Xanthine Oxidase Inhibitor, Febuxostat Is Effective against 5-Fluorouracil-Induced Parotid Salivary Gland Injury in Rats Via Inhibition of Oxidative Stress, Inflammation and Targeting TRPC1/CHOP Signalling Pathway

Facilitating Nitrite-Derived S-Nitrosothiol Formation in the Upper Gastrointestinal Tract in the Therapy of Cardiovascular Diseases

Cardiovascular diseases (CVDs) are often associated with impaired nitric oxide (NO) bioavailability, a critical pathophysiological alteration in CVDs and an important target for therapeutic interventions. Recent studies have revealed the potential of inorganic nitrite and nitrate as sources of NO, offering promising alternatives for managing various cardiovascular conditions. It is now becoming clear that taking advantage of enzymatic pathways involved in nitrite reduction to NO is very relevant in new therapeutics. However, recent studies have shown that nitrite may be bioactivated in the acidic gastric environment, where nitrite generates NO and a variety of S-nitrosating compounds that result in increased circulating S-nitrosothiol concentrations and S-nitrosation of tissue pharmacological targets. Moreover, transnitrosation reactions may further nitrosate other targets, resulting in improved cardiovascular function in patients with CVDs. In this review, we comprehensively address the mechanisms and relevant effects of nitrate and nitrite-stimulated gastric S-nitrosothiol formation that may promote S-nitrosation of pharmacological targets in various CVDs. Recently identified interfering factors that may inhibit these mechanisms and prevent the beneficial responses to nitrate and nitrite therapy were also taken into consideration.

Atrophy and Inflammatory Changes in Salivary Glands Induced by Oxidative Stress after Exposure to Drugs and Other Chemical Substances: A Systematic Review

Background and Objectives: Oxidative stress is involved in the alterations at the level of salivary glands, being the cause of oral pathologies like xerostomia, periodontitis, gingivitis, leucoplakia, and cancer. It is known that antioxidants can reverse changes induced by drugs or other chemicals in some organs, but the question is whether these substances can reduce or revert the effects of oxidative stress at the salivary gland level. Our aim was to find histopathological data at the level of salivary glands supporting the hypothesis of the reversal of oxidative stress-induced changes after the treatment with substances with antioxidant effect. Materials and Methods: A systematic search was conducted in PubMed, Science Direct, and Springer databases, including research articles on oxidative stress histological aspects and oxidative stress biomarkers induced by drugs or other chemicals on salivary glands. Results: Out of 1756 articles, 25 articles were selected with data on tissue homogenate used for biochemical analysis of oxidative and antioxidative markers, along with routine hematoxylin eosin (HE) and immunohistochemical analysis used for histopathological and immunohistochemical diagnosis. Drugs (antineoplastic drugs, antibiotics, and analgesics), alcohol, heavy metals, and fluoride can cause oxidative stress, resulting in morphological changes in different tissues, including in salivary glands. There are many antioxidants but only a few were evaluated regarding the effects on salivary glands in animal studies, such as hesperidin and selenium, which can reverse the damage induced by cyclophosphamide; 10-dehydrogingerdione (10-DHGD), a compound extracted from ginger, which has a protective effect against the oxidative stress and apoptosis induced by tramadol; and glycyrrhizic acid, which may repair the injuries incurred after the administration of sodium nitrite. Conclusions: Substances such as hesperidin, selenium, 10-dehydrogingerdione, and glycyrrhizic acid are antioxidants with proven restorative effects on salivary glands for the damage induced by oxidative stress after exposure to drugs and other chemical substances; however, demonstrating their similar effects in human salivary glands is challenging.

Diacerein modulates TLR4/ NF-κB/IL-1β and TRPC1/CHOP signalling pathways in gentamicin-induced parotid toxicity in rats

The present study aimed to identify the possible protective effect of diacerein (DIA) on gentamicin (GNT)-induced parotid toxicity in rats. DIA was administered in the presence and absence of GNT. Thirty-two Wistar adult male rats were randomly arranged into four groups: control, DIA (50 mg/kg/day), GNT (100 mg/kg) and GNT+DIA groups for 8 days. Parotid oxidative stress parameters, besides inflammatory and apoptotic biomarkers, were evaluated. Salivary flow rate, transient receptor potential canonical 1 (TRCP1), and C/EBP homologous protein (CHOP) in parotid tissue were measured. A parotid histopathological examination and an interleukin-1 beta (IL-1β) immunohistochemical study were also performed. GNT significantly increased parotid oxidative stress, inflammatory, apoptotic and CHOP biomarkers with decreased salivary flow rate and TRCP1 level. A histopathological picture of parotid damage and high IL-1β immunoexpression were detected. DIA significantly normalized the distributed oxidative, inflammatory and apoptotic indicators, CHOP and TRCP1, with a prompt improvement in the histopathological picture and a decrease in IL-1β immunoexpression. These results reported that DIA protects against GNT-induced parotid toxicity via modulation of TLR4/NF-κB/IL-1β and TRPC1/CHOP signalling pathways.

Pregnancy and COVID-19: high or low risk of vertical transmission

Coronavirus disease 19 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome 2 (SARS-CoV-2). Throughout the pandemic, evidence on the effects of COVID-19 during pregnancy has been inadequate due to the limited number of studies published. Therefore, the objective of this systematic review was to evaluate current literature regarding the effects of COVID-19 during pregnancy and establish pregnancy outcomes and vertical and perinatal transmission during pregnancy. Multiple databases were searched, including Embase, Medline, Web of Science, Scopus, and Cochrane Central Register of Control Clinical Trials, using the following keywords: [Pregnancy] AND [COVID-19 OR SARS-CoV-2 OR nCoV-19] OR [Perinatal transmission, Vertical transmission (VT), Pregnancy complications], [Pregnancy] AND [Hyperinflammation OR Cytokine storm]. We excluded in vitro and experimental studies, but also ex-vivo and animal study methods. To exclude the risk of bias during data collection and interpretation, all included studies were peer-reviewed publications. This review is estimated to tabulate the study intervention characteristics and compare them against the planned groups for each synthesis. Our findings showed that pregnant women are commonly susceptible to respiratory viral infections and severe pneumonia due to physiological immune suppression and pregnancy-induced changes. VT of SARS-CoV-2 infection during pregnancy is associated with a great deal of controversy and conflict. However, there is still no robust clinical evidence of VT. Furthermore, the clinical presentation and management of COVID-19 during pregnancy are nearly identical to those of non-pregnant women. Finally, chloroquine and remdesivir are the only two drugs evaluated as adequate for the management of COVID-19 during pregnancy.