The caffeic acid in aqueous extract of Tournefortia sarmentosa enhances neutrophil phagocytosis of Escherichia coli

The influence of Salvia cadmica Boiss. extracts on the M1/M2 polarization of macrophages primed with Helicobacter pylori lipopolysaccharide in conjunction with NF-kappa B activation, production of cytokines, phagocytic activity and total DNA methylation

ETHNOPHARMACOLOGICAL RELEVANCE

The large number of secondary derivatives have been isolated from the genus Salvia with about 700 species, and used in the pharmacopoeia throughout the world. Various biological properties of Salvia formulations have been reported including as antioxidant, antimicrobial, hypotensive, anti-hyperglycemia, anti-hyperlipidemia, anti-cancer, and skin curative. Salvia cadmica Boiss. root and aerial part extracts enriched with polyphenols are bactericidal towards gastric pathogen Helicobacter pylori (Hp) and diminish deleterious effects induced by Hp lipopolysaccharide (LPS) towards gastric epithelial cells.

AIM OF THIS STUDY

To examine the influence of S. cadmica extracts on the M1/M2 polarization of macrophages primed with Hp LPS vs standard LPS Escherichia coli (Ec), and the macrophage cytokine as well as phagocytic activity, which are affected during Hp infection.

MATERIAL AND METHODS

Macrophages derived from THP-1 human monocytes primed with LPS Hp/Ec and/or S. cadmica extracts, were examined for the biomarkers of activation (surface, cytoplasmic or soluble), and phagocytic capacity. The bone marrow macrophages of Caviaporcellus were used to determine the engulfment of Hp.

RESULTS

Priming of THP-1 cells (24h) with LPS Hp/Ec resulted in polarization of M1 macrophages, activation of nuclear factor kappa B, secretion of tumor necrosis factor (TNF)-α, interleukin (IL)-1 beta, macrophage chemotactic protein (MCP)-1, immunoregulatory IL-10, and production of reactive oxygen species. These effects were diminished after restimulation of cells with S. cadmica extracts. THP-1 macrophages exposed to studied extracts showed an increased phagocytic capacity, in conjunction with elevated CD11b/CD11d expression and enhanced production of inducible nitric oxide synthase. They also increased Hp engulfment by bone marrow macrophages. These effects were not related to a global DNA methylation.

CONCLUSIONS

S. cadmica extracts possess an immunomodulating activity, which might be useful in control of H. pylori LPS driven activity of macrophages.

Stereocomplexed microparticles loaded with Salvia cadmica Boiss. extracts for enhancement of immune response towards Helicobacter pylori

Controlled delivery of therapeutic substance gives numerous advantages (prevents degradation, improves uptake, sustains concentration, lowers side effects). To encapsulate Salvia cadmica extracts (root or aerial part), enriched with polyphenols with immunomodulatory activity, in stereocomplexed microparticles (sc-PLA), for using them to enhance the immune response towards gastric pathogen Helicobacter pylori. Microparticles were made of biodegradable poly(lactic acid) (PLA) and poly(D-lactic acid) (PDLA). Their stereocomplexation was used to form microspheres and enhance the stability of the obtained particles in acidic/basic pH. The release of Salvia cadmica extracts was done in different pH (5.5, 7.4 and 8.0). The obtained polymers are safe in vitro and in vivo (guinea pig model). The sc-PLA microparticles release of S. cadmica extracts in pH 5.5, 7.4, and 8.0. S. cadmica extracts enhanced the phagocytic activity of guinea pig bone marrow-derived macrophages, which was diminished by H. pylori, and neutralized H. pylori driven enhanced production of tumor necrosis factor (TNF)-α and interleukin (IL)-10. The sc-PLA encapsulated S. cadmica extracts can be recommended for further in vivo study in guinea pigs infected with H. pylori to confirm their ability to improve an immune response towards this pathogen.

Phagocytosis, Degranulation and Extracellular Traps Release by Neutrophils-The Current Knowledge, Pharmacological Modulation and Future Prospects

Neutrophils are crucial elements of innate immune system, which assure host defense via a range of effector functions, such as phagocytosis, degranulation, and NET formation. The latest literature clearly indicates that modulation of effector functions of neutrophils may affect the treatment efficacy. Pharmacological modulation may affect molecular mechanisms activating or suppressing phagocytosis, degranulation or NET formation. In this review, we describe the role of neutrophils in physiology and in the course of bacterial and viral infections, illustrating the versatility and plasticity of those cells. This review also focus on the action of plant extracts, plant-derived compounds and synthetic drugs on effector functions of neutrophils. These recent advances in the knowledge can help to devise novel therapeutic approaches via pharmacological modulation of the described processes.

Baccharis dracunculifolia DC (Asteraceae) selectively modulates the effector functions of human neutrophils

OBJECTIVES

To examine whether the hydroalcoholic extract from Baccharis dracunculifolia leaves (BdE) modulates the human neutrophil oxidative metabolism, degranulation, phagocytosis and microbial killing capacity.

METHODS

In-vitro assays based on chemiluminescence, spectrophotometry, flow cytometry and polarimetry were used, as well as docking calculations.

KEY FINDINGS

At concentrations that effectively suppressed the neutrophil oxidative metabolism elicited by soluble and particulate stimuli (<10 μg/ml), without clear signs of cytotoxicity, BdE (1) inhibited NADPH oxidase and myeloperoxidase activity; (2) scavenged H₂ O₂ and HOCl; (3) weakly inhibited phagocytosis; and (4) did not affect neutrophil degranulation and microbial killing capacity, the expression levels of TLR2, TLR4, FcγRIIa, FcγRIIIb and CR3 and the activity of elastase and lysozyme. Caffeic acid, one of the major B. dracunculifolia secondary metabolites, did not inhibit phagocytosis but interfered in the myeloperoxidase-H₂ O₂ -HOCl system by scavenging H₂ O₂ and HOCl, and interacting with the catalytic residues His-95, Arg-239 and Gln-91.

CONCLUSIONS

BdE selectively modulates the effector functions of human neutrophils, inhibits the activity of key enzymes and scavenges physiological oxidant species. Caffeic acid contributes to lower the levels of oxidant species. Our findings help to unravel the mechanisms by which these natural products exert immunomodulatory action towards neutrophils.