Santalum album extract exhibits neuroprotective effect against the TLR3-mediated neuroinflammatory response in human SH-SY5Y neuroblastoma cells.

Neuroinflammation is an inflammatory response in the nervous system that is associated with various neurological diseases including Alzheimer's diseases and others. Many studies evaluated the anti-inflammatory potential of Santalum album (S. album) extract, but none of them analyzed its effects against neuroinflammatory response in vitro. In addition, the precise mechanism underlying the anti-inflammatory effect of the extract has not yet been elucidated. Therefore, in this study, we investigated the effect of S. album extract on modulation of toll-like receptor 3 (TLR3) agonist polyinosnic-polycytidylic acid (PolyI:C)-induced neuroinflammatory response in human neuroblastoma cells. The TLR3-mediated immune response was differentially modulated by S. album extract in SH-SY5Y cells. In addition, treatment of cells with the conditioned medium (CM) of S. album extract significantly increased the mRNA levels of IFN-ß, IFN-α, MxA and OAS-1 and decreased IL-6, CXCL8, CCL2 and IP-10. S. album extract has indirectly affected the expression of IFNs and inflammatory cytokines in SH-SY5Y cells. Furthermore, the extract was able to modulate PolyI:C-induced inflammatory response in Caco2 cells. Overall, S. album was capable to attenuate PolyI:C-induced neuroinflammatory effect through the induction of TLR2, TLR4 and the modulation of TLR negative regulators of the TRAF3, IRF3 and NF-κB pathways.

Impact of gut microbiota: How it could play roles beyond the digestive system on development of cardiovascular and renal diseases.

In recent years, a significant interest in gut microbiota-host crosstalk has increased due to the involvement of gut bacteria on host health and diseases. Gut dysbiosis, a change in the gut microbiota composition alters host-microbiota interactions and induces gut immune dysregulation that have been associated with pathogenesis of several diseases, including cardiovascular diseases (CVD) and chronic kidney diseases (CKD). Gut microbiota affect the host, mainly through the immunological and metabolism-dependent and metabolism-independent pathways. In addition to these, the production of trimethylamine (TMA)/trimethylamine N-oxide (TMAO), uremic toxins and lipopolysaccharides (LPS) by gut microbiota are involved in the pathogenesis of CVD and CKD. Given the current approaches and challenges that can reshape the bacterial composition by restoring the balance between host and microbiota. In this review, we discuss the complex interplay between the gut microbiota, and the heart and the kidney, and explain the gut-cardiovascular axis and gut-kidney axis on the development and progression of cardiovascular diseases and chronic kidney diseases. In addition, we discuss the interplay between gut and kidney on hypertension or cardiovascular pathology.

The Gut Microbiota: How Does It Influence the Development and Progression of Liver Diseases.

The gut-liver axis plays important roles in both the maintenance of a healthy liver and the pathogenesis of liver diseases, where the gut microbiota acts as a major determinant of this relationship. Gut bacteria-derived metabolites and cellular components are key molecules that affect the function of the liver and modulate the pathology of liver diseases. Accumulating evidence showed that gut microbiota produces a myriad of molecules, including lipopolysaccharide, lipoteichoic acid, peptidoglycan, and DNA, as well as short-chain fatty acids, bile acids, trimethylamine, and indole derivatives. The translocation of these components to the liver exerts beneficial or pathogenic effects by interacting with liver immune cells. This is a bidirectional relationship. Therefore, the existence of crosstalk between the gut and liver and its implications on host health and diseases are essential for the etiology and treatment of diseases. Several mechanisms have been proposed for the pathogenesis of liver diseases, but still, the mechanisms behind the pathogenic role of gut-derived components on liver pathogenesis remain elusive and not understandable. This review discusses the current progress on the gut microbiota and its components in terms of the progression of liver diseases, and in turn, how liver diseases indirectly affect the intestinal function and induce intestinal inflammation. Moreover, this paper highlights the current therapeutic and preventive strategies used to restore the gut microbiota composition and improve host health.

Gut-Brain Axis: Role of Gut Microbiota on Neurological Disorders and How Probiotics/Prebiotics Beneficially Modulate Microbial and Immune Pathways to Improve Brain Functions.

The gut microbiome acts as an integral part of the gastrointestinal tract (GIT) that has the largest and vulnerable surface with desirable features to observe foods, nutrients, and environmental factors, as well as to differentiate commensals, invading pathogens, and others. It is well-known that the gut has a strong connection with the central nervous system (CNS) in the context of health and disease. A healthy gut with diverse microbes is vital for normal brain functions and emotional behaviors. In addition, the CNS controls most aspects of the GI physiology. The molecular interaction between the gut/microbiome and CNS is complex and bidirectional, ensuring the maintenance of gut homeostasis and proper digestion. Besides this, several mechanisms have been proposed, including endocrine, neuronal, toll-like receptor, and metabolites-dependent pathways. Changes in the bidirectional relationship between the GIT and CNS are linked with the pathogenesis of gastrointestinal and neurological disorders; therefore, the microbiota/gut-and-brain axis is an emerging and widely accepted concept. In this review, we summarize the recent findings supporting the role of the gut microbiota and immune system on the maintenance of brain functions and the development of neurological disorders. In addition, we highlight the recent advances in improving of neurological diseases by probiotics/prebiotics/synbiotics and fecal microbiota transplantation via the concept of the gut-brain axis.