Current Medicinal Chemistry - Volume 30, Issue 34, 2023

COVID-19 is caused by SARS-CoV-2 and leads to acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and extrapulmonary manifestations in severely affected cases. However, most of the affected cases are mild or asymptomatic. Cannabinoids (CBs) such as tetrahydrocannabinol (THC) and cannabidiol (CBD), which act on G-protein-coupled receptors called CB1 and CB2, have anti-inflammatory effects. Many published studies show that CBs are effective in various inflammatory disorders, viral infections, and attenuation of ALI and ARDS. Therefore, the present narrative review aimed to summarize the possible immunological role of CBs in COVID-19. The effects of CBs are controversial, although they have beneficial effects via CB2 receptors and adverse effects via CB1 receptors against ALI, ARDS, and hyperinflammation, which are hallmarks of COVID-19. The present narrative review has shown that CBs effectively manage ALI and ARDS by suppressing pro-inflammatory cytokines, which are common in COVID-19. Therefore, CBs may be used to manage COVID-19 because of their potent anti-inflammatory effects, suppressing pro-inflammatory cytokines and inhibiting inflammatory signaling pathways.

Systemic arterial hypertension (SAH) is a major risk factor for several secondary diseases, especially cardiovascular and renal conditions. SAH has a high prevalence worldwide, and its precise and early recognition is important to prevent the development of secondary outcomes. In this field, the study of biomarkers represents an important approach to diagnosing and predicting the disease and its associated conditions. The use of biomarkers in hypertension and hypertension-related disorders, such as ischemic stroke, intracerebral hemorrhage, transient ischemic attack, acute myocardial infarction, angina pectoris and chronic kidney disease, are discussed in this review. Establishing a potential pool of biomarkers may contribute to a non-invasive and improved approach for their diagnosis, prognosis, risk assessment, therapy management and pharmacological responses to a therapeutic intervention to improve patients' quality of life and prevent unfavorable outcomes.

Purine, one of the nucleotides, is an important substance for the metabolism and regulation of the body. Purine plays a key role not only in the composition of coenzymes but also in the supply of energy. Since purine was artificially synthesized, it has always been an important scaffold for respiratory diseases, cardiovascular diseases, and anti- tumor and anti-viral drugs. In addition to being widely used as competitive antagonists in the treatment of diseases, purines can be used in combination with other drugs and as precursors to benefit human life. Unfortunately, few new discoveries have been made in recent years. In this article, purine drugs in the market have been classified according to their different targets. In addition, their mechanism of action and structure-activity relationship have also been introduced. This paper provides details of the signaling pathways through which purine drugs can bind to the respective receptors on the surface of cells and cause consequent reactions within the cell, which finally affect the targeted diseases. The various receptors and biological reactions involved in the signaling for respective disease targets within the cells are discussed in detail.

Phenolic acids are now receiving a great deal of interest as pervasive human dietary constituents that have various therapeutic applications against chronic and age-related diseases. One such phenolic acid that is being utilized in traditional medicine is chlorogenic acid (CGA). It is one of the most readily available phytochemicals that can be isolated from the leaves and fruits of plants, such as coffee beans (Coffea arabica L.), apples (Malus spp.), artichoke (Cynara cardunculus L.), carrots (Daucus carota L.), betel (Piper betle L.), burdock (Arctium spp.), etc. Despite its low oral bioavailability (about 33%), CGA has drawn considerable attention due to its wide range of biological activities and numerous molecular targets. Several studies have reported that the antioxidant and anti-inflammatory potentials of CGA mainly account for its broad-spectrum pharmacological attributes. CGA has been implicated in exerting a beneficial role against dysbiosis by encouraging the growth of beneficial GUT microbes. At the biochemical level, its therapeutic action is mediated by free radical scavenging efficacy, modulation of glucose and lipid metabolism, down-regulation of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), IL-1β, and interferon-gamma (IFN-γ), upregulation of nuclear factor erythroid 2-related factor 2 (Nrf-2), and inhibition of the activity of nuclear factor- Κβ (NF-Κβ), thus helping in the management of diabetes, cardiovascular diseases, neurodegenerative disorders, cancer, hypertension etc. This review highlights the natural sources of CGA, its bioavailability, metabolism, pharmacotherapeutic potential, and underlying mechanisms of action for the clinical usefulness of CGA in the management of health disorders.

Reactive species (RS) are produced in aerobic and anaerobic cells at different concentrations and exposure times, which may trigger diverse responses depending on the cellular antioxidant potential and defensive devices. Study searches were carried out using the PubMed database of the National Library of Medicine-National Institutes of Health. Cellular RS include reactive oxygen (ROS), nitrogen (RNS), lipid (RLS) and electrophilic species that determine either cell homeostasis or dysfunctional biomolecules. The complexity of redox signalling is associated with the variety of RS produced, the reactivity of the target biomolecules with RS, the multiplicity of the counteracting processes available, and the exposure time. The continuous distortion in the prooxidant/ antioxidant balance favoring the former is defined as oxidative stress, whose intensity determines (i) the basal not harmful unbalance (oxidative eustress) at RS levels in the pM to nM range that supports physiological processes (e.g., immune function, thyroid function, insulin action) and beneficial responses to external interventions via redox signalling; or (ii) the excessive, toxic distortion (oxidative distress) at RS levels exceeding those in the oxidative eustress zone, leading to the unspecific oxidation of biomolecules and loss of their functions causing cell death with associated pathological states. The cellular redox imbalance is a complex phenomenon whose underlying mechanisms are beginning to be understood, although how RS initiates cell signalling is a matter of debate. Knowledge of this aspect will provide a better understanding of how RS triggers the pathogenesis and progression of the disease and uncover future therapeutic measures.