the entire protein. In addition, experiments concerning the implication of Arabino-Galactan-Proteins (AGPs) derived from Chios Mastic Gum (CMG), the natural resin of the plant Pistacia lentiscus var. Chia revealed the inhibition of neutrophil activation and therefore their adhesion to endothelial cells, in vitro. Both, the involvement of HPNAP C-terminal region in stimulation-adhesion of neutrophils to endothelial cells as well as the inhibition of this process by AGPs have to be further investigated and may be exploited in a future anti-inflammatory therapy for H. pylori patients.