Lithium and antidepressants: inhibiting eicosanoids, stimulating immunity, and defeating microorganisms

Lithium: Immunomodulatory and Anti-Infectious Activities

Lithium (Li), a well-known immunomodulatory agent, has been in use for the treatment of several infectious diseases. Li mainly acts through GSK3β inactivation and several other signalling pathways, which are directly involved in the activation of innate immune system. Li therapy has been shown to cause effective modulation of various inflammatory cytokines, and has also been shown to boost immunity in several disease models. Apart from treatment for mania, Li has also been proved to be effective against infections caused by viruses, bacteria, parasites, and certain life-style disorders. Its effects, ranging from common defensive capabilities to complex pathways for protection of human body, make Li extraordinary. Thus, Li is an absolute requirement that can be a solution for some of the immune related disorders. This review mainly focuses on pharmacology, immune reactions of different cell types, and anti-infectious activities of Li.

Pulsed Laser Deposited Biocompatible Lithium-Doped Hydroxyapatite Coatings with Antimicrobial Activity

Simple and lithium-doped biological-origin hydroxyapatite layers were synthesized by Pulsed Laser Deposition technique on medical grade Ti substrates. Cytotoxic effects of lithium addition and the biocompatibility of obtained coatings were assessed using three cell lines of human origin (new initiated dermal fibroblasts, immortalized keratinocytes HaCaT, and MG-63 osteosarcoma). Antimicrobial properties of obtained coatings were assessed on two strains (i.e., Staphylococcus aureus and Candida albicans), belonging to species representative for the etiology of medical devices biofilm-associated infections. Our findings suggest that synthesized lithium-doped coatings exhibited low cytotoxicity on human osteosarcoma and skin cells and therefore, an excellent biocompatibility, correlated with a long-lasting anti-staphylococcal and -fungal biofilm activity. Along with low fabrication costs generated by sustainable resources, these biological-derived materials demonstrate their promising potential for future prospective solutions—viable alternatives to commercially available biomimetic HA implants—for the fabrication of a new generation of implant coatings.

Enhancement of the antimicrobial performance of biocidal formulations used for the preservation of white mineral dispersions

Biocides play an important role in the preservation of white mineral dispersions (WMD). Due to the occurrence of biocide-resistant bacteria and technical limitations in the use of biocides, new preservation strategies are required-like the enhancement of biocides by non-biocidal compounds. The aim of this study was to evaluate the biocide enhancement performance of lithium against various biocide-resistant bacteria in WMD. Subsequently, the minimal enhancing concentration (MEC) of lithium and the bioavailability of lithium in respect to the mode of introduction into WMD were investigated. The antimicrobial performance of biocidal formulations comprising isothiazolinones and formaldehyde releasers or isothiazolinones and glutaraldehyde has been evaluated against the related resistant bacterial spectrum in the presence of lithium. The MEC of lithium ranged from 1,350 to 1,500 ppm (based on the liquid phase weight of a WMD with 75% solids) for formaldehyde releasers and glutaraldehyde-based biocidal formulations, respectively. The biocide enhancing property of lithium was independent of whether lithium was introduced into WMD via a lithium-neutralised dispersant, added during the calcium carbonate grinding step, or dosed into the final product. Lithium is a non-biocidal compound which has been discovered to be a potent and universal biocide enhancer. Lithium boosts the biocidal activity of various biocides and provides a novel technique to overcome biocide resistance in WMD. Such a biocide enhancer represents a breakthrough that offers a potential tool to revolutionise the consumption of biocidal agents in the WMD producing industry.

The sodium/hydrogen exchanger: a possible mediator of immunity

Immune cells such as macrophages and neutrophils provide the first line of defence of the immune system using phagocytosis, cytokine and chemokine synthesis and release, as well as Reactive Oxygen Species (ROS) generation. Many of these functions are positively coupled with cytoplasmic pH (pHi) and/or phagosomal pH (pHp) modification; an increase in pHi represents an important signal for cytokine and chemokine release, whereas a decrease in pHp can induce an efficient antigen presentation. However, the relationship between pHi and ROS generation is not well understood. In immune cells two main transport systems have been shown to regulate pHi: the Na+/H+ Exchanger (NHE) and the plasmalemmal V-type H+ ATPase. NHE is a family of proteins which exchange Na+ for H+ according to their concentration gradients in an electroneutral manner. The exchanger also plays a key role in several other cellular functions including proliferation, differentiation, apoptosis, migration, and cytoskeletal organization. Since not much is known on the relationship between NHE and immunity, this review outlines the contribution of NHE to different aspects of innate and adaptive immune responses such as phagosomal acidification, NADPH oxidase activation and ROS generation, cytokine and chemokine release as well as T cell apoptosis. The possibility that several pro-inflammatory diseases may be modulated by NHE activity is evaluated.

Role of omega-3 fatty acids as a treatment for depression in the perinatal period

OBJECTIVES

To consider the possible rationale and utility of omega-3 fatty acids as a treatment for depression in the perinatal period.

METHOD

A review of published and unpublished research was undertaken, using electronic databases, conferences proceedings and expert informants.

RESULTS

Relevant bodies of evidence include an epidemiological link between low fish intake and depression. Laboratory studies show correlations between low omega-3 fatty acid levels and depression, as well as reduced levels of omega-3 in non-depressed women during the perinatal period. Treatment studies using omega-3 in patients with mood disorders further support an omega-3 contribution, as do neuroscientific theories. Research into omega-3 and infant development also highlights potential effects of depletion in the perinatal period and supports infant safety and benefits of supplementation.

CONCLUSIONS

There is a relative lack of knowledge about the safety of standard antidepressants in the perinatal period. There is a clear need for more research into alternative treatments, such as omega-3 fatty acids, in the management of depression in the perinatal period.