The Gut Microbiota and Major Depressive Disorder: Current Understanding and Novel Therapeutic Strategies.

Major depressive disorder (MDD) is a common neuropsychiatric challenge that primarily targets young females. MDD as a global disorder has a multifactorial etiology related to the environment and genetic background. A balanced gut microbiota is one of the most important environmental factors involved in human physiological health. The interaction of gut microbiota components and metabolic products with the hypothalamic-pituitary-adrenal system and immune mediators can reverse depression phenotypes in vulnerable individuals. Therefore, abnormalities in the quantitative and qualitative structure of the gut microbiota may lead to the progression of MDD. In this review, we have presented an overview of the bidirectional relationship between gut microbiota and MDD, and the effect of pre-treatments and microbiomebased approaches, such as probiotics, prebiotics, synbiotics, fecal microbiota transplantation, and a new generation of microbial alternatives, on the improvement of unstable clinical conditions caused by MDD.

Hepatic Disorders and COVID-19: From Pathophysiology to Treatment Strategy.

Following the SARS-CoV-2 outbreak and the subsequent development of the COVID-19 pandemic, organs such as the lungs, kidneys, liver, heart, and brain have been identified as priority organs. Liver diseases are considered a risk factor for high mortality from the COVID-19 pandemic. Besides, liver damage has been demonstrated in a substantial proportion of patients with COVID-19, especially those with severe clinical symptoms. Furthermore, antiviral medications, immunosuppressive drugs after liver transplantation, pre-existing hepatic diseases, and chronic liver diseases such as cirrhosis have also been implicated in SARS-CoV-2-induced liver injury. As a result, some precautions have been taken to prevent, monitor the virus, and avoid immunocompromised and susceptible individuals, such as liver and kidney transplant recipients, from being infected with SARS-CoV-2, thereby avoiding an increase in mortality. The purpose of this review was to examine the impairment caused by SARS-CoV-2 infection and the impact of drugs used during the pandemic on the mortality range and therefore the possibility of preventive measures in patients with liver disease.

Severe acute respiratory syndrome coronavirus 2 infection: Role of interleukin-6 and the inflammatory cascade.

Since December 2019, a novel coronavirus that represents a serious threat to human lives has emerged. There is still no definite treatment for severe cases of the disease caused by this virus, named coronavirus disease 2019 (COVID-19). One of the most considered treatment strategies targets the exaggerated immune regulator, and interleukin (IL)-6 is a crucial pro-inflammatory mediator. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases show an elevated level of IL-6 related to disease severity. IL-6 activity can be inhibited by the following: IL-6 itself, IL-6 signaling pathways such as Janus kinase and signal transducer and activator of transcription (JAK-STAT), gp130, IL-6R, and downstream activated ILs, such as IL-17 and IL-6 cytokine. Currently, according to these studies and their results, IL-6 blockade with anti-IL-6 or its receptor antibodies such as tocilizumab in COVID-19 is beneficial in severe cases and may reduce the mortality rate. JAK-STAT inhibitors block the cytokine storm by inhibiting several crucial pro-inflammatory mediators such as TNF-α and IL-6 and have shown various results in clinical trials. IL-6 induces IL-17 secretion, and IL-17 is involved in the pathogenesis of inflammatory processes. Clinical trials of anti-IL-17 drugs are currently recruiting, and anti-gp130 antibody is preclinical. However, this agent has shown positive effects in inflammatory bowel disease clinical trials and could be tested for SARS-CoV-2. This study aimed to review the role of IL-6 in the cytokine storm and studies regarding IL-6 and blockade of its inflammatory pathways in COVID-19 to determine if any of these agents are beneficial for COVID-19 patients.